Antibody and memory B cell responses to the dengue virus NS1 antigen in individuals with varying severity of past infection

To further understand the role of NS1-specific antibodies (Abs) in disease pathogenesis, we compared neutralizing antibody levels (Nabs), NS1-Ab levels, IgG antibody subclass profiles and NS1-specific memory B-cell responses (Bmems) in individuals, with varying severity of past dengue. Nabs (Neut50 titres) were assessed using the Foci Reduction Neutralization Test (FRNT) and in-house ELISAs were used to assess NS1-Abs and NS1-Ab subclasses for all four DENV serotypes in individuals with past DF (n = 22), those with past DHF (n = 14) and seronegative (SN) individuals (n = 7). B-cell ELISpot assays were used to assess NS1-specific Bmem responses. 15/22 (68.18%) individuals with past DF and 9/14 (64.29%) individuals with past DHF had heterotypic infections. Neut50 titres were found to be significantly higher for DENV1 than DENV2 (p = 0.0006) and DENV4 (p = 0.0127), in those with past DHF, whereas there was no significant difference seen in titres for different DENV serotypes in those with past DF. Overall NS1-Ab to all serotypes and NS1-specific IgG1 responses for DENV1, 2 and 4 serotypes were significantly higher in those with past DHF than individuals with past DF. Those with past DHF also had higher IgG1 than IgG3 for DENV1 and DENV3, whereas no differences were seen in those with past DF. Over 50% of those with past DF or DHF had NS1-specific Bmem responses to >2 DENV serotypes. There was no difference in the frequency of Bmem responses to any of the DENV serotypes between individuals with past DF and DHF. Although the frequency of Bmem responses to DENV1 correlated with DENV1-specific NS1-Abs levels (Spearman r = 0.35, p = 0.02), there was no correlation with other DENV serotypes. We found that those with past DF had broadly cross-reactive Nabs, while those with past DHF had higher NS1-Ab responses possibly with a different functionality profile than those with past DF. Therefore, it would be important to further evaluate the functionality of NS1-specific antibody and Bmem responses to find out the type of antibody repertoire that is associated with protection against severe disease.     

Two novel factor V null mutations associated with activated protein C resistance phenotype/genotype discrepancy

Activated protein C (APC) resistance phenotype/genotype discrepancy is a very rare event. The objective of this study was to characterize the molecular mechanisms in two cases of APC phenotype/genotype discrepancy. An approach using direct sequencing of each exon and splicing junctions of the factor V gene showed that two novel factor V null mutations combined with heterozygous factor V Leiden mutation were responsible for this discrepancy. Our results suggest the necessity to use both phenotypic and genotypic analyses in some cases to determine an accurate diagnosis.     

HLA-class II alleles in Egyptian patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is linked to environmental, dietary, and life style factors. Its incidence and distribution vary widely among ethnic groups, sex, and geographic regions. HBV and HCV Infection, liver cirrhosis, male gender, and old age are important risk factors of HCC. Variability in outcome following exposure, and the clustering of HCC within families raise the possibility that genetic factors are also involved in susceptibility to HCC. The Major Histocompatibility Complex (MHC) plays a key role in anti-virus and tumor defense. HLA polymorphism is implicated in conferring genetic susceptibility to a large number of immune-mediated diseases, including some cancers. The association between HLA class II antigen and HCC in different ethnic populations that has been reported is controversial. Therefore, the aim of this work was to study the association between HLA class II-DRB1 and DQB1 polymorphism and HCC in Egyptian patients and to investigate their role as risk factors for the development of HCC. Methods: HLA-class II (DRB1 and DQB1) typing was done by SSP for 100 subjects; 50 patients suffering from HCC (45 males and 5 females) with age range 40-64 years (51.16 years (y) +/- 6.16); and 50 normal healthy control subjects. Results: 1. A significantly increased frequency of DRB1*04, and DQB1 *02 in HCC patients versus control group (p = 0.016, and 0.032, respectively) was found; 2. A significantly decreased frequency of DQB1*06 (p = 0.032) was found; 3. A significantly increased frequency of DRB1*07 (odds ratio (OR) = 4.929) was found; and 4. A significantly decreased frequency of DRB1*15 (OR = 0.316) was seen. In conclusion, while some alleles are significantly associated with HCC (DRB1*04, DQB1*02) and others are not associated (DQB1*06); therefore, it can be concluded that the DRB1*04 and DQB1*02 alleles might be risk factors for the occurrence of HCC (OR = 4.373 and 3.807, respectively), and DQB1*06 may be a protective allele (OR = 0.259).     

Tumor necrosis factor-α production from mononuclear cells in nephrotic syndrome

Tumor necrosis factor-alpha (TNF-alpha) levels in supernatant fluid from cultured peripheral blood mononuclear cells (PBMC) were measured by ELISA in 54 children with active non-inherited forms of primary nephrotic syndrome (PNS), 10 nephrotics in remission, and 10 healthy controls. Children with active PNS included 21 patients with steroid-sensitive (SS) minimal change nephrotic syndrome (MCNS), 5 patients with steroid-resistant (SR) MCNS, 11 with SR focal segmental glomerulosclerosis (FSGS), 6 patients with SS diffuse mesangial proliferation (DMP), 5 patients with SR DMP, and 6 patients with mesangiocapillary glomerulonephritis (MCGN). Patients with active PNS had elevated TNF-alpha production compared with controls. Remission was associated with normalization of TNF-alpha production. There was a positive correlation between TNF-alpha production and the degree of proteinuria ( r=0.34, P=0.013), mesangial hypercellularity ( r=0.42, P=0.028), and glomerulosclerosis ( r=0.46, P=0.001). By using ROC curve, TNF-alpha production greater or equal to a cut-off point of 50 pg/ml could be used to predict resistance to steroid therapy (predictability 93.2%). By discriminate analysis, TNF-alpha production could be used to discriminate between patients with SR MCNS, SR FSGS, and SR DMP (predictability 100%). In conclusion, TNF-alpha from cultured PBMC might be involved in the pathogenesis of proteinuria as well as the pathological changes that occur in non-inherited forms of PNS. TNF-alpha levels in PBMC culture could be used to predict the pathological type of PNS and the response of these patients to steroid therapy.     

