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Background PCSK9 (Proprotein Convertase Subtilisin/Kexin Type 9) increases LDL cholesterol (LDL-C) levels by stimulating the degradation of Low Density Lipoprotein receptors (LDL-r). This protein is now of high interest because antibodies which inhibit its effect on LDL-r are being developed. A severe hypercholesterolemia and / or an elevation of lipoprotein(a) can be treated with lipoprotein apheresis (LA) in high-risk patients. Methods We measured serum PCSK9 levels in patients eligible for the extracorporeal treatment: in 40 patients (Cohort I) who were treated with different systems before and after apheresis sessions and in the intervals between sessions. 10 patients (Cohort II) who were eligible but did not start LA yet served as controls. Results Patients' baseline serum PCSK9 levels were elevated relative to healthy volunteers and LA sessions acutely reduced the mean PCSK9 concentrations by 51%. Comparison of the effectiveness of the different LA methods demonstrated the DSA and HELP were more effective than the DALI system. After 24 h PCSK9 levels had returned to baseline compared to 8 days for the LDL-C concentrations to return to its pre-apheresis levels. In Cohort II baseline PCSK9 levels were similar to those in Cohort I. Conclusion The acute reductions of PCSK9 by apheresis may be beneficial with respect to increasing the effectiveness of lipid-lowering drugs and with respect to an anti-atherosclerotic effect. In the future, antagonists to PCSK9 will probably be combined with or possibly replace LA in patients with a very high cardiovascular risk.

Chronic rhinosinusitis (CRS) is a complex inflammatory disease with variable disease manifestation. Though external risk factors are associated with development and/or persistence of CRS, the host mucosal response is also important, as nasal epithelium acts as a physical and immune barrier. Under inflammatory stress, the nasal epithelium can undergo injury, followed by a rapid remodeling response ranging from epithelial hyperplasia, to goblet-cell metaplasia, to denudation, loss of cilia, fibrosis, and basement membrane thickening. Identification of gene expression signatures and molecular pathways in CRS pathogenesis have now begun to contribute significantly to a better understanding of the genetic and molecular alterations underlying CRS development and progression. Genetic studies are especially illuminating when multiple gene variants synergize within a permissive environmental context, and are expected to guide development of more effective therapeutic targets for CRS treatment.

To test the hypothesis that uvulopalatopharyngoplasty (UPPP) improves sleep apnea-related quality of life (measured on the Functional Outcomes of Sleep Questionnaire [FOSQ]) at 3-month follow-up. Secondary objectives were to test (1) the stability of the outcomes at 6 months, (2) the effect on global sleep apnea quality-of-life change, and (3) the effect on sleep apnea symptoms.Multicenter, prospective, longitudinal case series.Diverse university- and community-based otolaryngology practices.The cohort included 68 patients from 17 practices, with a mean ± standard deviation age of 44 ± 12 years and mean apnea-hypopnea index of 35 ± 32 events/hour. All patients underwent UPPP, defined as an open procedure modifying the shape and size of the palate, pharynx, and uvula, with or without tonsillectomy. Baseline data were collected on site before surgery, and outcome data were collected by mail 3 and 6 months after surgery, with follow-up rates of 51% and 50%, respectively.FOSQ scores improved from 14.3 ± 3.4 (scale 5-20, normal ≥17.9) at baseline to 17.2 ± 2.7 at 3 months (mean improvement 2.9; 95% confidence interval, 1.8-4.0; P.001) and 17.5 ± 2.5 at 6 months (mean improvement 3.1; 95% confidence interval, 2.0-4.2; P.001). All quality-of-life and symptom measures improved significantly at 3 and 6 months (all P.05).This prospective, multicenter, university- and community-based study provides evidence that UPPP significantly improves disease-specific quality of life and sleep apnea symptoms in patients with sleep apnea. Validity may be limited by significant loss to follow-up and absence of an unoperated control group.

The culture of tumor cell lines in three-dimensional scaffolds is considered to more closely replicate the in vivo tumor microenvironment than the standard method of two-dimensional cell culture. We hypothesized that our method of encapsulating and maintaining viable and functional pancreatic islets in agarose–agarose macrobeads (diameter 6–8 mm) might provide a novel method for the culture of tumor cell lines. In this report we describe and characterize tumor colonies that form within macrobeads seeded with mouse renal adenocarcinoma cells. Approximately 1% of seeded tumor cells survive in the macrobead and over several months form discrete elliptical colonies appearing as tumor cell niches with increasing metabolic activity in parallel to colony size. The tumor colonies demonstrate ongoing cell turnover as shown by BrdU incorporation and activated caspase-3 and TUNEL staining. Genes upregulated in the tumor colonies of the macrobead are likely adaptations to this novel environment, as well as an amplification of G1/S cell-cycle checkpoints. The data presented, including SCA-1 and Oct4 positivity and the upregulation of stem cell–like genes such as those associated with the Wnt pathway, support the notion that the macrobead selects for a subpopulation of cells with cancer stem cell or cancer progenitor properties. Cancer Res; 71(3); 716–24. ©2011 AACR.

Cancer cells and their associated tumors have long been considered to exhibit unregulated proliferation or growth. However, a substantial body of evidence indicates that tumor growth is subject to both positive and negative regulatory controls. Here, we describe a novel property of tumor growth regulation that is neither species nor tumor-type specific. This property, functionally a type of feedback control, is triggered by the encapsulation of neoplastic cells in a growth-restricting hydrogel composed of an agarose matrix with a second coating of agarose to form 6- to 8-mm diameter macrobeads. In a mouse cell model of renal adenocarcinoma (RENCA cells), this process resulted in selection for a stem cell–like subpopulation which together with at least one other cell subpopulation drove colony formation in the macrobeads. Cells in these colonies produced diffusible substances that markedly inhibited in vitro and in vivo proliferation of epithelial-derived tumor cells outside the macrobeads. RENCA cells in monolayer culture that were exposed to RENCA macrobead-conditioned media exhibited cell-cycle accumulation in S phase due to activation of a G2/M checkpoint. At least 10 proteins with known tumor suppression functions were identified by analysis of RENCA macrobead-conditioned media, the properties of which offer opportunities to further dissect the molecular basis for tumor growth control. More generally, macrobead culture may permit the isolation of cancer stem cells and other cells of the stem cell niche, perhaps providing strategies to define more effective biologically based clinical approaches to treat neoplastic disease. Cancer Res; 71(3); 725–35. ©2011 AACR.

