Biomedical subjects
Publications and source records attributed to M Brookes.
This review illustrates some CT appearances of metastatic breast cancer in the subdiaphragmatic abdomen and pelvis. Such manifestations are not uncommon in advanced disease and familiarity will enable confident diagnosis in patients at risk for metastatic disease.
Asthma admissions have been reported to increase during thunderstorms. In some cases, this has been attributed to rises in pollen or fungal spore counts occurring alone or in combination with rainfall. We tested the hypothesis that thunderstorms in general are associated with asthma admissions, and investigated the possible roles of pollen, fungal spores, ozone, and other meteorological factors. We obtained data on multiple pollen and fungal spore counts, rainfall, temperature, ambient ozone concentrations, and asthma admissions for 32 dates when lightning strikes were recorded in the Cardiff/Newport area, and 64 matched dates in previous and subsequent years. Poisson regression models were used to investigate associations between admissions and proposed causative environmental factors. The number of asthma admissions was greater on days with thunderstorms than on control days (p<0.001). There were no associations or interactions between admissions and any pollen or fungal spore counts or rainfall. After adjusting for thunderstorms, there was an independent association between increasing ozone concentration, when temperature was included in the model, and increasing admissions (p=0.02). Asthma admissions are increased during thunderstorms. The effect is more marked in warmer weather, and is not explained by increases in grass pollen, total pollen or fungal spore counts, nor by an interaction between these and rainfall. There was an independent, positive association between ozone concentrations and asthma admissions.
A survey in 1994 showed that among the 20% of the adult English population who were identified as hypertensive, approximately 30% had their blood pressures controlled to <160 mm Hg systolic and <95 mm Hg diastolic. The 1998 Health Survey for England data update the 1994 findings in light of new thresholds and targets for treatment outlined in recent national and international guidelines. This cross-sectional survey is analyzed to describe the prevalence, awareness, treatment, and control of hypertension in a random, nationally representative sample of 11 529 English adults (>/=16 years) living in noninstitutional households in 1998 and to compare these rates with those from 1994. In 1998, 20% and 37% of adults were hypertensive according to the old (systolic >/=160 mm Hg or diastolic >/=95 mm Hg) and new (systolic >/=140 mm Hg or diastolic >/=90 mm Hg) definitions, respectively. Corresponding values in 1994 were 20% and 38%. Treatment and control rates among hypertensive adults (new definition) improved from 26% to 32% and from 6% to 9%, respectively, although 60% of those on treatment received only 1 antihypertensive drug in both years. Among persons with controlled hypertension, 59% reported having received nonpharmacological advice from their physicians in 1998 compared with 30% in 1994. Rates of hypertension treatment and control have increased significantly (P=0.05 and P<0.01, respectively) since 1994 but remain low by international standards. The 1998 data suggest that improved detection, greater use of nonpharmacological measures, and increased use of >1 antihypertensive agent per patient would produce greater success in achieving target levels. This could lead to major reductions in fatal and nonfatal cardiovascular events.
BACKGROUND: Intensive monitoring to improve glycemic control is essential for effective management of diabetes and reduction of long-term morbidity and pathology. Measurement of glycated serum proteins (fructosamine) allows more frequent assessment (monthly) of glycemic control than the 2- to 3-month window of the traditional glycated hemoglobin (HbA1c) assay. In response to concerns about assays designed to measure glycated serum proteins based on the nitroblue tetrazolium (NBT) methodology, a novel assay to measure glycated serum proteins has been developed based on the specific oxidation of the ketoamine bonds within the glycated proteins. METHODS: Reference range values for this new, enzymatic glycated-serum-protein assay (GlyPro; Genzyme Corporation, Cambridge, MA) are reported. RESULTS: The GlyPro reference range is lower and shows close correlation with ranges reported for the NBT assay. The 95% overall reference range was 122 to 236 mumol/L. CONCLUSIONS: GlyPro is a reliable, accurate assay and correlates well with the NBT assay for the measurement of glycated serum proteins. The assay may be useful in the short-term assessment of diabetes control, a necessary complement to long-term control as assessed by hemoglobin A1c (HbA1c) assays.
Some clinical studies have claimed significant reductions in the healing time of fresh fractures with the use of pulsed electromagnetic fields (PEMFs). Animal models, however, have produced more equivocal results. This investigation examined the effects of PEMF treatment on an osteochondral defect placed in the patellofemoral groove of the rat. The results indicated that PEMF enhances early vascular reaction and suppresses initial pannus proliferation. Early chondrogenesis and bone formation were consistently stimulated, and the restoration of normal bone trabeculae advanced. Pulsed electromagnetic field treatment therefore may be useful in advancing repair during the early proliferative stage. Later results were variable and suggest that prolonged use may have deleterious effects, enhancing chondrogenesis beyond a point observed in normal repair and thus delaying normal subsurface trabeculation.
