The STR/ort mouse model of spontaneous osteoarthritis - an update.

Osteoarthritis is a degenerative joint disease and a world-wide healthcare burden. Characterized by cartilage degradation, subchondral bone thickening and osteophyte formation, osteoarthritis inflicts much pain and suffering, for which there are currently no disease-modifying treatments available. Mouse models of osteoarthritis are proving critical in advancing our understanding of the underpinning molecular mechanisms. The STR/ort mouse is a well-recognized model which develops a natural form of osteoarthritis very similar to the human disease. In this Review we discuss the use of the STR/ort mouse in understanding this multifactorial disease with an emphasis on recent advances in its genetics and its bone, endochondral and immune phenotypes.

Haemagglutinin mutations and glycosylation changes shaped the 2012/13 influenza A(H3N2) epidemic, Houston, Texas.

While the early start and higher intensity of the 2012/13 influenza A virus (IAV) epidemic was not unprecedented, it was the first IAV epidemic season since the 2009 H1N1 influenza pandemic where the H3N2 subtype predominated. We directly sequenced the genomes of 154 H3N2 clinical specimens collected throughout the epidemic to better understand the evolution of H3N2 strains and to inform the H3N2 vaccine selection process. Phylogenetic analyses indicated that multiple co-circulating clades and continual antigenic drift in the haemagglutinin (HA) of clades 5, 3A, and 3C, with the evolution of a new 3C subgroup (3C-2012/13), were the driving causes of the epidemic. Drift variants contained HA substitutions and alterations in the potential N-linked glycosylation sites of HA. Antigenic analysis demonstrated that viruses in the emerging subclade 3C.3 and subgroup 3C-2012/13 were not well inhibited by antisera generated against the 3C.1 vaccine strains used for the 2012/13 (A/Victoria/361/2011) or 2013/14 (A/Texas/50/2012) seasons. Our data support updating the H3N2 vaccine strain to a clade 3C.2 or 3C.3-like strain or a subclade that has drifted further. They also underscore the challenges in vaccine strain selection, particularly regarding HA and neuraminidase substitutions derived during laboratory passage that may alter antigenic testing accuracy.

Genomic analysis of pandemic and post-pandemic influenza A pH1N1 viruses isolated in Rio Grande do Sul, Brazil.

During the 2009 influenza A pH1N1 pandemics in Brazil, the state that was most affected was Rio Grande do Sul (RS), with over 3,000 confirmed cases, including 298 deaths. While no cases were confirmed in 2010, 103 infections with 14 deaths by pH1N1 were reported in 2011. Genomic analysis of the circulating viruses is fundamental for understanding viral evolution and supporting vaccine development against these pathogens. This study investigated whole genomes of six pH1N1 virus isolates from pandemic and post-pandemic periods in RS, Brazil. Phylogenetic analysis using the concatenated genome segments demonstrated that at least two lineages of the virus co-circulated in RS during the 2009 pandemic period. Moreover, our analysis showed that the post-pandemic pH1N1 virus from 2011 constitutes a distinct clade whose ancestor belongs to clade 7. All six isolates contained amino acid substitutions in their proteins when compared to the archetype strains California/04/2009 and California/07/2009. The 2011 isolates contained more amino acid substitutions, and most of their genes were under purifying selection. Based on the amino acid substitutions in HA epitopes from strains isolated in RS, Brazil, in silico analysis predicted a decrease in vaccine efficacy against post-pandemic strains (median 31.562 %) in relation to pandemic ones (median 39.735 %).

Predictors of bacterial pneumonia in Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT).

