Low vision and blindness in adults in Gurage Zone,central Ethiopia

AIM: To determine the magnitude and causes of low vision and blindness in the Gurage zone, central Ethiopia. METHODS: A cross sectional study using a multistage cluster sampling technique was used to identify the study subjects. Visual acuity was recorded for all adults 40 years and older. Subjects who had a visual acuity of <6/18 were examined by an ophthalmologist to determine the cause of low vision or blindness. RESULTS: From the enumerated population, 2693 (90.8%) were examined. The prevalence of blindness (<3/60 better eye presenting vision) was 7.9% (95% CI 6.9 to 8.9) and of low vision (6/24-3/60 better eye presenting vision) was 12.1% (95% CI 10.9 to 13.3). Monocular blindness was recorded in 16.3% of the population. Blindness and low vision increased with age. The odds of low vision and blindness in women were 1.8 times that of the men. The leading causes of blindness were cataract (46.1%), trachoma (22.9%), and glaucoma (7.6%). While the prevalence of vision reducing cataract increased with age, the prevalence of trachoma related vision loss did not increase with age, suggesting that trichiasis related vision loss in this population might not be cumulative. CONCLUSION: The magnitude of low vision and blindness is high in this zone and requires urgent intervention, particularly for women. Further investigation of the pattern of vision loss, particularly as a result of trachomatous trichiasis, is warranted.     

A novel antibacterial iridoid and triterpene from Caiophora coronata

Bioassay-guided fractionation of the antibacterial CH(2)Cl(2)-MeOH extract obtained from the aerial parts of the Argentinean plant Caiophora coronata led to the isolation of a new triterpene, 1beta,3beta-dihydroxyurs-12-en-27-oic acid, 1, and a new iridoid, 1alpha-methoxy-6alpha,10-dihydroxyisoepiiridomyrmecin (caiophoraenin), 2, along with the known iridoid isoboonein 3. Their structures were established by spectroscopic techniques (1D and 2D NMR, HRFABMS, FTIR). The MIC values of isolated compounds were determined against methicillin-sensitive (MSSA) and -resistant (MRSA) strains of Staphylococcus aureus, Bacillus subtilis (BS), vancomycin-resistant Enterococcus faecium (VREF), Escherichia coli (EC), E. coli imp (ECimp), and Candida albicans (CA). Compound 1 was found active against BS, MSSA, MRSA, VREF, and ECimp with MIC values of 2, 4, 4, 4, and 16 microg/mL, respectively.     

The utility of pallor detecting anemia in under five years old children

The diagnosis and management of anemia, which affects a significant proportion of young children in developing countries, largely depends on the clinical assessment for pallor. This study was conducted with the aim of evaluating the utility of pallor in detecting anemia. Children aged 2 to 60 months who visited the pediatric outpatient department of Jimma Hospital over 3 months period were assessed for the presence and degree of pallor in 4 anatomic sites (conjunctivae, tongue and buccal mucosa, nailbeds, palm) by trained nurses. Hemoglobin was then determined using the HemoCue method. Individuals involved in clinical examination did not have access to the laboratory results before documenting their findings. The mean hemoglobin in the 574 children examined was 11.03 gm/dl, and about 46% had anemia. Children younger than 2 years were found to have a higher prevalence of anemia as compared to older children (p < 0.001). Palmar pallor, with a sensitivity of 58%, had the highest sensitivity to detect moderate anemia as compared to other anatomic sites. The presence of either palmar or conjunctival pallor increased the sensitivity to 73%. The inter-observer agreement was highest for conjunctival pallor (kappa value = 0.81). The findings of the study suggest that pallor of a single anatomic site does not have adequate sensitivity to detect moderate anemia. We recommend further studies to look at the performance of severe pallor in correctly identifying severe anemia. Furthermore, the magnitude and causes of anemia need to be studied in a community setting.     

Increase in tuberculosis incidence among the staff working at the Tuberculosis Demonstration and Training Centre in Addis Ababa, Ethiopia: a retrospective cohort study (1989-1998).

The incidence rate of tuberculosis was studied among the staff of the Tuberculosis Demonstration and Training Centre (TDTC) of Addis Ababa between 1989 and 1998, by reviewing all clinical charts of the 175 staff members for evidence of tuberculosis. During the study period, 24 cases of tuberculosis were diagnosed, including 12 who were bacteriologically confirmed. The incidence rate of tuberculosis increased from 1695 per 100000 person-years (py) in 1989 to 5556/100000 py in 1998 (test for trend, P < 0.001). Urgent measures are required for better protection of the staff from human immunodeficiency virus infection and tuberculosis.     