OBJECTIVES: To investigate the association between spontaneous abortion and work within dry cleaning units in the United Kingdom where the solvent perchloroethylene is used. METHODS: A retrospective occupational study of reproductive outcome in 7305 women aged 16 and 45 years, who were currently or previously employed in dry cleaning or laundry units in the United Kingdom. Data on workplace exposures and reproductive outcome were obtained by postal survey. A sample of reported spontaneous abortions was validated from medical records. Machine operator versus non-operator was used as a surrogate for exposure to perchloroethylene in dry cleaning units as no data on individual doses were available for women in this study. RESULTS: The response rate was higher for current workers of dry cleaning units (78%), than for past workers of dry cleaning units (46%). Similarly, the response for current laundry workers (65%) was higher than that for past laundry workers (40%). Overall, the reproductive characteristics of the respondents were similar to expectation. Examination of exposure at the time of pregnancy, however, showed that the rate of spontaneous abortion varied according to the type of work the women did during the pregnancy or in the three months before conception: being lowest for pregnancies not exposed to either dry cleaning or laundry work (10.9%), higher for those exposed to laundry work (13.4%), and higher still for those exposed to dry cleaning work (14.8%). Within the group of pregnancies exposed to dry cleaning, the proportion was higher if the woman reported that she worked as an operator at the time of the pregnancy (17.1%) rather than as a non-operator (11.6%). Adjusted odds ratios for the period 1980-95 showed that the risk was over 50% higher in operators than non-operators (p = 0.04). The physical demands of the two jobs are likely to be similar. A higher risk was found when work as a dry cleaning operator was compared with no work in either dry cleaning or laundry units during pregnancy. Exposure to dry cleaning as a non-operator was not associated with any excess risk. CONCLUSIONS: Women who worked in dry cleaning shops at the time of their pregnancy or in the three months before who described themselves as operators were about half as likely again to report that their pregnancy ended in a spontaneous abortion than women who described themselves as non-operators.
The nutrient foramina in the human femoral diaphysis were counted in 109 cleaned and dried bones, ranging in age from 38 to 98 y. Although statistical analysis for univariate associations found that foramen number was not linked to age, sex (male/female) or side (R/L), multivariate logistic analysis revealed a significant interaction between the effects of sex and side (P < 0.01). Univariate analysis for sex and for side separately revealed a significant difference in for men number between the results for men and women for R bones 62% (18/29) vs 33% (8/24) (P < 0.04), but not for L bones 35% (9/26) vs 48% (13/27) (P < 0.28). One lower limb from 15 cadavers was perfused with a barium sulphate suspension to show the blood supply of the femoral diaphysis. Twelve were in the age group 59-88 y and considered to be senescent material. In addition, 3 more femora were perfused, 1 from a young male aged 21 y, another from a 42-y-old male considered to show early senescent changes, and a third from a man aged 56 y with a hip prosthesis in situ, to provide an example of a cortex deprived entirely of its medulla. All perfused femora were fixed and decalcified, and sections were then radiographed. Cross-sections through the middiaphysis showed that aged bone cortex is supplied predominantly from the periosteum in contrast to the medullary supply in young human and animal material. The change is attributed to increasingly severe medullary ischaemia with age, brought on by atherosclerosis of the marrow vessels. An examination of the findings reported by investigators of animal bone blood supply in the past 40 y shows a large measure of agreement. Long standing controversy seems to be based on a failure to recognise that marrow ischaemia accompanies natural senescence, affecting transcortical haemodynamics, and entraining an increasing periosteal supply for bone survival in old age. The change over from a medullary to a periosteal blood supply to bone cortex is the consequence of medullary ischaemia and reduced marrow arterial pressure, brought about by medullary atherosclerosis.
Following concern about long waiting times, a survey was carried out in the Accident and Emergency (A&E) department of Monklands District General Hospital over 5 consecutive days to investigate factors related to the bypassing of general practitioners (GPs) by 'self-referred' patients and inappropriate use of the department. Two hundred and forty-five (90.7%) of 270 non-emergency patients who attended the department during GP surgery hours completed a self-administered questionnaire. Variables measured included recent use of health services, perceptions of the GP service and the A&E service and reasons for bypassing the GP. Of the 245 patients, 49 (20%) were defined as inappropriate and 152 (62%) were self-referred. Self-referred patients were no more likely to use the A&E department inappropriately than those who were referred.
