Cognitive dysfunction after isolated brain stem insult. An underdiagnosed cause of long term morbidity

Cognitive dysfunction adversely influences long term outcome after cerebral insult, but the potential for brain stem lesions to produce cognitive as well as physical impairments is not widely recognised. This report describes a series of seven consecutive patients referred to a neurological rehabilitation unit with lesions limited to brain stem structures, all of whom were shown to exhibit deficits in at least one domain of cognition. The practical importance of recognising cognitive dysfunction in this group of patients, and the theoretical significance of the disruption of specific cognitive domains by lesions to distributed neural circuits, are discussed.

(E)-2(R)-[1(S)-(Hydroxycarbamoyl)-4-phenyl-3-butenyl]-2'-isobutyl-2'-(methanesulfonyl)-4-methylvalerohydrazide (Ro 32-7315), a selective and orally active inhibitor of tumor necrosis factor-alpha convertase

Tumor necrosis factor-alpha (TNF-alpha), a cytokine secreted by inflammatory cells, has been implicated in several inflammatory disease states. (E)-2(R)-[1(S)-(Hydroxycarbamoyl)-4-phenyl-3-butenyl]-2'-isobutyl-2'-(methanesulfonyl)-4-methylvalerohydrazide (Ro 32-7315), is a potent, orally active inhibitor of the TNF-alpha convertase (TACE), an enzyme responsible for proteolytic cleavage of the membrane bound precursor, pro-TNF-alpha. Ro 32-7315 inhibited a recombinant form of TACE (IC(50) = 5.2 nM) with selectivity over related matrix metalloproteinases. In a cellular assay system, THP-1 cell line, and in human and rat whole blood, Ro 32-7315 significantly reduced lipopolysaccharide (LPS)-induced TNF-alpha release with IC(50) values of 350 +/- 14 nM (n = 5), 2.4 +/- 0.5 microM (n = 5), and 110 +/- 18 nM (n = 5), respectively. Oral administration of Ro 32-7315 to Wistar rats caused a dose-dependent inhibition of LPS-induced release of systemic TNF-alpha with an ED(50) of 25 mg/kg. Treatment (days 0-14) of Allen and Hamburys hooded rats with Ro 32-7315 (2.5, 5, 10, and 20 mg/kg, i.p., twice daily) significantly reduced adjuvant-induced secondary paw swelling (42, 71, 83, and 93%, respectively) as compared with the vehicle group. In the Ro 32-7315-treated group, the reduced paw swelling was associated with improved lesion score and joint mobility. Furthermore, in a placebo-controlled, single-dose study, Ro 32-7315 given orally (450 mg) significantly suppressed ex vivo, LPS-induced TNF-alpha release in the whole-blood samples taken from healthy male and female volunteers (mean inhibition of 42% over a 4-h duration, n = 6). These data collectively support the potential use of such a compound for the oral treatment of inflammatory disorders.

Novel HLA-A locus alleles including A*01012, A*0306, A*0308, A*2616, A*2617, A*3009, A*3206, A*3403, A*3602 and A*6604

This paper describes 10 novel HLA-A alleles that have been characterized by DNA sequencing. Seven alleles, A*0308, A*2616, A*3009, A*3206, A*3403, A*3602 and A*6604 carry motifs observed in other HLA-A alleles, suggesting that gene conversion has created this diversity. The remaining three alleles, A*01012, A*0306 and A*2617, contain polymorphisms not previously found in any "classical" class I allele. All alleles were identified due to unexpected probe hybridization patterns during routine SSOP typing. Exons 2 and 3 of each allele were subsequently characterized by DNA sequencing.

Hypertension in South African adults: results from the Demographic and Health Survey, 1998

OBJECTIVES

To determine the prevalence and treatment status of hypertension in South Africa.

DESIGN

National cross-sectional survey.

SETTING

13 802 randomly selected South Africans, 15 years and older, were visited in their homes in 1998.

METHODS

Trained fieldworkers completed questionnaires on lifestyle and chronic diseases, measured blood pressure with an Omron manometer and recorded chronic drug utilization. Drugs were classified using the Anatomical Therapeutic Chemical index.

RESULTS

The mean systolic blood pressure for men and women was 123 mmHg (SE 0.37) and 119 mmHg (SE 0.36), while the mean diastolic level was 76 mmHg (SE 0.25) and 75 mmHg (SE 0.20), respectively. When using a cut-off point of 140/90 mmHg the hypertension prevalence rate (age-adjusted to the South African Population, Census 1996) was 21% for both genders. Using the current cut-off point (160/95 mmHg) for South Africa, the prevalence rate was 11% for men and 14% for women. For men with hypertension, the level of awareness, taking antihypertensive medication and having controlled blood pressure (< 160/95 mmHg) were 41, 39 and 26% respectively, while for women these rates were 67, 55 and 38% respectively.

CONCLUSIONS

This survey revealed high levels of hypertension in the South African community with inadequate treatment status.

