The myenteric plexus of the rat colon after fecal stream diversion: a morpho-quantitative study

The myenteric plexus undergoes adaptive changes under several conditions. Mucosal and muscular alterations of the colon have been described after fecal stream diversion but studies concerning the myenteric plexus after this procedure are scarce. Therefore, 28 Wistar rats were submitted to fecal diversion and followed for different periods (30, 60, 120 and 180 days), in order to study the myenteric plexus of the excluded segments. Seven non-operated rats were employed as control. The myenteric plexus was subsequently evaluated with the NADH and NADPH histochemical techniques. The colonic area of excluded segments is significantly decreased. The density of NADH-stained neurons continuously increases during the entire postoperative period but does not match the extent of surface reduction. Neuronal area measurements suggest hypertrophy of the remaining neurons in the late postoperative period. Morphological alterations of myenteric ganglia and neurons were also evident. An important surface area reduction combined with slight density increase points toward significant neuronal loss after fecal diversion. While studies correlating neuronal loss and functional changes are still lacking, surgeons should bear in mind the modifications of the myenteric plexus when performing fecal stream diversion surgeries.     

Predicting death from HIV/AIDS: a case-control study from Florida public HIV/AIDS clinics

BACKGROUND: After markedly decreasing for 3 years, HIV/AIDS mortality declined only slightly in 1999. METHODS: The authors conducted a case-control study in four Florida urban public health HIV clinics to evaluate modifiable factors associated with HIV/AIDS mortality in a non-research setting. Structured chart review was conducted for 120 case-patients who died in 1999 and for 240 randomly selected control-patients. Risk factors associated with death in univariate analysis were entered into three conceptually related, matched logistic regression models. RESULTS: In the final multivariate model, homelessness (adjusted odds ratio [AOR], 9.98; 95% confidence interval [CI], 2.34-42.5), Medicaid insurance (AOR, 3.10; 95% CI, 1.43-6.74), having a documented adherence problem (AOR, 3.50; 95% CI, 1.64-7.47), injection drug use (AOR, 2.46; 95% CI, 1.11-5.43), non-specific liver failure (AOR, 76.9; 95% CI, 6.79-870.9), interrupted highly active antiretroviral therapy (HAART) secondary to side effects (AOR, 4.00; 95% CI, 1.46-10.9), and not receiving HAART (AOR, 2.62; 95% CI, 1.03-6.68) were independent predictors of mortality. CONCLUSIONS: In addition to medical and clinical indicators, several sociobehavioral-demographic factors remained important throughout the multivariate analysis. Improvement in care should include a focus on social circumstances of infected people. Special attention to the homeless, those with adherence problems, and those with liver disease is clearly indicated.     

Superficial bladder tumors in patients under 40 years of age: clinical, prognostic and cytogenetic aspects

Bladder carcinoma with transitional cells is the most frequent neoplasia in the urinary system, but it is quite rare in patients under 40 years of age (0.4-2%). An analysis of 21 patients under 40 and a review of other reports show that tumors in patients under 20 years old have little tendency to recur and to progress, while tumors in patients aged between 21 and 40 have a behavior pattern similar to older age groups regarding recurrence and disease progression. Preliminary results of a study using fluorescent in situ hybridization with probes for the centromere of chromosomes 7 and 17 showed a high incidence of aneusomy with regard to these chromosomes and a genetic difference between superficial tumors in the young and in adults. Using probes from chromosomes already described in bladder carcinogenesis, we obtained higher sensitivity and specificity in detecting aneuploid events.     

