Bilateral blindness due to trauma in Cambodia

Ocular trauma is a major cause of monocular blindness in both the developed and developing world, but is not seen as a significant cause of bilateral blindness. Trauma is therefore generally thought of as a major cause of blind eyes without being a major cause of blind people. Because of the difficulties of surgical treatment of ocular trauma in many developing countries, long-term management is usually aimed at prevention, e.g. by improving safety standards in the workplace. The situation in countries such as Cambodia, which have high landmine densities, is different. Cambodia has an estimated 4-10 million landmines which cause significant morbidity and mortality. This hospital-based study of blindness in the north-west of Cambodia found that of 453 bilaterally blind individuals, 17 (4%) were blind as a result of trauma, and 14 of these were males 15-35 years old. Fourteen cases were due to bilateral penetrating injuries caused by landmine explosions, and usually occurred in association with other severe injury. The other main causes of blindness were cataract (59%), glaucoma (14%) and corneal scarring (12%). Penetrating ocular trauma is a significant cause of bilateral blindness in Cambodia, and predominantly affects young men. It is estimated that it would take 250 years to clear Cambodia of landmines at current activity levels.

Retinopathy in haemoglobin C trait

Retinopathy associated with sickle-C and sickle cell disease is well described. Sickle trait and haemoglobin C trait are generally considered benign conditions, with infrequent systemic manifestations. Rare cases of retinopathy in sickle trait, in the presence of contributory factors, exist and we recently reported three such patients. The occurrence of retinopathy in haemoglobin C trait is even less well documented. Haemoglobin C does not cause red blood cell sickling but is known to decrease erythrocyte plasticity and increase blood viscosity. We report three cases in which haemoglobin C trait was associated with significant peripheral vascular occlusion and seafan formation (confirmed by fluorescein angiography) similar to that seen in sickle retinopathy. Two patients had coexistent systemic disease (hypertension and diabetes mellitus). Vitreous haemorrhage was the presenting feature in two patients. It is evident that haemoglobin C trait may be associated with sight-threatening complications.

Baculovirus-mediated high level expression of a human thiopurine methyl transferase

We have expressed the human thiopurine methyltransferase cDNA in a baculovirus vector in Sf21 (Spodoptera frugiperda) cells. This system expresses the enzyme at levels such that the thiopurine methyltransferase enzyme may be readily visualised by Coomassie blue stained sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The expressed enzyme catalysed the methylation of 6-mercaptopurine with an apparent Km of 892 microM, similar to that observed in human liver cytosol ie. 657 microM however, the Vmax was 13,500 pmole/mg/min, which is approximately 400 times higher than the Vmax observed in human liver cytosol ie. 33 pmole/mg/min. The thiopurine methyltransferase inhibitors 6-thioxanthine, p-methoxybenzoic acid and 3,5-dimethoxy benzoic acid were found to be potent inhibitors of the expressed enzyme.

Developing AIDS care in Zimbabwe: a case for residential community centres?

New support services are needed as the AIDS epidemic escalates. Home care has been the cornerstone of new developments in Zimbabwe and the southern African region, essentially resource-strapped countries. However, while home care has many benefits, levels of coverage are often low and many patients at some phase of their disease need more than their home can provide, even with access to support services. Hospital admission is often not a viable option and the need may arise for some form of respite or hospice community centre to provide residential care. This option is debated and potential benefits and pitfalls are explored.

Sickle retinopathy in patients with sickle trait

Sickle trait is traditionally considered a benign condition by ophthalmologists. Three cases of sickle retinopathy in subjects with sickle trait are reported. In all cases the onset of retinopathy was related to other contributing factors: in one case a traumatic hyphaema and raised intraocular pressure, in two others diabetes mellitus. Patients with sickle trait are at risk of retinopathy if coincident ocular or systemic disease is present.

Incidence of acute symptomatic toxoplasma retinochoroiditis in south London according to country of birth

OBJECTIVE

To determine the incidence of acute symptomatic toxoplasma retinochoroiditis presenting to ophthalmologists for patients born in Britain and elsewhere.

DESIGN

Population based, cross sectional study.

SETTING

11 districts in south Greater London.

SUBJECTS

All patients presenting to NHS ophthalmologists with symptoms due to acute toxoplasma retinochoroiditis in 1992-3.

MAIN OUTCOME MEASURE

Intraocular inflammation in association with a retinochoroidal scar, active adjoining retinitis, and IgG serum antibodies to toxoplasma.

RESULTS

The estimated incidence of acute symptomatic retinochoroiditis for all people born in Britain was 0.4/100,000/year. If a mean of two symptomatic episodes per lifetime is assumed, 100 people born in Britain may be affected each year, about a fifth of the estimated 500-600 congenitally infected people born each year.

CONCLUSIONS

A substantial proportion of people with acute symptomatic toxoplasma retinochoroiditis were born outside the country, and the number born in Britain was smaller than the number previously estimated to develop retinochoroidal lesions due to congenital toxoplasmosis. These findings suggest that prenatal screening for toxoplasmosis in Britain may be of limited benefit.

