Corrosion behaviour of heat treated boron free and boron containing Ti-13Zr-13Nb (wt%) alloy in simulated body fluid

The corrosion behaviour of heat treated Ti-13Zr-13Nb (TZN) and Ti-13Zr-13Nb-0.5B (TZNB) alloys in Hank's solution has been investigated. The microstructure of the heat treated TZN alloy consisted of α, β or martensite. Addition of boron to TZN alloy led to the formation of dispersed TiB particles and modification of microstructure. In general, the furnace cooled TZN sample showed lower corrosion potential (E(corr)) than the air cooled sample. Aging of water quenched samples decreased the E(corr) value. The passive current density of TZN samples varied within a narrow range. Presence of boron in TZN alloy decreased the corrosion potential and substantially increased the passive current density. Results showed that boron deteriorated the corrosion resistance of TZN alloy.

Alterations in the proteome of the NHERF2 knockout mouse jejunal brush border membrane vesicles

To identify additional potential functions for the multi-PDZ domain containing protein Na+/H+ exchanger regulatory factor 2 (NHERF2), which is present in the apical domain of intestinal epithelial cells, proteomic studies of mouse jejunal villus epithelial cell brush border membrane vesicles compared wild-type to homozygous NHERF2 knockout FVB mice by a two-dimensional liquid chromatography-tandem mass spectrometry (LC-MS/MS)-iTRAQ approach. Jejunal architecture appeared normal in NHERF2 null in terms of villus length and crypt depth, Paneth cell number, and microvillus structure by electron microscopy. There was also no change in proliferative activity based on BrdU labeling. Four brush border membrane vesicles (BBMV) preparations from wild-type mouse jejunum were compared with four preparations from NHERF2 knockout mice. LC-MS/MS identified 450 proteins in both matched wild-type and NHERF2 null BBMV; 13 proteins were changed in two or more separate BBMV preparations (9 increased and 4 decreased in NHERF2 null mice), while an additional 92 proteins were changed in a single BBMV preparation (68 increased and 24 decreased in NHERF2 null mice). These proteins were categorized as 1) transport proteins (one increased and two decreased in NHERF2 null); 2) signaling molecules (2 increased in NHERF2 null); 3) cytoskeleton/junctional proteins (4 upregulated and 1 downregulated in NHERF2 null); and 4) metabolic proteins/intrinsic BB proteins) (2 upregulated and 1 downregulated in NHERF2 null). Immunoblotting of BBMV was used to validate or extend the findings, demonstrating increase in BBMV of NHERF2 null of MCT1, coronin 3, and ezrin. The proteome of the NHERF2 null mouse small intestinal BB demonstrates up- and downregulation of multiple transport proteins, signaling molecules, cytoskeletal proteins, tight junctional and adherens junction proteins, and proteins involved in metabolism, suggesting involvement of NHERF2 in multiple apical regulatory processes and interactions with luminal contents.

Role of pulmonary infection in the development of chronic lung disease of prematurity

We studied the role of ante- and post-natal infection in the development of chronic lung disease (CLD) of prematurity. 192 newborn infants (61 term and 131 pre-term of <34 weeks gestation: 88 with respiratory distress syndrome, 35 developed CLD and eight died) were recruited. 16S ribosomal RNA (rRNA) genes were identified by PCR of DNA isolated from 840 gastric and lung fluid samples. Ureaplasma spp. were also cultured. Presence of 16S rRNA genes (OR 1.6, 95% CI 1.2-2.2) and Ureaplasma spp. (OR 3.6, 95% CI 1.7-7.7) was significantly associated with the development of CLD. This association remained if the 16S rRNA genes and Ureaplasma spp. were first identified within the first 3 days of life (OR 2.4 (95% CI 1.4-4.1) and 3.8 (95% CI 1.4-10.0), respectively) or if first identified after 3 days of age (OR 1.7 (95% CI 1.1-2.8) and OR 5.1 (95% CI 1.3-19.8), respectively). Peak lung fluid interleukin (IL)-6 and IL-8 were significantly associated with presence of microbes (p<0.0001 and p=0.0001, respectively) and development of CLD (p=0.003 and 0.001, respectively). Both early and late microbial presence in neonatal lung fluid samples was significantly associated with the development of CLD suggesting that both ante- and post-natal infection play a role in the development of CLD.

