Follow up of workers previously exposed to silver solder containing cadmium

OBJECTIVES

To study longitudinal biological monitoring data on urinary and blood cadmium collected in a small cohort of nine workers who had been brazing for several years with solders containing cadmium.

METHODS

Cadmium was measured by neutron activation analysis in livers and kidneys, and estimates of renal function were carried out in 1983 and 1995. During the intervening period exposure to cadmium was dramatically reduced by local exhaust ventilation control and substitution of the solder containing cadmium.

RESULTS

From urinary protein measurements there was evidence within the group of increasing renal tubular damage over the 12 year period, even though exposure to cadmium was dramatically reduced over this period and almost eliminated by 1995. There was no evidence from serum creatinine of decreasing glomerular filtration rate, and the renal tubular handling of calcium, phosphate, or urate had not worsened significantly. Blood and urinary cadmium concentrations reduced significantly over the 12 year period but were still substantial in 1995. Blood cadmium concentrations tended to reflect cadmium body burden in 1995 when exposure had been low for several years, and decreased most significantly during 1983-90. By contrast urinary cadmium concentrations only decreased significantly from about 1990 onwards. Urinary cadmium was not significantly correlated with liver or kidney cadmium concentration in either 1983 or 1995. This may be due to the level of tubular dysfunction in the cohort. Calculated cumulative excretion of cadmium over the 12 year period was substantially greater than the loss of cadmium measured in livers and kidneys and the derived loss in body burden. Reasons for this are discussed. It is possible that in cohorts, where renal damage is apparent, urinary concentrations reflect a substantial component of current exposure rather than stored body losses.

CONCLUSIONS

The data reinforce the concept that blood cadmium concentrations may not always reflect recent exposure, but may reflect body burden derived from historical exposure depending on the degree of current exposure; and that the decline in urinary and blood cadmium measurements after removal from, or reduction in, exposure will be slow and depend on the historical body burden.

Locum doctors in general practice: motivation and experiences

BACKGROUND

There is evidence of dissatisfaction with locum doctors' performance, but little is known about doctors who work as locums in general practice or about their experiences of this work.

AIM

To describe the motivations and experiences of doctors providing locum cover in general practices.

METHOD

A postal questionnaire survey distributed to locums through organizations such as locum groups, commercial agencies, and general practices.

RESULTS

Questionnaires were returned by 111 doctors currently working as locums in general practice. Four main reasons for working as a locum GP were: as a short-term option while between posts, to gain experience of different practices before commitment to one practice, to balance work and family or other commitments, to continue part-time work after retirement. One-quarter of responders intended to continue working as a locum indefinitely. The drawbacks of locum work included frustration with low status, lack of security, and difficulty accessing structured training and education.

CONCLUSION

Locum doctors in general practice are a heterogeneous group that includes those who have chosen this type of work. The doctors who intend to continue as locums indefinitely represent a useful resource in primary care whose ability to provide short-term cover could be maximized. The need to control the quality of 'freelance' doctors should not overshadow the need to control the quality of their working environments.

Chemical labyrinthectomy and cochlear implantation for Menière's disease--an effective treatment or a last resort?

The surgical management of Menière's disease presents a difficult and controversial problem and includes various procedures ranging from 'placebo operations' to vestibular nerve section. The situation is even more complex in the case where the only hearing ear is affected. We present a case of severe debilitating vertigo due to Menière's disease that was treated by chemical labyrinthectomy and cochlear implantation. This unique management strategy allowed restoration of useful hearing and relief of vertigo.

The use of regenerable, affinity ligand-based surfaces for immunosensor applications

The regeneration of antibody-binding surfaces is of major importance for re-usable sensor formats such as required for direct 'real-time' biosensing technologies and is often difficult to achieve. Antibodies commonly bind the antigen with high avidity and may themselves be sensitive to regeneration conditions. The interaction of polyclonal anti-chlorpyriphos antibody with an immobilised chlorpyriphos-ovalbumin (chlor-oval) conjugate and the interaction of soluble recombinant CD4 with covalently immobilised anti-CD4 IgG are presented in order to highlight these difficulties. Affinity-capture is suggested as an alternative format as it facilitates surface regeneration, directed immobilisation and the attainment of interaction progress curves that conform to the ideal pseudo-first-order kinetic interaction model. Protein A, protein G and polyclonal anti-mouse Fe-coated surfaces were used to observe the interaction of captured anti-GST monoclonal antibody with glutathione-s-transferase (GST). It was shown that a protein A affinity-capture surface produced ideal interaction progress curves while both protein G and polyclonal anti-mouse Fe resulted in systemic deviations.

