The clinical utility of PET/CT scan and tissue biopsy in the management and follow-up of paediatric Hodgkin lymphoma in South Africa

BACKGROUND

In low- to middle-income countries (LMICs) like South Africa, there is a need to understand the clinical practices surrounding diagnosis and surveillance of paediatric Hodgkin lymphoma (HL) to reduce the burden on health systems. Understanding the clinical utility of PET/CT scans may decrease repeated tissue biopsies during disease surveillance.

METHODS

This is a retrospective cohort study of patients aged less than 18 years treated for HL at Chris Hani Baragwanath Academic Hospital from 1 January 2009 to 31 December 2018.

RESULTS

Fifty-four patients were included in the study; male-to-female ratio was 5:1 with a mean age of 9 years. Seventy per cent of patients (n = 38) received a PET/CT and tissue biopsy during their initial diagnostic workup, whereas 20.4% (n = 11) of patients received a PET/CT and tissue biopsy during surveillance. Tissue biopsy and PET/CT showed slight agreement (κ = 0.14) in diagnosing relapsed disease during surveillance. The false negative rate for tissue biopsy during surveillance was 42.9%. Surveillance PET/CT showed a positive predictive value (PPV) of 66.7% and negative predictive value (NPV) of 100% when compared to tissue biopsy.

CONCLUSION

This study is the first cohort to explore the clinical utility of PET/CT scans and tissue biopsies in a lowresourced setting. Our findings showed slight agreement between the modalities in diagnosing relapsed disease during surveillance. A portion of this discordance can be attributed to false negative tissue biopsy results. While the sample is limited, our findings are consistent with the high NPV of PET/CT scans of > 95% as is reported in the literature.

Pelvic and acetabular fracture care in England: current workload and future directions

INTRODUCTION

Fractures of the pelvis and acetabulum (PAFs) are challenging injuries, requiring specialist surgical input. Since implementation of the major trauma network in England in 2012, little has been published regarding the available services, workforce organisation and burden of PAF workload. The aim of this study was to assess the recent trends in volume of PAF workload, evaluate the provision of specialist care, and identify variation in available resources, staffing and training opportunity.

METHODS

Data on PAF volume, operative caseload, route of admission and time to surgery were requested from the Trauma Audit and Research Network. In order to evaluate current workforce provision and services, an online survey was distributed to individuals known to provide PAF care at each of the 22 major trauma centres (MTCs).

RESULTS

From 2013 to 2019, 23,823 patients with PAF were admitted to MTCs in England, of whom 12,480 (52%) underwent operative intervention. On average, there are 3,971 MTC PAF admissions and 2,080 operative fixations each year. There has been an increase in admissions and cases treated operatively since 2013. Three-quarters (78%) of patients present directly to the MTC while 22% are referred from regional trauma units. Annually, there are on average 37 operatively managed PAF injuries per million population. Notwithstanding regional differences in case volume, the average number of annual PAF operative cases per surgeon in England is 30. There is significant variation in frequency of surgeon availability. There is also variation in rota organisation regarding consistent specialist surgeon availability.

CONCLUSIONS

This article describes the provision of PAF services since the reorganisation of trauma services in England. Future service development should take into account the current distribution of activity, future trends for increased volume and casemix, and the need for a PAF registry.

Cost-effectiveness of the SQ HDM SLIT-tablet for the treatment of allergic asthma in three Eastern European Countries

Summary

Background.The SQ® house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet (ACARIZAX®, ALK-Abelló A/S, Hørsholm, Denmark) is an allergy immunotherapy tablet for people with allergic respiratory disease. This analysis aims to assess the cost-effectiveness of the SQ HDM SLIT-tablet from the perspective of three Eastern European countries: Czech Republic, Poland and Slovakia. Methods.A cost-utility model per country was developed, which compared the SQ HDM SLIT-tablet as add-on to pharmacotherapy with pharmacotherapy alone in patients with HDM allergic asthma (AA) over a five year time horizon. The effectiveness of the two interventions was based on the results from a large-scale randomised controlled trial. In the models, annual costs and quality-adjusted life year (QALY) scores from the trial were extrapolated over a five year period, and the incremental cost-effectiveness ratios (ICERs) were estimated. One-way deterministic sensitivity and scenario analyses were undertaken. Results.The SQ HDM SLIT-tablet is cost-effective in all three markets over the five year time horizon (ICERs of less than € 10,000 per additional QALY). Treatment with the SQ HDM SLIT-tablet improves patient outcomes, with QALY gains of 0.35, versus pharmacotherapy only. In all three countries, the SQ HDM SLIT-tablet also incurs increased costs compared to pharma-cotherapy treatment only. The sensitivity analysis identified utility values from the clinical trial as the main driver of the model results. Conclusion.The SQ HDM SLIT-tablet is a cost-effective treatment option for people with HDM AA in three different health care settings in Eastern Europe.

