Genetic association studies of tumour necrosis factor alpha and beta and tumour necrosis factor receptor 1 and 2 polymorphisms across the clinical spectrum of multiple sclerosis

Allelic association studies with microsatellite markers around the tumour-necrosis factor (TNF) genes have demonstrated significantly different allele distributions of TNF markers (a and b) between relapsing-remitting/secondary progressive multiple sclerosis (MS) (RR/SPMS) patients and normal controls. Considering the suspected genetic and immunological heterogeneity in MS, we tested this association in primary progressive MS (PPMS) patients. Elevated levels of serum soluble TNF receptors (sTNF-R) are reported in patients with gadolinium enhancing lesions, and animal models suggest a possible therapeutic role of sTNF-RI in MS. Thus we performed similar association studies using markers for the TNF-R genes. Gene association studies were carried out on 199-216 normal controls, 174 RR/SPMS patients and 102 PPMS patients using polymorphic dinucleotide repeat TNF markers (a, b and d), and separate markers for TNF-RI and TNF-RII. Forward primers were fluorescently labelled, polymerase chain reaction (PCR) products were analysed on a fluorescent fragment analyser, and Genescan 672 software was used for allele sizing. Samples were typed for HLA-DR antigens using PCR technology and sequence-specific oligonucleotide probes. TNFa marker allele distributions differed significantly between PPMS patients and controls (P = 0.028), largely attributable to an increase in the 118-bp TNFa allele in PPMS patients (P = 0.00024). Allele distributions were similar in PPMS and RR/SPMS patients (P = 0.91). Logistic regression analysis, however, indicated that these associations were not independent of that with HLA-DRB1*15. For the TNFb marker, the 127-bp allele showed association with both patient categories (PPMS vs. controls, P = 0.010; RR/SPMS vs. controls, P = 0.027), whilst the 128-bp allele occurred more frequently in controls (PPMS vs. controls, P = 0.036: RR/SPMS vs. controls, P = 0.0009). As with the TNFa 118 bp allele, the association with TNFb was not independent of the HLA association. No association occurred with the TNFd marker, and there were also no significant differences in allele frequencies between MS groups and controls regarding the marker for TNF-RI or TNF-RII. In Northern Irish patients the TNF contribution to MS genetic susceptibility is therefore similar across the clinical spectrum of the disease but is not independent of the association with HLA-DRB1*15.

Genotyping and functional analysis of a polymorphic (CCTTT)(n) repeat of NOS2A in diabetic retinopathy

Accumulating evidence shows that the severity and rapidity of onset of diabetic retinopathy are influenced by genetic factors. Expression of the nitric oxide synthases is altered in the retinal vasculature in the early stages of diabetic retinopathy. We analyzed the allele distribution of a polymorphic pentanucleotide repeat within the 5' upstream promoter region of the NOS2A gene in samples of diabetic patients. In diabetic patients from Northern Ireland, the 14-repeat allele of the NOS2A marker was significantly associated with the absence of diabetic retinopathy. Carriers of this repeat had 0.21-fold the relative risk of developing diabetic retinopathy than noncarriers of this allele. They also had significantly fewer renal and cardiovascular complications. The ability of differing numbers of (CCTTT)(n) pentanucleotide repeats to induce transcription of the NOS2A gene was analyzed using a luciferase reporter gene assay in transfected colonic carcinoma cells. Interleukin 1beta (IL-1beta) induction was most effective in constructs carrying the 14-repeat allele. When cells were incubated in 25 mM glucose to mimic the diabetic state, IL-1beta induction was inhibited in all cases, but to a significantly lesser extent with the 14-repeat allele. These unique properties of the 14-repeat allele may confer selective advantages in diabetic individuals, which may delay or prevent microvascular complications of diabetes.

The British Diabetic Association Cohort Study, I: all-cause mortality in patients with insulin-treated diabetes mellitus

AIMS

To assess mortality in patients with diabetes incident under the age of 30 years.

METHODS

A cohort of 23 752 diabetic patients diagnosed under the age of 30 years from throughout the United Kingdom was identified during 1972-93 and followed up to February 1997. Following notification of deaths during this period, age- and sex-specific mortality rates, attributable risks and standardized mortality rates were calculated.

RESULTS

The 23 752 patients contributed a total of 317 522 person-years of follow-up, an average of 13.4 years per subject. During follow-up 949 deaths occurred in patients between the ages of 1 and 84 years, 566 in males and 383 in females. All-cause mortality rates in the patients with diabetes exceeded those in the general population at all ages and within the cohort were higher for males than females at all ages except between 5 and 15 years. The relative risk of death (standardized mortality ratio, SMR), was higher for females than males at all ages, being 4.0 (95% CI 3.6-4.4) for females and 2.7 (2.5-2.9) for males overall, but reaching a peak of 5.7 (4.7-7.0) in females aged 20-29, and of 4.0 (3.1-5.0) in males aged 40-49. Attributable risks, or the excess deaths in persons with diabetes compared with the general population, increased with age in both sexes.

