Search

Humans expend energy at rest (REE), and this major energy exchange component is now usually estimated using statistical equations that include weight and other predictor variables. While these formulas are useful in evaluating an individual's or group's REE, an important gap remains: available statistical models are inadequate for explaining underlying organ-specific and tissue-specific mechanisms accounting for resting heat production. The lack of such systems level REE prediction models leaves many research questions unanswered. A potential approach that can fill this gap began with investigators who first showed in animals and later in humans that REE reflects the summated heat production rates of individual organs and tissues. Today, using advanced imaging technologies, REE can be accurately estimated from the measured in vivo mass of 10 organ-tissue mass components combined with their respective mass-specific metabolic rates. This review examines the next frontier of energy expenditure models and discusses how organ-tissue models have the potential not only to better predict REE but also to provide insights into how perturbations in organ mass lead to structure-function changes across other interacting organ systems. The introductory ideas advanced in this review provide a framework for future human energy expenditure modelling research.

The purpose of this study was to model data from a head to head comparison of the in vivo fate of hyper-branched PAMAM dendrimers with linear HPMA copolymers in order to understand the influence of molecular weight (MW), hydrodynamic size (Rh) and polymer architecture on biodistribution in tumor-bearing mice using compartmental pharmacokinetic analysis. Plasma concentration data was modeled by two-compartment analysis using Winnonlin® to obtain elimination clearance (E.CL) and plasma exposure (AUCplasma). Renal clearance (CLR) was calculated from urine data collected over 1 week. A plasma-tumor link model was fitted to experimental plasma and tumor data by varying the tumor extravasation (K4, K6) and elimination (K5) rate constants using multivariable constrained optimization solver in Matlab®. Tumor exposures (AUCtumor) were computed from area under the tumor concentration time profile curve by the linear trapezoidal method. Along with MW and Rh, polymer architecture was critical in affecting the blood and tumor pharmacokinetics of the PAMAM-OH dendrimers and HPMA copolymers. Elimination clearance decreased more rapidly with increase in hydrodynamic size for PAMAM-OH dendrimers as compared to HPMA copolymers. HPMA copolymers were eliminated renally to a higher extent than PAMAM-OH dendrimers. These results are suggestive of a difference in extravasation of polymers of varying architecture through the glomerular basement membrane. While the linear HPMA copolymers can potentially reptate through a pore smaller in size than their hydrodynamic radii in a random coil conformation, PAMAM dendrimers have to deform in order to permeate across the pores. With increase in molecular weight or generation, the deforming capacity of PAMAM-OH dendrimers is known to decrease, making it harder for higher generation PAMAM-OH dendrimers to sieve through the glomerulus as compared to HPMA copolymers of comparable molecular weights. PAMAM-OH dendrimer had greater tumor extravsation rate constants and higher tumor to plasma exposure ratios than HPMA copolymers of comparable molecular weights which indicated that in the size range studied, when in circulation, PAMAM-OH dendrimers had a higher affinity to accumulate in the tumor than the HPMA copolymers.

Spherical and rod-shaped gold nanoparticles with surface poly (ethylene glycol) (PEG) chains were characterized for size, shape, charge, poly dispersity and surface plasmon resonance. The nanoparticles were injected intravenously to 6–8 weeks old female nu/nu mice bearing orthotopic ovarian tumors and their biodistribution in vital organs was compared. Gold nanorods were taken up to a lesser extent by the liver, had longer circulation time in the blood, and higher accumulation in the tumors, compared with their spherical counterparts. The cellular uptake of PEGylated gold nanoparticles by a murine macrophage-like cell line as a function of geometry was examined. Compared to nanospheres, PEGylated gold nanorods were taken up to a lesser extent by macrophages. These studies point to the importance of gold nanoparticle geometry and surface properties on transport across biological barriers.

Body mass index (BMI) is now the most widely used measure of adiposity on a global scale. Nevertheless, intense discussion centers on the appropriateness of BMI as a phenotypic marker of adiposity across populations differing in race and ethnicity. BMI-adiposity relations appear to vary significantly across race/ethnic groups, but a collective critical analysis of these effects establishing their magnitude and underlying body shape/composition basis is lacking. Accordingly, we systematically review the magnitude of these race-ethnic differences across non-Hispanic (NH) white, NH black and Mexican American adults, their anatomic body composition basis and potential biologically linked mechanisms, using both earlier publications and new analyses from the US National Health and Nutrition Examination Survey. Our collective observations provide a new framework for critically evaluating the quantitative relations between BMI and adiposity across groups differing in race and ethnicity; reveal new insights into BMI as a measure of adiposity across the adult age-span; identify knowledge gaps that can form the basis of future research and create a quantitative foundation for developing BMI-related public health recommendations.