Meticillin-resistant Staphylococcus aureus in the intensive care unit: its effect on outcome and risk factors for acquisition

BACKGROUND

Meticillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infection in the intensive care unit (ICU). A perception exists that ICU-acquired MRSA is associated with poor outcomes, although there are few data to support this.

AIM

To determine the effect of acquiring MRSA in the ICU on 180-day mortality, and to identify risk factors associated with acquisition.

METHODS

Data were collected prospectively from 2007 to 2013. Patients who remained MRSA negative throughout their ICU admission were matched with patients who acquired MRSA in terms of age, Acute Physiology and Chronic Health Evaluation II score, length of ICU stay and surgical/non-surgical status.

FINDINGS

In total, 2405 patients were included in the analysis. Patients who acquired MRSA in the ICU had significantly longer ICU stays than patients who were admitted with MRSA and patients who remained MRSA negative throughout their ICU stay (P < 0.001 for both). There were no significant differences in 180-day mortality between the groups (P = 0.238). A confirmed non-MRSA infection within 48 h of ICU admission was associated with increased risk of MRSA acquisition (adjusted odds ratio 2.57, P = 0.005), and receipt of antimicrobial therapy within 48 h of ICU admission was associated with reduced risk of MRSA acquisition (adjusted odds ratio 0.38, P = 0.014).

CONCLUSION

MRSA acquisition does not contribute towards mortality in critically ill patients. This raises questions regarding the cost-effectiveness of focusing infection prevention measures on the control of MRSA in ICUs. The low acquisition rate and lack of risk factors identified for MRSA in the study cohort indicate that efforts should be directed towards continual improvement of standard infection control procedures for all patients.

Minimizing brain shift during functional neurosurgical procedures - a simple burr hole technique that can decrease CSF loss and intracranial air

BACKGROUND

Exact stereotactic placement of deep brain stimulation electrodes during functional stereotactic neurosurgical procedures can be impeded by intraoperative brain shift. Brain shift has been shown to correlate with the amount of intracranial (subdural) air detected on early postoperative imaging studies. We report a simple burr hole technique that reduces the loss of cerebrospinal fluid (CSF) and has the potential to significantly reduce the amount of postoperative intracranial air.

MATERIAL AND METHODS

A total of 16 patients were studied with half (group 2) receiving the burr hole technique designed to seal the CSF space and thereby reducing CSF loss. The other 8 patients (group 1) received the standard burr hole technique. The 2 groups were of similar age, gender, diagnosis (Parkinson's disease, n=14; cervical dystonia n=2), and surgical targets. All patients received bilateral electrodes either in the subthalamic nucleus (STN, n=14) or in the globus pallidum internus (GPi, n=2) avoiding transventricular trajectories. Early postoperative 3-dimensional computed tomography (3D CT) was used to check for possible bleeding, DBS lead location, and the amount of intracranial air. Intracranial air was assessed manually in a volumetric slice-by-slice approach in the individual postoperative CT and the groups compared by t-test.

RESULTS

Group 2 showed significantly lower postoperative intracranial air volumes (4.86 ± 4.35cc) as compared to group 1 (27.59 ± 17.80 cc, p=0.0083*). The duration of surgery, however, was significantly longer for group 1 (435 ± 56.05 min) as compared to group 2 (316 ± 34.79 min,p=0.00015*).The time span between the conclusion of the operation and postoperative 3DCT was similar for both groups.

CONCLUSION

This new and simple burr hole technique was associated with a significant reduction in postoperative intracranial air. Reduction of intracranial air will ultimately reduce brain shift. That total operation time does not influence intracranial air is discussed as well as the limitations of this pilot series. In the authors' opinion, this straightforward and cost-effective technique has the potential to reduce brain shift and to increase DBS placement accuracy during functional stereotactic neurosurgical procedures performed in the seated or half-sitting position. A larger more standardized patient series is necessary to substantiate the findings.

