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.

Press coverage of AIDS in Zimbabwe: a five-year review

Five years of newspaper coverage of HIV and AIDS in Zimbabwe is examined. Both the number of items and the amount of space devoted to the topics has increased steadily over the 5 years. The nature and content of the items show a continuing bias towards issues more closely associated with western patterns of the epidemic, and comparative neglect of personal stories, local issues and items with a counselling focus. Language is also examined and found to reflect a victim and war imagery. The implications for health education in the country are considered and specific recommendations for more constructive media coverage are made.

Clinician responses to sexual abuse allegations

We conducted a survey using an experimental design to identify how and to what extent specific personal and case factors affect clinicians' judgments about sexual abuse allegations. We drew a stratified random sample of 1,635 United States clinicians from national directories of clinical social work, pediatrics, psychiatry and psychology. Six hundred and fifty-six completed questionnaires were obtained, yielding a 42% response rate. We asked each subject to read and rate, on a 6 point scale, 16 vignettes alleging sexual abuse. The scale ranged from 1 (very confident it did not occur), to 6 (very confident it did occur). On average, respondents were "slightly confident sexual abuse had occurred" (M = 4.03; SD = 0.6). This finding was significantly different from a mean of 3.50, which is the expected null result. Seven case factors affected credibility ratings at the .01 level; perpetrators' race (Caucasians viewed as perpetrators more than minorities); perpetrators' relationship to victim (family members more often seen as perpetrators); victims' race (minorities more credible as victims); victims' affect (those showing negative affect more believable); age (younger victims more often seen as victimized); behavioral changes in the victim; and perpetrator's history of substance abuse. Six clinician factors were significant at the .05 level: age (younger clinicians were more credulous), gender (females more credulous), discipline (clinical social workers more credulous), theoretical orientation (family systems oriented more credulous) and personal history of sexual or physical abuse (abuse history more credulous).

No joking matter: formal and informal sources of information about AIDS in Zimbabwe

One hundred and forty-two social work students in Harare, Zimbabwe, were questioned concerning their sources and memory of information concerning the human immunodeficiency virus (HIV) and AIDS. Newspapers were cited most frequently as the major source of information. Family and friends were not reported to be major sources of information. An analysis of the kinds of items most frequently recalled showed that articles concerning personal portrayals were the most powerful vehicles for AIDS information. Metaphors and similes for AIDS produced by the students mirrored those commonly reported elsewhere. Jokes were studied as indicators of informal opinions, and these showed negative views of American involvement in AIDS issues.

A comparative binding of platinum anti-tumour compounds to plasma proteins in the rat (in vivo) and mouse (in vitro)

Plasma protein binding of 195mPt-labelled cisplatin, carboplatin and iproplatin has been studied in vivo in rat and in vitro in mouse, using both electrophoresis and trichloroacetic acid precipitation. After intravenous injection plasma clearance rates were biphasic for all 3 compounds, (t1/2 alpha, 13-17 min) but cisplatin was retained thereafter longer than the others. By 5 min, gel electrophoresis showed protein labelling with all 3 drugs but none involved low mol.wt. proteins (< 16 kDa). At 2 h a notable proportion of the protein bound platinum was associated with the latter components. There was a general resemblance between the distribution patterns of cisplatin and carboplatin whereas iproplatin showed a persistent retention of the label with time to higher mol. wt. proteins. From in vitro incubation with mouse plasma, rates of interaction respectively were cisplatin t1/2 alpha, 35 min, beta 8 h, carboplatin t1/2, 44 h and iproplatin t1/2, 104 h. By electrophoresis the protein bound fraction pattern (1 h) was again similar for cisplatin and carboplatin with virtually no binding to low mol. wt. proteins. After 24 h these were now involved to a high degree (40%). Iproplatin showed relatively marked binding to proteins of higher mol. wt. but no transfer with time to the low mol. wt. protein zone. A possible explanation is the need for in vivo metabolism for this compound as manifest in the rat. It is suggested that the significance of interaction with low mol. wt. proteins merits further investigation in relation to the antitumour and toxicological actions of these drugs.

A highly potent and selective receptor antagonist from the venom of the Agelenopsis aperta spider

Agatoxin-489, extracted from the venom of the Agelenopsis aperta spider, was studied on acutely isolated perfused hippocampal neurons of rat using the concentration clamp technique. Agatoxin-489 proved to be a selective N-methyl-D-aspartate antagonist; responses to applications of N-methyl-D-aspartate or L-aspartate were blocked by concentrations of agatoxin-489 ranging between 0.1 nM and 1 microM, while responses to kainate were not affected by agatoxin-489 at concentrations up to 10 microM. The actions of agatoxin-489 against responses to N-methyl-D-aspartate or L-aspartate were use- and voltage-dependent, being less pronounced with an increase in the holding potential from -100 to -30 mV. The action of agatoxin-489 could be completely or partially reversed only after washout in the presence of an N-methyl-D-aspartate agonist. The washout was more effective at positive membrane potentials ranging from 0 to +20 mV. These results imply that the spider toxin agatoxin-489, like dizocilpine, is a potent and selective N-methyl-D-aspartate antagonist which preferentially interacts with activated N-methyl-D-aspartate receptors and/or open N-methyl-D-aspartate-activated ionic channels.

Symptomatic response to antipsychotics differs between recent onset and recurrent chronic schizophrenic patients

The symptomatic response to standard antipsychotic treatment was assessed over the first 4 weeks of hospitalisation in 39 patients with DSM-III schizophrenia, active phase, using the Brief Psychiatric Rating Scale (BPRS). While highly significant improvement was noted overall, 36% of patients either did not improve or worsened. Furthermore there was no diminution in the withdrawal-retardation factor of the BPRS. Patients experiencing their first admission to hospital, all with recent-onset illness, were then compared with patients who presented with a recurrence and had illness of at least 3 years duration. Despite similarities in overall response, withdrawal-retardation scores did not diminish in recent-onset patients, in contrast to multiple admissions who demonstrated significant improvement. These findings suggest greater responsiveness of negative symptoms to treatment in patients with longstanding illness, and possibly a poorer prognosis in first admission patients with deficit manifestations.

Cell-targeted 114Inm and drug (BCNU) combination therapy in a rat acute lymphoblastic leukaemia

A proportion of syngeneic female rats inoculated intramuscularly with a lethal T-cell lymphoblastic (Roser) leukaemia are cured by a single intraperitoneal injection of bischloroethylnitrosourea (BCNU) (Carmustine) (10 mg kg-1) given towards the end of the preleukaemic phase (day 7). Additional therapy on day 4, using intravenous leukaemia cells lethally labelled with the radionuclide 114Inm, enhanced the overall cure rate by 30%. The spleen is a major site of indium concentration from the targeting cells so that the continuous local radiation field appears to result in a substantial reduction of the body load of leukaemia cells in the enlarged spleen particularly, thus enhancing the curative potential of the drug. The results demonstrate in principle that in patients in remission a single dose of targeted radiotherapy in the spleen combined sequentially with an appropriate drug might provide considerable aid in eliminating a residual population of leukaemia cells.