Decision tree analysis for age estimation in living individuals: integrating cervical and dental radiographic evaluations within a South African population.

Age estimation in living individuals around the age of 18 years is medico-legally important in undocumented migrant cases and in countries like South Africa where many individuals are devoid of identification documents. Establishing whether an individual is younger than 18 years largely influences the legal procedure that should be followed in dealing with an undocumented individual. The aim of this study was to combine dental third molar and anterior inferior apophysis ossification data for purposes of age estimation, by applying a decision tree analysis. A sample comprising of 871 black South African individuals (n = 446 males, 425 = females) with ages ranging between 15 and 24 years was analyzed using panoramic and cephalometric radiographs. Variables related to the left upper and lower third molars and cervical vertebral ring apophysis ossification of C2, C3, and C4 vertebrae analyzed in previous studies were combined in a multifactorial approach. The data were analyzed using a pruned decision tree function for classification. Male and female groups were handled separately as a statistically significant difference was found between the sexes in the original studies. A test sample of 30 individuals was used to determine if this approach could be used with confidence in estimating age of living individuals. The outcomes obtained from the test sample indicated a close correlation between the actual ages (in years and months) and the predicted ages (in years only), demonstrating an average age difference of 0.47 years between the corresponding values. This method showed that the application of decision tree analysis using the combination of third molar and cervical vertebral development is usable and potentially valuable in this application.

Age estimation from anterior cervical vertebral ring apophysis ossification in South Africans.

Age estimation in living individuals around the age of 18 years remains a difficult challenge. In this study, the anterior inferior vertebral ring apophysis development of cervical vertebrae C2, C3, and C4 of 496 white and 478 black South African individuals aged between 15 and 22 years was assessed from cephalometric radiographs. Apophysis development was scored according to a four-stage scoring system. Ancestry and sex differences in apophysis maturation were assessed and likelihood values determined for individuals in each population group being 18 years, based on developmental stages. Regression equations were developed for each ancestry and sex group. The results indicated that the median ages for attainment of stages 0, 1, and 2 were below the 18-year threshold for all ancestry and sex groups. Additionally, WSA males and BSA females attained stage 3 for C2, and WSA females attained stage 3 for C2, C3, and C4, below the 18-year threshold. The presence of stage 0 for black and white males in all three observed vertebrae and stage 1 for black males for C2, C3, and C4, white females for C2 and C3, and white males for C4 indicates an age below 18 years (with a 95% or higher probability). The results indicate that anterior inferior apophysis ossification stages of C2, C3, and C4 can be used as a reliable indicator to determine the likelihood of being 18 years of age at a 95% confidence index level. Apophysis development provides a valuable addition to the methods that can be used to assess age in the adolescent years.

Attenuated brain-derived neurotrophic factor and hypertrophic remodelling: the SABPA study.

Brain-derived neurotrophic factor (BDNF) has been linked to neurological pathologies, but its role in cardiometabolic disturbances is limited. We aimed to assess the association between serum BDNF levels and structural endothelial dysfunction (ED) as determined by cross-sectional wall area (CSWA) and albumin/creatinine ratio (ACR) in black Africans. Ambulatory blood pressure (BP) and ultrasound CSWA values were obtained from 82 males and 90 females. Fasting blood and 8 h overnight urine samples were collected to determine serum BDNF and cardiometabolic risk markers, that is, glycated haemoglobin (HbA1c), lipids, inflammation and ACR. BDNF median split × gender interaction effects for structural ED justified stratification of BDNF into low and high (⩽/>1.37 ng ml(-1)) gender groups. BDNF values (0.86-1.98 ng ml(-1)) were substantially lower than reference ranges (6.97-42.6 ng ml(-1)) in the African gender cohort, independent of age and body mass index. No relationship was revealed between BDNF and renal function and was opposed by an inverse relationship between BDNF and CSWA (r=-0.17; P=0.03) in the African cohort. Linear regression analyses revealed a positive relationship between systolic BP and structural remodelling in the total cohort and low-BDNF gender groups. In the high-BDNF females, HbA1C was associated with structural remodelling. Attenuated or possible downregulated BDNF levels were associated with hypertrophic remodelling, and may be a compensatory mechanism for the higher BP in Africans. In addition, metabolic risk and hypertrophic remodelling in women with high BDNF underpin different underlying mechanisms for impaired neurotrophin homeostasis in men and women.

Estimating age in black South African children.