Integration of concurrent trauma registry and performance improvement programs

Health information management systems have had a tremendous impact on the delivery of healthcare. The implementation of an integrated, concurrent trauma registry and performance improvement system has had a remarkable impact on the University of Pennsylvania's trauma program. Having both the registry and performance improvement programs concurrent and integrated has allowed better utilization of staff and has produced more accurate, relevant and timely data.

Principles and problems underlying testing the effectiveness of blast protective footwear

Anti-personnel landmines are a continuing threat to soldiers and civilians working overseas in post conflict situations. Several groups of governmental and commercial scientists are currently designing and/or testing footwear to protect the lower leg from the effects of close proximity blast. The general principles surrounding testing of protective footwear are examined together with an assessment of the known progress to date and the strengths and weaknesses of the designs produced.

Underappreciation of sleep disorders as a cause of motor vehicle crashes

Despite an increased risk of motor vehicle crashes (MVC) in patients with obstructive sleep apnea (OSA), we hypothesized that OSA was not considered in drivers admitted to trauma centers after an injury-producing MVC. A retrospective study on drivers involved in MVCs admitted to a level 1 trauma center was performed, with crash cause determined and the frequency of sleep studies recorded. A questionnaire was also mailed to 240 trauma centers seeking information on evaluation of patients with unexplained causes for MVCs, including screening for OSA. There were 122 drivers of MVCs admitted to our hospital, 60/122 (49%) had unexplained crashes and no sleep studies were performed. There were 70 survey respondents (30% return rate), 35/70 (50%) centers routinely screened for syncope after unexplained MVC, however, no center screened for OSA. US trauma centers do not screen for sleep disorders despite the associated increased crash risk and the high prevalence of crashes that can not be explained by other causes. We believe this reflects a lack of awareness of sleep disorders by health care professionals caring for trauma victims and education is of utmost importance.

A phenoxyl radical complex of copper(II)

A new N,O-bidentate pro-ligand (HL), [ML2] (M = Cu, Zn) and [CuL2][BF4] have been synthesised; [CuL2].4DMF and [CuL2][BF4].2CH2Cl2 have been crystallographically and spectroscopically characterised; these data indicate that [CuL2]+ cations are constituted as [Cu2+(L.)(L-)]+ and involve the phenoxyl radical L..

Electronic spectral studies of molybdenyl complexes. 2. MCD spectroscopy of [MoOS4]- centers

Magnetic circular dichroism (MCD) and absorption spectroscopies have been used to probe the electronic structure of [PPh4][MoO(p-SC6H4X)4] (X = H, Cl, OMe) and [PPh4][MoO(edt)2] complexes (edt = ethane-1,2-dithiolate). The results of density functional calculations (DFT) on [MoO(SMe)4]- and [MoO(edt)2]- model complexes were used to provide a framework for the interpretation of the spectra. Our analysis shows that the lowest energy transitions in [MoVOS4] chromophores (S4 = sulfur donor ligand) result from S-->Mo charge transfer transitions from S valence orbitals that lie close to the ligand field manifold. The energies of these transitions are strongly dependent on the orientation of the S lone-pair orbitals with respect to the Mo atom that is determined by the geometry of the ligand backbone. Thus, the lowest energy transition in the MCD spectrum of [PPh4][MoO(p-SC6H4X)4] (X = H) occurs at 14,800 cm-1, while that in [PPh4][MoO(edt)2] occurs at 11,900 cm-1. The identification of three bands in the absorption spectrum of [PPh4][MoO(edt)2] arising from LMCT from S pseudo-sigma combinations to the singly occupied Mo 4d orbital in the xy plane suggests that there is considerable covalency in the ground-state electronic structures of [MoOS4] complexes. DFT calculations on [MoO(SMe)4]- reveal that the singly occupied HOMO is 53% Mo 4dxy and 35% S p for the equilibrium C4 geometry. For [MoO(edt)2]- the steric constraints imposed by the edt ligands result in the S pi orbitals being of similar energy to the Mo 4d manifold. Significant S pseudo-sigma and pi donation may also weaken the Mo identical to O bond in [MoOS4] centers, a requirement for facile active site regeneration in the catalytic cycle of the DMSO reductases. The strong dependence of the energies of the bands in the absorption and MCD spectra of [PPh4][MoO(p-SC6H4X)4] (X = H, Cl, OMe) and [PPh4][MoO(edt)2] on the ligand geometry suggests that the structural features of the active sites of the DMSO reductases may result in an electronic structure that is optimized for facile oxygen atom transfer.

