Mechanical and Abrasive Wear Performance of Titanium Di-Oxide Filled Woven Glass Fibre Reinforced Polymer Composites by Using Taguchi and EDAS Approach

Two-body abrasive wear behavior of glass fabric reinforced (GC) epoxy and titanium dioxide (TiO₂) filled composites have been conducted out by using a tribo test machine. GC and TiO₂ filled GC composites were produced by the hand layup technique. The mechanical performances of the fabricated composites were calculated as per ASTM standards. Three different weight percentages were mixed with the polymer to develop the mechanical and abrasive wear features of the composites. Evaluation Based on Distance from Average Solution (EDAS), a multi-criteria decision technique is applied to find the best filler content. Based on the output, 2wt% TiO₂ filler gave the best result. Abrasive wear tests were used to compare GC and TiO₂ filled GC composites. The abrasion wear mechanisms of the unfilled and TiO₂ filled composites have also been studied by scanning electron microscopy. The outcome of the paper suggests the correct proportion of filler required for the resin in order to improve the wear resistance of the filled composites. Taguchi combined with Multi-Criteria Decision Method (MCDM) is used to identify the better performance of the TiO₂ filled epoxy composites.     

Chemopreventive effect of Ocimum sanctum on DMBA-induced hamster buccal pouch carcinogenesis

Ocimum sanctum L., a plant having multi-medicinal properties, has been investigated for its chemopreventive activity against 7,12-dimethylbenz (a) anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. O. sanctum, in the form of fresh leaf paste, aqueous extract and ethanolic extract were topically applied and the extracts were orally administered to buccal pouch mucosa of animals exposed to 0.5% of DMBA. Incidence of papillomas and squamous cell carcinomas were significantly reduced, and increased the survival rate in the topically applied leaf paste and orally administered extracts to animals. Among them, the orally administered aqueous extract showed profound effect than the other two forms. Histopathological observations made on the mucosa confirmed these findings. Further fluorescent spectral studies at 405 nm excitation on the mucosa of control, DMBA and extracts orally administered experimental animals showed a prominent maxima at 430 nm for control, 628 nm for DMBA induced carcinomas while aqueous and ethanolic extracts administered animals showed at 486 nm and 488 nm, respectively. The fluorescent intensity at 630 nm (FI630 nm) was significantly reduced and the ratio of fluorescent intensities at 520 nm and 630 nm (FI520 nm/630 nm) were significantly increased in orally administered extracts compared to DMBA treated animals. These observations suggest that the orally administered extract of O. sanctum may have the ability to prevent the early events of carcinogenesis.     

Tissue microarray detection of matrix metalloproteinases, in diseased tricuspid and bicuspid aortic valves with or without pathology of the ascending aorta

Objective: The degeneration of bicuspid aortic valve and its frequent association with ascending aortic pathology, point to a still unidentified genetic tissue defect with unknown mediators. Metalloproteinases (MMPs) are lytic enzymes that have been strongly implicated in aneurysm formation. The purpose of this study was to detect the presence of these enzymes in aortic valvular tissue in healthy and diseased aortic valves with or without the presence of synchronous ascending aortic pathology. Methods: Aortic valve specimens from 26 aortic valve replacement patients as well as 4 healthy control tricuspid aortic valves were included. 10 patients had bicuspid aortic valves, and 16 had tricuspid aortic valves. Half of our patient population had a concomitant aortic procedure for aortic pathology. The study detected MMPs 1,2 and 9 as well as their Tissue inhibitors (TIMPs) 1 and 2. MMP and TIMP detection was accomplished with the construction of a tissue micro array and immunohistochemistry. Conclusions: MMP-9 expression was significantly higher in bicuspid aortic valves compared to normal valves (P<0.05). When compared to the tricuspid valve group, MMP-9 mean value was significantly higher in bicuspid valves (P<0.05).When the entire rest of the valve group (n=4+16, i.e. control and tricuspid valve groups) was compared to the bicuspid valve group, bicuspid valves had significantly higher MMP-2, and MMP-9 (P<0.01) expression. TIMP expression also changed in diseased valves, among different patient groups. This increased proteolytic presence in bicuspid aortic valves may attribute to the observed decreased elastin and collagen content, and their resultant functional failure.     

Extended lymph node dissection (D2 resection) should now be performed routinely in the curative surgical treatment of gastric carcinoma.

Gastric cancer has a dismal prognosis in the Western world. In contrast, in Japan where extended lymphadenectomy is the rule in curative gastric cancer surgery, the prognosis is much better. The arguments for and against the adoption of this procedure in the West are presented. This procedure is safe in the hands of experienced surgeons and by improving locoregional control, may improve survival. However, in the absence of controlled data supporting a survival advantage, the excess morbidity and mortality of this extended procedure in the West may not be justified.     