Forensic dentists are frequently required to determine the age at death of unidentified skeletons, or to age live individuals who have no record/documentation of their chronological age. In order to be of the greatest value, the method used should have the lowest possible standard deviation and be validated for the individual's specific population group. The method most frequently used in Forensic Dentistry for the estimation of age in children, was described by Demirjian et al. The maturity standards determined were based on samples of French Canadian origin and it has been recommended by several authors that correction factors be incorporated when applying this method to different population groups. The current research was carried out on a sample of 838 black South African children. A new model for age estimation in the said population was developed, to accurately determine the chronological age from dental development. A sample of 604 black South African children was used to test the validity of the method described by Demirjian.

Evaluation of waist-to-height ratio to predict 5 year cardiometabolic risk in sub-Saharan African adults.

BACKGROUND AND AIMS: Simple, low-cost central obesity measures may help identify individuals with increased cardiometabolic disease risk, although it is unclear which measures perform best in African adults. We aimed to: 1) cross-sectionally compare the accuracy of existing waist-to-height ratio (WHtR) and waist circumference (WC) thresholds to identify individuals with hypertension, pre-diabetes, or dyslipidaemia; 2) identify optimal WC and WHtR thresholds to detect CVD risk in this African population; and 3) assess which measure best predicts 5-year CVD risk. METHODS AND RESULTS: Black South Africans (577 men, 942 women, aged >30years) were recruited by random household selection from four North West Province communities. Demographic and anthropometric measures were taken. Recommended diagnostic thresholds (WC > 80 cm for women, >94 cm for men; WHtR > 0.5) were evaluated to predict blood pressure, fasting blood glucose, lipids, and glycated haemoglobin measured at baseline and 5 year follow up. Women were significantly more overweight than men at baseline (mean body mass index (BMI) women 27.3 ± 7.4 kg/m(2), men 20.9 ± 4.3 kg/m(2)); median WC women 81.9 cm (interquartile range 61-103), men 74.7 cm (63-87 cm), all P < 0.001). In women, both WC and WHtR significantly predicted all cardiometabolic risk factors after 5 years. In men, even after adjusting WC threshold based on ROC analysis, WHtR better predicted overall 5-year risk. Neither measure predicted hypertension in men. CONCLUSIONS: The WHtR threshold of >0.5 appears to be more consistently supported and may provide a better predictor of future cardiometabolic risk in sub-Saharan Africa.

Attenuated NOx responses and myocardial ischemia, a possible risk for structural vascular disease in African men: the SABPA study.

Chronically elevated blood pressure has been associated with impaired NO-mediated vasodilation and structural vascular disease risk. This study aimed to determine whether significant associations exist regarding NO metabolite (NOx) responses, cardiovascular function and structural vascular disease in a cohort of African and Caucasian men. The study included 81 African and 94 Caucasian male teachers stratified via median splits into low and high NOx ethnic groups. Ambulatory blood pressure, electrocardiogram monitoring and ultrasound carotid intima-media thickness (CIMT) images were obtained. Cardiovascular measurements and fasting blood for NOx responses were measured during rest and on challenging the cardiovascular system with the Stroop colour-word conflict test. African men displayed significantly higher resting NOx as well as higher number of 24 h silent ischemic events than their Caucasian counterparts. Low NOx African men displayed enhanced α-adrenergic and ECG ST segment depression acute mental stress responses as well as 24 h silent ischemic events associated with CIMT (adjusted R(2) = 0.47; ß = 0.25; confidence interval (CI) = 0.13, 0.41). African men demonstrated a vulnerable cardiovascular profile. Novel findings revealed α-adrenergic-driven blood pressure responses and less NO bioavailability during acute stress. The association between myocardial ischemia and CIMT in this group emphasized their risk for future coronary artery disease and cerebrovascular events.

Defensive coping facilitates higher blood pressure and early sub-clinical structural vascular disease via alterations in heart rate variability: the SABPA study.

