Molecular Epidemiology of Noninvasive and Invasive Group A Streptococcal Infections in Cape Town.

Group A streptococcus (GAS) is responsible for a wide range of noninvasive group A streptococcal (non-iGAS) and invasive group A streptococcal (iGAS) infections. Information about the emm type variants of the M protein causing GAS disease is important to assess potential vaccine coverage of a 30-valent vaccine under development, particularly with respect to how they compare and contrast with non-iGAS isolates, especially in regions with a high burden of GAS. We conducted a prospective passive surveillance study of samples from patients attending public health facilities in Cape Town, South Africa. We documented demographic data and clinical presentation. emm typing was conducted using CDC protocols. GAS was commonly isolated from pus swabs, blood, deep tissue, and aspirates. Clinical presentations included wound infections (20%), bacteremia (15%), abscesses (9%), and septic arthritis (8%). Forty-six different emm types were identified, including M76 (16%), M81 (10%), M80 (6%), M43 (6%), and M183 (6%), and the emm types were almost evenly distributed between non-iGAS and iGAS isolates. There was a statistically significant association with M80 in patients presenting with noninvasive abscesses. Compared to the 30-valent vaccine under development, the levels of potential vaccine coverage for non-iGAS and iGAS infection were 60% and 58%, respectively, notably lower than the coverage in developed countries; five of the most prevalent emm types, M76, M81, M80, M43, and M183, were not included. The emm types from GAS isolated from patients with invasive disease did not differ significantly from those from noninvasive disease cases. There is low coverage of the multivalent M protein vaccine in our setting, emphasizing the need to reformulate the vaccine to improve coverage in areas where the burden of disease is high.IMPORTANCE The development of a vaccine for group A streptococcus (GAS) is of paramount importance given that GAS infections cause more than 500,000 deaths annually across the world. This prospective passive surveillance laboratory study evaluated the potential coverage of the M protein-based vaccine currently under development. While a number of GAS strains isolated from this sub-Sahara African study were included in the current vaccine formulation, we nevertheless report that potential vaccine coverage for GAS infection in our setting was approximately 60%, with four of the most prevalent strains not included. This research emphasizes the need to reformulate the vaccine to improve coverage in areas where the burden of disease is high.

Participation in research improves overall patient management: insights from the Global Rheumatic Heart Disease registry (REMEDY).

BACKGROUND: Rheumatic heart disease (RHD) is a major public health problem in low- and middle-income countries (LIMCs), with a paucity of high-quality trial data to improve patient outcomes. Investigators felt that involvement in a recent large, observational RHD study impacted positively on their practice, but this was poorly defined. AIM: The purpose of this study was to document the experience of investigators and research team members from LMICs who participated in a prospective, multi-centre study, the global Rheumatic Heart Disease Registry (REMEDY), conducted in 25 centres in 14 countries from 2010 to 2012. METHOD: We conducted an online survey of site personnel to identify and quantify their experiences. Telephone interviews were conducted with a subset of respondents to gather additional qualitative data. We asked about their experiences, positive and negative, and about any changes in RHD management practices resulting from their participation in REMEDY as a registry site. RESULTS: The majority of respondents in both the survey and telephone interviews indicated that participation as a registry site improved their management of RHD patients. Administrative changes included increased attention to follow-up appointments and details in patient records. Clinical changes included increased use of penicillin prophylaxis, and more frequent INR monitoring and contraceptive counselling. CONCLUSION: Our study demonstrates that participation in clinical research on RHD can have a positive impact on patient management. Furthermore, REMEDY has led to increased patient awareness and improved healthcare workers' knowledge and efficiency in caring for RHD patients.

Tuberculosis surveillance in Cape Town, South Africa: an evaluation.

SETTING: Cape Town, South Africa. OBJECTIVE: To evaluate the current system of tuberculosis surveillance in the Cape Metro region. DESIGN: This evaluation was based on the 'Updated Guidelines for Evaluating Public Health Surveillance Systems' of the Centers for Disease Control and Prevention, modified to render the framework applicable to the context of tuberculosis (TB) surveillance. The evaluation incorporated qualitative exploration of perceptions and experiences of system users. RESULTS: System users were very accepting of the system and were committed to seeing it achieve its purpose within public health. Some individuals expressed concerns about the rigidity of the Electronic TB Register software and its analysis capabilities. Dissemination of TB data and evidence-based action within the Cape Metro region are strong attributes of Cape Town's TB surveillance system. At the time of the evaluation, integration of TB and human immunodeficiency virus (HIV) data was weak, as was multidrug-resistant TB (MDR-TB) surveillance; the South African Tuberculosis Control Programme is developing initiatives to improve these areas. CONCLUSIONS: Cape Metro's TB surveillance is strong, although it would be strengthened by increasing availability of data reflecting TB-HIV co-infection and MDR-TB. Systems operations could be improved by increasing software flexibility, and increased integration of electronic data across health regions would enhance the capacity and assessment of control efforts.

