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1.
Br Dent J ; 231(9): 533, 2021 11.
Article in English | MEDLINE | ID: mdl-34773001
2.
S Afr Med J ; 109(7): 526-534, 2019 Jun 28.
Article in English | MEDLINE | ID: mdl-31266581

ABSTRACT

BACKGROUND: Alcohol use in South Africa (SA) is increasing. The World Health Organization (WHO) states that SA is the third-largest drinking population in Africa, with the highest rate of fetal alcohol syndrome in the world. Internationally, parental drinking during childhood is a risk factor for poor child mental health, behavioural problems and weaker educational outcomes in middle childhood. However, parental alcohol use in Africa is under-researched, and much of the literature on maternal alcohol consumption is restricted to clinical and pregnancy samples. OBJECTIVES: To investigate alcohol use and hazardous drinking (HD) among mothers/primary caregivers of children aged 7 - 11 years in a rural SA cohort. We explored risk factors for drinking and the association between HD and child behaviour/cognition. METHODS: The primary outcome measure was the WHO Alcohol Use Disorder Identification Test (AUDIT) using the standardised cut-off for HD (≥8). Secondary measures were the Patient Health Questionnaire Depression Scale (PHQ-9), Patient Health Questionnaire General Anxiety Disorder Scale (GAD-7), Parenting Stress Index, short form (PSI-36), Child Behaviour Checklist (CBCL, parent reported), Kaufman Developmental Assessment Battery (KABC-II) for child cognition, and Neuropsychological Assessment Battery, 2nd edition, subtests (NEPSY-II) for executive function. We compared characteristics of those drinking/not drinking, using χ2 tests, and modelled outcomes on parenting stress, cognitive outcomes and CBCL scores for children using logistic regression analysis. We grouped mothers/caregivers engaged in HD to examine its effect on parent/child outcomes using t-tests to test for significant differences. RESULTS: Of 1 505 women (1 266 mothers and 239 caregivers) with 1 536 children, 12% reported consuming alcohol and 3% reported HD. Higher maternal/caregiver age (31 - 40 years, adjusted odds ratio (aOR) 0.57 (95% confidence interval (CI) 0.4 - 0.9); >41 years, aOR 0.30 (95% CI 0.2 - 0.5)), education (matriculation, aOR 0.49 (95% CI 0.3 - 0.9); post matriculation, aOR 0.30 (95% CI 0.1 - 0.6)), and a stable relationship with the father (aOR 0.6 (95% CI 0.4 - 1.0)) were associated with no alcohol use. Food insecurity increased the odds of alcohol use (aOR 1.52 (95% CI 1.1 - 2.1)), while parental mental health (parenting stress, anxiety) and child mental health problems were associated with approximately double the odds of consuming alcohol in univariate analysis. Children of HD mothers/caregivers had higher mean scores for psychological problems (CBCL total score: no HD (mean 45.0) v. HD (mean 48.9); p=0.029) and lower cognitive scores (KABC Learning Scale: no HD (mean 14.3) v. HD (mean 12.8); p=0.017). CONCLUSIONS: While HD rates were low, maternal/caregiver alcohol use negatively impacted on parenting and children's behavioural/cognitive outcomes. International evidence suggests that integrated approaches engaging parents and families may be more effective for parent-child outcomes than individual psychiatric or medical care for the parent on their own.


Subject(s)
Alcohol Drinking/psychology , Child Behavior Disorders/epidemiology , Cognition Disorders/epidemiology , Mothers/psychology , Adult , Alcohol Drinking/epidemiology , Anxiety/psychology , Caregivers/psychology , Child , Cohort Studies , Female , Food Supply , HIV Infections/complications , Humans , Male , Mental Health , Neurodevelopmental Disorders/complications , Neuropsychological Tests , Parenting/psychology , Rural Population , South Africa/epidemiology , Stress, Psychological/etiology , Surveys and Questionnaires
4.
J Dev Orig Health Dis ; 9(1): 41-57, 2018 02.
Article in English | MEDLINE | ID: mdl-28899439