OBJECTIVES: Defensive coping (AC) responses in urban African males have been associated with vascular responsiveness, partly explaining autonomic nervous system dysfunction. We therefore aimed to assess whether AC responses facilitate higher blood pressure and early sub-clinical structural vascular disease via alterations in frequency- and time-domain heart rate variability (HRV) responses. METHODS: We included 355 African and Caucasian men and women without pre-existing atrial fibrillation, aged 45 ± 9 years. Significant interaction on main effects (coping × ethnicity × gender) for left carotid intima media thickness far wall (L-CIMTf) and cross sectional wall area values necessitated selection of AC responders above mean via the Coping Strategy Indicator. We collected B-mode ultrasound L-CIMTf, ambulatory BP and-HRV data. Overnight fasting blood was obtained. RESULTS: Overall, Africans and AC Africans, mostly men, revealed a poorer lifestyle profile, higher prevalence of hypertensive status, disturbed sympathovagal balance and depressed HRV temporal and geometric patterns compared to the Caucasians (P ≤ 0.05). Moderately depressed non-linear and time-domain HRV (SDNN <100 ms) was prevalent in 28% of Africans compared to 11% of Caucasians. A similar trend was shown for the AC African participants (32%) compared to Caucasians (16%). Only depressed HRV time-domain (SDNN: adj. R(2) = 0.34; ß = -0.24; p = 0.08) and vagal-impaired heart rate responses (RMSSD: adj. R(2) = 0.28; ß = -0.28; p < 0.05) were associated with higher blood pressure and early structural vascular changes in AC African men. CONCLUSION: Defensive coping facilitated autonomic nervous system dysfunction, which was associated with higher blood pressure and sub-clinical structural vascular disease in an African male cohort.

Ticks associated with the three largest wild ruminant species in southern Africa.

The objective of this study was to assess the host status of the three largest southern African wild ruminants, namely giraffes, Giraffa camelopardalis, African buffaloes, Syncerus caffer, and eland, Taurotragus oryx for ixodid ticks. To this end recently acquired unpublished data are added here to already published findings on the tick burdens of these animals, and the total numbers and species of ticks recorded on 12 giraffes, 18 buffaloes and 36 eland are summarized and discussed. Twenty-eight ixodid tick species were recovered. All stages of development of ten species, namely Amblyomma hebraeum, Rhipicephalus (Boophilus) decoloratus, Haemaphysalis silacea, Ixodes pilosus group, Margaropus winthemi, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus glabroscutatum, Rhipicephalus maculatus and Rhipicephalus muehlensi were collected. The adults of 13 species, of which the immature stages use small mammals as hosts, namely Haemaphysalis aciculifer, Hyalomma glabrum, Hyalomma marginatum rufipes, Hyalomma truncatum, Ixodes rubicundus, Rhipicephalus capensis, Rhipicephalus exophthalmos, Rhipicephalus follis, Rhipicephalus gertrudae, Rhipicephalus lounsburyi, Rhipicephalus lunulatus, Rhipicephalus pravus group and Rhipicephalus simus, were also collected.

Prediction of outcome in cancer patients with febrile neutropenia: comparison of the Multinational Association of Supportive Care in Cancer risk-index score with procalcitonin, C-reactive protein, serum amyloid A, and interleukins-1beta, -6, -8 and -10.

The primary objective of the study was to compare the predictive potential of procalcitonin (PCT), C-reactive protein (CRP), serum amyloid A (SAA), and interleukin (IL)-1beta, IL-6, IL-8, and IL-10, with that of the Multinational Association of Supportive Care in Cancer (MASCC) risk-index score in cancer patients on presentation with chemotherapy-induced febrile neutropenia (FN). Seventy-eight consecutive FN episodes in 63 patients were included, and MASCC scores, as well as concentrations of CRP, SAA, PCT, and IL-1beta, IL-6, IL-8 and IL-10, and haematological parameters were determined on presentation, 72 h later and at outcome. Multivariate analysis of data revealed the MASCC score, but none of the laboratory parameters, to be an accurate, independent variable (P < 0.0001) for prediction of resolution with or without complications and death. Of the various laboratory parameters, PCT had the strongest association with the MASCC score (r = -0.51; P < 0.0001). In cancer patients who present with FN, the MASCC risk-index score is a useful predictor of outcome, while measurement of PCT, CRP, SAA, or IL-1beta, IL-6, IL-8 and IL-10, is of limited value.

A survey of free-living ixodid ticks on a commercial game farm in the Thabazimbi District, Limpopo Province, South Africa.

Free-living stages of ticks on a commercial game farm in the Thabazimbi District, Limpopo Province, South Africa, were collected by drag-sampling with flannel strips during the period September 2003 to August 2004. A total of 5 tick species was collected from 4 sites. Boophilus decoloratus was the most abundant species, followed by Amblyomma hebraeum. Seasonal abundance of the ticks was quantified and an optimum time to implement control measures against the ticks is proposed.

The host status of African buffaloes, Syncerus caffer, for Rhipicephalus (Boophilus) decoloratus.

