Peritonitis in Latin America.

Peritoneal dialysis has a high acceptance rate in Latin America, thus the knowledge concerning complication patterns is of great relevance. This work reviews Latin American data on peritonitis, the most serious complication of peritoneal dialysis. The incidence of peritonitis has been reduced over time, concomitantly with the incorporation of safer exchange systems and the use of prophylactic measurements. Today, rates lower than 1 episode per 24 patient-months are commonly reported. Furthermore, changes in causative organisms have been observed, with predominance of Staphylococcus aureus up through the mid-1990s, as well as increases in coagulase-negative staphylococcus and participation of gram negatives. However, the prevalence of S. aureus is still high, due possibly to climatic conditions and the elevated prevalence of carriers. Resolution rate varies from 55% to 78%, transfer to hemodialysis from 10.9% to 15.4%, and death in 3% to 9.9% of cases. Outcome is worse in S. aureus episodes compared to those with coagulase-negative staphylococcus, despite the higher percentage of oxacillin-resistant strains among the former. In general, despite socioeconomic or climatic conditions, our results are similar to those in developed countries, perhaps as a consequence of technological improvements and/or center expertise.     

Enhancement of heart rate variability by cholinergic stimulation with pyridostigmine in healthy subjects

The purpose of this study was to determine the effect of the oral administration of pyridostigmine bromide on indices of heart rate variability (HRV) in healthy young volunteers. Seventeen healthy participants (11 men, 6 women; aged 27 +/- 8 y) submitted to a randomized, crossover, double-blind protocol, in which they received 30 mg pyridostigmine bromide (PYR) or placebo orally at 8-hour intervals for 24 hours, on two separate days. Venous blood samples were collected 2 and 24 hours after the first dose for determination of serum cholinesterase activity. Holter tapes were recorded during the 24-hour period and analyzed using a semiautomatic technique to evaluate time- and frequency-domain indices of HRV and to build three-dimensional return maps for later quantification. Symptoms were mild and occurred similarly during administration of PYR and placebo (p = 0.140). Serum cholinesterase activity was reduced by 15% at 2 hours (p = 0.013) and by 14% at 24 hours (p = 0.010) after the first dose of PYR, but not after administration of placebo. Pyridostigmine administration caused a significant increase in the mean 24-hour R-R interval (placebo: 814 +/- 20 msec; PYR: 844 +/- 18 msec; p = 0.003) and in time-domain indices of HRV, such as the standard deviation of all R-R intervals (SDNN; placebo: 151 +/- 9 msec; PYR: 164 +/- 9 msec; p = 0.017), and the percentage of pairs of adjacent R-R intervals differing by more than 50 msec (pNN50; placebo: 12.8 +/- 1.8%; PYR: 13.9 +/- 1.5%; p = 0.029). Pyridostigmine had no significant effect on frequency-domain indices of HRV, but resulted in significant increase in P2, a parasympathetic index derived from the three-dimensional return map (placebo: 93 +/- 13 msec; PYR: 98 +/- 13 ms; p = 0.029). In conclusion, low-dose pyridostigmine reduced mean heart rate and increased HRV during a 24-hour period in healthy young subjects.     

A window of opportunity: declining rates of hepatitis B virus infection among injection drug users in Rio de Janeiro, and prospects for targeted hepatitis B vaccination.

OBJECTIVES: To measure hepatitis B virus (HBV) infection rates among injection drug users in Rio de Janeiro, Brazil, and to report their knowledge of and attitudes toward hepatitis and HBV vaccination. METHODS: 609 injection drug users recruited in Rio de Janeiro between 1999 and 2001 answered a questionnaire and were tested for hepatitis B and other blood-borne infections. Questions covered sociodemographic information, alcohol and illicit drug consumption, drug injection and sexual practices, medical history, and knowledge about HIV, AIDS and viral hepatitis. RESULTS: The prevalence of HBV infection was 27.1%, with 3.4% of the sample positive for HbsAg (active infection) and 0.8% positive for anti-HBs (indicating previous HBV vaccination). Most interviewees (81.3%) were aware of at least one form of viral hepatitis and received information from many different sources. In agreement with laboratory findings, 96.7% of the interviewees stated they had never been vaccinated against hepatitis B, but almost all unvaccinated interviewees (97.8%) said they would volunteer to be vaccinated if HBV vaccination were available. CONCLUSIONS: Few of the injection drug users surveyed had ever been vaccinated against HBV. Although most were aware of the risks posed by viral hepatitis, this awareness seldom translated into consistent behavioral change. The participants' willingness to be vaccinated against HBV suggests that the implementation of vaccination for this population may help decrease rates of hepatitis B infection.     

Effect of the pre-brushing rinse, Plax, on dental plaque formation

The aim of this double-blind cross-over study was to investigate plaque accumulation after the use of the pre-brushing rinse Plax, compared to placebo. 10 volunteers underwent 2 treatment periods of 1 week, separated by a wash-out period of 1 week. At the start of each study period, professional tooth-cleaning was performed. On days 2, 4, and 7 of each treatment period, periodic identical photographs after plaque disclosure were taken for planimetric analyses of plaque extension on canines, premolars. During each treatment period, the subjects were supervised when rinsing twice daily for 30 seconds with 15 ml of placebo or Plax, followed by brushing. The subjects performed a standardized poor brushing technique without toothpaste. No significant differences were noted between placebo and Plax for plaque extension on days, 2, 4 and 7. The results show that buccal plaque growth is equal after 2x daily rinsing with Plax and placebo in subjects performing a poor oral hygiene.     