ABSTRACT

Longitudinal maternal mental health data are needed from high HIV prevalence settings. The Siyakhula Cohort (SC) is a population-based cohort of HIV-positive and negative mothers (n=1506) with HIV-negative children (n=1536) from rural South Africa. SC includes 767 HIV-negative mothers; 465 HIV-positive in pregnancy; 272 HIV-positive since pregnancy (n=2 missing HIV status). A subgroup (n=890) participated in a non-randomized breastfeeding intervention [Vertical Transmission Study (VTS)]; the remaining (n=616) were resident in the same area and received antenatal care at the time of the VTS, but were not part of the VTS, instead receiving the standard of care Prevention of Mother-to-Child Transmission (PMTCT) Programme. In secondary analysis we investigated the prevalence of, and factors associated with, psychological morbidity amongst mothers who were still the primary caregiver of the child (1265 out of 1506) at follow-up (7-11 years post-birth). We measured maternal depression (Patient Health Questionnaire-9), anxiety (General Anxiety Disorder Scale-7) and parenting stress (Parenting Stress Index-36), using standardized cut-offs and algorithms. In total, 75 (5.9%) mothers met criteria for depression, 37 (2.9%) anxiety and 134 (10.6%) parenting stress. Using complete case logistic regression (n=1206 out of 1265 mothers) as compared to being HIV-negative, testing HIV-positive in pregnancy doubled odds of depression [adjusted odd ratios (aOR)=1.96 [1.0-3.7] P=0.039]. Parenting stress was positively associated with acquisition of HIV after pregnancy (aOR=3.11 [1.9-5.2] P<0.001) and exposure to household crime (aOR=2.02 [1.3-3.2] P=0.003); negatively associated with higher maternal education (aOR=0.29 [0.1-0.8] P=0.014), maternal employment (aOR=0.55 [0.3-0.9] P=0.024). Compared with the standard of care PMTCT, VTS mothers had reduced odds of parenting stress (aOR=0.61 [0.4-0.9] P=0.016). Integrating parental support into mostly bio-medical treatment programmes, during and beyond pregnancy, is important.


Subject(s)
Anxiety/psychology , Depression/psychology , HIV Infections/psychology , Parenting/psychology , Stress, Psychological/psychology , Adult , Anxiety/diagnosis , Anxiety/epidemiology , Child , Depression/diagnosis , Depression/epidemiology , Female , HIV Infections/epidemiology , HIV Infections/transmission , Humans , Infectious Disease Transmission, Vertical/prevention & control , Longitudinal Studies , Male , Mothers/psychology , Patient Health Questionnaire , Pregnancy , Prevalence , Prospective Studies , Rural Population/statistics & numerical data , Schools , South Africa/epidemiology
6.
Phys Med Biol ; 61(16): 6181-202, 2016 08 21.
Article in English | MEDLINE | ID: mdl-27476472

ABSTRACT

A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%-41% for D max esophagus, 31%-68% for D max spinal cord and 7%-32% for V 13 lung.


Subject(s)
Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Four-Dimensional Computed Tomography/methods , Lung Neoplasms/diagnostic imaging , Models, Theoretical , Radiosurgery/methods , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Conformal/methods , Carcinoma, Non-Small-Cell Lung/surgery , Humans , Lung Neoplasms/surgery , Radiotherapy Dosage , Retrospective Studies
7.
J Dev Orig Health Dis ; 7(2): 185-96, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26449271

ABSTRACT

Receiving an education is essential for children living in poverty to fulfil their potential. Success in the early years of schooling is important as children who repeat grade one are particularly at risk for future dropout. We examined early life factors associated with grade repetition through logistic regression and explored reasons for repeating a grade through parent report. In 2012-2014 we re-enrolled children aged 7-11 years in rural KwaZulu-Natal who had been part of an early life intervention. Of the 894 children included, 43.1% had repeated a grade, of which 62.9% were boys. Higher maternal education (aOR 0.44; 95% CI 0.2-0.9) and being further along in the birth order (aOR 0.46; 95% CI 0.3-0.9) reduced the odds of grade repetition. In addition, maternal HIV status had the strongest effect on grade repetition for girls (aOR 2.17; 95% CI 1.3-3.8), whereas for boys, it was a fridge in the household (aOR 0.59; 95% CI 0.4-1.0). Issues with school readiness was the most common reason for repeating a grade according to parental report (126/385, 32.7%), while school disruptions was an important reason among HIV-exposed boys. Further research is needed to elucidate the pathways through which HIV affects girls' educational outcomes and potentially impacts on disrupted schooling for boys. Our results also highlight the importance of preparation for schooling in the early years of life; future research could focus on gaining a better understanding of mechanisms by which to improve early school success, including increased quality of reception year and investigating the protective effect of older siblings.