Patients undergoing dialysis treatment have a high incidence of dyslipidemia. Rosuvastatin is a potent statin drug that improves overall lipid profiles in dyslipidemic patients. However, the pharmacokinetics of rosuvastatin has not been studied in patients with end-stage kidney disease undergoing chronic peritoneal dialysis (PD). The goals of this study are to determine the pharmacokinetics and tolerability of a single oral dose of rosuvastatin in patients undergoing continuous ambulatory PD (CAPD). This was a nonrandomized, open-label, 1-week trial. Ten stable PD patients were given a single oral dose of rosuvastatin (10 mg). Serial blood samples were obtained over the next 48 hours, and the patients were followed for 1 week while they underwent CAPD. Rosuvastatin plasma concentration peaked (Cmax) at 3.68 +/- 2.3 ng/ml (geometric mean), 4.5 hours (median; range 2 - 6 hours) after oral dosing. The plasma concentration of rosuvastatin was 0.44 +/- 0.23 ng/ml at 24 hours (C24) and 0.14 +/- 0.07 ng/ml, with levels below the detectable range in 5 of 10 subjects, at 48 hours (C48). The area under the plasma concentration-time from 0 to 48 hours (AUC0-48) was 32.6 +/- 1.6 ng/ml/h. These pharmacokinetic profiles of rosuvastatin in CAPD patients are very similar to those observed in healthy volunteers, but different from patients with Stages 4 - 5 chronic kidney disease. A single oral dose of rosuvastatin was well tolerated in this small number of patients. We conclude that pharmacokinetic profiles of rosuvastatin in patients undergoing CAPD are similar to those observed in healthy volunteers. These findings suggest that a lower dose of rosuvastatin (<

Allergic rhinitis (AR), a chronic inflammatory disease of the upper airway, is one of the most common chronic diseases in the United States and is estimated to affect up to 60 million people. Pediatric Allergies in America is the largest and most comprehensive survey to date of pediatric patients and parents of patients with allergy, as well as health care providers (HCPs), regarding AR in children and its treatment. The goals of the survey were to determine the prevalence of AR in the US pediatric population and to collect information on what effect the condition has on patients in terms of symptom burden, quality of life, productivity, disease management, and pharmacologic treatment. This national survey screened 35,757 households to identify 500 children with HCP-diagnosed nasal allergies and 504 children without nasal allergies who were between the ages of 4 and 17 years. Parents of young children, as well as children 10 to 17 years of age, were questioned about the condition and its treatment. In parallel, 501 HCPs were interviewed. This survey has captured previously unavailable data on the prevalence of nasal allergies and their most common and most bothersome symptoms, on the effect of nasal allergies on the quality of life of children, and on medication use, including both over-the-counter and prescription medications, and has identified factors affecting satisfaction with treatment. The Pediatric Allergies in America survey also identifies distinct areas for improvement in the management of AR in children. In fact, based on the results of this survey, it appears that HCPs overestimate patients' and parents' satisfaction with disease management and the benefit of medications used for the treatment of nasal allergies in children. Findings from this national survey have identified important challenges to the management of AR, suggesting that its burden on children in the United States has been significantly underestimated.

Untreated pediatric patients with homozygous familial hypercholesterolemia usually have myocardial infarctions, heart failure, or death by the teenage years. Low-density lipoprotein (LDL) apheresis effectively lowers LDL cholesterol in the short term, but there is little published information on the long-term safety and efficacy of this treatment in children. An analysis was performed of a registry of all 29 patients who began LDL apheresis before 18 years of age at 15 sites during the 11 years since approval by the United States Food and Drug Administration. A chart review of 9 patients treated at The Rogosin Institute was also performed to obtain additional details about lipid lowering, adverse events, and cardiovascular status. Of the 29 patients, 20 are currently treated, with a mean age at the start of treatment of 9 +/- 4 years (range 3 to 15) and a mean treatment duration of 6 +/- 4 years (range 2 to 21). The baseline LDL cholesterol (521 +/- 126 mg/dl) is acutely lowered by 75% and chronically lowered by 48% with biweekly sessions. Systemic adverse events have been uncommon. Atherosclerotic disease of the coronary arteries and/or aorta or aortic valve was evident by angiography and/or echocardiography in 12 patients (60%) at baseline and progressed to more severe, symptomatic disease in 6 (30%). In conclusion, LDL apheresis is well tolerated for decades by even very young pediatric patients with homozygous familial hypercholesterolemia. It effectively lowers LDL cholesterol, but target LDL levels are not achieved, and some patients will show progression of cardiovascular disease.

Homozygous familial hypercholesterolemia (HoFH) is a rare, inherited, life-threatening, metabolic disorder of low-density lipoprotein (LDL) receptor function characterized by elevated serum LDL cholesterol (LDL-C) and rapidly progressive atherosclerotic cardiovascular disease (ACVD). Since LDL receptors are predominantly found on hepatocytes, orthotopic liver transplantation (OLT) has emerged as a viable intervention for HoFH because LDL receptor activity is restored. This study assessed the effects of OLT on ACVD and ACVD risk factors in pediatric patients with HoFH. We analyzed lipids, lipoproteins, body mass index, glucose, blood pressure, and cardiovascular imaging in 8 pediatric patients who underwent OLT for HoFH. Total serum cholesterol, LDL-C, lipoprotein (a), and apolipoprotein B/apolipoprotein A1 ratio decreased to normal values in all subjects (p values0.001) at 1 month after OLT and were maintained for the length of follow-up (2 to 6 years). There were few complications related to surgery or immunosuppressive therapy. Two patients developed mild hypertension. In the first 4 subjects monitored for 4 to 6 years after OLT, coronary artery disease did not develop or progress except in 1 minor artery in 1 subject and actually regressed in 2 subjects with50% stenosis. However, aortic valve stenosis progressed in 2 of 4 subjects. In conclusion, OLT is an effective therapeutic option for patients with HoFH with coronary artery disease and persistently elevated serum LDL-C despite maximum medical therapy. Aortic valvular disease may progress. Long-term data are needed to evaluate the true risk-benefit ratio of this surgical approach.

Monocyte chemoattractant protein-1 (MCP-1) is essential in atherogenesis. Oxidized lipids regulate MCP-1 expression and release from mononuclear cells. In this study we investigated (1) whether statin therapy reduces lipopolysaccharide (LPS)–stimulated MCP-1 production in human whole-blood samples and (2) the relationships between in vitro low-density lipoprotein (LDL) oxidation and MCP-1 production. Fasting blood samples were obtained from 55 healthy nonsmoking adults with moderate hypercholesterolemia who were participating in a randomized double-blind 8-week trial comparing the effects of statin therapy with those of placebo on cytokine production. Samples were analyzed for resistance to copper-mediated LDL oxidation (lag time in minutes), as well as MCP-1– and interleukin-8 (IL-8)–stimulated production. Statin therapy reduced MCP-1 production (mean ± SD) −161 ± 399 pg/mL/mm 3 white cells) compared with 267 ± 985 pg/mL/mm 3 in the placebo group, but changes were not different between active and placebo groups ( P = .13). Statin therapy also increased lag times (median [interquartile range]; 20.5 [7.0–51.2] minutes vs −17.0 [−5.3–16.5] minutes; P = .067 for group difference). Inhibition of MCP-1 production correlated with prolongation of lag time ( r = .46, P = .0056) in statin-treated subjects. Statin therapy reduced MCP-1 production in the whole blood of human subjects and these changes were correlated with improvement in LDL oxidative resistance.

