Towards the development of brain injury specialists

Brain injury presents a hugely complex, and sometimes daunting arena for the rehabilitation professional. With disruption to a person's core sense of self being almost the sine qua non of brain injury, rehabilitation can cover physical, psychological, social, philosophical and psychiatric realms. Those with brain injury can also be amongst the most vulnerable people in our society. Their rehabilitation has profound implications socio-politically, both in how we seek to understand disturbance in others, and also how we strive to ameliorate it. Whilst both theory and practice have grown exponentially over the last two decades, there is still no formal training or qualification within the brain injury rehabilitation field. This paper discusses the need for such formal training at both a theoretical and practical level not only for clinicians but also for front line staff, families and primary care services. The difficulties inherent in providing co-ordinated and structured training in such a complex area are discussed, and finally a model that attempts to meet user needs is outlined.

Outcome of cataract surgery in patients with retinitis pigmentosa

AIM

To determine the visual benefit of cataract extraction in patients with retinitis pigmentosa and to identify risk factors for poor outcome.

METHODS

A retrospective analysis was undertaken of a continuous series of 142 eyes of 89 patients with retinitis pigmentosa undergoing cataract surgery between 1985 and 1997.

RESULTS

Mean age at surgery was 47.5 years (range 24-81 years). In 100 eyes there was posterior subcapsular lens opacity alone, 37 eyes also had moderate nuclear sclerosis, and five had only nuclear sclerosis. All patients had central visual fields of <10 degrees. Overall, mean visual acuity improved from 1.05 (SD 0.38) preoperatively to 0.63 (SD 0.49) postoperatively on the logMAR scale. Significant postoperative capsular opacification occurred in 88/139 eyes (63%) and 45.1% required capsulotomy. Anterior capsulotomy was undertaken in 5/52 (9.6%) eyes undergoing phacoemulsification. Postoperative macular oedema was noted in 20 (14%) eyes. Visual acuity improved in 109 eyes (77%), was unchanged in 29 eyes (20.5%), and worsened after surgery in four eyes (2.5%). 86/89 patients reported major improvement of visual function.

CONCLUSIONS

Cataract surgery for relatively minor lens opacities is beneficial in patients with retinitis pigmentosa, and most report subjective improvement of visual symptoms. The incidence of capsular opacification is high and anterior capsular contraction may occur. The number of eyes with poor vision due to macular oedema was unexpectedly low.

Efficacy of topical phenol decontamination strategies on severity of acute phenol chemical burns and dermal absorption: in vitro and in vivo studies in pig skin

Pure phenol is colorless and used in the manufacture of phenolic resins, plastics, explosives, fertilizers, paints, rubber, textiles, adhesives, pharmaceuticals, paper, soap, and wood preservatives. The purpose of this study was to compare the efficacy of several phenol decontamination strategies following dermal exposure using the pig as a model for human exposure, and then assess the effect of the two best treatments on phenol absorption in the isolated perfused porcine skin flap (IPPSF). Six anesthetized Yorkshire pigs were exposed to 89% aqueous phenol for 1 min using Hilltop chambers (10 skin sites/pig; 400 microl/site). Exposure to phenol was followed by one of 10 different decontamination procedures: 1-, 5-, 15-, and 30-min water wash; Ivory soap solution; polyethylene glycol (PEG 400); PEG 400/industrial methylated spirits (IMS); PEG 400/ethanol (EtOH); polyvinyl pyrrolidone (PVP)/70% isopropanol (IPA); and 70% IPA. For each of the last five strategies, 1-min treatment washes were repeatedly alternated with 1-min water washes for a total of 15 min. Evaluation was based on scoring of erythema, edema, and histological parameters such as intracellular and intercellular epidermal edema, papillary dermal edema, perivascular infiltrates, pyknotic stratum basale cells, and epidermal-dermal separation. It was concluded that PEG 400 and 70% IPA were superior to the other treatments investigated and equally efficacious in the reduction of phenol-induced skin damage. In addition, phenol absorption was assessed utilizing the two most effective in vivo treatments in the IPPSF. The assessment of percutaneous absorption of phenol found the PEG 400, 70% IPA, and 15-min water treatments significantly (P < 0.05) reduced phenol absorption relative to no treatment.