Subject(s)
Child Development , Educational Status , HIV Infections/physiopathology , Learning Disabilities/epidemiology , Maternal Inheritance , Schools , Adolescent , Case-Control Studies , Child , Child, Preschool , Early Intervention, Educational , Female , HIV/pathogenicity , HIV Infections/virology , Humans , Infant , Infant, Newborn , Male , Prospective Studies , Rural Population , Socioeconomic Factors , South Africa/epidemiology
8.
J Public Health (Oxf) ; 38(1): 24-33, 2016 Mar.
Article in English | MEDLINE | ID: mdl-25742718

ABSTRACT

BACKGROUND: To determine risk factors for overweight/overfatness in children and adolescents from rural KwaZulu-Natal, South Africa. METHODS: Anthropometric data were collected from a cross-sectional sample (n = 1519, ages 7, 11 and 15 years) and linked to demographic information (n = 1310 and n = 1317 in overweight and overfat analyses, respectively). Candidate risk factors for overweight/overfatness were identified and tested for associations with overweight (BMI-for-age >+1SD, WHO reference) and overfatness (>85th centile body fatness, McCarthy reference) as outcomes. Associations were examined using simple tests of proportions (χ(2)/Mann-Whitney U tests) and multivariable logistic regression. RESULTS: Sex was a consistent variable across both analyses; girls at significantly increased risk of overweight and overfatness (overweight: n = 180, 73.9 and 26.1% females and males, respectively (P < 0.0001); overfat: n = 187, 72.7 and 27.3% females and males, respectively (P < 0.0001)). In regression analyses, sex and age (defined by school grade) were consistent variables, with boys at lower risk of overweight (adjusted odds ratio (AOR) 0.40 (confidence interval (CI) -0.28-0.57)) and risk of overweight increasing with age (AOR 0.65 (CI- 0.44-0.96), 0.50 (CI-0.33-0.75) and 1.00 for school grades 1, 5 and 9, respectively). Results were similar for overfatness. CONCLUSIONS: This study suggests that pre-adolescent/adolescent females may be the most appropriate targets of future interventions aimed at preventing obesity in rural South Africa.


Subject(s)
Adiposity , Overweight/etiology , Rural Population/statistics & numerical data , Adolescent , Age Factors , Body Mass Index , Child , Cross-Sectional Studies , Female , Humans , Male , Overweight/epidemiology , Pediatric Obesity/epidemiology , Pediatric Obesity/prevention & control , Risk Factors , Sex Factors , South Africa/epidemiology
9.
Arch Dis Child ; 99(8): 763-6, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24890851

ABSTRACT

OBJECTIVE: To assess the use of mid-upper arm circumference (MUAC) for identification of overweight and overfatness in rural South African children and adolescents. METHODS: Anthropometric data (weight, height, MUAC and % body fat) from a cross-sectional sample of 978 black South African 5-14-year-olds were analysed. Receiver operating characteristic (ROC) curve analysis determined the validity of MUAC as a proxy for determining overweight and overfatness. FINDINGS: Area under the curve (AUC) results were generally high. Boys and girls aged 10-14 years had ROC-AUC for overfatness classed as 'excellent', 0.97 and 0.98 respectively. Cut-points in the MUAC distribution which optimised the ROC-AUC for identification of overfatness and obesity were determined for boys and girls aged 5-9 and 10-14 years, and had high sensitivity and specificity. CONCLUSIONS: MUAC may have potential for clinical and surveillance applications as an accurate yet simple and widely available indicator of overweight and overfatness in children and adolescents in resource-poor settings.