The objective of this study was to assess the host status of African buffaloes, Syncerus caffer, for the one-host tick Rhipicephalus (Boophilus) decoloratus. To this end the R. (B.) decoloratus burdens of ten buffaloes examined in three north-eastern KwaZulu-Natal Province (KZN) nature reserves were compared with those of medium-sized to large antelope species in these reserves and in the southern Kruger National Park (KNP), Mpumalanga Province. The R. (B.) decoloratus burdens of the buffaloes were considerably smaller than those of the antelopes in the KNP, but not those in the KZN reserves. The life-stage structure of the R. (B.) decoloratus populations on the buffaloes, in which larvae predominated, was closer to that of this tick on blue wildebeest, Connochaetes taurinus, a tick-resistant animal, than to that on other antelopes. A single buffalo examined in the KNP was not infested with R. (B.) decoloratus, whereas a giraffe, Giraffa camelopardalis, examined at the same locality and time, harboured a small number of ticks. In a nature reserve in Mpumalanga Province adjacent to the KNP, two immobilized buffaloes, from which only adult ticks were collected, were not infested with R. (B.) decoloratus, whereas greater kudus, Tragelaphus strepsiceros, examined during the same time of year in the KNP harboured large numbers of adult ticks of this species. African buffaloes would thus appear to be resistant to infestation with R. (B.) decoloratus, and this resistance is expressed as the prevention of the majority of tick larvae from developing to nymphs.

Ticks on crested francolins, Francolinus sephaena, and on the vegetation on a farm in Limpopo Province, South Africa.

Ticks were collected at approximately bi-monthly intervals between June 1996 and June 1997 from crested francolins, Francolinus sephaena, and from the vegetation on a mixed cattle and wildlife farm in Limpopo Province, South Africa. The birds were infested with the immature stages of 13 tick species, of which Amblyomma hebraeum, Amblyomma marmoreum and Hyalomma marginatum rufipes were the most numerous and prevalent. Ten ixodid tick species were collected from the vegetation, of which the immature stages of Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) decoloratus and Rhipicephalus evertsi evertsi were the most numerous. No adult ticks were collected from the birds and only two from the vegetation. The restricted home range of crested francolins implies that they could serve as a source of tick infestation only for other animals within the same habitat as the birds.

Ixodid tick infestations of wild birds and mammals on a game ranch in central province, Zambia.

Ticks were collected at irregular intervals from December 1995 to November 1996 from wildlife on Mtendere Game Ranch in the Chisamba District of Central Province, Zambia. Total collections were made from two species of ground-nesting birds and 20 species of small and large mammals. Thirteen species/subspecies of ixodid ticks were recovered. Rhipicephalus appendiculatus was the most abundant, followed by Boophilus decoloratus and Rhipicephalus evertsi evertsi. Small numbers of immature ticks of only a few species were collected from the birds and rodents. The lagomorphs carried large numbers of predominantly immature R. appendiculatus. Most of the ungulates harboured several tick species and had high infestations of R. appendiculatus. The seasonal abundances of Amblyomma variegatum, B. decoloratus, R. appendiculatus and R. evertsi evertsi were determined.

Parasites of domestic and wild animals in South Africa. XXXIII. Ixodid ticks on scrub hares in the north-eastern regions of northern and eastern Transvaal and of KwaZulu-Natal.

Ixodid ticks were collected from scrub hares (Lepus saxatilis) at three localities. Nine tick species were recovered from 24 hares examined at Pafuri, Kruger National Park, Northern Transvaal. The most abundant and prevalent species were Hyalomma truncatum, Rhipicephalus kochi and a Rhipicephalus species (near R. pravus). Twelve tick species were collected from 120 scrub hares examined around Skukuza, Kruger National Park, Eastern Transvaal. The immature stages of Hyalomma truncatum were most abundant and those of Amblyomma hebraeum most prevalent on the hares. No haematozoa were found on blood smears made from these hares. Thirty-four scrub hares on mixed cattle and game farms near Hluhluwe, north-eastern KwaZulu-Natal harboured 12 tick species. The most abundant and prevalent of these were the immature stages of Rhipicephalus muehlensi. Piroplasms, tentatively identified as Babesia leporis, were present on blood smears of eight of these hares. The host status of scrub hares for 18 ixodid tick species or subspecies found in South Africa is tabulated.

Recombinant human erythropoietin in the treatment of cancer-related anaemia.