CONCLUSIONS

This is the first study from the UK of young patients diagnosed with diabetes that is large enough to calculate detailed age-specific mortality rates. This study provides a baseline for further studies of mortality and change in mortality within the United Kingdom.

The British Diabetic Association Cohort Study, II: cause-specific mortality in patients with insulin-treated diabetes mellitus

AIMS

To measure cause-specific mortality, by age, in patients with insulin-treated diabetes incident at a young age.

METHODS

A cohort of 23 752 patients with insulin-treated diabetes diagnosed under the age of 30 years, from throughout the United Kingdom, was identified during 1972-93 and followed to February 1997. Death certificates have been obtained for deaths during the follow-up period and cause-specific mortality rates and standardized mortality ratios by age and sex are reported.

RESULTS

During the follow-up period 949 deaths occurred and at all ages mortality rates were considerably higher than in the general population. Acute metabolic complications of diabetes were the greatest single cause of excess death under the age of 30 years. Cardiovascular disease was responsible for the greatest proportion of the deaths from the age of 30 years onwards.

CONCLUSIONS

Deaths in patients with diabetes diagnosed under the age of 30 have been reported and comparisons drawn with mortality in the general population. To reduce these deaths attention must be paid both to the prevention of acute metabolic deaths and the early detection and treatment of cardiovascular disease and associated risk factors.

Influence of hospital and clinician workload on survival from colorectal cancer: cohort study

OBJECTIVE

To determine whether clinician or hospital caseload affects mortality from colorectal cancer.

DESIGN

Cohort study of cases ascertained between 1990 and 1994 by a region-wide colorectal cancer register.

OUTCOME MEASURES

Mortality within a median follow up period of 54 months after diagnosis.

RESULTS

Of the 3217 new patients registered over the period, 1512 (48%) died before 31 December 1996. Strong predictors of survival both in a logistic regression (fixed follow up) and in a Cox's proportional hazards model (variable follow up) were Duke's stage, the degree of tumour differentiation, whether the liver was deemed clear of cancer by the surgeon at operation, and the type of intervention (elective or emergency and curative or palliative intent). In a multilevel model, surgeon's caseload had no significant effect on mortality at 2 years. Hospital workload, however, had a significant impact on survival. The odds ratio for death within 2 years for cases managed in a hospital with a caseload of between 33 and 46 cases per year, 47 and 54 cases per year, and >/=55 cases per year (compared to one with </=23 cases per year) were respectively 1.48 (95% confidence interval 1.03 to 2.13), 1.52 (1.08 to 2.13), and 1.18 (0.83 to 1.68).

CONCLUSIONS

There was no detectable caseload effect for surgeons managing colorectal cancer, but survival of patients treated in hospitals with caseloads above 33 cases per year was slightly worse than for those treated in hospitals with fewer caseloads. Imprecise measurement of clinician specific "events rates" and the lack of routinely collected case mix data present major challenges for clinical audit and governance in the years ahead.

Risk of Alzheimer's disease is associated with a very low-density lipoprotein receptor genotype in Northern Ireland

The epsilon-4 allele of apolipoprotein E (APOE) is associated with increased risk of Alzheimer's disease (AD), but the pathogenic mechanism is unknown. The 5-repeat allele of a CGG repeat polymorphism in the 5' untranslated region of the very low-density lipoprotein receptor (VLDL-R) gene, a receptor for apoE, has been found to be associated with increased risk of AD in a Japanese population. Other groups have been unable to replicate this in American Caucasian populations. A case-control study utilizing a clinically well-defined group of late-onset AD patients (n = 108) and age- and sex-matched control subjects (n = 108) from Northern Ireland was performed to test this association in a relatively homogeneous population. The 9,9 genotype of the VLDL-R was found to be significantly increased in patients compared to controls (P = 0.003; Pcorr = 0.035), leading to an increased risk of AD to subjects with this genotype (OR = 3.9; 95% CI, 1.52-11.25). In contrast to results from the Japanese study, the 5-repeat allele was found to be significantly reduced in the patient group when compared to controls (P = 0.008; Pcorr = 0.047). The results from this study suggest that individuals who have the 9,9 genotype of the VLDL-R gene are at increased risk of AD in Northern Ireland.

