Improving the care of ESRD patients: a success story

Medicare's health care quality improvement program (HCQIP) is a national effort to improve beneficiaries' quality of care. The end stage renal disease (ESRD) HCQIP was implemented in 1994 in response to criticism about the poor quality of care received by ESRD patients. Quality improvement efforts initiated by the ESRD Networks and dialysis providers in response to the HCQIP have demonstrated substantial improvement in care for dialysis patients. This article describes the evolution of the ESRD HCQIP and its successful application in the ESRD program.     

Serological criteria for evaluation and licensure of new pneumococcal conjugate vaccine formulations for use in infants

The World Health Organization (WHO) is undertaking a series of consultations on serological criteria for the evaluation and licensure of new formulations/combinations or different vaccination schedules of pneumococcal conjugate vaccines. The lack of a definitive serological correlate of protection and the multiplicity of antigens involved, especially since the clinical efficacy of most of the individual serotypes represented in the only licensed vaccine has not been established, are hindering the formulation of criteria for licensure of new formulations or combinations of the vaccine. This report analyses the various options with their relative merits and drawbacks and provides preliminary recommendations as guidance to regulatory agencies in evaluating these vaccines for the purposes of licensure. More detailed recommendations for production and control of pneumococcal conjugate vaccines, including criteria for evaluation for licensure, are currently being drafted.     

Susceptibility of black fly larvae (Diptera: Simuliidae) to lawn-care insecticides individually and as mixtures

Urban and suburban watersheds have the potential to be highly impacted by chemicals, especially insecticides to control insect pests on lawns, ornamental plants, and home gardens. Three of the most common lawn-care insecticides detected in urban watersheds, carbaryl, chlorpyrifos, and malathion, have been evaluated using an acute orbital shaker toxicity test to determine their respective concentrations that produce 50% mortality (LC50) in Simulium vittatum Zetterstedt cytospecies IS-7 larvae. Results of the 48-h LC50 tests show chlorpyrifos to be the most toxic to black fly larvae (LC50 = 0.28 microg/L) followed by carbaryl (LC50 = 23.72 microg/L) and malathion (LC50 = 54.20 microg/L). These insecticides were also tested as binary and ternary mixtures using the toxic unit (TU) approach. Toxicity was shown to be greater than additive for the ternary mixture of chlorpyrifos-carbaryl-malathion (LC50 = 0.56 TU) and the binary mixtures of chlorpyrifos-malathion (LC50 = 0.72 TU) and carbaryl-malathion (LC50 = 0.78 TU). The binary combination of chlorpyrifos and carbaryl was shown to be additive (LC50 = 0.98 TU). These results indicate that aquatic invertebrate populations in urban and suburban streams may experience a higher-than-expected increase in toxicity-related effects when all three chemicals are present in the waterway.     

Predicting sediment toxicity using logistic regression: a concentration-addition approach

The question posed in this article is how useful the chemical concentration measurements for predicting the outcome of sediment toxicity tests are. Using matched data on sediment toxicity and sediment chemical concentrations from a number of studies, we investigated several approaches for predicting toxicity based on multiple logistic regression with concentration-addition models. Three models were found to meet criteria for acceptability. The first model uses individual chemicals selected using stepwise selection. The second uses derived variables to reflect combined metal contamination, polycyclic aromatic hydrocarbon (PAH) contamination, and the interaction between metals and PAHs. The third and final model is a separate species model with derived variables. Overall, these models suggest that toxicity may be correctly predicted approximately 77% of the time, although prediction is better for samples identified as nontoxic than for those known to be toxic.     

Profile of urinary arsenic metabolites during pregnancy

Chronic exposure to inorganic arsenic (In-As) from drinking water is associated with different health effects, including skin, lung, bladder, and kidney cancer as well as vascular and possibly reproductive effects. In-As is metabolized through the process of methylation, resulting in the production and excretion of methylated species, mainly monomethylarsenate (MMA) and dimethylarsenate (DMA). Because a large percentage of the dose is excreted in urine, the distribution of urinary In-As, MMA, and DMA is considered a useful indicator of methylation patterns in human populations. Several factors affect these patterns, including sex and exposure level. In this study, we investigated the profile of urinary In-As, MMA, and DMA of pregnant women. Periodic urine samples were collected from early to late pregnancy among 29 pregnant women living in Antofagasta, Chile, who drank tap water containing 40 micro g/L In-As. The total urinary arsenic across four sampling periods increased with increasing weeks of gestation, from an initial mean value of 36.1 to a final value of 54.3 micro g/L. This increase was mainly due to an increase in DMA, resulting in lower percentages of In-As and MMA and a higher percentage of DMA. Our findings indicate that among women exposed to moderate arsenic from drinking water during pregnancy, changes occur in the pattern of urinary arsenic excretion and metabolite distribution. The toxicologic significance of this is not clear, given recent evidence suggesting that intermediate methylated species may be highly toxic. Nevertheless, this study suggests that arsenic metabolism changes throughout the course of pregnancy, which in turn may have toxicologic effects on the developing fetus. Key words: arsenic, arsenic metabolism, arsenic methylation, Chile, pregnancy, urinary arsenic.     