Intraventricular B-cell lymphoma from the breast

We report an unusual case of massive intraventricular spread of B-cell lymphoma of the breast, presenting with rapidly progressive ataxia and impaired cognition with need for ventriculostomy. Rapid resolution followed intravenous dexamethasone and radiation therapy. Received: 20 August 1996 Accepted: 14 January 1998     

Role of Shc in T-cell development and function

Shc is a prototype adapter protein that is expressed from the earliest stages of T‐cell development. Shc becomes rapidly tyrosine phosphorylated after T‐cell receptor (TCR) engagement. Expression of dominant negative forms of Shc in T‐cell lines had also suggested a role for this adapter downstream of the TCR. However, until recently, the relative significance of Shc compared to several other adapters in T cells was unclear. Mice lacking Shc expression specifically in the T‐cell lineage together with inducible expression of dominant negative Shc in transgenic mice have revealed an essential and nonredundant role for Shc in thymic T‐cell development. Functional defects in a Jurkat T‐cell line lacking Shc expression also suggest a role for Shc in mature T‐cell functions. While the requirement of Shc in T‐cell signaling is now established, precisely what signaling pathways downstream of Shc make this adapter unique are less clear. Although the Shc‐mediated activation of the extracellular signal regulated kinase (Erk)/mitogen‐activated protein kinase (MAPK) pathway could be one component, Shc likely signals to other pathways in T cells that are not yet discovered. A better molecular understanding of Shc function in the future could provide insights into how multiple adapters coordinate the various outcomes downstream of the TCR.     

Impact of neonatal hypothyroidism on Leydig cell number, plasma, and testicular interstitial fluid sex steroids concentration.

We have previously demonstrated that neonatal and transient neonatal hypothyroidism modulates Leydig, Sertoli, and germ cell numbers, sex steroids and androgen binding protein concentration. The present study was undertaken to study the effect of neonatal onset hypothyroidism on Leydig and peritubular myoid cell numbers, plasma and testicular interstitial fluid (TIF) sex steroid concentration at different age groups of Wistar rats. Hypothyroidism was induced by giving 0.05% methimazole (MMI) to lactating mothers or directly to the male pups from day 1 postpartum through days 10, 15, 30, 40 and 60 postpartum. To confirm hypothyroidism, plasma thyroid hormones and TSH were assayed. Plasma and TIF testosterone, progesterone, dihydrotestosterone (DHT) and estradiol were assayed by radioimmunoassay. Leydig cell number in hypothyroid rats were less than the age-matched controls. The diameter of Leydig cells in hypothyroid rats was smaller than the controls but 10 days old hypothyroids alone had larger than control rats. A significant decrease of peritubular myoid cell number was observed in 30, 40 and 60 days hypothyroid rats and increased in 10 and 15 days hypothyroidism. Hypothyroid rats had elevated level of plasma LH and decreased GH (except day 10 postpartum). Plasma PRL level was increased in 10 and 15 days hypothyroid rats and an opposite effect was observed in 40 and 60 days hypothyroidism. Plasma testosterone, DHT and estradiol were decreased in all hypothyroid rats. However, plasma progesterone level in hypothyroid rats was significantly higher at days 10, 30, and 40 postpartum and an opposite effect was seen in 15 and 60 days experimental groups. TIF testosterone and progesterone titre showed a consistent decrease in hypothyroid rats irrespective of the duration. In hypothyroid rats, TIF DHT levels decreased significantly in days 10, 40 and 60 postpartum. However, it increased in days 15 and 30 postpartum. Except at day 10 postpartum, the level of TIF estradiol in hypothyroid rats was significantly less than their age matched controls. Our data clearly indicate that neonatal onset hypothyroidism adversely affect Leydig cell proliferation along with impaired steroidogenesis.     

Lateral ventricular enlargement and clinical response in schizophrenia

The relationship between enlargement of the lateral ventricles in the brains of schizophrenic patients and clinical response to neuroleptic treatment, as assessed by the ventricle-brain ratio (VBR) and psychopathology scores, was studied in a sample of 39 patients with schizophrenia or schizoaffective psychosis during a drug-free washout and after 3 1/2 weeks of treatment with either haloperidol or thioridazine. There was a weak, but statistically significant positive relationship between VBR and improvement on BPRS Psychosis factor scores after 3 1/2 weeks of treatment, and a negative correlation between VBR and baseline (washout) scores on the BPRS Anergia factor. Patients with enlarged VBRs, as defined by two criteria, also tended to show a better response to neuroleptics than patients below these criterion values.