Improving access for rural Australians to treatment for anxiety and depression: The University of Melbourne Depression and Anxiety Research and Treatment Group-Bendigo Health Care Group initiative

Rural Australians have limited access to care for mental health problems. We describe a collaboration between the University of Melbourne Departments of Psychology and Psychiatry and a rural Area Mental Health Service to provide a specialist anxiety and depression treatment service in rural Victoria. The clinical service and the education and training approach are described.

Cognitively oriented psychotherapy for early psychosis (COPE): a 1-year follow-up

OBJECTIVES

Cognitively oriented psychotherapy for early psychosis (COPE) is aimed at facilitating the adjustment of the person, and at preventing or alleviating secondary morbidity in the wake of the first psychotic episode.

DESIGN

A total of 80 people participated in the initial trial and completed assessments on a range of outcome measures. Post-treatment assessment results from a non-randomized controlled trial of COPE have been previously reported. The present paper describes the results obtained from 51 patients who attended a follow-up assessment 1 year subsequent to the end-of-treatment assessment.

METHOD

The 51 patients formed three groups: (1) those who were offered and accepted COPE; (2) those who were offered COPE but refused it, and continued to receive other services from the Early Psychosis Prevention and Intervention Centre (EPPIC) (refusal subjects); and (3) those who were offered neither COPE nor any other continuing treatment from EPPIC (control subjects).

RESULTS

At 1-year follow-up, there was only one significant difference and this was between the COPE and refusal groups on the Integration/Sealing Over (I/SO) measure (p = .008). End-of-treatment differences were mostly sustained over the 1-year follow-up period. When the complete sample of 80 was considered, there were no differences between the three groups in terms of hospital admissions, community episodes, or time taken to first in-patient re-admission.

CONCLUSIONS

The study was weakened by the poor follow-up rates in the two control groups. This reduced power to detect differences between groups on the seven major measures. However, the relapse data gathered on the complete set of 80 patients were discouraging and suggest that the present formulation of COPE does not confer any advantage to those patients receiving the therapy over those not receiving the therapy.

Measurement of the charged pion electromagnetic form factor

Separated longitudinal and transverse structure functions for the reaction 1H(e,e(')pi(+))n were measured in the momentum transfer region Q2 = 0.6--1.6 (GeV/c)(2) at a value of the invariant mass W = 1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parametrization fitted to very low Q2 elastic data.

Does early hospital discharge with home support of families with preterm infants affect breastfeeding success? A randomized trial

The aim of the present study was to determine if earlier discharge of preterm infants (<37 wk) from hospital is safe and if it affects breastfeeding rates. In a pilot observational study, premature infants received full oral (sucking) feeds for a mean (SD) 7.7 +/- 7.9 d before discharge. In the main study, 308 preterm infants were randomly assigned to either Early Discharge (148 infants) when fully orally fed but not yet gaining weight or Routine Discharge (160 infants) when fully orally fed and also gaining weight before discharge. A further 122 mothers declined randomization. The Early Discharge group was followed by Visiting Nurse Specialists who were available 24 h a day, while the Routine group was followed by the Home Care Nurses available on week days. There were no significant differences between the groups in birthweight or gestational age. The Early Discharge group were discharged 2.5 +/- 2 d after full oral feeding compared to 4.4 +/- 2.7 d for the Routine group (p < 0.001) and 6.1 +/- 5 d for those who declined. However, there was no significant difference between the Early and Routine groups for breastfeeding either at discharge (80 vs 83%), or 6 wk (55 vs 60%) or 6 mo after discharge (36 vs 36%), or for weight gain, or rates of re-hospitalization (8.8% vs 11.9% at 6 wk, p = 0.37).

CONCLUSION

Early discharge from hospital once a preterm infant can take full oral feeds does not alter later breastfeeding rates when adequate visiting nursing support is available.