Promoting self-care in epilepsy: the views of patients on the advice they had received from specialists, family doctors and an epilepsy nurse

The aim of the study was to examine patients' satisfaction with information and advice on epilepsy and self-care provided by medical specialists, general practitioners and a special nurse. We interviewed patients following a trial of nurse-run clinics for epilepsy in general practice. 44 patients, two-thirds of whom had at least one epilepsy attack in the prior 6 months were seen in their homes in the south of England. A recurring theme from interview data was that patients perceived the doctors' time as too limited to explain the condition and how to manage it, whilst the nurse had the time and expertise to do so. Overall the nurse trained in epilepsy care was valued highly for providing advice and support, especially in explaining the social aspects of epilepsy. Patients expressed the belief that they would have benefited most by seeing a special nurse at the time when epilepsy was first diagnosed.

Developmental stages and spiritual coping responses among economically impoverished women living with HIV disease

Identifies environmental markers, situational appraisals, perceived ability to mediate situations and outcomes, primary coping strategies, and purposes served by religion and spirituality in 10 HIV-positive women recruited from a regional health care clinic. Findings indicated that the women experienced a disintegration of family during their early developmental years, yielding feelings of hopelessness and isolation; that their sexual development was marked by rape and incest, and their early adulthood was characterized by failed relationships, pregnancies, drugs, and alcohol. Reports that the women's religious influences were predominantly maternal and provided a model for intercessory prayer. Notes that prior to their diagnosis of HIV, participants described their coping as escapist, while after diagnosis they believed there was a divine intercession renewing their spiritual growth and connectedness with others. Reports that the women's personal spirituality was greatly influenced by prayer, television ministries, and reading the Bible. Suggests the interventions that actively recruit women into social support services, health care systems, and faith congregations are needed and that television ministries may serve as access points for connecting women with necessary services.

WMS-R and MAS correlations in a neuropsychological population

The present study was an attempt to examine the relationship between the Wechsler Memory Scale-Revised (WMS-R; Wechsler, 1987) and the Memory Assessment Scale (MAS; Williams, 1991). The sample consisted of 51 patients referred for neuropsychological examination. Average age was 55.29 (SD = 20.94). Average education was 11.94 years (SD = 3.18). Average Full Scale IQ was 94.75 (SD = 15.44). The results showed that no MAS index correlated higher than.60 with any of the WMS-R indices. There was minimal specific prediction between instruments across each memory domain. Agreement between the tests clinically was low as well. Corrections for such factors as age, education, intelligence or diagnosis lowered the relationships between the tests although not significantly. Corrections to the correlations for the inherent reliability of each test increased correlations between the tests but still resulted in a maximum common variance of 56% (for the visual measures) down to 40% (for General Memory). These results are consistent with the argument that "general memory" is not as useful a construct as that of "general intelligence" and that these tests of general memory measure different underlying constructs. This has important impact on how we conceive and report memory test results.

Elderly people's beliefs about influenza vaccination

BACKGROUND

Influenza is an important cause of death in the elderly. The uptake of influenza vaccination, despite its effectiveness, is low.

AIM

To examine beliefs about influenza vaccination in elderly patients at risk from influenza.

METHOD

A qualitative study using semi-structured interviews with 50 patients aged over 75 years at risk from influenza, equally divided between vaccinated and non-vaccinated groups.

RESULTS

Although they acknowledged their medical diseases, the patients regarded themselves as healthy in the sense of being independent and active. Few in either the vaccinated or non-vaccinated groups believed themselves at risk of dying from influenza even though they recognized it could be fatal for particular groups of people. Decisions to have the vaccination were based on other considerations, including whether it was thought likely to reduce (or increase) the number and severity of colds and influenza-like illnesses. Although the group with negative views towards vaccination placed more emphasis on the 'side-effects' from the vaccination (including colds and influenza), this was also common in the group who were more positive towards vaccination; however, the side-effects were interpreted in different ways.