Objective This study was undertaken to demonstrate the safety and efficacy of in vitro, radioallergosorbent test (RAST)-based inhalant allergen immunotherapy. Study design and setting Prospective 22 year single site clinical study, with outcome evaluations of 480 perennial allergic rhinitis patients, including 96 with concomitant asthma. Results Rhinitis symptom control after 2 years of immunotherapy was excellent in 32.5% of patients, good in 45.6%, and fair in 14.2%. There was no improvement in 7.7%. For patients with asthma, 81% had good or excellent pulmonary symptom improvement, and no patient failed to improve. No severe reactions occurred, but there were 5 limited systemic reactions, or 0.008% of injections, during a 2.5-year mean immunotherapy treatment course. Conclusion RAST-based immunotherapy is safe and effective for patients with perennial allergic rhinitis, with or without concomitant asthma. Significance This is the first large, multiyear study of safety and efficacy of RAST-based immunotherapy for treatment of perennial allergic rhinitis and asthma. EBM rating: C.

PURPOSE OF REVIEW Nasal obstruction, the cardinal symptom of persistent (perennial) allergic rhinitis, is one of the most common symptoms encountered in primary care and in specialist clinics. It is difficult to quantify by clinical examination, and, hence, objective assessment of the nasal airway is critical to rhinologic research. Nasal obstruction in persistent allergic rhinitis must be treated the year round, and therefore treatment choices, costs, and compliance all become important public health issues. RECENT FINDINGS Many inflammatory and neurogenic mediators released during allergic reactions are able to cause plasma exudation and vasodilatation, with resultant edema and swelling of the nasal mucosa. Recently, technological advancements have made it possible to qualitatively and quantitatively study the nasal airway, providing greater insights into the understanding of physiological fluctuation and pathophysiological manifestations of nasal patency. From recent international guidelines, the management of allergic rhinitis includes combining treatments of the upper and lower airways, by using patient education, allergen avoidance, pharmacological treatment, and specific immunotherapy. Surgery may be needed as an adjunctive intervention. Multiple methods have been introduced to treat turbinate hypertrophy. However, preservation of adequate nasal mucosal function is important, together with long-term results. SUMMARY It is important that consensus recommendations for the management of allergic rhinitis be designed and implemented by all levels of medical specialists in order to improve treatment outcomes.

Decreased concentrations of total cholesterol, lipoproteins, and lipoprotein cholesterols occur early in the course of critical illness. Low cholesterol concentrations correlate with high concentrations of cytokines such as interleukin (IL)-6 and IL-10, and may be due to decreased synthesis or increased catabolism of cholesterol. Low cholesterol concentrations have been associated clinically with several adverse outcomes, including the development of nosocomial infections. The study was performed to test the hypothesis that a low cholesterol concentration predicts mortality and secondarily predicts the development of organ dysfunction in critical surgical illness.A prospective study was undertaken of 215 patients admitted to a university surgical ICU with systemic inflammatory response syndrome (SIRS). Serial blood samples were collected within 24 h of admission, as well as on the morning of days 2, 4, and 7 of the ICU stay for as long as the patients were in the ICU. Demographic data and predetermined outcomes were noted.One hundred nine patients had at least two samples drawn and form the population for analysis. Sixty-two of the patients had three samples obtained, whereas 42 patients had four samples obtained. By univariate analysis, non-survivors were more severely ill on admission (APACHE III), more likely to have been admitted to the ICU as an emergency, more likely to develop a nosocomial infection, and more likely to develop severe organ dysfunction (MODS) (all, p0.05). Death was associated on day 1 with increased concentrations of sIL2R, IL-6, IL-10, and sTNFR-p75 (all, p0.01), but there were initially no differences in serum lipid concentrations. However, by day 2, concentrations of IL-6, IL-10, and cholesterol had decreased significantly (all, p0.05) from day 1 in non-survivors but not in survivors; the difference in serum cholesterol concentration persisted to day 7 (p0.05). Persistently elevated concentrations of IL-6 and IL-10 were observed in patients who developed severe MODS. By logistic regression, increased APACHE III score, development of a nosocomial infection, and decreased cholesterol concentration were independently associated with mortality.Decreased serum cholesterol concentration is an independent predictor of mortality in critically ill surgical patients. Repletion of serum lipids is a feasible therapeutic approach for the management of critical illness.

Testing for food and chemical sensitivities usually becomes necessary as part of the evaluation of otolaryngology patients who have chronic illness. The more complex the patient, and the more recalcitrant the problem is to treatment, the more likely it is that allergies, and especially food or chemical sensitivities, are involved in the pathogenesis of the illness. Failure to consider all major allergen contacts, including foods and chemicals, can lead to inadequate therapy. Similarly, failure to understand total allergic and oxidant load and the effects of chemical toxicity can lead to inappropriate or ineffective treatment. Clinically, food allergies occur in two different types: immediate, anaphylactic, fixed reactions and delayed, chronic, cyclic reactions. Different test methods have been developed for the two types. Fixed food allergies can be safely and efficiently detected by in vitro specific IgE or histamine release tests. Cyclic food allergies are best detected by either oral food challenges or by the IPDFT test. Choosing the best test for a particular patient requires a clear understanding of the two food allergy types and how their clinical presentations differ. Other tests for food allergies are compared and contrasted with these primary tests. Chemical sensitivity also occurs in two different clinical types: allergic, and toxic. True allergy to chemical haptens, either type I, IgE-mediated, or type IV, delayed hypersensitivity, occurs with significant frequency but is often unsuspected. Chemical toxicity can be caused by the aftereffects of an acute exposure or as a result of chronic, low-level exposure, but is even more frequently unsuspected and will not be diagnosed without a high index of suspicion. Both types of chemical sensitivity need to be addressed in any patients who have either a high allergen or chemical exposure load [105]. Either in vitro or in vivo tests can be used for chemical allergy detection; the advantages of each are outlined. Chemical toxicity screening tests are available and useful but do not detect all possible toxicants. Definitive toxic chemical tests usually require specialized laboratory facilities and expert consultation, for which possible sources are specified. The most important point in testing for food or chemical sensitivity is to be aware that food or chemical sensitivity can be contributing to a specific patient's clinical problems. Only then can appropriate investigations be undertaken to understand and then, perhaps, to intervene successfully in that illness.

