Effects of acetate, propionate, and pH on volatile fatty acid thermodynamics in continuous cultures of ruminal contents.

To investigate the effects of acetate, propionate, and pH on thermodynamics of volatile fatty acids (VFA) in the rumen, a dual-flow continuous culture study was conducted to quantify production of major VFA, interconversions among the VFA, and H2 and CH4 emissions in a 4 × 4 Latin square design. The 4 treatments were (1) control: pH buffered to an average of 6.75; (2) control plus 20 mmol/d of infused acetate (InfAc); (3) control plus 7 mmol/d of infused propionate (InfPr); and (4) a 0.5-unit decline in pH elicited by adjustment of the buffer (LowpH). All fermentors were fed 40 g of a pelleted diet containing whole alfalfa pellets and concentrate mix pellets (50:50) once daily. After 7 d of treatment, sequential, continuous infusions of [2-13C] sodium acetate (3.5 mmol/d), [U-13C] sodium propionate (2.9 mmol/d), and [1-13C] sodium butyrate (0.22 mmol/d) were carried out from 12 h before feeding for 36 h. Filtered liquid effluent (4 mL) was sampled at 0, 2, 4, 6, 8, 12, 16, and 22 h after feeding, and assessed for VFA concentrations, with another filtered sample (20 mL) used to quantify aqueous concentrations of CH4 and H2. Headspace CH4 and H2 gases were monitored continuously. Ruminal microbes were isolated from the mixed effluent samples, and the microbial community structure was analyzed using the 16S rRNA amplicon sequencing technique. The digestibility of neutral detergent fiber, acid detergent fiber, and starch and microbial C sequestrated from VFA were not affected by treatments. The LowpH treatment increased net propionate production and decreased H2 and CH4 headspace emissions, primarily due to shifts in metabolic pathways of VFA formation, likely due to the observed changes in bacterial community structure. Significant interconversions occurred between acetate and butyrate, whereas interconversions of other VFA with propionate were relatively small. The InfAc and InfPr treatments increased net acetate and propionate production, respectively; however, interconversions among VFA were not affected by pH, acetate, or propionate treatments, suggesting that thermodynamics might not be a primary influencer of metabolic pathways used for VFA formation.

Robustly estimating the marginal likelihood for cognitive models via importance sampling.

Recent advances in Markov chain Monte Carlo (MCMC) extend the scope of Bayesian inference to models for which the likelihood function is intractable. Although these developments allow us to estimate model parameters, other basic problems such as estimating the marginal likelihood, a fundamental tool in Bayesian model selection, remain challenging. This is an important scientific limitation because testing psychological hypotheses with hierarchical models has proven difficult with current model selection methods. We propose an efficient method for estimating the marginal likelihood for models where the likelihood is intractable, but can be estimated unbiasedly. It is based on first running a sampling method such as MCMC to obtain samples for the model parameters, and then using these samples to construct the proposal density in an importance sampling (IS) framework with an unbiased estimate of the likelihood. Our method has several attractive properties: it generates an unbiased estimate of the marginal likelihood, it is robust to the quality and target of the sampling method used to form the IS proposals, and it is computationally cheap to estimate the variance of the marginal likelihood estimator. We also obtain the convergence properties of the method and provide guidelines on maximizing computational efficiency. The method is illustrated in two challenging cases involving hierarchical models: identifying the form of individual differences in an applied choice scenario, and evaluating the best parameterization of a cognitive model in a speeded decision making context. Freely available code to implement the methods is provided. Extensions to posterior moment estimation and parallelization are also discussed.

Representing interconversions among volatile fatty acids in the Molly cow model.

