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.

Violence against children: A review of cases at a forensic anthropology unit, Johannesburg, South Africa.

South Africa is experiencing a scourge of violence against women and children, with alarming levels of violence, and as such, juvenile cases are sometimes encountered in a forensic anthropological setting. The aim of this research was to assess the cases of juveniles (under 20 years) presenting at the Human Variation and Identification Research Unit (HVIRU) for a 6-year period (2016-2022), in order to assess patterns and types of cases referred. A total of 19 cases were assessed, of which 10 were 16-20 years old, 3 between the ages of 5 and 15 years and 6 less than 5 years old at the time of death. Of the 14 children with known sex, 12 were female with features suggesting that they fell prey to sexual violence. Many of the individuals were either known (and referred for trauma analysis) or identified following investigation. Of the 19 juveniles, 11 (58 %) had evidence of perimortem trauma (sharp and/or blunt), attesting to the violent nature of their deaths. Two cases had both sharp and blunt force trauma, of which one is a possible case of dismemberment. The remains of two individuals showed signs of perimortem burning, which may or may not be related to the cause of death. Three individuals had signs of antemortem (healed) trauma, which may suggest a longer period of abuse. Five of the individuals showed signs of disease - two had cribra orbitalia, while two others had various porous lesions indicative of chronic disease or malnutrition. One individual had advanced osteomyelitis, suggesting a natural cause of death. Some of these cases had unusual trauma and pathology, highlighting the contribution of forensic anthropologists.

The use of decision tree analysis for improving age estimation standards from the acetabulum.

Accurate, reliable and easy-to-use statistical methods in multifactorial age estimation from the skeleton remains a much-debated issue. In this paper, we explore the use of decision trees in adult age estimation. For this purpose, a dataset from 100 acetabula of South Africans, previously used for age estimation using transition analysis, were used to build a basic decision tree. A test sample of 25 individuals were then employed to assess the newly developed decision tree. Using the decision tree, 20 of the 25 individuals were classified into the correct age group (young, middle or older adults), with the remaining 5 falling within the adjacent age group. The decision tree provided a more accurate outcome as compared to the previous study using transition analysis. Although much research is still needed, this analysis suggests that decision trees may be usable in adult age estimation and may handle the non-linear relationship between chronological and biological age somewhat better than other traditional statistical methods.

Inter-population variation of histomorphometric variables used in the estimation of age-at-death.

Population variation of several microscopic structures used in age-at-death estimation was assessed for three different population samples. The aim of the study was to determine if the need exists for population-specific standards when dealing with individuals of African and European origin. A total sample 223 bone sections from the anterior cortex of the femur (n = 99 black South Africans, n = 94 white South Africans and n = 30 Danish individuals) were analysed using a stereological protocol. Variables assessed included the average number of osteons per grid area (OPD), osteon size and Haversian canal size. ANCOVA was employed for assessment of statistically significant differences. The results indicated that OPD differed significantly between the three groups, but that osteon size was similar for all individuals. Haversian canal size showed unpredictable changes with age and high levels of variation, making it unsuitable to use for age estimation as a single factor. As there are conflicting opinions in the literature on whether to use population-specific equations for the estimation of age-at-death or not, this paper provided additional insight into the use of specific variables and its related variation between groups.

Inflation of 430-parsec bipolar radio bubbles in the Galactic Centre by an energetic event.

The Galactic Centre contains a supermassive black hole with a mass of four million Suns1 within an environment that differs markedly from that of the Galactic disk. Although the black hole is essentially quiescent in the broader context of active galactic nuclei, X-ray observations have provided evidence for energetic outbursts from its surroundings2. Also, although the levels of star formation in the Galactic Centre have been approximately constant over the past few hundred million years, there is evidence of increased short-duration bursts3, strongly influenced by the interaction of the black hole with the enhanced gas density present within the ring-like central molecular zone4 at Galactic longitude |l| < 0.7 degrees and latitude |b| < 0.2 degrees. The inner 200-parsec region is characterized by large amounts of warm molecular gas5, a high cosmic-ray ionization rate6, unusual gas chemistry, enhanced synchrotron emission7,8, and a multitude of radio-emitting magnetized filaments9, the origin of which has not been established. Here we report radio imaging that reveals a bipolar bubble structure, with an overall span of 1 degree by 3 degrees (140 parsecs × 430 parsecs), extending above and below the Galactic plane and apparently associated with the Galactic Centre. The structure is edge-brightened and bounded, with symmetry implying creation by an energetic event in the Galactic Centre. We estimate the age of the bubbles to be a few million years, with a total energy of 7 × 1052 ergs. We postulate that the progenitor event was a major contributor to the increased cosmic-ray density in the Galactic Centre, and is in turn the principal source of the relativistic particles required to power the synchrotron emission of the radio filaments within and in the vicinity of the bubble cavities.

