Production and Anticancer Activity of an L-Asparaginase from Bacillus licheniformis Isolated from the Red Sea, Saudi Arabia.

Microbial L-asparaginase (ASNase) is an important anticancer agent that is used extensively worldwide. In this study, 40 bacterial isolates were obtained from the Red Sea of Saudi Arabia and screened for ASNase production using a qualitative rapid plate assay, 28 of which were producing large L-asparagine hydrolysis zones. The ASNase production of the immobilized bacterial cells was more favorable than that of freely suspended cells. A promising isolate, KKU-KH14, was identified by 16S rRNA gene sequencing as Bacillus licheniformis. Maximal ASNase production was achieved using an incubation period of 72 h, with an optimum of pH 6.5, an incubation temperature of 37 °C, an agitation rate 250 rpm, and with glucose and (NH4)2SO4 used as the carbon and nitrogen sources, respectively. The glutaminase activity was not detected in the ASNase preparations. The purified ASNase showed a final specific activity of 36.08 U/mg, and the molecular weight was found to be 37 kDa by SDS-PAGE analysis. The maximum activity and stability of the purified enzyme occurred at pH values of 7.5 and 8.5, respectively, with maximum activity at 37 °C and complete thermal stability at 70 °C for 1 h. The Km and Vmax values of the purified enzyme were 0.049995 M and of 45.45 µmol/ml/min, respectively. The anticancer activity of the purified ASNase showed significant toxic activity toward HepG-2 cells (IC50 11.66 µg/mL), which was greater than that observed against MCF-7 (IC50 14.55 µg/mL) and HCT-116 cells (IC50 17.02 µg/mL). The results demonstrated that the Red Sea is a promising biological reservoir, as shown by the isolation of B. licheniformis, which produces a glutaminase free ASNase and may be a potential candidate for further pharmaceutical use as an anticancer drug.

Identification of Acinetobacter clinical isolates by polymerase chain reaction analysis of 16S-23S ribosomal ribonucleic acid internal transcribed spacer.

BACKGROUND: The genus Acinetobacter is a diverse group of Gram-negative bacteria involve at least 33 species using the molecular methods. Although the genus Acinetobacter comprises a number of definite bacterial species, some of these species are of clinical importance. Therefore, it is of vital importance to use a method which is able to reliably and efficiently differentiate the numerous Acinetobacter species. OBJECTIVES: This study aims to identify Acinetobacter of clinical isolates from Assir region to the species level by 16S-23S intergenic spacers internal transcribed spacer (ITS) of ribosomal ribonucleic acid (rRNA). MATERIALS AND METHODS: Deoxyribonucleic acid extraction, polymerase chain reaction amplification of 16S-23S intergenic spacer sequences (ITS) was performed using the bacterium-specific universal primers. RESULTS: Based on the 16S-23S intergenic spacers (ITS) of rRNA sequences, all isolates tested were identified as Acinetobacter baumannii. The isolates shared a common ancestral lineage with the prototypes A. baumannii U60279 and U60280 with 99% sequence similarities. CONCLUSION: These findings confirmed 16S-23S rRNA ITS for the identification of A. baumannii of different genotypes among patients.

Cardiocytolytic antimyolemmal antibodies in dilated cardiomyopathy following presentation: observations in 7 patients.

The prevalence of lytic activity of circulating antimyolemmal antibodies in dilated cardiomyopathy of recent onset is unclear. To obtain preliminary data we studied 7 consecutive patients with dilated cardiomyopathy (age 44 +/- 14 years) and symptoms for fewer than 6 months. The presence of antimyolemmal antibodies was determined in vitro using intact rat and human cardiocytes and indirect immunofluorescence. Serum cytolytic index for antimyolemmal antibodies was measured by microcytotoxicity assay and the data were compared with that from 70 controls (normal range 0.92 +/- 0.07, effective cytolysis < 0.75). Autoantibody screening was uniformly negative and only 1 patient had positive viral serology. Light microscopy of cardiac biopsies revealed non-specific histology in 2, focal myocarditis in 1 and healing or healed myocarditis in 4. Significant binding of IgG, IgM or polyvalent antibodies to antimyolemmal antibodies bound to rat or human cardiocytes was present in every patient and 5 of them were positive with all 3 markers. Cytolytic index for the group ranged from 0.47 to 0.60 indicating effective lysis in all patients (P < 0.01 versus controls). Cardiocytolytic antimyolemmal antibodies are commonly present in dilated cardiomyopathy following presentation. Their detection might reflect ongoing disease activity and help identify patients likely to benefit from immunomodulative therapy.

Aspirin to prevent growth of vegetations and cerebral emboli in infective endocarditis.

The incidence of stroke on cranial computed tomography (CT) and change in echocardiographic vegetation area was prospectively compared in a preliminary observational study involving nine patients with infective endocarditis randomized to either low-dose aspirin (75 mg d-1, Group I, n = 4) or no aspirin (Group II, n = 5). Two symptomatic cerebral infarcts and one myocardial infarct occurred in the controls, compared to no events in patients on aspirin during a total observation period of 343 d (range 28-49 d). The mean vegetation area decreased in the aspirin group (mean change = -0.24 cm2), compared to an increase in controls (mean change = +0.35 cm2). The platelet half-life (normal range 5-6 d), which was measured using Indium-111 radiolabelling, tended to be lower in Group II (4.6 +/- 0.2 vs. 3.9 +/- 0.5 d). No side-effects or complications attributable to aspirin were observed. A possible role for adjunctive aspirin therapy in the prevention of embolic complications in infective endocarditis is suggested, and warrants further study.

Hemostatic studies in patients with infective endocarditis: a report on nine consecutive cases with evidence of coagulopathy.

Local and generalized changes in coagulation may be important in the genesis of vegetations and embolism in infective endocarditis. To characterize such alterations, serial hematological investigations were performed on nine consecutive patients who satisfied the inclusion criteria. Platelet survival was measured by Indium111 labeling. Acute and convalescent samples were analyzed for fibrinogen, factor VIIIc, antithrombin III (AT III), fibrin/fibrinogen degradation products (FDPs), and platelet aggregation. The results suggest that in the active stage of the disease: (1) hypercoagulability may be caused by a rise in acute phase reactants, (2) an acceleration of coagulation and fibrinolysis may supervene, and (3) in some cases there is a reduction in platelet aggregation, possibly as a result of continued circulation of previously activated "exhausted" platelets.

Diabetes mellitus in Kuwait. Incidence in the first 29 years of life.

The annual incidence of diabetes mellitus among Kuwaiti subjects 0-29 years of age during 1980-1981 was found to be 22.09 per 100,000. There was a very low incidence in the 0-14 and 0-19 year age groups (3.96 per 100,000 and 5.61 per 100,000, respectively). The age distribution at onset shows an increase in incidence with age without exhibiting any remarkable peaks. The total number of female diabetic patients exceeded the number of males by 32%, the male/female sex ratio being found to be 0.68, which is significantly less than that of the same age group in the general population.