Subject(s)
Anthropometry/methods , Arm/pathology , Overweight/diagnosis , Pediatric Obesity/diagnosis , Adolescent , Area Under Curve , Black People , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Male , ROC Curve , Rural Population , South Africa
10.
Exp Parasitol ; 134(3): 362-7, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23583781

ABSTRACT

Full length cDNA encoding arginine kinases (AK) were cloned from Teladorsagia circumcincta (TcAK) and Haemonchus contortus (HcAK). The TcAK and HcAK cDNA (1080 bp) encoded 360 amino acid proteins. The predicted amino acid sequence showed 99% similarity with each other and 94% with a Caenorhabditis elegans AK. Soluble N-terminal His-tagged AK proteins were expressed in Escherichia coli strain BL21, purified and characterised. All binding sites were completely conserved in both proteins. The recombinant TcAK and HcAK had very similar kinetic properties: K(m) arginine was 0.35 mM, K(m) ATP was 0.8-0.9 mM and the pH optima were pH 7.5. Arginine analogues strongly inhibited recombinant enzyme activities (up to 80%), whilst other amino acids decreased activities by a maximum of 20%. TcAK and HcAK are potential vaccine candidates because of the strong antigenicity of invertebrate phosphagens and kinases and presence in metabolically active parts of the worm.


Subject(s)
Arginine Kinase/genetics , Haemonchus/enzymology , Trichostrongyloidea/enzymology , Amino Acid Sequence , Animals , Arginine/metabolism , Arginine Kinase/antagonists & inhibitors , Arginine Kinase/chemistry , Binding Sites , Cloning, Molecular , DNA, Complementary/genetics , DNA, Helminth/genetics , Electrophoresis, Polyacrylamide Gel , Haemonchus/genetics , Helminth Proteins/chemistry , Helminth Proteins/genetics , Hydrogen-Ion Concentration , Kinetics , Molecular Sequence Data , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Sequence Alignment , Trichostrongyloidea/genetics
11.
Exp Parasitol ; 134(1): 1-6, 2013 May.
Article in English | MEDLINE | ID: mdl-23376286

ABSTRACT

Sarcosine (N-methylglycine) is an intermediate in glycine degradation and can also be synthesised from glycine in mammals. Sarcosine metabolism in Haemonchus contortus and Teladorsagia circumcincta differed from that of mammals in that creatinase activity was present and sarcosine was demethylated only by sarcosine oxidase (SOX) and not by sarcosine dehydrogenase (SDH). The mean SOX activity was 30 nmolmin(-1)mg(-1) protein in homogenates of L3 and adult worms of both parasites and the apparent Km for sarcosine was 1.1 mM. Addition of 2 mM Cd(2+) inhibited activity by 30%. There was no SDH activity with either NAD(+) or NADP(+) as co-factor. Mean creatinase activity in L3 T. circumcincta and adult worms of both species was 31±6 nmolmin(-1)mg(-1) protein, but was undetectable in L3 H. contortus. Activity was inhibited by up to 70% by Cu(2+), Fe(2+), Fe(3+) and Zn(2+). Possessing creatinase would allow host creatine to be incorporated into amino acids by the parasites.


Subject(s)
Haemonchus/metabolism , Sarcosine Oxidase/metabolism , Sarcosine/metabolism , Trichostrongyloidea/metabolism , Ureohydrolases/metabolism , Abomasum/parasitology , Animals , Cadmium/pharmacology , Feces/parasitology , Haemonchiasis/parasitology , Haemonchiasis/veterinary , Haemonchus/enzymology , Hydrogen-Ion Concentration , Kinetics , Larva/enzymology , Larva/metabolism , Male , Sarcosine Dehydrogenase/antagonists & inhibitors , Sarcosine Dehydrogenase/metabolism , Sarcosine Oxidase/antagonists & inhibitors , Sheep , Sheep Diseases/parasitology , Trichostrongyloidea/enzymology , Trichostrongyloidiasis/parasitology , Trichostrongyloidiasis/veterinary , Ureohydrolases/antagonists & inhibitors
12.
Trop Med Int Health ; 18(1): 45-52, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23107420