Alterations in the proteome of the NHERF1 knockout mouse jejunal brush border membrane vesicles

Na/H exchanger regulatory factor 1 (NHERF1) is a scaffold protein made up of two PDZ domains and an ERM binding domain. It is in the brush border of multiple epithelial cells where it modulates 1) Na absorption by regulating NHE3 complexes and cytoskeletal association, 2) Cl secretion through trafficking of CFTR, and 3) Na-coupled phosphate absorption through membrane retention of NaPi2a. To further understand the role of NHERF1 in regulation of small intestinal Na absorptive cell function, with emphasis on apical membrane transport regulation, quantitative proteomic analysis was performed on brush border membrane vesicles (BBMV) prepared from wild-type (WT) and homozygous NHERF1 knockout mouse jejunal villus Na absorptive cells. Jejunal architecture appeared normal in NHERF1 null; however, there was increased proliferative activity, as indicated by increased crypt BrdU staining. LC-MS/MS analysis using iTRAQ to compare WT and NHERF1 null BBMV identified 463 proteins present in both WT and NHERF1 null BBMV of simultaneously prepared and studied samples. Seventeen proteins had an altered amount of expression between WT and NHERF1 null in two or more separate preparations, and 149 total proteins were altered in at least one BBMV preparation. The classes of the majority of proteins altered included transport proteins, signaling and trafficking proteins, and proteins involved in proliferation and cell division. Affected proteins also included tight junction and adherens junction proteins, cytoskeletal proteins, as well as metabolic and BB digestive enzymes. Changes in abundance of several proteins were confirmed by immunoblotting [increased CEACAM1, decreased ezrin (p-ezrin), NHERF3, PLCβ3, E-cadherin, p120, β-catenin]. The changes in the jejunal BBMV proteome of NHERF1 null mice are consistent with a more complex role of NHERF1 than just forming signaling complexes and anchoring proteins to the apical membrane and include at least alterations in proteins involved in transport, signaling, and proliferation.

Needle sticks injury among nurses involved in patient care: a study in two medical college hospitals of West Bengal

A hospital-based retrospective study on a sample of 228 nurses involved in patient care, in two medical college hospitals of West Bengal, showed that 61.4% of them sustained at least one Needle Stick Injury (NSI) in last 12 months. The risk of such injuries per 1000 nurses per year was found to be 3,280. Out of the most recent injuries among 140 nurses, 92.9% remained unreported to appropriate authorities; in 52.9% events hand gloves were worn by the nurses; only 5% of those nurses received hepatitis B vaccine, 2.1% hepatitis B immunoglobulin and none of them received post exposure prophylaxis for HIV.

Septic abortions: a descriptive study in a teaching hospital at North Bengal, Darjeeling

A hospital based cross sectional study for one year done among 57 diagnosed and admitted septic abortion cases, revealed that 71.9% septic abortions were performed by untrained persons, 63.2% mothers were illiterate, 22.8% mothers were in adolescent age group. Exploratory Laparotomy was needed in 46.3% cases and important complications for referring were severe anaemia and septic shock.

In vivo enhancement of nucleopolyhedrovirus of oriental Armyworm, Mythimna separata using spindles from Helicoverpa armigera entomopoxvirus

When the third instar larvae of M. separata were exposed to eight varying concentrations of polyhedral occlusion bodies (POB's) of nucleopolyhedrovirus of M. separata (MsNPV) ranging from 2.6 x 10(-1) to 2.6 x 10(8) POB's/ml, the percent mortality and incubation period ranged from 16-100% and 14 to 9 days respectively. On the other hand when the same third instar larvae of M. separata were exposed to only five varying concentration of POB's of MsNPV ranging from 2.6 x 10(2) to 2.6 x 10(6), POB's/ml along with a constant dose of entomopox viral spindles from Helicoverpa armigera, the per cent mortality ranged from 63 to 100% with reduction in incubation period from 7 to 4 days respectively. The enhancement index (log10) of the virus was 2.76 or reduction of more than 500 times in LC50. The ability and the mechanism of the spindles from H. armigera entomopoxvirus to enhance the infectivity of MsNPV has been discussed.