Histological age-at-death estimation in white South Africans using stereology.

Various methods are available for estimating age from skeletal remains, amongst them the use of histomorphometry. It is generally argued that age estimation standards are population specific, but this in itself creates problems as the reference samples used are often not large enough and/or lack substantial representation of all age cohorts. Traditional age methods have been shown to suffer from problems such as age mimicry. This paper aims at establishing histological age-at-death standards for the white South African population by supplementing the available sample (lacking an adequate number of young adults) with another sample of European descent to avoid over-estimation of age in younger individuals caused by age mimicry. Bone microstructures related to the number of osteons and fragments, osteon size and Haversian canal size that change with advancing age were used for the development of regression formulae. A histomorphometric assessment of the anterior cortex of the femur was done using stereology for the estimation of age at death. All sections were analysed using the optical fractionator and nucleator probes. A sample of 94 bone sections (n = 50 male, n = 44 females) of white South African individuals were used. A sample of Danish individuals (n = 14 males, n = 16 females) was combined with the South African sample to create a normal age distribution for the reference sample. Single and multiple regression equations were developed after randomly selecting a hold-out sample (n = 14) for validation. Osteon size (average length, surface area and volume) showed the highest correlation with age, followed by the number of osteons and fragments per grid area. Haversian canal size showed inconsistent changes with advancing age. Using the regression equations, predicted ages were obtained for the 14 individuals. RMSE values ranged between 14 and 17 years, which we deemed acceptable.

Age estimation using bone mineral density in South Africans.

The use of bone mineral density (BMD) to predict age-at-death in skeletal remains provides a usable alternative to other methods because the values obtained are not observer-dependent. The aim of this study was to investigate the usability of BMD to estimate age in South African populations, and to assess inter-population variation and sex-specific differences in BMD values from the proximal end of the femur. In order to estimate age, regression analysis was done for the construction of population dependent formulae. The sample comprised of a total of 123 femora of black and white South Africans. DXA scans were performed using the Hologic Discovery system. Data analysis was done by employing independent-samples t-tests and correlation/regression analyses. The results indicated a statistically significant difference between black and white South Africans. Male groups were also significantly different from one another, but black and white females showed no significant differences. Linear regression analysis revealed a significant correlation between BMD values and age for the white population and the combined sample, but not for the black population. Bootstrapping were employed to confirm validity of the results. In conclusion, this study showed that the use of DXA measurements of the femur for estimating age may be used for the estimation of age-at-death in white South Africans, but more research is needed to better understand the relationship between bone mineral density and age in black South Africans.

The use of stereological methods in the histomorphometric assessment of bone for age-at-death estimation.

Stereological examination of the anterior femur was done for the estimation of age-at-death. The aim of this study was to assess particular bone microstructures that change with advancing age and use these variables to create revised regression formulae applicable to the black population of South Africa. A sample of 99 bone sections (n=60 males and n=39 females) that had previously been analysed using 2D methods, were re-analysed using the optical fractionator and nucleator sampling methods. Single and multiple regression analyses were performed to assess the strength of the relationship between known age and all independent variables. For sex-pooled data, the average number of osteons per grid area (Avg_OPD) showed the highest correlation with age (r=0.528; r2=0.278), followed by average osteon volume (r=-0.383; r2=0.146). The remaining variables reflected a low correlation with age. Pooled, as well as sex-specific single regression formulae were constructed. Multiple regression formulae were constructed for pooled sexes only, as there were no significant difference between males and females overall. Although the employment of stereological methods ensured that the results are accurate and unbiased, the outcome was on par with previously reported SEE's and SD's for this population.

Revisiting historical Khoe-San skeletal remains in European collections: A search for identity through craniometric analysis.

As the identity of a large number of Khoe-San skeletal material in European collections recently came into question during its documentation, a re-evaluation of the remains by employing a non-invasive method such as craniometrics was done to investigate the biological affinity. For this purpose, gene flow and population diversity present within the group, as well as between the study sample (N=63) and other modern and historic population groups from southern, central and east Africa were explored. Available comparative groups included the historic Khoe-San from Riet River (N=31), the Sotho-Tswana from southern Africa (N=61), the Basuku from central Africa (N=66) and the Bahutu (N=53) and Teita (N=24) from east Africa. Ten craniometric variables were selected and used to perform population structure analysis based on model bound quantitative genetics and multiple discriminant function analysis (MDA). Quantitative genetic distances revealed that the Khoe-San sample was closest to the Riet River group. Residual variance analysis performed on two-sample subsets of the Khoe-San group (Cape KS and Various KS) showed a higher level of heterogeneity in the Cape KS than seen in the Khoe-San from various other areas in southern Africa. MDA revealed that Khoe-San intra-sample variance is relatively high, with 44% of the sample (sexes pooled) classified into the Riet River group. The remaining individuals were classified (in decreasing order) into Bahutu (24%), Basuku (24%) and Sotho-Tswana (8%). Although the Khoe-San specimens are closest to the Riet River group, they are clearly not homogenous. Their high level of phenotypic diversity most likely originated from a complex population history involving many group interactions driven by social and political marginalization.

