Genetic typing of equine arteritis virus isolates from Argentina

We report the nucleotide sequence and genetic diversity of four Equine Arteritis Virus (EAV) ORF 5 and 6 from Argentina isolates, obtained from asymptomatic virus-shedding stallions. Nucleic acid recovered from the isolates were amplified by RT-PCR and sequenced. Nucleotide and deduced amino acid sequences from the Argentine isolates were compared with 17 sequences available from the GenBank. Phylogenetic analysis revealed that the Argentine isolates grouped together in a definite cluster near European strains. Despite the greater genetic variability among ORF 5 from different isolates and strains of EAV, phylogenetic trees based on ORF 5 and 6 are similar. Both trees showed that virus sequences from America and Europe segregate into distinct clades based on sequence analysis of either ORF 5 or 6. This study constitutes the first characterization of Argentine EAV isolates. M. G. Echeverría, S. Díaz, E. Nosetto Members of CONICET (Scientific Research Council)     

Living conditions of children at risk for noma: Nigerian experience

The study reported in this paper was carried out in the Northwestern and Southwestern regions of Nigeria, between October 1996 and April 1998. The study examined the possible contributory role of living conditions in the development of acute necrotizing gingivitis (ANG) or noma from oral lesions. Questionnaire data obtained from 42 fresh noma cases seen in the Northwest and four fresh cases seen in the Southwest were examined. In addition 46 cases of advanced ANG from the Southwest were included. The main focus was to compare some of the environmental living conditions of cases with advanced ANG and those with noma in these regions. All the noma and ANG cases were seen in children aged 2-12 years. The level of good oral hygiene practices and general environmental living conditions were significantly higher in the Southwest than in the Northwest. Data also showed that living in close proximity with livestock was significantly higher in the Northwest than in the Southwest (P < 0.05). The environmental living conditions of children in the Northwest were further compounded by poor sanitary faecal disposal practices as well as minimal access to potable water. The overall data indicated that living in substandard accommodations, exposure to debilitating childhood diseases, living in close proximity to livestock, poor oral hygiene, limited access to potable water and poor sanitary disposal of human and animal faecal waste could have put the children in the Northwest at higher risk for noma than the children in the Southwest. These could have been responsible for the higher prevalence of noma in the Northwest than in the Southwest.     

Anaemia in pregnancy: associations with parity,abortions and child spacing in primary healthcare clinic attendees in Trinidad and Tobago

Objective

To determine the prevalence of anaemia in antenatal clinic attendees; to investigate the effects of parity, age, gravidity, previous abortions, child spacing and other factors on the prevalence of anaemia in pregnancy.

Methods

This was a retrospective and cross-sectional study. Antenatal records of 2287 pregnant women attending 40 public healthcare centres from January 2000 to December 2005 in Trinidad and Tobago were used. Data pertaining to the investigated variables were recorded. The national prevalence of anaemia was calculated and chi-square tests, odds ratios and logistic regression were used to assess the relationship between anaemia and each variable.

Results

The prevalence of anaemia was 15.3% (95% CI 13.4%, 16.6%). No significant difference in the prevalence of anaemia was found among the different clinics or counties. At the first haemoglobin reading, age was inversely related to the presence of anaemia, whereas gestational age at first visit was directly related. At the final haemoglobin reading, parity, gravidity, and previous spontaneous abortions were directly related to the prevalence of anaemia, while the number of visits was inversely related. Age was inversely associated to the severity of anaemia while gravidity was directly related.

Conclusion

The prevalence of anaemia decreased by 18.7% from 1967. Despite this positive indication, women under 24 years and those commencing antenatal care after the first trimester are still at a higher risk for developing anaemia. Early commencement of antenatal care and close monitoring of the risk groups identified should be strongly advocated.     

Regional differences in the vasorelaxant effects of nicorandil and amlodipine on isolated porcine coronary arteries

