Search

Early reports showed high mortality from coronavirus disease 2019 (COVID-19). Mortality rates have recently been lower, raising hope that treatments have improved. However, patients are also now younger, with fewer comorbidities. We explored whether hospital mortality was associated with changing demographics at a 3-hospital academic health system in New York. We examined in-hospital mortality or discharge to hospice from March through August 2020, adjusted for demographic and clinical factors, including comorbidities, admission vital signs, and laboratory results. Among 5,121 hospitalizations, adjusted mortality dropped from 25.6% (95% CI, 23.2-28.1) in March to 7.6% (95% CI, 2.5-17.8) in August. The standardized mortality ratio dropped from 1.26 (95% CI, 1.15-1.39) in March to 0.38 (95% CI, 0.12-0.88) in August, at which time the average probability of death (average marginal effect) was 18.2 percentage points lower than in March. Data from one health system suggest that mortality from COVID-19 is decreasing even after accounting for patient characteristics.

Early reports showed high mortality from Covid-19; by contrast, the current outbreaks in the southern and western United States are associated with fewer deaths, raising hope that treatments have improved. However, in Texas for instance, 63% of diagnosed cases are currently under 50, compared to only 52% nationally in March-April. Current demographics in Arizona and Florida are similar. Therefore, whether decreasing Covid-19 mortality rates are a reflection of changing demographics or represent improvements in clinical care is unknown. We assessed outcomes over time in a single health system, accounting for changes in demographics and clinical factors.MethodsWe analyzed biweekly mortality rates for admissions between March 1 and June 20, 2020 in a single health system in New York City. Outcomes were obtained as of July 14, 2020. We included all hospitalizations with laboratory-confirmed Covid-19 disease. Patients with multiple hospitalizations (N=157, 3.3%) were included repeatedly if they continued to have laboratory-confirmed disease. Mortality was defined as in-hospital death or discharge to hospice care. Based on prior literature, we constructed a multivariable logistic regression model to generate expected risk of death, adjusting for age; sex; self-reported race and ethnicity; body mass index; smoking history; presence of hypertension, heart failure, hyperlipidemia, coronary artery disease, diabetes, cancer, chronic kidney disease, or pulmonary disease individually as dummy variables; and admission oxygen saturation, D-dimer, C reactive protein, ferritin, and cycle threshold for RNA detection. All data were obtained from the electronic health record. We then calculated the sum of observed and expected deaths in each two-week period and multiplied each period's observed/expected (O/E) risk by the overall average crude mortality to generate biweekly adjusted rates. We calculated Poisson control limits and indicated points outside the control limits as significantly different, following statistical process control standards. The NYU institutional review board approved the study and granted a waiver of consent.ResultsWe included 4,689 hospitalizations, of which 4,661 (99.4%) had died or been discharged. The median age, and the proportion male or with any comorbidity decreased over time; median real-time PCR cycle threshold increased (indicating relatively less concentration of virus) (Table). For instance, median age decreased from 67 years in the first two weeks to 49 in the last two. Peak hospitalizations were during the fifth and sixth study weeks, which accounted for 40% of the hospitalizations. Median length of stay for patients who died or were discharged to hospice was 8 days (interquartile range, 4-16).Unadjusted mortality dropped each period, from 30.2% in the first two weeks to 3% in the last two weeks, with the last eight weeks being lower than the 95% control limits. Risk adjustment partially attenuated the mortality decline, but adjusted mortality rates in the second-to-last two weeks remained outside the control limits (Figure, Table). The O/E risk of mortality decreased from 1.07 (0.64-1.67) in the first two weeks to 0.39 (0.08-1.12) in the last two weeks.DiscussionIn this 16-week study of Covid-19 mortality at a single health system, we found that changes in demographics and severity of illness at presentation account for some, but not all, of the decrease in unadjusted mortality. Even after risk adjustment for a variety of clinical and demographic factors, mortality was significantly lower towards the end of the study period.Incremental improvements in outcomes are likely a combination of increasing clinical experience, decreasing hospital volume, growing use of new pharmacologic treatments (such as corticosteroids, remdesivir and anti-cytokine treatments), non-pharmacologic treatments (such as proning), earlier intervention, community awareness, and lower viral load exposure from increasing mask wearing and social distancing. It is also possible that earlier periods had a more virulent circulating strain.In summary, data from one health system suggest that Covid-19 remains a serious disease for high risk patients, but that outcomes may be improving.