The ability to achieve high-yield focal plane arrays from Hg1−xCdxTe molecular beam epitaxy material depends strongly on postgrowth wafer analysis. Nondestructive analysis that can determine layer thicknesses as well as alloy compositions is critical in providing run-to-run consistency. In this paper, we incorporate the use of a thin film transmission matrix model to analyze Fourier transform infrared (FTIR) transmission spectra. Our model uses a genetic algorithm along with a multidimensional, nonlinear minimization Nelder-Mead algorithm to determine the composition and thickness of each layer in the measured epitaxial structure. Once a solution has been found, the software is able to predict detector performance such as quantum efficiency and spectral response. We have verified our model by comparing detector spectral data to our predicted spectral data derived from the room-temperature FTIR transmission data. Furthermore, the model can be used to generate design curves for detectors with varying absorber thicknesses and/or different operating temperatures. The consequence of this are reduced cycle times and reduced design variations.

Purpose:This study was undertaken to evaluate simplified methods of human embryo coculture using either attached or nonattached autologous cumulus tissue. Methods:Eight hundred one zygotes were cultured for 48 hr in a prospective, randomized trial comparing culture of embryos either with intact cumulus tissue, with cumulus tissue added to the droplet of culture medium, or without any cumulus tissue. In a follow-up study, embryo quality, pregnancy rates, and implantation rates were compared in 120 consecutive patients undergoing in vitro fertilization with a coculture system using cumulus tissue compared to a cohort of 127 patients undergoing IVF immediately preceding the institution of the coculture protocol. Results:Embryo morphology was significantly improved (P < 0.05) following culture with attached cumulus tissue (5.61 ± 0.29) and culture with added cumulus tissue (4.72 ± 0.31) compared to that of embryos grown in culture medium without cumulus tissue (3.95 ± 0.26). The clinical pregnancy rate improved from 39.4% (50/127) to 49.2% (59/120) following institution of a system of coculture with attached cumulus tissue. Conclusions:These data indicate that a simple coculture system using autologous cumulus tissue can result in improved embryo morphology, implantation rates, and clinical pregnancy rates during in vitro fertilization. This coculture system is simple, is non-labor intensive, and eliminates many of the risks which may be present in other embryo coculture systems.

Water deficits during flowering decrease the number of seed-bearing pods in soybean (Glycine max L. Merr.). Failure to set pods may indicate an inherent sensitivity to low tissue water potential (Ψ w ) at critical stages of flower development. To test this, we measured the water status and pod set of flowers exposed to water deficits at various stages of development from bud to early ovary (pod) expansion. In well-watered (control) plants, the Ψ w of buds, flowers, and pods were about 0.2 to 0.3 MPa lower than leaf Ψ w at midday

This study analyzed the role that the cumulus oophorus may play in the selection of morphologically normal sperm and the induction of the acrosome reaction. Using the triple stain technique, sperm morphology and acrosomal status were compared between sperm that penetrated the cumulus during in vitro fertilization and sperm from outside the cumulus. The mean percentage of morphologically normal sperm in the samples was 54 +/- 2.8 and increased (p0.05) to 67 +/- 2.6 within the cumulus. Tapered sperm were significantly decreased (p0.05) within the cumulus. The percentage of sperm undergoing the acrosome reaction significantly increased (p0.05) from 14.5 +/- 1.5 to 24.5 +/- 1.9 when incubated with a cumulus mass, and further increased to 49 +/- 3.3 when incubated with mature, expanded cumulus tissue containing an oocyte. These data indicate that human cumulus oophorus plays an active role in the selection of morphologically normal sperm, and influences the ability of the sperm to undergo the acrosome reaction.

