Scavenger receptors in innate immunity.

Scavenger receptors (SR) are expressed by myeloid cells (macrophages and dendritic cells) and certain endothelial cells. They play an important role in uptake and clearance of effete components, such as modified host molecules and apoptotic cells. They bind and internalise micro-organisms and their products including Gram-positive bacteria (lipoteichoic acid), Gram-negative bacteria (lipopolysaccharide), intracellular bacteria and CpG DNA. SR can alter cell morphology and their expression is affected by various cytokines. SR are involved in lipid metabolism and bind modified low-density lipoproteins.     

Sonochemically prepared BSA microspheres containing Gemcitabine,and their potential application in renal cancer therapeutics

This report demonstrates the formation and characterization of sonochemically prepared bovine serum albumin (BSA)–Gemzar (Gemcitabine) microspheres and shows their increased anticancer activity compared to pristine Gemzar. The amount of loaded Gemzar was determined by light absorption measurements. The BSA–Gemzar composite was analyzed and characterized by optical microscopy and scanning electron microscopy. The release kinetics of Gemzar from the proteinaceous microspheres was tested. The BSA–Gemzar composite was examined for its anticancer activity (in vitro) in renal cancer cells (RCC, 786-O cells) using [³H]thymidine incorporation assays. It was found that the influence of the Gemzar-loaded microspheres on the cancer cells was significantly greater than that of an equimolar concentration of pristine Gemzar.     

Sequencing and Functional Annotation of Avian Pathogenic Escherichia coli Serogroup O78 Strains Reveal the Evolution of E. coli Lineages Pathogenic for Poultry via Distinct Mechanisms

Avian pathogenic Escherichia coli (APEC) causes respiratory and systemic disease in poultry. Sequencing of a multilocus sequence type 95 (ST95) serogroup O1 strain previously indicated that APEC resembles E. coli causing extraintestinal human diseases. We sequenced the genomes of two strains of another dominant APEC lineage (ST23 serogroup O78 strains χ7122 and IMT2125) and compared them to each other and to the reannotated APEC O1 sequence. For comparison, we also sequenced a human enterotoxigenic E. coli (ETEC) strain of the same ST23 serogroup O78 lineage. Phylogenetic analysis indicated that the APEC O78 strains were more closely related to human ST23 ETEC than to APEC O1, indicating that separation of pathotypes on the basis of their extraintestinal or diarrheagenic nature is not supported by their phylogeny. The accessory genome of APEC ST23 strains exhibited limited conservation of APEC O1 genomic islands and a distinct repertoire of virulence-associated loci. In light of this diversity, we surveyed the phenotype of 2,185 signature-tagged transposon mutants of χ7122 following intra-air sac inoculation of turkeys. This procedure identified novel APEC ST23 genes that play strain- and tissue-specific roles during infection. For example, genes mediating group 4 capsule synthesis were required for the virulence of χ7122 and were conserved in IMT2125 but absent from APEC O1. Our data reveal the genetic diversity of E. coli strains adapted to cause the same avian disease and indicate that the core genome of the ST23 lineage serves as a chassis for the evolution of E. coli strains adapted to cause avian or human disease via acquisition of distinct virulence genes.     

Cholera Toxin Production by the El Tor Variant of Vibrio cholerae O1 Compared to Prototype El Tor and Classical Biotypes

