Multimeric composition of endothelial cell-derived von Willebrand factor

The multimeric composition of human endothelial cell (EC)-derived von Willebrand factor (vWF) was studied using SDS-agarose gel electrophoresis and autoradiography. Two multimers were found in lysates prepared from confluent cultures of human umbilical vein endothelial cells. The smaller multimer had a molecular weight (mol wt) of approximately 950 Kd, while the second was larger than those seen in plasma. When electrophoresis was performed using the discontinuous buffer system of Ruggeri and Zimmerman, the small multimer consisted of a single band migrating with the slowest-moving component of the corresponding plasma triplet. The large EC-vWF multimer was detected in culture media conditioned with EC monolayers for ten minutes. It remained the only multimer in media conditioned for up to three days. Calcium ionophore A23187 increased the amount of the large vWF multimer released into the culture media, but did not change its multimeric composition. The small multimer was never detected in the EC- conditioned media. These findings suggest that (1) a large, fully polymerized multimer of vWF is released from the ECs, while the small multimer probably represents a major intermediate component in the process of multimerization, and (2) plasma vWF multimers are probably generated from the large endothelial vWF after it is released into the circulation.     

Evaluation of Aerosol and Water Contamination and Control of Cross Infection in Dental Clinics

Background

The oral cavity is an unique environment which provides an ideal medium for bacterial growth. As a result of repeated exposure to the microorganisms present in blood and saliva, the dental health professionals and the patients are at a higher risk for developing many infectious diseases. A pilot study was carried out in the Dept of Dental Surgery, Armed Forces Medical College to assess the risk of cross infection in dental clinics.

Methods

Samples were collected from different dental surgeries of the Dept of Dental Surgery, Armed Forces Medical College and sent for microbiological culture and identification to the Dept of Microbiology, Armed Forces Medical College. The sampling was carried out in two stages, before and after implementing a set protocol.

Result

All dental unit waterlines were coated with a well established biofilm made up of filamentous and bacillus-like microorganisms in first stage of study. There was marked reduction in the number of colonies from the samples collected during second stage. Same findings were observed in the samples of aerosol produced by ultrasonic scalers.

Conclusion

The present study concluded that the new set protocol followed is significantly effective in reducing the microbial load in the water tubing, container and aerosol production. It is an effective measure for reducing the chances of cross infection in the dental surgeryKey Words: Aerosol, Biofilm, Cross infection, Colony forming units     

<Emphasis Type="Italic">In vitro</Emphasis> antibacterial activity and acute toxicity studies of aqueous-methanol extract of <Emphasis Type="Italic">Sida rhombifolia</Emphasis> Linn. (Malvaceae)

Background  

Many bacteria among the Enterobacteria family are involved in infectious diseases and diarrhoea. Most of these bacteria become resistant to the most commonly used synthetic drugs in Cameroon. Natural substances seem to be an alternative to this problem. Thus the aim of this research was to investigate the in vitro antibacterial activity of the methanol and aqueous-methanol extracts of Sida rhombifolia Linn (Malvaceae) against seven pathogenic bacteria involved in diarrhoea. Acute toxicity of the most active extract was determined and major bioactive components were screened.     

Effect of ionizing radiation on functional activity of macrophagesĭ

It was shown that in vitro irradiation (8 Gy) of murine peritoneal macrophages suppressed their spontaneous cytotoxity and induced growth-stimulating activity. Exposure to 4 Gy induced mRNA proximal factors--TGF-beta and TNF-alpha and boosted growth-stimulating activity. These effects should be considered when evaluating efficacy of radiotherapy for tumors.     

Comparative evaluation of bioglass with calcium sulphate β-hemihydrate for the treatment of intraosseous defects—a clinico-radiological study

Background

The aim of the present clinical and radiological study was to compare bioglass and calcium sulphate β-hemihydrate in the treatment of intraosseous defect in chronic periodontitis.

Method

A total of 50 subjects with bilaterally symmetrical periodontal osseous defects with probing pocket depth = 5 mm and intraosseous defects ≥ 3 mm as seen on the radiographs were undertaken for the study. In one site (group A) bioactive glass was placed in defect and in contralateral site (group B) calcium sulphate β-hemihydrate was used in the defect site.

Results

Clinical improvement was noted in all patients at the end of study. Both the groups showed reduction in probing pocket depth, increase in clinical attachment level, and reduction in osseous defect. Both materials were effective in achieving osseous gain.

Conclusion

The osseous gain in group A subjects was 58.93%, whereas in group B subjects it was 48.56%. Calcium sulphate β-hemihydrates showed promising results and were cost effective.     

Is there any relationship between serum and urine neopterin and serum interferon‐γ levels in the activity of Behcet's disease?

Background  Behcet's disease (BD) is a chronic, inflammatory, multisystem vasculitic disorder. There is no reliable laboratory marker that indicates disease activity. Neopterin is an immunological marker of cellular immune activation, which is secreted by monocytes/macrophages as a result of interferon-gamma (IFN-γ) secretion by activated T lymphocytes.
Objective  We aimed to investigate serum and urine neopterin levels in BD patients.
Methods  Forty-five patients who were diagnosed according to the criteria of the International Study Group for BD and 45 age- and sex-matched healthy controls were enrolled in the study. Disease activity was considered by clinical findings. Serum and urine neopterin levels and serum IFN-γ levels were measured.
Results  The mean values of serum and urine neopterin levels were 12.68 ± 4.87 nmol/L and 167.53 ± 148.73 µmol/mol creatinine, respectively, in BD patients ( P =  0.000 and P  = 0.008, respectively), which were statistically significantly different from the control group. However, there was no significant statistical difference between serum and urine neopterin levels of the clinically active and inactive patients. It was also found that the mean value of serum IFN-γ levels was higher in healthy controls than in BD patients ( P =  0.000).
Conclusions  We conclude that serum and urinary neopterin measurement can not be used as a reliable laboratory marker as the BD patients' serum and urinary neopterin levels do not increase in the active stage even though these levels increase when compared to healthy controls.     

Peripheral blood stem cells used to augment autologous bone marrow transplantation

Peripheral blood stem cells (PBSC) were used to augment autologous bone marrow transplantation (ABMT), aiming to hasten engraftment after high dose treatment in a group of heavily pretreated patients. PBSC were obtained by leukapheresis during the rebound after standard chemotherapy. In 11 patients aged 7-17 years, high dose chemotherapy consisted of busulphan 16 mg/kg orally with melphalan 160 mg/m2 intravenously for seven patients, and melphalan 200 mg/m2 intravenously alone for four. The median number of granulocyte-macrophage colony forming units in the reinfused PBSC was 3.42 x 10(4)/kg (3.03-18.01) and bone marrow 12.4 x 10(4)/kg (4.16-28.6). Neutrophil recovery to > or = 0.5 x 10(9)/l and platelet transfusion independence occurred at a median of 14 days (11-18) and 22 days (9-84) respectively. In five patients the early engraftment was transient with neutrophils again dropping below 0.5 x 10(9)/l then slowly recovering. There was one toxic death due to sepsis. PBSC harvesting in these children was undertaken without interrupting routine chemotherapy and without the use of bone marrow growth factors. In some patients PBSC failed to influence engraftment and the use of combined chemotherapy and growth factor priming for PBSC collection may give improved results.