The biodistribution profile of a series of linear N-(2-hydroxylpropyl)methacrylamide (HPMA) copolymers was compared with that of branched poly(amido amine) dendrimers containing surface hydroxyl groups (PAMAM-OH) in orthotopic ovarian-tumor-bearing mice. Below an average molecular weight (MW) of 29 kDa, the HPMA copolymers were smaller than the PAMAM-OH dendrimers of comparable molecular weight. In addition to molecular weight, hydrodynamic size and polymer architecture affected the biodistribution of these constructs. Biodistribution studies were performed by dosing mice with (125)iodine-labeled polymers and collecting all major organ systems, carcass, and excreta at defined time points. Radiolabeled polymers were detected in organ systems by measuring gamma emission of the (125)iodine radiolabel. The hyperbranched PAMAM dendrimer, hydroxyl-terminated, generation 5 (G5.0-OH), was retained in the kidney over 1 week, whereas the linear HPMA copolymer of comparable molecular weight was excreted into the urine and did not show persistent renal accumulation. PAMAM dendrimer, hydroxyl-terminated, generation 6.0 (G6.0-OH), was taken up by the liver to a higher extent, whereas the HPMA copolymer of comparable molecular weight was observed to have a plasma exposure three times that of this dendrimer. Tumor accumulation and plasma exposure were correlated with the hydrodynamic sizes of the polymers. PAMAM dendrimer, hydroxyl-terminated, generation 7.0 (G7.0-OH), showed extended plasma circulation, enhanced tumor accumulation, and prolonged retention with the highest tumor/blood ratio for the polymers under study. Head-to-head comparative study of HPMA copolymers and PAMAM dendrimers can guide the rational design and development of carriers based on these systems for the delivery of bioactive and imaging agents.

Endosperm development in ovules was studied from the time of fertilization through the P5 stage in setting flowers of soybean and provides a basis for comparison with ovules of similar age from flowers programed to abscisse

6-benzylaminopurine (BAP) delays leaf abscission of soybean Glycine max (L.) Merr. Abscission of the distal pulvinus of primary leaves was induced in 12-d-old seedlings or explants by removal of the leaf blade. BAP applied to the cut end of the pulvinus following leaf blade removal delayed abscission. Discoloration of the pulvinus occurred before abscission commenced and the number of grana in chloroplasts within cortical parenchyma cells of the pulvinus decreased over time following leaf blade removal

Flower and pod abscission limit soybean yield. A system for quantifying flower and pod development based on the morphological appearance of the flower prior to and following anthesis has been developed to aid in studies of pod abscission. Changes in the appearance of the corolla, primarily the banner petal, are used to distinguish the different stages of the system. External pistil dimensions have been correlated with internal features for each stage of development. From anthesis to pod set, pistil length and weight increase almost two- and fivefold, respectively, and ovule development progresses from unfertilized egg cells to embryos surrounded by cellular endosperm. Pod dimensions are correlated with ovule length and width and embryo cell number. Flower and pod stages can be determined in situ, thus permitting non-destructive observation and experimental manipulation of flowers or pods without necessarily impeding their development. Stages have been identified that indicate precisely when pod set occurs and when young pods cease growing and ultimately abscise. This system of flower and pod staging is useful in studies designed to assess effects of abiotic or biotic stress and genetic factors on pod set and abortion.

The cytokinin 6-benzylaminopurine (BAP) increases pod set of soybean Glycine max (L.) Merr. This study was performed to determine the effect of site and method of BAP application on pedicel abscission and the accompanying changes in rachis anatomy. Spraying racemes with BAP in solution, or applying in a lanolin suspension to proximal nodes on a rachis where proximal pedicels had been excised, delayed pedicel abscission at distal nodes. Applying BAP in lanolin to distal pedicels following flower excision failed to delay their abscission. BAP caused rachis swelling only when pods were present, but BAP could delay pedicel abscission either in the presence or absence of pods. These results suggest that rachis swelling following BAP treatment does not have a causal relationship to a delay or decrease of pedicel abscission.

Lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae), larval injury to the root-hypocotyl region of greenhouse-reared ‘Florunner’ peanut, Arachis hypogaea L., plants was investigated by determining the size and distribution of feeding sites. The percent injury to periderm, cortex, phloem, and xylem tissues also was estimated. Tissue loss due to insect feeding was measured for only the most prominent of several wound sites on each stem axis. Percent injury to principal tissues was estimated by planimetric methods. The lesser cornstalk borer caused significant injury to the periderm, cortex, and the phloem on mainstems of peanut plants. Mean percent injury was 31.67% for the periderm and cortex, 16.78% for phloem, and only 0.19% for the xylem. Approximately 91% of all feeding sites occurred on the mainstem or were contiguous with the mainstem and a branch. The frequently of plants with feeding sites declined linearly with increasing number of sites. These data support the hypothesis that root growth declines with increasing larval injury to phloem and xylem (food and water conducting tissues, respectively) in the root-hypocotyl region.

