Mycobacterium tuberculosis curli pili (MTP) is associated with significant host metabolic pathways in an A549 epithelial cell infection model and contributes to the pathogenicity of Mycobacterium tuberculosis.

INTRODUCTION: A clear understanding of the metabolome of Mycobacterium tuberculosis and its target host cell during infection is fundamental for the development of novel diagnostic tools, effective drugs and vaccines required to combat tuberculosis. The surface-located Mycobacterium tuberculosis curli pili (MTP) adhesin forms initial contact with the host cell and is therefore important for the establishment of infection. OBJECTIVE: The aim of this investigation was to determine the role of MTP in modulating pathogen and host metabolic pathways in A549 epithelial cells infected with MTP proficient and deficient strains of M. tuberculosis. METHODS: Uninfected A549 epithelial cells, and those infected with M. tuberculosis V9124 wild-type strain, Δmtp and the mtp-complemented strains, were subjected to metabolite extraction, two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) and bioinformatic analyses. Univariate and multivariate statistical tests were used to identify metabolites that were significantly differentially produced in the WT-infected and ∆mtp-infected A549 epithelial cell models, comparatively. RESULTS: A total of 46 metabolites occurred in significantly lower relative concentrations in the Δmtp-infected cells, indicating a reduction in nucleic acid synthesis, amino acid metabolism, glutathione metabolism, oxidative stress, lipid metabolism and peptidoglycan, compared to those cells infected with the WT strain. CONCLUSION: The absence of MTP was associated with significant changes to the host metabolome, suggesting that this adhesin is an important contributor to the pathogenicity of M. tuberculosis, and supports previous findings of its potential as a suitable drug, vaccine and diagnostic target.

Mycobacterium tuberculosis curli pili (MTP) deficiency is associated with alterations in cell wall biogenesis, fatty acid metabolism and amino acid synthesis.

INTRODUCTION: In an effort to find alternative therapeutic interventions to combat tuberculosis, a better understanding of the pathophysiology of Mycobacterium tuberculosis is required. The Mycobacterium tuberculosis curli pili (MTP) adhesin, present on the surface of this pathogen, has previously been shown using functional genomics and global transcriptomics, to play an important role in establishing infection, bacterial aggregation, and modulating host response in vitro and in vivo. OBJECTIVE: This investigation aimed to determine the role of MTP in modulating the metabolism of M. tuberculosis, using mtp gene-knockout mutant and complemented strains. METHODS: Untargeted two-dimensional gas chromatography time-of-flight mass spectrometry, and bioinformatic analyses, were used to identify significant differences in the metabolite profiles among the wild-type, ∆mtp mutant and mtp-complemented strains, and validated with results generated by real-time quantitative PCR. RESULTS: A total of 28 metabolites were found to be significantly altered when comparing the ∆mtp mutant and the wild-type strains indicating a decreased utilisation of metabolites in cell wall biogenesis, a reduced efficiency in the breakdown of fatty acids, and decreased amino acid biosynthesis in the former strain. Comparison of the wild-type to mtp-complement, and ∆mtp to mtp-complemented strains revealed 10 and 16 metabolite differences, respectively. Real-time quantitative PCR results supported the metabolomics findings. Complementation of the ∆mtp mutant resulted in a partial restoration of MTP function. CONCLUSION: The lack of the MTP adhesin resulted in various bacterial cell wall alterations and related metabolic changes. This study highlights the importance of MTP as a virulence factor and further substantiates its potential use as a suitable biomarker for the development of diagnostic tools and intervention therapeutics against TB.

Spectrum of disease and outcome of primary amputation for diabetic foot sepsis in rural KwaZulu-Natal.