Long-acting natriuretic peptide (LANP), vessel dilator (VSDL), and atrial natriuretic factor (ANF) consisting of amino acids (aa) 1 to 30, 31 to 67, and 99 to 126, respectively, of the 126-aa ANF prohormone circulate in humans. Among the biologic properties of these peptides is the ability of ANF to decrease intracellular calcium concentrations. To determine if atrial natriuretic peptides are directly related to serum calcium and/or phosphate in healthy normocalcemic humans, we examined 21 24-hour profiles of VSDL, LANP, ANF, and serum calcium and phosphate in 14 healthy humans. VSDL, LANP, and ANF each had significant (P < .001) circadian rhythms, with peak concentrations late during sleep (at 4:00 AM) being nearly twice the concentrations in the afternoon and evening. Serum calcium and phosphate also had significant circadian rhythms (P < .001) with troughs nearly opposite to those of the atrial natriuretic peptides, suggesting that atrial peptides may be important in the modulation of the circadian rhythms of calcium and phosphate. The nearly identical circadian rhythms of the atrial natriuretic peptides and of parathyroid hormone (PTH) reported by others, along with evidence that PTH may increase atrial peptide release, suggest that some of the effects attributed to PTH may be mediated by atrial natriuretic peptides.

Long-acting natriuretic peptide (LANP), vessel dilator (VSDL), and atrial natriuretic factor (ANF) consisting of amino acids 1-30, 31-67, and 99-126 of the 126 amino acid ANF prohormone, respectively, circulate in humans and have potent natriuretic properties. To determine whether these peptides have a direct relationship to serum Na and/or Cl, we examined 21 24-hour profiles of these peptides and Na and Cl in 14 healthy humans. LANP, VSDL, ANF, and Cl had significant (p0.001) circadian rhythms with peak concentrations at 04.00 h. The circadian rhythm of serum Na was exactly opposite. Sodium correlated negatively with LANP (p = 0.021) and ANF (p = 0.007), while Cl correlated positively with LANP (p = 0.003) and VSDL (p = 0.001). These data suggest that the atrial peptides may be important for the maintenance of serum Na and Cl within their normal ranges and in the modulation of their daily circadian rhythms.

STUDY DESIGN To determine whether the normovolemic hemodilution (NH) technique would limit postoperative homologous blood transfusion requirements in 68 patients having multilevel lumbar laminectomies (3-6 levels) with predominant 1- or 2-level instrumented fusions. OBJECTIVE In this setting, to define postoperative homologous blood transfusion requirements using NH. SUMMARY OF BACKGROUND DATA NH limits postoperative homologous blood transfusion requirements following various types of surgical procedures including those on the spine. METHODS NH was used in an attempt to limit postoperative homologous transfusion requirements in 68 patients undergoing lumbar surgery. NH involves the removal of 1 to 2 U of blood replaced with crystalloid (2-4 mL per milliliter of blood harvested). Multiple variables contributing to homologous transfusion requirements were analyzed. RESULTS Using NH, no homologous blood transfusions were required in 52 patients with a mean preoperative hematocrit of 41.3 undergoing average 3.7 level laminectomies with 1.5 level fusions. However, 16 patients with an average preoperative hematocrit of 38.5 undergoing average 4.3 level laminectomies with 1.6 level fusions required transfusion of 31 U of homologous blood after surgery. CONCLUSIONS Using NH, 16 (23.5%) patients required 31 postoperative homologous blood transfusions. By contrast, the remaining 52 patients with similar procedures were able to avoid the use of homologous transfusion.

