Biomedical subjects

K D MacRae

Publications and source records attributed to K D MacRae.

At least 37 records · Page 2Linked to original sources

PubMed1997

Oestrogen increases S-phase fraction and oestrogen and progesterone receptors in human cervical cancer in vivo.

Although cancer of the cervix is traditionally considered not to be responsive to steroid hormones, an in vitro study has reported that the addition of oestrogen increased cellular proliferation in a cervix cancer cell line that was inhibited by progesterone. We investigated whether the reported in vitro effects of oestrogen and progesterone on cellular proliferation can be replicated in locally advanced cervical cancer in vivo and whether these effects, if any, are related to oestrogen and progesterone receptor (ER and PgR) content of the tumour. One hundred post-menopausal patients with locally advanced cervical cancer were systematically allocated by rotation to the four treatment groups: (1) control group receiving no treatment; (2) ethinyl oestradiol 50 micrograms: (3) norethisterone 5 mg: (4) a combination of ethinyl oestradiol and norethisterone. Hormone treatment (five doses) was given orally every 12 h. Tissue biopsies were taken before and 12 h after the last hormone treatment. S-phase fraction (SpF) was measured by flow cytometry, and ER and PgR were measured by enzyme immunoassay. Results were analysed using two-factor analysis of variance, the factors being oestrogen-absent or present- and progesterone-absent or present. The main effects of oestrogen were increases in SpF, ER and PgR, which were statistically significant (P = 0.0056, 0.0009 and 0.01 respectively), indicating that there is much greater change in these three parameters in the presence of oestrogen (mean changes 7.808%, 6.258 fmol mg-1 and 12.716 fmol mg-1 for SpF, ER and PgR respectively) than in its absence (mean change -1.986%,-3.041 fmol mg-1 and 1.736 fmol mg-1 respectively). The progestogen main effect and the oestrogen-progestogen interaction were not significant. The rise in SpF, ER and PgR in the presence of oestrogen had a correlation coefficient with the initial ER values of -0.0565, -0.2863 and -0.1230 respectively, none being statistically significant, suggesting that the oestrogen actions were not strictly related to baseline ER concentrations. The combined median baseline ER and PgR values of the four groups were 1.48 fmol mg-1 and 0.80 fmol mg-1 respectively. Our results show that oestrogen is capable of increasing SpF in locally advanced cervical cancer in vivo and may help to revive interest in the use of oestrogen as a radiosensitizing agent in the treatment of this disease.

Adenocarcinoma↗

PubMed1997

Sexual relationships, risk behaviour, and condom use in the spread of sexually transmitted infections to heterosexual men.

OBJECTIVE: To examine the effect of patient defined non-regular sexual relationships and other risk behaviours on the incidence of sexually transmitted infections in heterosexual men and the role of condom use in the prevention of their spread. DESIGN: A prospective cross sectional study of sexual behaviour reported by a standardised self administered questionnaire in new patients who presented for screening and diagnosis. SETTING: A genitourinary medicine clinic in west London. SUBJECTS: 957 consecutive newly attending heterosexual men who completed a sexual behaviour questionnaire in 1993/94. MAIN OUTCOME MEASURES: Variables relating to sociodemographic status, sexual behaviour, condom use, sexually transmitted infections and testing for HIV infection, stratified by the reporting of non-regular partners. RESULTS: We found that the 65% of men who reported non-regular sexual partners were more likely to be white collar class (d = 7.5%, 95% CI = 1.3, 13.7) and to have had sexual intercourse with non-United Kingdom born women (d = 7.8%, 95% CI = 3.5, 12.2). They also reported coitarche before 16 years of age (d = 13.4%, 95% CI = 8.0, 18.8) and many more sexual partners both in the last year (d = 13.1%, 95% CI = 10.2, 16.0) and in their lifetime (d = 27.9%, 95% CI = 21.6, 34.2). They were significantly more likely to practise anal intercourse (d = 8.7%, 95% CI = 3.3, 14.1), to smoke (d = 16.3%, 95% CI = 9.8, 22.6), to drink alcohol (d = 4.9%, 95% CI = 1.2, 8.6), and to have chlamydial infection (d = 5.7%, 95% CI = 2.2, 9.2), of which 30% was subclinical. Increasing condom use with regular partners correlated with decreasing incidence of urethral infection (gonorrhoeal and/or chlamydial infection) (p < 0.03) and candidal balanitis (p < 0.03) and a greater likelihood of no infection being detected (p = 0.0002). Use of condoms with non-regular partners was much more frequent than with regular partners (d = 21.4%, 95% CI = 16.7, 26.1). However, we found evidence of oral transmission of urethral gonorrhoea and chlamydial infection among men who reported always using condoms. HIV infection was found in only two men (0.2%), both of whom reported intercourse with non-United Kingdom born women. CONCLUSIONS: Heterosexual men who reported non-regular sexual relationships compensated for their increased risk lifestyle by using condoms more frequently and showed only an increased incidence of chlamydial infection. More consistent condom use with regular partners was significantly associated with the absence of sexually transmitted infection. These findings suggest that transmission between regular partners has been underestimated.