BACKGROUND: Primary amputation (stump closure) for diabetic foot sepsis is perceived to have a higher re-amputation rate due to stump sepsis. A guillotine amputation with elective stump closure is widely practised due to the lower risk of stump sepsis and re-amputation. AIMS: To provide an epidemiological analysis of the spectrum of disease and outcomes of primary amputation for diabetic foot sepsis in a regional rural hospital. METHODS: A prospective cohort study of 100 patients who underwent surgery for diabetic foot sepsis over a 5-year period was undertaken at Madadeni Provincial Hospital, in northern KwaZulu-Natal. Demographic data, co-morbid profile, radiographic features, anatomical level of vascular occlusion and type of surgery performed were recorded. The Wagner classification (Wag) was used to classify disease severity. Outcome measures included length of hospital stay, in-hospital mortality and re-amputation rates. RESULTS: Of the 100 patients, females (n = 50) accounted for 50% of admissions. The median age was 61 years (range: 29 to 80 years). Most patients presented with advanced disease: Wag 5, n = 71 (71%); Wag 4, n = 20 (20%); Wag 3, n = 7 (7%); Wag 2, n = 2 (2%). The anatomic levels of vascular occlusion comprised: aortoiliac disease n = 2 (2%), femoropopliteal n=21(21%) and tibioperoneal disease n = 77 (77%). The following surgical procedures were undertaken: above knee amputation (AKA), n = 35 (35%); below knee amputation (BKA), n = 46 (46%); transmetatarsal amputation (TMA), n = 8 (8%); toe ectomy, n = 8 (8%) and debridement, n = 3 (3%). The re-amputation rate to above knee amputation was n = 2/46 (4.3%). All AKA stumps healed completely. The overall in-hospital mortality was n = 7 (7%) and median length of hospital stay was 7.8 ± 3.83 days. CONCLUSION: Most patients present with advanced disease requiring a major amputation. A definitive one stage primary amputation is a safe and effective procedure for diabetic foot sepsis with distinct advantages of a short hospital stay, low reamputation rates and mortality. A guillotine amputation should be reserved for physiologically unstable patients.

Endovascular Therapy for Large Vessel Vasculopathy in HIV-infected Patients.

OBJECTIVES: To evaluate outcomes after endovascular treatment of patients with aneurysmal or occlusive vasculopathy in HIV-infected patients. METHODS: Retrospective analysis of a prospective database of treatment outcomes in patients with HIV related vasculopathies between April 2005 and September 2015. RESULTS: Sixty HIV patients presented with post-traumatic pseudoaneurysm formation (n = 7), aneurysmal disease (n = 24) or occlusive disease (n = 29 (48%)). The majority were male (42/60 (70%)), with a mean age of 43.9 years (SD ± 12.6). All seven patients with a post-traumatic pseudoaneurysm were treated by insertion of a covered stent (n = 6) or coiling (n = 1). All were successfully treated at 30 days, but only one patient returned for late surveillance. 23/24 patients who underwent insertion of a stent graft/covered stent for aneurysmal disease returned for 30 day review (one asymptomatic stent graft occlusion). Only 11 patients attended for late surveillance; 9/11 were asymptomatic with patent stent grafts. Late stent occlusion occurred in two (no further action (n = 1), major limb amputation (n = 1). In the 29 patients who underwent endovascular treatment for occlusive disease, 9 (31%) had immediate treatment failure (including 8 amputations (28%)). Of the sixteen who returned for serial review, 8 (50%) suffered further complications including 4 amputations. Overall, 12/29 treated patients (41%) ultimately underwent amputation. CONCLUSIONS: In the immediate short term, an 'endovascular first' strategy was associated with good outcomes in HIV patients with aneurysmal disease. By contrast, outcomes were poor in HIV patients with occlusive disease. Whether this relates to the underlying natural history of HIV occlusive vasculopathies remains unclear. One major problem in trying to formulate meaningful management strategies is a generalised reluctance for HIV patients to return for surveillance.

The sensitivity and specificity of subjective memory complaints and the subjective memory rating scale, deterioration cognitive observee, mini-mental state examination, six-item screener and clock drawing test in dementia screening.