ABSTRACT

OBJECTIVE: To explore the financial implications of applying the WHO guidelines for the nutritional management of HIV-infected children in a rural South African HIV programme. METHODS: WHO guidelines describe Nutritional Care Plans (NCPs) for three categories of HIV-infected children: NCP-A: growing adequately; NCP-B: weight-for-age z-score (WAZ) ≤-2 but no evidence of severe acute malnutrition (SAM), confirmed weight loss/growth curve flattening, or condition with increased nutritional needs (e.g. tuberculosis); NCP-C: SAM. In resource-constrained settings, children requiring NCP-B or NCP-C usually need supplementation to achieve the additional energy recommendation. We estimated the proportion of children initiating antiretroviral treatment (ART) in the Hlabisa HIV Programme who would have been eligible for supplementation in 2010. The cost of supplying 26-weeks supplementation as a proportion of the cost of supplying ART to the same group was calculated. RESULTS: A total of 251 children aged 6 months to 14 years initiated ART. Eighty-eight required 6-month NCP-B, including 41 with a WAZ ≤-2 (no evidence of SAM) and 47 with a WAZ >-2 with co-existent morbidities including tuberculosis. Additionally, 25 children had SAM and required 10-weeks NCP-C followed by 16-weeks NCP-B. Thus, 113 of 251 (45%) children were eligible for nutritional supplementation at an estimated overall cost of $11 136, using 2010 exchange rates. These costs are an estimated additional 11.6% to that of supplying 26-week ART to the 251 children initiated. CONCLUSIONS: It is essential to address nutritional needs of HIV-infected children to optimise their health outcomes. Nutritional supplementation should be integral to, and budgeted for, in HIV programmes.


Subject(s)
Dietary Supplements/economics , Growth Disorders/diet therapy , HIV Infections/diet therapy , Health Care Costs , Malnutrition/diet therapy , Nutritional Status , Poverty , Adolescent , Anti-HIV Agents/therapeutic use , Body Weight , Child , Child, Preschool , Comorbidity , Eligibility Determination/economics , Growth Disorders/complications , Growth Disorders/economics , HIV Infections/complications , HIV Infections/economics , Humans , Infant , Malnutrition/complications , Malnutrition/economics , Nutritional Requirements , Practice Guidelines as Topic , South Africa , Tuberculosis/complications , Tuberculosis/diet therapy , Tuberculosis/economics , Weight Loss
13.
Psychol Med ; 42(10): 2137-43, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23206379

ABSTRACT

BACKGROUND: The aim of this study was to extend an earlier retrospective cohort study of schizophrenia via a prospective study to a follow-up of 34 years, with an emphasis on describing the life-course of the illness. METHOD: Subjects were 128 first-ever admissions for schizophrenia in 1963 to either of two mental hospital in Alberta, Canada. Follow-up continued until death or 1997. A symptom severity scale, with scores ranging from 0 (no symptoms) to 3 (hospitalized), was used to collect time-series data on each subject and create life-course curves. Indices were constructed to summarize the information in each curve. Information on social functioning was also collected. RESULTS: Results were similar for men and women. The life-course curves showed marked variability of symptom severity across subjects and over time. The average score over the entire period of follow-up for the cohort indicated 'moderate' symptoms, and the change in average score from beginning to end of follow-up demonstrated a slight worsening of symptoms. The measures of social functioning indicated that only about one quarter of the patients had a good to excellent outcome. CONCLUSIONS: The long-term course in schizophrenia is one of varying symptom severity, and for many patients, there is a poor overall outcome.