Spleen-targeted 114In(m) via normal and heat-damaged red cells in the mouse: isotope distribution and bone marrow damage

114In(m)-labelled heat-damaged erythrocytes (HDRBC) in BDF1 mice were quantitatively much less successful in spleen targeting than in the rat. Unheated labelled cells (NRBC) were an even less effective vector. Radiobiological effects manifest in the spleen (weight loss) and white cell count were nevertheless substantial, comparable in both groups and unchanged after 14 days. Considerable early renal loss of indium is inferred in the NRBC animals, but in the HDRBC group a high proportion was retained in the liver. Progenitor cell marrow cultures indicated acute transitory lethal effects with only partial recovery at termination; the marrow concentration of indium was the same in both groups.

Oral oseltamivir in human experimental influenza B infection

Oseltamivir is the prodrug of Ro64-0802 (GS4071), a potent and selective inhibitor of influenza A and B virus neuraminidases. Three randomized, double-blind, placebo-controlled, parallel-group studies evaluated oral oseltamivir for early treatment (75 or 150 mg twice daily for 5 days) or prevention (75 mg once or twice daily for 7 days) of experimental influenza B virus infection in healthy susceptible adults. Treatment study A (n=60) demonstrated similar trends to treatment study B (n=117), in which 75 mg doses of oseltamivir introduced 24 h after inoculation reduced median area under curve (AUC) virus titre (oseltamivir, 22.7; placebo, 131.1 log10 TCID50 x h/ml; P=0.002) and duration of viral shedding (oseltamivir, 23.9 h; placebo, 95.8 h; P=0.0005). In prevention study C (n=58), oseltamivir did not reduce infection rates (85 versus 84%) but significantly reduced median AUC virus titre (10.0 versus 66.9 log10 TCID50 x h/ml; P=0.03) and duration of viral shedding (36 versus 84 h; P=0.03) compared with placebo. Oseltamivir was well tolerated. No emergence of drug-resistant variants was detected by testing last-day isolates (n=112) in neuraminidase inhibition assays. These results indicate that oseltamivir has significant antiviral activity in experimental human influenza B virus infection when used for prophylaxis or early treatment.

Immunohistochemical expression of bcl-2 and p53 oncoproteins: correlation with Ki67 proliferation index and prognostic histopathologic parameters in colorectal neoplasia

The bcl-2 oncogene plays an important role in carcinogenesis by inhibiting cell death (apoptosis). It was initially discovered in follicular B cell lymphoma with t(14,18) and subsequently found in other malignant and premalignant lesions. Alteration of the normal controls of cell proliferation is also a significant factor in the multistep process of tumorigenesis. The proliferative activity of a given lesion is commonly evaluated by MIB 1, a monoclonal antibody to Ki67 proliferation antigen. Mutation of the p53 gene is considered the most common genetic aberration in colorectal cancer. Immunohistochemical (IHC) staining expression of bcl-2, Ki67, and p53 was retrospectively investigated in a series of 52 colorectal carcinomas and 56 adenomas. The aim of the study was twofold: (i) to investigate any correlation between MIB 1, p53, and bcl-2 immunostaining expression in colonic adenomas and carcinomas and (ii) to identify any relation between these markers and several histopathologic parameters including tumor size, pathologic stage, lymph node metastasis, angiolymphatic invasion, tumor grade, and differentiation in colon carcinomas. bcl-2 was consistently higher in adenomas than in carcinomas. There were 44 of 56 (78.6%) adenomas and 27 of 52 (51.9%) carcinomas positive for bcl-2 (P = 0.004). The mean Ki67 labeling index (LI) was 30.05 +/- 7.6 and 38.12 +/- 11.01 in adenomas and carcinomas, respectively (P = 0.0001). p53 was significantly higher in carcinomas (35 of 52 [67.3%]) than in adenomas (18 of 56 [32.1%]) (P = 0.0004). Expression of bcl-2 in carcinoma was associated with a lower p53 levels and lower mean Ki67 LI and with favorable histopathologic parameters. Higher p53 and Ki67 values were associated with prognostically poor histopathologic features (differentiation and Duke's stage). We conclude that, in contrast to p53 and Ki67, bcl-2 oncoprotein expression is probably an early step in the process of colon carcinogenesis, and its expression may be associated with favorable pathologic parameters. Furthermore, an inverse relation exists between p53 and Ki67, and bcl-2 IHC expression in colonic neoplasia. Evaluation of bcl-2, p53, and Ki67 IHC expression in colonic carcinoma may be of value in predicting the clinical course in these patients.