New alleles in the B44 family including B*44022, B*44032, B*4411, B*4420, B*4421, B*4424, and B*8301

Seven new HLA-B locus alleles have been described. B*44022 and B*44032 are silent substitutions altering known alleles. B*4411 carries a unique Bw4-like epitope. B*4420, B*4421, and B*4424 carry new combinations of motifs previously observed in other alleles. B*8301 appears to be the result of the replacement of exon 2 from B*4402 with exon 2 from B*5603.

Changes in plasma progesterone in relation to vitellogenesis and gestation in the viviparous snake Vipera aspis

Viviparity has arisen from oviparity on more than 100 independent occasions in squamate reptiles, providing an unique opportunity to investigate the ways in which endocrine control of gestation length has been modified by natural selection during this major transition in reproductive modes. Intuitively, the evolution of viviparity might be expected to involve an increasingly important role for the steroid hormone progesterone, rather than estradiol. Unfortunately, published data on this topic in snakes are scarce and often contradictory. Females of the viviparous snake Vipera aspis reproduce with a lower than annual frequency, providing the opportunity to examine steroid profiles simultaneously in vitellogenic, pregnant, and postparturient versus nonreproductive females. From 1990 to 1994, more than 500 blood samples were collected from more than 100 females. Progesterone, estradiol-17beta, and several plasma metabolites were assayed by radioimmunoassay and spectrophotometry. In contrast to earlier studies, we found significant differences between plasma progesterone levels in reproducing (10.5 +/- 9.1 ng ml(-1), N = 168) and nonreproducing (5.1 +/- 4.2 ng ml(-1), N = 121) females. Estradiol reached high levels during vitellogenesis (4.8 +/- 4.0 ng ml(-1), N = 16), and progesterone levels increased during gestation (from 3.7 ng ml(-1) before gestation to 18.7 ng ml(-1) at midgestation). However, experimental elevation of plasma progesterone levels with implants (up to 44.4 ng ml(-1)) did not modify plasma metabolite levels or delay parturition.

A man with a prosthetic ear and multiple pulmonary nodules

Basal cell carcinoma is generally regarded as a relatively indolent tumor easily controlled with local therapy. When neglected or inadequately treated this tumor can become locally aggressive and in rare circumstances metastasize. This report documents a case of basal cell carcinoma metastatic to the lung that resulted in rapidly progressive respiratory failure and death.

Application of the new ADA criteria for the diagnosis of diabetes to population studies in sub-Saharan Africa. American diabetes association

AIMS

To examine the implications for epidemiological studies of the American Diabetes Association (ADA) recommendation that the fasting blood glucose at a lowered level becomes the main diagnostic test for diabetes on cross-sectional-based data from sub-Saharan Africa.

METHODS

Data from 11 surveys conducted in rural, peri-urban and urban Cameroon (n = 1804), South Africa (n = 3799) and Tanzania (n = 10013) which measured fasting (ADA criteria) and 2-h blood glucose concentrations during a standard 75 g OGTT (old WHO criteria) were analysed.

RESULTS

The prevalence of diabetes was higher in eight of the 11 surveys when applying the new ADA compared to the old WHO criteria. With the exception of one population (Mara, Tanzania) the absolute difference in prevalence between the two classifications tended to be small (< 2%). There was considerable variation in the categorization of individuals using the ADA and old WHO criteria. The level of agreement between the two ranged from fair to good (Kappa statistic 0.17-0.86). The prevalence of impaired fasting glycaemia (IFG) was lower than that of impaired glucose tolerance (IGT) in 10 of the surveys and the agreement between the two was fair, < or = 0.26 in all the surveys.

CONCLUSIONS

Although the use of the new ADA fasting criteria for prevalence surveys is an attractive and practical option, particularly in Africa, further information is required on the characteristics and prognosis of individuals classified as IFG or diabetic by the fasting criteria, prior to wide adoption of the ADA criteria. Ideally measurement of both fasting and two low glucose concentrations should remain the standard for epidemiological studies.

Rho-kinase inhibitor retards migration and in vivo dissemination of human prostate cancer cells

The Rho-kinase inhibitor, Y-27632, inhibited in vitro chemotactic migration to bone marrow fibroblast conditioned media and metastatic growth in immune-compromised mice of highly invasive human prostatic cancer (PC3) cells. Y-27632 also reduced myosin light chain phosphorylation and markedly altered the morphology of cells that developed numerous processes containing microtubules. A strikingly different, rounded phenotype was induced by an inhibitor of myosin light chain kinase, ML9. The M(110-130) subunit of the myosin phosphatase that is regulated by Rho-kinase was present in PC3 cells that contained significantly more RhoA than the less invasive, LNCaP cells. Y-27632 also inhibited angiogenesis as measured by endothelial cell tube formation on Matrigel. We conclude that invasiveness of human prostate cancer is facilitated by the Rho/Rho-kinase pathway, and exploration of selective Rho-kinase inhibitors for limiting invasive progress of prostate cancer is warranted.