Association of co-occurring psychosocial health problems and increased vulnerability to HIV/AIDS among urban men who have sex with men

OBJECTIVES: We measured the extent to which a set of psychosocial health problems have an additive effect on increasing HIV risk among men who have sex with men (MSM). METHODS: We conducted a cross-sectional household probability telephone sample of MSM in Chicago, Los Angeles, New York, and San Francisco. RESULTS: Psychosocial health problems are highly intercorrelated among urban MSM. Greater numbers of health problems are significantly and positively associated with high-risk sexual behavior and HIV infection. CONCLUSIONS: AIDS prevention among MSM has overwhelmingly focused on sexual risk alone. Other health problems among MSM not only are important in their own right, but also may interact to increase HIV risk. HIV prevention might become more effective by addressing the broader health concerns of MSM while also focusing on sexual risks.     

Open-lung protective ventilation with pressure control ventilation, high-frequency oscillation, and intratracheal pulmonary ventilation results in similar gas exchange, hemodynamics, and lung mechanics

BACKGROUND: Pressure control ventilation (PCV), high-frequency oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. METHODS: Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of Pao2/Fio2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H2O. Animals were then ventilated for 4 h. RESULTS: There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 +/- 2.1 ml/kg; ITPV, 2.7 +/- 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 +/- 2.6 cm H2O; ITPV, 22.3 +/- 4.8 cm H2O; HFO, approximately 24.3 cm H2O) were higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. CONCLUSION: These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.     

Long-term function after Charnley total hip arthroplasty

The purpose of this study was to report the functional results and mortality rates of a consecutive series of patients younger than 50 years after Charnley total hip arthroplasty. The original group of 69 patients (93 hips) was followed up until death or a minimum of 25 years after surgery. Of the original 93 hips, 29 had been revised at some point. Functional outcomes included the Short Form-36, Western Ontario and McMaster University University Osteoarthritis Index (WOMAC), 6-minute walk distance, Noyes activity scale, and Harris hip scores and included followup in 42 of 43 living patients. The functional outcome of patients was good, with comparable Short Form-36 scores compared with normative values of healthy age-matched subjects. The 6-minute walk distances and WOMAC scores were slightly lower than healthy normatives but were thought to be influenced by medical comorbidities. Although comorbid medical and musculoskeletal conditions significantly hindered most measures of function, revision surgery or radiographic loosening of components had no significant influence on function. The mortality rates of this cohort of patients were similar to normative values at both 10 and 25 years after surgery.     

A randomized,placebo controlled,multicenter study to evaluate the safety and efficacy of rofecoxib in the treatment of chronic nonbacterial prostatitis

PURPOSE: We determine the effects of treatment with rofecoxib and placebo in patients with chronic prostatitis. MATERIALS AND METHODS: Patients diagnosed with chronic nonbacterial prostatitis were randomized to 6 weeks of 25 or 50 mg., rofecoxib or placebo in a double-blind multicenter study with a 1-week run in of placebo. End points included the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) (average pain score item 4 primary end point), and patient global assessment questions of pain, disease activity and response to therapy. RESULTS: A total of 161 patients were randomized in the study. The NIH-CPSI total, domain and pain scores significantly decreased from baseline in all groups and, although the mean scores numerically favored the rofecoxib groups, the difference was not significantly different among groups. There was a trend for the percentage of patients with a 25% (or 6 point) improvement in total score being superior on rofecoxib versus placebo with the difference being significantly different (p <0.05) for the 50 mg. rofecoxib group. Patient global assessment of pain, response to therapy and disease activity also favored rofecoxib over placebo (p <0.05, p = 0.07, p = 0.06, respectively). Of the patients 79% on 50 mg. rofecoxib versus 59% on placebo reported no or mild pain, and 56% of patients on 50 mg. rofecoxib versus 27% on placebo experienced significant improvement in quality of life (p <0.005). Rofecoxib was generally well tolerated. CONCLUSIONS: To our knowledge this study is the first to evaluate rofecoxib versus placebo in patients with prostatitis and the first large multicenter treatment study to use the NIH-CPSI. Subjective assessment with patient global questions may be more sensitive to change than the NIH-CPSI and, therefore, may be a better tool to use in future therapeutic trials. Although 6 weeks of rofecoxib treatment appear to benefit many men diagnosed with chronic prostatitis/chronic pelvic pain syndrome further studies are needed.