Biomechanics of ankle and hindfoot injuries in dynamic axial loading

Twenty-three Post Mortem Human Surrogate (PMHS) limbs were impacted using a test set up that was developed to simulate the loading conditions seen in a frontal collision. Articulation studies were performed on each limb prior to impact. Failure occurred at impact loads of 5.7+/-1.9 kN (resultant tibial failure load 6.4+/-1.9 kN) and the following injuries were generated: 9 intra-articular calcaneal fractures; 1 talar neck and 2 talar body fracture; 3 intra-articular distal tibial (pilon) fractures; 2 malleolar fractures; 3 soft tissue injuries and 3 had no detectable injury. The impact test conditions were replicated with a Hybrid III leg in a first attempt at developing injury risk functions for the dummy. This study has demonstrated the significance of preload through muscle tension and the intrinsic properties of PMHS specimens in the generation of severe ankle and hindfoot injury.

An MCD spectroscopic study of the molybdenum active site in sulfite oxidase: insight into the role of coordinated cysteine

Temperature-dependent magnetic circular dichroism (MCD) spectroscopy has been used for the first time to probe the electronic structure of the Mo active site in sulfite oxidase (SO). The enzyme was poised in the catalytically relevant [Mo(V):Fe(II)] state by anaerobic reduction of the enzyme with the natural substrate, sulfite, in the absence of the physiological oxidant cytochrome c. The [Mo(V):Fe(II)] state is of particular importance, as it is proposed to be a catalytic intermediate in the oxidative half reaction, where SO is reoxidized to the resting [Mo(VI):Fe(III)] state by two sequential one-electron transfers to cytochrome c. The MCD spectrum of the enzyme shows no charge transfer transitions below approximately 17000 cm(-1). This has been interpreted to result from (1) a severe reduction in ene-1,2-dithiolate sulfur in-plane and out-of-plane p orbital mixing, (2) a decrease in the dithiolate sulfur out-of-plane p-Mo d(xy) orbital overlap, and (3) an orthogonal orientation between the vertical cysteine sulfur p (perpendicular to the Mo-Scys sigma-bond) and Mo d(xy) orbitals. The spectroscopically determined cysteine sulfur p-Mo d(xy) bonding scheme in the [Mo(V):Fe(II)] state is consistent with the crystallographically determined O-Mo-Scys-C dihedral angle of approximately 90 degrees and precludes a covalent interaction between the vertical cysteine sulfur p orbital and Mo d(xy), effectively decoupling the cysteine from an effective through-bond electron transfer pathway. We have tentatively assigned a 22250 cm(-1) positive C-term feature in the MCD as the cysteine S(sigma)-->Mo d(xy) charge transfer that becomes allowed by a combination of configuration interaction and low-symmetry; however, the orbital overlap is anticipated to be quite small due to the near orthogonality of these orbitals. Therefore, we propose that the primary role of the coordinated cysteine is to decrease the effective nuclear charge on Mo by charge donation to the metal, statically poising the active site at more negative reduction potentials during electron transfer (ET) regeneration. Finally, the results of this study are consistent with the pyranopterin ene-1,2-dithiolate acting to couple the Mo site into efficient superexchange pathways for ET regeneration following oxygen atom transfer to the substrate.

Effects of atorvastatin treatment on the oxidatively modified low density lipoprotein in hyperlipidemic patients

Atorvastatin is an established HMG-CoA reductase inhibitor which effectively reduces the plasma low density lipoprotein (LDL)-cholesterol level in hyperlipidemic patients. The present study was designed to investigate whether atorvastatin treatment can modify the biochemical content of oxidized LDL in hyperlipidemic patients and the ability of oxidized LDL to impair the endothelium-dependent relaxation of blood vessels. With atorvastatin (10 mg/day) treatment for 4 weeks in 19 type IIa hyperlipidemic patients, total cholesterol level was lowered by 23%, LDL-cholesterol was lowered by 32% and triacylglycerol was lowered by 19% as compared with dietary therapy alone. High density lipoprotein levels increased by approximately 9%. The ability of oxidized LDL from hyperlipidemic patients after atorvastatin treatment to impair the endothelium-dependent relaxation was significantly reduced as compared with dietary intervention alone. Analysis of the biochemical contents of oxidized LDL from this group revealed that there was an 11% reduction in lysophosphatidylcholine (LPC) as compared with the group that received only dietary counseling. A decrease in the C16:0 moiety with a corresponding increase in the C18:0 moiety of LPC in the oxidized LDL was also observed in the atorvastatin treated group. We propose that the observed reduction and the change in composition of acyl groups in LPC in the oxidized LDL of the atorvastatin-treated group results from a combination of the continued dietary treatment as well as drug therapy. In view of an observation that both C16:0 and C18:0 LPC species are equally potent in the impairment of endothelium-dependent relaxation of the aortic rings, we feel that the reduced level of LPC in the oxidized LDL produced by atorvastatin treatment is partially responsible for the improvement in endothelium control of vascular tone.