Age estimation from the acetabulum in South African black males.

Anthropologists are constantly seeking to improve methods for age estimation in the human skeleton. A new method was introduced about a decade ago that assesses the morphological changes that take place in the acetabulum as an individual ages. The pelvis is usually well preserved in forensic cases, which makes this method potentially valuable as an adult age indicator. This method employs seven variables, each with its own set of phases. To test the accuracy and reliability of this method, 100 black South African male acetabula from the Pretoria Bone Collection were assessed based on the criteria described in the original study. Box plots and transition curves were constructed to establish whether progression with age was visible and how it could possibly be modelled. Inter-observer reliability was also assessed by making use of Fleiss's Kappa statistic. Five specimens were used as out-of-sample examples for which maximum likelihood (point) estimates were calculated. The results demonstrated that middle and older individuals' age estimates were vastly underestimated. Inter-observer repeatability was poor, which suggested that the classification system most likely needs to be modified. A discussion and recommendation is given for improvement of reliability and repeatability of this method.

Dental health of the late 19th and early 20th century Khoesan.

This paper presents the results of the dental analysis performed on a Khoesan skeletal sample representing the late 19th and early 20th century Cape Colony in southern Africa. Skeletal material from two European collections (Vienna and Paris) was selected to compile a total sample of 116 specimens. Dental pathology frequencies were calculated for caries (28.4%), antemortem tooth loss (37.9%), periapical abscesses (29.3%), periodontal disease (26.7%), calculus (44.0%) and impacted canines (4.3%). Attrition scores indicated that the group under study had an average rate of attrition compared to other southern African populations. Frequency and intensity data were compared to several other samples from both the pre-contact and contact phases by means of chi-squared analysis. The outcome of the study suggested that the group under study was most likely in a state of transition between a diet and lifestyle of hunting-and-gathering and agriculture. Results were also consistent with those of groups from a low socio-economic status.

[A comparison of skilled methods to determine gestational age in pregnancy]. / 'N vergelyking van verskillende metodes om swangerskapstadiums te bepaal.

A group of 208 antenatal women at a primary health care clinic in Bloemfontein was selected for the study. Fundal height was determined by measuring the height of the fundus as well as using the uterine fundus height in relation to weeks method. The above-mentioned methods were compared with a sonar date to determine whether a specific method is more accurate in a specific stage of pregnancy. It seems as if measuring of the height of the fundus is more accurate in the second trimester. In the third trimester of pregnancy a tendency exists for both the uterine fundus height in relation to weeks method and measuring of the height of the fundus to be accurate until the 36th week of pregnancy. After the 36th week of pregnancy the uterine fundus height in relation to weeks method seems to be more accurate.

Amniotomy plus intravenous oxytocin for induction of labour.

BACKGROUND: Induction of labour is a common obstetric intervention. Amniotomy alone for induction of labour is reviewed separately and oxytocin alone for induction of labour is being prepared for inclusion in The Cochrane Library. This review will address the use of the combination of these two methods for induction of labour in the third trimester. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. OBJECTIVES: To determine, from the best available evidence, the efficacy and safety of amniotomy and intravenous oxytocin for third trimester induction of labour. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register and reference lists of articles were searched. Date of last search: May 2001. SELECTION CRITERIA: The criteria for inclusion included the following: (1) clinical trials comparing amniotomy plus intravenous oxytocin used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were done by both reviewers. A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. The initial data extraction was done centrally, and incorporated into a series of primary reviews arranged by methods of induction of labour, following a standardised methodology. The data is to be extracted from the primary reviews into a series of secondary reviews, arranged by category of woman. MAIN RESULTS: Seventeen trials involving 2566 women were included. Amniotomy and intravenous oxytocin were found to result in fewer women being undelivered vaginally at 24 hours than amniotomy alone (relative risk (RR) 0.03, 95% confidence intervals (CI) 0.001-0.49). This finding was based on the results of a single study of 100 women. As regards secondary results amniotomy and intravenous oxytocin resulted in significantly fewer instrumental vaginal deliveries than placebo (RR 0.18, CI 0.05-0.58). Amniotomy and intravenous oxytocin resulted in more postpartum haemorrhage than vaginal prostaglandins (RR 5.5, CI 1.26-24.07). Significantly more women were also dissatisfied with amniotomy and intravenous oxytocin when compared with vaginal prostaglandins, RR 53, CI 3.32-846.51. REVIEWER'S CONCLUSIONS: Data on the effectiveness and safety of amniotomy and intravenous oxytocin are lacking. No recommendations for clinical practice can be made on the basis of this review. Amniotomy and intravenous oxytocin is a combination of two methods of induction of labour and both methods are utilised in clinical practice. If their use is to be continued it is important to compare the effectiveness and safety of these methods, and to define under which clinical circumstances one may be preferable to another.

