Marfan syndrome caused by a mutation in FBN1 that gives rise to cryptic splicing and a 33 nucleotide insertion in the coding sequence

We have studied a patient with Marfan syndrome whose mutation was not detected by heteroduplex analysis. Primary cultured patient fibroblasts were metabolically labelled and found to secrete fibrillin-1 defectively when compared with an age-matched control. Sequencing of patient cDNA, isolated by reverse transcription-polymerase chain reaction of patient fibroblast RNA, detected a 33-bp insertion. The reading frame of the mutant allele was maintained and predicted the insertion of 11 amino acids at the beginning of calcium-binding epidermal growth factor-like domain 29. Direct sequencing of genomic DNA detected a heterozygous G+1-->A transversion in intron 46 of FBN1. The 11 amino acid insertion was the consequence of the usage of a cryptic splice site 33-bp downstream of the mutation. This is the first reported case of a splicing defect in FBN1 leading to the production of a full-length fibrillin-1 transcript containing a large amino acid insertion.

The effects of sediment-associated triorganotin compounds on the gills of the European flounder, Platichthys flesus (L.)

The effects of exposure to sediment-associated tri-n-butyltin chloride (TBT) and triphenyltin chloride (TPhT) were examined in the euryhaline European flounder, Platichthys flesus (L.). The effects were quantified by measuring the changes in sodium efflux, Na(+)/K(+)-ATPase activity and the numbers, areas and distribution of chloride cells in the gills of freshwater-adapted fish, following a rapid transfer to seawater. After transfer, the Na(+)/K(+)-ATPase activity and the sodium efflux significantly increased in both the TPhT and control groups but not in the TBT group. However, Na(+)/K(+)-ATPase activity and the sodium efflux in the TPhT group had returned to pre-salinity transfer levels by day 15 after the initial exposure to TPhT. Morphological changes in the numbers and areas of chloride cells, known to be associated with seawater adaptation, took place in the control group, i.e. there was a significant reduction in the number of lamellar chloride cells accompanied by an increase in the number of interlamellar chloride cells. There was a reduction in the numbers of lamellar chloride cells in the TBT-exposed group following transfer to seawater but the mean number was significantly higher than the control group by the end of the experiment. In the TPhT-exposed group, the reduction was not significantly different to that seen in the control group. By the end of the experiment, both organotin-exposed groups had significantly lower mean numbers of interlamellar chloride cells than the control group. Before transfer to seawater, the mean areas of lamellar and interlamellar chloride cells of all three groups were not significantly different. On transfer, the mean areas of lamellar chloride cells in the control group became significantly smaller than the mean areas of the organotin groups. There was no significant difference in the mean areas of interlamellar chloride cells in the control and TBT groups between the start and finish of the experiment but there was a significant increase in the mean area of TPhT-treated animals at the end of the experiment when compared to the control group. The results presented in this study lead to the conclusion that tri-n-butyltin chloride and triphenyltin chloride in sediments are capable of significantly disrupting both the physiological as well as morphological components of ionic regulatory functions of an estuarine fish, at concentrations currently found in estuarine sediments.

Partner notification in HIV-1 infection: a population based evaluation of process and outcomes in Scotland

OBJECTIVES

To evaluate the process and outcomes of HIV partner notification (PN) activity in Scotland.

DESIGN

Retrospective population based study.

SUBJECTS

114 adults newly diagnosed with HIV infection (index patients) in Scotland between September 1995 and August 1996.

SETTING

Healthcare settings in which all 114 new HIV diagnoses were made: 42 (37%) from genitourinary medicine; 32 (28%) infectious diseases; 18 (16%) general practice; and 22 (19%) from other sites.

MAIN OUTCOME MEASURES

Number of partners notified and tested up to 9 months after initial diagnosis.

RESULTS

Of 114 index patients (IPs), information on current partners was available for 102 (89%). PN was not appropriate for 47 of the 102 IPs. The remaining 55 IPs identified 63 current partners at risk, of whom 51 were notified: 44 underwent HIV testing, which yielded 11 new HIV positive diagnoses. Information on previous partners was available for only 56 IPs (49%). PN was not appropriate for 30 of the 56 IPs; the remaining 26 IPs identified 46 previous partners at risk, of whom 12 were notified: four were tested, but yielded no new diagnoses.