Previous studies have indicated that sperm quality may be related to unexplained recurrent pregnancy loss. This study evaluated the degree of sperm DNA fragmentation using the TUNEL assay on sperm from 24 couples with unexplained recurrent pregnancy loss (RPL) compared to sperm from 2 control groups: donors of known fertility and unscreened men from the general population. The percentage of sperm staining positive for DNA fragmentation was increased (p < .001) in the RPL group (38 +/- 4.2) compared to the donor (11.9 +/- 1.0) or general population (22 +/- 2.0) control groups. In the RPL group, no correlation was observed between semen quality parameters and the TUNEL data. These data indicate that some RPL patients have a significant increase of sperm DNA fragmentation, which may be causative of pregnancy loss in some patients.

This study demonstrates the selective tumor targeting and the antitumor efficacy of the N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-bound mesochlorin e6 monoethylenediamine (Mce6) and HPMA copolymer-bound Adriamycin (ADR) in combination photodynamic therapy (PDT) and chemotherapy against human ovarian OVCAR-3 carcinoma xenografted in female athynmic mice. The concentrations of Mce6 and ADR in blood and tissues, in free or HPMA copolymer-bound form, were determined by fluorescence and high-performance liquid chromatography fluorescence assays, respectively. Xenograft responses to single and combination therapies were recorded. The peak concentration of HPMA copolymer-Mce6 conjugate in tumor was achieved 18 h after administration. For HPMA copolymer-bound drugs, the concentration ratios of liver and spleen versus muscle were significantly higher than those of free drugs. The HPMA copolymer-bound drugs demonstrated selective targeting and accumulation in the tumor, probably attributed to the enhanced permeability and retention effect. In vivo studies revealed that all tumors in the treatment groups showed significant responses after receiving any of the various types of therapy as compared with controls (P0.001). PDT with HPMA copolymer-Mce6 conjugate (PDTMC) at a dose of 13.4 mg/kg (1.5 mg/kg of Mce6 equivalent) and light doses of 110 J/cm2 at 12 and 18 h, respectively, resulted in significant suppression of the growth of OVCAR-3 tumors. Three courses of chemotherapy using 35 mg/kg (2.2 mg/kg of ADR equivalent) of HPMA copolymer-ADR conjugate (CHEMO) were effective in suppressing the growth of tumors. Single PDTMC plus multiple CHEMO exhibited significantly greater therapeutic efficacy than multiple CHEMO. In the group of mice receiving multiple PDTMC, tumor recurrence became obvious after day 20. However, 10 of 12 tumors exhibited complete responses in the group of mice receiving multiple PDTMC plus multiple CHEMO. The least to most effective treatments were ranked as follows: multiple CHEMOsingle PDTMC plus multiple CHEMOmultiple PDTMCmultiple PDTMC plus multiple CHEMO. The results clearly demonstrate that: (a) HPMA copolymer-bound drugs exhibited selective tumor accumulation contrary to free drugs; (b) PDT using HPMA copolymer-Mce6 conjugate with multiple light irradiations was a better therapy than that with single light irradiation; and (c) combination chemotherapy and photodynamic therapy with HPMA copolymer-ADR and HPMA copolymer-Mce6 conjugates was the most effective regimen.

Two isoforms of prostaglandin G/H synthase, PGS-1 and PGS-2, catalyze the formation of prostaglandins (PG). Nonselective PGS inhibitors, e.g., indomethacin, reduce the number of ovulations and PG levels in many animal models. This study evaluated the effects of the selective PGS-2 inhibitor NS-398, compared to indomethacin, on ovulation number and on PG and steroid production both in vivo and in vitro in the rat. NS-398 reduced the synthesis of PGE2 in isolated, LH-stimulated preovulatory follicles incubated in vitro. The inhibition by NS-398 was similar to that of indomethacin. Maximal inhibition was noted from 0.1 microM. Neither progesterone nor cAMP production was affected by NS-398 or indomethacin. The effect of in vivo administration of NS-398 (1, 3, or 10 mg/kg BW, s. c.) to proestrous rats 1 h after the injection of an ovulatory dose of hCG was monitored in follicles extirpated 10 h after hCG. These follicles were incubated in vitro, and NS-398 dose-dependently reduced PGE2 production. The synthesis of cAMP and progesterone was not altered. In separate experiments, the same doses of NS-398 were injected to determine their effect on ovulation in vivo. The number of ovulations was decreased by the highest dose of NS-398. In the in vitro ovarian perfusion model, NS-398 (10 microM) reduced the number of ovulations initiated by LH and isobutylmethylxanthine. Lower doses of NS-398 (0.1 and 1 microM) were less effective. The production of prostanoids (PGE2, PGF2alpha, and 6-keto-PGF1alpha) was reduced in a dose-dependent manner by NS-398. The secretion of steroids was not affected. This study demonstrates that selective inhibition of PGS-2 by NS-398 reduces LH/hCG-stimulated production of prostanoids and the number of ovulations both in vivo and in vitro. These results provide direct evidence to strengthen the role of the inducible, granulosa cell-expressed PGS-2 as one of the key regulators in the ovulatory process and also document that the elevated and perhaps sustained levels of PG are obligatory for ovulation.