A turnover study in the male rat of plasma-bound 59Fe, 114Inm and 109Cd with particular reference to the gonad

After intravenous doses of the plasma-bound radionuclides 59Fe, 114Inm and 109Cd, only a minute percentage localizes in the rat testis and remains largely unchanged with time. Intratesticular injection of appropriately reduced volumes led to much higher proportionate percentage retention of 14, 65 and 11 for 59Fe, 114Inm and 109Cd, respectively. By this route, significant feedback of the elements escaping initial binding was prevented. Distinct but different testicular turnovers were now discernible. As a receptor of fluid and spermatozoa from the testicular tubules, the epididymis provides an indication of entry into and interaction of the metals with spermatogenic cells. For 59Fe no measurable changes were detected, whereas a progressive increase in epididymal 114Inm occurred, which had not reached a plateau by 70 days. 109Cd, now demonstrated within the testicular tubules by autoradiography, remained at constant organ level for upwards of 16 days but had declined by 25% by 57 days. At this point, the epididymis showed a five-fold increase in the radionuclide, declining to one-half this value by 126 days. Since 109Cd is carrier free, the data reflect a body turnover of dietary cadmium. These results, overall, are compatible with the entry of a proportion of each radionuclide into the seminiferous tubules and reaction with spermatogenic cells. Possible interpretations of the observed differences are presented.

Orphan prevalence and extended family care in a peri-urban community in Zimbabwe

An orphan enumeration survey was conducted in 570 households in and around Mutare, Zimbabwe in 1992; 18.3% (95% CI 15.1-21.5%) of households included orphans. 12.8% (95% CI 11.2-14.3%) of children under 15 years old had a father or mother who had died; 5% of orphans had lost both parents. Orphan prevalence was highest in a peri-urban rural area (17.2%) and lowest in a middle income medium density urban suburb (4.3%). Recent increases in parental deaths were noted; 50% of parental deaths since 1987 could be ascribed to AIDS. Orphan household heads were likely to be older and less well-educated than non-orphan household heads. The majority of orphaned children were being cared for satisfactorily within extended families, often under difficult circumstances. Caregiving by maternal relatives represents a departure from the traditional practice of caring for orphans within the paternal extended family and an adaptation of community-coping mechanisms. There was little evidence of discrimination or exploitation of orphaned children by extended family caregivers. The fact that community coping mechanisms are changing does not imply that extended family methods of caring are about to break down. However, the emergence of orphan households headed by siblings is an indication that the extended family is under stress. Emphasis needs to be placed upon supporting extended families by utilizing existing community-based organizations. Orphan support programmes may need to be established initially in high risk communities such as low-income urban areas and peri-urban rural areas.

Differential effects of transforming growth factor-beta 1 on distinct developmental stages of murine megakaryocytopoiesis

The effect of transforming growth factor-beta 1 (TGF beta 1) on three developmental stages of megakaryocytopoiesis was investigated. Using a murine bone marrow agar culture system, titrated doses of TGF beta 1 were added to cultures assaying primitive high proliferative megakaryocyte progenitors, committed megakaryocyte precursors, and nondividing, endoreduplicating megakaryocytes. The growth of high proliferative megakaryocyte colony-forming cells (HPP-CFU-Mk) that require the growth factors interleukins-1, 3 and 6 (IL-1 + IL-3 + IL-6) for colony detection was abrogated by the addition of 1 ng TGF beta 1/ml. The sensitivity of committed megakaryocyte progenitors (colony-forming unit-megakaryocyte, CFU-Mk) to TGF beta 1 depended on the growth factor combination. TGF beta 1 (1 ng/ml) completely inhibited megakaryocyte colony formation from CFU-Mk only in cultures stimulated by low doses of IL-3. TGF beta 1 (> 10 ng/ml) could only marginally inhibit megakaryocyte colony formation generated in the presence of either high doses of IL-3 or the combination of low dose IL-3 + IL-6. TGF beta 1 inhibited both IL-3-dependent and IL-6-dependent megakaryocyte growth but tenfold higher doses of TGF beta 1 were required to inhibit growth generated by the combination of IL-3 + IL-6. The data showed that the capacity of TGF beta 1 to inhibit distinct differentiation stages of the megakaryocytopoietic lineage depended on the concentration and combination of growth factors involved.

Classes of primitive murine megakaryocytic progenitor cells

We describe high proliferative potential colony-forming cells-megakaryocyte (HPP-CFU-Mk) from mouse bone marrow preparations using known cytokine combinations. These primitive precursors, which generate at least 80 megakaryocytes per colony, were detected from bone marrow populations enriched for primitive cells, either following treatment with 5-fluorouracil (5-FU) or after enrichment from normal bone marrow using immunological procedures. HPP-CFU-Mk were most reproducibly grown in the presence of interleukin-1 (IL-1) plus IL-3 plus IL-6, and mostly grew as a single large aggregate, rarely forming multiple foci. Cell separation studies showed that the HPP-CFU-Mk have membrane properties that characterized these cells as being intermediate between high proliferative myeloid primitive progenitors (high proliferative colony-forming cells [HPP-CFC]) and committed megakaryocyte progenitors (CFU-Mk). The data show that HPP-CFU-Mk can be designated as primitive cells on the basis of their being spared in vivo after 5-FU treatment, their proliferative potential to produce megakaryocytes, and their cofractionation with a proportion of primitive myeloid progenitor cells.