Studies in both the UK and the USA continue to show that gay and bisexual men put themselves at risk of exposure to HIV through unprotected intercourse, most often with regular partners. As part of a larger study of homosexually active men, 310 men who had had unprotected anal intercourse with a man in the previous year were asked to describe the last occasion on which this had happened. The majority of men had had unprotected intercourse with a regular partner and did not perceived it as risky, although most did not know the HIV status of their partner. Regular and non-regular partners were perceived differently. Men were more likely to be emotionally involved in regular partners and to perceive unprotected penetrative sex with a regular partner as not risky. Future health education initiatives must take into account men's emotional involvement in regular partners and their perception of unprotected intercourse with such partners as not risky.
Interference with venous outflow from a limb to stimulate fracture repair and bone growth has a long history, and its beneficial effects have been confirmed by many experimental and clinical studies. With the development of fracture fixation systems, the therapeutic use of circulatory intervention became redundant. Recently, a venous tourniquet effect has been cited to explain the enhancement of bone healing observed after fracture fixation with the Aircast system. As bone appears to be altered by venous stasis, it is important to characterise the vascular perturbations leading to these changes. Previous studies have often given conflicting results. This study investigated the short and long term haemodynamic effects of femoral vein ligation. Changes in blood flow rate and blood volume in the distal femur and proximal tibia of the rat were examined at 6 h and 1, 3 and 7 d following unilateral femoral vein ligation, and at 8 and 16 wk. Blood flows and volumes were generally reduced in the ligated limb 6 h after femoral vein ligation. This initial depression was followed by a relative increase (comparing the ligated limb with the contralateral unoperated bone) in blood volume during the 1st week. A significant relative reduction in epiphyseal vascular space was observed after 16 wk. A sustained reduction of arterial input to whole femora and tibiae was present in the ligated limb throughout the investigation although, for the cancellous knee joint epiphysis of the tibia, a localised relative increase in flow was apparent during the 1st week, again comparing the ligated limb with the nonligated contralateral bone.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVE: To evaluate the extent to which 'high-risk' sexual behaviour is influenced by awareness of partners' HIV status among gay men. DESIGN: Structured interviews and collection of saliva samples for anonymous linked testing for HIV-1 antibodies. SETTING: Genitourinary medicine clinics and the gay community. SUBJECTS: Men (n = 677) who reported sexual contact with another man in the last 5 years. RESULTS: The majority of respondents (63%) had had an HIV-antibody test. Analysis of data showed that in 15% of the respondents' 1380 partnerships, HIV status was known by both parties. However, the majority of partnerships involved only safe sex. Only 26% of the partnerships in which unprotected penetrative anal sex had occurred involved mutual knowledge of HIV status and was most likely to occur with regular rather than non-regular/causal partners. Logistic regression revealed that this latter association could not be explained in terms of mutual HIV status knowledge. CONCLUSIONS: Despite widespread HIV testing, the majority of gay men engaging in high-risk sex are unaware of their partner's HIV status.
BACKGROUND: Primary care has an important role to play in the prevention and management of the human immunodeficiency virus (HIV). It has been suggested that homosexual men experience a variety of problems in relation to primary care. AIM: As part of a larger study, it was decided to examine the extent to which a sample of homosexually active men experienced difficulties in general practice and whether they consulted their general practitioner for problems related to HIV or the acquired immune deficiency syndrome (AIDS). METHOD: Homosexual men were recruited for interview in 1991-92 from a variety of sources including genitourinary clinics and homosexual organizations. RESULTS: Of 623 men registered with a general practitioner 44% had not informed their general practitioner of their sexual orientation and 44% of the 77 men who were HIV antibody positive, as confirmed by the study, had not informed their general practitioner of this fact. Men who viewed their practice as unsympathetic towards homosexual men were less likely to have informed their general practitioner of their sexual orientation or HIV status. The majority of men (87%) nevertheless viewed primary care as an appropriate source of HIV/AIDS advice. CONCLUSION: There is considerable scope for improvement in the acceptability of general practice to homosexual men.