Fasting plasma glucose and subsequent macrovascular disease after 10 years follow-up: a collaborative study on two populations

The American Diabetes Association recently proposed a new, lower, cut-point of 7.0 mmol/l for diagnosis of diabetes mellitus. We examined data from the Caerphilly and Speedwell cohorts to determine possible cut-points of fasting plasma glucose for increased risk of subsequent ischaemic heart disease (IHD). Men (n = 4860) from the general population of a town in South Wales and a practice-based population in Bristol aged 45-63 years were first examined in 1979-83, and re-examined at intervals, and these data relate to follow-up at about 10 years (120 months, Caerphilly) (112 months, Speedwell). Clinically recognized diabetics (n = 94) experienced a higher mortality rate and an excess number of major IHD events. Among non-diabetics, mean blood glucose was 5.0 mmol/l and a significant excess of major IHD events occurred above this point even when the data were fully adjusted for all other IHD risk factors. Risk of major IHD was greatest for non-diabetic men with plasma glucose levels between 7.0 and 7.7 mmol/l. Under 7.0 mmol/l, the excess event rate was modest, however. Glucose levels were not associated with excess all-cause mortality among these non-diabetic men. These data, based on the excess risk of macrovascular disease experienced by a British cohort of non-diabetic men, accord with the proposals to base the diagnosis of diabetes on a cut point of 7.0 rather than 7.8 mmol/l.

Dinucleotide repeat polymorphisms in EDN1 and NOS3 are not associated with severe diabetic retinopathy in type 1 or type 2 diabetes

PURPOSE

Endothelin-1, and constitutive endothelial nitric oxide synthase, have been implicated in the pathogenesis of diabetic retinopathy. We therefore screened polymorphisms within the genes encoding these two vasoactive agents in a sample of individuals with 15 years of diabetes and no retinopathy (ETDRS level 10 or better) and those with severe retinopathy (ETDRS level 50 or worse).

METHODS

PCR primers for highly polymorphic sites within the EDN1 and NOS3 genes were used to genotype individuals with type 1 or type 2 diabetes with severe or no retinopathy. Allele frequencies were compared between groups using chi-squared analysis and adjusting for multiple comparisons.

RESULTS

No significant differences were observed in allele frequencies for these two markers between the patients who had retinopathy and the patients who did not.

CONCLUSION

Polymorphic variability in the EDN1 and NOS3 genes does not appear to have a major impact on determining susceptibility or resistance to diabetic retinopathy.

An interluekin 1B allele, which correlates with a high secretor phenotype, is associated with diabetic nephropathy

Induction of interleukin 1 activates vascular endothelial and kidney mesangial cells, and increases production of type IV (basement membrane) collagen. Hence, genes within the interleukin 1 gene cluster are potential candidates in the pathogenesis of diabetic nephropathy. In a previously validated case-control study from Northern Ireland, consisting of 95 patients with insulin-dependent (type 1) diabetes and nephropathy (cases) and 96 patients with insulin-dependent (type 1) diabetes without nephropathy (controls), the authors performed PCR-based genotyping of specific DNA polymorphisms within the interleukin 1A, interleukin 1B, interleukin 1 (type 1) receptor and interleukin 1 receptor antagonist genes. The groups were matched for age at onset and duration of diabetes. A statistically significant increase was found in the allele frequency of the interleukin 1B*2 allele in cases compared to controls (chi2=7. 19, df.=1; P=0.007, Pcorr=0.028). The results of this study suggest that the interleukin 1B*2 allele, or a susceptibility factor in linkage disequilibrium with this allele, is associated with diabetic nephropathy in the Northern Ireland population.

Scientific meaning of meanings: quests for discoveries concerning our cultural ills

This paper outlines pioneering concepts of fundamental physical and emotional features of the human brain which served as primary operators. These have developed during the past 10,000 years, giving rise to our present global megacultures and their various ancestral culture progenitors. Essential points are these: (1) Biological evolution endowed the human brain (quite inadvertently and unintentionally) with enormous latent powers for complex and sophisticated abstract ratiocinations. (2) Magnitudes of these latent powers grew exponentially with linear enlargements of brain size during the evolution of the genetic ancestors of Homo sapiens sapiens (Hss) during the past 3 million years, but these latent powers never materialized in utilized forms within the environmental contexts in which they evolved. (3) These sophisticated, abstract ratiocinations, both latent powers and operative forms in today's Hss brain, are divided between two major categories: utilitarian thinking and nonutilitarian thinking. (4) These two different types of thinking processes are carried out within separate, different regional combinations of neuronal biochemical entities within the same individual brain. (5) Sensitivities of abstract, sophisticated ratiocination processes within the human brain to influences from communication interactions with other human brains are exponentially greater in comparison with any other species of central nervous system in the earth's biosphere. This makes the brain population density the utmost critical factor, and determines the character of human thought within interacting populations of brains at a given time and place within a particular culture. (6) Abrupt increases of sedentary brain population densities, unnaturally greater by orders of magnitude than those that existed previously in biological evolutionary contexts, were engendered by the inauguration of agricultural practices 10,000 years ago. This enabled latent powers of the human brain used for complex and sophisticated abstract ratiocinations to become manifest in materialized forms of usage within relatively large groups of humans living i certain regions of the earth. (7) Thinking processes of the utilitarian category within brains living in such regions guided and dominated the development of sophisticated and complex social hierarchies and institutions, forms of communication, technologies, and cultures since that time. This dominating factor relegated thinking processes within the nonutilitarian categories of those brains to subservient roles during those developments. (8) Nonutilitarian abstracts ratiocinations possess a potential for proper adjudication and guidance of utilitarian abstract ratiocinations in the latter's development of culture. However, lack of the former's proper role in cultural developments since the beginning of the Holocene interglacial era has resulted in the imprisonment of Hss as aliens in an intellectual hell on a foreign planet.