Influenza virus infection of mouse lymphoblasts alters the binding affinity of anti-H-2 antibody: Requirement for viral neuraminidase

The requirement for histocompatibility in the T lymphocyte killing of virus-infected cells has led us to investigate the effect of influenza virus infection on mouse cell surface histocompatibility (H-2) antigens. Monoclonal anti-H-2 antibody made it possible to develop equilibrium binding conditions for the assay of H-2 antigen-antibody interactions on intact cells. Scatchard analysis of anti-H-2 binding with normal and virus-infected cells yielded linear curves indicating homogeneity of the interaction at varied concentrations of antibody through saturating levels. The estimated number of 2 × 10⁵ - 5 × 10⁵ H-2 antigenic sites per mouse lymphoblast does not appear to change during the course of influenza virus infection. However, the K_a (binding affinity constant) of anti-H-2 binding is rapidly elevated by virus infection (“0” time), continues to increase for 3 h post infection, then decreases. Control cells, treated with normal egg allantoic fluid, show no change in K_a during similar incubation. This change in K_a requires the presence of active viral neuraminidase. Thermal denaturation of the neuraminidase of the virus particles abolishes their ability to induce K_a alteration, even though hemagglutinin activity is retained. Treatment of cells with neuraminidase of bacterial origin led to an elevation of K_a, but did not mimic the viral effect in time dependence and magnitude of peak responses. The time-dependent lowering of K_a from peak values appeared to relate to virus replication, since UV light-inactivated virus-induced K_a elevation, but did not produce the typical K_a decline at 4-5 h post infection. The changes in K_a of anti-H-2 binding during influenza infection reflects a virus- induced alteration of the H-2 molecule or its environment in the host cell membrane. The molecular basis of this change and its relation to H-2-restricted recognition of influenza virus-infected cells by cytotoxic T cells requires further study.     

Effects of combined pre- and post-natal protein deprivation on the myenteric plexus of the esophagus of weanling rats： A histochemical, quantitative and ultrastructural study

AIM： TO evaluate the effects of protein deprivation on the myenteric plexus of the esophagus of weanling rats. METHODS： Pregnant female Wistar rats were divided into 2 groups： nourished （N）, receiving normal diet, and undernourished （D）, receiving a protein-deprived diet, which continued after birth. At twenty-one days of age, 13 esophagi from each group were submitted to light microscopy and morphometrical analysis employing the NADH diaphorase, NADPH diaphorase and acetylcholinesterase techniques. Three other esophagi from each group were evaluated with transmission electron microscopy （TEM）. RESULTS： In both the NADH- and the NADPH-reactive mounts, the neurons of the N mounts were more intensely stained, while in the D esophagi only the larger neurons were reactive. Many myenteric neurons of N were intensely reactive for AChE activity but only a few neurons of D exhibited these aspects. Ultrastructural analysis revealed that the granular reticulum of N showed large numbers of ribosomes aligned on the outer surface of its regularly arranged membrane while the ribosomes of D were disposed in clusters. The chromatin was more homogeneously scattered inside the neuron nucleus of N as well as the granular component of the nucleolus was evidently more developed in this group. Statistically significant differences between N and D groups were detected in the total estimated number of neurons stained by the NADPH technique. CONCLUSION： The morphological and quantitative data shows that feeding with protein-deprived diet in 21-d old rats induces a delay in the development of the myenteric neurons of the esophagus.     

Bipolar disorder in late life: clinical characteristics in a sample of older adults admitted for manic episode

Background

Although manic episodes in older adults are not rare, little published data exist on late-life manic episodes. Resistance to treatment and concomitant neurological lesions are frequent correlates of elderly mania. The aim of this study was to investigate the prevalence of hospitalizations due to mania in patients older than 64 years through a period of 5 years in an Italian public psychiatric ward. Moreover, we aimed at describing clinical presentation of elderly manic episodes.

Methods

A retrospective chart review was conducted in order to describe clinical presentation of 20 elderly patients hospitalized for manic episode; moreover, we compared age at onset, the presence of family history for mood disorders, psychosis and irritability between the elderly group and a matched group of 20 younger manic inpatients.

Results

Seven percent of the whole inpatient elderly people suffered from mania. Half of those patients had a mood disorder age at onset after 50 years and 5 patients were at their first manic episode. Geriatric- and adulthood mania showed similar clinical presentation but younger people had more frequently a mood disorders family history.

