Revisiting therapeutic hypothermia for severe traumatic brain injury... again.

Improved understanding of the molecular mechanisms of secondary brain injury has informed the optimum depth and duration of cooling and led to increased clinical interest in the therapeutic moderate hypothermia for severe traumatic brain injury over the past two decades. Although several large multi-center clinical trials have not found a treatment effect, multiple single-center trials have, and a recent meta-analysis by Crossley and colleagues now finds that the cumulative findings of those single-center trials dilute the multi-center trial results and show an overall reduction in mortality and poor outcomes associated with cooling. The need for consistent support of key physiologic parameters during cooling is emphasized by this finding.

The first population-based national tuberculosis prevalence survey in Ethiopia, 2010-2011.

SETTING: Tuberculosis (TB) remains a major public health problem in Ethiopia. OBJECTIVE: To determine the prevalence of pulmonary TB among the general adult population aged ≥15 years in 2010-2011. METHOD A nationwide, cluster-sampled, stratified (urban/rural/pastoralist), cross-sectional survey was conducted in 85 selected clusters. All consenting participants were screened for TB using: 1) chest X-ray (CXR) and 2) an interview to screen for symptoms suggestive of TB disease. RESULT: Of 51,667 eligible individuals, 46,697 (90%) participated in the survey and completed at least the screening interview. CXR was performed among 46,548 (99.7%) participants. A total of 6080 (13%) participants were eligible for sputum examination. From the survey, it was estimated that in the national adult population 1) the prevalence of smear-positive TB was 108/100,000 (95%CI 73-143), and 2) that of bacteriologically confirmed TB was 277/100,000 (95%CI 208-347). CONCLUSION: We found that the TB burden was lower than previously thought, which may indicate better programme performance. However, a high proportion of TB among young persons suggests that TB is circulating in the community and that there is a need for more efforts to limit the spread of TB disease.

Phenotypic and genotypic analysis of multidrug-resistant tuberculosis in Ethiopia.

SETTING: National Tuberculosis Reference Laboratory, Addis Ababa, Ethiopia. OBJECTIVES: To determine the drug susceptibility pattern of Mycobacterium tuberculosis isolates and to genetically characterise multidrug-resistant tuberculosis (MDR-TB) isolates. DESIGN: A total of 107 M. tuberculosis isolates recovered during the period December 2005-August 2006 were tested for drug susceptibility against streptomycin, isoniazid, rifampicin and ethambutol (SHRE) using the proportion method on Löwenstein-Jensen medium. The MDR-TB isolates were tested against kanamycin, ciprofloxacin, capreomycin, D-cycloserine and ethionamide. Genotyping was performed using spoligotyping. RESULTS: MDR-TB was observed in one of the 44 new cases (2.3%) and 45/63 previously treated patients (71.4%). Drug susceptibility testing against second-line drugs (SLDs) showed that 26.1% of all MDR-TB isolates were susceptible to all SLDs tested and 73.9% were resistant to one or more classes of SLD. Extensively drug-resistant (XDR) TB was detected in two isolates (4.4%). T3_ETH was the predominant spoligotype, followed by CAS_KILI. In this African setting, no Beijing spoligotype was identified. CONCLUSION: Both MDR- and XDR-TB are present in Ethiopian patients. MDR-TB was found to be associated with T3 and Central Asian genotypes.

Microscopic-observation drug susceptibility assay provides rapid and reliable identification of MDR-TB.

BACKGROUND: Liquid culture systems are more rapid and sensitive for both the detection and drug susceptibility testing (DST) of Mycobacterium tuberculosis. SETTING: St Peter's TB Specialised Hospital and public health laboratory, Addis Ababa. OBJECTIVE: To compare the microscopic-observation drug susceptibility (MODS) assay with the BACTEC-MGIT 960 system for isoniazid and rifampicin DST (i.e., multidrug-resistant tuberculosis [MDR-TB] identification) of M. tuberculosis. DESIGN: The evaluation was based on 58 smear- and culture-positive sputum samples from patients diagnosed in Addis Ababa, Ethiopia. BACTEC-MGIT was used as the reference standard. RESULTS: For the detection of MDR-TB, MODS has a sensitivity, specificity and accuracy rate of respectively 95%, 100% and 98.3% (kappa 0.981, concordance 98.3%). Concurrent culture detection and DST results are obtained in a median of 9 days with MODS, while indirect DST results with BACTEC-MGIT are obtained in a median of 8 days (this does not include time to primary isolate). CONCLUSION: MODS is an accurate, rapid and relatively inexpensive method for the identification of MDR-TB.