The aim of this study was to investigate the effects of recombinant human erythropoietin (rh-EPO) in patients with cancer-related anaemia. Thirty-six ambulatory patients who had malignant neoplasms and haemoglobin (Hb) values of < 11 g/dl (Pretoria is 1,310 m above sea level) entered the study. Patients with renal insufficiency or anaemia caused by bleeding or haemolysis, and patients with iron deficiency or megaloblastic anaemia, were not entered in the study. 22 IU/kg rh-EPO was given subcutaneously 3 times/week. The dose was escalated if Hb values did not rise after 4 weeks. All 36 patients were evaluable for toxicity. Side effects ascribed to rh-EPO were pain or discomfort at the site of injection (12 patients), heart palpitations (3 patients), skin rash (2 patients) and hypertension, deep vein thrombosis, and myalgia in 1 patient each. Thirty of the 36 patients who entered the study were evaluable for response. There were 16 females and 14 males among the evaluable patients. Median age was 64.5 years. Response, defined as an increase of Hb of at least 2 g/dl or to 12.5 g/dl, for at least 1 month, was documented in 12 patients. This was accompanied by an improvement in performance status and occurred within 1 month in 5 of the 12 patients who responded. rh-EPO has a limited but measurable therapeutic value for patients with cancer-associated anaemia.

FIVB plus GM-CSF in metastatic colorectal cancer.

The response rate of patients with metastatic colorectal cancer to the 4-drug combination [5-Fluorouracil (5-FU), dacarbazine, vincristine and bis-chloronitrosourea given 5 weekly (FIVB)] was better than the response rate to 5-FU. The dose limiting toxicity of the FIVB was myelosuppression. The present study investigates the effect of FIVB given with GM-CSF so that drug cycles could be given every 4 weeks. Thirty-five ambulatory patients with measurable metastatic colorectal cancer were treated with FIVB plus GM-CSF 4 weekly. All patients were evaluable for toxicity. Among the 163 cycles given only 4 were delayed because of leucopenia and 8 cycles were delayed because of gastrointestinal (GI) toxicity. A 50% dose reduction was given to 10 patients who had Grade 2 and 3 GI toxicity. Four of the 35 patients developed thromboembolic complications, 2 of which were lethal. Two patients were not evaluable for response as they were removed from study early because of toxicity. There were 2 complete responses and 6 partial responses. The median time to treatment failure was 3.8 months and median survival time 9.9 months. The addition of GM-CSF to FIVB decreased the expected leucopenia allowing drug treatment to be given 4 weekly to most patients. GI toxicity was dose limiting. Despite the increased dose intensity that could be delivered (to two thirds of patients), response rates were not definitely increased, no survival benefit was seen and important thromboembolic complications occurred.

Chronological age is a multifactorial prognostic variable in patients with non-Hodgkin's lymphoma.

In order to assess the predictive capacity of chronological age for survival, an analysis of prognostic variables was performed on 277 patients with Non-Hodgkin's Lymphoma, 84 of whom were older than 65 years. All patients were seen at a single institution, and elderly patients, who might otherwise have been excluded from study analysis, were included. Seventeen clinical, radiological and laboratory parameters were evaluated and subjected to univariate and multivariate analyses. Patients older than 65 years had a significantly poorer survival than those younger than 65 years. When the whole group was considered in a multivariate (Cox) model, the factors that independently predicted a longer survival were a good performance status, age less than 65 years and a low grade histological subtype. When patients older and younger than 65 years were analyzed separately the prognostic variables in the elderly were found to be similar to those in younger patients. The predictive capacity of chronological age was found to be influenced by a poor performance status, the presence of concomitant disease, the dose intensity and tolerance of the treatment given, as well as the physiological reserve of the patient. It is concluded that chronological age is a multifactorial prognostic parameter encompassing a number of patient and treatment factors, all of which must be considered when evaluating the capacity of chronological age to predict survival in patients with Non-Hodgkin's Lymphoma.

A phase II study of idarubicin and prednisone in multiple myeloma.

Twenty-one patients with multiple myeloma were treated with idarubicin 45 mg/m2 orally day 1 and prednisone 60 mg/m2 day 1-4 every three weeks. Moderate to severe gastrointestinal and hematopoietic toxicity were observed. Twelve of the twenty-one patients had relapsed on prior treatment. Of these, 2 patients responded. Two patients had primary resistant disease, neither responded. Seven patients had received no prior treatment, three responded. Idarubicin and prednisone have modest activity in refractory myeloma, with short duration of response and severe toxicity.