Renal aquaporin-4 associated pathology in TG-26 mice

Human immunodeficiency virus-associated nephropathy (HIVAN) is a leading cause of end-stage renal disease in HIV patients, which is characterized by glomerulosclerosis and renal tubular dysfunction. Aquaporin-4 (AQP-4) is a membrane bound water channel protein that plays a distinct role in water reabsorption from renal tubular fluid. It has been proven that failure of AQP-4 insertion into the renal tubular membrane leads to renal dysfunction. However, the role of AQP-4 in HIVAN is unclear. We hypothesize that impaired water reabsorption leads to renal injury in HIVAN, where AQP-4 plays a crucial role. Renal function is assessed by urinary protein and serum blood urea nitrogen (BUN). Kidneys from HIV Transgenic (TG26) mice (HIVAN animal model) were compared to wild type mice by immunostaining, immunoblotting and quantitative RT-PCR. TG26 mice had increased proteinuria and BUN. We found decreased AQP-4 levels in the renal medulla, increased endothelin-1, endothelin receptor A and reduced Sirtuin1 (SIRT-1) levels in TG26 mice. Also, oxidative and endoplasmic reticulum stress was enhanced in kidneys of TG26 mice. We provide the first evidence that AQP-4 is inhibited due to induction of HIV associated stress in the kidneys of TG26 mice which limits water reabsorption in the kidney which may be one of the cause associated with HIVAN, impairing kidney physiology. AQP-4 dysregulation in TG26 mice suggests that similar changes may occur in HIVAN patients. This work may identify new therapeutic targets to be evaluated in HIVAN.     

Binding of human von Willebrand factor to collagen and to collagen-stimulated platelets

Binding of von Willebrand factor (vWF) to collagen and to "collagen-stimulated platelets" was studied. Purified human iodine 125-labeled vWF binds to collagen. Binding was rapid, dependent on collagen and vWF concentration, independent of divalent ion concentration, and inhibited by unlabeled vWF as well as by high concentrations of fibronectin and fibrinogen. It was blocked by six monoclonal antibodies (MAbs) to human vWF (B200 through B205). Conversely, binding of 125I-vWF to platelets in the presence of collagen (collagen-treated platelets) was time dependent, saturable, and dependent on collagen, vWF, and divalent ion concentration. It was also inhibited by unlabeled vWF, fibronectin, or fibrinogen as well as by MAbs to vWF B200 through B205. In addition, binding of vWF to collagen-treated platelets was blocked by MAb to vWF 9 previously shown to inhibit binding of vWF to glycoprotein (GP) IIb-IIIa as well as by a MAb to GPIIb-IIIa. This binding was also strikingly decreased with use of patient platelets deficient in either GPIIb-IIIa or GPIa, whereas it was normal in the presence of a MAb to GPIb or when testing patient platelets deficient in GPIb. In conclusion, binding of vWF to platelets in the presence of collagen appeared to be a three-step phenomenon, including: binding of vWF to collagen; interaction of collagen with its receptor on the platelet membrane (GPIa ?), leading to activation of platelets and exposure of GPIIb-IIIa; and binding of vWF to GPIIb-IIIa.     

Epizootiological importance of Glossina morsitans submorsitans (Diptera: Glossinidae) (Newstead) in the Ghibe River Valley, Southwest Ethiopia

The epizootiological importance of Glossina morsitans submorsitans in Ghibe River Valley was undertaken from October 2000 to September 2001. The flies were collected using baited monoconical traps. G. m. submorsitans occurred with a mean apparent density of 4.26 ± 0.49 flies/trap/day and the apparent density was characterized by an increase during the wet season and a decrease during the dry season. Among 450 G. m. submorsitans, approximately 5% were found to be infected with trypanosome. Of these infected flies, 76% were female. Nanomonas, Duttonella and Trypanozoon were the three trypanosome subgenera detected and occurred in the proportions of 57.1%, 38.1% and 4.8%, respectively. Among 139 blood meals of G. m. submorsitans collected, 54.68% were identified to group or species levels. Accordingly, 36.84%, 25%, 11.84% and 10.53% accounted for cattle, kudu, suidae (warthog and/or wild pig) and human, respectively and others such as goats (6.58%), bovidae (5.26%), baboon (2.63%) and water buck (1.32%). While 21.05% of the blood meals were found to be out of detection range.     

Prognostic value of anti-ADAMTS 13 antibody features (Ig isotype, titer, and inhibitory effect) in a cohort of 35 adult French patients undergoing a first episode of thrombotic microangiopathy with undetectable ADAMTS 13 activity

To study both the pathophysiologic and the prognostic value of ADAMTS13 in thrombotic microangiopathies (TMAs), we enrolled a cohort of 35 adult patients combining a first acute episode of TMA, an undetectable (below 5%) ADAMTS13 activity in plasma, and no clinical background such as sepsis, cancer, HIV, and transplantation. All patients were treated by steroids and plasma exchange, and an 18-month follow-up was scheduled. Remission was obtained in 32 patients (91.4%), and 3 patients died (8.6%) after the first attack. At presentation, ADAMTS13 antigen was decreased in 32 patients (91.4%), an ADAMTS13 inhibitor was detectable in 31 patients (89%), and an anti-ADAMTS13 IgG/IgM/IgA was present in 33 patients (94%). The 3 decedent patients were characterized by the association of several anti-ADAMTS13 Ig isotypes, including very high IgA titers, while mortality was independent of the ADAMTS13 inhibitor titer. In survivors, ADAMTS13 activity in remission increased to levels above 15% in 19 patients (59%) but remained undetectable in 13 patients (41%). Six patients relapsed either once or twice (19%) during the follow-up. High levels of inhibitory anti-ADAMTS13 IgG at presentation were associated with the persistence of an undetectable ADAMTS13 activity in remission, the latter being predictive for relapses within an 18-month delay.