BACKGROUND: The effectiveness of dementia screening depends on the availability of suitable screening tools with good sensitivity and specificity to confidently distinguish normal age-related cognitive decline from dementia. The aim of this study was to evaluate the discriminant validity of 7 screening measures for dementia. METHODS: A sample of 140 participants aged ≥60 years living in a residential facility for the aged were assessed clinically and assigned caseness for dementia using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revised diagnostic criteria. Sensitivity and specificity of a selection of the following screening measures were tested using receiver operating characteristic (ROC) analysis for individual and combined tests: the Mini-Mental State Examination (MMSE), Six-Item Screener (SIS), Subjective Memory Complaint, Subjective Memory Complaint Clinical (SMCC), Subjective Memory Rating Scale (SMRS), Deterioration Cognitive Observee (DECO) and the Clock Drawing Test (CDT). RESULTS: Using ROC analyses, the SMCC, MMSE and CDT were found to be 'moderately accurate' in screening for dementia with an area under the curve (AUC) >0.70. The AUCs for the SIS (0.526), SMRS (0.661) and DECO (0.687) classified these measures as being 'less accurate'. At recommended cutoff scores, the SMCC had a sensitivity of 90.9% and specificity of 45.7%; the MMSE had a sensitivity of 63.6% and a specificity of 76.0%, and the CDT had a sensitivity of 44.4% and a specificity of 88.9%. Combining the SMCC and MMSE did not improve their predictive power except for a modest increase when using the sequential rule. CONCLUSION: The SMCC is composed of valid screening questions that have high sensitivity, are simple to administer and ideal for administration at the community or primary health care level as a first level of 'rule-out' screening. The MMSE can be included at a second stage of screening at the general hospital level and the CDT in specialist clinical settings. Sequential use of the SMCC and MMSE will improve the specificity of the former and the sensitivity of the latter.

Decision-making in the ICU: An analysis of the ICU admission decision-making process using a '20 Questions' approach.

Background: Deciding to admit a patient into the intensive care unit (ICU) is a high-stakes, high-stress, time-sensitive process. Elucidating the complexities of these decisions can contribute to a more efficient, effective process. Objectives: To explore physicians' strategic thought processes in ICU triage decisions and identify important factors. Methods: Practitioners (N=29) were asked to decide on ICU referrals of two hypothetic cases using a modified '20 Questions' approach. Demographic data, decisions when full information was available, feedback on questions, rating of factors previously identified as important and influence of faith and personality traits were explored. Results: Of the 735 questions asked, 95.92% were patient related. There were no significant differences in interview variables between the two cases or with regard to presentation order. The overall acceptance rate was 68.96%. Refusals were associated with longer interview times (p=0.014), as were lower ICU bed capacity (p=0.036), advancing age of the practitioner (p=0.040) and a higher faith score (p=0.004). Faith score correlated positively with the number of questions asked (p=0.028). There were no significant correlations with personality trait stanines. When full information was available, acceptances for Case A decreased (p=0.003) but increased for Case B (p=0.026). The net reclassification improvement index was -0.138 (p=0.248). Non-subspecialists were more likely to change their decisions (p=0.036). Conclusion: Limiting information to what is considered vital by using a '20 Questions' approach and allowing the receiving practitioner to create the decision frame may assist with ICU admission decisions. Practitioners should consider the metacognitive elements of their decision-making. Contributions of the study: The study used a novel approach to explore physicians' decision-making process for admitting a patient to the intensive care unit (ICU). Understanding the main factors that influence the decision-making process will allow for streamlining the referral process, more effective selection of patients most likely to benefit from ICU treatment, and prevent inappropriate admissions into the ICU. The findings can also help to improve data capture tools and encourage practitioners to critically reflect on their decision-making processes.

Extra-adrenal paraganglioma: presentation in three uncommon locations.

Extra-adrenal paragangliomata are uncommon entities. They can be classified into four basic groups according to their anatomical sites, i.e. branchiomeric, intravagal, aorticosympathetic and visceral autonomic. Similar tumours may arise in sites away from the usual distribution of the sympathetic and parasympathetic ganglia, e.g. orbit, nose, small intestine and even in the pancreas. We report three instructive cases of extra-adrenal paraganglioma which were found in unusual sites such as urinary bladder, thyroid gland and on the wall of the inferior vena cava.

Fluctuating pulse deficits associated with intimal arterial injury following gunshot wounds of the extremity--a sign not to be missed.

