Bacterial contaminations of informally marketed raw milk in ghana

Summary BACKGROUND: Milk has an outstanding nutritional quality but is also an excellent medium for bacterial growth and an important source of bacterial infection when consumed without pasteurization. OBJECTIVE: To estimate the bacterial health risk of milk consumption in Accra and Kumasi, the two major cities in Ghana. METHOD: A total of 96 raw milk samples collected in 2002 from the two sites were cultured and the isolated organisms identified by standard bacteriological methods. RESULTS: Overall, the organisms identified and their prevalence rates were Yersinia spp. (19.8%), Klebsiella spp (16.7%), Proteus spp. (7.3%), Enterobacter spp. (6.3%), Escherichia coli (2.1%), and Staphylococcus spp (14.6%), Bacillus spp. (11.5%) and Mycobacterium spp. (1%). Most of the organisms identified were enterobacteria indicating probable faecal contamination of the milk as a result of poor hygiene. Most of the bacteria identified in the milk sampled are potential food-borne pathogens, and though some of them occurred in few samples, the practice of pooling milk from different sources by traders, and the absence of pasteurization generally observed among them could increase the risk posed by such organisms. CONCLUSION: The study has shown that informally marketed raw milk in the two cities could be an important source of infection with a wide range of organisms, particularly enterobacteria. There is the need for instituting effective control measures including improved hygienic handling of milk and its pasteurization to protect public health.     

Stimulation of angiotensin AT2 receptors by the non-peptide agonist,Compound 21, evokes vasodepressor effects in conscious spontaneously hypertensive rats

Background and purpose:

Angiotensin type 2 receptor (AT₂ receptor) stimulation evokes vasodilator effects in vitro and in vivo that oppose the vasoconstrictor effects of angiotensin type 1 receptors (AT₁ receptors). Recently, a novel non-peptide AT₂ receptor agonist, Compound 21, was described, which exhibited high AT₂ receptor selectivity.

Experimental approach:

Functional cardiovascular effects of the drug candidate Compound 21 were assessed, using mouse isolated aorta and rat mesenteric arteries in vitro and in conscious spontaneously hypertensive rats (SHR).

Key results:

Compound 21 evoked dose-dependent vasorelaxations in aortic and mesenteric vessels, abolished by the AT₂ receptor antagonist, PD123319. In vivo, Compound 21 administered alone, at doses ranging from 50 to 1000 ng·kg⁻¹·min⁻¹ over 4 h did not decrease blood pressure in conscious normotensive Wistar-Kyoto rats or SHR. However, when given in combination with the AT₁ receptor antagonist, candesartan, Compound 21 (300 ng·kg⁻¹·min⁻¹) lowered blood pressure in SHR only. Further analysis in separate groups of conscious SHR revealed that, at a sixfold lower dose, Compound 21 (50 ng·kg⁻¹·min⁻¹) still evoked a significant depressor response in adult SHR (∼30 mmHg) when combined with different doses of candesartan (0.01 or 0.1 mg·kg⁻¹). Moreover, the Compound 21-evoked depressor effect was abolished when co-infused (50 µg·kg⁻¹·min⁻¹ for 2 h) with the AT₂ receptor antagonist PD123319.

Conclusion and implications:

Collectively, our results indicate that acute administration of Compound 21 evoked blood pressure reductions via AT₂ receptor stimulation. Thus Compound 21 can be considered an excellent drug candidate for further study of AT₂ receptor function in cardiovascular disease.     

The effects of common genetic variants in oncogenes on ovarian cancer survival

PURPOSE: The 5-year survival rate for invasive epithelial ovarian cancer is <35%. It has been suggested that common, germline genetic variation may influence survival after cancer diagnoses, which might enable the prediction of response to treatment and survival in the clinical setting. The aim of this study was to evaluate associations between common germline genetic variants in the oncogenes BRAF, ERBB2, KRAS, NMI, and PIK3CA, and survival after a diagnosis of epithelial ovarian cancer. EXPERIMENTAL DESIGN: We evaluated the association between 34 tagging single nucleotide polymorphisms and survival in 1,480 cases of invasive epithelial ovarian cancer cases from three different studies. Cox regression analysis, stratified by study, was used to estimate per rare allele hazard ratios (HR). RESULTS: The minor allele rs6944385 in BRAF was significantly associated with poor survival [HR, 1.19; 95% confidence intervals (95% CI), 1.02-1.39; P = 0.024]. The association remained after adjusting for prognostic factors (adjusted HR, 1.20; 95 CI, 1.03-1.40; P = 0.018). A haplotype of BRAF was also associated with poor survival (HR, 1.24; 95% CI, 1.02-1.51; P = 0.029) and was more significant after adjustment (HR, 1.44; 95% CI, 1.15-1.81; P = 0.001). We also found evidence of an association between a KRAS haplotype and poor survival in serous subtype (HR, 1.69; 95% CI, 1.21-2.38; P = 0.002), but this was no longer significant after adjustment. Finally, when analyses were restricted to the serous histologic subtype, the rare allele rs10842513 in KRAS, was associated with poor survival (HR, 1.40; 95% CI, 1.10-1.78; P = 0.007). CONCLUSION: Common genetic variants in the BRAF and KRAS oncogenes may be important in the prediction of survival in patients with invasive epithelial ovarian cancer.     