Combinations of variations in multiple genes are associated with hypertension

The genetic analysis of hypertension has revealed complex and inconsistent results, making it difficult to draw clear conclusions regarding the impact of specific genes on blood pressure regulation in diverse human populations. Some of the confusion from previous studies is probably due to undetected gene-gene interactions. Instead of focusing on the effects of single genes on hypertension, we examined the effects of interactions of alleles at 4 candidate loci. Three of the loci are in the renin-angiotensin-system, angiotensinogen, ACE, and angiotensin II type 1 receptor, and they have been associated with hypertension in at least 1 previous study. The fourth locus studied is a previously undescribed locus, named FJ. In total, 7 polymorphic sites at these loci were analyzed for their association with hypertension in 51 normotensive and 126 hypertensive age-matched individuals. There were no significant differences between the 2 phenotypic classes with respect to either allele or genotype frequencies. However, when we tested for nonallelic associations (linkage disequilibrium), we found that of the 120 multilocus comparisons, 16 deviated significantly from random in the hypertensive class, but there were no significant deviations in the normotensive group. These findings suggest that genetic interactions between multiple loci rather than variants of a single gene underlie the genetic basis of hypertension in our study subjects. We hypothesize that such interactions may account for the inconsistent findings in previous studies because, unlike our study, prior studies almost always examined single-locus effects and did not consider the effects of variation at other potentially interacting loci.

Correlation of bcl-2 oncoprotein immunohistochemical expression with proliferation index and histopathologic parameters in colorectal neoplasia

Thebcl-2oncogene plays an important role in carcinogenesis by inhibiting cell death (apoptosis). It was initially discovered in follicular B cell lymphoma with t(14,18), and subsequently found in other malignant and premalignant lesions. Alteration of the normal controls of cell proliferation is also a significant factor in the multistep process of tumorigenesis. The proliferative activity of a given lesion is commonly valuated by MIB1, a monoclonal antibody to Ki67 proliferation antigen. Immuno-histochemical (IHC) staining expression of bcl-2 and Ki67 was retrospectively investigated in a series of 52 colorectal carcinomas and 56 adenomas according to the avidin-biotin-complex method. The aim of the study was twofold: 1) to investigate any correlation between MIB1 and bcl-2 immunostaining expression in colonic adenomas and carcinomas, 2) to identify any relationship between either marker and several histopathologic parameters including tumor size, pathologic stage, lymph node metastasis, angio-lymphatic invasion, tumor grade and differentiation in colon carcinomas. Bcl-2 was consistently higher in adenomas than in carcinomas. There were 44/56 (78.6%) adenomas, and 27/52 (51.9%) carcinomas positive for bcl-2 (p=0.004). The mean Ki67 labeling index (LI) was 30.05+/-7.6 and 38.12+/-11.01 in adenomas and carcinomas, respectively (p=0.0001). Expression of bcl-2 in carcinoma was significantly associated with a lower mean Ki67 LI and with favorable histopathologic parameters. We conclude that bcl-2 oncoprotein expression is probably an early step in the process of colon carcinogenesis, and its expression may be associated with a favorable clinical course. Furthermore, an inverse relationship exists between bcl-2 and Ki67 in colonic neoplasia. Evaluation of bcl-2 and Ki67 IHC expression in colonic carcinoma should be performed prospectively to determine if their expression is of value in predicting the clinical course in these patients.

Cortical deficits in multiple sclerosis on the basis of subcortical lesions

Patients suffering from multiple sclerosis have a high frequency of cognitive deficits usually attributable to demyelination and axonal loss in the subcortical white matter. Neurologic abnormalities referable to cortical function are uncommon but have been described. The present study describes three patients with clinically definite MS with deficits in cognitive function referable to cortical location. Two of the patients underwent positron emission tomography and showed profound cortical hypometabolism adjacent to subcortical white matter lesions seen on MRI. This paper points out that neurologic deficits referable to cortical sites may be caused by subcortical white matter lesions and that cognitive dysfunction in patients with MS may progress rapidly in the absence of motoria deficits or other evidence of clinical deterioration. Multiple Sclerosis (2000) 6 50 - 55