Drug susceptibility of Mycobacterium tuberculosis in HIV-infected and -uninfected Ethiopians and its impact on outcome after 24 months of follow-up.

From a prospective cohort study on tuberculosis/human immunodeficiency virus (TB/HIV) interaction in Addis Ababa, Ethiopia, drug susceptibility results were available for 94 TB patients (46% HIV-infected). Resistance to one or more drug(s) was detected in 21 (22.3%) and multidrug resistance in five (5.3%) patients. Occurrence of resistance was not related to HIV status or outcome after 24 months of follow-up. However, among HIV-infected TB patients who died during follow-up, survival time in those with a resistant Mycobacterium tuberculosis strain was significantly shorter compared to those with a sensitive strain (6 vs. 13 months). Early detection of drug resistance and timely treatment change can therefore have a positive impact on survival in HIV-infected TB patients.

Evaluation of abattoir inspection for the diagnosis of Mycobacterium bovis infection in cattle at Addis Ababa abattoir.

Detailed postmortem examinations were conducted to evaluate the efficiency of meat inspection procedures and to determine the distribution of lesions in Mycobacterium bovis-infected cattle. The study involved routine inspection at slaughter, collection of tissues for detailed examination in the laboratory, and bacteriological examination to identify M. bovis. Additionally, a 10-year (1992--2001) meat inspection record was analysed to determine tuberculosis trends in the past decade. chi2-Test and simple regression were used to analyse the data. Out of 1350 cattle examined, 1.5% were found with tuberculous lesions. Routine abattoir inspection detected only 55% of cattle with confirmed lesions. Fifty-four per cent of tuberculous lesions were found in the lungs and thoracic lymph nodes, 23% in the lymph nodes of the head, and the remaining 23% in the mesenteric and other lymph nodes of the carcase. M. bovis was additionally isolated from an animal that had no gross lesions of tuberculosis. On average, the annual rate of whole-carcase condemnation due to generalized tuberculosis was 0.024% and it has increased annually by 0.34% over the past decade. The rate of whole-carcase condemnation indicates a high degree of TB transmission and requires immediate attention from both the economic and public health points of view. The lower sensitivity of routine abattoir inspection confirms the importance of improving necropsy procedures.

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.

Sensitivity to anti-tuberculosis drugs in HIV-positive and -negative patients in Addis Ababa.

A cross-sectional survey was conducted between 1 August and 31 December, 1998 in Addis Ababa, Ethiopia to determine the rate of primary drug resistance to anti-tuberculosis drugs and to investigate its possible association with HIV infection. Sputum culture, sensitivity to first-line anti-tuberculosis drugs and HIV testing were done for 236 sputum smear-positive pulmonary tuberculosis patients. Primary drug resistance level (single or multidrug resistance) had not changed significantly since 1994. Primary resistance occurred more often among HIV-positive than among HIV-negative patients. The association between drug resistance and HIV will have a serious impact in the control of tuberculosis because in recent years the prevalence of HIV has increased dramatically in Ethiopia. Therefore, further studies on drug resistance and HIV infection and the establishment of drug resistance surveillance are recommended.

Attitude and social consequences of tuberculosis in Addis Ababa, Ethiopia.

OBJECTIVE: To gain a better understanding of the attitude and social consequences of tuberculosis (TB) in Addis Ababa, Ethiopia. DESIGN: A cross sectional survey using a structured questionnaire and a qualitative study based on the focus group discussion (FGD) technique. SETTING: Eight different kebeles (urban dwellers' associations) of six woredas (next higher administrative level to kebele). SUBJECTS AND METHODS: Seven hundred and three participants, comprising 326 males and 377 females were interviewed using the written questionnaire and 36 recent and current TB patients through focus group discussion. Data were analysed using SPSS/PC statistical package. The proportions were compared using univariate and bivariate analyses to show the frequency distribution and evaluate the relationship among different variables. In FGD, topics relevant to the research questions were identified, sorted and analysed. Conclusions were then formulated. MAIN OUTCOME MEASURES: Attitude of participants towards TB and its victims and social consequences of being a TB patient. RESULTS: Eighty three per cent of the respondents were aware that TB is a disease transmitted from one person to another and 80.1% perceived TB as an extremely severe disease. Of the total, 81.5% answered that TB is caused by cold, 69.0% feel that TB patients are not accepted in the community and 78.3% fear physical contact with TB patients. Most participants of the FGD sessions agreed that TB is a very dangerous, contagious but curable disease and the community has a generally negative attitude towards them. They also think that TB is associated with HIV/AIDS in the society. These attitudes have social consequences particularly the stigmatization and social isolation of TB patients. Four hundred and four (57.5%) respondents were found to be in favour of the short course chemotherapy against 226 (32.1%) choosing the longer course. Clinical improvement and unavailability of some drugs or their cost were the first and second main reasons indicated, respectively, for defaulting by respondents. CONCLUSION: The perception by most respondents that tuberculosis is incurable, transmittable and associated with HIV/AIDS, led to the understanding that TB is a very dangerous disease. This, in turn, contributes to social avoidance and the resultant consequences in TB patients. Health education must be stepped-up within the TB control programme, and the psychosocial implications of TB should be given due attention.