Two-dimensional gel analysis of haemolymph proteins from Plasmodium-melanizing and -non-melanizing strains of Anopheles gambiae

Haemolymph polypeptides from Plasmodium-refractory and -susceptible mosquitoes were compared by one- and two-dimensional gel electrophoresis. The refractory strain of Anopheles gambiae kills malaria parasites by a humoral melanization mechanism whereas the parasites develop normally in susceptible mosquitoes. The two strains respond in a similar manner to carboxy-methyl-Sephadex beads that have been injected into the thoracic haemocoel, i.e. beads are strongly melanized in refractory but not susceptible mosquitoes. Protein profiles were compared between strains following cold shock (naïve control), saline injection and Sephadex bead injection. Using the susceptible naïve control as the standard, eight constitutively expressed polypeptides were specific to naïve susceptible mosquitoes while twelve other spots were reduced, enhanced or specific to refractory mosquitoes. Several of the strain-specific spots probably comprise related pairs (one in each strain) which vary only in isoelectric focusing point. Nine spots were induced by sham injection or by an injection of beads or saline, but none was reproducibly different between the strains. Amino acid sequence analysis of one of the refractory strain-specific spots identified it as AgSp14D1, an A. gambiae infection-responsive serine protease that is most similar to the Drosophila gene easter and Manduca prophenoloxidase activating enzyme. This gene maps to polytene chromosome division 14, which has been implicated in the melanization phenotype by quantitative trait loci mapping.

Inhibition of endothelium-dependent vascular relaxation by lysophosphatidylcholine: impact of lysophosphatidylcholine on mechanisms involving endothelium-derived nitric oxide and endothelium derived hyperpolarizing factor

Hyperlipidemia has been associated with an increase in the incidence of atherosclerosis. The oxidation of low density lipoprotein (LDL) plays an important role in the initiation and progression of atherosclerosis, one of its effects being the inhibition of endothelium dependent relaxation (EDR). The elevated level of lysophosphatidylcholine (LPC) in oxidatively modified LDL has been shown to be a biochemical factor responsible for the impairment of EDR in vascular ring preparations. Several endothelium-derived modulators are thought to control vascular responsiveness. The present work examined whether acetylcholine (ACh)-induced EDR in rat aorta (pre-contracted with phenylephrine, PE) involved both endothelium-derived nitric oxide (EDNO) and endothelium-dependent hyperpolarizing factor (EDHF) and whether LPC inhibited either of these selectively. Indomethacin (10(-5) M), had no significant effect on EDR, indicating that products of cyclooxygenase, including prostacyclin, are not involved. Treatment with either N(W)-nitro-L-arginine methyl ester (L-NAME, 6.8 microM) to inhibit the production of EDNO or with elevated K+ (15 mM), to block the hyperpolarizing effect of EDHF impaired EDR considerably (each of these shifting the inhibitory dose-response relationship to ACh by almost one log unit); in muscles treated with both of these agents EDR was completely inhibited. In each of L-NAME- and K-treated muscles, the addition of LPC (20 microM) further impaired EDR. LPC did not independently raise the tone of resting- or PE-contracted aorta. We conclude that the inhibition of EDR of rat aorta by LPC involves the actions of both EDNO and EDHF.

The menopausal experiences of women in a developing country: "there is a time for everything: to be a teenager, a mother and a granny"

The menopausal experiences of 26 Zimbabwean women were explored, using a structured open-ended interview schedule. Interviews were carried out in Harare in 1995. An analysis of the consensual data indicated that these women do experience the menopause symptoms that have been claimed elsewhere to be universal. Their experiences of menopause were not, however, regarded generally as distressing and were interpreted as a normal stage in the life cycle. Particular cultural beliefs are described which impact on women's understandings and reactions to the menopause.