Correlates of changes in mood following a mood induction in osteoarthritis patients

OBJECTIVE

To determine the relationship of mood management skills, and affective and cognitive states to changes in moods following mood induction among people with osteoarthritis.

METHODS

After completing questionnaires, participants underwent a negative mood induction. Momentary moods were assessed prior to, immediately following, and several minutes after the mood induction.

RESULTS

A specific mood management skill, mood clarity, consistently predicted changes in positive mood following the mood induction: people who scored high on mood clarity experienced less diminution in positive affect. In contrast, changes in negative affect were unrelated to mood management skills. However, people who scored higher on measures of depressive symptoms and pessimism rebounded from the negative induced mood less strongly than others.

CONCLUSION

Positive and negative emotional states operate largely independently and are differentially influenced by mood clarity, depressive symptoms, and pessimism. High levels of mood clarity may be adaptive in illnesses such as osteoarthritis because negative affective experiences that may be unavoidable need not preclude positive affective states.

Effect of B-group vitamins and antioxidant vitamins on hyperhomocysteinemia: a double-blind, randomized, factorial-design, controlled trial

Mild hyperhomocysteinemia is accepted as a risk factor for premature cardiovascular disease. In a population with a high prevalence of cardiovascular disease, we screened a group of clinically healthy working men aged 30-49 y (n = 509) for plasma homocysteine and 5,10-methylene tetrahydrofolate reductase (MTHFR) genotype status. Those with mildly elevated homocysteine concentrations (> or = 8.34 micromol/L) were selected for intervention. In a randomized, factorial-design, controlled trial we assessed the effects of B-group vitamins and antioxidant vitamin supplementation on homocysteine concentrations. The 132 men were randomly assigned to one of four groups: supplementation with B-group vitamins alone (1 mg folic acid, 7.2 mg pyridoxine, and 0.02 mg cyanocobalamin), antioxidant vitamins alone (150 mg ascorbic acid, 67 mg RRR-alpha-tocopherol, and 9 mg beta-carotene), B-group vitamins with antioxidant vitamins, or placebo. Intervention was double-blind. A total of 101 men completed the 8-wk intervention. When homocysteine concentrations were analyzed by group, significant (P < 0.001) decreases (32.0% and 30.0%, respectively) were observed in both groups receiving B-group vitamins either with or without antioxidants. The effect of B-group vitamins alone over 8 wk was a reduction in homocysteine concentrations of 27.9% (95% CI: 22.0%, 33.3%; P < 0.001) whereas antioxidants alone produced a nonsignificant increase of 5.1% (95% CI: -2.8%, 13.6%; P = 0.21). There was no evidence of any interaction between the two groups of vitamins. The effect of B-group vitamin supplementation seemed to depend on MTHFR genotype. Supplementation with the B-group vitamins with or without antioxidants reduced homocysteine in the men with mildly elevated concentrations, and hence may be effective in reducing cardiovascular risk.

Is metabolic syndrome a discrete entity in the general population? Evidence from the Caerphilly and Speedwell population studies

OBJECTIVE

To examine the clinical and epidemiological utility of the concepts of metabolic syndrome and insulin resistance syndrome in two prospective cohort studies of white men.

METHODS

Men aged 45-63 years were screened for evidence of ischaemic heart disease (IHD) between 1979 and 1982 and followed up at regular intervals thereafter. Non-fatal coronary events were validated from hospital records and fatal coronary events from death certificates.