Endotoxemia is associated with rapid and marked declines in serum levels of LDL and HDL by unknown mechanisms. Six normal volunteers received a single, small intravenous (iv) dose of endotoxin (Escherichia coli 0113, 2 ng/kg) or saline in a random order, cross-over design. After endotoxin treatment, volunteers had mild, transient flu-like symptoms and markedly increased serum levels of tumor necrosis factor and its soluble receptors, interleukin-6, cortisol, serum amyloid A, and C-reactive protein. Triglyceride (TG), VLDL-TG, and nonesterified fatty acid increased (peak at 3–4 h), then TG declined (nadir at 9 h), and then cholesterol, LDL cholesterol, apolipoprotein B (apoB), and phospholipid declined (nadirs at 12–24 h). HDL cholesterol and apoA-I levels were not affected, but half of the decrease in phospholipid was HDL phospholipid. Lipopolysaccharide binding protein (LBP) rose 3-fold (peak at 12 h), with smaller and later decreases in the activities of phospholipid transfer protein and cholesteryl ester transfer protein. In conclusion, a decline in LDL was rapidly induced in normal volunteers with a single iv dose of endotoxin. The selective loss of phospholipid from HDL may have been mediated by LBP and, after more intense or prolonged inflammation, could result in increased HDL clearance and reduced HDL levels.

BACKGROUND:Lipids and lipoproteins have been shown to bind and neutralize endotoxin and to improve outcomes in animal models of sepsis.OBJECTIVE:To provide safety and pharmacokinetic data for a protein-free, phospholipid-rich emulsion developed as an agent to neutralize endotoxin, and to study the changes in lipids and lipoproteins following emulsion administration.METHODS:Thirty healthy male volunteers (aged 18–45 y) were given an emulsion containing 92.5% soy phospholipid, 7.5% soy triglyceride, and 18 mM sodium cholate using a double-blind, placebo-controlled crossover protocol. Emulsion at 3 escalating doses (75, 150, 300 mg/kg) based on phospholipid content was administered by intravenous infusion over 2 hours in the low- and mid-dose groups and 6 hours in the high-dose group.RESULTS:All subjects completed the protocol without significant toxicities. A slight dose-dependent increase in indirect bilirubin at the 24-hour time point was observed in the emulsion treatment period, with a maximum difference between placebo and emulsion of 0.9 mg/dL. Mean ± SD peak phospholipid levels were 316 ± 30, 533 ± 53, and 709 ± 86 mg/dL, and phospholipid half-lives were 5.4 ± 0.6, 5.4 ± 0.5, and 8.0 ± 0.8 hours for the low, mid, and high doses, respectively. Increases in total cholesterol, low-density lipoprotein cholesterol and apolipoprotein A-I and B levels were observed. High-density lipoprotein cholesterol decreased immediately following emulsion infusion, but rebounded to above placebo levels by 24 hours.CONCLUSIONS:A unique phospholipid-rich emulsion was shown to have a favorable safety profile and to expand the blood lipid and lipoprotein pool without the use of human-derived blood products. Lipid levels expected to protect against the physiologic effects of bacterial endotoxin were achieved.

To determine the relationship of hypolipidemia to cytokine concentrations and clinical outcomes in critically ill surgical patients.Consecutive, prospective case series.Surgical intensive care unit of an urban university hospital.Subjects were 111 patients with a variety of critical illnesses, for whom serum lipid, lipoprotein, and cytokine concentrations were determined within 24 hrs of admission to a surgical intensive care unit. Controls were 32 healthy men and women for whom serum lipid, lipoprotein, and cytokine concentrations were determined.Blood samples were drawn on admission to the intensive care unit. Predetermined clinical outcomes including death, infection subsequent to intensive care unit admission, length of intensive care unit stay, and magnitude of organ dysfunction were monitored prospectively.Measurements included total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoproteins A-I and B, phospholipid, triglyceride, interleukin-6, interleukin-10, soluble interleukin-2 receptor, tumor necrosis factor-alpha, and soluble tumor necrosis factor receptors p55 and p75. Mean serum lipid concentrations were extremely low: total cholesterol, 127 +/- 52 mg/dL; low-density lipoprotein cholesterol, 75 +/- 41 mg/dL; high-density lipoprotein cholesterol, 29 +/- 15 mg/dL. Total, low-density lipoprotein, and high-density lipoprotein cholesterol concentrations and apolipoprotein concentrations inversely correlated with interleukin-6, soluble interleukin-2 receptor, and interleukin-10 concentrations, whereas the triglyceride concentration correlated positively with tumor necrosis factor soluble receptors p55 and p75. Clinical outcomes were related to whether the admission cholesterol concentration was above (n = 56) or below (n = 55) the median concentration of 120 mg/dL. Each of the clinical end points occurred between 1.9- and 3.5-fold more frequently in the very low cholesterol (120 mg/dL) group. Nine patients (8%) died during the hospitalization. Seven of the nine patients who died had total cholesterol concentrations below the median concentration of 120 mg/dL.Low cholesterol and lipoprotein concentrations found in critically ill surgical patients correlate with interleukin-6, soluble interleukin-2 receptor, and interleukin-10 concentrations and predict clinical outcomes.

Treatment to low-density lipoprotein (LDL) cholesterol targets has become a focus in the management of patients with coronary heart disease (CHD). Many patients with familial hypercholesterolemia (FH) are unable to reach targets because of drug intolerance or extremely high baseline LDL cholesterol levels. Consequently, LDL apheresis has become a useful modality for the treatment of patients with severe hypercholesterolemia. Commonly used LDL apheresis systems utilize immunoadsorption columns, dextran sulfate cellulose columns, or heparin precipitation. A new and simpler treatment modality is emerging which uses whole blood compatible columns. All systems require systemic anticoagulation, extracorporeal processing of blood, and venous vascular access. Acute LDL lowering is 70% to 80% and time-averaged LDL lowering is 40% to 50%. Lipoprotein(a) is also substantially lowered. Clinical efficacy has been shown in several studies. Mechanisms for clinical improvement in addition to regression of atherosclerotic plaque have been suggested by recent research.

Vitamin D (vitD3) deficiency occurs frequently and has profound effects on health, especially asthma. This article examines how current knowledge of vitD3 actions and the worldwide distribution of vitD3 deficiency influences everyday clinical allergy practice. Within the limits of current knowledge, the article concisely explains the molecular nature of vitD3 actions, reviews key vitD3 research as it applies to clinical care, answers questions about the potential clinical impact of low vitD3 levels, and discusses use and safety of vitD3 supplements.

The use of LDL-apheresis to treat patients with severe hypercholesterolemia has gained wider clinical acceptance during the past 2-3 years, particularly in patients with coronary artery disease. Systems utilizing immunoadsorption columns, dextran sulfate cellulose columns and heparin precipitation have been most commonly employed. New or improved technologies include whole-blood compatible columns, double-filtration plasmapheresis and lipoprotein (a)-apheresis. The mechanisms for clinical improvement extend beyond simple regression of atherosclerotic plaque.