CONCLUSION

Recommendations to vaccinate according to individual risk status are not in keeping with lay beliefs. The policy to include all people aged 75 years and older as a group requiring influenza vaccination is supported by this study. The evidence that vaccination reduces morbidity from influenza and does not cause colds and influenza needs stressing.

Attachment tests of Pasteuria penetrans to the cuticle of plant and animal parasitic nematodes, free living nematodes and srf mutants of Caenorhabditis elegans

Populations of Pasteuria penetrans isolated from root-knot nematodes (Meloidogyne spp.) and cyst nematodes (Heterodera spp.) were tested for their ability to adhere to a limited selection of sheathed and ex-sheathed animal parasitic nematodes, free living nematodes, including Caenorhabditis elegans wild type and several srf mutants, and plant parasitic nematodes. The attachment of spores of Pasteuria was restricted and no spores were observed adhering to any of the animal parasitic nematodes either with or without their sheath or to any of the free living nematodes including C. elegans and the srf mutants. All spore attachment was restricted to plant parasitic nematodes; however, spores isolated from cyst nematodes showed the ability to adhere to other genera of plant parasitic nematodes which was not the case with spores isolated from root-knot nematodes. The results are discussed in relationship to cuticular heterogeneity.

All Wales surveillance of methicillin-resistant Staphylococcus aureus (MRSA): the first year's results

Over the last five years, hospitals in Wales have experienced difficulties with increasing numbers of isolates of methicillin-resistant Staphylococcus aureus (MRSA). Continuous total population surveillance of MRSA was introduced with the objectives of gaining an understanding of the extent and variation in time and place of its occurrence, the burden of disease and possible risk factors associated with its isolation and resistance to other antibiotics. All first isolates of MRSA from both hospital and community settings and all isolates of methicillin-sensitive Staphylococcus aureus (MSSA) associated with bacteraemia and cerebrospinal fluid (CSF) isolates detected in medical microbiology laboratories in Wales were collected via CoSurv, a set of interconnected data-base modules for communicable disease control. A data set was collected on each isolate and the patient associated with that isolate and compiled centrally at CDSC (Wales) for all-Wales analysis of the MRSA situation. Surveillance started in January 1996 and at the end of the first year, 2700 new isolates of MRSA had been reported from hospital and community settings, giving a rate of 92.43/100,000 population. The incidence of MRSA from bacteraemias and CSF was 5.20/100,000 compared with 12.70/100,000 for MSSA. MRSA from bacteraemia and CSF was significantly more commonly associated with male patients than MSSA. MRSA patients were significantly older. For all MRSA isolates, the highest reporting rate was in men aged 75+ (647.21/100,000). The highest incidence of invasive disease was also in men aged 75+ (45.69/100,000). Isolates from post-surgical patients were more likely to be involved in invasive disease (OR = 2.59), P < 0.001) than strains from other sources. The majority of isolates were resistant to at least two antibiotics in addition to methicillin, most frequently erythromycin and the fluoroquinolones. Very little resistance to fusidic acid, mupirocin or rifampicin was reported. Continuous total population surveillance has provided a minimum incidence of MRSA in Wales and has allowed a simple and intelligible picture of the problem to be determined, which has been fed back to hospitals to assist decisions on control.

Sensory perception: supernormal hearing in the blind?

A recent experimental study suggests that blind individuals may compensate for their lack of vision with better-than-normal hearing. This provides support for a view dating back to 18th century philosophers, but the data raise as many problems as they solve.

Insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 in women with premenstrual syndrome

OBJECTIVE

To determine whether women with premenstrual syndrome (PMS) have aberrations of the GH axis as has been demonstrated in individuals with depression.

DESIGN

Prospective trial.

SETTING

Department of Obstetrics and Gynecology, University of California, Los Angeles.

PATIENT(S)

After prospective screening, 32 healthy women with PMS and 32 asymptomatic controls completed the study.

