Chemopreventive activity of methanol extract of Melastoma malabathricum leaves in DMBA-induced mouse skin carcinogenesis

Background: Melastoma malabathricum L. Smith (family Melastomaceae) is a shrub that has been used by the Malay practitioners of traditional medicine to treat various types of ailments. The present study aimed to determine the chemopreventive activity of methanol extract of M. malabathricum leaves (MEMM) using the standard  7,12-dimethylbenz(á)anthracene (DMBA)/croton oil-induced mouse skincarcinogenesis model.Materials and Methods: In the initiation phase, the mice received a single dose of 100ìl/100 ìg DMBA (group I-V) or 100µl acetone (group VI) topically on the dorsal shaved skin area followed by the promotion phase involving treatment with the respective test solutions (100 ìl of acetone, 10 mg/kg curcumin or MEMM (30, 100 and 300mg/kg)) for 30 min followed by the topical application of tumour promoter (100µl croton oil). Tumors were examined weekly and the experiment lasted for 15 weeks.Results: MEMM and curcumin significantly (p<0.05) reduced the tumour burden, tumour incidence and tumour volume, which were further supported by the histopathological findings.Conclusion: MEMM demonstrated chemoprevention possibly via its  antioxidant and anti-inflammatory activities, and the action of flavonoids like quercitrin.Key words: Melastomaceae; skin cancer; anti-carcinogenic activit

Wandering spleen: a unique cause of acute abdomen

We present the case of a 16-year-old boy presented with 2-week episode of wor­sening lower abdominal pain. Clinically, there was a tender palpable mass on the suprapubic region. Ultrasonography showed an absent spleen at its usual area, instead suprapubic mass suggestive of ectopic spleen was identified. An emer­gency laparotomy revealed a congested spleen in the pelvic cavity. Splenectomy was undertaken as it was non-viable. The patient was discharged uneventfully with triple vaccinations. We describe this unique entity with its literature review. (Folia Morphol 2018; 77, 2: 400–402

Potential of sugar beet vinasse as a feedstock for biocatalyst production within an integrated biorefinery context

BACKGROUND: This work explores the feasibility of vinasse as an inexpensive feedstock for industrial biocatalyst production within the context of an integrated sugar beet biorefinery. As an exemplar, production of CV2025 ω-Transaminase (ω-TAm) in Escherichia coli BL21 was studied. RESULTS: Characterisation of vinasse showed that it comprised mainly of glycerol along with several reducing sugars, sugar alcohols, acetate, polyphenols and protein. Preliminary results showed E. coli BL21 cell growth and CV2025 ω-TAm production were feasible in cultures using 17% to 25% (v/v) vinasse with higher concentrations demonstrating inhibitory effects. The d-galactose present in vinasse facilitated auto-induction of the pQR801 plasmid enabling CV2025 ω-TAm expression without addition of expensive Isopropyl-β-d-thiogalactopyranoside (IPTG). Assessment of different vinasse pre-processing options confirmed simple dilution of the vinasse was sufficient to reduce the concentration of polyphenols to below inhibitory levels. Optimisation experiments, carried out using a controlled, 24-well microbioreactor platform, showed supplementation of diluted vinasse medium with 10 g L^{−1} yeast extract enabled enhancements of 2.8, 2.5, 5.4 and 3-fold in specific growth rate, maximum biomass concentration, CV2025 ω-TAm volumetric and specific activity, respectively. Investigation into the metabolic preferences of E. coli BL21 when grown in vinasse showed a preference for D-mannitol utilisation before simultaneous metabolism of glycerol, d-xylitol, d-dulcitol and acetate. Scale-up of optimised conditions for batch CV2025 ω-TAm production to a 7.5 L stirred tank reactor (STR) was demonstrated based on matched volumetric mass transfer coefficient (kLa). The results showed good comparability with respect to cell growth, substrate consumption and CV2025 ω-TAm production representing over a 700-fold volumetric scale translation. Further enhancements in CV2025 ω-TAm production were possible in the STR when operated at higher k_{L}a values. CONCLUSION: This work describes the promising application of vinasse for production of microbial enzymes and insights into carbon source utilisation in complex feedstocks. Exploitation of vinasse as a fermentation feedstock could be further extended to other processes involving different microorganisms and target enzymes

Gastroprotective activity and mechanisms of action of Bauhinia purpurea Linn (Leguminoseae) leaf methanol extract