Hemoglobin A1c (HbA1c) is a stable minor Hb variant formed in vivo by posttranslational modification by glucose, originally identified by using cation exchange chromatography, and containing primarily glycated N-terminal beta-chains. However, the structure(s) of the quantified species has not been elucidated, and the available methods lack a reference standard. We used electrospray ionization mass spectrometry to determine the extent of glycation of samples separated by boronate affinity and/or cation exchange chromatography. Analyses of clinical samples were consistent with the curvilinear relationship of patient glucose and HbA1c. As glycation increased, the ratio of beta-chain to alpha-chain glycation increased, and the number of glycation sites on the beta-chain increased, although these were relatively minor components. We found several glycated species that cochromatographed with HbA1c on cation exchange, including species with both glycated alpha- and beta-chains, nonglycated alpha- and glycated beta-chains, and multiply glycated beta-chains. The combined use of affinity and cation exchange chromatography with structural confirmation by electrospray ionization mass spectrometry was found to be useful in producing samples of sufficient purity for the standardization of glycohemoglobin clinical assays.

Eicosanoids, the active metabolites of arachidonic acid, are grouped into cyclooxygenase products (prostaglandins [PGs] and thromboxanes) and lipoxygenase products (leukotrienes [LTs] and lipoxins). Numerous studies suggest a role for the lipoxygenase system in ovulation. The aim of this study was to further characterize the effects of lipoxygenase inhibition and the interactions of the lipoxygenase and cyclooxygenase systems in the rat ovary during ovulation. The lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA), was administered in vivo and in the isolated perfused rat ovary to determine its effect on ovulation rate. The in vivo study confirmed the inhibitory effect of NDGA, and in the perfusion experiments, NDGA caused a dose-dependent reduction in the ovulation rate. To further define the interaction between the lipoxygenase and cyclooxygenase systems, a second set of perfusions was performed with NDGA (10 microM) and the combination of NDGA (10 microM) plus a nonselective cyclooxygenase inhibitor, indomethacin (10 microM). NDGA significantly reduced the number of ovulations compared to that in controls. The ovulation rate for the combination of NDGA+indomethacin was also significantly lower than in controls but not different from that in the NDGA-treated group. Steroidogenesis was decreased only in the NDGA+indomethacin perfusions. Ovarian tissue PGE2 and PGF2alpha levels in the NDGA-treated ovaries were significantly suppressed compared to those in controls. Almost a complete block of PGE2 and PGF2alpha was seen in the NDGA+indomethacin group. LTB4 levels in the 10-h-perfused ovarian tissues were significantly decreased by NDGA compared to those in control tissues. Furthermore, LTB4 (3 microg added twice) completely reversed the inhibitory effect of 0.1 microM NDGA on ovulation rate and partially reversed the effect of 10 microM NDGA in the perfusion model. These results demonstrate that the products of the lipoxygenase pathway, especially LTB4, are important in the process of ovulation in this cyclically ovulating species. The interconnected lipoxygenase and cyclooxygenase pathways may optimize ovulation and facilitate steroidogenesis.