The Molly cow model uses fixed stoichiometric coefficients for predicting volatile fatty acid (VFA) production from the fermented individual dietary nutrient fractions of forage and concentrate. We previously showed that predictions of VFA production had large errors and hypothesized that it was due to a lack of representation of carbon exchange among VFA. The objectives of the present study were to add VFA interconversion equations based on thermodynamics to the Molly cow model and evaluate the effect of these additions on model accuracy and precision of VFA predictions. Previously described thermodynamic equations were introduced to represent interconversions among VFA. The model was further modified to predict de novo acetate, propionate, and butyrate production coefficients based on forage-to-concentrate ratios rather than discrete, fixed sets of coefficients for forage-based, concentrate-based, and mixed diets. Both the original model and the modified one were reparameterized and evaluated against a common data set containing 8 studies reporting pH, VFA concentration, and VFA production rates using isotope dilution techniques and 62 studies reporting VFA concentrations and pH. Evaluations after parameter estimation revealed that predictions of VFA production rates were not improved, with root mean squared prediction errors (RMSPE) of 77, 60, and 51% for acetate, propionate, and butyrate, respectively, for the revised model versus 75, 63, and 55, respectively, for the original model. The RMSPE for predictions of VFA concentrations were reduced from 28, 46, and 40% to 22, 31, and 26% for acetate, propionate, and butyrate, respectively, simply by rederiving the VFA coefficients, but minimal further improvement was achieved with the addition of thermodynamically driven interconversion equations (RMSPE of 21, 32, and 27% for acetate, propionate, and butyrate, respectively). Thus, the results indicate that thermodynamically driven interchanges among VFA, as represented in this study, may not be a primary determinant for the accuracy of predictions of net production rates. Including the effect of pH on VFA absorption reduced the mean bias of propionate production and slope bias of acetate production, but not the overall RMSPE. The larger prediction errors for VFA production as compared with concentrations suggest the data quality may not be high, or that our representation of VFA production and absorption as well as ruminal digestion is inadequate. Additional data are required to discriminate among these hypotheses.

The seroepidemiology of human herpesvirus 8 (Kaposi's sarcoma-associated herpesvirus): distribution of infection in KS risk groups and evidence for sexual transmission.

Striking differences in Kaposi's sarcoma (KS) risk for AIDS patients who acquire HIV via homosexual activity and those whose HIV infections derive from blood product exposure suggest the presence of a sexually transmitted agent other than HIV in the development of KS. Using an immunofluorescence assay, we examined serum samples from 913 patients for the presence of antibody specific for infection by human herpesvirus 8 (HHV8), an agent whose genome is regularly found in KS tissue. The distribution of HHV8 seropositivity conforms to that expected for a sexually transmitted pathogen and tracks closely with the risk for KS development. Our data support the inference that this virus is the etiologic cofactor predicted by the epidemiology of KS.

Corn silage versus corn silage:alfalfa hay mixtures for dairy cows: effects of dietary potassium, calcium, and cation-anion difference.

Corn silage (CS) has replaced alfalfa hay (AH) and haylage as the major forage fed to lactating dairy cows, yet many dairy producers believe that inclusion of small amounts of alfalfa hay or haylage improves feed intake and milk production. Alfalfa contains greater concentrations of K and Ca than corn silage and has an inherently higher dietary cation-anion difference (DCAD). Supplemental dietary buffers such as NaHCO(3) and K(2)CO(3) increase DCAD and summaries of studies with these buffers showed improved performance in CS-based diets but not in AH-based diets. We speculated that improvements in performance with AH addition to CS-based diets could be due to differences in mineral and DCAD concentrations between the 2 forages. The objective of this experiment was to test the effects of forage (CS vs. AH) and mineral supplementation on production responses using 45 lactating Holstein cows during the first 20 wk postpartum. Dietary treatments included (1) 50:50 mixture of AH and CS as the forage (AHCS); (2) CS as the sole forage; and (3) CS fortified with mineral supplements (CaCO(3) and K(2)CO(3)) to match the Ca and K content of the AHCS diet (CS-DCAD). Feed intake and milk production were equivalent or greater for cows fed the CS and CS-DCAD diets compared with those fed the AHCS diet. Fat percentage was greater in cows fed the CS compared with the AHCS diet. Fat-corrected milk (FCM; 3.5%) tended to be greater in cows fed the CS and CS-DCAD diets compared with the AHCS diet. Feed efficiencies measured as FCM/dry matter intake were 1.76, 1.80, and 1.94 for the AHCS, CS, and CS-DCAD diets, respectively. The combined effects of reduced feed intake and increased FCM contributed to increased feed efficiency with the CS-DCAD diet, which contained 1.41% K compared with 1.18% K in the CS diet, and we speculate that this might be the result of added dietary K and DCAD effects on digestive efficiency. These results indicate no advantage to including AH in CS-based diets, but suggest that improving mineral supplementation in CS-based diets may increase feed efficiency.