The bisindolylmaleimide protein kinase C inhibitor, Ro 32-2241, reverses multidrug resistance in KB tumour cells

Ro 32-2241 is a bisindolylmaleimide that selectively inhibits protein kinase C (PKC) as compared with other protein kinases. Experiments were carried out to examine its potential as a multidrug resistance-reversing agent. Ro 32-2241 inhibited efflux, and increased accumulation, of [3H]-daunomycin in multidrug-resistant (MDR) KB-8-5 and KB-8-5-11 cells and had no effect on drug-sensitive KB-3-1 cells. Ro 32-2241 completely reversed the doxorubicin resistance of KB-8-5 and KB-8-5-11 cells, showing no effect on the sensitivity of drug-sensitive KB-3-1 cells. The potency of Ro 32-2241 was comparable with that of cyclosporin A and better than that of verapamil, known modulators of multidrug resistance. Ro 32-2241 also completely reversed the taxol resistance of KB-8-5 cells and partially reversed the resistance of KB-8-5-11 cells. Vinblastine resistance was also partially reversed. Mechanistic experiments were carried out to determine whether Ro 32-2241 interacted with P-glycoprotein (Pgp) directly. Increased efflux of [14C]-Ro 32-2241 was seen with the more resistant KB-8-5-11 cells (although the percentage effluxed was very low as compared with [3H]-daunomycin), suggesting that Ro 32-2241 can act as a substrate for Pgp. Direct interaction of Ro 32-2241 with Pgp was confirmed by demonstration that it inhibited binding of [3H]-azidopine to Pgp in KB-8-5-11 membranes. In conclusion, Ro 32-2241, acting directly on Pgp (rather than, or in addition to, an effect on PKC), is effective in reducing or reversing resistance to doxorubicin, taxol and vinblastine in human tumour cells with a clinically relevant degree of MDR. However, results of in vivo experiments conducted to investigate the effects of Ro 32-2241 on resistance to doxorubicin suggest that it may not be possible to achieve sufficiently high levels of Ro 32-2241 in vivo to modulate MDR.

Ecophysiological Studies on Desert Mammals: Insights From Stress Physiology

Ecophysiology is the study of the physiological responses of animals living in their natural environment and can provide information substantially different from that obtained in laboratory situations where animals are constrained by artificial surroundings. Recent work with arid-living mammals in WA has focussed on the measurement of seasonal responses of free-ranging individuals to drought and has involved measurements of rates of turnover of water, together with changes in kidney function and circulating levels of antidiuretic hormone (ADH), the pituitary hormone essential for the conservation of water. Central to these studies has been an attempt to identify periods when animals in the field may be exposed to physiological stress due to a lack of adequate supplies of water, and to document their responses to this. Stress is here defined as "...the physiological resultant of demands that exceed an organism&apos;s regulatory capacities" (Bradshaw, 1986) and is detected through the combination of a significant perturbation of the milieu interieur of the animal, despite the maximum deployment of normal homeostatic responses (e.g. substantial dehydration despite maximal circulating levels of ADH; see Bradshaw, 1992). This approach also raises the possibility of determining the vulnerability to extinction of threatened and endangered species by comparing their actual rates of water turnover in the dry part of the year with allometric predictions. One predicts that species which display a profligate pattern of water usage would be much more susceptible to any environmental changes that might reduce the availability of water.

What is the infant mortality rate in South Africa? The need for improved data

OBJECTIVE

To review recent infant mortality and birth registration data in South Africa and to investigate geographical differences.

OUTCOME MEASURES

Estimates of infant mortality rates, proportion of births not registered, and proportion of births recorded in health services.

METHODS

1. Published infant mortality data for South Africa were collated. Demographic data from national household surveys (1993 and 1994 October Household Surveys and the 1993 Poverty Survey by the Southern African Labour and Development Research Unit (SALDRU) at UCT) were analysed using the indirect method developed by Brass. 2. Birth registration data were analysed and compared with the estimated number of births to identify regions with greater under-registration. The number of births recorded in the health services was analysed by province in order to assess and explore alternatives within health authorities that could complement the existing system.

RESULTS

1. Published estimates of infant mortality for the period from 1990 range from 40 to 71/1,000 births and estimates based on national household surveys conducted in this period from 11 to 81/1,000 births. 2. Completeness of birth registration in the nine provinces ranges from less than 10% in the Eastern Cape, North West and Northern Province to 60% in the Western Cape. An overall improvement from 19% to 60% could be achieved if births recorded through the health services were included in the vital registration system.

CONCLUSIONS

The infant mortality rate in South Africa is not known with any certainty. The extent of completeness of the birth registration system was 19%, which indicates a need for urgent improvement in order to provide key health status indicators. This study indicates that there is some potential for improving the extent of birth registration if it could be facilitated through the health service. However, this alone would not achieve complete registration.

RECOMMENDATIONS

Surveys will have to be relied upon until such time as routinely available statistics are accurate. The October Household Survey conducted annually by the Central Statistical Service as potentially an important source of health status information. It is imperative that either the design of the birth history questionnaire be improved or that it be replaced by a less frequent but more specialised demographic and health survey.