Intraplaque hemorrhage: Its significance in cerebrovascular disease

Recently, carotid plaque factors, specifically intraplaque hemorrhage, have been studied with respect to the production of cerebrovascular symptoms. Ninety-five carotid endarterectomies were performed and the plaques that were removed were examined for intraplaque hemorrhage. Patients were separated into three groups: those with specific neurologic symptoms, those with nonlateralizing symptoms, and those who were asymptomatic. In the group of patients who presented with specific neurologic symptoms, correlation was made between the age of the intraplaque hemorrhage and the timing of symptoms.The vast majority of patients with specific neurologic symptoms exhibited carotid plaque hemorrhage, but patients with nonlateralizing symptoms and those who were asymptomatic also demonstrated an unexpectedly high percentage of intraplaque hemorrhage. Moreover, our results show a poor relationship between the timing of symptoms and the age of the intraplaque hemorrhage. These data do not refute the concept that intraplaque hemorrhage may play a role in the production of cerebrovascular symptoms, but they do refute the notion that the mere presence of hemorrhage causes specific neurologic symptoms and they also refute the previous report that demonstrates a good correlation between the timing of symptoms and the age of the intraplaque hemorrhage.     

Esophageal complications from combined chemoradiotherapy (cyclophosphamide + Adriamycin + cisplatin + XRT) in the treatment of non-small cell lung cancer

Esophageal complications from combined chemoradiotherapy (CCRT) were analyzed in 55 patients with limited non-small cell lung cancer. CCRT consisted of chemotherapy (cyclophosphamide, doxorubicin (Adriamycin), and cisplatin: CAP) and chest irradiation (5000 rad in 25 fractions/5 weeks). Forty-five patients received two courses of CAP, followed by five weekly courses of low dose CAP and irradiation followed by maintenance courses of CAP (Group 1). Ten patients received concomitant CCRT from the onset of treatment (Group 2). Esophagitis occurred in 80% of all patients. Severe esophagitis occurred in 27% of patients of Group 1 and 40% of patients of Group 2. Esophageal stricture or fistula developed in 1 of 45 (2%) patients in Group 1, and 3 of 10 (30%) patients in Group 2 (p less than 0.025). Weekly low-dose chemotherapy administered concomitantly with chest irradiation (R) at the onset of treatment significantly increases esophageal complications. A review of the literature suggests that CCRT may be used safely with split courses of R. The duration between onset of chemotherapy either before or after R should be greater than one week.     

Transcriptional repressor BCL-6 immortalizes germinal center-like B cells in the absence of p53 function

Chromosomal rearrangements in non-Hodgkin's B-cell lymphoma implicate BCL-6 as an oncogene, yet direct evidence for BCL-6 acting as an oncogene in B cells has been lacking. Here, we show that BCL-6 can immortalize primary B cells, but only in the absence of p53 tumor suppressor function. The expression of BCL-6 led to greatly increased B-cell proliferation, particularly in response to CD40 stimulation. Furthermore, BCL-6-infected p53-deficient B cells gave rise to immortalized cell lines that could be maintained by CD40 stimulation. We found that in primary mouse B cells, BCL-6 repressed expression of the Blimp-1, p27kip1, and cyclin D2 target genes. BCL-6 did not markedly repress the PDCD2 and BCL-XL target genes. The BCL-6 immortalized cell lines had a phenotype consistent with germinal center B cells, they expressed the germinal center-specific M17 gene, and a significant fraction of the cells stained positive with PNA. Our data indicate that BCL-6 may act to maintain B cells in a germinal center-like state, and repression of Blimp-1 by BCL-6 may be particularly crucial for stabilization of the germinal center phenotype. Our data also suggest that disruption of the p53 pathway may be crucial for the development of BCL-6-expressing B-cell lymphomas.     

Assessing CHD and hypertension in minority ethnic communities

Hypertension, coronary heart disease and stroke rates are higher in minority ethnic communities than their European counterparts. A health-needs assessment was undertaken to determine the prevalence of undiagnosed/asymptomatic hypertension among these communities in a primary care setting. Preliminary results indicate the prevalence to be 32.49 per cent. A number of strategies are discussed for improving the health care of minority ethnic communities and reducing health inequalities.     

Mechanical partial small bowel obstruction in a patient with Fitz-Hugh-Curtis syndrome

Perihepatitis or Fitz-Hugh-Curtis syndrome is a complication of pelvic inflammatory disease that usually leaves characteristic violin string adhesions on the anterior liver surface. These adhesions are common incidental findings on subsequent laparoscopy or laparotomy and are considered benign. We present a case of partial mechanical small bowel obstruction as a sequel of this syndrome that was diagnosed and treated laparoscopically.