A fecal test for assessing phosphorus overfeeding on dairy farms: evaluation using extensive farm data.

Managing P on dairy farms requires the assessment and monitoring of P status of the animals so that potential overfeeding may be minimized. Numerous published studies have demonstrated that for lactating dairy cows, increasing P concentrations in diets led to greater P excretion in feces. More recent work reported that inorganic P (P(i)) in 0.1% HCl extracts of feces (fecal extract P(i), g/kg) closely reflects dietary P changes. This has led to the proposal that 0.1% HCl fecal extract P(i) may serve as an indicator of the animal's P status (adequate or excessive) when compared with a benchmark value. Here, we present the results of an extensive evaluation of the proposed fecal P indicator test. With samples (n=575) from >90 farms, fecal total P (TP, g/kg) and fecal extract P were positively correlated with dietary P (X, g/kg): TP=1.92X - 0.17 (R2=0.36); fecal extract P=1.82X - 2.54 (R2=0.46). Fecal extract P was responsive to dietary P changes, whereas the remaining P, calculated as TP minus fecal extract P, was not. A provisional benchmark value of fecal extract P representing near-adequate P status was set at 4.75g/kg. Assessment of the farm data using the benchmark indicated that 316 out of 575 data points were associated with possible P overfeeding. Advantages of the fecal-based test over feed-based analysis to assess P status are discussed. The fecal extract P method is a simple and practical test that can be used as an assessment tool for helping dairy producers improve P management and reduce their environmental footprint.

qSOFA as a predictor of ICU outcomes in a resource-limited setting in KwaZulu-Natal Province, South Africa.

Background: Sepsis is a major cause of morbidity and mortality, especially in critical care patients. Developing tools to identify patients who are at risk of poor outcomes and prolonged length of stay in intensive care units (ICUs) is critical, particularly in resource-limited settings. Objectives: To determine whether the quick sequential organ failure assessment (qSOFA) score based on bedside assessment alone was a promising tool for risk prediction in low-resource settings. Methods: A retrospective cohort of adult patients admitted to the intensive care unit (ICU) at Edendale Hospital in Pietermaritzburg, South Africa (SA), was recruited into the study between 2014 and 2018. The association of qSOFA with in-ICU mortality was measured using multivariable logistic regression. Discrimination was assessed using the area under the receiver operating characteristic curve and the additive contribution to a baseline model using likelihood ratio testing. Results: The qSOFA scores of 0, 1 and 2 were not associated with increased odds of in-ICU mortality (adjusted odds ratio (aOR) 1.24, 95% confidence interval (CI) 0.86 - 1.79; p=0.26) in patients with infection, while the qSOFA of 3 was associated with in-ICU mortality in infected patients (aOR 2.82; 95% CI 1.91 - 4.16; p<0.001). On the other hand, the qSOFA scores of 2 (aOR 3.25; 95% CI 1.91 - 5.53; p<0.001) and 3 (aOR 6.26, 95% CI 0.38 - 11.62, p<0.001) were associated with increased odds of in-ICU mortality in patients without infection. Discrimination for mortality was fair to poor and adding qSOFA to a baseline model yielded a statistical improvement in both cases (p<0.001). Conclusion: qSOFA was associated with, but weakly discriminant, for in-ICU mortality for patients with and without infection in a resource-limited, public hospital in SA. These findings add to the growing body of evidence that support the use of qSOFA to deliver low-cost, high-value critical care in resource-limited settings. Contributions of the study: This study expanded the data supporting the use of qSOFA in resource-limited settings beyond the emergency department or ward to include patients admitted to the ICU. Additionally, this study demonstrated stronger predictive abilities in a population of patients admitted with trauma without suspected or confirmed infection, thus providing an additional use of qSOFA as a risk-prediction tool for a broader population.