Summary— The vasorelaxant effects of nicorandil, a K⁺-channel opener, and amlodipine, a dihydropyridine-type Ca²⁺-channel blocker, were investigated on partially and maximally K⁺-depolarized ring preparations from the porcine left anterior descending coronary artery. By comparing vascular responses in the proximal and distal parts of the epicardial segment, the scope of the study was to evaluate regional differences in the action of nicorandil and amlodipine. Nicorandil (10 ⁷- 10^-4 M) shifted the K⁺ concentration-response curves to the right and depressed the maximal contractile responses in a concentration-dependent manner, consistent with K⁺-channel opening and secondary non-K⁺-channel opening mechanisms of action. Nicorandil had a significantly more potent relaxant effect in the proximal compared to the distal arterial rings contracted with 85 mM K⁺. Pretreatment with methylene blue (10^-5 M) did not significantly influence the regional difference in the action of nicorandil. Amlodipine (10⁹- 10^-6 M) had a significantly more potent and effective inhibitory and relaxant effect than nicorandil under the same conditions. In contrast to nicorandil, the effect of amlodipine was more prominent in the distal compared to the proximal vessel rings. The cumulative addition of extracellular Ca²⁺ exhibited a more potent contractile response in the distal rather than in the proximal rings. Nicorandil totally and amlodipine partly eliminated the contractile responses to the lowest concentration of Ca²⁺. The inhibitory effect of amlodipine on the contractile responses to higher Ca²⁺ concentrations was more pronounced than that of nicorandil. The results show that there are regional differences in the responsiveness of porcine coronary arteries to Ca²⁺, nicorandil and amlodipine. Our findings indicate that the regional difference in nicorandil-induced vasodilation was caused neither by the K⁺-channel opening nor by the nitrate-like mechanism of action, but could be due to a direct Ca²⁺-influx blocking effect of the drug.     

The Novel Antihyperglycaemic Action of Hunteria Umbellata Seed Fractions Mediated Via Intestinal Glucose Uptake Inhibition

The present study evaluated the antihyperglycaemic effect and mechanism of action of fractions of the aqueous seed extract of Hunteria umbellata (K. Schum.) Hallier f. (HU) in normal and alloxan-induced hyperglycaemic rats. HU was partitioned in chloroform, acetyl acetate and butan-1-ol to give chloroform fraction (HU_c), ethyl acetate fraction (HU_e), butanol fraction (HU_b) and the “residue” (HU_m), respectively. 200 mg/kg of each of these fraction dissolved in 5% Tween 20 in distilled water was investigated for its acute oral hypoglycaemic effects in normal rats over 6 hours while its repeated dose antihyperglycaemic effect was evaluated in alloxan-induced hyperglycaemic rats over 5 days. In addition, 50 mg/kg of the crude alkaloid fraction (HU_Af) extracted from HU was evaluated for its possible antihyperglycaemic activity in alloxaninduced hyperglycaemic rats using oral glucose tolerance test (OGTT) over 6 hours. Using the solvent system, distilled water-butanol-ammonium hydroxide (2:15:1, v/v/v), HU_b was chromatographed and stained with Dragendorff''s reagent for confirmatory qualitative analysis for alkaloids. Results showed that oral pre-treatment with 200 mg/kg of HU_e, HU_b and HU_m resulted in a significant (p<0.05, p<0.001) time dependent hypoglycaemic effect, with the butan-1-ol fraction HU causing the most significant (p<0.001) hypoglycaemic effect. In the alloxan-induced hyperglycaemic rats, repeated oral treatment with 200 mg/kg of same HU fractions for 5 days resulted in significant (p<0.05) decreases in the fasting blood glucose concentrations with the most significant (p<0.01) antihyperglycaemic effect also recorded for HU_b. Similarly, oral pretreatment with 50 mg/kg of HU_Af significantly (p<0.05, p<0.01 and p<0.001) attenuated an increase in the post-absorptive glucose concentration at 1^st – 6^th h in the alloxan-induced hyperglycaemic OGTT model. In addition, alkaloid was present in most of the separated spots on the TLC plate. In conclusion, results of this study showed that HU contains a relative high amount of alkaloids which could have accounted for the antihyperglycaemic action of HU that was mediated via intestinal glucose uptake inhibition.     

In vitro and in vivo MMP gene expression localisation by In Situ -RT-PCR in cell culture and paraffin embedded human breast cancer cell line xenografts

Background  

Members of the matrix metalloproteinase (MMP) family of proteases are required for the degradation of the basement membrane and extracellular matrix in both normal and pathological conditions. In vitro, MT1-MMP (MMP-14, membrane type-1-MMP) expression is higher in more invasive human breast cancer (HBC) cell lines, whilst in vivo its expression has been associated with the stroma surrounding breast tumours. MMP-1 (interstitial collagenase) has been associated with MDA-MB-231 invasion in vitro, while MMP-3 (stromelysin-1) has been localised around invasive cells of breast tumours in vivo. As MMPs are not stored intracellularly, the ability to localise their expression to their cells of origin is difficult.