RESULTS

Analysis of serum insulin concentrations in non-diabetic individuals measured at entry to the study showed no independent contribution to the prediction of subsequent IHD at 10 year follow up. Blood glucose concentrations, however, showed a small independent contribution in the combined cohort in the upper fifth of the distribution. Three different models of metabolic syndrome among non-diabetic individuals were defined based on tertiles, medians, and clusters. The predictive value of each model was assessed using logistic regression before and after adjustment for conventional and metabolic risk factors. After adjustment the odds were non-significant and close to unity.

CONCLUSIONS

This study did not detect any complex relation among the five variables defining metabolic syndrome; the excess risk seems to be no greater than can be explained by individual effects of the defining variables in a multiple logistic model.

Quantifying meaningful changes in pain

One hundred and thirty-eight nurses were asked to indicate the smallest meaningful reduction in pain from each of four hypothetical pain intensities: 100, 75, 50 and 25, on 100 mm visual analogue scales. The median values for the smallest meaningful reductions in pain were 31, 24, 18 and 10 mm, respectively, representing reductions in pain intensity of 31%, 32%, 36% and 40%, respectively. These tests were repeated in 110 patients before and after they had a lower third molar extraction under general anaesthesia. The patients' expectations of pain relief, pre- and postoperatively, were very similar to those observed in the nurses. For each of the four hypothetical pain intensities the median values for meaningful reductions in pain became greater following surgery. The pre-operative median reductions from the hypothetical pains 100, 75, 50 and 25 mm were 26, 20, 15 and 11 mm (26%, 27%, 29% and 44%), respectively. The corresponding postoperative reductions were 31, 24, 19 and 12 mm (31%, 32%, 38% and 48%). To achieve a meaningful reduction in pain postoperatively in 50% of patients it is necessary to reduce pain as represented by the visual analogue scale, by between 31 and 48%, depending on its initial intensity.

What is a safe waiting time for coronary artery bypass surgery?

To determine the factors that influenced doctors' prioritization and decisions on safe waiting time for coronary artery bypass surgery, 50 'paper patients', based on a random sample of cases who actually had surgery, were assessed by 33 clinicians. We used linear regression models to reflect the impact of clinical and non-clinical 'cues' on safe waiting time and priority decisions. The benefits of surgery tended to be over-estimated. For example, the average perceived gain in life expectancy for patients with left main-stem disease was 6.74 years. However, models incorporating only the perceptions of benefit as independent variables (i.e. the anticipated symptom reduction, MI risk reduction and life expectancy extension), had only modest explanatory power (mean R2 was 0.55 for safe waiting time, and 0.56 for priority decisions). Models which incorporated perceptions of benefit and the cases' clinical and non-clinical characteristics had generally much higher explanatory power (mean R2, 0.83 and 0.86, respectively). Lifestyle and demographic variables had much less impact on the doctors' judgements than the major clinical cues of angina severity and left main-stem stenosis. Demographic and lifestyle cues had different impacts on safe waiting time and priority for about 25% of doctors.

Tuberculosis in health service employees in Northern Ireland

Tuberculosis can be transmitted from patients to health care workers. However, where the incidence of tuberculosis is low, and good infection control practices exist, the risk of health care workers acquiring the disease is likely to be small. The objective of this study was to determine the rate of notification of tuberculosis in health care workers in Northern Ireland compared with the general population. Information from the statutory tuberculosis notification forms for the period 1982-1991 was entered on to a computer database. Those patients involved in health care occupations were identified and age and sex standardized incidence rates were calculated. The overall notification rate for tuberculosis was 7.4 cases per 100,000 of general population. There was no significant increase in notification of tuberculosis among health care workers [standardized incidence ratio: 126% (95% CI 91-170)]. No cases were diagnosed as a result of screening methods performed during employment. It was concluded that health care workers in Northern Ireland did not have a significantly increased incidence of tuberculosis compared with the general population over the 10-year period studied. This suggests that the risk of transmission from patients to health care workers is negligible in the setting of a low general incidence of tuberculosis and good infection control practice. Under these circumstances, the present findings support the cessation of routine screening of health care workers.

Rising incidence of type 1 diabetes in Scottish children, 1984-93. The Scottish Study Group for the Care of Young Diabetics

OBJECTIVES

To calculate the incidence of type 1 diabetes in Scottish children aged less than 15 years between 1984 and 1993; to examine changes in incidence; and to calculate the prevalence of diabetes at the end of this period.

DESIGN

Three data sources were used to construct the Scottish Study Group for the Care of Young Diabetics register: active reporting of all new cases; reports from the Scottish Morbidity Register 1; and local registers.

SUBJECTS

All children resident in Scotland diagnosed with primary insulin dependent diabetes mellitus when less than 15 years of age between 1984 and 1993.

MAIN OUTCOME MEASURES

Annual incidence and prevalence rate for Scotland; time trend in incidence over the 10 years; differences in incidence between the three different age groups; and completeness of the register.