Properties of the menaquinol oxidase (Qox) and of qox deletion mutants of Bacillus subtilis.

Menaquinol oxidase isolated from the membrane of Bacillus subtilis W23 was found to consist of four polypeptides (QoxA, B, C, and D) that were predicted by the sequence of the qox operon of B. subtilis 168 (Santana et al. 1992). The preparation contained 7 mol cytochrome aa3 per g protein, which corresponds to 2 mol heme A per mol enzyme of 144 kDa molecular mass. Respiration with dimethylnaphthoquinol catalyzed by the enzyme was ten times faster than that with menadiol. Activities with more electropositive quinols were negligible. The activity of the enzyme was inhibited by equimolar amounts of HQNO, while antimycin, myxothiazol, and stigmatellin were more than tenfold less effective. When cells of both strains of B. subtilis (W23 and 168) were grown with glucose, quinol respiration was an order of magnitude more active than respiration with N,N,N',N'-tetramethyl-1,4-phenylenediamine plus ascorbate. Surprisingly, the same result was obtained with mutant strains lacking qoxB. As cytochromes a and d were virtually absent, a second quinol oxidase, possibly of the cytochrome o-type, was apparently formed by the mutants.

Fumarate reductase of Helicobacter pylori--an immunogenic protein.

An immunogenic protein with an apparent mol. wt of 80 kDa that was recognised by 55% of sera from patients infected with Helicobacter pylori in Western blots was found in butanol extracts of H. pylori membranes. The N-terminal amino-acid sequence of the 80-kDa protein showed 80% identity with the N-terminal sequence of subunit A of the fumarate reductase of Wolinella succinogenes, suggesting the existence of a fumarate reductase in H. pylori. The membrane fraction of H. pylori catalysed succinate oxidation with methylene blue at a specific enzyme activity of 0.06 U/mg of protein. The enzyme was purified by Triton X100 extraction followed by ion-exchange chromatography. The purified enzyme contained an 80-kDa protein which was recognised by rabbit serum raised against subunit A of fumarate reductase of W. succinogenes. A second protein band with a mol. wt of 31 kDa was recognised by rabbit serum raised against subunit B of fumarate reductase of W. succinogenes. Two-dimensional gel electrophoresis demonstrated that the 80- and 31-kDa proteins were subunits of one protein complex. These results indicate that H. pylori contains an enzyme that is very similar to W. succinogenes fumarate reductase. The 80-kDa subunit was recognised in sonicates of all 32 H. pylori strains tested by rabbit antibodies raised against subunit A of fumarate reductase of W. succinogenes, indicating that fumarate reductase is a common protein in H. pylori. The fumarate reductase of H. pylori might enable the bacterium to perform anaerobic respiration in a similar fashion to other anaerobic or facultative bacteria.

The menaquinol oxidase of Bacillus subtilis W23.

The quinol oxidase appears to be mainly responsible for the oxidation of the bacterial MKH2 in Bacillus subtilis W23 growing with either glucose or succinate. The activity of the enzyme was maximum with dimethylnaphthoquinol, a water-soluble analogue of the bacterial menaquinol. Menadiol or duroquinol were less actively respired, and naphthoquinol was not oxidized at all. After fourtyfold purification the isolated enzyme contained 5.3 mumol cytochrome aa3 per gram of protein and negligible amounts of cytochrome b and c. The turnover number based on cytochrome aa3 was about 10(3) electrons.s-1 at pH 7 and 37 degrees C. The preparation consisted mainly of a M(r) 57,000 and a M(r) 36,000 polypeptide. The N-terminal amino acid sequence of the latter polypeptide differed from that predicted by the qoxA gene of B. subtilis strain 168 (Santana et al. 1992), in that asp-14 predicted by qoxA was missing in the M(r) 36,000 polypeptide.

Comparative study of skin testing with PPD and new tuberculins by the WHO Mantoux test.