BACKGROUND AND OBJECTIVES: Bacterial pneumonia still contributes to morbidity/mortality in HIV infection despite effective combination antiretroviral therapy (cART). Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT), a trial of intermittent recombinant interleukin-2 (rIL-2) with cART vs. cART alone (control arm) in HIV-infected adults with CD4 counts ≥300cells/µL, offered the opportunity to explore associations between bacterial pneumonia and rIL-2, a cytokine that increases the risk of some bacterial infections. METHODS: Baseline and time-updated factors associated with first-episode pneumonia on study were analysed using multivariate proportional hazards regression models. Information on smoking/pneumococcal vaccination history was not collected. RESULTS: IL-2 cycling was most intense in years 1-2. Over ≈7 years, 93 IL-2 [rate 0.67/100 person-years (PY)] and 86 control (rate 0.63/100 PY) patients experienced a pneumonia event [hazard ratio (HR) 1.06; 95% confidence interval (CI) 0.79, 1.42; P=0.68]. Median CD4 counts prior to pneumonia were 570cells/µL (IL-2 arm) and 463cells/µL (control arm). Baseline risks for bacterial pneumonia included older age, injecting drug use, detectable HIV viral load (VL) and previous recurrent pneumonia; Asian ethnicity was associated with decreased risk. Higher proximal VL (HR for 1 log(10) higher VL 1.28; 95% CI 1.11, 1.47; P<0.001) was associated with increased risk; higher CD4 count prior to the event (HR per 100 cells/µL higher 0.94; 95% CI 0.89, 1.0; P=0.04) decreased risk. Compared with controls, the hazard for a pneumonia event was higher if rIL-2 was received <180 days previously (HR 1.66; 95% CI 1.07, 2.60; P=0.02) vs.≥180 days previously (HR 0.98; 95% CI 0.70, 1.37; P=0.9). Compared with the control group, pneumonia risk in the IL-2 arm decreased over time, with HRs of 1.41, 1.71, 1.16, 0.62 and 0.84 in years 1, 2, 3-4, 5-6 and 7, respectively. CONCLUSIONS: Bacterial pneumonia rates in cART-treated adults with moderate immunodeficiency are high. The mechanism of the association between bacterial pneumonia and recent IL-2 receipt and/or detectable HIV viraemia warrants further exploration.

Interleukin-2 therapy in patients with HIV infection.

BACKGROUND: Used in combination with antiretroviral therapy, subcutaneous recombinant interleukin-2 raises CD4+ cell counts more than does antiretroviral therapy alone. The clinical implication of these increases is not known. METHODS: We conducted two trials: the Subcutaneous Recombinant, Human Interleukin-2 in HIV-Infected Patients with Low CD4+ Counts under Active Antiretroviral Therapy (SILCAAT) study and the Evaluation of Subcutaneous Proleukin in a Randomized International Trial (ESPRIT). In each, patients infected with the human immunodeficiency virus (HIV) who had CD4+ cell counts of either 50 to 299 per cubic millimeter (SILCAAT) or 300 or more per cubic millimeter (ESPRIT) were randomly assigned to receive interleukin-2 plus antiretroviral therapy or antiretroviral therapy alone. The interleukin-2 regimen consisted of cycles of 5 consecutive days each, administered at 8-week intervals. The SILCAAT study involved six cycles and a dose of 4.5 million IU of interleukin-2 twice daily; ESPRIT involved three cycles and a dose of 7.5 million IU twice daily. Additional cycles were recommended to maintain the CD4+ cell count above predefined target levels. The primary end point of both studies was opportunistic disease or death from any cause. RESULTS: In the SILCAAT study, 1695 patients (849 receiving interleukin-2 plus antiretroviral therapy and 846 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 202 cells per cubic millimeter were enrolled; in ESPRIT, 4111 patients (2071 receiving interleukin-2 plus antiretroviral therapy and 2040 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 457 cells per cubic millimeter were enrolled. Over a median follow-up period of 7 to 8 years, the CD4+ cell count was higher in the interleukin-2 group than in the group receiving antiretroviral therapy alone--by 53 and 159 cells per cubic millimeter, on average, in the SILCAAT study and ESPRIT, respectively. Hazard ratios for opportunistic disease or death from any cause with interleukin-2 plus antiretroviral therapy (vs. antiretroviral therapy alone) were 0.91 (95% confidence interval [CI], 0.70 to 1.18; P=0.47) in the SILCAAT study and 0.94 (95% CI, 0.75 to 1.16; P=0.55) in ESPRIT. The hazard ratios for death from any cause and for grade 4 clinical events were 1.06 (P=0.73) and 1.10 (P=0.35), respectively, in the SILCAAT study and 0.90 (P=0.42) and 1.23 (P=0.003), respectively, in ESPRIT. CONCLUSIONS: Despite a substantial and sustained increase in the CD4+ cell count, as compared with antiretroviral therapy alone, interleukin-2 plus antiretroviral therapy yielded no clinical benefit in either study. (ClinicalTrials.gov numbers, NCT00004978 [ESPRIT] and NCT00013611 [SILCAAT study].)