RESULTS

The average annual incidence for Scotland was 23.9/100,000 children. The prevalence rate was 1.5/1000 in 1993. A total of 2326 cases was identified from the three sources. Capture-recapture analysis suggests a case ascertainment of 98.6%. The annual incidence rates increased at a rate of 2% each year (rate ratio = 1.02, 95% confidence interval (CI) 1.01 to 1.03). The incidence was higher in boys than girls (rate ratio = 1.08, 95% CI 1.00 to 1.18), and the incidence rates increased with age: 15.3/100,000/year for age 0-4 years, 24.4/ 100,000/year for age 5-9 years, and 31.9/ 100,000/year for age 10-14 years.

CONCLUSIONS

The incidence of type 1 diabetes in Scotland is increasing and the prevalence is relatively high. These findings have important implications for health service resource allocation. The Scottish Study Group for the Care of Young Diabetics' register provides a base for monitoring and research.

A field trial of an orthodontic treatment need learning package for general dental practitioners

OBJECTIVE

To evaluate whether GDPs using an index of Orthodontic Treatment Need (IOTN) learning package in a practice setting referred (or treated) more patients with a definite need for orthodontic treatment.

DESIGN

A randomised controlled trial.

SUBJECTS AND METHODS

20 GDPs (test group) used the package when selecting patients for orthodontic care during normal dental practice. A control group of 20 GDPs did not use the package. Over a 12-month period impressions were taken by the participating GDPs of all patients selected for orthodontic treatment, either referred to another practitioner or to be treated by the GDP.

MAIN OUTCOME MEASURE

IOTN used by two expert examiners.

RESULTS

Among the patients selected for orthodontic treatment by the test group there were more patients with a definite objective need for orthodontic treatment (78.1% versus 62.5% in the control group). After adjustment for potential confounding variables, the odds on a patient selected by a test group dentist being in definite need were 2.24 (95% CI 1.25, 4.01) more than the odds on a patient selected by a control group dentist (P = 0.007).

CONCLUSIONS

Use of the IOTN learning package by GDPs would reduce the proportion of patients selected for orthodontic treatment with low or moderate objective need.

Macrovascular disease and hyperglycaemia: 10-year survival analysis in Type 2 diabetes mellitus: the Belfast Diet Study

The relationship between macrovascular disease and blood glucose control in long-term follow-up of Type 2 (non-insulin-dependent) diabetes mellitus is difficult to study because of the gradual rise in fasting plasma glucose due to ongoing beta-cell failure. We used time-dependent covariates in Cox's proportional hazards model to allow variables measured annually during a 10-year prospective follow-up to be related to risk of myocardial infarction or cerebrovascular accident. Data for 432 newly diagnosed diabetic patients were available, 112 of whom suffered myocardial infarction (fatal or non-fatal). Analysis of baseline measurements only gave relative hazards (95% CL) of 1.04 (0.99, 1.09) per mmol l(-1) increase in fasting plasma glucose, 1.43 (1.12, 1.83) per decade increase in age and 1.07 (0.98, 1.17) per 10 % increase in percentage of ideal weight. Analysis incorporating ongoing measurements gave corresponding figures of 1.07 (1.02, 1.12) for fasting plasma glucose, 1.64 (1.23, 2.20) for age and 1.06 (0.95, 1.18) for percentage of ideal weight. The risk of myocardial infarction while on insulin treatment 1.09 (0.58, 2.06) or oral agents 1.41 (0.86, 2.31) was not significantly elevated relative to dietary treatment. Baseline smoking status, systolic blood pressure, and previous myocardial infarction were also significant predictors of myocardial infarction. Similar relationships were found for cerebrovascular accident and total mortality. Increasing fasting plasma glucose is a significant independent predictor of macrovascular disease in diabetes.

Do people with rheumatoid arthritis develop illness-related schemas?

OBJECTIVE

To assess, using both qualitative/inductive and quantitative data, whether people with rheumatoid arthritis (RA) have schemas related to arthritis.

METHODS

Themes identified from interview and focus group transcripts were used to develop 1) questionnaire items, and 2) statements participants were asked to recall during home interviews. Two hundred one people with RA completed questionnaires and recall tasks of the type used in cognitive research, followed 10 days later by another recall assessment by telephone.

RESULTS

Qualitative methods, item-level questionnaire data, and category-level recall data yielded convergent results supporting 4 final categories: mastery, support, loss of independence, and depression. Regression analyses indicated that category of earlier recollections predicted subsequent recollections assessed via phone.

CONCLUSIONS

Results from widely different methods offer at least partial support for arthritis schemas and suggest that the concepts identified are meaningful to patients as well as to researchers.