Conclusion

Half of our older manic inpatients consisted of "classic" bipolar patients with an extension of clinical manifestations into later life; the other half of our sample was heterogeneous, even though it was not possible to identify clearly which patients may have had vascular lesions related to the onset of mania.

     

Men Who have Sex with Men: Racial/Ethnic Disparities in Estimated HIV/AIDS Prevalence at the State and County Level, Florida

Population-based HIV/AIDS prevalence estimates among men who have sex with men (MSM) have been unavailable, but have implications for effective prevention efforts. Prevalent (living) Florida HIV/AIDS cases reported through 2006 (numerators) were stratified by race/ethnicity and HIV exposure category. Based on previous research, MSM populations were posited as 4–10% of all males aged ≥13 years in each subgroup (denominators). At the estimated lower and upper plausible bounds, respectively, HIV/AIDS prevalence per 100,000 MSM was significantly higher among black (8,292.6–20,731.4); Hispanic (5,599.5–13,998.7); and Asian/Pacific Islander, American Indian or multi-racial (4,942.6–12,356.8) MSM than among white MSM (3,444.9–8,612.3). HIV/AIDS prevalence among all MSM was 13.8–36.9 times that among all other males. Across 19 high-morbidity counties, MSM HIV/AIDS prevalence was highest among those in the most populous counties and highest among blacks. This methodology, adaptable by other states, facilitates calculation of plausible MSM HIV/AIDS prevalence to guide HIV prevention/care community planners and MSM.     

Morphometry and acetylcholinesterase activity of the myenteric neurons of the mouse colon in the chronic phase of experimental Trypanosoma cruzi infection.

The myenteric plexus of the proximal colon, midcolon, and distal colon was studied in mice chronically infected with the Y strain of Trypanosoma cruzi by means of histochemical methods for NADH-diaphorase and acetylcholinesterase (AChE) on whole mount preparations. Ganglia of infected mice displayed an irregular distribution, with neurons severely altered in form and were found side by side with slightly degenerated or morphologically normal ones. Significant reductions of at least 36% in the numbers of neurons were recorded in all regions of the colons of infected animals, especially in the distal colon where the neuron number decreased by more than 44%. Measurements of neuron size suggest that the neuronal destruction caused by T. cruzi affected the medium and large neurons. The small neurons apparently were not affected by the infection. The histochemical demonstration of AChE by the direct coloring copper ferrocyanide method showed that in the control animals, most of the neurons of the plexus displayed AChE activity in the cytoplasm although the neurons showed different reaction intensities. The AChE activity was also present, but at a lower intensity, in the myenteric plexus of the colons of infected animals. These results suggest that the T. cruzi infection affects some categories of neurons and implies that some particular enteric neurotransmitter systems could be affected and the potency of their action upon intestinal function consequently reduced.     

Limitations of blood pressure target in non-dialysis chronic kidney disease: a question of method?

International guidelines recommend to reduce blood pressure (BP) levels below 130/80 mmHg in non-dialysis chronic kidney disease (CKD) patients. However, this BP target has not been validated by randomized controlled trials and is mainly driven by data obtained in observational and post-hoc analyses suggesting that it improves the renal and, to some extent, cardiovascular prognosis. The inconclusive results on the prognostic role of the BP target in patients with CKD might also relate to the limited ability of office BP readings to adequately stratify the global risk of this population. In fact, alterations of the pressure profile (such as white-coat hypertension) and nighttime hypertension are common in CKD patients. Recent studies have demonstrated that ambulatory blood pressure monitoring (ABPM) is superior to clinic BP measurements in predicting renal death and cardiovascular events. Therefore, while waiting for the results from the ongoing randomized Systolic Blood Pressure Intervention Trial (SPRINT) comparing the effect on cardiorenal prognosis of two BP target levels, the more widespread use of ABPM is desirable in CKD patients.