Molecular determinants of species specificity in the coronavirus receptor aminopeptidase N (CD13): influence of N-linked glycosylation.

Aminopeptidase N (APN), a 150-kDa metalloprotease also called CD13, serves as a receptor for serologically related coronaviruses of humans (human coronavirus 229E [HCoV-229E]), pigs, and cats. These virus-receptor interactions can be highly species specific; for example, the human coronavirus can use human APN (hAPN) but not porcine APN (pAPN) as its cellular receptor, and porcine coronaviruses can use pAPN but not hAPN. Substitution of pAPN amino acids 283 to 290 into hAPN for the corresponding amino acids 288 to 295 introduced an N-glycosylation sequon at amino acids 291 to 293 that blocked HCoV-229E receptor activity of hAPN. Substitution of two amino acids that inserted an N-glycosylation site at amino acid 291 also resulted in a mutant hAPN that lacked receptor activity because it failed to bind HCoV-229E. Single amino acid revertants that removed this sequon at amino acids 291 to 293 but had one or five pAPN amino acid substitution(s) in this region all regained HCoV-229E binding and receptor activities. To determine if other N-linked glycosylation differences between hAPN, feline APN (fAPN), and pAPN account for receptor specificity of pig and cat coronaviruses, a mutant hAPN protein that, like fAPN and pAPN, lacked a glycosylation sequon at 818 to 820 was studied. This sequon is within the region that determines receptor activity for porcine and feline coronaviruses. Mutant hAPN lacking the sequon at amino acids 818 to 820 maintained HCoV-229E receptor activity but did not gain receptor activity for porcine or feline coronaviruses. Thus, certain differences in glycosylation between coronavirus receptors from different species are critical determinants in the species specificity of infection.

The role of househusband and housewife as perceived by a college population.

The research literature frequently conveys the notion that gender roles are becoming less stereotypical. In this study the authors explored the question of how a college population views the role of househusband and housewife and if there are significant differences in role expectations. A 51-item questionnaire was constructed and administered to 526 college students. This sample was chosen because college students are likely to be assuming these roles in the near future. As predicted, the role expectations for househusbands and housewives are not the same. Women tended to question the current structure of household roles more than did men, and the role of househusband was generally more negatively perceived. Reasons for these findings are discussed.

Adjunctive antibiotic/anticoagulant lock therapy in the treatment of bacteremia associated with the use of a subcutaneously implanted hemodialysis access device.

To improve vascular access for hemodialysis, a new device (Dialock Hemodialysis Access System, Biolink Corporation, Middleboro, MA) has been developed. Implanted subcutaneously, the device is accessed by percutaneous puncture. Attached to the device are two catheters that are implanted into the superior vena cava or right atrium. Clinical results thus far have been promising. However, use of this device is not free from infectious complications. In the present pilot study, 25 maintenance hemodialysis patients were implanted with 26 Dialock devices. The incidence of bacteremia was 2.9/1,000 catheter days. In 14 episodes of bacteremia in 8 patients the infection was successfully treated with a combination of systemic antibiotic treatment and adjunctive antibiotic/anticoagulant lock therapy. The lock therapy entailed the instillation of both an antibiotic and an anticoagulant into the device. We believe that the antibiotic/anticoagulant lock technique is an effective, adjunctive therapeutic modality in the treatment of infections related to the use of indwelling vascular access devices.

A randomized study of antiretroviral management based on plasma genotypic antiretroviral resistance testing in patients failing therapy. CPCRA 046 Study Team for the Terry Beirn Community Programs for Clinical Research on AIDS.