The active sites of molybdenum- and tungsten-containing enzymes

Protein X-ray crystallography has revealed the structures of the active sites of several molybdenum- and tungsten-containing enzymes that catalyze formal hydroxylation and oxygen atom transfer reactions. Each molybdenum (or tungsten) atom is coordinated by one (or two) ene-dithiolate groups of a novel pterin (molybdopterin), and the active sites are further differentiated from one another by the number of terminal oxo and/or sulfido groups and by coordinated amino acid residues. These active-site structures have no precedent in the coordination chemistry of molybdenum and tungsten.

Menstrual and premenstrual experiences of women in a developing country

The menstrual and premenstrual experiences of black Zimbabwean women were examined. Twenty-five professional women and twenty-five domestic workers were interviewed using semistructured, open-ended interviews designed to explore their experiences. An analysis of consensual data indicated a number of predominant themes, including secrecy associated with menstruation, the negativity surrounding menarche, the breakdown of the traditional family network that passes on information about menstruation, and the acceptance of menstrual cycle experiences by the women. The main differences between the two groups concerned explanations of the functions and purpose of menstruation and the reporting of physical and affective symptoms. These differences are suggestive of the impact of educational level on experiences of menstruation.

Lay beliefs about diarrhoeal diseases: their role in health education in a developing country

This study examines the beliefs and understandings concerning diarrhoea among 2 groups of Zimbabwean women. Mothers with formal education are compared to those with less formal education. Differences and commonalities of beliefs are examined. The findings show that traditional explanations of an illness such as diarrhoea can inhibit health education campaigns against this disease which kills many children every year.

Reactions to repeated STD infections: psychosocial aspects and gender issues in Zimbabwe

This study explores psychosocial and gender issues related to multiple STD infections within the context of marriage. Thirty men and thirty women, currently married and attending a municipal clinic for treatment for repeated STD infections were interviewed. A semi-structured interview schedule was administered to explore themes of knowledge and beliefs about STDs, psychological reactions to repeated infections and power aspects of sexuality. It was found that men and women differed in how they interpreted and reacted to multiple STD infections. There was clear evidence of women's lack of power to negotiate safe sex within marriage and of the lack of social support networks for infected women.

The practice of testicular self examination: a comparative study of British and Zimbabwean undergraduates

The practice of testicular self examination was investigated amongst a sample of 170 British and 153 Zimbabwean male undergraduates using a questionnaire based on the health belief model. Knowledge of testicular cancer and of self examination was found to be low in both groups. Both groups, though, showed high general health awareness and a perception that the benefits of self examination would be great. It is recommended that knowledge of testicular cancer and the value of self examination should become part of general community based health programmes in both countries.

Perceptions of normal alcohol use held by Zimbabwean high school students

Perceptions of the normal or no-problem use of alcohol held by male and female high school students were investigated. A sample of 127 male and 113 female high school students were asked to indicate their perceptions of the normal use of alcohol for their own sex and the opposite sex using a structured questionnaire. The students were also asked to select from a list of reasons those reasons they considered were non-problem reasons for using alcohol. Male and female students set levels of normal alcohol use for males that were significantly higher than those set for females. Over half the male sample and a large proportion of the female students selected inappropriate reasons for using alcohol. Appropriate health education programmes based on these findings are discussed; in particular the need to educate adolescents to recognize and deal with their inappropriate reasons for using alcohol.

Students' knowledge of the use of herbs and other agents as preparation for sexual intercourse

Interest is growing in the use of herbal and other agents as a preparation for sexual intercourse. Concern has been expressed that such traditional practices, which are widespread in central and southern Africa, may increase women's risks of cervical cancer and infection with the human immunodeficiency virus. We examined the knowledge and beliefs associated with these practices in a sample of educated young men and women in Zimbabwe. We found that there was widespread knowledge of the use of herbs as a preparation for sex and that the purpose of the practice was to enhance men's sexual experience. Both men and women indicated ambivalent attitudes toward the practice; an interesting pattern of actual and perceived expectations was found. The need for preventive health education concerning these practices is discussed.

