Paternity exclusion using 18 genetic systems in 2124 cases in four South African population groups

Using 18 different blood group systems, 2,124 cases of doubtful paternity, unevenly distributed among four different population groups--South African Negroes (Xhosas) 645 (30%); South African Caucasians 264 (13%); Cape Coloureds (non-Malay) 1,156 (54%), and Cape Malays 59 (3%)--were analysed. Tests for red cell antigen, plasma protein, red cell enzyme and HLA polymorphisms were done on all subjects. The overall exclusion rate was 38,23%, i.e. 812 of the 2,124 men were not biological fathers of the children ascribed to them. The capability of the individual systems to exclude a man from specific paternity was also evaluated. The polymorphic HLA system was the most useful and alone--depending on the particular population group--excluded between 93.5% and 97.8% of falsely accused men. The proportion of men excluded also varied between different population groups using the different systems, e.g. the Rhesus system alone excluded 43.9% of South African Caucasian non-fathers and only 14% of the Xhosa non-fathers. This is a reflection of the gene frequencies within a particular population. The analysis showed that the genetic systems tested in this laboratory were extremely efficient in providing evidence in proof of non-paternity.     

Dental education in relation to the needs of the South African community.

The dental needs of a heterogeneous South African community are not being fully met because the majority of the already deficient dentist population is in private practice, mostly in urban areas, where they are rendering services to a small minority of the population who can afford comprehensive dental care. Contrary to public health services in general, public dental services are inadequate in extent and provide a limited range of treatment to some eighty-five per cent of the population. Millions of under-privileged people, particularly in rural areas, are not within range of any professional dental care whatsoever. Organized community preventive programmes and dental health education on a national basis are non-existent. Water fluoridation has not yet become a reality. Realizing the shortcomings in community dental services the Government recently adopted a national dental health policy which is aimed at limiting and preventing dental diseases and also at expanding the public dental service to bring it within reach of all sections of the community. In order to meet the dental needs of the community and also to give momentum to the national dental health policy, the following steps are being taken as far as dental education is concerned: (i) The Department of Health is planning to assist universities to establish departments of community dentistry with the object of promoting extended education in community dentistry at under-graduate and post-graduate level. (ii) Consideration is being given to a scheme whereby dental students will have to do one year compulsory intership. (iii) Additional dental schools are being established to enable more non-White dentists to qualify. (iv) With the extended education in community dentistry it is hoped to draw more dentists into community dental services. (v) Dental therapists are being educated to perform duties such as extractions, simple fillings, prevention and dental health education, under the supervision of dentists, in areas where the shortage of dentists is most crucial.     

Characterization and quantitation of alpha-adrenergic receptor subtypes in rat hypothalamus

The binding of [³H]dihydroergocryptine ([³H]-DHE) to rat hypothalmic membranes was examined. Displacement of [³H]-DHE by 100 nM phentolamine, prazosin and clonidine can be used to assay for total α-, α₁- and α₂-adrenergic receptor sites respectively. The α₁-adrenergic receptor content of the hypothalmus is 4.1 pmoles/g tissue whereas the α₂-level is 6.5 pmoles/g tissue. [³H]-WB 4101 (α₁ selective) and [³H]clonidine (α₂ selective) binding yielded similar levels of 3.2 and 5.8 pmoles/g tissue. It is concluded that [³H]-DHE is a suitable ligand for the assay of α-adrenergic receptor subtypes under the conditions determined in this study.     

A possible role for phosphorylation of the acetylcholine receptor

The acetylcholine receptor (AChR) from Torpedo fuscomaculata can be phosphorylated. This reaction was fully characterised. In addition, the influence of factors with possible modulatory effects on the phosphorylation of this receptor were investigated. In order to suggest the possible role of phosphorylation in neurotransmission, the effects of this reaction on the binding of ligands to the AChR were investigated. It was found that phosphorylation enhanced the binding of the antagonist, alpha-bungarotoxin to the AChR. Due to experimental difficulties the effect on binding of the agonist, acetylcholine, to the receptor, could not be determined. However, a hypothesis is proposed regarding the role of phosphorylation of the AChR in neurotransmission.     