OBJECTIVE: To determine the short-term effects of using genotypic antiretroviral resistance testing (GART) with expert advice in the management of patients failing on a protease inhibitor and two nucleoside reverse transcriptase inhibitors. DESIGN: Prospective randomized controlled trial. SETTING: Multicenter community-based clinical trials network. PATIENTS: One-hundred and fifty-three HIV-infected adults with a threefold or greater rise in plasma HIV-1 RNA on at least 16 weeks of combination antiretroviral therapy. INTERVENTIONS: Randomization was either to a GART group, where genotype interpretation and suggested regimens were provided to clinicians, or to a no-GART group, where treatment choices were made without such input. MAIN OUTCOMES MEASURES: Plasma HIV-1 RNA levels and CD4 cell counts were measured at 4, 8, and 12 weeks following randomization. The primary endpoint was change in HIV-1 RNA levels from baseline to the average of the 4 and 8 week levels. RESULTS: The average baseline CD4 cell count was 230 x 10(6) cells/l and the median HIV-1 RNA was 28,085 copies/ml. At entry, 82 patients were failing on regimens containing indinavir, 51 on nelfinavir, 11 on ritonavir, and nine on saquinavir. HIV-1 RNA, averaged at 4 and 8 weeks, decreased by 1.19 log10 for the 78 GART patients and -0.61 log10 for the 75 no-GART patients (treatment difference: -0.53 log, 95% confidence interval, -0.77 to -0.29; P = 0.00001). Overall, the best virologic responses occurred in patients who received three or more drugs to which their HIV-1 appeared to be susceptible. CONCLUSION: In patients failing triple drug therapy, GART with expert advice was superior to no-GART as measured by short-term viral load responses.

Frequency of antiretroviral drug resistance mutations in HIV-1 strains from patients failing triple drug regimens. The Terry Beirn Community Programs for Clinical Research on AIDS.

The frequency of protease and reverse transcriptase (RT) gene mutations was determined in HIV-1 strains from 153 patients entering the CPCRA 046 (GART) study who were failing triple-drug regimens consisting of one protease inhibitor (PI) and two RT inhibitors. Population-based sequence analyses showed that nearly all patients had similar RT gene mutations regardless of prior drug exposure, although the M184V mutation was significantly less prevalent in patients not recently treated with lamivudine. Whilst typical inhibitor-specific ('signature') protease gene mutations were found in patients failing their first PI, these mutations were significantly less likely to be found in patients exposed to two or more PIs. Protease gene mutations associated with multi-PI resistance were more likely to be observed in patients treated with more than one PI. These results suggest sequential treatment with PIs select for a relatively limited number of protease gene mutations that likely originated during early PI therapy. These protease gene mutations and a similarly limited set of RT gene mutations appear to be responsible for treatment failure in antiretroviral therapy.

Can emergency department physicians safely and effectively initiate thrombolysis for acute ischemic stroke?

OBJECTIVE: To review the clinical outcomes of stroke patients treated with IV tissue plasminogen activator (tPA; alteplase) in a community setting and to compare outcomes when treatment was initiated by a neurologist or an emergency department (ED) physician in telephone consultation with a neurologist and radiologist. METHODS: Clinical information was prospectively collected for 43 stroke patients treated with IV tPA (alteplase) within a five-hospital network of affiliated community hospitals. Blinded 3-month outcomes were obtained with telephone interview or patient visit. RESULTS: Excellent functional recovery measured by a Modified Rankin score of 0 to 1 (42%), symptomatic intracerebral hemorrhages (7%), and mortality (16.3%) were similar to those reported by National Institute of Neurological Disorders and Stroke (39%, 7.7%, 17.3%). After initial screening by an ED physician, 20 patients were directly examined by a stroke neurologist who then prescribed tPA. Twenty-three patients received tPA prescribed by an ED physician after telephone consultation with a neurologist and review of the head CT by a radiologist. Functional outcome, symptomatic intracerebral bleeding rate, and mortality rate were similar between these groups. Door-to-needle time was similar. Protocol deviations were much higher when ED physicians prescribed the tPA compared to when neurologists did (30% versus 5%). These protocol deviations were reduced with staff education. CONCLUSIONS: The clinical results of the National Institute of Neurological Disorders and Stroke tPA Stroke Trial were replicated in this small series of patients treated in a community setting. Outcomes were similar whether the prescribing physician was a neurologist or an ED physician.

Low risk-factor profile and long-term cardiovascular and noncardiovascular mortality and life expectancy: findings for 5 large cohorts of young adult and middle-aged men and women.