Chlamydia trachomatis, infertility, and population growth in sub-Saharan Africa

In sub-Saharan Africa, Neisseria gonorrhoeae and Chlamydia trachomatis are common infections. These pathogens are also the major causes of post-salpingitis tubal infertility, and infertility is a frequent problem in this region. A mathematical model, recently devised to estimate the effect of gonococcal infection on population growth, was used to estimate the potential effect of chlamydial infection on population growth. The model predictions for chlamydial infection were compared with those previously reported for gonococcal infection. The model predicts that both infections may be exerting severe effects on population growth at realistic prevalence rates of infection. The model also predicts that N. gonorrhoeae produces a steeper reduction in population growth than does C. trachomatis because its transmission dynamics result in a higher force of infection (incidence rate) at any given prevalence of infection. Large scale changes in the epidemiology of these infections can be expected to occur in sub-Saharan Africa because of improved sexually transmitted disease (STD) diagnosis and treatment services as a component of AIDS prevention. Changes in the epidemiology of gonococcal and chlamydial infection are predicted to result in accelerated population growth unless STD control programs are linked to effective contraception programs.

The use of herbal and other agents to enhance sexual experience

This study examines the use of herbal and other agents prior to sexual intercourse. This practice is thought to be common in central and southern Africa. The study comprises an analysis of the behavioural and psychological aspects of the practice. Structured interviews were conducted with 63 Zimbabwean women, 33 were attenders at an urban health clinic, 30 were nurses. Eighty-seven percent of the sample reported using herbs and other agents regularly as a preparation for sexual intercourse. The health and social consequences of such practices are examined; the problems of cervical cancer and HIV and their relation to these practices is discussed.

Inactivation of p53 gene in human and murine osteosarcoma cells

We examined structure and expression of the p53 and Rb genes in a C3HOS transplantable mouse model of osteosarcoma. The results were compared to analogous studies conducted with five human osteosarcoma cell lines. The p53 gene was found rearranged in the mouse tumour. The rearrangement mapped to the first intron region of the p53 gene and as a result, no p53 expression could be detected in C3HOS tumours. Using p53 genomic probes, we have detected the same rearrangement in the original radiation-induced tumour and the various clones that were isolated from it. Deletion and rearrangement of the p53 gene were also found in three out of five of the human osteosarcoma cell lines (MG-63, G-292, Saos-2). No p53 expression could be detected in these three cell lines. In the affected human osteosarcoma cell lines, the rearrangement involved the first intron region. In addition, the mouse tumor was analysed for structural and expression changes in the Rb and the c-myc genes. Normal expression of both genes were detected in the murine tumour. Only one (Saos-2) human osteosarcoma cell line exhibited gross structural alteration in the retinoblastoma gene. The results suggest that the inactivation of p53 may be an important step in the development of osteosarcomas, and that a rearrangement affecting the first intron is common in osteosarcomas.

Blockade of transgenic gamma delta T cell development in beta 2-microglobulin deficient mice

The gamma delta T cell receptor (TCR) of the hybridoma KN6 recognizes the self molecule encoded by a class I gene which maps within the TL region of the major histocompatibility complex (MHC) of H-2b mice. Mice transgenic (Tg) for this TCR were crossed with mice genetically deficient in beta 2-microglobulin (beta 2m). No mature Tg gamma delta T cells were detected in the thymus or the spleen of the beta 2m- gamma delta Tg mice. We conclude that interaction between the Tg gamma delta TCR and a beta 2m-associated molecule (probably an MHC class I molecule) is required for the generation of mature Tg gamma delta T cells.

Nurses' views of parasuicide in a developing country

This study examines the knowledge, beliefs, attitudes, intentions and experiences of nurses at various stages of their careers with regard to patients who have made suicide attempts. It focuses particularly on the relationship of traditional Shona beliefs about suicide and considers how they interact with western medical beliefs. A detailed questionnaire covering these elements was administered to three groups of nurses. They were sampled at either the beginning or end of their training or after approximately ten years experience. Knowledge of suicide was found to be poor and attitudes towards parasuicide were negative. Traditional beliefs were held strongly by all groups of nurses; western beliefs were strongest amongst experienced nurses. Practical implications of these attitudes and beliefs for training are considered.