INTERVENTION(S)

Subjects completed a daily PMS symptom diary and a Beck Depression Inventory. They underwent phlebotomy 5 days and 12 days after the LH midcycle surge, which was identified with the use of a urinary LH detection kit.

MAIN OUTCOME MEASURE(S)

Serum levels of insulin-like growth factor-1 (IGF-1), insulin-like growth factor-binding protein-3 (IGFBP-3), E2, and progesterone.

RESULT(S)

Levels of IGF-1, IGFBP-3, E2, and progesterone did not differ between women with prospectively documented PMS and control subjects.

CONCLUSION(S)

Premenstrual syndrome and affective disorder share common symptoms and possibly a common cause. Biochemical markers such as alterations in the somatotropic system often are associated with major depression. Levels of IGF-1 and IGFBP-3 did not differ between women with PMS and control subjects, supporting the concept that PMS and endogenous depression are biologically distinct entities.

Sustained secretion of human alpha-1-antitrypsin from murine muscle transduced with adeno-associated virus vectors

Recombinant adeno-associated virus (AAV) vectors have been used to transduce murine skeletal muscle as a platform for secretion of therapeutic proteins. The utility of this approach for treating alpha-1-antitrypsin (AAT) deficiency was tested in murine myocytes in vitro and in vivo. AAV vectors expressing the human AAT gene from either the cytomegalovirus (CMV) promoter (AAV-C-AT) or the human elongation factor 1-alpha promoter (AAV-E-AT) were examined. In vitro in C2C12 murine myoblasts, the expression levels in transient transfections were similar between the two vectors. One month after transduction, however, the human elongation factor 1 promoter mediated 10-fold higher stable human AAT expression than the CMV promoter. In vivo transduction was performed by injecting doses of up to 1.4 x 10(13) particles into skeletal muscles of several mouse strains (C57BL/6, BALB/c, and SCID). In vivo, the CMV vector mediated higher levels of expression, with sustained serum levels over 800 micrograms/ml in SCID and over 400 micrograms/ml in C57BL/6 mice. These serum concentrations are 100,000-fold higher than those previously observed with AAV vectors in muscle and are at levels which would be therapeutic if achieved in humans. High level expression was delayed for several weeks but was sustained for over 15 wk. Immune responses were dependent upon the mouse strain and the vector dosage. These data suggest that recombinant AAV vector transduction of skeletal muscle could provide a means for replacing AAT or other essential serum proteins but that immune responses may be elicited under certain conditions.

The changing role of dental auxiliaries: a literature review

A review of the literature on dental auxiliaries and their utilization in the dental workforce is presented, and their future role is examined in the light of broader issues relating to changing disease patterns and service delivery. Legislative factors, productivity, quality assurance and the potential scope for dental auxiliaries in both the public sector and private practice setting are discussed. A strategy for adopting a team approach in the delivery of dental services is suggested, which would necessitate the dentist taking on the role of team leader and maintaining responsibility for overall treatment planning and quality assurance. Dental auxiliaries could provide basic preventive and restorative dental services, allowing dentists to concentrate on providing more complex high-technology treatment. Implications for the future training of dental auxiliaries are presented.

Unilateral asymptomatic carotid disease does not require surgery

BACKGROUND AND PURPOSE

The efficacy of carotid endarterectomy (CEA) in symptomatic patients with > 70% stenosis is accepted. The stroke risk of asymptomatic patients may not justify surgical intervention. The aim of this study is to use natural history data from a single unit to identify asymptomatic patients who would benefit from CEA.

METHODS

Five hundred and sixty-four patients attending for duplex ultrasound assessment of the internal carotid artery between 1986 and 1993 were retrospectively identified as focally asymptomatic with > 40% ipsilateral stenosis. Patients were traced using hospital records, family practitioner databases and the Office of Population of Census and Surveys. The number of strokes, transient ischaemic attacks and cause of death were determined. Exclusions were 15 (2.7%) asymptomatic occlusions and 49 patients (8.7%) who underwent surgery for asymptomatic disease.