Par-4 drives trafficking and activation of Fas and Fasl to induce prostate cancer cell apoptosis and tumor regression

Prostate cancer cells are generally resistant to apoptosis by conventional therapy. During a search for molecules that may overcome prostate cancer cell survival mechanisms, we identified the prostate apoptosis response-4 (Par-4) gene. Par-4 induced apoptosis of selective prostate cancer cells PC-3, DU-145, and TSU-Pr and caused tumor regression by inhibition of NF-kappaB activity and cell membrane trafficking of Fas and FasL that leads to the activation of the Fas-Fas-associated death domain-caspase-8 pro-death pathway. Neither Fas pathway activation alone nor inhibition of NF-kappaB activity with IkappaB-super repressor was sufficient to induce apoptosis of prostate cancer cells. Coregulation of these two pathways was essential and sufficient for Par-4 to induce apoptosis. On the other hand, prostate cancer cells LNCaP or normal prostatic epithelial cells that were resistant to apoptosis by Par-4 did not show Fas or FasL trafficking. These findings identify a mechanism of apoptosis by Par-4 and suggest that Par-4 may have therapeutic potential.

Beneficial effects of continuous subcutaneous insulin infusion in older patients with long-standing type 1 diabetes

OBJECTIVE

To assess the effect of continuous subcutaneous insulin infusion (CSII) on glycemic control, hypoglycemia, and daily insulin requirements in five older patients with long-standing type 1 diabetes previously treated with multiple-dose insulin injections (MDII).

METHODS

We undertook a retrospective analysis of five older patients (three women and two men) with type 1 diabetes and a mean age of 66.4 years (range, 57 to 76). The mean duration of disease was 33 years (range, 18 to 49), and all patients had suboptimal glycemic control (glycosylated hemoglobin or HbA(1c) >8.0%), presence of microvascular complications, and unacceptably frequent hypoglycemia during MDII therapy. A diabetes care team monitored their clinical course after their treatment was changed to a CSII regimen. Data pertaining to HbA(1c), severe hypoglycemia, and insulin dose before and after conversion to CSII were compared with use of paired t tests.

RESULTS

After initiation of CSII therapy, the mean HbA(1c) value decreased from 9.16% to 7.6% (P<0.0025), the rate of severe hypoglycemia decreased from 3.2 episodes to 0.4 episode per year (P<0.02), and the mean total daily insulin dose was reduced from 44.9 IU to 32.4 IU (P<0.05) during a mean duration of 12.6 months of CSII therapy.

CONCLUSION

Insulin pump therapy can prove highly beneficial in older patients with type 1 diabetes by improving glycemic control, reducing hypoglycemic episodes and insulin dosage, and possibly increasing treatment satisfaction. These changes can potentially prevent morbidity and prove to be cost-effective. For implementation of pump conversion to be safe and successful, careful patient selection, proper education, and ongoing support through a comprehensive diabetes education and management program are imperative. Future reports of experience with CSII in elderly patients should help to elucidate its promising advantages in this patient population and provide guidelines for use.

Increased risk of antituberculosis drug-induced hepatotoxicity in individuals with glutathione S-transferase M1 'null' mutation

BACKGROUND

Pathogenesis and genetic factors influencing predisposition to antituberculosis drug (ATD)-induced hepatotoxicity are not clear. Polymorphism at the genetic locus of a drug and xenobiotic compound metabolizing enzyme, N-acetyltransferase type 2 (NAT2), is reported to be associated with the excess generation of toxic reactive metabolites. Polymorphisms at the glutathione S-transferase (GST) loci (GSTM1 and GSTT1) are involved in the detoxification of these toxic metabolites in the human body to a lesser extent. We have examined whether polymorphisms at these loci are associated with the risk of ATD-induced hepatotoxicity.

METHODS

In this case-control study, 33 pulmonary tuberculosis patients with ATD-induced hepatotoxicity and 33 pulmonary tuberculosis patients receiving ATD drugs without any evidence of hepatotoxicity were considered as cases and controls, respectively. Point mutations at NAT2 and homozygous 'null' mutations at GSTM1 and GSTT1 genes were looked into genomic DNA, isolated from peripheral blood mononuclear cells by using polymerase chain reaction (PCR).