CONCLUSIONS

Notification of current partners was performed well and was an effective strategy for identification of HIV positive individuals at a presymptomatic stage. Notification of previous partners was limited. Partner notification was attempted in a wide range of healthcare settings. Given the clinical effectiveness of antiretroviral therapy, partner notification as a tool towards early diagnosis of HIV disease deserves renewed attention.

Hepatitis C virus among high and low risk pregnant women in Dundee: unlinked anonymous testing

OBJECTIVE

To determine the prevalence of the hepatitis C virus among pregnant women, to gauge the non-injecting, particularly sexual, risk of them being hepatitis C virus infected and to assess the potential impact of selective antenatal screening.

POPULATION

Antenatal clinic attenders and women undergoing termination of pregnancy in 1997.

SETTING

Ninewells Hospital, Dundee.

DESIGN

Unlinked anonymous hepatitis C virus antibody testing of residual sera from specimens sent to the virus laboratory for routine serological testing. The results were linked to non-identifying risk information.

RESULTS

Overall anti-hepatitis C virus prevalence was 0.6% (23/3,548). Prevalences among injecting drug users, non-injectors who had a sexual partner who injected, and those with neither risk respectively were 41% (7/17), 15% (5/33) and 0.3% (11/3,498). Relative risks for being an injector and a sexual partner of an injector respectively were 131 (95% CI 58-297) and 48 (95% CI 5-32). It is estimated that one of the 18 antenatal clinic attenders gave birth to an infected child.

CONCLUSION

Findings suggest that non-injecting partners of injectors may be at considerable risk of acquiring hepatitis C virus sexually. Efforts to promote the use of condoms among injectors and their sexual partners should be increased. Selective anti-hepatitis C virus screening of women who reported high risk behaviour would have failed to detect half the cases. Research to gauge the views of women of childbearing age on anti-hepatitis C virus testing is required.

A retrospective review of pregnancy outcome after misoprostol (prostaglandin E1) induction of labour

This retrospective study looked at the outcome of using 50-100 micrograms misoprostol once daily to induce labour compared to the outcome of the overall patient population delivered during the same period (1994-1996). During that period 11,255 patients were delivered and 1037 (9.2%) were induced with misoprostol. Results showed a significantly lower mean Caesarean section rate: 9.3% for the misoprostol group versus 13.3% for the overall population (p = 0.002, Odds Ratio (OR) 0.67, 95% CI 0.53, 0.83). The abruption rates were not significantly different: 0.8% for misoprostol versus 0.4% (p = 0.09, OR 1.86, 95% CI 0.81, 4.09). There was more postpartum haemorrhage in the misoprostol group: 5.6% versus 3.5% (p = 0.0006, OR 1.63, 95% CI 1.22, 2.19); a higher incidence of Apgar scores less than 6 at one minute 10.2% versus 7.9% (p = 0.0093, OR 1.33, CI 1.06, 1.65) but not at five minutes 2.9% versus 2.4% (p = 0.674, OR 1.09, CI 0.73, 1.61) and a higher perinatal mortality rate 55/1000 versus 16.3/1000 (p = 0.00, OR 3.5, 95% CI 2.55, 4.80). The rate remained higher but not significantly so when a correction was made to eliminate the high number of intrauterine deaths induced with misoprostol 18/1000 versus 16.3/1000 (p = 0.69, OR 1.11, 95% CI 0.66, 1.84). There were no cases of uterine rupture in either group. In conclusion, there was a significantly lower Caesarean section rate among patients who had once daily misoprostol induction of labour. Close monitoring of the foetus, in patients with misoprostol induction, is needed to detect foetal distress and prophylaxis against postpartum haemorrhage is still mandatory.