Subject(s)
Schizophrenia/diagnosis , Social Adjustment , Adult , Alberta , Cohort Studies , Disability Evaluation , Female , Follow-Up Studies , Hospitalization/statistics & numerical data , Hospitals, Psychiatric/statistics & numerical data , Humans , Longitudinal Studies , Male , Middle Aged , Prospective Studies , Psychiatric Status Rating Scales/statistics & numerical data , Retrospective Studies , Schizophrenic Psychology , Severity of Illness Index , Sex Distribution
14.
Exp Parasitol ; 131(1): 101-6, 2012 May.
Article in English | MEDLINE | ID: mdl-22459625

ABSTRACT

Catabolism of lysine through the pipecolate, saccharopine and cadaverine pathways has been investigated in L3 and adult Haemonchus contortus and Teladorsagia circumcincta. Both enzymes of the saccharopine pathway (lysine ketoglutarate reductase (LKR) and saccharopine dehydrogenase (SDH)) were active in L3 and adult worms of both species. All three enzymes which catabolise lysine to α-amino adipic semialdehyde via pipecolate (lysine oxidase (LO), Δ(1)-piperideine-2-carboxylate reductase (Pip2CR) and pipecolate oxidase (PipO)) were present in adult worms, whereas the pathway was incomplete in L3 of both species; Pip2CR activity was not detected in the L3 of either parasite species. In adult worms, the saccharopine pathway would probably be favoured over the pipecolate pathway as the K(m) for lysine was lower for LKR than for LO. Neither lysine dehydrogenase nor lysine decarboxylase activity was detected in the two parasite species. Enzyme activities and substrate affinities were higher for all five enzymes in adult worms than in L3. An unexpected finding was that both LKR and SDH were dual co-factor enzymes and not specific for either NAD(+) or NADP(+), as is the case in other organisms. This novel property of LKR/SDH suggests it could be a good candidate for anthelmintic targeting.


Subject(s)
Haemonchus/metabolism , Lysine/metabolism , Trichostrongyloidea/metabolism , Animals , Cadaverine/metabolism , Haemonchus/enzymology , Hydrogen-Ion Concentration , Kinetics , Larva/enzymology , Larva/metabolism , Lysine/analogs & derivatives , Mixed Function Oxygenases/metabolism , Oxidoreductases Acting on CH-NH Group Donors/metabolism , Pipecolic Acids/metabolism , Saccharopine Dehydrogenases/metabolism , Trichostrongyloidea/enzymology
15.
Tissue Antigens ; 79(2): 114-22, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22107032

ABSTRACT

Optimal methods for using dried blood spots (DBSs) for population genetics-based studies have not been well established. Using DBS stored for 8 years from 21 pregnant South African women, we evaluated three methods of gDNA extraction with and without whole-genome amplification (WGA) to characterize immune-related genes: interleukin-10 (IL-10), killer immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I. We found that the QIAamp DNA mini kit yielded the highest gDNA quality (P< 0.05; Wilcoxon signed rank test) with sufficient yield for subsequent analyses. In contrast, we found that WGA was not reliable for sequence-specific primer polymerase chain reaction (SSP-PCR) analysis of KIR2DL1, KIR2DS1, KIR2DL5 and KIR2DL3 or high-resolution HLA genotyping using a sequence-based approach. We speculate that unequal template amplification by WGA underrepresents gene repertoires determined by sequence-based approaches.


Subject(s)
DNA Fingerprinting/methods , Dried Blood Spot Testing , Histocompatibility Antigens Class I/genetics , Interleukin-10/genetics , Protein Isoforms/genetics , Receptors, KIR/genetics , Adolescent , Adult , DNA/analysis , DNA/genetics , Female , Genetic Variation , Genotype , Histocompatibility Antigens Class I/immunology , Humans , Interleukin-10/immunology , Middle Aged , Polymerase Chain Reaction , Pregnancy , Protein Isoforms/immunology , Receptors, KIR/immunology , Sensitivity and Specificity
16.
Exp Parasitol ; 129(3): 240-6, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21864529

ABSTRACT

A full length cDNA encoding glutamate dehydrogenase was cloned from Teladorsagia circumcincta (TcGDH). The TcGDH cDNA (1614 bp) encoded a 538 amino acid protein. The predicted amino acid sequence showed 96% and 93% similarity with Haemonchus contortus and Caenorhabditis elegans GDH, respectively. A soluble N-terminal 6xHis-tagged GDH protein was expressed in the recombinant Escherichia coli strain BL21 (DE3) pGroESL, purified and characterised. The recombinant TcGDH had similar kinetic properties to those of the enzyme in homogenates of T. circumcincta, including greater activity in the aminating than deaminating reaction. Addition of 1mM ADP and ATP increased activity about 3-fold in the deaminating reaction, but had no effect in the reverse direction. TcGDH was a dual co-factor enzyme that operated both with NAD(+) and NADP(+), GDH activity was greater in the deaminating reaction with NADP(+) as co-factor and more with NADH in the aminating reaction.