Lipoprotein(a) [Lp(a)] is a genetically determined risk factor for vascular disease and a potential link between coagulation, lipoproteins, and the development of atherosclerosis. Its role in the vascular complications of patients with chronic renal disease is unclear. We review methodologic issues involved in measuring Lp(a), particularly as they relate to studies of patients with chronic renal disease. The accurate measurement of Lp(a) is difficult because all the commercially available assays are sensitive to apolipoprotein(a) isoform size, Lp(a) behaves like an acute phase reactant, and levels vary markedly among ethnic groups. The results of 12 studies that included data on median Lp(a) levels in controls and patients receiving renal replacement therapy were analyzed. Although there was variation among studies, most found elevated levels of Lp(a) in patients receiving hemodialysis (range of medians, 9.0 to 38.4 mg/dL) compared with controls (range of medians, 4.7 to 19.7 mg/dL). With the exception of one study, Lp(a) levels also were elevated in patients receiving continuous ambulatory peritoneal dialysis compared with controls and patients receiving hemodialysis. In one study, an elevated Lp(a) level in patients receiving hemodialysis correlated with subsequent development of vascular events. A separate study associated the occurrence of vascular access occlusion with Lp(a) level. Following renal transplantation, Lp(a) levels decreased in all four studies, which included data before and after transplantation. Although variability in results were seen, Lp(a) levels appear to be elevated in patients receiving renal replacement therapy. Renal transplantation at least partially reverses this effect. The variability in results is probably related to methodologic difficulties in measuring Lp(a) and failure to segregate ethnic groups in study design and analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Statins are highly effective drugs prescribed to millions of people to lower LDL-cholesterol and decrease cardiovascular risk. The benefits of statin therapy seen in randomized clinical trials will only be replicated in real-life if patients adhere to the prescribed treatment regimen. But, about half of patients discontinue statin therapy within the first year, and adherence decreases with time. Patient, physician and healthcare system-related factors play a role in this problem. Recent studies have focused more on the patients’ perspectives on non-adherence. Adverse events are cited as the most common cause of statin discontinuation; thus, the healthcare provider must be willing to ally and dialogue with patients to address concerns and assess the risks and benefits of continued statin therapy.

We evaluated, by CFD simulation, effects of accessory ostium (AO) on maxillary sinus ventilation. A three-dimensional nasal model was constructed from an adult CT scan with two left maxillary AOs (sinus I) and one right AO (sinus II), then compared to an identical control model with all AOs sealed (sinuses III and IV). Transient simulations of quiet inspiration and expiration at 15 L/min, and nasal blow at 48 L/min, were calculated for both models using low-Reynolds-number turbulent analysis. At low flows, ventilation rates in sinuses with AOs (I ≈ 0.46 L/min, II ≈ 0.54 L/min), were both more than a magnitude higher than sinuses without AOs (II I ≈ 0.019 L/min, IV ≈ 0.020 L/min). Absence of AO almost completely prevented sinus ventilation. Increased ventilation of sinuses with AOs is complex. Under high flow conditions mimicking nose blowing, in sinuses II, III, and IV, the sinus flow rate increased. In contrast, the airflow direction through sinus I reversed between inspiration and expiration, while it remained almost constant throughout the respiration cycle in sinus II. CFD simulation demonstrated that AOs markedly increase maxillary sinus airflow rates and alter sinus air circulation patterns. Whether these airflow changes impact maxillary sinus physiology or pathophysiology is unknown.

Intradermal skin testing is a useful allergy diagnostic tool. Although considered safe when properly performed, systemic reactions have been reported. This is the first large, prospective study to record and evaluate all systemic reactions from intradermal skin testing (IDT) to inhalant or food antigens.A 24-month prospective study by 40 physician practices, recording all IDT tests, including reactions, symptoms, severity, time after injection, and reaction treatments.Eighty systemic reactions (22 major) occurred among 20,530 patients (878,583 wheals). Nine had epinephrine treatment, 4 were observed in an emergency department, and there were no hospitalizations or fatalities. The overall systemic reaction risk was 0.009%. The risk of having a major reaction was 0.003%, or 1 reaction per 933 patients.Intradermal skin tests for inhalants or foods, when performed with appropriate precautions, have a safety profile comparable to skin prick tests.

Low-density lipoprotein (LDL) apheresis offers an additional approach to lipid lowering in patients with severe hypercholesterolemia who fail to respond adequately to diet and drug therapy. Well-defined criteria for patient selection have yet to be established for LDL apheresis. This study proposes guidelines based on whether coronary artery disease (CAD) is present and on the degree of LDL cholesterol elevation after treatment with diet and maximal drug therapy. It is reasonable to consider LDL apheresis therapy for: (1) patients with CAD and LDL cholesterol levels >190 mg/dl; (2) patients without CAD, but at high risk for disease due to an LDL cholesterol level >250 mg/dl, a first-degree relative with premature CAD, and the presence of ≥1 additional risk factor. In addition, LDL apheresis is recommended for the management of all patients with homozygous familial hypercholesterolemia due to the very high risk of CAD and the poor response to usual lipid-lowering treatments.

LDL-apheresis is an extracorporeal plasma-perfusion method that selectively removes apolipoprotein B-containing lipoproteins from the blood. It is indicated for patients with homozygous and drug-resistant heterozygous familial hypercholesterolemia. Clinical and angiographic regression of coronary artery disease has been demonstrated in patients treated with cholesterol-lowering programs that include LDL-apheresis.

Epithelial remodeling is a part of our natural defense mechanisms, and includes migration, proliferation, and differentiation of epithelial cells, as well as the interactions between epithelial and stromal cells. It is not yet possible to distinguish between cause and effect during epithelium remodeling, and are there no clear roles for the many factors involved in respiratory infectious and inflammatory diseases due to a lack of critical information about epithelial cell responses. Most reported data are from lower airway studies or animal models. Therefore, research based on human nasal epithelial stem/progenitor cells can illuminate the pathophysiology of nasal airway disease from a different, more specific perspective. In this review, we discuss epithelial stem/progenitor cell research throughout the airway, with special attention to phenotypes and characterization of these cells from the nasal airway. Recently, we have isolated and cultured P63-positive human epithelial stem/progenitor cells from turbinate biopsies of healthy volunteers and from inflamed mucosa of patients with chronic rhinosinusitis with and without nasal polyposis. These cells propagate in serum-free, growth factor-supplemented, Dulbecco's modified Eagle's medium/F12 media, on either human fibroblast or 3T3 feeder layers. Self-renewal, proliferation, and differentiation potential at an air-liquid interface are being investigated to understand the molecular pathways underlying nasal inflammation. This in vitro culture system for nasal epithelial regeneration will allow molecular studies of human nasal epithelial cell interactions, differentiation, and repair, as well as responses to both environmental agents and to potential anti-inflammatory treatments.