Gunshot wounds may result in intimal arterial injury without breach of the arterial wall integrity. Haemorrhage, haematoma and a pulse deficit are therefore not always found. We report on two cases of lower extremity gunshot wounds with temporal variations in the clinical and radiological assessment of the pedal pulses. In both cases surgical exploration revealed intact arterial vessel walls but significant intimal injury with overlying thrombus. We propose that the pulse deficits were due to distal thromboembolism. Subsequent clot lysis led to a return of the original pulse deficit. Variation in the distal pulses in patients with gunshot wounds of the extremities should alert one of the possibility of an intimal arterial injury; imaging of the vessels is therefore advised.

Relatedness of Thermomyces lanuginosus strains producing a thermostable xylanase.

Properties of an endo-beta-xylanase produced by a locally isolated Thermomyces lanuginosus strain SSBP was compared to seven other T. lanuginosus strains isolated from different geographical regions. Strain SSBP produced the highest xylanase activity of 59600 nkat ml(-1) when cultivated on corn cobs (maize) medium, whereas the seven other strains produced xylanase activities ranging from 6000 to 32000 nkat ml(-1). No cellulase activity was produced by the strains. Despite the variability in the production of xylanase, little difference in the other characteristics of the strains could be found. The optimal temperature and pH for xylanase production by the strains was either 40 or 50 degrees C and between pH 6 and 7, respectively. Optimal xylanase activity of the strains was observed at 70 degrees C and at pH 6 or 6.5. Culture supernatant analysis by SDS-PAGE and isoelectric focusing PAGE of all strains revealed the presence of a single 24.7 kDa and pI 3.9 xylanase. Phylogenetic analysis by PCR amplification and sequencing of the internal transcribed spacer of nuclear rRNA repeat units and 5.8S rDNA revealed no strain diversity. However, random amplified polymorphic DNA analysis pointed to greater diversity and with one primer (5'-GCCCGACGCG-3'), a relationship was established between xylanase levels and the RAPD pattern.

Linear rate of change in the product of erythrocyte water content and potassium concentration during the 0-120-hour postmortem period in the rat.

An accurate and reproducible technique was employed for measurement of water content (RBCH2O) and potassium concentration (RBCK) in rat erythrocytes post mortem. Coefficients of variation for determination of RBCH2O and RBCK, as estimated from the results of duplicate analyses (n = 36), were 1.21% and 1.17%, respectively. Erythrocyte water content and RBCK were directly and linearly related (r = +0.93 (P less than 0.001], while the product of RBCH2O and RBCK varied linearly and inversely (r = -0.89 (P less than 0.001] with postmortem interval (PMI) over the 0-120-h postmortem period. In addition, the standard deviations of the data points for (RBCH2O X RBCK) remained relatively constant and independent of PMI. Attention is drawn to the possibility of determining time elapsed since death from (sequential) measurements of (RBCH2O X RBCK) in individual cadavers.

Haloalkane and haloacid dehalogenases from aerobic bacterial isolates indigenous to contaminated sites in Africa demonstrate diverse substrate specificities.

Five bacteria were isolated from contaminated sites in Nigeria and South Africa using the culture enrichment technique. They were subjected to standard cultural, biochemical and microbiological techniques and identified to be species of Bacillus, Burkholderia, Corynebacterium, Micrococcus and Pseudomonas. Axenic cultures of the bacterial isolates utilized 1,2-dichloroethane (1,2-DCE) as the sole carbon source up to a final substrate concentration of 10 mM. Their mean generation time in 1,2-DCE ranged significantly (P<0.05) from 9.77 to 15.72 h with the maximum chloride release ranging between 59% and 86%. All the bacterial isolates produced two different dehalogenases, viz. one which is heat labile and specific for halogenated alkanes with optimum activity at a pH of 7.5 and the other which is more heat stable with a higher pH optimum of 9.0 and specific for halogenated alkanoic acids. However, the two enzyme types when tested demonstrated wide substrate specificities. It is therefore adjudged that these organisms may play a vital role in the bioremediation of sites polluted with chlorinated hydrocarbons.

Parasuicide in a general hospital in South Africa.

The study examined parasuicide behaviour in black (people of African origin) South Africans. The subjects comprised 51 cases of parasuicide, with a mean age of 23.5 yr. (the majority being women), referred over a one-year period. For most patients it was the first parasuicide attempt, and the majority used methods of self-poisoning. In addition, they were mostly single and had experienced early parental loss.

