Electrically heated cylindrical microelectrodes. The reduction of dissolved oxygen on Pt

A platinum microelectrode (25 μm diameter cylinder) heated by alternating current was used to study the reduction of oxygen in neutral phosphate buffer solution using cyclic voltammetry. Interference of the a.c. voltage on the electrode process was completely avoided when high frequency a.c. (100 kHz) was used. The electrode temperature was determined indirectly from the changes in open circuit potentials in a hexacyanoferrate(II)/(III) system. The influence of electrode orientation on the contribution of convection to mass transfer was shown by considering horizontally and vertically positioned electrodes. A linear relationship between the reduction currents and the oxygen concentrations was obtained. In all cases the oxygen reduction signals were improved upon heating.     

An electrophysiological analysis of caudally-projecting neurones from the hypothalamic paraventricular nucleus in the rat

Using anaesthetized rats, experiments were performed to test whether neurones located in the hypothalamic paraventricular nuclei and sending axons caudally, could be identified electrophysiologically. Neurones projecting caudally were localized by antidromic invasion following electrical stimulation within the region of the dorsal motor nucleus of the vagus, the nucleus of the tractus solitarius and the hypoglossal nucleus. Stimulation of more ventral regions in the medulla oblongata was not effective. Caudally-projecting neurones were dispersed throughout the paraventricular nuclei and were often found close to magnocellular neurones antidromically invaded by stimulation of the pituitary stalk. About one-third of the caudally-projecting neurones were synaptically activated by pituitary stalk stimulation, but only at currents sufficient to antidromically invade the magnocellular neurones. This suggests a synaptic interaction between magnocellular and some caudally-projecting paraventricular neurones. The possible physiological significance of these findings is discussed.     

Wound infection in Tikur Anbessa hospital, surgical department

A prospective study of surgical wound infection has been conducted on 1754 surgical patients operated from January 1, 1999 to Dec 31, 1999 in Tikur Anbessa hospital. Demographic data and information on potential risk factors and the occurrence of wound infection in the first 30 days post operatively were collected using pretested data collection form. Among the patients 1162 (66.2%) were males and 592 (33.8%) were females. The age ranged from one day to 95 years with a mean of 30 (+/- 19) years. Seven hundred twenty eight (41.5%) wounds were classified as clean, 674 (38.4%) as clean-contaminated, 241 (13.7%) as contaminated and 111 (6.3%) as dirty and infected wounds. The overall wound infection rate was 14.8%. The infection rate for clean, clean-contaminated, contaminated and dirty and infected wounds were 8.0%, 14.8%, 22.0% and 44.2% respectively. The overall wound infection rates vary between 5.4% and 27.9% among consultant surgeons and it was 17.3% for residents. After adjusting for variation in patients condition and wound class, the infection rate of two surgeons was significantly higher, with odds ratio (OR) of 2.3 and 2.9. Shaving in the ward and use of drains were associated with a statistically significantly higher infection rate after adjusting for all factors considered in the study, with OR of 1.9 & 2.3 respectively. Preoperative antibiotics were found to be highly protective after multiple stepwise regressions with OR of 0.33. Post operative hospital stay and mortality were significantly higher in patients who had wound infection after adjusting for potentially confounding variables. It is concluded that the infection rate are much higher than the acceptable standard and this underscores the need for establishing hospital infection control system. Minimizing the use of drains, avoiding preoperative shaving, judicious use of preoperative antibiotics and meticulous surgical technique should be part of the immediate strategy to reduce wound infection rate.     

Phytochemical screening and pharmacological evaluations for the antifertility effect of the methanolic root extract of Rumex steudelii

The practice of traditional medicine for the control of fertility in most parts of Ethiopia is based on the uses of plant medicines for many years. The fact that herbal medicines have been employed for such a long time does not guarantee their efficacy and safety. The aim of the present study was, therefore, to carry out phytochemical screening, efficacy and safety studies on one of the traditionally used antifertility plants: Rumex steudelii. The secondary metabolites of the root of this plant were determined. The methanolic extract of the roots of this plant were investigated for their antifertility activity in female rats and oral LD50 was determined in mice. The identification of the secondary metabolites showed that the roots of the plant contained phytosterols and polyphenols. It was found that the extract reduced significantly (p<0.01) the number of litters. It also produced antifertility effect in a dose dependent manner and the contraceptive effect was manifested for a definite period of time. Furthermore, the extract prolonged significantly the estrus cycle (p<0.05) and the diestrous phase (p<0.01) of the rats. The wet weights of the ovaries and uterus were shown to be reduced significantly (p<0.01) and (p<0.05), respectively. The oral LD50 of the extract was found to be 5 g/kg in mice. All these observations suggest that the extract has antifertility effect and is safe at the effective antifertility doses employed in this study.     

Risk factors for multidrug resistant tuberculosis patients in Amhara National Regional State

Background

Multidrug resistant tuberculosis(MDR-TB) is becoming a major threat to tuberculosis control programs in Ethiopia.

Objectives

To determine risk factors of MDR-TB patients in Amhara National Regional State, Ethiopia.