Complement activation in vitro by the red cell substitute, liposome- encapsulated hemoglobin: mechanism of activation and inhibition by soluble complement receptor type 1

BACKGROUND: Liposome-encapsulated hemoglobin (LEH) has been developed as an emergency blood substitute, yet its effect on human complement has never been explored. Considering that complement activation is a major pathogenic factor in the respiratory distress syndrome that often develops in trauma and shock, LEH-induced complement activation may be a critical safety issue. STUDY DESIGN AND METHODS: Various LEH and corresponding empty liposomes were incubated with normal human sera, and various markers of complement activation (serum levels of C4d, Bb, SC5b-9, and CH50; C5a-induced granulocyte aggregation; membrane deposition of C3b) were measured. Incubations were also performed in the presence of (ethylene-bis[oxyethylenenitrilo]tetraacetic acid) (EGTA) and Mg++ (EGTA/Mg++) and soluble complement receptor type 1. RESULTS: LEH and liposomes activated human complement, as indicated by significant changes in one or more markers. The effect was primarily due to the presence of the phospholipid vehicle; small, unilamellar, highly homodispersed vesicles induced the greatest degree of complement activation. Complement activation was partially inhibited by EGTA/Mg++. The latter finding, together with the parallel increases in serum C4d and Bb, suggests activation of both the classical and alternative pathways. Soluble complement receptor type 1 (0.05-20 micrograms/mL) efficiently inhibited all vesicle-induced complement activation. CONCLUSION: Because of complement activation, the use of LEH for transfusion may require careful evaluation of safety. Soluble complement receptor type 1 may be useful as a prophylactic agent for complement activation-related complications of liposome infusions.     

PHB6 Health Care Use in Women Age 45 and Older

Key components of preventive health care for middleaged and older women include evaluating the risk for osteoporosis and coronary artery disease, considering hormone replacement therapy (HRT), and cancer screening. HRT is effective for treating the symptoms of acute menopause, and it may prevent some chronic health problems associated with growing older. However, HRT may increase the risks for other diseases.
OBJECTIVE: The purpose of this study was to estimate the level of health care use and costs incurred by post-menopausal women for conditions that have been associated with HRT.
METHODS: National health care survey and discharge data were used to estimate health care use by women age 45 and older for cardiovascular disease, osteoporosis, breast cancer, uterine cancer, and deep-vein thrombosis/ pulmonary embolism. The databases used were the Healthcare Utilization Project-3, National Ambulatory Medical Care Survey, National Hospital Ambulatory Medical Care Survey, National Nursing Home Survey, and National Home and Hospice Care Survey. Clinical Classification for Health Policy Research codes were used to identify patients whose primary diagnosis or procedure corresponded with the above conditions. National weights were used to estimate resource use. Treatment costs were estimated using cost-to-charge ratios or Medicare Fee Schedule to calculate costs of individual procedures.
RESULTS: For each of the five conditions, resource use and costs are reported for hospitalization, outpatient, nursing home, and home health care services. Resource use and costs are also reported by age and race/ethnicity.
CONCLUSION: Results of the study may be used to estimate the burden of disease for conditions commonly affecting postmenopausal women and to provide data for cost-effectiveness models comparing newly developed drugs to existing HRTs.     

Highly active antiretroviral therapy in Brazil: the challenge of universal access in a context of social inequality.

OBJECTIVE: To investigate trends in AIDS mortality and incidence in Brazil over the period of 1984 to 2000 and to assess the impact of the introduction of universal access to highly active antiretroviral therapy (HAART) in the country in 1996. METHODS: Data from the Brazilian disease notification system and the national mortality information system were used to calculate annual region-specific and sex-specific AIDS incidence and mortality rates. We also calculated sex- and region-specific ratios of the number of AIDS deaths in one year to the number of AIDS cases notified two years earlier. RESULTS: AIDS mortality rates for both men and women and in all five of the geographic regions of Brazil declined following introduction of HAART, despite continued growth in AIDS incidence. The ratio of the number of AIDS deaths in one year to the number of AIDS cases notified two years earlier for men equalized rapidly with the ratio for women following introduction of HAART. More recently, AIDS incidence declined for both sexes and in most of the regions of Brazil. CONCLUSIONS: Despite Brazil's resource limitations and disparities in wealth between men and women and among the country's regions, the introduction of universal access to HAART in Brazil has helped achieve impressive declines in AIDS mortality, and it may also be contributing to declines in AIDS incidence.     

Post-treatment Stability in Orthodontic Retention with Twistflex Retainers—Do Patients Benefit from Additional Removable Retainers?

Clinical Oral Investigations - To evaluate post-treatment movements of lower anterior teeth during orthodontic retention in patients with fixed twistflex retainers versus those with combined fixed...