This study characterizes the efficacy and toxicity of: (a) free Adriamycin and N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-Adriamycin conjugate (P-A); (b) free and HPMA copolymer-meso-chlorin e6 monoethylene diamine disodium salt (Mce6) conjugate (P-C) and light-induced photodynamic therapy; and (c) combinations of the HPMA copolymer conjugates (P-A and P-C) in the destruction of human epithelial ovarian carcinoma heterotransplanted in the nude mouse (OVCAR-3). Eight-week-old female nu/nu mice were injected in both flanks with 0.04-0.05 cm3 OVCAR-3 solid tumor dispersed in media. When bilateral tumors reached a minimum volume of 0.18 cm3 (one axis, 2.0-mm minimum) and demonstrated consistent growth, the experiments were initiated. Drugs were given i.v. unless otherwise noted. Tumor-bearing mice were allocated to the following protocols: (a) Adriamycin at 1 mg/kg, P-A at 30 mg/kg (2.2 mg/kg Adriamycin equivalent), and controls (n = 6 each); (b) Mce6 and light (2 h after administration: 650 nm light for 15 min to deliver 220 J/cm2) at 1.25, 2.5, 5, and 10 mg/kg (n = 6 each), 2.5 mg/kg i.p. (n = 4), and controls (n = 6); (c) P-C at 12.5, 25, and 75 mg/kg (1.5, 2.9, and 8.7 mg/kg Mce6 equivalent, respectively with light (18 h after administration; 650 nm light for 15 min to deliver 220 J/cm2), P-C at 25 mg/kg (2.9 mg/kg Mce6 equivalent) with no light administration, and controls (n = 7 each); and (d) a combination of P-A (30 mg/kg, 2.2 mg/kg adriamycin equivalent) and P-C (12.5 and 75 mg/kg, 1.5 mg/kg and 8.7 mg/kg Mce6 equivalent, respectively) with and without light (n = 7 each; 18 h after administration; 650 nm light for 15 min to deliver 220 J/cm2) and controls (n = 12). Tumor volumes and animals weights were assessed for significant differences from the treated and controls groups by Student's t test. Adriamycin (1 mg/kg) and P-A (30 mg/kg. 2.2 mg/kg Adriamycin equivalent) caused less than a 10% weight loss, and treated tumor volumes (day 10-32) were significantly less than those of controls (all P0.045). Mce6 (2.5-10 mg/kg i.v.), caused tumor regression in 80% of tumors and a shock syndrome in 17-83%. i.p. dosing (2.5 mg/kg) was uniformly fatal. Mce6 at 1.25 mg/kg did not show reproducible efficacy. P-C with light (25 and 75 mg/kg, 2.9 and 8.7 mg/kg Mce6 equivalent, respectively) demonstrated significant tumor destruction (P0.003) but not complete ablation. The combinations of P-A (30 mg/kg, 2.2 mg/kg Adriamycin equivalent) plus P-C (12.5 and 75 mg/kg; 1.5 mg/kg and 8.7 mg/kg of Mce6 equivalent, respectively) with light resulted in tumor volumes that were significantly less than control tumor volumes and the tumor volumes of mice receiving either P-A (30 mg/kg, 2.2 mg/kg Adriamycin equivalent) or P-C with light (12.5 or 75 mg/kg. 1.5 or 8.7 mg/kg Mce6 equivalent, respectively) alone (all P0.02). P-C (75 mg/kg, 8.7 mg/kg Mce6 equivalent) added to P-A (30 mg/kg, 2.2 mg/kg Adriamycin equivalent) resulted in complete tumor ablation. Free Mce6 demonstrates a narrow margin of safety, which is extended by incorporation into HPMA copolymers. P-A demonstrates safety and efficacy in vivo. The combined chemotherapy and photodynamic therapy of P-A (30 mg/kg, 2.2 mg/kg Adriamycin equivalent) with P-C and light (12.5 and 75 mg/kg 1.5 and 8.7 mg/kg Mce6 equivalent, respectively) was nontoxic and allowed us to attain a significant improvement in tumor cures than those obtained by P-A or P-C with light alone.

Few distinct surface markers have been identified for endocrine cells, but antibodies directed against hormonal epitopes are widely available. In this study, human fetal pancreatic beta cells were identified on the flow cytometer by intracellular staining for insulin. A paraformaldehyde based permeabilization scheme was used which preserves surface staining and helps maintain cell integrity while allowing antibodies access to compartments within the cell interior. Cells were first stained for surface antigens, fixed in paraformaldehyde, and then permeabilized in phosphate buffered saline containing 0.2 percent Tween. Intracellular staining was accomplished using a fluorescein conjugated anti-insulin monoclonal antibody. In this manner, major histocompatibility complex Class II antigen expression was documented on beta cells exposed to interferon gamma. This study demonstrates the feasibility of using hormonal content to identify endocrine cells by flow cytometry while simultaneously staining for surface antigens.