RESULTS

Thirteen patients (2.6%) were not traced, leaving 487 study patients. The average follow-up was 41 months (range, 1-120 months). Mean presentation age was 69 years (S.D. 8.9), and the male to female ratio was 3:2. One hundred and fifty-six (32%) patients died. Forty-three patients suffered strokes, of whom two had bilateral strokes. In total there were 16 (i/p) strokes, 25 (c/l) strokes and four strokes undetermined. The average yearly stroke rate was 2.74 per 100 person years and the (i/p) rate 1.02 per hundred person years. There was no effect of age, sex or degree of stenosis on stroke. The presence of bilateral disease did increase the risk of stroke (rel risk 2.35, p = 0.029) but not ipsilateral stroke (rel risk 1.6, p = 0.39). Patients with unilateral asymptomatic carotid disease had an all stroke rate of less than 5% in the first year after presentation and this was unaffected by degree of stenosis. In patients with bilateral disease the stroke rate in the first year after presentation increased with degree of stenosis to a stroke rate of 9.6 per 100 person years in patients with > 90% contralateral stenosis.

CONCLUSIONS

This data suggests that CEA will not benefit patients with unilateral asymptomatic disease. Patients with bilateral disease warrant inclusion in clinical trials.

Catechol-O-methyltransferase-deficient mice exhibit sexually dimorphic changes in catecholamine levels and behavior

Catechol-O-methyltransferase (COMT) is one of the major mammalian enzymes involved in the metabolic degradation of catecholamines and is considered a candidate for several psychiatric disorders and symptoms, including the psychopathology associated with the 22q11 microdeletion syndrome. By means of homologous recombination in embryonic stem cells, a strain of mice in which the gene encoding the COMT enzyme has been disrupted was produced. The basal concentrations of brain catecholamines were measured in the striatum, frontal cortex, and hypothalamus of adult male and female mutants. Locomotor activity, anxiety-like behaviors, sensorimotor gating, and aggressive behavior also were analyzed. Mutant mice demonstrated sexually dimorphic and region-specific changes of dopamine levels, notably in the frontal cortex. In addition, homozygous COMT-deficient female (but not male) mice displayed impairment in emotional reactivity in the dark/light exploratory model of anxiety. Furthermore, heterozygous COMT-deficient male mice exhibited increased aggressive behavior. Our results provide conclusive evidence for an important sex- and region-specific contribution of COMT in the maintenance of steady-state levels of catecholamines in the brain and suggest a role for COMT in some aspects of emotional and social behavior in mice.

Sodium butyrate upregulates Kupffer cell PGE2 production and modulates immune function

The immunosuppressive effect of portal venous blood transfusions in organ transplantation has been well established and may be mediated by increased Kupffer cell production of the immunosuppressive arachidonic acid metabolite prostaglandin E2 (PGE2). In this study, butyrate, a short-chain fatty acid known to enhance gene transcription, is hypothesized to enhance Kupffer cell PGE2 production by altering cyclooxygenase or phospholipase A2 (PLA2) activity, thus augmenting the immunosuppressive effect of portal venous transfusion. Lewis rats were given a portal venous transfusion of Wistar-Firth blood or saline 1 h prior to Kupffer cell harvest. The in vitro effects of butyrate on Kupffer cell PGE2 production, cyclooxygenase, and PLA2 activity were assessed. Kupffer cell tumor necrosis factor-alpha (TNFalpha) production was also assessed due to its sensitivity to PGE2 and its proinflamatory effects. Kupffer cells from portally transfused animals produced significantly more PGE2 than saline-transfused controls. Addition of butyrate to the culture medium further increased PGE2 production by as much as sevenfold in Kupffer cells of portally transfused animals. Other short-chain fatty acids, propionate and hexanoate, did not increase PGE2 production. Butyrate added to Kupffer cells from transfused animals slightly upregulated inducible cyclooxygenase (COX-2) mRNA levels as measured by both Northern blot and reverse-transcriptase polymerase chain reaction and increased PLA2 activity fivefold as measured by Western blot. Kupffer cell immune function was also affected by in vitro butyrate treatment with a significant decrease in the production of TNFalpha. Thus, butyrate may be a useful immunoregulatory agent in organ transplantation protocols which seek to enhance transcription of immunosuppressive molecules.