CONTEXT: Three major coronary risk factors-serum cholesterol level, blood pressure, and smoking-increase incidence of coronary heart disease (CHD) and related end points. In previous investigations, risks for low-risk reference groups were estimated statistically because samples contained too few such people to measure risk. OBJECTIVE: To measure long-term mortality rates for individuals with favorable levels for all 3 major risk factors, compared with others. DESIGN: Two prospective studies, involving 5 cohorts based on age and sex, that enrolled persons with a range of risk factors. Low risk was defined as serum cholesterol level less than 5.17 mmol/L (<200 mg/dL), blood pressure less than orequal to 120/80 mm Hg, and no current cigarette smoking. All persons with a history of diabetes, myocardial infarction (MI), or, in 3 of 5 cohorts, electrocardiogram (ECG) abnormalities, were excluded. SETTING AND PARTICIPANTS: In 18 US cities, a total of 72144 men aged 35 through 39 years and 270671 men aged 40 through 57 years screened (1973-1975) for the Multiple Risk Factor Intervention Trial (MRFIT); in Chicago, a total of 10025 men aged 18 through 39 years, 7490 men aged 40 through 59 years, and 6229 women aged 40 through 59 years screened (1967-1973) for the Chicago Heart Association Detection Project in Industry (CHA) (N = 366559). MAIN OUTCOME MEASURES: Cause-specific mortality during 16 (MRFIT) and 22 (CHA) years, relative risks (RRs) of death, and estimated greater life expectancy, comparing low-risk subcohorts vs others by age strata. RESULTS: Low-risk persons comprised only 4.8% to 9.9% of the cohorts. All 5 low-risk groups experienced significantly and markedly lower CHD and cardiovascular disease death rates than those who had elevated cholesterol level, or blood pressure, or smoked. For example, age-adjusted RRs of CHD mortality ranged from 0.08 for CHA men aged 18 to 39 years to 0.23 for CHA men aged 40 through 59 years. The age-adjusted relative risks (RRs) for all cardiovascular disease mortality ranged from 0.15 for MRFIT men aged 35 through 39 years to 0.28 for CHA men aged 40 through 59 years. The age-adjusted RR for all-cause mortality rate ranged from 0.42 for CHA men aged 40 through 59 years to 0.60 for CHA women aged 40 through 59 years. Estimated greater life expectancy for low-risk groups ranged from 5.8 years for CHA women aged 40 through 59 years to 9.5 years for CHA men aged 18 through 39 years. CONCLUSIONS: Based on these very large cohort studies, for individuals with favorable levels of cholesterol and blood pressure who do not smoke and do not have diabetes, MI, or ECG abnormalities, long-term mortality is much lower and longevity is much greater. A substantial increase in the proportion of the population at lifetime low risk could contribute decisively to ending the CHD epidemic.

Acupuncture and amitriptyline for pain due to HIV-related peripheral neuropathy: a randomized controlled trial. Terry Beirn Community Programs for Clinical Research on AIDS.