The approach to gestational diabetes mellitus has altered markedly in the last decade; it is guided by universal screening and an impetus to establish 24-h euglycemia in these women, through serial measurements of blood glucose by home monitoring and glycated hemoglobin. The best screening and diagnostic procedures for documentation of gestational diabetes remain the subject of considerable debate. Improved outcome has been associated with improved levels of glycemia. While continuous monitoring of blood glucose is not practical, four blood glucose checks per day (fasting and 1 h after the start of each meal) had proven feasible and allowed the development of treatment strategies designed to maintain fasting blood glucose less than 80 mg/dl and post-prandial glucose less than 140 mg/dl. Diet prescriptions that help achieve these goals include a caloric intake sufficient to avoid the ketonuric threshold (30 kcal/kg in women 80-120% ideal body weight) and less than or equal to 40% carbohydrate. Seventy-five percent of women with gestational diabetes respond to diet therapy alone. Cardiovascular conditioning exercise for 20 min three times per week has been shown to be useful in lowering both fasting and post-prandial glucose levels. If diet and exercise do not achieve the requisite glucose levels, insulin therapy based on body weight and gestational age is instituted.

We have recently completed a double-blind, placebo-controlled, noncrossover study, the goal of which was to determine whether cetiedil citrate (cetiedil) could affect the course of vaso-occlusive crises in sickle cell disease. Patients, who presented to the emergency room at least 4 but no more than 24 hours after the onset of a painful vasoocclusive crisis severe enough to require hospitalization, were considered candidates for the study. Each patient received either placebo or cetiedil at one of the following three dosages: 0.2, 0.3, or 0.4 mg/kg body weight. The assigned drug dosage was given as a 30 minute intravenous infusion every 8 hours for 4 consecutive days. A total of 67 patients was enrolled in the study. Cetiedil, at its highest dosage (0.4 mg/kg body weight), was found to be significantly superior to placebo both in reducing the number of painful sites present on all 4 treatment days and in shortening the total time in crisis. No serious adverse reactions were observed during the course of the study. We conclude that cetiedil, given at a dosage of 0.4 mg/kg body weight, is therapeutically advantageous for sickle cell crisis.

Total hemolytic complement (CH50) and activation of the alternate mechanism were measured in eight patients before and after splenectomy and compared to similar measurements made in a control group of patients following other abdominal surgery. In the splenectomy group, alternate-pathway-mediated activation of C3 was significantly different from the controls. The mean five-day postsplenectomy value of 16 percent for the immunoelectrophoretic conversion of C3 to C3i was depressed (p

Accelerated fibrinogen disappearance in diabetic patients is reversible with normalization of blood glucose. To define the time course of this reversal, we measured 125I-fibrinogen disappearance in 19 diabetic patients experiencing acute changes in blood glucose, as monitored and controlled by a microprocessor-controlled closed loop insulin infusion system (artificial beta cell). The data were corrected for blood volume dilutional changes and fit to a model describing two sequential exponential functions and a single exponential function. The sequential model provided the best fit for all but one patient. This indicates that there were two distinct rates of fibrinogen disappearance and suggests that the time course of reversal of accelerated fibrinogen disappearance in diabetic patients is very rapid, if not immediate. Rapid fibrinogen turnover during hyperglycemia was temporally associated with vascular volume changes, reflected as dilutional changes of 51Cr-RBC concentrations. These findings were also associated with an increase in pulse pressure during hyperglycemia, suggesting blood volume expansion due to an osmotic mechanism. The results of this study suggest a picture of vascular volume expansion and contraction, perhaps secondary to the osmotic effects of hyperglycemia. Accelerated fibrinogen turnover associated with these events may be related to increased vascular permeability and/or increased fibrin formation. These events, in concert, may contribute to the initiation and/or propagation of diabetic vascular sequelae.