Glyphosate skin binding, absorption, residual tissue distribution, and skin decontamination

Glyphosate is a broad-spectrum postemergence translocated herbicide. Its interactions with skin and potential systemic availability through percutaneous absorption was studied by skin binding, skin absorption, residual tissue distribution, and skin decontamination. Glyphosate in a final formulation (Roundup) undiluted and diluted with water 1:20 and 1:32, would not partition into powdered human stratum corneum (less than 1%). In vitro percutaneous absorption through human skin into human plasma as receptor fluid was no more than 2% over a concentration range of 0.5-154 micrograms/cm2 and a topical volume range of 0.014-0.14 ml/cm2. Disposition of glyphosate following iv administration of 93 and 9 micrograms doses to rhesus monkeys was mainly through urine excretion, 95 +/- 8 and 99 +/- 4% in 7 days, respectively. Percutaneous absorption in vivo in rhesus monkey was 0.8 +/- 0.6% for the low dose (25 micrograms/cm2) and 2.2 +/- 0.8% for the high dose (270 micrograms/cm2). No residual 14C was found in organs of the monkeys euthanized 7 days after the topical application. Washing the skin application site with soap and water removed 90 +/- 4% of applied dose, and washing with water only removed 84 +/- 3% of applied dose. Both soap and water and water only were equal in ability to remove glyphosate from skin over a 24 hr skin application period. About 50% of the initially applied dose could be recovered after 24 hr. Glyphosate is very soluble in water and insoluble in most organics (octanol/water log P = -1.70) and therefore not compatible with the lipid-laden stratum corneum.(ABSTRACT TRUNCATED AT 250 WORDS)

The biphasic modulation of inhibin mRNA levels and secretion by PMSG in rat granulosa cells in vitro

Granulosa cell cultures derived from diethylstilboestrol-treated immature rats were used to study the in vitro effect of pregnant mare serum gonadotrophin (PMSG) on steady state mRNA levels for the inhibin alpha and beta A subunits and the secretion of immunoreactive inhibin and progesterone. After 48 h treatment the dose-response curve of PMSG revealed a maximum stimulation (2.5-3.5 fold) of cytosolic alpha and beta A mRNAs over the range of 1 to 10 mU PMSG mL-1, with corresponding stimulation of inhibin secretion. A high dose of PMSG (160-500 mU mL-1) clearly suppressed inhibin alpha mRNA levels as well as inhibin secretion, whereas progesterone (P) was maximally stimulated (up to 600 fold). Although the level of cytosolic inhibin beta A subunit mRNA was also down-regulated by a high concentration of PMSG in the culture medium, the doses required to suppress its mRNA level to less than those of the control varied. These data demonstrate that low doses of follicle stimulating hormone/luteinizing hormone (FSH/LH)-like (PMSG) activity enhances and high doses decrease the steady-state mRNA levels of inhibin in rat granulosa cells in vitro; this biphasic regulation in vitro reflects the differential regulation of inhibin secretion observed during the rat oestrous cycle.

Percutaneous absorption and skin decontamination of PCBs: in vitro studies with human skin and in vivo studies in the rhesus monkey

Knowledge of the entry of polychlorinated biphenyls through the skin into the body and subsequent disposition aids estimation of potential for human health hazard. [14C]Aroclor 1242 and [14C]Aroclor 1254 were separately administered intravenously and topically to rhesus monkeys. Following iv administration, 30-d excretion was 39.4 +/- 5.9% urine and 16.1 +/- 0.8% feces (total 55.5 +/- 5.1%) for Aroclor 1242, and 7.0 +/- 2.2% urine and 19.7 +/- 5.8% feces (total 26.7 +/- 7.5%) for Aroclor 1254. Mineral oil and trichlorobenzene are common PCB cosolvents in transformers. Skin absorption of Aroclor 1242 was 20.4 +/- 8.5% formulated in mineral oil and 18.0 +/- 3.8% in trichlorobenzene (p greater than .05). Absorption of Aroclor 1254 was 20.8 +/- 8.3% in mineral oil and 14.6 +/- 3.6% in trichlorobenzene (p greater than .05). PCBs are thus absorbed through skin, and excretion from the body is slow. Vehicle (trichlorobenzene or mineral oil) did not affect percutaneous absorption. In vitro skin absorption in human cadaver skin did not correlate with in vivo findings. This was due to lack of PCB partition from skin into the water receptor fluid, even with addition of 6% Oleth 20 (Volpo 20) solubilizer. Skin decontamination of PCBs showed soap and water to be as effective as or better than the solvent ethanol, mineral oil, and trichlorobenzene in removing PCBs from skin. There is a dynamic time lapse for PCBs between initial skin contact and skin absorption (irreversible removal). Thus initially most PCBs could be removed from skin, but this ability decreased with time to the point where at 24 h only about 25% of the initial PCB skin dose could be recovered with skin washing.