Subject(s)
DNA, Helminth/chemistry , Glutamate Dehydrogenase/genetics , Glutamate Dehydrogenase/metabolism , Trichostrongyloidea/enzymology , Amination , Amino Acid Sequence , Ammonia/metabolism , Animals , DNA, Complementary/chemistry , DNA, Complementary/isolation & purification , DNA, Helminth/isolation & purification , Deamination , Gene Expression Regulation, Enzymologic , Glutamate Dehydrogenase/chemistry , Glutamic Acid/metabolism , Hydrogen-Ion Concentration , Kinetics , Molecular Sequence Data , NAD/metabolism , NADP/metabolism , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Alignment , Sheep , Trichostrongyloidea/genetics
17.
Exp Parasitol ; 129(2): 115-9, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21781965

ABSTRACT

A fully functional ornithine-glutamate-proline pathway was detected in L3 and adult Haemonchus contortus and Teladorsagia circumcincta, making the parasites capable of interconversion of these amino acids. Ornithine aminotransferase (OAT) (E.C. 2.6.1.13) was a reversible pyridoxal-5-phosphate (PLP)-dependent enzyme with an optimum pH 8.5. Hydroxylamine completely inhibited OAT activity in both parasites. For all five enzymes, substrate affinity was similar for each species and life cycle stage, the notable exceptions being the nearly 10-fold lower affinity for Δ(1)-pyrroline-5-carboxylate (P5C) of P5C reductase (E.C. 1.5.1.2) in adult T. circumcincta and about half for P5C for L3 H. contortus P5C dehydrogenase (E.C. 1.5.1.12). P5C synthase (E.C. 1.2.1.41) activity was similar with either NADPH or NADH as co-factor. Proline oxidase (E.C. 1.5.99.8) was a co-factor independent enzyme with an optimal pH 8.5. Despite similarities to those in the host, enzymes of this pathway may still be useful as control targets if they differ antigenically, as a supply of proline is necessary for cuticle formation.


Subject(s)
Glutamic Acid/metabolism , Ornithine/metabolism , Proline/metabolism , Sheep Diseases/parasitology , Trichostrongyloidea/enzymology , Trichostrongyloidiasis/veterinary , Abomasum/parasitology , Animals , Feces/parasitology , Haemonchiasis/parasitology , Haemonchiasis/veterinary , Haemonchus/enzymology , Haemonchus/metabolism , Ornithine-Oxo-Acid Transaminase/metabolism , Proline Oxidase/metabolism , Pyrroline Carboxylate Reductases/metabolism , Sheep , Trichostrongyloidea/metabolism , Trichostrongyloidiasis/parasitology
18.
Exp Parasitol ; 127(1): 9-13, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20576519

ABSTRACT

Glutamate synthase (E.C. 1.4.1.14) (GOGAT) activity was not detectable in L3 Haemonchus contortus, but was present in L3 Teladorsagia circumcincta and adult worms of both species. GOGAT activity was inhibited by 80% by azaserine. Activity (nmol min(-1) mg(-1) protein) was 33-59 in adult H. contortus, 51-91 in adult T. circumcincta and 24-41 in L3 T. circumcincta, probably depending on exposure to ammonia, as incubation with 1mM NH(4)Cl doubled GOGAT activity. The pH optimum was 7.5 in both species. Either NAD or NADP acted as co-factor. The mean apparent K(m) for 2-oxoglutarate was 0.7 (0.5-0.9) mM and for glutamine was 1.0 (0.5-1.7) mM for different homogenates. There was no detectable activity in whole parasite homogenates of glutamate decarboxylase (E.C. 4.1.1.15) or succinic semialdehyde dehydrogenase (E.C. 1.2.1.24), the first and third enzymes of the GABA shunt, respectively, suggesting that the GABA shunt is not important in general metabolism in these species.