The allergic march is a progression of atopic disease from eczema to asthma, and then to allergic rhinoconjunctivitis. It appears to be caused by a regional allergic response with breakdown of the local epithelial barrier that initiates systemic allergic inflammation. Genetic and environmental factors predispose to developing the allergic march. There are data to support 4 possible interventions to prevent the allergic march from progressing to asthma: (1) supplements of dietary probiotics, (2) exclusive breast feeding during the first few months of life, or, alternatively (3) use of extensively hydrolyzed infant formulas, (4) treatment with inhalant allergen immunotherapy by either subcutaneous or sublingual methods.

Patch testing has rapidly become an important clinical allergy tool, but is underutilized in the evaluation of complex patients, especially when these patients have skin disorders and respiratory allergies, food allergies, or eosinophilic enteritis. Learning when and how to use patch tests thus adds to any practitioner's diagnostic abilities.This review discusses selected studies from the past year, grouped into immunology, pediatric testing, contact allergy, food allergy, and drug allergy.Patch tests can detect a wide range of sensitivities to inorganic and organic chemicals, drugs, biologic molecules, inhalants acting as contactants, food allergens, allergens that have not been commercially extracted, and solid allergens. Because patch tests detect the full range of immunologic reactions, Gell and Coombs type I to IV, they may be uniquely reactive when other allergy tests are negative. Because of the large number of published studies that utilize patch testing, clinicians often can use a literature search of prior studies of similar problems, or for particular allergens, to choose technical details that make successful patch testing more likely.

ADAMTS13 mediated thrombotic thrombocytopenic purpura (TTP) is an immunological disease that is very difficult to treat. Plasma exchange, with plasma replacement and steroids have been the first line of treatment for this condition. Ten to 20% of the patients either have no response or a partial response to the treatment. Refractory TTP has been treated in few case reports with anti-CD20 agents, intravenous gamma globulin, vincristine and splenectomy. We report two cases of refractory TTP that responded to multimodality immunosuppressive therapy that included splenectomy, intravenous gamma globulin, and cyclosporine after numerous plasma exchange treatments, steroids, rituximab and vincristine had failed to induce remission. Combining drugs that target T and B lymphocytes is a standard in organ transplantation and deserves more consideration in the treatment of severe and refractory autoimmune diseases such as TTP.

Asthma is suspected from a history of key symptoms, including cough, wheezing, dyspnea, chest tightness, and increased mucus production. A positive family or personal history of atopic diseases and diseases that are comorbid with asthma, such as allergic rhinitis and rhinosinusitis, is also important. The differential diagnosis of asthma is broad and includes potentially life-threatening diseases. Pediatric asthma and psychiatric mimics require special attention to prevent misdiagnosis. Differentiating asthma from these other disease states by history alone is not always possible. Because accurate diagnosis is critical to successful treatment, objective testing by spirometry and methacholine challenge should be employed.

Comparison of open food challenge (OFC) with double-blind placebo-controlled food challenge (DBPCFC).Prospective sequential randomized challenges.Twenty adults with chronic allergy symptoms and at least 1 positive intradermal food wheal response recorded symptoms during DBPCFC and OFC provoked using organic foods, normal portions, and normal food preparation. Acoustic Rhinometry and biochemical tests were done during DBPCFC.All patients reacted to at least 1 food and to all challenges with the same food, with multiorgan symptoms in the nose, nervous system, throat, and lung. There was a correlation in the type and severity of symptoms (P = 0.015) for OFC and DBPCFC, and both were significantly (P0.01) more severe than placebo. Compared with DBPCFC, OFC sensitivity was 66%, and positive predictive value was 89%.This is the first study showing both concordance of OFC and DBPCFC and also that intradermal tests can identify reactive foods that can be verified by DBPCFC. Because most tests for IgE-mediated food allergy were negative, observed reactions were probably non-IgE mediated.

BACKGROUND An approach to endotoxin (lipopolysaccharide [LPS]) blockade makes use of the ability of lipoproteins, via surface phospholipids, to bind and neutralize LPS. The aim of the present study was to determine whether the intravenous administration of a protein-free, phospholipid-rich emulsion is an effective method for neutralizing the effects of LPS in healthy persons. METHODS This was a double-blind, placebo-controlled study in 20 volunteers. Volunteers received Escherichia coli endotoxin (2 ng/kg) intravenously 2 h into a 6-h infusion of either emulsion (210 mg/kg) or placebo (Intralipid diluted 1 : 64). RESULTS The volunteers who received emulsion had a lower mean clinical score (P

The effect of statins on bone mass and fracture rates is uncertain. Therefore, we investigated whether statin therapy acutely altered bone turnover as measured by changes in bone serum markers (bone-specific alkaline phosphatase, osteocalcin, and type I collagen N-telopeptide cross-links). Fasting blood samples were obtained from 55 (M/F 39/16) healthy nonsmoking adults (mean +/- standard deviation: age, 50.4+/-7.5 years; body mass index, 27.8+/-4.9 kg/m(2)) with low-density lipoprotein cholesterol concentrations between 3.38-4.90 mmol/l. Subjects were randomized to four possible 8-week treatment regimens: placebo (n =14), pravastatin 40 mg/daily (n =12), simvastatin 20 mg/daily (n =14) or simvastatin 80 mg/daily (n =15). High-dose simvastatin (80 mg/daily) produced a significant reduction in bone-specific alkaline phosphatase as compared with other treatment regimens (p =0.009). However, there were no changes in urinary N-telopeptide cross-links, a sensitive marker of bone resorption. Short-term use of high-dose simvastatin lowers the level of the serum bone marker bone-specific alkaline phosphatase, which suggests the possibility of reduced bone turnover.

There is currently great interest in developing improved methods of immunotherapy and new techniques of immune system manipulation to ameliorate allergic diseases. This article reviews current research trends in the immunologic treatment of allergy, including the use of chemically modified allergens, nonparenteral allergen exposure, sustained-release allergen delivery, anti-immunoglobulin E antibodies, γ-globulin, immune complexes, cytokines, and T-cell – tolerogenic peptides. (OTOLARYNGOL HEAD NECK SURG 1995;113:603-5.)

Adipose tissue expression of tumor necrosis factor-alpha (TNF-α) has been implicated in the pathogenesis of obesity-linked insulin resistance and the dyslipoproteinemia of insulin resistance. This study has two aims: (1) to compare select inflammatory mediators in non-smoking, normoglycemic male subjects with and without the atherogenic dyslipoproteinemia (ADL), and (2) to determine the effects of statin therapy on select inflammatory mediators. ADL subjects had higher levels of insulin (16.7 ± 7.5 versus 11.6 ± 5.9μIU/mL, P = 0.008), soluble TNF receptor superfamily 1B (sTNFRSF1B) (3.3 ± 0.7 versus 2.7 ± 0.5ng/mL, P = 0.005), and interleukin-6 (IL-6) (2.6 ± 2.2 versus 1.3 ± 1.8pg/mL, P = 0.006) as compared to those of the non-ADL subjects. After adjustment for age, sTNFRSF1B ( P = 0.003) was more predictive of ADL than high-sensitivity C-reactive protein (hs-CRP) ( P = 0.047). Statin therapy did not change sTNFRSF1B, TNF-α, IL-6, hs-CRP, whereas soluble TNF receptor superfamily 1A (sTNFRSF1A) increased slightly ( P = 0.048). A high level of sTNFRSF1B is a strong marker of the pro-inflammatory state in this sample of male ADL subjects.