Vibrio cholerae O1 El Tor variant strains produced much more cholera toxin than did prototype El Tor strains. The amount of cholera toxin produced by El Tor variant strains both in vitro and in vivo was more or less equivalent to that produced by classical strains.Vibrio cholerae O1 is classified into classical and El Tor biotypes. Among other genetic, biochemical, and physiological differences, each biotype has unique gene sequences encoding cholera toxin B subunit (CTB), that is, classical ctxB and El Tor ctxB. Besides these two prototype biotypes of V. cholerae O1, Nair et al. (9) in 2002 in Bangladesh isolated strains that possess phenotypic properties of both classical and El Tor biotypes carrying classical ctxB. The same group also isolated El Tor strains that had classical ctxB (10). For these new types of strains of V. cholerae O1, we have recently proposed the designations of hybrid and El Tor variants, respectively (13). Subsequent to the isolation of the El Tor variant in Bangladesh by Nair et al. (10), El Tor variant strains were isolated from several countries and areas in Asia and Africa (1, 11, 15-18). In Kolkata, India, we showed that El Tor variant strains appeared in 1990 and that a complete replacement of prototype El Tor strains by El Tor variant strains has occurred since 1995 (14).In this study, we investigated the amount of cholera toxin (CT) produced both in vitro and in vivo by V. cholerae O1 El Tor variant strains isolated in Kolkata during a period from 1996 to 2007. It was found that El Tor variant strains produced a much larger amount of CT than did prototype El Tor strains and that the amount of CT produced by El Tor variant strains was more or less equivalent to that produced by classical strains.V. cholerae O1 strains used in this study are listed in Table ​Table1.1. AKI (3) and Syncase medium (2) were used for culturing the test strains. The rationale for selecting these media was that AKI preferentially supports the production of El Tor CT (3) while Syncase medium is reported to be the best medium supporting the production of CT by the classical biotype (2). Measurement of CT concentration produced by V. cholerae O1 strains was carried out as follows. Each strain was cultured either in AKI medium at 37°C for 20 h without shaking or in Syncase medium at 37°C for 20 h with shaking, and the optical density of the culture was measured at 600 nm (OD₆₀₀). After centrifugation, the supernatants were collected and the concentration of CT (ng/ml/OD₆₀₀) in the samples was measured by bead enzyme-linked immunosorbent assay (ELISA). The method of the bead ELISA employed was essentially that described by Oku et al. (12). In brief, a polystyrene bead (6.5 mm in diameter) was coated with anti-CT IgG and used as a solid phase. The coated bead was first incubated with the sample and then incubated with anti-CT IgG [F(ab′)]-horseradish peroxidase conjugate. Peroxidase activity was determined colorimetrically with 3,3′,5,5′-tetramethylbenzidine as the substrate. The absorbance at 450 nm (OD₄₅₀) was linear between 0 and 0.5, representing CT concentrations of 0 to 20 ng/ml. The sample prepared as described above (the supernatant of the culture of the strain) was appropriately diluted so that the OD₄₅₀ fell in the range of 0.1 to 0.5, and the amount of CT produced by the strain was expressed as ng/ml/OD₆₀₀.

TABLE 1.

V. cholerae O1 strains used

Lack of significant association between -1021C-->T polymorphism in the dopamine beta hydroxylase gene and attention deficit hyperactivity disorder

Recent trends in medications for attention deficit hyperactivity disorder (ADHD) suggest that norepinephrine (NE) deficiency may contribute to the disease etiology. Dopamine beta hydroxylase (DBH) is the key enzyme which converts dopamine to NE and since DBH gene is considered a major quantitative trait locus for plasma DBH activity, genetic polymorphism may lead to altered NE neurotransmission. Several polymorphisms including a 5' flanking -1021C-->T polymorphism, was reported to be associated with changed DBH activity and an association between -1021C-->T polymorphism with ADHD was observed in Han Chinese children. We have carried out family-based studies with three polymorphisms in the DBH gene, -1021C-->T polymorphism, exon 2*444g/a and intron 5 TaqI RFLP, to explore their association with Indian ADHD cases. Allele and genotype frequency of these polymorphisms in ADHD cases were compared with that of their parents and a control group. Haplotypes obtained were analyzed for linkage disequilibrium (LD). Haplotype-based haplotype relative risk analysis and transmission disequilibrium test showed lack of significant association between transmission of the polymorphisms and ADHD. A haplotype comprising of allele 1 of all polymorphisms showed a slight positive trend towards transmission from parents to ADHD probands. Strong LD was observed between *444g/a and TaqI RFLP in all the groups. However, low D' values and corresponding log of odds scores in the control group as compared to the ADHD families indicated that, the incidence of the two polymorphisms being transmitted together could be higher in ADHD families.     

