Inherited renal tubular dysgenesis: the first patients surviving the neonatal period

Renal tubular dysgenesis (RTD) is a clinical disorder either acquired during fetal development or inherited as an autosomal recessive condition. Inherited RTD is caused by mutations in the genes encoding the components of the renin-angiotensin system angiotensinogen, renin, angiotensin-converting enzyme and angiotensin II receptor type 1. Inherited RTD is characterized by early onset oligohydramnios, skull ossification defects, preterm birth and neonatal pulmonary and renal failure. The histological hallmark is the absence or poor development of proximal tubules. So far, all patients died either in utero or shortly after birth. We report the first patients with inherited RTD surviving the neonatal period and still being alive. Genetic and functional analysis of the renin-angiotensin system contributes to the diagnosis of RTD. In conclusion, the clinical diagnosis of inherited RTD is easily missed after birth without renal biopsy or information on affected family members. Genetic and functional analysis of the renin-angiotensin system contributes to correct diagnosis.     

Disentangling the effects of racial and weight discrimination on body mass index and obesity among Asian Americans

Objectives. We examined whether racial discrimination is associated with increased body mass index (BMI) and obesity among Asian Americans. Further, we explored whether this association strengthens with increasing time in the United States.Methods. We analyzed data from the 2002 to 2003 National Latino and Asian American Study (n=1956). Regression models tested whether reports of racial discrimination were associated with BMI and obesity, after accounting for weight discrimination, age, gender, marital status, ethnicity, generation, employment, health status, and social desirability bias (the tendency to seek approval by providing the most socially desirable response to a question).Results. We found that (1) racial discrimination was associated with increased BMI and obesity after we controlled for weight discrimination, social desirability bias, and other factors and (2) the association between racial discrimination and BMI strengthened with increasing time in the United States.Conclusions. Racial discrimination may be an important factor related to weight gain among ethnic minorities.Stress caused by disadvantaged social status may be related to obesity. Two elements provide the foundation for this observation. First, stress may have adverse physiological consequences, including increased risk for obesity and allostatic load, the “wear and tear” on organ systems that contributes to health problems.1 Stressors activate the hypothalamic–pituitary–adrenal axis system, releasing cortisol and other glucocorticoids. Glucocorticoids may stimulate appetite and blunt the satiety system.2 Cortisol increases fat retention, particularly in the abdominal region.3 Moreover, stressors may selectively increase the intake of “comfort foods” over other foods among humans and other animals.4^,5Stress may also be related to abdominal and general obesity. Daily stress,6 anxiety,7 and depressed mood8^,9 are related to visceral obesity. Among monozygotic twins, stress-induced hormonal changes result in greater intra-abdominal fat deposits in the twin with higher stress.10 Further, obesity, indicated by a high body mass index (BMI), has been associated with work stress11^,12 and early childhood trauma.13 In a prospective study of British civil servants, job stress was associated with metabolic syndrome (a group of risk factors that includes abdominal obesity, elevated blood pressure, and atherogenic dyslipidemia)8 and general and visceral obesity.12Second, social disadvantage, such as experiences with racial discrimination, may produce stress.14 Self-reported discrimination appears to be related to several stress-related and obesity-related outcomes, including high blood pressure,15 depression and anxiety,16 sleep problems,17 and coronary calcification.18 Individuals may also use alcohol to cope with discrimination,19^–21 and alcohol can contribute to obesity.22 Hence, discrimination may directly produce weight gain by activating the stress system and by influencing behavior change. Discrimination also may act indirectly by hindering socioeconomic advancement23^,24 and by segregating individuals into communities with fewer healthy food options25^,26 and fewer safe places for physical activity.27^,28Consistent with these observations, several studies have suggested that discrimination is associated with weight gain and metabolic problems. Tull et al. found that reports of internalized racism were associated with greater obesity among women in Barbados.29 Similarly, Chambers et al. found associations between internalized racism and insulin resistance among girls in Barbados.30 Butler et al. found associations between internalized racism and greater waist circumference and higher fasting glucose among Dominica women.31We tested the first hypothesis that reports of discrimination are associated with higher BMI and the risk of obesity and build on previous research in 3 primary ways. First, overweight people may encounter weight discrimination,32 and associations between racial discrimination and weight might therefore be confounded by weight discrimination. To reduce the chance of spurious findings, we controlled for weight discrimination and other factors.Second, we examined whether findings from Black populations generalize to Asian Americans. Among Asian Americans, discrimination is associated with outcomes related to obesity, including cardiovascular conditions,33^,34 depression,35^–37 and substance use,19 but no study has directly examined whether discrimination is associated with BMI and obesity in this population.Third, we tested the main effects of discrimination and investigated whether discrimination is moderated by time spent in the United States. US-born Asians appear to have higher rates of obesity than their foreign-born counterparts, but the rates of obesity among the foreign born increase with years in the United States.38^–40 Additionally, immigrants often report less racial discrimination than do nonimmigrants, but reports of discrimination increase with years spent in the United States, perhaps because immigrants are more likely to encounter and recognize discrimination over time.41^–43 A recent study found that among African and Latino immigrants, the association between racial discrimination and mental health strengthened with increasing time in the United States.44 These observations motivate the second hypothesis that time spent in the United States will interact with the association between racial discrimination, such that the association between racial discrimination and BMI among immigrant Asians will strengthen with increasing time spent in the United States.     