Adolescent↗

PubMed1996

Third generation oral contraceptives and risk of venous thromboembolic disorders: an international case-control study. Transnational Research Group on Oral Contraceptives and the Health of Young Women.

OBJECTIVE: To test whether use of combined oral contraceptives containing third generation progestogens is associated with altered risk of venous thromboembolism. DESIGN: Matched case-control study. SETTING: 10 centres in Germany and United Kingdom. SUBJECTS: Cases were 471 women aged 16-44 who had a venous thromboembolism. Controls were 1772 women (at least 3 controls per case) unaffected by venous thromboembolism who were matched with corresponding case for age and for hospital or community setting. MAIN OUTCOME MEASURES: Odds ratios derived with stratified analyses and unconditional logistic regression to adjust for potential confounding variables. RESULTS: Odds ratios (95% confidence intervals) for venous thromboembolism were: for any oral contraceptives versus no use, 4.0 (3.1 to 5.3); for second generation products (low dose ethinyl-oestradiol, no gestodene or desogestrel) versus no use, 3.2 (2.3 to 4.3); for third generation products (low dose ethinyloestradiol, gestodene or desogestrel) versus no use, 4.8 (3.4 to 6.7); for third generation products versus second generation products, 1.5 (1.1 to 2.1); for products containing gestodene versus second generation products, 1.5 (1.0 to 2.2); and for products containing desogestrel versus second generation products, 1.5 (1.1 to 2.2). Probability of death due to venous thromboembolism for women using third generation products is about 20 per million users per year, for women using second generation products it is about 14 per million users per year, and for non-users it is five per million per year. CONCLUSIONS: Risk of venous thromboembolism was slightly increased in users of third generation oral contraceptives compared with users of second generation products.

Adolescent↗

PubMed1996

Third generation oral contraceptives and risk of myocardial infarction: an international case-control study. Transnational Research Group on Oral Contraceptives and the Health of Young Women.

OBJECTIVE: To test whether use of combined oral contraceptives containing third generation progestogens is associated with altered risk of myocardial infarction. DESIGN: Matched case-control study. SETTING: 16 centres in Austria, France, Germany, Switzerland, and the United Kingdom. SUBJECTS: Cases were 153 women aged 16-44 with a myocardial infarction event. Controls were 498 women (at least 3 controls per case) unaffected by myocardial infarction who were matched with their corresponding case for age and for hospital or community setting within four months of the index infarction. MAIN OUTCOME MEASURES: Odds ratios derived with stratified analyses and unconditional logistic regression to adjust for potential confounding variables. RESULTS: The estimated odds ratio for myocardial infarction of third compared with second generation oral contraceptives among all 651 study subjects was 0.36 (95% confidence interval 0.1 to 1.2) (P = 0.11). The odds ratio for the United Kingdom and Germany alone was 0.45 (0.1 to 1.8) (P = 0.26). Other odds ratios for the five countries were 3.1 (1.5 to 6.3) (P = 0.003) for use of second generation products v no current use and 1.1 (0.4 to 3.4) (P = 0.9) for use of third generation products v no current use. Among the confounding variables the independent contribution of smoking (for which adjustment was made in the above estimates) proved to be important (10.1 (5.7 to 17.9), P < 0.001). CONCLUSION: An odds ratio of 0.45 with wide confidence intervals shows that third generation oral contraceptives compared with second generation products are associated with a reduced risk of myocardial infarction or with no difference. This finding from an interim analysis should be interpreted with extreme caution. However, the excess risk of venous thromboembolism associated with the use of third generation products may be balanced by the reduced risk of myocardial infarction associated with the same products.