The clock drawing test is a poor screening tool for postoperative delirium and cognitive dysfunction after aortic repair

Background

The Clock Drawing Test (CDT) is a screening tool for dementia that tests a variety of cognitive domains. The CDT takes a maximum of two minutes to complete and might be helpful in identifying postoperative cognitive disorders at the bedside. The objective of this study was to evaluate the accuracy of the CDT in a population at high risk for postoperative cognitive disorders

Methods

In this prospective observational cohort study, patients were recruited who were ≥ 60 yr of age and scheduled for elective open repair of the abdominal aorta. Delirium was assessed using the Confusion Assessment Method (CAM) on postoperative days (POD) 2 and 4 and at discharge. Cognitive function was assessed with neuropsychometric tests before surgery and at discharge. Postoperative cognitive dysfunction (POCD) was determined using the Reliable Change Index. Clock Drawing Tests were administered at all time points. Agreement between the CDT and test for delirium or POCD was assessed with Cohen’s Kappa statistic.

Results

Delirium was noted in 30 of 83 patients (36%; 95% confidence interval [CI] 26 to 46%) during their hospital stay, while POCD was noted in 48 of 78 patients (60%; 95% CI 51 to 72%) at discharge. Agreement between the CDT and CAM was poor at three intervals (Kappa 0.06 to 0.29), as was POCD at discharge (Kappa 0.46). Sensitivity of the CDT was <0.71 for both delirium and POCD at all intervals. False positives and negatives were common.

Conclusion

Agreement between CDT and tests for delirium and POCD was poor; sensitivity was inadequate for a screening test. (ClinicalTrials.gov number, NCT00911677).     

A prospective cohort study evaluating associations among delirium, postoperative cognitive dysfunction, and apolipoprotein E genotype following open aortic repair

Background

Patients undergoing major vascular surgery are at high risk of postoperative delirium and postoperative cognitive dysfunction (POCD). Apolipoprotein E (APOE) is involved in central acetylcholine synthesis, and patients bearing the ε4 genotype (APOE-ε4) are at increased risk of both vascular dementia and peripheral vascular disease. The purpose of this study was to evaluate the associations among delirium, POCD, and APOE-ε4 in patients undergoing open aortic repair.

Methods

Following Research Ethics Board approval and written informed consent, we recruited a cohort of patients ≥ 60 yr of age undergoing open aortic repair. Apolipoprotein E genotyping and a battery of nine neuropsychometric (NP) tests were performed prior to surgery. Delirium was assessed on postoperative days two, four, and discharge using the Confusion Assessment Method. Neuropsychometric testing was repeated at discharge and again three months following surgery. A group of non-surgical patients was used to adjust NP scores using reliable change index methodology. Logistic regression was used to evaluate independent predictors of both delirium and POCD.

Results

Eighty-eight patients underwent surgery, 78 completed NP testing on discharge, and sixty-nine completed NP testing at three months. Delirium was noted in 36% of patients after surgery, while POCD was noted in 62% at discharge and 6% at three months. Delirium predicted POCD at discharge (odds ratio 2.86; 95% confidence intervals 0.99 to 8.27) but not at three months. Apolipoprotein E-ε4 genotype was not associated with either delirium or POCD following adjustment for covariates.

Conclusion

Both delirium and POCD are common following open aortic repair; however, the APOE genotype did not predict either condition. This trial has been registered with ClinicalTrials.gov (NCT00911677).     

HLA frequencies in Black Zimbabweans

One-hundred-and-nineteen normal Black Zimbabweans were typed for HLA antigens. We found a close similarity between the HLA antigen frequencies in Zimbabweans and Black South Africans (Xhosa), another Bantu-speaking group. The only significant differences noted were for HLA-Aw36, -Bw53, -Cw6, -DR4 and -DQw3 (p less than 0.01). The most common HLA haplotypes in significant positive linkage disequilibrium in the two groups were different. The differences that were noted may be due to gene flow from the San to the Black South Africans, since it is thought that the Zimbabweans had little if any contact with the San.