Prevalence of antibodies to hepatitis C virus, HIV and human T-cell leukaemia/lymphoma viruses in injecting drug users in Tayside, Scotland, 1993-7

The prevalence of blood-borne viruses in injecting drug users (IDUs) in Tayside, Scotland was determined by testing serum samples from IDUs who underwent attributable HIV antibody testing during 1993-7. The prevalence of antibodies to HIV was 29/802, (3.6%); to hepatitis C virus (HCV) 451/691, (65.3%); and to human T-cell leukaemia/lymphoma viruses type 1 and 2 (HTLV) 0/679, (0.0%). The prevalence of HIV and HCV antibodies were higher in subjects over the age of 25 (P = 0.03 and P = 0.001, respectively). During 1993-7 the prevalence of HCV fell only in younger female IDUs (P < 0.01). HIV prevalence has declined dramatically since 1985, when a rate of 40% was recorded in similar populations. Harm reduction measures have failed to control HCV the spread of infection among IDUs in Tayside, as indicated by the high proportion of antibody positive IDUs, particularly males under the age of 25. Future studies should address the nature and effective reduction of continuing risk taking among IDUs in Tayside.

Response of haemocyte lysosomes to bacterial inoculation in the oysters Ostrea edulis L. and Crassostrea gigas (Thunberg) and the scallop Pecten maximus (L)

Data are presented that demonstrate the application of the neutral red retention assay (NRR) to monitor the effects of a bacterial inoculation on the haemocyte lysosomes of the European flat oyster Ostrea edulis, Pacific oyster Crassostrea gigas and scallop Pecten maximus. Bivalves were acclimated to three temperature regimes (5, 15 and 25 degrees C), at constant salinity for 7 days in the laboratory. Once baseline responses to acclimation temperature had been established, the effects of an in vivo inoculation on haemocyte lysosomal stability were assessed using the NRR assay. Lysosomal membrane stability was reduced in the presence of bacteria for all three species of bivalve, but destabilisation of C. gigas haemocyte lysosomes appeared to be most sensitive to the presence of the bacterium Listonella anguillarum. For all three bivalve species, the reduction in lysosomal stability appeared to be proportional to the growth of the bacterial inoculate. Using appropriate controls, the NRR assay was demonstrated to have great potential as a tool with which to make rapid initial assessments of the immune status of bivalve molluscs.

Organotin and osmoregulation: quantifying the effects of environmental concentrations of sediment-associated TBT and TPhT on the freshwater-adapted European flounder, Platichthys flesus (L.)

Chronic (5 weeks) exposure of freshwater-adapted European flounder, Platichthys flesus (L.), to environmental concentrations of sediment-associated tri-n-butyltin chloride (TBTCl) and triphenyltin chloride (TPhTCl) caused significant changes to hydromineral fluxes and membrane permeability, mechanisms that maintain osmotic homeostasis. The half-time of exchange of tritiated water (THO) in TBTCl- and TPhTCl-exposed fish was significantly increased during the first 2 weeks of the experiment and then decreased steadily, eventually reaching the level that the control group had constantly maintained throughout the experiment. This change in apparent water permeability was accompanied by a significant decrease in diffusional water flux across the membranes. Passive Na(+)-efflux across the gills was increased significantly but effluxes in the control group were near constant over the same time span. Drinking rates in the organotin groups increased significantly while the rate of urine production did not change. This lead to an increased net water balance in the organotin groups and consequently to a significant reduction of the blood osmolality of both organotin groups when compared to a control. There would appear to be a metabolic cost attached to the changes produced by exposure to environmental levels of organotin compounds which are manifested as a minimal increase in body length compared to the controls.

Working patterns of trainee anaesthetists in the UK: results of a national postal survey

The 'New Deal' restrictions on junior doctors' hours have major implications for the staffing of anaesthetic departments and the provision of adequate training. The results of a national postal survey demonstrate a decline in traditional on-call arrangements, especially in hard-pressed work sectors such as intensive care. A substantial number of anaesthetic departments have still completely to satisfy the hours restrictions in many work sectors. Many departments experience recruitment difficulties and express concern about both service and training issues.