The use of platelet rich plasma (PRP) in hair restoration surgery reported increased yield when utilized as a graft storage medium (Uebel, 2005).[1][1] When grafts are bathed in activated PRP, there appears to be higher graft survival and quicker healing. Based on five months of experience

Urine samples were collected at 3-hr intervals over a single 24-hr period from each of seven clinically healthy men who ranged in age from 21-25 years. Urines at each collection time were subsequently pooled using 20% of each volume and serially dialyzed against ammonium-barbituric acid buffer (pH 7.35 +/- 0.02), using a cellulose membrane permeable to compounds of less than 12,000-14,000 molecular weight (mw). When the dialyzed portions were then analyzed for total proteins, the sum of proteins in eight pools amounted to 74 mg. A 1 ml aliquot of each pool, representing approximately 50 micrograms of proteins, was concentrated and reconstituted. Approximately 20 micrograms of reconstituted proteins were then subjected to polyacrylamide gel electrophoresis. The stained gel was then scanned by laser densitometry and planimetry. Each aliquot revealed eight segments as identified by Coomassie and silver staining. Their molecular weights, estimated by extrapolation from concurrently run protein standards, and their total protein amounts were: 116,000 mw (9.44 mg), 91,000 mw (3.3 mg), 68,000 mw (11.58 mg), 53,000 mw (2.58 mg), 43,000 mw (9.12 mg), 32,000 mw (7.13 mg), 24,000 mw (4.52 mg) and 20,000 mw (5.27 mg). A statistically significant rhythm (P = 0.022 from ANOVA and 0.011 from Single Cosinor) was found for the excretion of total proteins, with an acrophase in the afternoon (1537) for these diurnally-active subjects.

Human pancreases obtained at autopsy have been analyzed for chromium using flameless atomic absorption spectrophotometry. Both the original sample and the lipid-free sample of 21 pancreases have been digested by means of low temperature plasma ashing. Chromium levels are reported for the following categories of subjects: arteriosclerotic heart disease (5); carcinoma (5); diabetes mellitus (4); cirrhosis of the liver (3); other diseases (4).

The objective of this paper is to describe the Tennessee Valley Authority's efforts and plans in designing an operating and maintenance program that will ensure maximum performance of the electrostatic precipitators at our power generating stations. Detailed operating and maintenance manuals are being prepared for each plant for the use of plant personnel. These manuals include instructions on operation, maintenance, and testing of the precipitators. Instructions on internal and external equipment inspections to be performed during unit operation, emergency and scheduled outages, and problem diagnostic procedures are included to help the plant personnel solve problem areas. Performance curves are included in the manuals which show the effect of gas volume flow, gas temperature, gas resistivity, coal changes, and loss of transformer-rectifier sets on the precipitator performance. In addition, opacity monitors that record continuous opacity readings are being installed at all our plants to assist the plant ...

Mercury levels in thumbnails were determined by instrumental analysis using thermal neutron activation technique. Samples were obtained from 14 subjects employed in the hospital dental service (a), 19 in the clinical laboratories (b), and from 16 hospitalized patients who were not employed in laboratory occupations (c). The average mercury levels in ppm for the respective groups were: (a) dentists, 2.7; technicians, 3.9; assistants, 6.6; (b) male technicians, 0.4; female technicians, 1.9; (c) patients, 0.3.

1. A comparison has been made of plasma values obtained by 5 different methods for uric acid estimation. 2. According to the uricase method, the plasma concentration of uric acid in fasting normal subjects ranged from 1.9-5.1 with average of 3.7 mg. per 100 ml. 3. The closest agreement with the uricase method was obtained with the method of Kern and Stranaky which gave normal values ranging from 2.8 to 4.9 with an average of 3.8 mg. per 100 ml. 4. A variation of about 25 per cent was observed in the plasma uric acid levels over a period of 7 weeks.