Abnormal glucose metabolism in non-diabetic patients presenting with an acute stroke: prospective study and systematic review.

BACKGROUND: Non-diabetic patients presenting with an acute stroke often have hyperglycaemia. In most populations it is unknown whether the hyperglycaemia is transient and due to the acute stress response or whether it represents undiagnosed abnormal glucose metabolism. AIM: To evaluate the prevalence and predictors of persistent hyperglycaemia in non-diabetic patients with an acute stroke. DESIGN: Prospective observational study. METHODS: Non-diabetic patients over 40 years old with an acute stroke were enrolled over a 2-year period. On admission patients were evaluated with an HbA(1c) and a 75 g oral glucose tolerance test (OGTT). The OGTT was repeated 3 months later. A meta-analysis was performed to interpret our results in the context of published data. RESULTS: One hundred and seven patients were analysed. On admission 26 (24%) patients had diabetes, 39 (37%) had impaired glucose tolerance and 42 (39%) had normal glucose tolerance. Forty-four (68%) patients with hyperglycaemia on admission were re-investigated at least 3 months after discharge. Of these, 6 (14%) had diabetes, 12 (27%) had impaired glucose tolerance and 26 (59%) had normal glucose tolerance. A 2-h post-load glucose value >or=10 mmol/l predicted persistent hyperglycaemia with 72.2% sensitivity, 65.4% specificity and a positive predictive value and negative predictive value of 59.1 and 77.3%, respectively. A meta-analysis of prevalence data of impaired glucose metabolism in non-diabetic individuals 3 months after having had an acute stroke revealed a combined prevalence of 58% (95% confidence interval 25.4-90.5%). CONCLUSION: In this study hyperglycaemia in the setting of an acute stroke was transient in the majority of patients.

Rheumatic Fever and Rheumatic Heart Disease: Where are we now in South Africa?

South Africa continues to face unacceptably high rates of rheumatic fever (RF) and rheumatic heart disease (RHD); despite readily available and inexpensive preventive measures. However; in the past several years; key players in South Africa's healthcare and political realms in addition to key players from many African nations have come together to acknowledge the persistent health burden attributable to RF/RHD and have agreed to a pledge of action to reduce it.The plan of action is a comprehensive RF/RHD prevention and treatment programme known as ASAP. The ASAP programme targets efforts to raise Awareness; establish surveillance systems; Advocate for increased resources for treatment; and to promote Prevention strategies. South Africa currently has a demonstration site where activities in all of these key areas are currently underway. Efforts in the area of surveillance include a RHD prevalence study that aims to screen 4 000 school-aged children through the use of a mobile echo-surveillance unit. In addition to local efforts; South Africa will join an international initiative to create a global RHD registry that will aid in all aspects of prevention and treatment to further reduce the burden of disease attributable to RF/RHD

Corticosteroids for tuberculous pleurisy.

BACKGROUND: Corticosteroids used in addition to antituberculous therapy have been reported to benefit people with tuberculous pleurisy. However, research findings are inconsistent, raising doubt as to whether such treatment is worthwhile. Concern also exists regarding the potential adverse effects of corticosteroids, especially in HIV-positive people. OBJECTIVES: To evaluate the effects of adding corticosteroids to drug regimens for tuberculous pleural effusion. SEARCH STRATEGY: In May 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 2), MEDLINE, EMBASE, LILACS, Current Controlled Trials, and reference lists of articles. SELECTION CRITERIA: Randomized and quasi-randomized controlled trials comparing any corticosteroid with no treatment, placebo, or other active treatment (both groups should receive the same antituberculous drug regimen) in people diagnosed with tuberculous pleurisy. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial methodological quality and extracted data. Data were analysed using relative risks (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI). The fixed-effect model was applied in the absence of statistically significant heterogeneity. MAIN RESULTS: Six trials with 633 participants met the inclusion criteria; one trial included only HIV-positive people. Compared to control, corticosteroid use was associated with less residual pleural fluid at four weeks (RR 0.76, 95% CI 0.62 to 0.94; 394 participants, 3 trials) and reduced pleural thickening (RR 0.69, 95% CI 0.51 to 0.94; 309 participants, 4 trials). We found no evidence of an effect of corticosteroids on death from any cause (194 participants, 1 trial), respiratory function (191 participants, 2 trials), residual pleural fluid at eight weeks (399 participants, 4 trials), or pleural adhesions (123 participants, 2 trials). Although discontinuation of treatment due to adverse events was more frequent in participants receiving corticosteroids than placebo (RR 2.80, 95% CI 1.12 to 6.98; 586 participants, 6 trials), the effects were generally mild. The risk of Kaposi sarcoma may be increased in HIV-positive people receiving corticosteroids (RR 13.00, 95% CI 0.74 to 227.63; 194 participants, 1 trial). AUTHORS' CONCLUSIONS: There are insufficient data to support evidence-based recommendations regarding the use of adjunctive corticosteroids in people with tuberculous pleurisy. Randomized controlled trials that are sufficiently powered to evaluate the effects of corticosteroids on both morbidity and mortality are needed. The effects of corticosteroids on HIV-related complications, such as Kaposi sarcoma, should be assessed in people co-infected with HIV.