Products for Alzheimer's self-stimulatory wanderers

The objective of this study was to develop a variety of sensory stimulation products for the behavioral intervention of patients with Alzheimer's type dementia. Many caregivers have relied on physical and chemical restraints as the primary method of patient intervention due to the lack of appropriate dementia management products. This significantly lowers the sufferer's quality of care and life. As the age group most susceptible to Alzheimer's disease (65 and older) is the fastest growing segment of our society, an appropriate care solution must be sought. The specific aim of this study was to develop products that are sensory satisfying for the Alzheimer's patient that exhibits self-stimulatory wandering behavior. Sensory satisfying objects for product development would be determined through structured observations of self-stimulatory wanderers in an institutionalized setting. Variations of product design and mounting would be pursued in order to develop products that are not only safe and effective for patient use, but are easy for the caregiver to implement and maintain. Such products would have widespread commercial application in both the institutional and private care settings such as nursing homes, adult day care facilities, Alzheimer's care facilities, convalescent homes, mental health institutions, and assisted-living facilities.

Contemporary trends and practice strategies in pediatric occupational and physical therapy

This paper identifies and reflects on recent trends in pediatric occupational therapy and physical therapy practice. These trends were initially identified by the student authors for a Maternal and Child Health (MCH) leadership seminar, which was conducted as part of the postprofessional graduate program in physical therapy at the University of Washington. Trends were then reviewed and discussed among the student and faculty authors. Consensus was reached on the most important trends, which were subsequently summarized in this paper. The first part of the paper reviews the impact of these trends on current and future clinical practices in health, educational, and community-based settings. The second part of the paper offers proposed directions to meet the challenges presented by the trends in four key areas; (1) research, (2) professional education, (3) enhancing family-centered care, and (4) advocacy.

The use of herbal teas and remedies in Jamaica

We investigated the prevalence of the use of herbs among adults and children in Jamaica in 1996. Two concurrent surveys were conducted in randomly selected urban and rural areas: among adults and among caretakers of young children. From over 90% of the selected households, all caretakers of children under 6 years and one randomly selected adult (18 years or older) were interviewed using structured questionnaires. The 457 adults reportedly used 156 types of herbs: a mean of 6 +/- 3 (mean +/- standard deviation) by the urban adults, and 10 +/- 6 by the rural adults (t-test, p < 0.001). Almost 100% of respondents had at some time used herbs for teas or for treating illnesses. The most common method of preparation was by infusion or boiling in water, then adding sugar. Urban respondents, women and those who were employed were more likely to buy medicines than to use herbal remedies. One hundred and sixty-seven caretakers of 203 children under 6 years were interviewed. The mean number of herbs given to each child was between 2 and 3. The most common herbs were introduced within the first 6 months of life. Many caretaker factors were associated with herbal use. Public health implications include the potential toxicity of some herbs, the possibility that herbal teas given to young children may displace more nutritious foods and delay presentation to health care facilities. The findings will allow policy makers to target those most likely to use herbal preparations or to give them to young children, and target herbs to be analyzed for toxic or beneficial properties.

The effects of salinity on the interaction between a pathogen (Listonella anguillarum) and components of a host (Ostrea edulis) immune system

Data are presented from a study to determine how salinity may modulate the interactions between an opportunistic bacterial pathogen Listonella anguillarum and the immune system of a bivalve host, the European flat oyster Ostrea edulis. Oysters were acclimated to three salinity regimes (32, 25 and 16%, at 15 degrees C) for 7 days within the laboratory and were then inoculated with a sub-lethal dose of live L. anguillarum. Forty-eight hours after inoculation measurements were made of the changes in haemocyte composition, haemolymph hydrogen peroxide concentration and haemolymph lysozyme activity to provide information on both the cellular and humoral components of the immune system. The data indicated that in the majority of cases the effects on the immune system were dose dependent. At 32%, a salinity which promoted the growth of the bacterial inoculate, there was a significant increase in the number of circulating large granulocytes and a significant decrease in the haemolymph hydrogen peroxide concentration. At lower salinities, which were less favourable to the growth of L. anguillarum, there were no significant immune system effects. The data highlight the potential for environment management as a tool in controlling opportunistic pathogens and subsequently disease in commercially important bivalve species.