Aquatic invertebrates as unlikely vectors of Buruli ulcer disease

Buruli ulcer is a necrotizing skin disease caused by Mycobacterium ulcerans and associated with exposure to aquatic habitats. To assess possible transmission of M. ulcerans by aquatic biting insects, we conducted a field examination of biting water bugs (Hemiptera: Naucoridae, Belostomatidae, Nepidae) in 15 disease-endemic and 12 non-disease-endemic areas of Ghana, Africa. From collections of 22,832 invertebrates, we compared composition, abundance, and associated M. ulcerans positivity among sites. Biting hemipterans were rare and represented a small percentage (usually <2%) of invertebrate communities. No significant differences were found in hemipteran abundance or pathogen positivity between disease-endemic and non-disease-endemic sites, and between abundance of biting hemipterans and M. ulcerans positivity. Therefore, although infection through insect bites is possible, little field evidence supports the assumption that biting hemipterans are primary vectors of M. ulcerans.     

Haptoglobin 2-2 phenotype is a risk factor for type 2 diabetes in Ghana

We have investigated the role of haptoglobin gene polymorphisms in 129 type 2 diabetic patients and 87 non-diabetic subjects, classified by the ADA criteria, in Ghana. The diabetic subjects were recruited consecutively from the National Diabetic Management and Research Center of the University of Ghana Medical School, Korle-Bu, Accra, Ghana and were categorized by their haptoglobin phenotypes. The haptoglobin 2 allele was determined to be a risk factor for type 2 diabetes in Ghana (OR = 6.1, 95% CI = 1.8-21.2; P = .0.001) while the Hp1 allele appeared protective (OR = 0.56, 95% CI = 0.31-1.0; P = .06). The deleterious role of the Hp2 allele was further evidenced by the reduced risk associated with Hp2-1M mutant heterozygotes, who produce less Hp2 protein than the normal Hp2-1 heterozygote. (OR = 0.52, 95% CI = 0.27-1.0; P = 0.06). The subjects with the homozygous Hp2 allele were also hypertensive and overweight. There was no difference (p > 0.05) in the levels of triglycerides, total cholesterol, LDL and HDL between diabetic subjects with different haptoglobin phenotypes.We conclude that hypertensive and overweight individuals with the Hp2-2 phenotype in Ghana are at a high risk of developing type 2 diabetes and may require a more aggressive management.     

Application of the network scale-up method to estimate the sizes of key populations for HIV in Singapore using online surveys

Introduction

Singapore lacks robust data on the sizes of the key populations that are most at risk for HIV. Using the network scale-up method for hidden or hard-to-reach populations, we estimate the sizes of five key populations—male clients of female sex workers (MCFSW), men who have sex with men (MSM), female sex workers (FSW), people who inject drugs (PWID) and transgender people—and profile the ages and ethnicities of respondents with the high-risk contacts they report knowing.

Methods

We conducted a cross-sectional online survey between March and May 2019 (n = 2802) using a network scale-up instrument previously developed for Singapore. Participants were recruited using an existing panel and online advertising, and the sample reweighted by age, sex, ethnicity and education attained to represent the general adult population. We built a Bayesian hierarchical model to estimate the sizes of the five key populations for HIV in Singapore.

Results

After adjustment, the sizes of the at-risk populations are estimated to be: 76,800 (95% credible interval [CI]: 64,200–91,800) MCFSW; 139,000 (95% CI: 120,000–160,000) MSM; 8030 (95% CI: 3980–16,200) FSW; 3470 (95% CI: 1540–7830) PWID and 18,000 (95% CI: 14,000–23,200) transgender people. Generally, men reported knowing more people in all the high-risk groups; older people reported knowing more MCFSW, FSW and transgender people; and younger people reported knowing more MSM. There was a bimodal effect of age on those who reported knowing more PWIDs: people in their 20s and 60s reported more contacts.

Conclusions

This study demonstrates that a size estimation study of hidden populations is quickly and efficiently scalable through using online surveys in a socially conservative society, like Singapore, where key populations are stigmatized or criminalized. The approach may be suitable in other countries where stigma is prevalent and where barriers to surveillance and data collection are numerous.