Fractures and phenylketonuria

Parent or self-reported history of fractures in a group of patients aged from 0.3 to 33.6 years on dietary treatment for phenylketonuria was studied by means of a questionnaire. Twenty-one of 85 patients had a history of fracture compared with 18/98 sibling controls. There was no significant difference in the lifetime risk of fracture between patients and controls (chi 2 = 1.43, df = 1, p = 0.23), but a significantly higher risk of fracture was reported over the age of 8 y (chi 2 = 5.11, df = 1, p = 0.024), with a relative risk of 2.6 (95% confidence interval 1.1.6.1). We suggest this may be related either to deterioration in dietary control in this age group or to a cumulative disease-related or diet-related reduction in bone mass.

The stated and tacit impact of demographic and lifestyle factors on prioritization decisions for cardiac surgery

In a clinical judgement analysis, we used linear regression models to reflect the impact of clinical and non-clinical cues on priority decisions, by comparing the stated prioritization policies of 30 clinicians with their actual policies as revealed by an appraisal of 50 'paper patients'. Correspondence was modest for some cues, e.g. 25 doctors said they accounted for age, but age only had a significant bearing in the derived decision models of two doctors. Correspondence between the derived and expressed weights was greatest for clinical angina grade and the presence of left main stem stenosis. Correlation between the rank order of importance between the two models was poor for most of the cues, and statistically significant only for smoking. However, stated policies made it appear that lifestyle factors such as smoking habit would influence prioritization decisions for most clinicians but policies derived from actual prioritization decisions seldom related to lifestyle or demographic variables. There were significant differences in the degree of correlation between the two models according to the experience of the clinician. However, correspondence was not significantly better for doctors with cardiological training than those without. The overall contribution of demographic and lifestyle factors to decision making appears to be small, suggesting that they should be omitted from prioritization guidelines.

The prevalence of systemic lupus erythematosus in Northern Ireland

Using six sources of patient ascertainment, 467 patients were initially identified as having a diagnosis of systemic lupus erythematosus (SLE) in Northern Ireland. The diagnosis was subsequently altered in 45 of these, either by the patient, their family, or their physician. The corrected source data were then reanalysed by the 'capture-recapture' technique, which suggested a further 71 patients missed during the initial identification process. Eighty-eight patients underwent physical examination, and 14 were found to have a diagnosis other than SLE. A final estimated figure of 415 patients was obtained, giving a point prevalence on August 1, 1993 of 25.4 per 10,000 for the Province (95% confidence interval 22.1-28.7 per 100,000).

Cutaneous malignant melanoma in Northern Ireland

The results of two 5-year studies, for 1974-78 and 1984-88, of cutaneous malignant melanoma (CMM) in Northern Ireland show changes in the presentation of the disease. Although there is some evidence of earlier diagnosis, the rise in incidence has produced an overall increase in the number of cases with advanced disease.

Epidemiology of childhood IDDM in Northern Ireland 1989-1994: low incidence in areas with highest population density and most household crowding. Northern Ireland Diabetes Study Group

During the period 1989-1994, 462 cases of insulin-dependent diabetes mellitus were registered among children from Northern Ireland aged under 15 years. The estimated completeness of the register was 98.8% (95% confidence interval (CI) 97.7%, 99.9%). A standardised rate of 19.6 (95% CI 17.8, 21.4) per 100 000 person years was obtained, placing Northern Ireland near the top of the range of published incidence in the United Kingdom, with a rate close to that reported for Scotland. In an analysis based on 217 postcode sectors, areas with a high population density and the most material deprivation were observed to have the lowest incidence rates. After inclusion of population density in a Poisson regression analysis, the component of deprivation which was found to be most significant was household crowding. Relative to children living in areas of low population density, there was a reduced risk for children in medium (relative incidence 0.85 (95% confidence limits CI 0.67, 1.09)) and high (0.62 (95% CI 0.48,0.80)) population density areas. Similarly, relative to children living in areas with low levels of household crowding, there was a reduced risk for children in medium (relative incidence 0.73 (95% CI 0.58,0.93)) and high (0.67 (95% CI 0.53, 0.83)) levels of household crowding. Tests for space-time clustering at diagnosis and at birth were negative. A possible explanation for the differences in incidence rate observed in this study is that exposure to infections very early in childhood is a protective factor. Later infections may act as either initiators or promoters of diabetes, but the absence of space-time clustering suggests that no single specific infectious agent is responsible.