Segmentation of the skull in MRI volumes using deformable model and taking the partial volume effect into account

Segmentation of the skull in medical imagery is an important stage in applications that require the construction of realistic models of the head. Such models are used, for example, to simulate the behavior of electro-magnetic fields in the head and to model the electrical activity of the cortex in EEG and MEG data. In this paper, we present a new approach for segmenting regions of bone in MRI volumes using deformable models. Our method takes into account the partial volume effects that occur with MRI data, thus permitting a precise segmentation of these bone regions. At each iteration of the propagation of the model, partial volume is estimated in a narrow band around the deformable model. Our segmentation method begins with a pre-segmentation stage, in which a preliminary segmentation of the skull is constructed using a region-growing method. The surface that bounds the pre-segmented skull region offers an automatic 3D initialization of the deformable model. This surface is then propagated (in 3D) in the direction of its normal. This propagation is achieved using level set method, thus permitting changes to occur in the topology of the surface as it evolves, an essential capability for our problem. The speed at which the surface evolves is a function of the estimated partial volume. This provides a sub-voxel accuracy in the resulting segmentation.

Prevalence of hepatitis C virus infection among injecting drug users in Glasgow 1990-1996: are current harm reduction strategies working?

OBJECTIVES

To determine the prevalence of HCV antibodies among injecting drug users and to gauge the effectiveness of needle/syringe exchange in preventing the transmission of HCV infection.

METHODS

Between 1990-1994 and in 1996, annual cross-sectional surveys of injecting drug users in Glasgow were conducted. In order to ensure as representative a sample as possible, the 1949 respondents were recruited from both 'in-treatment' and 'out-of treatment' settings. Injectors were interviewed about their risk behaviours for blood-borne viruses and provided a saliva sample which was initially tested, anonymously, for HIV antibodies, and subsequently tested for hepatitis C infection.

RESULTS

Among 1949 injectors, the prevalence of salivary antibodies, indicative of hepatitis C viraemia, was 61%(95%, confidence interval (CI) 59%-63%): the estimated prevalence of serum antibody positivity was 72%. Length of injecting, year of commencing drug injecting and the number of times in prison were predictive of antibody positivity. Thirty-one per cent of injectors who commenced their injecting after 1992, following the full establishment of needle/syringe exchange in the city, were salivary antibody positive, and the majority of their infections were acquired outside the prison setting. Respondents who began injecting after the introduction of needle/syringe exchange in the city were significantly less likely to test HCV antibody positive than those who commenced injecting prior to the advent of needle/syringe exchange, after adjusting for length of injecting career.

CONCLUSION

The prevalence of HCV among injectors in Glasgow has decreased during the era of needle/syringe exchange. However, there is evidence to suggest that the incidence of infection remains high. Since the prevalence of hepatitis C viraemia among the city's injecting population is extremely high, ongoing transmission is inevitable unless more effective interventions are identified and implemented urgently.

Risk of HIV transmission from patients to surgeons in the era of post-exposure prophylaxis

The HIV prevalence, among patients either undergoing, or with the potential to undergo, surgery were estimated using data from unlinked anonymous HIV surveys of patients in Glasgow hospitals during 1992-1997 in order to quantify the risk of surgeons acquiring HIV occupationally in the era of post-exposure prophylaxis (PEP) availability. A range of prevalence rates was applied to data on other factors influencing risk; these comprised, i) the probability of a percutaneous injury from a sharp instrument used on an HIV infected patient resulting in HIV transmission, ii) the number of injuries sustained and iii) whether or not PEP was administered. On the basis of, for example, a surgeon sustaining three percutaneous injuries over 12 months and not taking PEP after each, the annual risks ranged from 1 in 2,000,000 for urological/renal surgeons to 1 in 200,000 for those performing general surgery/ENT/gynaecological procedures. The administration of PEP after each injury would reduce these rates to 1 in 10,000,000 and 1 in 1,000,000 respectively. The risk of surgeons acquiring HIV occupationally in a city which has an HIV prevalence typical of most urban areas in the UK, is 'minimal' or 'negligible'. In the context of such low risk and our limited knowledge of the adverse effects of PEP, the risk assessment to decide whether or not to give PEP should be well informed and consistent. Current guidelines to help physicians and affected healthcare workers in their decision making need to be improved.