CONTEXT: Peripheral neuropathy is common in persons infected with the human immunodeficiency virus (HIV) but few data on symptomatic treatment are available. OBJECTIVE: To evaluate the efficacy of a standardized acupuncture regimen (SAR) and amitriptyline hydrochloride for the relief of pain due to HIV-related peripheral neuropathy in HIV-infected patients. DESIGN: Randomized, placebo-controlled, multicenter clinical trial. Each site enrolled patients into 1 of the following 3 options: (1) a modified double-blind 2 x 2 factorial design of SAR, amitriptyline, or the combination compared with placebo, (2) a modified double-blind design of an SAR vs control points, or (3) a double-blind design of amitriptyline vs placebo. SETTING: Terry Beirn Community Programs for Clinical Research on AIDS (HIV primary care providers) in 10 US cities. PATIENTS: Patients with HIV-associated, symptomatic, lower-extremity peripheral neuropathy. Of 250 patients enrolled, 239 were in the acupuncture comparison (125 in the factorial option and 114 in the SAR option vs control points option), and 136 patients were in the amitriptyline comparison (125 in the factorial option and 11 in amitriptyline option vs placebo option). INTERVENTIONS: Standardized acupuncture regimen vs control points, amitriptyline (75 mg/d) vs placebo, or both for 14 weeks. MAIN OUTCOME MEASURE: Changes in mean pain scores at 6 and 14 weeks, using a pain scale ranging from 0.0 (no pain) to 1.75 (extremely intense), recorded daily. RESULTS: Patients in all 4 groups showed reduction in mean pain scores at 6 and 14 weeks compared with baseline values. For both the acupuncture and amitriptyline comparisons, changes in pain score were not significantly different between the 2 groups. At 6 weeks, the estimated difference in pain reduction for patients in the SAR group compared with those in the control points group (a negative value indicates a greater reduction for the "active" treatment) was 0.01 (95% confidence interval [CI], -0.11 to 0.12; P=.88) and for patients in the amitriptyline group vs those in the placebo group was -0.07 (95% CI, -0.22 to 0.08; P=.38). At 14 weeks, the difference for those in the SAR group compared with those in the control points group was -0.08 (95% CI, -0.21 to 0.06; P=.26) and for amitriptyline compared with placebo was 0.00 (95% CI, -0.18 to 0.19; P=.99). CONCLUSIONS: In this study, neither acupuncture nor amitriptyline was more effective than placebo in relieving pain caused by HIV-related peripheral neuropathy.

Selection in persistently infected murine cells of an MHV-A59 variant with extended host range.

Murine coronavirus MHV-A59 normally infects only murine cells in vitro and causes transmissible infection only in mice. In the 17 C1 1 line of murine cells, the receptor for MHV-A59 is MHVR, a biliary glycoprotein in the carcinoembryonic antigen (CEA) family of glycoproteins. We found that virus released from the 600th passage of 17 C1 1 cells persistently infected with MHV-A59 (MHV/pi600) replicated in hamster (BHK-21) cells. The virus was passaged and plaque-purified in BHK-21 cells, yielding the MHV/BHK strain. Because murine cells persistently infected with MHV-A59 express a markedly reduced level of MHVR (Sawicki, et al., 1995), we tested whether virus with altered receptor interactions was selected in the persistently infected culture. Infection of 17 C1 1 cells by MHV-A59 can be blocked by treating the cells with anti-MHVR MAb-CC1, while infection by MHV/BHK was only partially blocked by MAb-CC1. MHV/BHK virus was also more resistant than wild-type MHV-A59 to neutralization by purified, recombinant, soluble MHVR glycoprotein (sMHVR). Cells in the persistently infected culture may also express reduced levels of and have altered interactions with some of the Bgp-related glycoproteins that can serve as alternative receptors for MHV-A59. Unlike the parental MHV-A59 which only infects murine cells, MHV/BHK virus was able to infect cell lines derived from mice, hamsters, rats, cats, cows, monkeys and humans. However, MHV/BHK was not able to infect all mammalian species, because a pig (ST) cell line and a dog cell line (MDCK I) were not susceptible to infection. MHV/pi600 and MHV/BHK replicated in murine cells more slowly than MHV-A59 and formed smaller plaques. Thus, in the persistently infected murine cells which expressed a markedly reduced level of MHVR, virus variants were selected that have altered interactions with MHVR and an extended host range. In vivo, in mice infected with coronavirus, virus variants with altered receptor recognition and extended host range might be selected in tissues that have low levels of receptors. Depending upon the tissue in which such a virus variant was selected, it might be shed from the infected animal or eaten by a predator, thus presenting a possible means for initiating the transition of a variant virus into a new host as a model for an emerging virus disease.

Mortality differences between black and white men in the USA: contribution of income and other risk factors among men screened for the MRFIT. MRFIT Research Group. Multiple Risk Factor Intervention Trial.