Fibrinogen survival and turnover were examined in 15 adult-onset diabetic patients. (125)I-labeled fibrinogen was prepared from each patient during the period of poor carbohydrate control, or hyperglycemic period, and fibrinogen survival determined. Improved control was established in each patient and during this euglycemic period, fibrinogen survival was determined simultaneously with (125)I-fibrinogen saved from the hyperglycemic period and (131)I-labeled fibrinogen prepared from the patient during the euglycemic period. The results confirm reduced fibrinogen survival in hyperglycemic diabetic patients and demonstrate reversal of the fibrinogen abnormality when euglycemia is achieved. The results of the double-label experiments in the euglycemic period suggest that the fibrinogen molecule is not altered functionally and that an abnormal plasma or vascular environment is a more likely basis for reduced fibrinogen survival during hyperglycemia. Electrophoretic and chromatographic experiments demonstrated no gross chemical differences between the fibrinogens prepared from the hyperglycemic and euglycemic periods and normal fibrinogen. Fibrinogen survival gave a better correlation with serial glucose measurements than with correction of hemoglobin A(Ic) levels indicating that the reduced fibrinogen survival noted in diabetics is a rapidly reversible phenomenon. During the hyperglycemic period, pharmacological intervention with aspirin and dipyrimadole was attempted to examine the role of platelets in reduced fibrinogen survival. No significant change in fibrinogen survival was observed. Heparin infusion during hyperglycemia normalized the fibrinogen kinetics of hyperglycemic diabetic patients, suggesting that reduced fibrinogen survival during hyperglycemia is secondary to an effect on thrombin or one of its antagonists.

The Strecker degradation reaction was evaluated as a means of modifying hemoglobin in vitro, utilizing ninhydrin as a model compound. Ninhydrin led to modification of hemoglobin (when incubated with hemoglobin or red cells) at physiologic temperature and pH. Isoelectric focusing documented the formation of new hemoglobin bands, all with decreased (more negative) isoelectric points that hemoglobin A. Both alpha and beta chains were modified to an equal degree, although electrophoretic studies documented two modified species of alpha-chains and three modified species of beta-chains. Amino acid analysis of modified hemolysate following NaB3H4 reduction revealed peaks that coeluted with deaminated valine, epsilon-deaminated lysine, and a product with the guanidino group of arginine. The oxygen affinity of hemoglobin increased following its incubation with increasing concentrations of ninhydrin. These studies suggest that ninhydrin is representative of a class of carbonyl compounds that could be utilized to specifically modify that structure and function of hemoglobin variants.

In an attempt to understand the variability of the hematologic response to oral sodium cyanate, iron metabolism was studied in a group of 39 patients with sickel cell disease. Eleven of the 39 patients were found to have no stainable iron in the marrow despite the fact that patients with sickle cell disease are generally considered to have hemosiderosis. The mean per cent saturation and total iron-binding capacity were in the low-normal range in sickle cell patients whether or not stainable iron was present in the bone marrow aspirate. Serum ferritin concentrations, on the other hand, were found to be high in both groups (greater than 500 mu g/liter) when compared to controls (60 mu g/liter). The high serum ferritin levels denoted significant total-body iron deposition which may be unavailable for normal metabolic processes. One patient with no stainable iron in the bone marrow aspirate did respond to iron therapy alone with an increase in hemoglobin concentration. Serum ceruloplasmin levels were also found to be high in sickle cell disease patients. The ability to respond to oral cyanate therapy was correlated with the amount of stainable iron in the bone marrow aspirate. These studies emphasize the necessity of a reevaluation of iron metabolism in the pathophysiology and treatment of sickle cell disease.

Total hemolytic complement activity (CH50), immuno-electrophoretic conversion of Factor B (C3PA), and of C3 were studied in 16 patients with sickle cell disease in a steady state, eight patients in crisis, and ten patients with β-thalassemia major anemia maintained on a constant transfusion regimen. Patients with sickle cell disease in a steady state have moderatley 56 (percent) depressed conversion of Factor B in addition to markedly decreased conversion of C3 in four of ten patients. One of the three sickle cell patients and two of the four thalassemia patients with low C3 conversion levels have died subsequent to the studies. The combination of chronically decreased Factor B conversion in the face of markedly decreased C3 conversion may make these patients occasionally vulnerable to overwhelming infection analagous to the situation seen in postsplenectomy cases.

The recent suggestion that the administration of aspirin might be useful in the treatment of sickle-cell anemia has been further studied and found to be without basis. After incubation with aspirin, sickle-cell erythrocytes are not inhibited from sickling after deoxygenation. In addition, although aspirin does transfer the acetyl group to hemoglobin both in vitro and in vivo , in our experiments the reaction does not result in any alteration in the oxygen equilibrium of either intact erythrocytes or hemoglobin in solution. Furthermore, patients maintained on long-term aspirin administration also showed no shift in the oxygen affinity of their blood.