Characterisation of fibrillin-1 cDNA clones in a human fibroblast cell line that assembles microfibrils

Fibrillin-1 is a large extracellular glycoprotein which is a major structural component of 10-12 nm microfibrils. Defects in human fibrillin-1 give rise to the autosomal dominant connective tissue disease the Marfan syndrome and related disorders. Previous studies examining the biosynthesis and secretion of recombinant fibrillin-1 fragments have been performed in cell lines which do not assemble fibrillin into extracellular 10-12 nm microfibrils. Conflicting data have been obtained regarding N-terminal processing. In this study we have characterised a human fibroblast cell line MSU-1.1 which shows a similar endogenous fibrillin-1 pulse chase profile to primary human dermal fibroblasts and produces microfibrils. Expression of a approximately 50 kDa N-terminal recombinant peptide in MSU-1.1 resulted in efficient secretion of this peptide into conditioned media, N-terminal sequence analysis of the purified peptide identified 2 protease cleavage sites and a presumed signal peptidase site. Together these data identify the natural leader sequence of fibrillin-1 and the presence of two processing sites in the N-terminus of fibrillin-1. The identification of an N-terminal processing site in recombinant fibrillin-1 similar to that obtained in a previous study which used an HT1080 fibrosarcoma host cell line excludes defective N-terminal processing as the cause of the assembly defect in this cell line. A full length normal and mutant fibrillin cDNA (approximately 8.6 kb) was constructed and stable integration of each into MSU1.1 led to RNA transcription at approximately 5% of endogenous levels. This is the first report of transcription from the full length fibrillin-1 cDNA. The low levels of transcription achieved, suggest that additional upstream and downstream DNA sequence elements will be required for high levels of full length fibrillin-1 cDNA expression.

Molecular analysis of eight mutations in FBN1

Mutations in the gene encoding extracellular glycoprotein fibrillin-1 (FBN1) cause Marfan syndrome (MFS) and other related connective tissue disorders. In this study, eight mutations have been detected in MFS patients by heteroduplex analysis. These comprise two missense mutations, C1835Y and C2258Y in calcium-binding epidermal growth factor-like domains, two nonsense mutations, R1541X and R2394X in transforming growth factor beta1-binding protein-like domains, one splice site mutation, which has been detected previously, and three small insertions or deletions resulting in a frameshift. Fibroblast cells have been established from seven of the MFS patients and the biochemical effects of the mutations on fibrillin-1 synthesis and secretion assessed by pulse-chase analysis. Each cysteine mutation resulted in the delayed secretion of fibrillin-1 and both nonsense and frameshift mutations caused reduced levels of synthesis and/or deposition of fibrillin-1. Indirect immunofluorescence and rotary shadowing electron microscopy analysis of fibrillin microfibrils revealed no major differences between normal and patient samples. We discuss the relative merits of the biochemical techniques used in this study.

Monitoring cytomegalovirus retinitis prevalence in an HIV-seropositive cohort: the assessment of improvements observed following the introduction of highly active antiretroviral triple therapy

This paper concerns the ophthalmic assessment of patients with acquired immunodeficiency syndrome (AIDS) for a number of eye conditions and in particular cytomegalovirus (CMV) retinitis. CMV has been the most common opportunistic infection associated with AIDS and the leading cause of blindness among AIDS patients. There have been early indications of a widespread fall in CMV prevalence internationally following the introduction of a new highly active antiretroviral triple (HAART) therapy. Our study sought to assess the position for Ireland. Our cohort was the entire population of stage IV AIDS patients attending the country's leading referral centre. The total number of patients examined was 167 and the period of examination was 1 May 1995 to 30 April 1997. HAART was introduced in March 1996, so the data permitted a 'before and after' comparison of various clinical findings. The incidence of new CMV cases was found to be 4 among the 102 patients examined in the first 12-month period and one among 107 patients examined in the second 12-month period. There were accompanying declines in HIV-related noninfectious retinal vasculopathy (HIVR), keratitis and other conditions. The findings are promising, but we argue that caution is needed in assessing long-term trends. In the paper we discuss a number of methodological issues in the collection and analysis of the clinical data and in the interpretation of results.