Cytopathologic changes associated with intrauterine contraceptive devices. A review of cervico-vaginal smears in 350 women.

Cervico-vaginal smears from 350 IUCD users were analysed to ascertain the range of abnormalities induced in the genital tract of these women. Alteration of the microbial environment, inflammatory, degenerative, reparative and proplastic epithelial changes were the salient cytological findings. The clinical implications of these are briefly discussed.

PIP: Researchers examined results of cervico-vaginal smears of 350 women aged 23-45 years fitted with IUDs at various family planning clinics in Kuala Lumpur, Malaysia, to examine abnormalities in their genital tract. All the women had undergone preinsertion cervico-vaginal smears. They used the IUD for 1-8 years. Around 66% exhibited symptoms after IUD insertion. 40% had vaginal discharge, especially mucous. 3% had pelvic pain and intermittent low grade fever, suggesting pelvic inflammatory disease. 80% had an increase in the number of leukocytes in their blood. 42% had an increase in the number of histiocytes with multinucleate giant forms. The following microorganisms were present: Gardnerella vaginalis (42%), Trichomonas vaginalis (32%), Candida (28%), Actinomyces-like organisms (2%), and non-pathogenic Amoeba (0.6%). Both endocervical and squamous columnar cells exhibited morphological atypias (inflammatory, degenerative, or reparative changes). 70% of atypias were benign and varied from mild to severe. 14 women (4%) had cervical intra-epithelial neoplasia (CIN). 3% of the women had atypical single cells. The IUDs were removed from all of these women. 6 months after IUD removal, the cervixes with mild dysplasia had reverted to normal. Two women with severe dysplasia underwent cervical biopsy, which revealed a CIN III lesion. 28% of smears had abnormal or irritated glandular epithelial endocervical and endometrial cells with hyperchromatic nuclei, an increased nucleo-cytoplasmic ratio, and bubble-gum vacuolation of the cytoplasm. 31% of the women had normal or inflamed out-of-phase (beyond day 11 of the menstrual cycle) endometrial cells. 80% of these 109 women had menorrhagia or intermenstrual bleeding. The researchers recommend that serious epithelial atypias be followed up and the IUD be removed. IUD removal allows clinicians to determine whether atypias will regress in the absence of an IUD or are truly neoplastic.

Post-menopausal smear patterns--a review of vaginal smears in 480 women.

Cytohormonal evaluation was done on the vaginal smears of 480 normal, asymptomatic, post-menopausal women whose ages ranged from 36 to 74 years. About 50% showed atrophic smears consistent with total oestrogen lack. 41% had mild to moderately proliferative smears compatible with sub-optimal oestrogen stimulus. 9% showed a highly proliferative pattern typical of unopposed oestrogen effect and in this group two women had atypical endometrial cells in their smears, which subsequently were found to come from an atypical endometrial hyperplasia and an endometrial adenocarcinoma-in-situ. The clinical relevance of cytohormonal studies in post-menopausal women is briefly discussed.

Trichomoniasis--incidence in pill users and associated Pap smear abnormalities.

PIP: The occurrence of Trichomonas vaginalis in pill users and nonusers was studied by examining 1163 cervico vaginal smears. There were twice as many pill users as nonusers and a significant number of asymptomatic carriers. The cytologic findings ranged from normal through inflammatory and dyskaryotic changes to those with malignant features. The majority, however, belonged to the benign end of the spectrum of epithelial atypias. Significant observations are that the greater incidence of Trichomoniasis in pill users and the presence of persistent epithelial dyskaryosis in about 8% of the cases.^ieng

The distinction of malingering and mental illness in black forensic cases.

The ability of twenty items to separate malingering from mental illness is tested. The items were obtained from the literature and clinical experience. The study used an experimental, cross-sectional design which compared fifty malingering African patients and a control group of fifty African State Presidents' Detainees. The chi-square test and the Fisher's exact test were used to assess statistical significance. The effectiveness of these items was assessed by calculating their sensitivity, specificity, false positives and negatives and positive and negative predictive values. Seventeen items showed statistical significance. Eleven items had high positive predictive values mostly above 90% with four items scoring 100%. These diagnosed malingering effectively. Another six items had high negative predictive values mainly above 90%. These diagnosed mental illness directly and excluded malingering effectively. The study proved that seventeen items can scientifically and effectively separate mental illness from malingering.