BACKGROUND: Studies of underlying differences in adult mortality between black and white individuals in the USA have been constrained by limitations of data or small study size. We investigated the extent to which differences in socioeconomic position between black and white men contribute to differences in all-cause and cause-specific mortality. METHODS: 361,662 men were screened for the Multiple Risk Factor Intervention Trial between 1973 and 1975, in 22 sites. Median family income of households by zipcode (postal) area of residence was available for 20,224 black and 300,685 white men as well as data on age, cigarette smoking, blood pressure, serum cholesterol, previous heart attack, and treatment for diabetes. We classified deaths during 16 years of follow-up into specific causes and compared differences in death rates between black men and white men, before and after adjustment for differences in income and other risk factors. FINDINGS: Age-adjusted relative risk of death (black vs white) was 1.47 (95% CI 1.42-1.53). Adjustment for diastolic blood pressure, serum cholesterol, cigarette smoking, medication for diabetes, and previous admission to hospital for heart attack decreased the relative risk to 1.40 (1.35-1.46). Adjustment for income but not the other risk factors decreased the risk to 1.19 (1.14-1.24) and adjustment for other risk factors did not alter this estimate. For cardiovascular death, relative risk on adjustment for income was decreased from 1.36 to 1.09; for cancer from 1.47 to 1.25; and for non-cardiovascular and non-cancer deaths from 1.71 to 1.26. For some specific causes of death, including prostate cancer, myeloma, and hypertensive heart disease, the higher death rates among black men did not seem to reflect differences in income. Rates of death for suicide and melanoma were lower among black than white men, as were those for coronary heart disease after adjustment for income. INTERPRETATION: Socioeconomic position is the major contributor to differences in death rates between black and white men. Differentials in mortality from some specific causes do not simply reflect differences in income, however, and more detailed investigations are needed of how differences are influenced by environmental exposures, lifetime socioeconomic conditions, lifestyle, racism, and other sociocultural and biological factors.

The effects of diuresis on the pharmacokinetics of the loop diuretics furosemide and torsemide in patients with heart failure.

PURPOSE: To evaluate the pharmacokinetics of furosemide and torsemide before and after diuresis in patients presenting with marked fluid overload. SUBJECTS AND METHODS: We studied 44 patients with New York Heart Association class III or IV heart failure, ejection fraction < or =40%, and an estimated excess fluid body weight > or =6.8 kg. Oral furosemide or torsemide was administered before and after diuresis. Pharmacokinetic parameters were assessed before and after diuresis. RESULTS: Following diuresis, maximum plasma concentration increased from 11.0+/-5.0 microg/mL to 13.9+/-6.8 with torsemide (P <0.05) and from 3.1< or =1.5 to 3.9+/-1.9 with furosemide (P=0.16). Maximum concentration increased by more than 30% in only one third of the patients. Total absorption (by area under the curve method) increased 6% among patients on torsemide (P=0.38) and 7% among patients on furosemide (P=0.63) and increased >30% in only 1 torsemide and 2 furosemide patients. The time to maximum concentration decreased from 1.40+/-.82 h to 0.81+/-0.36 with torsemide (P <0.01). There were no differences between furosemide and torsemide in the effects of edema on absorption. CONCLUSION: Marked diuresis altered the pharmacokinetics of both furosemide and torsemide in only a small percentage of patients. The use of adequate doses of oral diuretics in edematous patients may be successful, thereby permitting home treatment with oral diuretics and avoiding the cost of hospitalizations or home intravenous administration services.

Evidence for a neurotensin receptor in rat serosal mast cells.

OBJECTIVE AND DESIGN: The ability of neurotensin (NT) at nmolar levels to stimulate exocytosis of the mast cell suggested that it could play a role in neuro-immune-endocrine interactions. The inhibition by a specific receptor antagonist of NT's mast cell stimulation suggested the presence of a specific mast cell NT receptor. We have here employed several probes to determine if a specific neurotensin receptor was present on rat serosal mast cells. MATERIAL: Serosal mast cells were isolated from the peritoneal and pleural cavities of male Sprague-Dawley rats. METHODS: Immunocytochemistry with an antibody raised against the C-terminal peptide of the neurotensin receptor was utilized. The same antibody was employed in immunoblotting following SDS gel electrophoresis of mast cell extracts. An RNA probe for ribonuclease protection assays (RPA) was prepared using the rat brain neurotensin receptor cDNA and polymerase chain reaction was carried out using primers based on the rat brain neurotensin receptor sequence. RESULTS: Mast cells showed specific staining with the anti-neurotensin receptor antibody and this same antibody revealed a protein on SDS gels migrating as a 70 kDa species. Ribonuclease protection assays revealed the predicted protected fragment at approximately 450 bp while PCR amplification gave a major product at 843 bp. CONCLUSIONS: These results indicate that a specific neurotensin receptor is present on the rat mast cell.