Genotoxicity profiles of common alkyl halides and esters with alkylating activity.

Drug synthesis and/or formulation can generate genotoxic impurities. For instance, strong acid/alcohol interactions during the process of drug salt formation produce alkylating agents such as alkyl halides and alkyl esters of alkyl sulfonic acids. The genotoxicity of a few classic alkylating agents such as methyl and ethyl methanesulfonate have been previously well characterized, whereas the majority of compounds from this class have only been tested in the Salmonella reversion assay. Therefore, the goal of this study was to investigate clastogenicity and DEL recombination profiles of 22 halogenated alkanes and alkylesters of sulfuric and alkane-, aryl-sulfonic acids using a battery of cellular and molecular assays. The in-vitro micronucleus assay in CHO cells was used to measure clastogenicity and the deletion recombination (DEL) assay in S. cerevisiae provided a measure of DNA deletions. We also examined the compounds' reactivity towards 4-(p-nitrobenzyl)pyridine (NBP), a surrogate molecule for biological ring nitrogens. Methylating agents were most potent in all three assays and the alkyl chlorides evaluated in our study were negative in all three assays. Also, a strong correlation was found between the MN, DEL and NBP assays. In summary, this study contributes to a better understanding of the genotoxic properties of common alkyl halides and alkyl esters with alkylating activity and might provide guidance for managing risk of genotoxic process-related impurities of drug substances and products.

Transforming growth factor-beta1 mediates epithelial to mesenchymal transdifferentiation through a RhoA-dependent mechanism.

Transforming growth factor-beta1 (TGF-beta) can be tumor suppressive, but it can also enhance tumor progression by stimulating the complex process of epithelial-to-mesenchymal transdifferentiaion (EMT). The signaling pathway(s) that regulate EMT in response to TGF-beta are not well understood. We demonstrate the acquisition of a fibroblastoid morphology, increased N-cadherin expression, loss of junctional E-cadherin localization, and increased cellular motility as markers for TGF-beta-induced EMT. The expression of a dominant-negative Smad3 or the expression of Smad7 to levels that block growth inhibition and transcriptional responses to TGF-beta do not inhibit mesenchymal differentiation of mammary epithelial cells. In contrast, we show that TGF-beta rapidly activates RhoA in epithelial cells, and that blocking RhoA or its downstream target p160(ROCK), by the expression of dominant-negative mutants, inhibited TGF-beta-mediated EMT. The data suggest that TGF-beta rapidly activates RhoA-dependent signaling pathways to induce stress fiber formation and mesenchymal characteristics.

Interdependent SMAD and JNK signaling in transforming growth factor-beta-mediated transcription.

SMAD and JNK cascades are essential components of the transforming growth factor-beta (TGF-beta) signaling machinery and are implicated in common transcriptional responses. However, the relationship of these pathways to one another downstream of the TGF-beta receptor complex is unknown. We show that JNK is rapidly activated by TGF-beta in a SMAD-independent manner and phosphorylates Smad3 outside its -SSXS motif. Smad3 phosphorylation by JNK facilitates both its activation by the TGF-beta receptor complex and its nuclear accumulation. JNK regulates SMAD- and TGF-beta-mediated transcriptional responses, yet JNK activators only partially stimulate transcriptional responses characteristic of TGF-beta without coincident SMAD pathway activation. These results suggest an interdependent relationship between the JNK and SMAD pathways in TGF-beta-mediated transcription.

RhoB is stabilized by transforming growth factor beta and antagonizes transcriptional activation.