Subject(s)
Glutamate Synthase/metabolism , Nitrogen/metabolism , Sheep Diseases/parasitology , Trichostrongyloidea/enzymology , Trichostrongyloidiasis/veterinary , Ammonium Chloride/pharmacology , Animals , Azaserine/pharmacology , Brain/enzymology , Enzyme Inhibitors/pharmacology , Glutamate Decarboxylase/metabolism , Glutamate Synthase/antagonists & inhibitors , Glutamate Synthase/drug effects , Haemonchiasis/parasitology , Haemonchiasis/veterinary , Haemonchus/enzymology , Hydrogen-Ion Concentration , Kinetics , Sheep , Succinate-Semialdehyde Dehydrogenase/metabolism , Trichostrongyloidiasis/parasitology
19.
BJOG ; 118(2): 202-18, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21040391

ABSTRACT

Without prevention, a third of HIV-exposed infants acquire HIV in breastfeeding populations before, during, or after delivery through mother-to-child transmission (MTCT). Whereas MTCT is now a sentinel event in resource-rich countries with antiretroviral prophylaxis, caesarean section, and avoidance of breastfeeding, this is not yet the case in resource-poor settings because breastfeeding is crucial to infant survival. Recent advances in postpartum maternal and infant prophylaxis enables safer breastfeeding, and increasing numbers of women accessing treatment and prevention of MTCT services in sub-Saharan Africa is leading to optimism that MTCT could be eliminated here also, as reflected in the UNAIDS target of 2015.


Subject(s)
Developed Countries , Developing Countries , HIV Infections/prevention & control , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Complications, Infectious/prevention & control , Anti-HIV Agents/therapeutic use , Antiretroviral Therapy, Highly Active , Counseling , Female , HIV Infections/diagnosis , HIV Infections/transmission , Humans , Obstetric Labor, Premature/prevention & control , Obstetric Labor, Premature/virology , Practice Guidelines as Topic , Pregnancy , Pregnancy Complications, Infectious/diagnosis , Pregnancy Outcome , Prenatal Care , Prenatal Diagnosis
20.
Exp Parasitol ; 127(2): 506-14, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21055403

ABSTRACT

The ornithine urea cycle, polyamine synthesis, nitric oxide synthesis and metabolism of arginine to putrescine have been investigated in L3 and adult Haemonchus contortus and Teladorsagia circumcincta. Neither parasite had a detectable arginine deiminase/dihydrolase pathway nor a functional ornithine urea cycle. Nitric oxide synthase was present in central and peripheral nerves, but was not detected in whole parasite homogenates. Both arginase (E.C. 3.5.3.1) and agmatinase (E.C. 3.5.3.11) activities were present in both species. Arginase did not require added Mn(2+) and had an optimal pH of 8.5. Polyamine metabolism differed in the two species and from that in mammals. Ornithine decarboxylase (E.C. 4.1.1.17) was present in both parasites, but no arginine decarboxylase (E.C. 4.1.1.19) activity was detected in T. circumcincta. The flexibility of synthesis of putrescine in H. contortus may make this pathway less useful as a target for parasite control than in T. circumcincta, in which only the ornithine decarboxylase pathway was detected.


Subject(s)
Arginine/metabolism , Haemonchus/metabolism , Trichostrongyloidea/metabolism , Abomasum/parasitology , Amidohydrolases/metabolism , Animals , Arginase/metabolism , Argininosuccinate Lyase/metabolism , Argininosuccinate Synthase/metabolism , Carboxy-Lyases/metabolism , Haemonchiasis/parasitology , Haemonchus/enzymology , Histocytochemistry , Hydrolases/metabolism , Larva/enzymology , Larva/metabolism , Nitric Oxide Synthase/metabolism , Ornithine Carbamoyltransferase/metabolism , Ornithine Decarboxylase/metabolism , Sheep , Trichostrongyloidea/enzymology , Trichostrongyloidiasis/parasitology , Ureohydrolases/metabolism
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