Acyclovir use and survival among human immunodeficiency virus-infected patients with CD4 cell counts of < 500/mm3. The Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA).

To examine the relationship between acyclovir use and survival in AIDS, we performed a retrospective analysis of data collected through an observational cohort of the 17-site Community Program for Clinical Research on AIDS (CPCRA), under the sponsorship of the National Institute of Allergy and Infectious Diseases. Data were analyzed regarding 2,368 patients with CD4+ lymphocyte counts of < 500/mm3, and 7,836 follow-up visits were conducted from September 1990 to July 1994. Factors associated with use of acyclovir were studied by stratified analysis of variance and Mantel-Haenzel chi 2 tests. The association between acyclovir and survival was studied with use of the proportional hazards regression model. Individuals reporting acyclovir use were more likely to be white, male, and homosexual; to have a history of herpes simplex and zoster; and to have lower CD4+ T cell counts than those who did not. After adjustments for differences in baseline factors, acyclovir use was not associated with prolonged survival.

The murine coronavirus mouse hepatitis virus strain A59 from persistently infected murine cells exhibits an extended host range.

In murine 17 Cl 1 cells persistently infected with murine coronavirus mouse hepatitis virus strain A59 (MHV-A59), expression of the virus receptor glycoprotein MHVR was markedly reduced (S. G. Sawicki, J. H. Lu, and K. V. Holmes, J. Virol. 69:5535-5543, 1995). Virus isolated from passage 600 of the persistently infected cells made smaller plaques on 17 Cl 1 cells than did MHV-A59. Unlike the parental MHV-A59, this variant virus also infected the BHK-21 (BHK) line of hamster cells. Virus plaque purified on BHK cells (MHV/BHK) grew more slowly in murine cells than did MHV-A59, and the rate of viral RNA synthesis was lower and the development of the viral nucleocapsid (N) protein was slower than those of MHV-A59. MHV/BHK was 100-fold more resistant to neutralization with the purified soluble recombinant MHV receptor glycoprotein (sMHVR) than was MHV-A59. Pretreatment of 17 Cl 1 cells with anti-MHVR monoclonal antibody CC1 protected the cells from infection with MHV-A59 but only partially protected them from infection with MHV/BHK. Thus, although MHV/BHK could still utilize MHVR as a receptor, its interactions with the receptor were significantly different from those of MHV-A59. To determine whether a hemagglutinin esterase (HE) glycoprotein that could bind the virions to 9-O-acetylated neuraminic acid moieties on the cell surface was expressed by MHV/BHK, an in situ esterase assay was used. No expression of HE activity was detected in 17 Cl 1 cells infected with MHV/BHK, suggesting that this virus, like MHV-A59, bound to cell membranes via its S glycoprotein. MHV/BHK was able to infect cell lines from many mammalian species, including murine (17 Cl 1), hamster (BHK), feline (Fcwf), bovine (MDBK), rat (RIE), monkey (Vero), and human (L132 and HeLa) cell lines. MHV/BHK could not infect dog kidney (MDCK I) or swine testis (ST) cell lines. Thus, in persistently infected murine cell lines that express very low levels of virus receptor MHVR and which also have and may express alternative virus receptors of lesser efficiency, there is a strong selective advantage for virus with altered interactions with receptor (D. S. Chen, M. Asanaka, F. S. Chen, J. E. Shively, and M. M. C. Lai, J. Virol. 71:1688-1691, 1997; D. S. Chen, M. Asanaka, K. Yokomori, F.-I. Wang, S. B. Hwang, H.-P. Li, and M. M. C. Lai, Proc. Natl. Acad. Sci. USA 92:12095-12099, 1995; P. Nedellec, G. S. Dveksler, E. Daniels, C. Turbide, B. Chow, A. A. Basile, K. V. Holmes, and N. Beauchemin, J. Virol. 68:4525-4537, 1994). Possibly, in coronavirus-infected animals, replication of the virus in tissues that express low levels of receptor might also select viruses with altered receptor recognition and extended host range.