A direct comparison of cytolytic T-lymphocyte responses to Melan-A peptides in vitro: differential immunogenicity of Melan-A27-35 and Melan-A26-35

In this study we directly compared the in vitro responses of T-cells from normal donors and melanoma patients to Melan-A27-35 and Melan-A26-35. These peptides have been previously used in peptide-based vaccination studies. Following three stimulations with peptide-pulsed antigen-presenting cells in vitro, Melan-A-specific cytolytic T-lymphocytes (CTLs) were generated from seven of 20 subjects; two of the seven subjects responded reproducibly to both Melan-A27-35 and Melan-A26-35, three to only Melan-A27-35 and two to only Melan-A26-35. However, CTLs generated with either Melan-A27-35 or Melan-A26-35 showed cross recognition, and both types of CTL could recognize naturally processed antigen displayed on HLA-A2+ tumour cells. Furthermore, Melan-A-specific CTLs could also be generated by stimulating peripheral blood mononuclear cells with autologous melanoma cells. Our results suggest that some subjects may have a bias in their CTL repertoire which favours the generation of Melan-A27-35 specific CTLs, while others may favour Melan-A26-35 specific CTLs. It is also likely that CTL precursors capable of detecting both peptides may have different affinities to the two Melan-A peptides. Since it is difficult to predict the CTL responses to Melan-A peptide in a given individual, we suggest vaccinating with both Melan-A27-35 and Melan-A26-35 peptides in clinical trials.

Depression in young people. A growing challenge for primary care

BACKGROUND

Recent research indicates that 27% of young people aged 18-24 have a mental health problem involving mood, anxiety, personality and/or substance abuse disorders and 15-40% report depressive symptomatology. A proportion of these young people will suicide. The morbidity associated with depressive illness in this age group is high, with those experiencing a depressive episode having reduced vocational and life prospects and being highly vulnerable to further episodes in later life.

OBJECTIVE

To outline the clinical features of depression in young people and to provide strategies for appropriate management.

DISCUSSION

Presentation of depression in young people is likely to vary from accepted diagnostic criteria with non specific symptoms such as boredom, anxiety, failing adjustment and sleep disturbance predominating. Management includes attending to key social problems, ensuring a safe environment and counselling, which may be supportive counselling or more specific treatments of cognitive behavioural therapy or interpersonal psychotherapy. Medication is indicated for more severe depression or with failure of response to psychological strategies. Early case identification and intensive treatment of first episodes of depression is important in reducing prevalence, cost and morbidity.

Transscleral diode laser in the treatment of retinopathy of prematurity

PURPOSE

To assess the outcome of contact transscleral diode laser (TSDL) in the treatment of threshold retinopathy of prematurity (ROP).

METHOD

TSDL was performed in 14 eyes of 8 babies who presented to the paediatric ophthalmic service at King's College Hospital between 1996 and 1997 with threshold ROP (median post-conceptual age 26 + 1 weeks, median birthweight 835 g) by a single surgeon. Follow-up ranged from 9 to 41 weeks (median 21 weeks).

RESULTS

In 11 eyes (79%) regression of ROP occurred after a single laser treatment with a good anatomical outcome. In 3 eyes (21%) there was an unfavourable response with the development of traction retinal detachment. These include both eyes of one baby who rapidly progressed to stage IV ROP. One other eye developed a fibrotic band a few months after treatment. No significant complications of laser treatment were observed.

CONCLUSION

These initial results indicate that TSDL photocoagulation is an effective and technically straightforward alternative to cryotherapy in the treatment of ROP.

An investigation of attributional style in first-episode psychosis

OBJECTIVE

The present study investigated covert and overt attributional styles in individuals experiencing a first episode of psychosis. It was hypothesized that those individuals experiencing paranoia, as operationalized by higher scores on the suspiciousness item of the Brief Psychiatric Rating Scale (BPRS) would perform differently on both covert and overt measures of attributional style when compared to those individuals who scored lower on the BPRS suspiciousness item.