The effect of oral acetazolamide on weight gain in children

Objective: Oral acetazolamide is a potent medical treatment for pediatric glaucoma, but ophthalmologists may have concerns that it retards weight gain in children and may choose surgical management instead.Design: Retrospective chart review.Participants: Twenty-two well children with glaucoma taking acetazolamide orally for ≥ 3 months.Methods: Abnormal weight gain was determined using downward crossing of 2 percentile lines on growth charts and change in z score for weight using a hierarchical linear model.Results: One patient with Sturge-Weber syndrome and growth failure was excluded when growth hormone deficiency was diagnosed. Two patients crossed 2 lines downward; both showed metabolic acidosis. The trend for the 2 reversed after medication was discontinued. The other 20 tracked steadily on growth curves. Eleven patients (11/22, 50%) showed a decline in z score for weight over the follow-up period, and the remainder showed an increase, for an overall estimate of slope in this sample of 0.01, which was not significant (p = 0.8).Conclusions: Oral acetazolamide may cause poor weight gain in a small subset of children on treatment. Metabolic acidosis may be a mediating factor for growth failure. Our data suggest that acetazolamide does not cause significant weight changes in cases of pediatric glaucoma. Growth parameters should be followed. Growth hormone deficiency should be considered in Sturge-Weber syndrome. Prospective study is needed.     

Radionuclide arthrogram with SPECT/CT for the evaluation of mechanical loosening of hip and knee prostheses

Objective  

To evaluate the value of SPECT/CT in radionuclide arthrogram (RNA) for the assessment of mechanical loosening of hip and knee prostheses.     

Neuroendocrine tumor of vulva: a case report and review of literature

Neuroendocrine tumor (Merkel cell carcinoma-MCC) of the vulva is a very rare entity with less than 15 cases reported in the English literature. It is known for its aggressive behaviour and propensity for early dissemination. The actual cell of origin and etiology of this disease is controversial. In absence of any definite guidelines for management (due to its rarity), extrapolation of data from extra-vulvar MCC seems logical. We present a case of vulvar neuroendocrine tumor who presented at a locally advanced stage.     

Genetic and Epigenetic Inactivation of Kruppel-like Factor 4 in Medulloblastoma

Although medulloblastoma is the most common pediatric malignant brain tumor, its molecular underpinnings are largely unknown. We have identified rare, recurrent homozygous deletions of Kruppel-like Factor 4 (KLF4) in medulloblastoma using high-resolution single nucleotide polymorphism arrays, digital karyotyping, and genomic real-time polymerase chain reaction (PCR). Furthermore, we show that there is loss of physiological KLF4 expression in more than 40% of primary medulloblastomas both at the RNA and protein levels. Medulloblastoma cell lines drastically increase the expression of KLF4 in response to the demethylating agent 5-azacytidine and demonstrate dense methylation of the promoter CpG island by bisulfite sequencing. Methylation-specific PCR targeting the KLF4 promoter demonstrates CpG methylation in approximately 16% of primary medulloblastomas. Reexpression of KLF4 in the D283 medulloblastoma cell line results in significant growth suppression both in vitro and in vivo. We conclude that KLF4 is inactivated by either genetic or epigenetic mechanisms in a large subset of medulloblastomas and that it likely functions as a tumor suppressor gene in the pathogenesis of medulloblastoma.