PPD RT 23 tuberculin and two batches of new tuberculin (NT) were tested for concordant skin indurations in the WHO standard Mantoux test in 11- to 13-year-old Finnish school children BCG vaccinated at birth. All were double tested with RT 23 and with either batch T1327 (614 children) or with batch T1456 (312 children) of NT. The results were compared with data available from an earlier study employing RT 23 and T1327 in Ethiopian children, 50/134 of whom had a BCG scar. The mean induration to RT 23 after 72 h was slightly smaller than to the NTs. The individual readings for RT 23 had significant linear correlations with T1327 in Finland (r = 0.77) and in Ethiopia (r = 0.89), and for T1456 (r = 0.83; P < 0.001 for all three). Zero reactions were much fewer to NTs (5.5% to T1327 and 0.3% to T1456) than to RT 23 in Finland (18.2% and 9.3% respectively for the two groups). The results were similar in Ethiopian children. Our results indicate that RT 23 and the two NTs give concordant results, but NTs seem to be more specific, perhaps because they retain more species-specific antigens. Analysis of our results suggests that different peaks in the distribution of reaction sizes were due to responses to different antigens or combinations of antigens, and in the case of the largest reactions, to a different type of immunological response.

Reactivity of the Bacillus subtilis succinate dehydrogenase complex with quinones.

The succinate dehydrogenase isolated from Bacillus subtilis was found to catalyze the oxidation of succinate with hydrophilic quinones. Either naphthoquinones or benzoquinones served as acceptors. The enzyme activity increased with the redox potential of the quinone. The highest turnover number was commensurate with that of the bacterial succinate respiration in vivo. The succinate dehydrogenase was similarly active in fumarate reduction with quinols. The highest activity was obtained with the most electronegative quinol. The fumarate reductase isolated from Wolinella succinogenes catalyzed succinate oxidation with quinones and fumarate reduction with the corresponding quinols at activities similar to those of the B. subtilis enzyme. Succinate oxidation by the lipophilic quinones, ubiquinone or vitamin K-1, was monitored as cytochrome c reduction using proteoliposomes containing succinate dehydrogenase together with the cytochrome bc1 complex. The activity with ubiquinone or vitamin K-1 was commensurate with the succinate respiratory activity of bacteria or of the bacterial membrane fraction. The results suggest that menaquinone is involved in the succinate respiration of B. subtilis, although its redox potential is unfavorable.

Menaquinone is an obligatory component of the chain catalyzing succinate respiration in Bacillus subtilis.

The question was investigated as to whether the bacterial menaquinone (MK) is a component of the electron transport chain catalyzing succinate respiration in Bacillus subtilis. Three different methods were applied, and the following consistent results were obtained. (i) Solvent extraction of MK from the bacterial membrane caused total inhibition of the respiratory activities with succinate and NADH, while the activity of succinate dehydrogenase remained unaffected. The respiratory activities were restored on incorporation of vitamin K1 into the membrane preparation. (ii) The membrane fraction of a B. subtilis mutant containing 15% of the wild-type amount of MK, respired succinate and NADH at reduced activities. Wild-type activities were restored on fusion of the preparation to liposomes containing vitamin K1. (iii) The membrane fraction of B. subtilis catalyzed succinate oxidation by various water-soluble naphtho- or benzoquinones at specific activities exceeding to that of succinate respiration. The results suggest that MK is involved in succinate respiration, although its redox potential is unfavorable.

Bacteriological studies of tuberculosis in Sidamo Regional Hospital.

All of the 104 strains isolated from tuberculosis patients in Sidamo Regional Hospital were identified as M. tuberculosis. Primary single drug resistance to isoniazid and streptomycin was represented by two strains in each case. Four strains showed double drug resistance to the same drugs. None were resistant to thiacetazone, rifampicin and ethambutol.

Inflammatory malignant fibrous histiocytoma of the kidney: an immunohistochemical and ultrastructural study.

A primary inflammatory malignant fibrous histiocytoma of the kidney is reported. The differential diagnosis from other sarcomas and pseudosarcomatous lesions is discussed on the grounds of the histologic, immunohistochemical and ultrastructural results. The neoplasm was made up of histiocytes, fibroblasts, myofibroblasts, foam cells and undifferentiated mesenchymal cells with admixed granulocytes, lymphocytes and plasma cells. The immunohistochemical study showed a positivity for alpha-1-antichymotrypsin and a weak positivity for alpha-1-antitrypsin in mononuclear and pleomorphic multinucleated tumor cells. PAS-positive, diastase-resistant intracytoplasmic hyaline globules in necrotic cells, examined by electron microscopy, most likely represent lysosomal structures, in accordance with the theories of De Duve, Vattiaux and Von Ardenne.