DESIGN AND METHODS

A cross-sectional design was used. The sample consisted of 62 participants (50 males and 12 females) from the Early Psychosis Prevention and Intervention Centre. The Pragmatic Inference Task (PIT) was used to measure covert attributional style, whereas the Attributional Style Questionnaire (parallel form; ASQpf) measured overt attributional style. The Rosenberg Self-Esteem Questionnaire measured global self-esteem. Participants' positive, negative, and depressive symptoms were assessed by means of the BPRS, the Scale for the Assessment of Negative Symptoms, and the Beck Depression Inventory, respectively.

RESULTS

Regression analyses found that less suspiciousness (p = .02) and more depression (p = .02) predicted higher internal attributions for negative events scores on the ASQpf. There was a trend (p = .07) for more suspicious individuals to endorse the self-serving bias (SSB) on the PIT, even despite the SSB not being large enough to be considered defensive. Verbal IQ emerged as a significant predictor of covert attributional style (p = .04).

CONCLUSIONS

The findings suggest that increasing suspiciousness does predict attributional style in the early stages of psychosis, although the relationship appears weaker than in reports with more chronic psychotic patient samples. Longitudinal research is needed to ascertain whether attributional style is a stable characteristic in psychosis, or whether it fluctuates between periods of remission and active psychosis.

The molecular basis of transferase galactosaemia in South African negroids

Transferase galactosaemia is an autosomal recessively inherited disorder caused by a deficiency of galactose-1-phosphate uridyltransferase (GALT). Manifestations include jaundice, vomiting, cataracts, mental retardation, speech abnormalities and poor growth. The GALT gene has been mapped and sequenced. The S135L mutation accounts for approximately 48% of galactosaemia alleles in African Americans and has been found to account for about 91% of galactosaemia alleles in negroid South African patients which suggested that the mutation had an African origin. We have calculated the S135L allele frequency (+/- 1SE) in a sample of healthy unrelated negroid South Africans to be 0.0067 (+/- 0.0024). The S135L mutation was also detected in negroid populations from other regions of Africa confirming its African origin.

The cost of home-based care for HIV/AIDS patients in Zimbabwe

From a study on the cost and quality of community home-based care (CHBC) for HIV/AIDS patients in Zimbabwe, programme and household costs were estimated. Interviews, using a structured questionnaire, were held with 60 patients and caregivers sampled from six types of established CHBC schemes. Detailed cost information was collected from four home care programmes, two urban and two rural. The cost of a home visit in the two urban programmes studied was estimated to be Z$129 (US$16) in one, and Z$183 (US$23) in the other. In one of the two rural schemes, the cost of a home visit was Z$313 (US$38), in the other this was Z$343 (US$42). A large proportion of these costs were not of direct benefit to the patients, as approximately 56-75% of the total cost per home visit was spent getting to the patient. The costs of a home visit in a rural home-based care programme corresponded to the costs of 2.7 inpatient days in a district hospital. The family cost of caring for a bedridden AIDS patient over a three-month period was estimated to be between Z$556-841. Caregivers spent as much as 2.5-3.5 hours a day on routine patient care. The programme costs are high, and schemes do not generally assess effectiveness, nor cost-effectiveness. The high cost of home visits leads to less frequent visits, leaving a larger part of both the burden and the cost of care to the families and the patients.

Cognitively-oriented psychotherapy for early psychosis (COPE). Preliminary results

BACKGROUND

The present study describes the results of the pilot testing of a therapy we have developed for people with first-episode psychosis. Cognitively-oriented psychotherapy for early psychosis (COPE) is aimed at facilitating the adjustment of the person, and at preventing or alleviating secondary morbidity in the wake of the first psychotic episode.

METHOD

Eighty people formed three groups: those who were offered and accepted COPE (COPE subjects); those who refused COPE (refusal subjects); and those who were offered neither COPE nor any other continuing treatment from our service (control subjects). The individuals were assessed prior to, and at the end of, COPE treatment (a 12-month period) on the Integration/Sealing Over, Explanatory Model, Scale for the Assessment of Negative Symptoms, Brief Psychiatric Rating Scale, Quality of Life, SCL-90-R, and Beck Depression Inventory measures.

RESULTS

People who received COPE obtained significantly superior scores (P < 0.05) to the control group on four of the seven measures but only significantly out-performed the refusal group on one of the seven measures (P < 0.05). The COPE group performed significantly worse on the BDI than the refusal group (P < 0.05). Effect sizes are also provided for each measure.