Modeling nutrient fluxes and plasma ketone bodies in periparturient cows.

A mechanistic model was developed to study the interrelationship between glucose and lipid metabolism in periparturient cows. The driving variables were dry matter intake, feed composition, calf birth weight, milk production, and milk components. The response variables were body fat content and concentrations of plasma glucose, glycerol, nonesterified fatty acids (NEFA), and total ketone bodies (KB). Fetal growth and milk synthesis were assigned the highest priority for glucose demand in the model. The rate of fat mobilization was expressed as a function of glucose deficiency. The model assumed first-order kinetics for utilization of NEFA and KB. Model prediction errors were 19, 43, 48, and 36% of mean predictions for glucose, glycerol, NEFA, and KB, respectively. A linear bias was observed in KB and glycerol predictions. The model may be useful for understanding and explaining ketosis development.

Evaluation of a mechanistic model of glucose and lipid metabolism in periparturient cows.

A mechanistic model was previously developed to quantitatively describe glucose and lipid metabolism in periparturient cows. The objectives of the current study were to evaluate the accuracy and precision of the model by comparing predictions to data collected in an independent experiment; to identify the critical metabolic processes for ketosis development; and to use the model to evaluate the relative importance of dry matter intake, calf birth weight, milk yield, and body condition score on nutrition management. Residuals (observed - predicted) were regressed on model predictions using the independent data for the model inputs, and prediction error was calculated. Each model parameter (e.g., the rate of glucose consumption by peripheral tissues) was increased independently by 1 standard deviation to identify the critical metabolic processes for ketosis development. Critical control points to prevent ketosis were identified by increasing the driving variables of the model by 1 standard deviation to estimate the response in ketone body formation. The root mean square prediction error was 0.527 mM for ketone body predictions. The sensitivity analysis indicated that in the first few days of lactation, the rate of nonesterified fatty acid utilization had a greater effect on ketone body concentrations in periparturient cows than the other parameters tested in the model. The model was consistent with the knowledge that over-fattening during the prepartum period should be avoided to help prevent ketosis.

Test of conditions that affect in vitro production of volatile fatty acids and gases.

In vitro methods have been developed to measure digestibility, but such methods may not accurately reflect gas production or volatile fatty acid (VFA) profiles. The objective of this study was to determine the effect of different in vitro conditions on VFA and gas production. The experimental design was a 4 × 2 × 2 factorial CRD with four replicates. Treatments were four ratios of medium to rumen fluid by volume (5:95, 25:75, 50:50, and 75:25), two concentrations (w/v) of added timothy hay (0.5% or 1%), with or without added sodium acetate (increased initial concentration by 50 mM). Total volume of medium and rumen fluid was 10 mL per tube. Measurements of gas production and VFA were recorded at 0, 4, 16, 24, and 48 h. Statistical analyses used a mixed model including all fixed effects and interactions with tube as a random effect, and time nested within tube. Total gas production increased (P < 0.001) with higher medium proportion. The final pH increased (P < 0.0001) as medium proportion increased. Medium proportion positively affected (P < 0.05) overall average concentration of both acetate production and propionate production. Higher hay concentration increased (P < 0.0001) total gas produced from 0 to 48 h, increased total acetate production (P < 0.01), propionate production (P < 0.001), and decreased pH between 24 and 48 h (P < 0.0001). Sodium acetate addition increased (P < 0.0001) pH between 24 and 48 h. Acetate:propionate (A:P) concentration decreased over time (P < 0.0001). Initial rumen fluid A:P ratio was 3.7 but average A:P ratio of produced VFA started at 2.2 and increased to 2.50 (SE = ±0.51). The A:P ratio differed for VFA produced in vitro compared to initial rumen fluid, but no tested treatments were found to change A:P ratio.

Glucosylation of human collagen in aging and diabetes mellitus.