Vascular injuries following blunt polytrauma.

INTRODUCTION: Motor vehicle collisions account for the majority of blunt vascular trauma. Much of the literature describes the management of these injuries in isolation, and there is little information concerning the incidence and outcome in patients suffering multiple trauma. This study was undertaken to describe the spectrum of blunt vascular injuries in polytrauma patients. PATIENTS AND METHODS: All patients who had sustained blunt vascular trauma over a 6-year period (April 2007-March 2013) were identified from a prospectively gathered database at the Level I Trauma Unit, Inkosi Albert Luthuli Central Hospital, Durban, South Africa. The retrieved data consisted of age, sex, mechanism of injury, referral source, Injury Severity Score (ISS), New Injury Severity Score (NISS), time from injury to admission, surgical intervention and outcome. The initial investigation of choice for patients sustaining multiple injuries was computed tomography (CT) angiography if they were physiologically stable, followed by directed angiography if there was doubt concerning any vascular lesion. If technically feasible, endovascular stenting was the preferred option for both aortic and peripheral vascular injuries. RESULTS: Of 1,033 patients who suffered blunt polytrauma, 61 (5.9 %) sustained a total of 67 blunt vascular injuries. Motor vehicle collisions accounted for 92 % of the injuries. The median ISS was 34 [interquartile range (IQR) 24-43]. The distribution of blunt vascular injuries was extremity (21), thorax (20), abdomen and pelvis (19), and head and neck (7). Endovascular repair was employed in 12 patients (ten blunt aortic injury, one carotid-cavernous sinus fistula, one external iliac artery). Of the extremity injuries, primary amputation was undertaken in 8 (38.1 %) and secondary amputation in 2 (9.5 %). The total amputation rate was 48 %. There were 17 (28.3 %) deaths, of which 11 (64.7 %) were directly attributable to the vascular injury and 6 (35.3 %) of these occurred on the operating table from exsanguination, the majority from injuries to the abdominal vena cava. CONCLUSIONS: Blunt vascular injury is uncommon in the patient with multiple trauma but confers substantial morbidity and mortality. In those cases with peripheral injuries, delays in referral to definitive care frequently exceed the ischaemic time, resulting in a high rate of amputations. Central injuries, especially those of the vena cava, account for the majority of directly attributable deaths.

Mild cognitive impairment and dementia in a heterogeneous elderly population: prevalence and risk profile.

OBJECTIVE: To describe the demographic, clinical and risk profile of Mild Cognitive Impairment and dementia in a sample of elderly South Africans within a residential setting. METHOD: One hundred and forty participants residing in a group of residential homes for the elderly were assessed by psychiatrists and assigned diagnoses of dementia or Mild Cognitive Impairment (MCI). Participants diagnosed with dementia were also offered haematological investigations and a CT scan of the brain. RESULTS: The sample consisted of 140 participants comprising 46.4% White, 29.3% Coloured, 20% Asian and 4.3% Black participants. There were 97 (69.3%) females and 106 (75.7%) participants had less than 12 years of education. Eleven (7.9%) dementia and 38 (27.1%) MCI cases were diagnosed. Increasing age was associated with cognitive impairment (MCI and dementia) (p=.020) but there was no association between gender and cognitive impairment (p=.165). MCI was significantly associated with a lower education level (p=.036) and no association was found between depression (current-p=.646; past-p=.719) and dementia or MCI. The presence of vascular risk factors (n=140) ranged from 66.4% (hypertension) to 14.3% (stroke). Subjective memory complaints were significantly associated with cognitive impairment (p=.001). Except for the use of the telephone (p=.225) and the television (p=.08), impairment in all domains of instrumental activities of daily living that were assessed were significantly associated with a dementia diagnosis. CONCLUSION: The study showed that cognitive impairment was associated with increasing age and low education levels. The presence of vascular risk factors places this population at risk for future cognitive decline.