Adolescent↗

PubMed1996

The increased risk of venous thromboembolism and the use of third generation progestagens: role of bias in observational research. The Transnational Research Group on Oral Contraceptives and the Health of Young Women.

A matched case-control study was undertaken in 10 centers in Germany and the United Kingdom to explore the association of current use of major combination oral contraceptives with the occurrence of venous thromboembolism. The cases recruited were 505 women aged 16-44 years with venous thromboembolism, controls were 1877 women (at least 3 controls per case) matched for 5-year age group and region without VTE. The main outcome measures were odds ratios derived by comparing current use of a specific oral contraceptive or group of OC against current use of other groups or against no current use of OC. The odds ratios (95% confidence intervals) for venous thromboembolism were: for third generation products (low dose ethinyloestradiol, gestodene and desogestrel) versus second generation products (low dose ethinyloestradiol, no gestodene and desogestrel, 1.5 (1.1 to 2.0), for third versus second generation products with norgestimate included in third generation, 1.6 (1.2 to 2.2). The odds ratios for current use for women aged 16-44 of specific progestagens versus levonorgestrel-containing compounds were 1.7 (1.1 to 2.6) for gestodene, 1.8 (1.2 to 2.6) for desogestrel, 1.9 (1.0 to 3.6) for norgestimate and 1.3 (0.7 to 2.5) for progestagen-only pills. For women aged 25 to 44 likely to be exposed to any of these progestagens, odds ratios for the comparison of progestagens versus levonorgestrel showed a successive increase by market introduction ranging from 1.5 (0.9 to 2.5) for desogestrel with 30 micrograms oestrogen content (introduced 1981) to 2.8 (1.3 to 6.5) for desogestrel with 20 micrograms oestrogen content (introduced 1992) significant in linear trend analysis (p = 0.00012). The influence of norgestimate classification as third or second generation product does not significantly alter the results regarding the association of third generation products and venous thromboembolism. A direct comparison of current use of norgestimate (which is primarily metabolized to levonorgestrel) versus levonorgestrel shows an increased odds ratio. The trend of increasing risk of progestagens by recency of market introduction when compared with levonorgestrel is strongly indicative of the existence of external bias due to attrition of susceptibles.

Adolescent↗

PubMed1995

Trends in female sexual behaviour and sexually transmitted diseases in London, 1982-1992.

OBJECTIVE: To measure changes in female sexual behaviour, including condom use, and their relationship with the incidence of sexually transmitted and other genital diseases in women during the decade 1982-92. DESIGN: A prospective series of cross-sectional surveys of sexual behaviour reported by a standardised self-administered questionnaire in new patients who presented for screening and diagnosis. SETTING: A genitourinary medicine clinic in West London. SUBJECTS: 4089 consecutive newly attending patients who completed sexual behaviour questionnaires during 1982, 1987, 1989 and 1992. MAIN OUTCOME MEASURES: Trends in socio-demographic status, sexual behaviour, condom-use, sexually transmitted diseases and other genital infections diagnosed by routine clinical and laboratory methods. RESULTS: Women reported significantly increasing condom use (from 3.6% to 20.7%) and decreasing oral contraception (from 51.2% to 40.1%), but the proportion who used no contraception (23.6% to 24.7%) and the proportion who had never been pregnant (58.3% to 59.9%) remained similar. Numbers of sexual partners in the preceding year decreased (p < 0.001) and an increasing proportion of women practised oral intercourse (p < 0.001). During the same period, there was a progressive decline (p < 0.001) in the incidence of gonorrhoea, chlamydial infection and trichomoniasis by approximately two-thirds. However, the incidence of vaginal candidosis (p < 0.001), bacterial vaginosis (p < 0.001) and genital warts (p < 0.01) increased. CONCLUSIONS: Increasing use of condoms for vaginal intercourse with both regular and non-regular partners has been associated with a decrease in the incidence of gonorrhoea, chlamydial infection and trichomoniasis. There was also an increase in the practice of fellatio and a change in the spectrum of STD and other genital infections with little net reduction in morbidity. HIV infection showed no evidence of heterosexual spread.

Adolescent↗

PubMed1995

Heterosexual relationships and condom-use in the spread of sexually transmitted diseases to women.