CONCLUSIONS

There seems to be a place for psychological therapy in this group of people but our results need to be replicated in a more definitive randomised controlled trial and such a study is now in progress.

Antigen specificity and tumour targeting efficiency of a human carcinoembryonic antigen-specific scFv and affinity-matured derivatives

We have examined the biological properties of CEA6, a human carcinoembryonic antigen (CEA)-specific single-chain Fv (scFv) isolated by phage display, and five related clones derived by affinity maturation and selected for improved off-rate (Koff). All clones bind strongly and specifically to CEA-positive human tumours by immunocytochemistry and show negligible cross-reactivity with normal colon. Flow cytometry of scFv on human liver cells indicates a shift in fine epitope specificity resulting from mutagenesis. All monomeric scFv have been radioiodinated, retaining effectively full binding activity. A single intravenous injection into nude mice bearing human colon tumour xenografts confirms tumour targeting in all cases. As reported in other studies, the kidney is the main route of elimination of scFv at early time points. Tumour binding of the parental antibody CEA6 consistently gives the highest tumour-blood ratios at 24 h (mean 16:1). Clone TO6D11, which has a sevenfold reduced Koff relative to CEA6, showed no difference in tumour uptake at 24 h but persisted at the tumour site for longer than CEA6. This study demonstrates a possible correlation between binding affinity and tumour residence time when examined in this model.

Flow cytometric apoptosis assays indicate different types of endonuclease activity in haematopoietic cells and suggest a cautionary approach to their quantitative use

Two flow cytometric apoptosis assays, the terminal deoxynucleotidyl transferase (TdT) assay and in situ nick translation (ISNT) assay, were assessed for their ability to quantitate drug-induced apoptosis in CLL lymphocytes. In contrast to HL60 cells, biotinylated dUTP could not be effectively incorporated into apoptotic CLL lymphocytes using exogenous TdT. This suggested that CLL lymphocytes possess a different type of endonuclease that cleaves DNA, leaving blunt or 3' recessed DNA breaks, which are poor substrates for TdT. This possibility was tested using lambda exonuclease, which can convert a blunt or 3' recessed DNA break into a 3' overhang. Apoptotic CLL lymphocytes pre-treated with lambda exonuclease demonstrated increased nucleotide incorporation with TdT. Single-strand DNA breaks are also present in apoptotic CLL lymphocytes, as labelled nucleotides could be incorporated using the in situ nick translation assay. This study suggests that the efficiency of tailing reactions may be limited by the nature of the endonuclease activity in certain cell types and that validation with other parameters is an essential prerequisite to their quantitative use.

The relative population sizes of megakaryocytic cells in mouse bone marrow as determined by mpl ligand responsiveness

The relative population sizes of mpl ligand-responsive megakaryocytic cells were investigated, and all megakaryocytes grown in culture were assessed. Three groups were analyzed: 1) immature cells with the ability to form single mature megakaryocytes; 2) cells with the ability to divide once before forming megakaryocytes (doublets); and 3) progenitor cells with the ability to form colonies, i.e., to undergo both cytokinesis and maturation. Immature cells forming single megakaryocytes proved most sensitive to the mpl ligand. Committed megakaryocyte progenitors required approximately 30 times more mpl ligand to achieve maximum growth than did the immature megakaryocyte population. Similar numbers of committed megakaryocyte progenitors responded to interleukin (IL)-3 and to mpl ligand. The amplification potential of these progenitor cells responding to each growth factor was assessed by measuring the number of megakaryocytes per colony. In response to mpl ligand progenitor, cells generated smaller colonies, with most cell divisions completed at a signifcantly earlier time point compared with progenitor cells responding to IL-3. The growth of more primitive megakaryocyte progenitors was best achieved in combination with other growth factors, notably IL-3; mpl ligand alone was ineffective in this regard. A novel finding was the significant number of megakaryocytes that grew in culture as closely coupled pairs (doublets). Data reported indicate that doublet formation may be a result of detection and stimulation of immature megakaryocytes rather than the diminished mpl ligand responsiveness of a proportion of megakaryocyte progenitors. By combining the number of mpl ligand-responsive cells forming single megakaryocytes with those forming megakaryocyte doublets, it is estimated that the size of the immature megakaryocyte pool greatly exceeds previous calculations. Thus we conclude that the immature megakaryocyte population is significantly larger than previously estimated and that these cells are the most sensitive to mpl ligand. Accordingly, these cells are potentially crucial in bone marrow responsiveness to mpl ligand that results from acute thrombocytopenia, being capable not only of endomitosis and maturation but perhaps of cell division as well.