RESULTS

The frequency of homozygous 'null' mutation at the GSTM1 gene was significantly higher among cases (n = 17, 52%) than controls (n = 8, 24%) (P < 0.05, relative risk 2.13, 95% CI: 1.25-3.10). Frequencies of mutations at GSTT1 and NAT2 genes did not differ significantly between cases and controls.

CONCLUSION

Homozygous 'null' mutation at the GSTM1 gene might predispose an individual to ATD-induced hepatotoxicity.

Ethnic differences in distributions of GSTM1 and GSTT1 homozygous "null" genotypes in India

We estimated the frequencies of GSTM1 and GSTT1 "null" homozygotes in 10 different ethnic populations of India by a genotyping method based on polymerase chain reaction. These populations, inhabiting diverse geographical locations and occupying various positions in the sociocultural hierarchy, were represented by a sample of 299 unrelated individuals. Frequencies of GSTM1 and GSTT1 "null" homozygotes varied from 20% to 79% and 3% to 39%, respectively, across the study populations. Maximum frequencies of GSTM1 and GSTT1 "null" homozygotes (79% and 39%, respectively) have been observed in the same population (Jamatia). Frequencies of homozygous "null" genotypes at the GSTM1 and GSTT1 loci show a significant positive correlation in these populations, which is contrary to expectations. A possible implication is that the two enzymes are working in tandem, instead of working in a complementary way.

Coupling of nerve growth factor to its receptor: inhibition by anti-GM3 ganglioside antibody

1. Normal differentiation of PC 12 cells and dorsal root ganglionic neurons in culture need nerve growth factor (NGF) for their neurite outgrowth. 2. An antibody against GM3 ganglioside was found to inhibit the nerve growth factor mediated neurite formation of both the cells in vitro significantly. 3. Further analysis revealed that the binding of 125I-NGF to live PC 12 cells could be markedly inhibited by anti-GM3 antibody in a dose dependent manner. 4. Scatchard analysis revealed that in the presence of anti-GM3 antibody only some low affinity binding sites were available for NGF-high affinity binding sites were totally blocked. 5. These results further strengthen the hypothesis that anti-GM3 antibody affects neuronal cell growth by interfering with the coupling of growth factors to their cell surface receptors.

Clinical and immune responses in resected colon cancer patients treated with anti-idiotype monoclonal antibody vaccine that mimics the carcinoembryonic antigen

PURPOSE

We generated an anti-idiotype antibody, designated CeaVac, that is an internal image of the carcinoembryonic antigen (CEA). We previously demonstrated that the majority of patients with advanced colorectal cancer generate specific anti-CEA responses. The purpose of the current study was to treat patients with surgically resected colon cancer with CeaVac to determine the immune response and clinical outcome to treatment with vaccine. We also compared the immune responses between patients treated with fluorouracil (5-FU) chemotherapy regimens plus vaccine versus vaccine alone.

PATIENTS AND METHODS

Thirty-two patients with resected Dukes' B, C, and D, and incompletely resected Dukes' D disease were treated with 2 mg of CeaVac every other week for four injections and then monthly until tumor recurrence or progression. Fourteen patients were treated concurrently with 5-FU chemotherapy regimens.

RESULTS

All 32 patients entered onto this trial generated high-titer immunoglobulin G and T-cell proliferative immune responses against CEA. The 5-FU regimens did not have a qualitative or quantitative effect on the immune response. Three of 15 patients with Dukes' B and C disease progressed at 19, 24, and 35 months. Seven of eight patients with completely resected Dukes' D disease remained on study from 12 to 33 months; one patient with resected Dukes' D disease relapsed at 9 months. One patient with incompletely resected Dukes' D disease remained on study at 14 months without evidence of progression; eight experienced disease progression at 6 to 31 months.

CONCLUSION

CeaVac consistently generated a potent anti-CEA humoral and cellular immune response in all 32 patients entered onto this trial. A number of very high-risk patients continue on study. 5-FU regimens, which are the standard of care for patients with Dukes' C disease, did not affect the immune response. These data warrant a phase III trial for patients with resected colon cancer.