Several of the characteristic complications of diabetes mellitus resemble age-like changes in collagen-rich tissues. It has been reported that increased glucosylation of hemoglobin and serum proteins occurs in diabetes. Glucosylation of insoluble human tendon collagen, a protein with little or no turnover was determined by a thiobarbituric acid method in 23 subjects as a function of age and the presence or absence of diabetes. Amounts of glucose and collagen solubilized by collagenase digestion of the samples were also determined. Glucosylation of collagen was found to increase with age and was markedly increased in juvenile onset diabetes. There appeared to be a limit to the amount of glucosylation that could occur, and older individuals with maturity-onset diabetes demonstrated glucosylation within that limit. The glucose nonenzymatically bound to human collagen may indicate the level of long-term control of the diabetes, and may play a role in the alteration of collagenous tissue properties that occurs in both aging and diabetes.

Effects of age and diabetes mellitus on the solubility and nonenzymatic glucosylation of human skin collagen.

Collagen from human skin was fractionated into neutral salt-soluble, acid-soluble, pepsin-released, and insoluble fractions. No age-related changes were observed in the proportion of collagen extracted by neutral salt. A significant age-related decrease in the proportion of acid-soluble collagen was found. A highly significant (P less than 0.001) age-related decrease in the amount of collagen released by pepsin digestion was observed, with a concomitant age-related increase in the fraction of insoluble collagen. The amount of ketoamine-linked glucose bound to this insoluble collagen also increased significantly with age. Skin collagen from three juvenile onset diabetics (JOD) and one young maturity onset diabetic (MOD) appeared to have undergone accelerated aging. JOD and the young MOD had significantly less collagen released by pepsin digestion and significantly more insoluble collagen than would be predicted by their ages. The collagen released by pepsin digestion of the diabetic samples had more high molecular weight components than similar fractions obtained from age-matched nondiabetic controls. There was also more ketoamine-linked glucose bound to the insoluble collagen of JOD than to that fraction from comparably aged control subjects. The apparent acceleration of collagen aging in diabetes mellitus may play a role in complications of diabetes that occur in collagen-rich tissues.

Effect of a transition diet on production performance and metabolism in periparturient dairy cows.

The objectives of this study were to characterize the change in blood metabolites over time, and to evaluate the effect of dietary energy concentration on ketone body accumulation in periparturient cows. Twenty-eight multiparous Holstein cows were listed in order of their anticipated due dates and assigned randomly to 1 of 2 groups: with or without a transition diet. The control group received a nonlactating cow diet [1.54 Mcal/kg of net energy for lactation (NE(L)), 10.9% crude protein (CP), 53.1% neutral detergent fiber (NDF)] from 28 d before expected parturition, and a lactation diet (1.77 Mcal of NE(L)/kg, 16.8% CP, 29.9% NDF) after parturition. The treatment group received a transition diet (1.71 Mcal of NE(L)/kg, 16.8% CP, 35.2% NDF) from 17 d before parturition to 14 d after calving and was fed the same diets as cows in the control group during the third week of lactation. Blood from the coccygeal vein was sampled 3 times per week from 21 d before expected parturition to 21 d postpartum for analysis of glucose, nonesterified fatty acids (NEFA), beta-hydroxybutyrate, acetoacetate, acetone, and glycerol. There were no significant differences in dry matter intake, milk yield, milk components, body weight change, and body condition score change during the postcalving period. Plasma concentrations of different ketone bodies changed in parallel, stayed relatively constant precalving, peaked after parturition, and then decreased but remained high compared with concentrations late in gestation. Plasma concentrations of NEFA and glycerol changed in a pattern similar to those of the ketone bodies. Feeding a transition diet resulted in a greater area under the curve (AUC) for glucose in the last 17 d of gestation, but in no effect within the first 21 d in milk. Acetoacetate AUC was greater for treatment cows than for control cows across the first 21 d in milk. The AUC of NEFA and glycerol between d 15 and 21 postpartum were greater for treatment cows than for control cows. Feeding a transition diet both before and after parturition was associated with greater mobilization of adipose tissue and greater exposure to ketone bodies in early lactation compared with abruptly changing to a lactation diet after parturition.