OBJECTIVES: To examine the effect of patient-defined non-regular heterosexual relationships on the incidence of sexually transmitted diseases and other genital infections in women and the role of condom use in the prevention of their spread. DESIGN: A cross-sectional study of sexual behaviour reported by a standardised self-administered questionnaire in new patients who presented for screening and diagnosis. SETTING: A genitourinary medicine clinic in West London. SUBJECTS: 938 consecutive newly attending women who completed a sexual behaviour questionnaire in 1992. MAIN OUTCOME MEASURES: Variables relating to socio-demographic status, sexual behaviour, condom use, sexually transmitted diseases and other genital infections stratified by the reporting of non-regular partners. RESULTS: We found that women who reported non-regular sexual partners were more likely to be single (p = 0.0001), white (p < 0.0001), have had coitarche before 17 years of age (p = 0.003) and many more sexual partners both in the last year and in their life-time (p < 0.0001) and were more likely to practise fellatio (p < 0.0001), anal penetration (p = 0.004) and to be smokers (p < 0.0001). Paradoxically, the incidence of sexually transmitted diseases and other genital infections was no higher in this group than in the group of women who did not have non-regular partners. Increasing condom use with regular partners correlated with decreasing incidence of gonorrhoea (p < 0.001), chlamydial infection (p < 0.01) and trichomoniasis (p < 0.02), but increasing condom use with non-regular partners did not show this trend. CONCLUSIONS: Regular heterosexual partners play the major role in transmission of bacterial sexually transmitted diseases to women. This is significantly influenced by use of condoms.

Adolescent↗

PubMed1993

Risk profiles for genital infection in women.

OBJECTIVE: To determine independent risks with predictive value for specific sexually transmitted diseases in women. DESIGN: A prospective study of reported sexual behaviour in patients who presented for screening and diagnosis of sexually transmitted diseases. SETTING: A genitourinary medicine clinic at the West London Hospital. SUBJECTS: 1025 consecutive newly attending patients who completed a sexual behaviour questionnaire between February and June 1982. MAIN OUTCOME MEASURES: Sexual behaviour reported by standardised self-administered questionnaire and sexually transmitted diseases diagnosed by routine clinical and laboratory methods. RESULTS: Independent risks for gonorrhoea were teenage (RR 2.0), black race (RR 2.0), more than two partners in the past year (RR 2.2) and previous pregnancy (RR 2.1). Trichomoniasis (RR 2.5), chlamydial infection (RR 1.8) and pelvic inflammatory disease (RR 4.8) also had significant predictive value. Conversely, gonorrhoea proved a risk for chlamydial infection (RR 2.1) together with age under 25 years (RR 2.3) and more than five partners in the previous year (RR 2.2). Ano-genital herpes was predicted by a total of more than 10 sexual partners (RR 2.6) and by both anal (RR 2.2) and oral intercourse (RR 2.9). Age under 25 years was the only independent risk for ano-genital warts (RR 2.0). We found no evidence that either vaginal candidosis or bacterial vaginosis were sexually transmitted. The risk for any genital infection was increased by more than one sexual partner in the preceding year (RR 1.7) and black race (RR 2.0). CONCLUSIONS: Sexually transmitted diseases show both similarities and differences in the risk factors associated with their transmission. These risk profiles facilitate the targeting of health education measures for those sections of the community at greatest risk and form a baseline for the future assessment of the effects of condom protected sexual intercourse and other safer sexual practices.

Adolescent↗

PubMed1992

A colposcopic case-control study of cervical squamous intraepithelial lesions in women with anogenital warts.

OBJECTIVE: To assess whether anogenital warts, present or past, are an indication for women to be referred for colposcopy. DESIGN: A case control study comparing patients with and without a history of anogenital warts. SETTING: A department of genitourinary medicine in West London. PATIENTS: 468 patients examined by colposcopy between January 1985 and December 1987 of whom 147 (31%) had abnormal cytology, 163 (35%) had anogenital warts and 158 (34%) had both. MAIN OUTCOME MEASURES: Colposcopic findings and histology of cervical biopsies compared with behavioural and disease variables. RESULTS: Human papillomavirus infection (HPVI) of the cervix showed no relationship with a life time history of vulval warts, or with the presence of anogenital warts on clinical examination, or with any parameter of sexual behaviour included in the study. Cervical intraepithelial neoplasia (CIN) was strongly associated with current IUCD usage (RR = 7.75) and coitarche under 16 years of age (RR = 3.72), but a history of vulval warts yielded a negative association (RR = 0.34), suggesting a protective effect. This relationship held true when cytological dyskaryosis was made the dependent variable (RR = 0.24). CONCLUSIONS: Anogenital warts are not a risk for subclinical cervical HPVI or for CIN and therefore not an indication for colposcopy.