Spermatogenic and mutagenic damage after paternal exposure to systemic indium-114m

The cytotoxic and mutagenic consequences of systemic administration of 114mIn have been examined. Adult male rats were dosed intraperitoneally with 14.8 or 3.7 MBq/kg 114mIn. Approximately 0.25% of the injected radioactivity was localized within the testis by 24 h and was retained with an effective half-life of 49.5 days. Breeding studies were started 3 days after injection, males being housed with two females for seven consecutive mating trials of 19 days, separated by 2 days. Indium-114m caused a reduction in litter size and an increase in the incidence of pre- and postimplantation losses and dominant lethal mutations. These effects became evident from 24 days but were most marked between 87-126 days after treatment and persisted up to 147 days. When animals were mated 200 days after treatment, no significant changes were observed. In a parallel study, administration of 14.8 MBq/kg 114mIn resulted in decreased testis and epididymal weight and sperm reserves. Maximal reduction occurred between 87-108 days after injection followed by recovery toward control values, but neither organ had reached normal levels at 200 days. A single dose of 3.7 MBq/kg, however, had no effect on reproductive organ weight or sperm content. Male F1 progeny from the 14.8 MBq/kg group of the second mating period (commencing at 24 days) displayed decreased testis weights and sperm content and provoked a higher incidence of dominant lethal mutations. This effect was not observed in male progeny from any other time or the alternative dose level.

Personal history of childhood abuse among clinicians

We conducted a survey to determine the prevalence, characteristics, and effects of a history of childhood sexual and physical abuse among professionals responsible for evaluating child sexual abuse allegations. A gender-stratified random sample of 1,635 United States clinicians was drawn from the most current national directories of clinical social work, pediatrics, psychiatry, and psychology. We received 656 completed questionnaires, yielding a 42% response rate. Thirteen percent of the men and 20% of the women reported a personal history of childhood sexual abuse; 7.3% of the men and 6.9% of the women reported a history of physical abuse as children. The modal age at which both genders were sexually abused was 8 years. The modal age at the time of physical abuse was 10 years for both sexes. Of those sexually abused, 50% of both genders were sexually abused for only 1 year. Of those physically abused, more than 50% of both genders were physically abused for 3 or more years. Older females were more likely to report a history of sexual abuse than were their younger cohorts. In this population, physical abuse was overwhelmingly perpetrated by parents. However, the modal perpetrators of sexual abuse (for both females and males) were male acquaintances or male strangers. Fathers and stepfathers were unlikely to be perpetrators of sexual abuse (3% for males and 12% for females) in this sample. For both genders, particularly males, sexually abused respondents were less likely to be married than their nonabused cohorts. Both men and women who had been sexually abused were more likely to be in nonmarital relationships than were those who had not been sexually abused. Women who had been sexually abused were less likely to have raised children than were women who had not been sexually abused. Respondents who had been sexually abused and/or physically abused were more likely to believe allegations of sexual abuse contained in 16 vignettes alleging sexual abuse.

Does topical flurbiprofen affect the pupillary response to acetylcholine?

Pre-operative topical non-steroidal anti-inflammatory drugs (NSAIDs) are known to be effective in maintaining pupillary dilation during cataract surgery. However, previous studies have suggested that pre-treatment with these agents interferes with the miosis produced by intraoperative acetylcholine injection. This study was designed to determine whether the pupillary response to acetylcholine injection is reduced following pre-operative topical flurbiprofen 0.03%. Pupil diameters were measured with a millimetre rule, and the measurements verified using computerised image analysis of digitised video images. Eyes treated with flurbiprofen were compared with controls. There was no significant difference in pupillary diameter before corneal incision, but following aspiration of soft lens matter and insertion of intraocular lens the pupil was significantly larger in the flurbiprofen group (p = 0.002). At 1.0, 2.5 and 5.0 minutes following injection of acetylcholine no significant difference in the degree of miosis was detected. This study confirms that topical flurbiprofen maintains dilation during cataract surgery, and does not find any evidence to suggest that intra-operative response to acetylcholine is reduced.

Exogenous Nocardia asteroides endophthalmitis following cataract surgery

We present a case of Nocardia asteroides endophthalmitis following cataract surgery. It is the second to be reported and the first in which vision has been preserved. Symptoms commenced 5 days after surgery and there followed a chronic relapsing anterior uveitis which lasted for 4 months. Nocardia asteroides was finally cultured from an aqueous aspirate and a combination of specific antimicrobial treatment and surgery resulted in a satisfactory visual outcome. Exogenous nocardial intraocular infection is rare and must be distinguished from fungal infection as the organism is resistant to antifungal agents.

Pathways for PREP: a consumer-orientated model

This article describes the development of a responsive and dynamic model for the provision of postregistration education, encompassing local, national and professional issues.