The goal of this study was to determine the relationship among lipid concentrations, cytokine concentrations, and clinical outcomes of burn patients. Twenty-eight patients admitted within 24 hours of burn injury, segregated based on burn size, had blood samples drawn 24 and 48 hours after burn injury and then weekly for 3 weeks. Measurements included total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, interleukin (IL)-6, soluble IL-2 receptor, and soluble necrosis factor p55 and p75 receptors. Infection, length of stay (LOS), and survival were monitored. Cholesterol and lipoprotein concentrations decreased by at least 40% in patients with burns >20% total body surface area and inversely correlated with IL-6. Lower cholesterol and higher IL-6 values correlated with higher infection rates and longer LOS. IL-6 was the strongest predictor for LOS. In conclusion, outcomes after burn injury are related to low cholesterol and elevated IL-6 levels.

Through the efforts of Edward H. Ahrens, LDL apheresis became available for the treatment of patients, often with familial hypercholesterolemia, who have no alternative therapy for severely elevated LDL cholesterol levels. In the U.S., the FDA has approved this treatment for individuals on maximum diet and drugs with an LDL cholesterol greater than 300 mg/dL or greater than 200 mg/dL with coronary artery disease. Unlike plasmapheresis, apolipoprotein B-containing lipoproteins (LDL, Lp(a), and VLDL) are selectively removed by heparin precipitation or columns containing dextran sulfate cellulose or antibodies to apolipoprotein B. The acute lowering of LDL-cholesterol by a typical 2 - 3 h treatment is up to 80%, and the time-averaged lowering in the 1 to 2 week interval between treatments is up to 50%, with very few side effects. The lowering of LDL-cholesterol and other cardioprotective effects of LDL apheresis have reduced chest pain, prevented new disability and prolonged life. Whole blood compatible columns in development offer the possibility of simpler and less expensive treatments.

We sought to assess skin whealing with glycerin-containing control injections for intradermal skin tests.Observational.Wheal sizes were measured at 0, 10, and 15 minutes after intradermal injection of 0.01 and 0.02 mL of phenolated normal saline and 0.5% and 5% concentrations of glycerin in the same quantity of phenolated saline.Intradermal injection of 0.01 mL of phenolated saline produced an average 4.9-mm wheal, which expanded to 5.2 mm at 10 minutes and to 6.0 mm at 15 minutes. Intradermal injection of 0.02 mL of phenolated saline produced a 6.4-mm wheal, which expanded to 7.0 mm at 10 minutes and 8.0 mm at 15 minutes. The addition of glycerin produced proportionally larger wheals.Because glycerin increases whealing beyond that with phenolated saline, skin tests containing glycerin must be compared with glycerin-containing negative controls. Intradermal skin tests that fail to compare findings in this manner contain an inherent methodologic flaw and are uninterpretable.

During a 1-year period, 27 otolaryngic allergy practices recorded all systemic reactions to immunotherapy resulting from 635,600 patient visits and 1,144,000 injections. Sixty percent of injections were given at home. Major systemic reactions were observed after 0. 005% of injections. There were no hospitalizations or deaths. Eighty-seven percent of major reactions began within 20 minutes of injection. Frequently observed risk factors for major reactions were buildup phase of immunotherapy, active asthma, and first injection from a treatment vial. Home and office injections had similar rates of total systemic reactions, but home-based immunotherapy had far fewer major reactions. Home-based immunotherapy was found to be safe. The methods and precautions used to treat patients with this degree of safety are specified and discussed.

The United States Liposorber Study was a 22 week randomized controlled study of low-density lipoprotein (LDL) apheresis with an optional follow-up phase. The procedure was found to acutely lower LDL cholesterol by up to 81%, have good tolerability, and produce a reduction in the frequency of cardiovascular events. Studies outside the United States have found therapy with LDL apheresis to be associated with a favorable clinical outcome including improved myocardial perfusion, but variable regression of coronary artery disease (CAD). Improvement in blood viscosity and endothelial function may help explain the symptomatic benefits observed with relatively small changes in angiography. Based upon favorable clinical experience, LDL apheresis using dextran sulfate cellulose columns has recently received approval for commercialization in the United States in patients with inadequate responses to diet and drug therapy and LDL levels > or = 200 mg with CAD present or LDL levels > or = 300 mg/dl without CAD.

Objectives To determine the prevalence and clinical significance of hypolipidemia found in critically ill patients, and whether the addition of a reconstituted lipoprotein preparation could inhibit the generation of tumor necrosis factor-alpha (TNF-alpha) in acute-phase blood taken from these patients. Setting Surgical intensive care unit (ICU) of a large urban university hospital. Design Prospective case series. Patients A total of 32 patients with a variety of critical illnesses had lipid and lipoprotein concentrations determined. Six patients and six age- and gender-matched control subjects had whole blood in vitro studies of the effect of lipoprotein on lipopolysaccharide mediated TNF-alpha production. Interventions Blood samples were drawn on admission to the ICU and over a subsequent 8-day period. Measurements and Main Results Mean serum lipid and lipoprotein values obtained from patients within 24 hrs of transfer to the surgical ICU were extremely low: mean total cholesterol was 117 mg/dL (3.03 mmol/L), low-density lipoprotein cholesterol 71 mg/dL (1.84 mmol/L), and high-density lipoprotein cholesterol 25 mg/dL (0.65 mmol/L). Only the mean triglyceride concentration of 105 mg/dL (1.19 mmol/L), and the mean lipoprotein(a) concentration of 25 mg/dL (0.25 g/L) were within the normal range. During the first 8 days following surgical ICU admission, there were trends toward increasing lipid and lipoprotein concentrations that were significant for triglycerides and apolipoprotein B. Survival did not correlate with the lipid or lipoprotein concentrations, but patients with infections had significantly lower (p equals .008) high-density lipoprotein cholesterol concentrations compared with noninfected patients. Lipopolysaccharide-stimulated production of TNF-alpha in patient and control blood samples was completely suppressed by the addition of 2 mg/mL of a reconstituted high-density lipoprotein preparation. Conclusions Patients who are critically ill from a variety of causes have extremely low cholesterol and lipoprotein concentrations. Correction of the hypolipidemia by a reconstituted highdensity lipoprotein preparation offers a new strategy for the prevention and treatment of endotoxemia.