A formative model for student nurse development and evaluation--Part 1--Developing the model.

Preparing student nurses for the profession is a complex task for nurse educators; especially when dealing with the development of personal and interpersonal skills, qualities and values held in high esteem by the nursing profession and the community they serve. These researchers developed a model for formative evaluation of students by using the principles of inductive and deductive reasoning. This model was implemented in clinical practice situations and evaluated for its usefulness. It seems that the model enhanced the standards of nursing care because it had a positive effect on the behavior of students and they were better motivated; the model also improved interpersonal relationships and communication between practising nurses and students. The fact that students repeatedly use the model as a norm for self evaluation ensures that they are constantly reminded of the standards required of a professional nurse.

Systemic lupus erythematosus with coronary vasculitis and massive myocardial infarction. A case report.

A 32-year-old white woman presented with angina pectoris and an acute myocardial infarction (MI) complicated by congestive cardiac failure. Other symptoms and results of immunological investigation were highly suggestive of systemic lupus erythematosus (SLE). Thallium-201 scintigraphy confirmed an extensive MI, as initially suspected from an ECG. Cardiac catheterization delineated a poorly contracting left ventricle secondary to MI. Selective coronary angiography showed features suspicious of coronary arteritis involving the left anterior descending and left circumflex coronary arteries. Right ventricular endomyocardial biopsy failed to show any 'small-vessel disease', vasculitis or myocarditis. We suggest that the acute MI was caused by coronary arteritis due to SLE. Overview of the literature indicates that coronary arteritis is not as rare a complication of SLE as previously believed; however, acute MI is most unusual.

Disseminated tuberculosis, bone marrow necrosis and lymphoma: a case report.

Tuberculosis often complicates lymphoma, and bone marrow necrosis has been described in disseminated tuberculosis. However, the association of lymphoma, disseminated tuberculosis and bone marrow necrosis is rare. We report a patient with this triple association. After a 3-week influenza-like illness the patient was admitted to hospital semicomatose with pancytopenia and hyponatraemia. During routine examination a bone marrow trephine biopsy revealed diffuse lymphomatous infiltration with scattered necrotic foci. On Ziehl-Neelsen staining these foci exhibited numerous acid-fast bacilli. The patient subsequently died and at autopsy was found to have widely disseminated non-reactive tuberculosis.

GLC determination of paracetamol and d-propoxyphene.

d-Propoxyphene and d-norpropoxyphene were determined in rat plasms, rat brain homogenates and human plasma by means of GLC utilizing extracts obtained by micro-phase extraction of the drugs. Paracetamol was determined in the same samples by GLC separation of the O-butyrate derivative using caffeine as internal standard. The problems associated with the GLC determination of d-propoxyphene and d-norpropoxyphene in biological material are discussed and attention is drawn to the particular advantages of the micro-phase extraction procedure for the quantitative determination of these drugs.

A rapid g.l.c. procedure for the determination of codeine and norcodeine in biological fluids based on micro-phase extraction techniques.

Therapeutic serum concentrations of codeine can be virtually completely extracted and obtained sufficiently concentrated for g.c. measurement without distillation, by acid extraction of the drug from the initial crude organic extracts of alkalinized serum followed by a micro-phase back extraction step. The procedure has simplicity, rapidity and eliminates concentration by distillation and background interference. The method can be readily adapted for the seperate measurements of codeine and norcodeine and it can also be used for similar analysis of other body fluids.

A rapid and comprehensive system for the routine identification of drugs in biological material based on microphase extraction and drug colour profiles.

The separation of basic, acidic and neutral drugs from propanol-2 extracts of serum, urine and tissue homogenates at different pH values using a micro-phase extraction technique is described. Following preliminary screening, the various drug-containing fractions obtained are further examined by two-dimensional thin-layer chromatography. The drugs present are identified with reference to documented standards with the aid of a drug colour profile system and RF values relative to three different reference standards. By means of gas chromatographic analysis of the same extracts, semi-quantitative estimates of the amounts of drugs present, which are sufficiently accurate for clinical emergency purposes, can be made in many instances. The main advantages of the system are "clean" extracts with a minimum of background interference, rapidity (4-6 h for a complete analysis) and systematically documented and visually presented behaviour of drugs after spraying with various chromogenic and fluorogenic reagents, allowing the systematic identification of unknown substances.