Expression of multiple UNC-13 proteins in the Caenorhabditis elegans nervous system.

The Caenorhabditis elegans UNC-13 protein and its mammalian homologues are important for normal neurotransmitter release. We have identified a set of transcripts from the unc-13 locus in C. elegans resulting from alternative splicing and apparent alternative promoters. These transcripts encode proteins that are identical in their C-terminal regions but that vary in their N-terminal regions. The most abundant protein form is localized to most or all synapses. We have analyzed the sequence alterations, immunostaining patterns, and behavioral phenotypes of 31 independent unc-13 alleles. Many of these mutations are transcript-specific; their phenotypes suggest that the different UNC-13 forms have different cellular functions. We have also isolated a deletion allele that is predicted to disrupt all UNC-13 protein products; animals homozygous for this null allele are able to complete embryogenesis and hatch, but they die as paralyzed first-stage larvae. Transgenic expression of the entire gene rescues the behavior of mutants fully; transgenic overexpression of one of the transcripts can partially compensate for the genetic loss of another. This finding suggests some degree of functional overlap of the different protein products.

Milk production of dairy cows fed differing concentrations of rumen-degraded protein.

Thirty-two multiparous and 16 primiparous Holstein cows in midlactation averaging 126 d in milk were used to determine the effects of rumen-degraded protein (RDP) concentration on lactation performance. Cows were assigned to diets in a repeated Latin square design with 3-wk experimental periods. Diets were formulated to provide 4 concentrations of dietary RDP [6.8, 8.2, 9.6, and 11.0% of dry matter (DM)] while rumen-undegraded protein remained constant (5.8% of DM). Diets contained 50% corn silage and 50% concentrate (DM basis). Ingredients within diets were equal across treatments except for ground corn, soybean meal, and ruminally protected soybean meal. Dry matter intake was not affected by treatment. Milk yield, fat yield, and protein yield all increased linearly when cows were fed diets with greater RDP. Milk fat and protein concentration each increased by 0.16 percentage units for cows fed 11% RDP compared with 6.8% RDP. Milk protein yield increased by 0.19 g/d for every 1 g/d increase in crude protein supplied mainly as RDP. As RDP increased, the efficiency of N use declined linearly. Milk urea N increased linearly when cows were fed increasing amounts of RDP, indicating increased losses of N via urine. Feeding deficient RDP diets to dairy cows can decrease nitrogen excretion, but it also decreases lactation performance. These data show an environmental benefit from underfeeding RDP to dairy cows according to National Research Council requirements, but at a financial cost to the dairy producer.

Collagen aging in vitro by nonenzymatic glycosylation and browning.

Aging and diabetes mellitus are associated with cross-linking and nonenzymatic glycosylation of collagen. Incubation of tendon fibers with reducing sugars results in increased breaking time in urea similar to that seen in aging, and in nonenzymatic glycosylation and browning. Effect of a sugar is proportional to the amount of sugar available in the open chain form. The increase in breaking time correlates with the appearance of chromophores characteristic of crosslinked browning products. Collagen altered by nonenzymatic browning may play a role in some age-like major complications of diabetes.

Apparent accelerated aging of human collagen in diabetes mellitus.

The chronologic ages of human subjects were determined experimentally by enzymatic digestion of tendon collagen samples. Determined age closely matched actual age for individuals dying with a variety of major diseases. Juvenile diabetics did not fit this pattern; their experimentally determined ages were significantly greater than their actual ages. This raises the possibility of relationships between diabetes mellitus, changes in connective tissue, and accelerated aging.

Relation of neurohumoral activation to clinical variables and degree of ventricular dysfunction: a report from the Registry of Studies of Left Ventricular Dysfunction. SOLVD Investigators.