The effect of lipid lowering on hard exudates was determined in six consecutive patients with insulin-dependent diabetes mellitus. Diet and hypolipidemic drug therapy including the use of pravastatin, a new inhibitor of 3-hydroxy-3-methylglutaryl coenzyme-A reductase, were used to treat patients for one year. The total cholesterol concentration decreased from a mean baseline value of 231 mg/dl to a treatment mean value of 165 mg/dl. The mean low-density lipoprotein cholesterol concentration decreased from 157 mg/dl to 93 mg/dl. Masked grading of fundus photographs indicated an improvement in hard exudates in all six patients and a decrease in microaneurysms in four patients. Visual acuity improved in one patient and did not change (one line or less change) in five patients. No remarkable side effects resulting from treatment were observed. Our pilot study suggests that aggressive therapy of diabetic patients with hyperlipidemia may have a beneficial effect on background retinopathy.

To compare colesevelam hydrochloride (Cholestagel), a nonabsorbed hydrogel with bile acid-sequestering properties, with placebo for its lipid-lowering efficacy, its effects on laboratory and clinical safety parameters, and the incidence of adverse events.Following diet and placebo lead-in periods, placebo or colesevelam was administered at 4 dosages (1.5, 2.25, 3.0, or 3.75 g/d) for 6 weeks with morning and evening meals to men and women with hypercholesterolemia (low-density lipoprotein cholesterol level4.14 mmol/L [160 mg/dL]). Patients returned to the clinic every 2 weeks throughout the treatment period for lipid parameter measurements and adverse event assessments. Samples were collected for serum chemistry profiles, hematologic studies, coagulation studies, and vitamin level assessment at baseline and after 6 weeks of treatment.Among the 149 patients randomized, 137 completed the study. Low-density lipoprotein cholesterol concentrations decreased in a dosage-dependent manner by 0.11 mmol/L (4.2 mg/dL) (1.8%) in the 1.5-g/d colesevelam treatment group and up to 1.01 mmol/L (39 mg/dL) (19.1%) in the 3.75-g/d colesevelam treatment group. Low-density lipoprotein cholesterol concentrations at the end of treatment were significantly reduced from baseline levels in the 3.0- and 3.75-g/d colesevelam treatment groups (P = .01 and P.001, respectively). Total cholesterol levels demonstrated a similar response to colesevelam treatment, with an 8. 1% decrease from baseline in the 3.75-g/d treatment group (P.001). High-density lipoprotein cholesterol levels rose significantly in the 3.0- and 3.75-g/d colesevelam treatment groups, by 11.2% (P=.006) and 8.1% (P=.02), respectively. Median triglyceride levels did not change from baseline, nor were there any significant differences between treatment groups. The incidence of adverse events was similar among all groups.Colesevelam therapy is effective for lowering low-density lipoprotein cholesterol concentrations in persons with moderate hypercholesterolemia. It lacks the constipating effect of other bile acid sequestrants, demonstrating the potential for increased compliance.

Plasma high density lipoprotein (HDL) concentrations were increased in five hypercholesterolemic normoglyceridemic patients after removal of plasma low density lipoprotein (LDL) by LDL-pheresis. In each patient up to 80% of circulating LDL was removed by passing plasma through immunoadsorption columns containing antibody to apolipoprotein B immobilized to Sepharose. Rebound of LDL was slow after the procedure: 5-7 days in four non-familial hypercholesterolemic patients and greater than 14 days in one patient with homozygous familial hypercholesterolemia. Plasma HDL rose above the pretreatment baseline during the interval between treatments in four of the five patients. When treatments were repeated weekly, time-averaged plasma LDL was lowered by 40-70%, while plasma HDL cholesterol and apolipoprotein AI were increased up to 2-fold, depending on the degree of LDL lowering. Plasma HDL concentrations fell back to their baseline values when LDL-pheresis was stopped and rose again when treatment was restarted. Thus, LDL-pheresis may augment the therapeutic effectiveness of LDL lowering by raising plasma HDL levels and the concentration of HDL relative to LDL.

The exposure of rat and human lymphoid cells to mitogenic concentrations of phytohemagglutinin resulted in an apparent decrease in cellular K+ without a significant change in cellular Na+ when the cells were washed with isotonic Hepes buffered choline chloride prior to cation determination. The apparent reduction in total cellular Na+ plus K+ concentration, however, was not accompanied by a change in cell volume. We inferred that the constant cell volume could occur only if the lost intracellular K+ was exchanged for an external cation during the washing procedure used to prepare cells for Na+ and K+ measurement. This inference was supported by the quantitative recovery of lost cellular K+ in the choline chloride washing solution and the demonstration that a comparable proportion of 86Rb+ (K+ analogue) 42K+ was lost from prelabelled cells during choline chloride washing. Use of medium 199 with Hanks salts, 150 mM NaCl, or 100 mM MgCl2 as the washing solution did not prevent K+ exchange although exchange was less in the presence of MgCl2. These findings indicate that phytohemagglutinin produces a rapid alteration in lymphocyte plasma membranes so as to allow abnormal K+ exchange. This observation is of importance because investigators who measure intracellular solutes in phytohemagglutinin-treated lymphocytes must consider the possibility of loss during preparative washes. Also, changes in membrane permeability following phytohemagglutinin treatment may modulate mitogenesis and/or permit the transmission of chemical messages between cells.

Four patients with post-partum hemolytic uremic syndrome were treated with plasma exchange using fresh frozen plasma as replacement. Each patient had microangiopathic hemolysis, thrombocytopenia, and progressive renal and hepatic failure. Disseminated intravascular coagulation was a major feature in each case. The microangiopathy and thrombocytopenia resolved in each patient following plasma exchange. Normalization of renal and hepatic function occurred in three patients, including one patient who died as a result of coronary artery dissection. One patient died as a result of an intracerebral bleed. Plasma exchange with fresh frozen plasma replacement appears to be of benefit if used early in the course of post-partum hemolytic uremic syndrome.

Plasma exchange (PE) and intravenous gammaglobulin (IVGG) are potentially effective therapies in immune thrombocytopenic purpura (ITP). In this study, eight patients refractory to IVGG and to prednisone were treated with a protocol of combined PE and IVGG therapy using a single PE on each of 3 consecutive days, followed by 2 consecutive days of IVGG at 1 g per kg. Four of the eight patients responded to the combined therapy with a mean peak platelet count of 132,000 per microliter (range, 74,000 to 225,000/microliter). Responses lasted approximately 2 weeks. These four patients were among the five who had initially responded to IVGG before becoming refractory; none of the three patients without an initial response to IVGG responded to the combined therapy. Age, duration of disease, and splenectomy status did not appear to be related to response to the combined therapy. Two patients began maintenance treatment (1 PE followed by 1 g/kg IVGG on the same day), but both became unresponsive after three treatments. PE combined with IVGG may be a useful treatment for some patients with refractory ITP who have uncontrollable bleeding or require major surgery. The development of resistance to IVGG effect may be mediated by an increase in the level of antiplatelet antibodies. PE, by lowering antiplatelet antibody levels, may then allow IVGG infusion to be effective again in elevating the platelet count.