Adult↗

PubMed1992

Identification of risk factors for radiographic hyperparathyroidism in 422 patients with end-stage renal disease: development of a clinical predictive index.

The hand radiographs of 422 patients with end-stage renal failure were graded for severity of subperiosteal resorption. Two hundred and seventy-three patients (64.7%) had no evidence of resorption; 114 (27.0%) showed resorption, in 32 of whom it was severe (7.6% of the total). Thirty-five patients (8.3%) were assessed as having doubtful evidence of subperiosteal resorption. Age, gender, race, renal diagnosis, duration of renal failure and vitamin D status were assessed as potential risk factors for the development of subperiosteal resorption. Duration of renal failure, female gender, young age, and certain renal diagnostic groups namely obstructive uropathy, unknown diagnosis, presumed glomerulonephritis and tubulointerstitial disease emerged as independent risk factors. Diabetic patients appeared to be least at risk of developing subperiosteal resorption. Patients whose renal failure was of unknown duration showed a degree of risk similar to those whose duration was < 2 years. In order to identify prospectively patients likely to develop subperiosteal resorption by the time they reach renal replacement therapy, the relative risks were used to create a risk index. Use of such an index might allow prophylactic treatment to be given to those particularly at risk. The concept of a risk index requires testing by a prospective study, which is in progress.

Adolescent↗

PubMed1991

A meta-analysis of reported correlations between prognostic factors in breast cancer: does axillary lymph node metastasis represent biology or chronology?

A statistical overview of published results on correlations between various prognostic factors in breast cancer was undertaken. A distinction was made between clinical (or anatomical) prognostic factors--namely, axillary lymph node status and tumour size--and eight different biological prognostic factors. The latter included: tumour grade, oestrogen and progesterone receptor status, thymidine labelling index, DNA ploidy, S-phase fraction, epidermal growth factor receptor expression and c-erbB-2 gene amplification (or overexpression). 139 articles were eligible for review which reported a total of 432 individual correlations. A simple form of meta-analysis was employed: the counting method, in which the number of studies achieving a statistically significant correlation or not were counted. For each possible correlation examined, the proportion of studies showing a statistically significant correlation was calculated and an exact binomial 99% confidence interval determined for that proportion. If the 99% confidence interval included 5% (the proportion of correlations that would be expected to be statistically significant if the null hypothesis was true), it was taken as failing to exclude the null hypothesis of a zero correlation, while if it excluded 5% it was taken as rejecting the null hypothesis of a zero correlation. A broad agreement was found among published reports on the existence of a statistically significant correlation between the various biological prognostic factors in breast cancer. Of the 20 correlations examined, 18 had a 99% confidence interval excluding 5%, thus rejecting the null hypothesis of a zero correlation. On the other hand, a completely different result was obtained when reports on possible correlations between lymph node status and tumour size on the one hand and the eight biological prognostic factors on the other were analysed. Of the 16 correlations examined, 13 had a 99% confidence interval including 5%, failing to reject the null hypothesis of a zero correlation. These observations suggest the hypothesis that the prognostic influence of node status and tumour size cannot be explained by an analysis of the biology of breast cancer; and is compatible with the contention that axillary node status is merely a reflection of the relative chronological age of breast cancer.

Breast Neoplasms↗

PubMed1991

Racial origin and primary renal diagnosis in 771 patients with end-stage renal disease.

A total of 771 individuals with end-stage renal disease treated at one centre from 1964 to 1990 were studied. Data on racial origin, gender, age, and primary renal diagnosis were analysed. The male: female ratio (468:303) and proportions of individuals in different diagnostic groups (renal diagnosis based on European Dialysis and Transplant Association (EDTA) groups) were similar to EDTA data for the UK as a whole. Racial distribution was Caucasian 79.0%, Indian subcontinent (Is-c) 12.7%, Caribbean, 5.6%, African 1.6% and other Asian 1.2%. In Britain individuals from the Is-c constitute 2.2% of the general population and those from the Caribbean 1.0%. We found differences in the distribution of primary renal disease among patients from different racial groups. Adult polycystic kidney disease was almost entirely confined to Caucasians (75 to 79 patients). Diabetic nephropathy was relatively more common in individuals (especially males) from the Is-c. Hypertensive renal disease was relatively more common in those of Caribbean descent and in Africans, whilst 'Unknown diagnosis' was most common in patients from the Is-c.