OBJECTIVES: This study examined the relation between neurohumoral activation and severity of left ventricular dysfunction and congestive heart failure in a broad group of patients with depressed left ventricular function who were not recruited on the basis of eligibility for a therapeutic trial. BACKGROUND: Previous studies have established the presence of neurohumoral activation in patients with severe congestive heart failure. It is not known whether the activation of these neurohumoral mechanisms is related to an impairment in left ventricular function. METHODS: From the 6,273 patients recruited into the Studies of Left Ventricular Dysfunction Registry (SOLVD), a subgroup of 859 patients were randomly selected, and their plasma norepinephrine, plasma renin activity, arginine vasopressin and atrial natriuretic peptide levels were correlated with clinical findings, New York Heart Association functional class, left ventricular ejection fraction and drug use. RESULTS: There was a weak but significant correlation between ejection fraction and an increase in plasma norepinephrine (rho = -0.18, p < 0.0001), plasma renin activity (rho = -0.24, p < 0.0001) and arginine vasopressin (rho = -0.12, p < 0.003). The only exception was atrial natriuretic peptide, which showed the best correlation to ejection fraction (rho = -0.37, p < 0.0001). Deterioration in functional class was associated more with increases in atrial natriuretic peptide (p = 0.0003) and plasma renin activity (p = 0.0003) and less with an increase in plasma norepinephrine. Of the clinical variables, elevated jugular venous pressure and third heart sound (S3) gallop were significantly associated with increased levels of plasma norepinephrine, plasma renin activity and atrial natriuretic peptide. We then compared the relation of neurohormones with clinical signs, functional status, ejection fraction and drug therapy and controlled for mutual interactive effects. After adjustment, a decrease in ejection fraction was still significantly related to an increase in plasma norepinephrine, plasma renin activity and atrial natriuretic peptide. In contrast, only a difference between functional classes I and III/IV was associated with an increase in plasma renin activity and atrial natriuretic peptide levels. CONCLUSIONS: Neurohumoral activation in patients with heart failure is related to severity of left ventricular functional depression, and this relation is independent of functional class or concomitant drug therapy.

Syphilis, chlamydia, and gonorrhea screening in HIV-infected patients in primary care, San Francisco, California, 2003.

The Centers for Disease Control (CDC) recommends sexually transmitted disease (STD) screening among HIV-infected persons in order to reduce HIV transmission. We evaluated the results of routine screening for syphilis and for urogenital, pharyngeal, and rectal gonorrhea (GC) and chlamydia (CT) among asymptomatic HIV-infected patients at an HIV primary care clinic in San Francisco, California. We found 15 new syphilis infections of 814 tested (1.8%) and 60 new cases of CT or GC infection of 586 tested (10.2%), with 88% of GC and CT infections occurring at nonurethral sites. Our study reveals a high rate of asymptomatic STDs among HIV-infected patients in primary care and supports the CDC recommendations to screen HIV-infected patients for STDs at all relevant anatomic sites.

Vulnerability of Jews to affective disorders.

OBJECTIVE: Psychiatric literature over the past 100 years suggests that Jews are at higher risk for affective disorders than numbers of other religious groups. To examine these claims, the authors analyzed data from the National Institute of Mental Health Epidemiologic Catchment Area (ECA) study. In addition, the relationships among gender, alcoholism, and major depression were investigated. METHOD: The period prevalence and lifetime rates of DSM-III major depression among Jews, Catholics, Protestants, individuals in other religious groups, and individuals with no religious affiliation were examined in the Los Angeles and New Haven, Conn., ECA data. Logistic regression with covariates for site, gender, marital status, and socioeconomic status was used to estimate odds ratios and 95% confidence intervals. The calculated rates, based on the combined data from ECA study waves 1 and 2 for the white population, were weighted according to the 1980 U.S. population census. Female-to-male rate ratios and rates of alcohol abuse/dependence were also obtained. RESULTS: While no differences were found among females, Jewish males had significantly higher rates of major depression than Catholics, Protestants, and all non-Jews combined. Jews had a 1:1 female-to-male ratio for major depression, in contrast to the other religious groups, which approached the universal 2:1 ratio. Rates of alcohol abuse/dependence were inversely related to rates of major depression. CONCLUSIONS: The results support only in part the earlier reports that Jews have higher rates of depression. The equal gender distribution of major depression among Jews may be associated with the lower rate of alcoholism among Jewish males.