This paper describes a test program to evaluate parameters responsible for subnormal performance of several electrostatic fly-ash collectors. Improper flow distribution, exit gas temperature, sulfur in the fuel, and acid dewpoint were found to be variables responsible for poor performance. Remedial steps taken to restore collector efficiency to acceptable levels are discussed.

Human thumbnails were analyzed for trace elements by instrumental analysis using thermal neutron activation technique. The average concentration of metals studied in clinically symptom-free adult female and male subjects were: zinc, 184 vs. 153 ppm; chromium, 6.8 vs. 4.2; selenium, 0.9 vs. 0.6; gold, 2.6 vs. 0.4; mercury, 1.9 vs. 0.4; silver, 0.7 vs. 0.3; cobalt, 0.07 vs. 0.04. A summary of literature reported concentration of metals in human nail is also presented.

Three-hour urine specimens were collected over a period of 27 hours from 11 healthy adult male subjects. Each specimen was analyzed for Na, K, Ca, Mg, and Zn using atomic absorption spectrophotometry. Each sample was also dialyzed, pH 7.35, and subsequently analyzed for Na, K, P, Ca, Mg, Zn, Fe, Pb, Al, Ni, Cu, Mo, Hg, Cr, Cd, and Mn using a multielemental argon-plasma emission system. The data were evaluated on conventional time plots (chronograms) and as computer-determined "cosinor" plots. A population circadian rhythm with a statistical significance was detected for total Na, K, Ca, and Mg, and for nondialyzable Na, K, P, Ca, Zn, and Mo. For almost every element studied the increase from lowest to highest 3-hour group mean along the 24-hour time scale was more than 100%. The 24-hour excretion of Na, K, Ca, Mg, and Zn appeared in good agreement with the so-called "normals." The nondialyzable levels of Fe, Pb, Al, Ni, Cu, Mo, Hg, Cr, Cd, and Mn were similar to the total urinary excretions reported in the literature.

Human electrophoretically pure gamma globulin was found to bind labeled tri-iodothyronine at two levels of tenacity, one which can be characterized as “weak,” the other as “strong.” Serum albumin, on the other hand, was found to have only a “strong” binding capacity. It was shown that a Cohn fraction IV preparation as well as fresh human serum sample possessed the “weak” binding capacity, which was postulated to be the probable source of the so-called “free” hormone fraction that supplies peripheral tissues with hormone. Evidence was presented to show that electrophoretic filter paper may compete for hormone with “weak” protein binding sites. When filter paper strips containing the various proteins at relative levels of concentration at which they normally exist in vivo in the serum, were compared for their relative binding power, the results supported the view that all serum proteins bind thyroid hormone to a greater or lesser degree, and at different binding strengths. It is difficult on the basis of results presented to sustain the hypothesis of the existence of a single specific thyroxine-binding globulin.

A kinetic analysis was determined of an isotopic exchange between a cylinder containing non permeable interacting substance and an infinitely large sink. Fick's second law of diffusion coupled with reversible first-order reaction was used for the analysis. The analysis was made in two conditions, one without mixing and the other with complete mixing of the sample in the cylinder. The equations expressing the amount of radioisotope remaining in the cylinder were derived as a function of time. These show that the appearance of the multi-exponential curves occur whenever the chemical reaction rate constant is close to or smaller than the diffusion constant. If the reaction rate constant is very large, the overall rate of decrease in the isotope in the cylinder is expressed as straight diffusion from a cylinder. The observable “rate constant” in the latter case is a function of the ratio of isotope between “free” and “bound” phases. The equation can be used experimentally to determine the ratio of the isotope in the “bound” and “free” phases of the sample if the membrane is a truly rate-determining step of the isotopic exchange.