Polycystic ovary syndrome (PCOS) predisposes women to cardiovascular diseases. Blood pressure (BP) responses to the cold pressor test (CPT) predict future cardiovascular risk but have yet to be characterized in PCOS. Therefore, we compared BP responses to the CPT between females with PCOS [ = 10; age: 22 ± 3 yr, body mass index (BMI): 23.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
March 2024
Discharge of postganglionic muscle sympathetic nerve activity (MSNA) is related poorly to blood pressure (BP) in adults. Whether neural measurements beyond the prevailing level of MSNA can account for interindividual differences in BP remains unclear. The current study sought to evaluate the relative contributions of sympathetic-BP transduction and sympathetic baroreflex gain on resting BP in young adults.
View Article and Find Full Text PDFRecent studies have demonstrated that muscle sympathetic nerve activity (MSNA) responses to isometric exercise differs between active and inactive limbs. Whether limb-dependent responses are characteristic of responses to the cold pressor test (CPT) remains to be established. Therefore, we tested the hypothesis that CPT-induced MSNA responses differ between affected and unaffected limbs such that MSNA in the affected lower limb is greater than MSNA responses in the contralateral lower limb and the upper limb.
View Article and Find Full Text PDFPreviously, we demonstrated that integrated muscle sympathetic nerve activity (MSNA) responses to acute chemoreflex stress were augmented during the early follicular (EF) phase of the menstrual cycle relative to both the midluteal (ML) phase and males. These differences were most pronounced in the amplitude component of MSNA, suggesting EF-driven increases in action potential (AP) recruitment in females. Therefore, we tested the hypothesis that neural recruitment, quantified as MSNA AP discharge patterns during acute chemoreflex stress, is potentiated during EF.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
May 2022
Muscle sympathetic nerve activity (MSNA) affects vascular resistance differently in women and men. However, whether this sex difference persists during pronounced increases in MSNA remains unclear. Therefore, the purpose of this study was to examine sex differences in neurovascular transduction during cold pressor test (CPT)-mediated sympathoexcitation.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
September 2020
It has been suggested that sex differences in acute blood pressure fluctuations occur during the periods of time between bursts of muscle sympathetic nerve activity. Therefore, we tested the hypothesis that men experience more dynamic changes in mean arterial pressure (Finometer MIDI) than women during acute sympathoinhibition (i.e.
View Article and Find Full Text PDFPreeclampsia is associated with the development of cardiovascular diseases later in life. To investigate this phenomenon, we compared established markers of cardiovascular dysregulation between previously preeclamptic women (PPE; = 12, 13 ± 6 mo postpartum, 34 ± 6 yr) and women who had previously had an uncomplicated pregnancy [control (CTRL); = 12, 15 ± 4 mo postpartum; 29 ± 3 yr]. We hypothesized that PPE would present with elevated arterial stiffness (assessed as central and peripheral pulse wave velocity) and muscle sympathetic nerve activity (MSNA; microneurography) and blunted baroreflex sensitivity (BRS) relative to CTRL.
View Article and Find Full Text PDFSlow breathing (SLOWB) is recommended for use as an adjuvant treatment for hypertension. However, the extent to which blood pressure (BP) responses to SLOWB differ between men and women are not well-established. Therefore, we tested the hypothesis that an acute bout of SLOWB would induce larger decreases in BP in males than in females, given that males typically have higher resting BP.
View Article and Find Full Text PDFBackground: Neonatal invasive pneumococcal disease (IPD) in developing countries is poorly described. We provide a baseline description of neonatal IPD in South Africa, before implementation of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2009.
Methods: Data from children (age ≤ 2 years) with IPD (pneumococcus identified from a normally sterile specimen) from January 2003 to December 2008 were extracted from a national laboratory-based surveillance database.
Buddleja saligna (family Buddlejaceae) is a medicinal plant endemic to South Africa. Two isomeric pentacyclic triterpenes, oleanolic acid and ursolic acid, were isolated from the leaves of B. saligna using silica gel column chromatography.
View Article and Find Full Text PDFNeonatal candidaemia is a common, deadly and costly hospital-associated disease. To determine the genetic diversity of Candida parapsilosis causing fungaemia in South African neonatal intensive care units (NICUs). From February 2009 through to August 2010, cases of candidaemia were reported through laboratory-based surveillance.
View Article and Find Full Text PDFFrom February 2009 through August 2010, we compared species-level identification of bloodstream Candida isolates and susceptibility to fluconazole, voriconazole, and caspofungin between diagnostic and reference South African laboratories during national surveillance for candidemia. Diagnostic laboratories identified isolates to genus/species level and performed antifungal susceptibility testing, as indicated. At a reference laboratory, viable Candida isolates were identified to species-level using automated systems, biochemical tests, or DNA sequencing; broth dilution susceptibility testing was performed.
