Community-acquired Clostridium difficile: epidemiology, ribotype, risk factors, hospital and intensive care unit outcomes, and current and emerging therapies.

BACKGROUND: The epidemiological landscape of Clostridium difficile infection (CDI) has changed over the past 30 years. AIM: To review studies of CDI in the community setting. METHODS: Electronic databases including PubMed, MEDLINE, Embase, Google Scholar, Scopus, ClinicalTrials.gov and Cochrane Databases were searched for human studies performed between 2000 and 2017 that assessed the epidemiology, risk factors, ribotypes, hospital and intensive care unit (ICU) outcomes, and management of community-acquired CDI. In addition, references were searched manually to identify other relevant studies. FINDINGS: In total, 39 articles met the inclusion criteria. The incidence of community-acquired CDI has almost doubled in the past decade. Approximately half of all cases of CDI are attributed to community origin. Individuals who are younger, female, in the presence of infants, frequently use proton pump inhibitors or specific classes of antibiotics, or live near farms and livestock are at higher risk for community-acquired CDI. Additionally, approximately 40% of all community-acquired cases require hospitalization, where severity has been linked to hypervirulent ribotypes 027 and 078 with poor outcomes. Emerging data on treatment paradigms have led to the revision of clinical guidelines and two potential vaccines in phase three clinical trials. However, ribotype-specific responses to current treatment strategies are lacking. CONCLUSION: Community-acquired CDI represents a growing public health threat and burden on healthcare systems. A multi-disciplinary approach will be required to stem the tides.

Methotrexate-induced posterior reversible encephalopathy syndrome.

WHAT IS KNOWN AND OBJECTIVE: Posterior reversible encephalopathy syndrome (PRES) is described clinically as an acute neurologic deterioration characterized by headache, change in mental status and seizures. Although the mechanism(s) for this syndrome is not fully understood, PRES results from vasogenic edema in areas of the brain supplied by the posterior circulation. Methotrexate (MTX)-induced neurotoxicity is a well-known complication of therapy in the paediatric population but is uncommon in adults. DETAILS OF THE CASE: We describe a 55-year-old woman with an acute presentation of PRES caused by intrathecal MTX given as part of a treatment regimen for diffuse large B-cell type lymphoma. Both clinical symptoms and radiographic abnormalities resolved 5 days after cessation of treatment. WHAT IS NEW AND CONCLUSION: We describe what we believe to be the first report of intrathecal MTX-induced PRES in an adult. Clinicians should include MTX-induced PRES in the differential diagnosis of acute neurologic changes in patients receiving this medication. The incidence of MTX-induced neurotoxicity may be under recognized in adults.

Use of Tris-hydroxymethyl aminomethane in severe lactic acidosis due to highly active antiretroviral therapy: a case report.

BACKGROUND: Lactic acidosis is a rare, yet life-threatening adverse drug effect of highly active antiretroviral therapy (HAART), specifically stavudine and lamivudine. These nucleoside analogue reverse transcriptase inhibitors (NRTIs) are commonly used to treat patients infected with the human immunodeficiency virus (HIV). CASE: We report the use of Tris-hydroxymethyl aminomethane (THAM) to treat severe lactic acidosis due to HAART in a 50-year-old African-American woman. NRTIs can cause hyperlactinaemia by interfering with mitochondrial oxidative phosphorylation function, which normally removes H(+) generated by the hydrolysis of adenosine triphosphate. This side-effect is associated with a high mortality in patients infected with HIV. One explanation for this high mortality is that lactic acidosis is typically refractory to treatment with commonly used buffering agents. CONCLUSION: THAM generates serum bicarbonate, and reduces the level of carbon dioxide in arterial blood. Both of these qualities appear to make THAM an ideal agent for treating lactic acidosis caused by HAART.

Ethnic differences in body composition and their relation to health and disease in women.

Differences in body composition between black and white women have been well established. Black women have more bone and muscle mass, but less fat, as a percentage of body weight, than white women, after controlling for ethnic differences in age, body weight, and height. In addition, black women have more upper-body fat than white women. These ethnic differences in body composition appear to be associated with disease risk in women. The greater skeletal and muscle mass in black compared to white women appears to protect them from osteoporosis. The relationship between fat distribution and cardiovascular disease also appears to be influenced by ethnicity. This review has two purposes: (1) To examine previous research investigating ethnic differences in body composition between black and white women; and (2) To demonstrate the relationship between body composition and disease in women as a function of ethnicity.

Androgenic regulation of bone mass in women. A review.

In men and women, androgens and estrogens circulate at levels consistent with biologic activity. However, the effects of these steroid hormones on bone metabolism were thought to depend on the gender of the individual; that is, estrogens were thought to regulate bone mass in women, whereas androgens were thought to regulate bone mass in men. It now appears that both of these sex steroids influence bone and mineral metabolism in women. Although a number of clinical studies have indicated that androgen levels are correlated with bone mass measurements in women, it was speculated that androgenic hormones acted on bone tissue indirectly. It now has become apparent that androgens act on bone tissue through a direct receptor-mediated mechanism that may involve growth factor synthesis. The purpose of this review is to examine clinical and basic research aimed at elucidating the mechanism of androgen action on bone tissue in women.

Age-related changes in musculoskeletal mass between black and white women.

Earlier studies from our laboratory indicated that matched black and white women differ significantly in total body potassium (TBK), total body bone density (TBD), and total body bone mineral (TBBM). The aim of this investigation was to examine absolute levels and the kinetics of age-related changes in TBK, TBD, TBBM, and percent body fat in a cross-sectional cohort of 34 matched pairs (age +/- 4 years, weight +/- 2 kg, and height +/- 4 cm) of black and white healthy non-obese women. Black and white women had a similar percentage of body weight as fat, although adipose tissue distribution (ie, waist to hip circumference ratio [WHR]) differed significantly (P < .0007) between the two groups (WHR, mean +/- SD: black, 0.837 +/- 0.062; white, 0.788 +/- 0.043). TBBM and TBD were significantly (P < .0001) higher in young black women, and ethnic differences in total bone mineral mass persisted at all ages. TBK (P = 0.0482) and appendicular skeletal muscle mass (P < .0001) were higher in young black women; however, by ages 60 to 70 years, the two groups had similar TBK. Both groups of women lost musculoskeletal mass (ie, TBK and TBBM) and gained fat mass at similar rates. The results of this study suggest that black women have a greater appendicular muscle and skeletal mass, as well as upper-body fat distribution, than white women. These differences are independent of body weight, height, or percent fat, and the ethnic skeletal differences persist throughout the adult life span. The higher appendicular muscle mass, skeletal mass, and upper-body fat distribution suggest that black women may have greater androgenic activity than white women.