Adolescent↗

PubMed1991

The renal vascular response to mild and severe haemorrhage in the anaesthetized rat.

1. In order to document the characteristics of the renal vascular response to blood losses of varying severity, Inactin-anaesthetized rats were subjected to a haemorrhage of 5, 10, 15 or 20 ml (kg body weight)-1, while a fifth group (control rats) remained unbled. Radioactive microspheres (diameter 10 microns) were used to determine cardiac output, total renal blood flow and the distribution of blood flow within the kidneys; measurements were made before and 5-120 min after haemorrhage. 2. In control animals none of the variables studied changed significantly during the experimental period. 3. Immediately after haemorrhage there were reductions in arterial pressure and cardiac output which were roughly proportional to the severity of haemorrhage. Arterial pressure recovered to some extent during the next 30 min, then stabilized; cardiac output recovered only slightly. 4. Total renal blood flow fell to an extent dependent on the degree of haemorrhage, with no evidence of subsequent recovery. The approximate reductions in renal blood flow were 2% (n.s.), 15%, 30% and 50% after bleeds of 5, 10, 15 and 20 ml kg-1, respectively. Renal vascular resistance increased consistently only in the groups bled 15 and 20 ml kg-1. When renal blood flow was expressed as a fraction of cardiac output, it increased during the period immediately after haemorrhage, indicating some degree of 'protection' of the renal circulation in the face of hypotension. 5. Measurements of intrarenal blood flow indicated a significantly reduced flow to the superficial cortex after every degree of haemorrhage. Inner cortical flow was less affected and fell significantly only in the groups bled 15 and 20 ml kg-1; blood flow to the mid-cortex was intermediate.

Anesthesia↗

PubMed1991

Trends in sexual behaviour and HIV testing among women presenting at a genitourinary medicine clinic during the advent of AIDS.

Changes in female sexual behaviour with the advent of AIDS and safer sex campaigns were studied. Subjects were drawn from a wide social spectrum of women attending an STD clinic in West London where there is a high prevalence of HIV infection among homosexual men. Between 1982 and 1989, 4224 women answered a self-administered questionnaire: women who reported more than one sexual partner in the previous year fell from 56.9% in 1982 to 51.8% in 1989 (p = 0.003). Anal intercourse showed no change and was reported by 8.8% in 1982 and 9.4% in 1989 (p = 0.8). Oral intercourse increased from 36.9% in 1982 to 44.7% in 1989 (p = 0.001). Condom use for contraception increased from 3.6% in 1982 to 16.2% in 1989 (p less than 0.001). Between 1987 and 1989, 35.6% of 3199 women reported having non-regular partners with no significant trend over this period; these women had earlier coitarche (17.0 years cf 17.9 years), many more partners (p less than 0.0001) and more practised anal (p = 0.007) and oral (p less than 0.0001) intercourse. However, frequent use of condoms doubled from 23.6% in 1987 to 47.6% in 1989. During this period, the prevalence of antibody to HIV (anti-HIV) remained unchanged (0.27-0.37%), but more women declined to be tested. Anonymised testing showed that none of those who refused consent for named testing was anti-HIV positive. It is concluded that significant changes in female sexual behaviour have taken place with the advent of AIDS but there has been no evidence of heterosexual spread beyond the confines of well defined risk behaviours. Risks of the magnitude reported in homosexual men were not found in heterosexual women.

AIDS Serodiagnosis↗

PubMed1991

Reference values and prediction equations for normal lung function in a non-smoking white urban population.

Prediction equations for normal lung function have been derived from tests on 179 healthy, non-smoking, white urban dwellers. The subjects, 96 women (height 1.46-1.77 m) and 83 men (height 1.61-1.96 m) aged 18-86 years, underwent measurements of spirometric flow and volume, multi-breath helium dilution lung volumes, and single breath carbon monoxide transfer factor and the single breath nitrogen washout test. Regression analysis using height, age, and weight as independent variables was used to provide predicted values for both sexes. Correlation coefficients were similar to those found in previous studies but normal ranges for spirometic measurements were narrower than in many previous studies, and spirometric flow and volume measurements were higher than those obtained in studies that included cigarette smokers, reflecting our more stringent criteria for selecting subjects and the newer standardised technical methods adopted. Multi-breath helium dilution values for total lung capacity were similar to those found in previous studies but the inspiratory vital capacity was larger and the residual volume reduced. Values for carbon monoxide transfer factor and the single breath nitrogen washout did not differ significantly from existing values. A complete set of lung function reference values and prediction equations for both sexes has been derived from a single population. The exclusion of cigarette smokers and subjects with respiratory symptoms has produced values that should have a greater sensitivity in the detection of mild lung disease.