View Article and Find Full Text PDFObjectives: To compare Candida species distribution and antifungal susceptibility at South African public- and private-sector hospitals.
Methods: From February 2009 through to August 2010, laboratory-based surveillance for candidaemia was undertaken at 11 public-sector hospitals and >85 private-sector hospitals across South Africa. A case was defined as a patient of any age admitted to a sentinel hospital with isolation of Candida species from blood culture.
Background: Non-tuberculous mycobacteria (NTM) are important environmental pathogens capable of causing a spectrum of infection. The different species exhibit varied geographical prevalence worldwide. Identification of the infecting organism may be helpful in determining the clinical significance of the isolate.
View Article and Find Full Text PDFBackground: Capreomycin is a key antimycobacterial drug in treatment of extensively drug-resistant tuberculosis (XDR-TB). Drug-susceptibility testing (DST) for capreomycin is not routinely performed in newly diagnosed XDR-TB in South Africa. We performed this study to assess the prevalence, clinical significance, and molecular epidemiology of capreomycin resistance in newly diagnosed patients with XDR-TB in KwaZulu-Natal, South Africa.
View Article and Find Full Text PDFWe determined the susceptibility of 102 clinical isolates Cryptococcus neoformans from Durban, South Africa, to amphotericin B, fluconazole, flucytosine, and voriconazole using broth microdilution (BMD) according to the Clinical and Laboratory Standards Institute M27-A3 document and compared these results with Etest and Vitek 2(®). Essential agreement (EA) of Etest and Vitek 2(®) compared to BMD was determined. Low MICs that were below the epidemiological cutoff values of the 4 antifungal agents tested were demonstrated by all isolates.
View Article and Find Full Text PDFSetting: The dual epidemics of HIV-TB including MDR-TB are major contributors to high morbidity and mortality rates in South Africa. Rifampicin (RIF) resistance is regarded as a proxy for MDR-TB. Currently available molecular assays have the advantage of rapidly detecting resistant strains of MTB, but the GeneXpert does not detect isoniazid (INH) resistance and the GenoTypeMTBDRplus(LPA) assay may underestimate resistance to INH.
View Article and Find Full Text PDFBackground: Tuberculous meningitis (TBM) is difficult to diagnose promptly. The utility of the Xpert MTB/RIF test for the diagnosis of TBM remains unclear, and the effect of host- and sample-related factors on test performance is unknown. This study sought to evaluate the sensitivity and specificity of Xpert MTB/RIF for the diagnosis of TBM.
View Article and Find Full Text PDFObjective: HIV-infected patients with treated cryptococcal meningitis are at risk for further neurological deterioration after commencing combination antiretroviral therapy (cART), mostly because of cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS). Identifying predictors of C-IRIS could enable risk stratification.
Design: Prospective, longitudinal cohort study for 24 weeks.
A series of 2-(substituted phenyl/benzyl-amino)-6-(4-chlorophenyl)-5-(methoxycarbonyl)-4-methyl-3,6-dihydropyrimidin-1-ium chlorides 7-13 and 15 was synthesized in their hydrochloride salt form. The title compounds were characterized by FT-IR, NMR ((1)H and (13)C) and elemental analysis. They were evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv, multidrug resistance tuberculosis and extensively drug resistance tuberculosis by agar diffusion method and tested for the cytotoxic action on peripheral blood mononuclear cells by MTT assay.
View Article and Find Full Text PDFWe evaluated some of the regimens recommended for the antimicrobial prophylaxis of infective endocarditis prior to dental extraction in 160 patients. Group A patients served as the control group, group B subjects rinsed their mouths with chlorhexidene, group C subjects took 3 g amoxicillin orally and group D patients took 600 mg clindamycin orally. The proportion of patients who had post-extraction bacteraemia in groups A, B, C and D was 35, 40, 7.
View Article and Find Full Text PDFWe conducted a study to determine the frequency of bacteraemias following dental extraction and common oral procedures, namely tooth brushing and chewing, and the relationship between bacteraemia and oral health in black patients. Positive blood cultures were detected in 29.6% of patients after dental extraction, in 10.
View Article and Find Full Text PDFA series of polycyclic 'cage' derivatives of N-geranyl-1,2 diamines were synthesized and screened for their anti-mycobacterial activity against H(37)Rv, multidrug resistant (MDR) and extensively drug-resistant (XDR) strains of tuberculosis. By substituting the adamantyl skeleton of SQ109 with trishomocubanyl (9), oxa-pentacycloundecyl (14, 16), pentacycloundecyl, PCU, (10, 15) and azapentacycloundecyl (22, 23), the effect of other polycyclic "cage" skeletons could be investigated. Compound 9 (trishomocubanyl moiety) proved to be the most active (MICs: 0.
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