No evidence for involvement of the calpain-10 gene 'high-risk' haplotype combination for non-insulin-dependent diabetes mellitus in early onset obesity

In light of evidence of linkage of obesity to chromosome 2q31-q37, we hypothesized that the calpain-10 gene 'high-risk' haplotype combination for non-insulin-dependent diabetes mellitus (NIDDM) is involved in early onset obesity. We screened the NIDDM 'high-risk'-haplotype combination formed by the alleles 112 and 121 of the polymorphisms UCSNP-43, -19, and -63 in 166 families consisting of an extremely obese child or adolescent (mean BMI percentile: 99.3+/-1.38), one or more obese sibs (mean BMI percentile: 97.42+/-2.88), and both of their parents. Genotyping for three calpain-10 gene polymorphisms was performed by polymerase chain reaction (PCR) with (a) length polymorphism detection (UCSNP-19) or (b) allele-specific PCR (UCSNP-43 and -63). To allow for correct haplotype assignment all individuals were additionally genotyped for two microsatellite markers (D2S125 and D2S2338). We followed a hierarchical test procedure. As the first step, model-free linkage analysis was performed using maximum likelihood binomial statistics. The second stage consisted of a one-sided asymptotic pedigree disequilibrium test for the UCSNP-43 and on an exploratory level for the other SNP-markers and all haplotypes formed by the three SNPs. The final stage investigated the reported haplotype combination. We failed to detect an initial linkage of obesity to this region (LOD score <0.4). All subsequent exploratory analyses were negative. Our analysis of the relationship between the NIDDM 'high-risk' haplotype combination and extreme early onset obesity revealed no evidence for linkage and association.     

Comparison of antireflux surgery among ethnicity

African Americans appear less likely than caucasians to undergo surgery for gastroesophageal reflux disease (GERD). When they do, they appear to have higher conversion and complication rates. Nevertheless, satisfaction with surgery is similar to caucasians. BACKGROUND: There is little information comparing the prevalence and treatment of GERD in various ethnic populations. The purpose of this study was to examine the variations in outcomes between caucasians and African Americans undergoing antireflux surgery. METHODS: The records of all patients who underwent antireflux surgery for GERD or paraesophageal hernia by a single surgeon from January 1997 through December 2001 were reviewed for preoperative and postoperative symptoms, complications, and postoperative satisfaction with surgery. RESULTS: Of the 204 procedures performed, 198 patients were either African American (24) or caucasian (174). Of the 18 African Americans undergoing laparoscopic antireflux surgery (LARS), five were converted to open and four had grade-1 or -2 complications. Of the 160 caucasians undergoing LARS, 27 were converted, and 17 had grade-1, -2, or -3 complications. African-American females had a heavier weight (222 lbs. versus 175 lbs., p<0.05) and conversion rate (55% versus 18%, p<0.05), compared to caucasian females. Satisfaction rates for African Americans were 88%, compared to 82% for caucasians. CONCLUSION: This study demonstrated significant differences between conversion rates in African Americans and caucasians with respects to frequency of surgery for GERD and conversion rates for LARS. Nevertheless, African Americans appear more satisfied with their surgical outcome. Further research is needed to determine whether African Americans truly have a lower incidence of GERD or if bias exists in referral patterns or cultural attitudes.     

Requirement for tumor necrosis factor receptor 2 expression on vascular cells to induce experimental cerebral malaria

Using tumor necrosis factor receptor type 2 (TNFR2)-deficient mice and generating bone marrow chimeras which express TNFR2 on either hematopoietic or nonhematopoietic cells, we demonstrated the requirement for TNFR2 expression on tissue cells to induce lethal cerebral malaria. Thus, TNFR2 on the brain vasculature mediates tumor necrosis factor-induced neurovascular lesions in experimental cerebral malaria.     

Changes in the nuclei of astrocytes following portacaval shunting and portacaval transposition in the rat.

Structural abnormalities are found in the astrocytes of the dentate nuclei of animals after portacaval shunting (PCS). These changes are also found in man in association with portal-systemic encephalopathy. To investigate the relationship between portal-systemic shunting and hepatocellular dysfunction in the pathogenesis of these changes, PCS and protacaval transposition (PCT) were performed in rats. PCT diverts portal blood into the systemic circulation, but retains normal total hepatic blood flow by perfusion with systemic venous blood. Liver function and mass are better preserved than after PCS. Abnormal glial cells were found in 4.03% of animals following sham operation, 13.45% following PCT, and 19.09% following PCS. Both experimental groups differed significantly from control animals, and the number of abnormal cells was significantly higher after PCS than after PCT. These findings are in keeping with the hypothesis that hepatocellular dysfunction plays an important role in addition to portal-systemic shunting in the aetiology of the structural changes in the brain associated with hepatic encephalopathy.     

Differential cytokine induction by doses of lipopolysaccharide and monophosphoryl lipid A that result in equivalent early endotoxin tolerance.

The phenomenon of early endotoxin tolerance, which is induced by sublethal injection of lipopolysaccharide (LPS), results in a protracted period of hyporesponsiveness that is most profound at 3 to 4 days after injection and is marked by reduced cytokine production after a challenge injection of LPS. Early endotoxin tolerance is also induced by the nontoxic LPS derivative monophosphoryl lipid A (MPL), although much more of the monophosphoryl derivative is required to produce a state of tolerance equivalent to that evoked by LPS. In this study, equivalent tolerance-inducing doses of LPS and MPL were tested, and the levels of cytokines induced by LPS and MPL were compared. Although induced levels of colony-stimulating factor were comparable following doses of LPS and MPL that elicited an equivalent state of early endotoxin tolerance, levels of tumor necrosis factor, interleukin-6, and interferon were significantly lower in MPL-injected animals. These results suggest that the lowered toxicity of MPL may be related to its elicitation of significantly lower levels of potentially toxic intermediaries such as tumor necrosis factor, interferon, and interleukin-6.     

Natural History of Mouse Syngeneic Lymphoma: Morphologic and Immunologic Aspects

The morphologic changes in lymphoreticular tissues and development of antitumor immune reactions of specific pathogen-free mice injected with syngeneic lymphoma cells were sequentially analyzed. The regional (right inguinal) lymph node demonstrated mild changes indicative of immunologic response. Systemic lymph nodes revealed a moderate degree of immune response on morphologic basis. The spleen was the site of marked activity, characterized by the presence of large pyroninophilic cells and germinal centers. Foci of necrosis in the local tumor accompanied by mature lymphocytes suggested cell-mediated immune rejection. Mice developed circulating antibodies 2 days after implantation. No antibodies were demonstrated attached to fresh tumor cells. Lymphocyte cytotoxic activity was demonstrated beginning on day 4. Both cytotoxic activity and circulating antibodies were no longer detectable after the third week following tumor implantation. Tumor-bearing mice also had an impaired capacity to mount a primary immune reaction to sheep red blood cells. The spleen demonstrated a marked loss of lymphocytes and the subsequent appearance of masses of amyloid material. It is suggested that amyloidosis in lymphoreticular organs is the result of a derangement in the immune response of the host following a prolonged and sustained antigenic stimulation. It appears that in syngeneic pathogen-free mice the spleen plays the major role in immune rejection mechanisms while the draining node only plays a modest role.