Adolescent↗

PubMed1991

The language of breathlessness. Use of verbal descriptors by patients with cardiopulmonary disease.

The main objective of the present study was to test the hypothesis that patients with cardiopulmonary disease can reliably identify different sensory qualities of their experience of breathlessness. A secondary aim was to examine whether there was any relationship between such specific descriptors of the sensation of breathlessness and a patient's clinical diagnosis. A randomly ordered list of 45 descriptors of breathing discomfort related to exertion was administered on two occasions to 208 patients with cardiopulmonary disease; patients identified the descriptors that applied to their own experience. A total of 169 patients were considered reliable in that their responses were repeatable between questionnaires; there was evidence that an individual's reliability could be assessed by asking repeat questions within a questionnaire. With these patients, individual descriptors generated different degrees of yes and no response and were answered with a variable consistency, suggesting that some questions may be more useful than others in discriminating between the quality of patients' sensations. Overall, patients with obstructive disorders (asthma and chronic obstructive airways disease [COAD]) answered yes more often than those with restrictive or cardiac conditions, possibly reflecting differences in severity of disease. A cluster analysis separated the descriptors into 12 groups which appeared to describe different aspects of breathing discomfort. Relative to their response to other clusters, COAD patients were more inclined to identify distress, asthma patients to indicate wheeziness, restrictive patients to report rapid breathing, and the cardiac group to describe a need to sign. A second cluster analysis separated patients into 12 groups based on responses for the descriptor clusters.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Multi-breath and single breath helium dilution lung volumes as a test of airway obstruction.

Total lung capacity (TLC) and residual volume (RV) measurements derived from multi-breath and single breath helium dilution methods were combined to produce four indices of gas mixing: single breath volume/multi-breath volume ratio (TLCr, RVr) or multi-breath volume minus single breath volume difference (TLCd, RVd). The reproducibility of these indices and their sensitivity and specificity in discriminating between normal subjects and those with mild asthma and severe chronic obstructive pulmonary disease (COPD) was assessed. The total lung capacity ratio (TLCr) was the superior variable overall, providing a single range for both sexes with a specificity and sensitivity similar to that of the forced expiratory volume in one second (FEV1) in the diagnosis of airflow obstruction. Despite the similar sensitivity, correlation between TLCr and FEV1 was only moderate (r = 0.56). This may reflect greater influence of peripheral rather than central airflow obstruction on TLCr. Combining both tests improved sensitivity in the detection of airways obstruction in the asthmatic and COPD groups studied.

Adult↗

PubMed1989

Trends in sexual behaviour and risk factors for HIV infection among homosexual men, 1984-7.

To assess whether the spread of infection with HIV can be reduced by changes in behaviour among groups most at risk because of their sexual practices sexual behaviour was monitored among 1050 homosexual men tested for HIV infection at a genitourinary medicine clinic in west London from November 1984 to September 1987. Four cohorts, defined by date of presentation, were studied by questionnaire at their presentation, and blood samples were analysed. Between the first and last cohorts there was a considerable fall in the proportion reporting casual relationships (291/329 (88%) v 107/213 (50%] and high risk activities, such as anoreceptive intercourse with casual partners (262/291 (90%) v 74/106 (70%], with the greatest changes occurring before the government information campaign began in 1986. Nevertheless, half of the men in the last cohort studied reported having casual partners. Multiple logistic regression showed that behavioural risk factors for HIV infection most closely resembled those for hepatitis B and that previous sexually transmitted diseases (syphilis, hepatitis B, and anogenital herpes) were themselves independent risk factors. A history of syphilis ranked above anoreceptive intercourse as the strongest predictor of HIV infection. Actively bisexual men showed a much lower prevalence of HIV infection (3/57, 5%) than exclusively homosexual men (113/375, 30%). Sexual behaviour among homosexual men changed during the period studied, and the incidence of HIV infection fell, although more education programmes directed at homosexual men are needed to re-emphasise the dangers of infection.

AIDS Serodiagnosis↗