Methods

Case-control study was conducted from May 2013 to January 2014. Resistance to rifampicin and isoniazid were done molecularly using line probe assay. TB patients infected with MDR-M.tuberculosis and non MDR-M.tuberculosis strain were considered as cases and controls, respectively. Data was collected using structured questionnaire with face to face interview. Patients'' clinical record review was also done.Multivariate analysis was computed to determine the risk factors of MDR-TB.

Results

A total of 153 MDR-TB and equal number of non MDR-TB patients'' participated in the study. Patients who had TB treatment failure (AOR=13.5,CI=2.69–70), cavitations on chest x-ray (AOR=1.9,CI=1.1–3.38) and contact with MDR-TB patients (AOR=1.4,CI=0.19–0.39) were more likely to be MDR-TB patients. Low monthly income (AOR=1.1,CI=0.34–0.47),alcohol consumption (AOR=1.5,CI=0.2–0.98) and young age (AOR=2.9,CI=1.07–7.68) were the other risk factors of MDR-TB.

Conclusions

TB treatment failure, cavitation on chest X-ray, contact with MDR-TB patients and low socioeconomic status were important risk factors for development of MDR-TB. Therefore, strict adherence to directly observed therapy, appropriate management of TB patients and advice on the value of nutrients are helpful to control the spreading of MDR-TB.     

Association of ABO blood group and Plasmodium falciparum malaria in Dore Bafeno Area,Southern Ethiopia

Objective

To assess the distribution of ABO blood group and their relationship with Plasmodium falciparum (P. falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center, Southern Ethiopia.

Methods

A total of 269 febrile outpatients who visited Dore Bafeno Health Center, Southern Ethiopia, were examined for malaria and also tested for ABO blood groups in January 2010. The blood specimens were collected by finger pricking, stained with Geimsa, and examined microscopically. Positive cases of the parasitemia were counted. CareStart™ Malaria Pf/Pv Combo was also used to test the blood specimens for malaria. ABO blood groups were determined by agglutination test using ERYCLONE^® antisera. Data on socio-demographic characteristics and treatment status of the participants were also collected. Chi-square and ANOVA tests were used to assess the difference between frequencies and means, respectively.

Results

Out of a total of 269 participants, 178 (66.2%) febrile patients were found to be infected with Plasmodium parasites, among which 146 (54.3%), 28 (10.4%), and 4 (1.5%) belonged to P. falciparum, P. vivax, and mixed infections, respectively. All febrile patients were also tested for ABO blood groups and 51.3%, 23.5%, 21.9% and 3.3% were found to be blood types of O, A, B and AB, respectively. Both total malaria infection and P. falciparum infection showed significant association with blood types (P<0.05). The proportion of A or B but not O phenotypes was higher (P<0.05) in individuals with P. falciparum as compared with non-infected individuals. The chance of having P. falciparum infection in patients with blood groups A, B and AB was 2.5, 2.5 and 3.3 times more than individuals showing blood O phenotypes, respectively. The mean P. falciparum malaria parasitaemia for blood groups A, B, AB, and O were 3 744/µL, 1 805/µL, 5 331/µL, and 1 515/µL, respectively (P<0.01).

Conclusions

The present findings indicate that individuals of blood groups A, B and AB are more susceptible to P. falciparum infection as compared with individuals of blood group O. Nevertheless, further in depth studies are required to clearly establish the role that ABO blood group plays in P. falciparum malaria.     

Newborn colonization and antibiotic susceptibility patterns of <Emphasis Type="Italic">Streptococcus agalactiae</Emphasis> at the University of Gondar Referral Hospital,Northwest Ethiopia

Background

Group B Streptococcus (GBS) that asymptomatically colonizing the recto-vaginal area of women is the most important cause of neonatal colonization. There is paucity of evidence about newborn colonization with GBS in Ethiopia. Thus, this study was aimed to determine the prevalence of newborn colonization with GBS, antibiotic susceptibility patterns of the isolates and associated risk factors at the University of Gondar Referral Hospital in Northwest Ethiopia

Methods

A prospective cross sectional study was conducted from December 2016 to November 2017. A total of 1,155 swabs from nasal, ear and umbilical areas of the newborns were collected from the 385 newborns. Identifications of the isolates and antibiotic susceptibility testing were done by using conventional methods.

Results

Sixty two (16.1%, 95% CI: 12.2% - 20%) of the newborns were colonized by GBS. Seven percent of the total specimens were positive for GBS. The antibiotics susceptibility rates of GBS (average of the three body sites tested) were 95.1%, 89.6%, 88.9%, 85.7%, 85.3%, 81.3%, 76.9%, 76.1%, 73.8%, and 34.4% to ampicillin, penicillin, ciprofloxacin, chloramphenicol, vancomycin, azitromycin, erythromycin, clindamycin, ceftriaxone, and tetracycline, respectively. A multilogistic regression analyses were shown that the newborns that were from mothers whose education status was below tertiary level, and newborns from mothers who were: being employed, being nullipara and multigravida were at risk for colonization with GBS.

Conclusion

Prevalence of neonatal colonization with GBS was higher than it was reported in three decades ago in Ethiopia. Ciprofloxacin, chloramphenicol, vancomycin and azithromycin were identified as the drug of choice next to ampicillin and penicillin.