Purpose: To determine the gastroprotective activity and mechanisms of protection of the methanol extract of Bauhinia purpurea leaves (MEBP) using ethanol-induced gastric ulcer model.Methods: Male Sprague Dawley rats (n = 6) were administered orally with 10 % DMSO, 100 mg/kg ranitidine or MEBP (50, 250 and 500 mg / kg) daily for 7 consecutive days prior to subjection to the ethanol-induced gastric ulcer assay. The mechanisms of gastroprotection were determined based on: i) antisecretory activity via pylorus ligation assay; ii) the role of nitric oxide (NO) and sulfhydryl group via pre-treatment of MEBP-treated rats with the respective N-nitro-L-arginine methyl ester (L-NAME) or carbenoxolone (CBX) followed by the ethanol-induced assay; and iii) antioxidant activity using superoxide anion radical scavenging assay and, oxygen radical absorbance capacity (ORAC) assay. Ranitidine (100 mg / kg) was used as the reference drug. .Results: MEBP exhibited a significant (p < 0.05) and dose-dependent gastroprotective activity against ethanol-induced gastric ulcer with ulcer formation ranging between 0 and 74 % (indicated by decrease in ulcer area from 21.3 to 5.5 mm2). The macroscopic observation was in line with the microscopic findings and further supported by the histological scores suggesting the antiulcer potential of MEBP. MEBP also significantly (p < 0.05) reduced volume gastric juice, as well as its free and total acidity while increasing its pH. Moreover, this activity was significantly (p < 0.05) modulated in the presence ofsulfhydryl group, but not NO. The extract also exhibited significant (p < 0.05) antioxidant activity.Conclusion: MEBP exerts gastroprotective activity partly via its antisecretory and antioxidant activities, as well as by modulation of sulfhydryl group, but not NO action.Keywords: Bauhinia purpurea, Gastroprotective activity, Gastric ulcer, Sulfhydryl group, Anti-secretory activity, Antioxidan

A Review of CMOS Low Noise Amplifier for UWB System

A number of CMOS low noise amplifier (LNA) design for ultra-wideband (UWB) application had been produced with a various topology and techniques from year 2004 to 2016. The performance of LNA such as frequency bandwidth, noise figure, input and output matching and gain depend with the choice of the topology and technique used. Among the techniques introduced are current reuse, common source, resistive feedback, common gate, Chebyshev filter, distributed amplifier, folded cascade and negative feedback. This paper presents the collection of review about design of low noise amplifier used for UWB application in term of topology circuit. Thus, the problem and limitation of the CMOS LNA for UWB application are reviewed. Furthermore, recent developments of CMOS LNAs are examined and a comparison of the performance criteria of various topologies is presented

Theories of change and evaluation of Malaysian rural internet centers

This early stage of the research generates three different theories of change for three categories of Rural Internet Centers (RICs) in Malaysia. The cyber café model, the community service center model and the entrepreneurial center models emerged through local community needs. The paper describes findings from the early phase of research that was conducted to evaluate the impact of utilization of connectedness and empowerment through rural internet centres (RIC)

Alsolation and characterization of a heavy metalreducing enterobacteriaceae bacterium strain DRY 7 with the ability to assimilate phenol and diesel

Background/Objectives: Molybdenum, phenol and diesel are toxic to organism, and are part of global pollution. Their removal using microorganisms with multiple detoxification ability is being intensely sought as a cleaner and economic approach. Methods/Statistical analysis: A soil suspension was spread plated on a minimal salts media supplemented with molybdenum. Blue colonies, indicating molybdenum reduction was then screened for phenol and diesel degradation capabilities. Findings: A molybdenum-reducing bacterium locally isolated showed the ability to grow on phenol and diesel. The bacterium required pHs of between 5.8 and 6.3 and temperatures of between 30 and 40oC for optimal reduction. Among the carbon sources tested for supporting reduction, glucose was the best. A critical concentration of phosphate at just 5 mM was required, while molybdenum (sodium molybdate) was required between 15 and 25 mM. The absorption spectrum of the Mo-blue produced showed a characteristic maximum peak at 865 nm. The reduction of molybdenum was inhibited by the ions mercury, copper, chromium, lead and silver by 78.9, 78.4, 77.4, 53.5 and 36.8%, respectively. Analysis using phylogenetic analysis identifies the bacterium as Enterobacteriaceae bacterium strain DRY7. Growth on phenol and diesel as carbon sources showed that the optimal concentrations supporting growth was between 300 and 400 mg/L and between 300 and 500 mg/L, respectively. Application/Improvements: The capacity of this bacterium to detoxify a number of toxicants is an important property or bioremediation of soils contaminated with multiple toxicants