OBJECTIVE: To describe the sexual risk behaviour of and HIV and hepatitis B antibody prevalence in gay men in England. DESIGN: Cross-sectional. RESPONDENTS: Gay men recruited from community settings (bars, clubs, gay organizations) and genito-urinary clinics in London, Manchester, the Midlands and Bristol; men who participated in an earlier study. METHODS: Interview including demographic information, sexual behaviour, partner type and health service use. Subjects donated saliva, which was screened for antibodies to HIV-1 by immunoglobulin G (IgG) antibody capture enzyme-linked immunosorbent assay (GACELISA) and to hepatitis B core (HBc) antigen by IgG antibody capture radioimmunoassay (GACRIA). RESULTS: Ninety-four out of 580 (16.2%) men were HIV-antibody-positive; 6.2% of men aged < or = 25 years were positive versus 19.5% of men aged > or = 26 years. HIV-antibody prevalence was highest in London (21.1%), and twice that previously reported outside London (10.5%). Ninety-four out of 568 (16.5%) men were HBc-antibody-positive; 6.9% of men aged < or = 25 years were positive versus 19.7% of men aged > or = 26 years. Anti-HBc prevalence was highest in London (19.8 versus 12.7% outside London). Manual workers were more likely to be anti-HBc-positive, as were men who reported recent high-risk intercourse. Sexually transmitted diseases associated with frequent partner change (gonorrhoea, non-specific urethritis) were reported. CONCLUSION: The HIV epidemic in gay men in England continues, particularly outside London, where prevalence was double that of previous studies. We found relatively high rates of infection in young men whose main sexual experience has been in a time of unprecedented awareness of AIDS. Our data on hepatitis B suggests that further pro-active immunization programmes are urgently required. These findings add to concerns about provision of interventions targeting gay men.
Arteriolar blockade is probably the most widely used laboratory method for bone blood flow measurement. At first, cheap labelled cationic resin particles were used. These have largely been displaced by labelled microspheres, which have theoretical advantages but are expensive. This investigation compares measurements of bone blood flow made with the 2 different materials, using a reference artery method. Resin particles (1.4 mg per rat) were compared with 2 different doses of 85Sr-labelled microspheres (1 mg and 3 mg per rat). Whole bone blood flow from the 3 groups was not statistically different. Regional bone blood flow comparisons using resin particles and 1 mg dose microspheres showed no significant difference in epiphyses or metaphyses. In the resin group, marrow flow was significantly lower, and cortical flow elevated. It is suggested that these differences are caused by leaching of 59Fe to plasma, and methods of preventing this are discussed. Measured flow rates were significantly increased in the tibial marrow and cortex using 3 mg microspheres, compared with the 1 mg dose. This increase may reflect better sampling of the arteriolar beds. We conclude there is little advantage in using microspheres for bone blood flow measurement. When sufficient resin particles of appropriate size are injected and procedures are adopted to prevent leaching of isotope to plasma, the observed measurements are essentially identical.
We perfused 16 human femora with a 50% barium sulphate suspension and studied the intra-osseous vessels by microfocal radiography and histology. There were few anastomoses between the vessels of the greater trochanter and those of the adjacent cancellous bone of the shaft. Ischaemia of the trochanter may contribute to nonunion after trochanteric osteotomy.
The intrinsic blood supplies of 13 human patellae with varying degrees of articular surface degeneration were studied by perfusion techniques. Disruption of the normal pattern of arterial arcades correlated with increasing surface wear.
OBJECTIVE: To determine the factors influencing the risk of an acute traumatic intracranial haematoma in children and adults with a recent head injury. DESIGN: Prospective study of incidence of risk factors in samples of patients attending accident and emergency departments and in all patients having an acute traumatic intracranial haematoma evacuated in one regional neurosurgical unit during 11 years. SETTING: Accident and emergency departments in Scotland or Teesside and regional neurosurgical centre in Glasgow. PATIENTS: 8406 Adults and children (less than or equal to 14 years) who attended accident and emergency departments and 1007 consecutive patients who had an operation for an acute traumatic intracranial haematoma. Data were complete in 8366 and 960 patients respectively. RESULTS: Overall, children were less at risk than adults (one in 2100 v one in 348 respectively). In both age groups the presence of a skull fracture and changes in conscious level permitted identification of subgroups of patients with widely differing degrees of risk. In children the absolute risk ranged from one in almost 13,000 without a fracture or altered conscious level to one in 12 for a child in a coma and with a fracture; the pattern was similar in adults, the risks in corresponding groups ranging from one in almost 7900 to one in four. CONCLUSIONS: Although children attending hospital after a head injury have a lower overall risk of a traumatic haematoma, the main indicators of risk, a skull fracture and conscious level, are the same as in adults, and the pattern of their combined effect is similar. Guidelines for managing adults with recent head injury may therefore be applied safely to children; with the increasing provision of facilities for computed tomography they should be revised to ensure early scanning of more patients with head injury.