Transforming growth factor beta (TGF-beta) is the prototype for an evolutionarily conserved superfamily of secreted factors implicated in diverse biological phenomena. The pleiotropic responses to TGF-beta are initiated by a heteromeric receptor complex that binds and phosphorylates downstream effectors. Among these, the Smads have been extensively studied. However, less attention has been directed toward alternative downstream effectors and their participation in TGF-beta signal transduction. We show that TGF-beta promotes accumulation of the labile monomeric GTPase RhoB by antagonizing its normal proteolytic destruction, presumably via the 26 S proteasome. RhoB accumulates in its isoprenylated form. Transient overexpression of wild type RhoB but not its dominant negative mutant RhoB-N19 antagonizes TGF-beta-mediated transcriptional activation. These results suggest a novel mechanism of regulation by TGF-beta and implicate RhoB as a negative regulator of TGF-beta signal transduction.

Signal transduction by transforming growth factor-beta: a cooperative paradigm with extensive negative regulation.

Transforming growth factor-beta (TGF-beta) represents an evolutionarily conserved family of secreted factors that mobilize a complex signaling network to control cell fate by regulating proliferation, differentiation, motility, adhesion, and apoptosis. TGF-beta promotes the assembly of a cell surface receptor complex composed of type I (T beta RI) and type II (T beta RII) receptor serine/threonine kinases. In response to TGF-beta binding, T beta RII recruits and activates T beta RI through phosphorylation of the regulatory GS-domain. Activated T beta RI then initiates cytoplasmic signaling pathways to produce cellular responses. SMAD proteins together constitute a unique signaling pathway with key roles in signal transduction by TGF-beta and related factors. Pathway-restricted SMADs are phosphorylated and activated by type I receptors in response to stimulation by ligand. Once activated, pathway-restricted SMADs oligomerize with the common-mediator Smad4 and subsequently translocate to the nucleus. Genetic analysis in Drosophila melanogaster and Caenorhabditis elegans, as well as T beta RII and SMAD mutations in human tumors, emphasizes their importance in TGF-beta signaling. Mount ng evidence indicates that SMADs cooperate with ubiquitous cytoplasmic signaling cascades and nuclear factors to produce the full spectrum of TGF-beta responses. Operating independently, these ubiquitous elements may influence the nature of cellular responses to TGF-beta. Additionally, a variety of regulatory schemes contribute temporal and/or spatial restriction to TGF-beta responses. This report reviews our current understanding of TGF-beta signal transduction and considers the importance of a cooperative signaling paradigm to TGF-beta-mediated biological responses.

Paediatric rhabdomyosarcoma: MyoD1 demonstration in routinely processed tissue sections using wet heat pretreatment (pressure cooking) for antigen retrieval.

AIMS: To investigate wet heat pretreatment (pressure cooking) as a means of antigen retrieval for demonstration of MyoD1 in paraffin wax embedded tissue. METHODS: Routinely processed tissue sections of transmission electron microscope confirmed cases of rhabdomyosarcoma were stained immunohistochemically with the MyoD1 antibody. Antigen retrieval was achieved by wet heat pretreatment of the tissue sections. RESULTS: MyoD1 was stained successfully in all seven cases. The protein was localised to nuclei and cytoplasm depending on the type of tumour cell. CONCLUSIONS: Wet heat pretreatment for antigen retrieval from routinely processed tissue sections permits excellent subsequent immunostaining for MyoD1 in rhabdomyoblasts.

Interaction of the transforming growth factor-beta type I receptor with farnesyl-protein transferase-alpha.

Transforming growth factor-beta 1 (TGF-beta 1) is the prototype of a large family of molecules that regulate a variety of biological processes. The type I (T beta R-I) and type II (T beta R-II) receptors for TGF-beta 1 are transmembrane serine/threonine kinases, forming a heteromeric signaling complex. Recent studies have shown that T beta R-II is a constitutively active kinase and phosphorylates T beta R-I upon ligand binding, suggesting that T beta R-I is the effector subunit of the receptor complex, which transduces signals to intracellular targets. This model has been further confirmed by the identification of constitutively active T beta R-I that mediates TGF-beta 1-specific cellular responses in the absence of ligand and T beta R-II. To investigate signaling by TGF-beta 1, we have sought to isolate proteins that interact with the cytoplasmic region of T beta R-I. One of the proteins identified was the alpha subunit of farnesyl-protein transferase (FT alpha) that modifies a series of peptides including Ras. T beta R-I specifically interacts with FT alpha in the yeast two-hybrid system. Glutathione S-transferase-T beta R-I fusion proteins bind FT alpha translated in vitro. T beta R-I also phosphorylates FT alpha. We further show that the constitutively active T beta R-I interacted with FT alpha very strongly whereas an inactive form of T beta R-I did not. These results suggest that FT alpha may be one of the substrates of the activated T beta R-I kinase.