Use of pulsed irrigation evacuation in the management of the neuropathic bowel

Management of the neuropathic bowel is one of the major issues in the treatment of patients with severe spinal cord injury (SCI). Pulsed irrigation evacuation (PIE) has been evaluated in several small studies for the clearing of fecal impactions in patients with a neuropathic bowel. We evaluated our experience with 398 PIE procedures performed on inpatients and outpatients at our facility. It has proven to be both safe and effective in a wide variety of patients with this disorder, and is a useful addition to traditional methods in the management of the neuropathic bowel.

Absence of intrafamilial transmission of hepatitis C in patients with inherited bleeding disorders

Hepatitis 'C' virus (HCV) infection has caused significant anxiety in patients with inherited bleeding disorders. A significant number of patients with HCV have developed chronic liver disease, cirrhosis and hepatocellular carcinoma. The exact risk of heterosexual and contact transmission is unclear at the moment. A test for antibody to hepatitis 'C' was offered, after counselling, to spouses and family members of 118 known hepatitis 'C' antibody positive patients with inherited bleeding disorders. Two hundred and fifteen family members were tested, 73 partners and 142 household contacts; all were found negative for hepatitis 'C'. Our experience confirms the low risk of heterosexual and contact transmission of hepatitis 'C' virus.

Causes of blindness in northwest Cambodia

A hospital-based study in the northwest of Cambodia identified 453 blind adults and 30 blind children seen consecutively at the provincial ophthalmic department between January and September 1994. Blindness was defined as a visual acuity of less than 3/60 in the better eye. Cataract was the cause of blindness in 266 (59%) adults, of which 15 cases (3.3%) were surgical complications. Sixty-three cases (14%) were due to glaucoma and 53 (11.5%) patients had corneal scars, of which 12 (2.5%) were due to trachoma. Bilateral trauma, usually due to landmine injuries, accounted for 17 patients (4%). Of the 30 blind children, corneal scarring accounted for 12 cases (40%), congenital causes for 14 (47%) and optic atrophy secondary to meningitis for 4 (13%). There is at present an inadequate ophthalmological service for the vast majority of people living outside the capital Phnom Penh. These hospital-based data suggest that there is a need to train general doctors to surgically manage patients with visual loss from cataract and glaucoma, which together account for 70% of all cases of blindness, and highlight the need for a large population-based survey.

Covert poisoning with difenacoum: clinical and toxicological observations

1. The coumarin anticoagulant difenacoum was detected by high performance liquid chromatography (HPLC) with multi-wavelength UV detection in plasma from a 41 years old man who presented with a severe deficiency of vitamin K-dependent clotting factors of unknown aetiology. A longitudinal toxicological study of the consequent coagulopathy is described. 2. Plasma concentrations of difenacoum declined from 0.97 to 0.11 mgl-1 in 47 days with a terminal half life of 11.7 days. Rifampacin (300 mg bd) had no apparent effect on the terminal half life of the drug. Subsequently plasma concentrations of difenacoum and descarboxyprothrombin (DCP) unexpectedly increased. 3. Seven months after exposure clotting times were prolonged. The patient continued to have episodes of epistaxis, haematoma, purpurae and bruising and he required frequent treatment with Fresh Frozen Plasma in additional to oral phylloquinone (200 mg day-1). 4. Intermittent and unexpected increases in plasma concentrations of difenacoum and descarboxypro-thrombin suggested that covert, repeated ingestion of the anticoagulant was the most likely cause of the poisoning. The measurement of low concentrations of plasma phylloquinone except following supervised ingestion of the vitamin indicated that as an outpatient, the subject was not compliant with treatment despite his protestations to the contrary. He continued to deny this even when confronted by laboratory findings and at no time did he ever admit to self-poisoning.

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.