The role of omental biopsy in endometrial cancer staging

Omental biopsy is not part of FIGO staging for endometrial cancer. The few studies that have looked into this matter have had conflicting results. This is the largest study in terms of the number of cases studying the incidence of omental involvement in endometrioid and non-endometrioid endometrial cancer. A retrospective study assessing 248 cases of endometrial cancer with omental biopsy at the time of primary surgical treatment for endometrial cancer at the Gynaecological Oncology Centre, Norfolk and Norwich University Hospital between January 2004 and May 2008. Demographic, clinico-pathologic and surveillance data were collected from hospital records, operative notes and histopathology results. The histology included tumour type, stage, grade and omental biopsy. All histological types were included in the study. Two hundred and forty eight patients had an omental biopsy at the time of primary surgical treatment for endometrial cancer during the study period. Of them, 187 cases were stage I, 27 stage II, 27 stage III and seven stage IV. According to histological type, 202 (81.4%) had endometrioid, 20 (8.0%) serous papillary, 20 (8.0%) malignant mixed Mullerian tumour (MMMT), three (1.2%) clear cell and three (1.2%) sarcoma. Overall, six cases (2.4%) had omental involvement, 4/202 (1.98%) with endometrioid type, 1/20 (5.0%) with serous papillary type and 1/20 (5.0%) MMMT. Eighty four percent of omental metastases (five cases) were macroscopic and noted at operation .The overall risk of omental metastases is 2.4% and in the absence of gross lesions the risk is around 0.4%. Most omental metastases can be diagnosed by careful inspection and palpation of the omentum. The possibility of missing microscopic disease is low. Based on these figures and possible increase in morbidity and operative time, omental biopsy cannot be justified as a standard procedure in endometrial cancer staging.     

Left ventricular function in isolated rheumatic mitral stenosis in children

A total of 18 patients with pure rheumatic mitral stenosis between the ages of eight and 14 years (average 11.8 years) were studied. Left ventricular angiograms in the right anterior oblique view were obtained in each. Moderate to severe pulmonary arterial hypertension was present in all but one. The mean left ventricular end-systolic volume index was 25.4 +/- 8.5 ml/m2; it was increased in five patients. The mean left ventricular end-diastolic volume index was 64 +/- 13.5 ml/m2. It was normal in all except one patient, in whom it was increased to 91 ml/m2. The left ventricular stroke volume index, 39.6 +/- 8.8 ml/m2, was within the normal range. The left ventricular stroke volume index, 39.6 +/- 8.8 ml/m2, was within the normal range. The mean left ventricular ejection fraction was 0.61 +/- 0.09 ml, with a range of 0.44-0.72. The mean left ventricular ejection fraction was lower than normal (P less than 0.05). The ejection fraction was low in five of the 18 patients. Four of the five patients with an ejection fraction below 0.60 had severe pulmonary arterial hypertension. There was no correlation between the ejection fraction and left atrial pressure or the mitral valve area. Segmental contraction analysis in the five patients with a low ejection fraction showed global hypokinesia in four and segmental hypokinesia, involving predominantly the posterobasal segment, in one patient. Our study suggests that even children with pure mitral stenosis may have left ventricular dysfunction in the absence of active carditis.     

Blood-aqueous barrier in prostaglandin EP2 receptor knockout mice

The role of prostaglandin EP(2) receptors in the disruption of the blood-aqueous barrier was examined using EP(2) receptor-deficient mice. Eyes were topically treated with EP receptor agonists or subjected to paracentesis. Fluorescein angiography was performed after topical treatment with 2.0 icrog butaprost. The results show that EP receptor agonists, PGE( 2) and the EP(2) receptor-selective agonist butaprost, increased aqueous humor protein in EP(2) +/+ wild-type mice to 18.0 mg/ml and 12.0 mg/ml, respectively, from the control value of 2.7 mg/ml. The increase in aqueous humor protein concentration in response to these EP receptor agonists was reduced significantly in EP(2) receptor-deficient mice. Fluorescein leakage into the anterior chamber, two minutes after its injection, was significantly greater in butaprost-treated wild-type mice than in butaprost-treated knockout mice. Protein concentration, 15 min after paracentesis, increased from 2.2 mg/ml to 25.0 mg/ml in the aqueous humor of the eyes of wild-type mice, while the increase in knockout mice was 10.6 mg/ml. These results suggest that EP( 2) and EP(4) receptors mediate the disruption of the blood-aqueous barrier induced by EP receptor agonists and paracentesis.