Evaluation of routine ultrasound in the prenatal diagnosis of structural anomalies of the fetus

The objective of this study was to evaluate routine obstetric ultrasound in detecting fetal structural anomalies and the impact of changing clinical practice on success rates. A retrospective study of routine ultrasound in a population of 6,869 pregnancies was performed during 1985-86 (phase 1) to establish efficacy of ultrasound in the detection of fetal anomalies. Changes in ultrasound practice comprised timing, personnel and technique of fetal examination. After alterations in practice, a prospective study of 6,969 pregnancies during 1987-89 (phase 2) was performed. All abnormal fetuses (cases) were assessed in both studies. Random samples of normal infants (controls) were chosen from both populations to establish specificity. In 83 cases in phase 1,116 anomalies were diagnosed postnatally of which 11 were suspected by routine prenatal ultrasound at < 24 weeks (sensitivity 9%, 95% C.I. 4-15). In 72 cases in phase 2, 89 anomalies were identified postnatally of which 27 were suspected by routine prenatal ultrasound at < 24 weeks (sensitivity 30%, 95% C.I. 21-41). The change in sensitivity was statistically significant (p = 0.0003). Of the 382 control infants randomly selected in phase 1, false abnormal scans were not identified (specificity 100%, 95% C.I. 99-100). Of the 367 control infants in phase 2, 12 false abnormal scans were identified (specificity 96.7%, 95% C.I. 95-99). The decrease in specificity was statistically significant (p = 0.0013). The detection of urorenal and to a lesser degree central nervous system anomalies showed most improvement between the two phases. The alterations to routine ultrasound practice in timing, personnel and technique have significantly improved the detection of all fetal structural anomalies but at the cost of a small but significant loss of specificity.

Cutaneous neoplasia following PUVA therapy for psoriasis

To determine the risk of cutaneous neoplasia following photochemotherapy (PUVA), we reviewed patients with psoriasis treated at our unit between 1979 and 1991. Two hundred and forty-five patients were assessed, with a median duration of follow-up of 9.5 years. Fifty-nine per cent were male, and 41% female. The median number of exposures was 59, and the median total dose was 133 J/cm2 for the group as a whole. Non-melanoma skin cancers (NMSC) occurred in six individuals (2.4%). Basal cell carcinoma occurred in all six and one individual also developed four squamous cell carcinomas and Bowen's disease of the penis. No cases of malignant melanoma were recorded. Patients who developed NMSC received a median number of 225 exposures and a median cumulative dose of 654 J/cm2. Compared with a control study population in West Glamorgan, Wales, there was a 1.4 (95% confidence limits (CL) 0.5 and 3.1) times increased risk of NMSC. A statistically significant increased incidence of NMSC was found for patients who had received 100 or more exposures, and 250 or more J/cm2, with risks of 3.7 (95% CL 1.0 and 9.5), and 4.0 (95% CL 1.1 and 10), respectively. A PUVA dose of < 250 J/cm2 or < 100 exposures conferred a minimal increase in risk of NMSC in our study population.

Follow-up study of clinical and immunological findings in patients presenting with acute parvovirus B19 infection

This study was undertaken to examine the natural history of parvovirus B19 infection in persons without a known immune defect in terms of both clinical symptoms and immune responsiveness to the virus. Fifty-three patients with acute B19 infection (positive for serum anti-B19 IgM) were studied; symptoms at acute infection were rash and arthralgia (n = 26), rash (n = 7), arthralgia (n = 16), aplastic crisis (n = 3), and intrauterine fetal death (n = 1). Patients were followed for 26-85 months (mean 57 months) and reassessed for persistent symptoms, anti-B19 antibodies, and antibodies to the unique region of B19 VP1. There were 23 cases of arthralgia persisting for longer than 1 year after acute infection. One of these patients, a 48-year-old woman at follow-up, had had persistent arthralgia for 4 years following acute B19 infection, had rheumatoid factor at a titre of 1920 IU/ml detected at follow-up, and had been independently diagnosed as having rheumatoid arthritis at the time of follow-up. All 53 patients were positive for serum anti-B19 IgG compared to 45 of 53 age- and sex-matched control patients, a significant difference (two-tailed P value = 0.008). All test patients at follow-up and control patients were negative for serum anti-B19 IgM and antibodies to the unique region of B19 VP1. Serum from acute infection from 33 of 53 test patients was tested for antibodies to the unique region of VP1, and 16 of these were positive. The presence of this antibody did not correlate with subsequent duration of symptoms but did correlate with a short interval between symptom onset and blood sampling. The unique region of B19 VP1 is known to be crucial for a successful humoral response to the virus, and it seems that the antigenic role played by this region is important only during the acute phase of B19 infection.

Pilot study of an orthodontic treatment need learning package for general dental practitioners

This pilot study evaluated an Index of Orthodontic Treatment Need Learning Package which was developed for use by general dental practitioners. Fifty-seven dentists participated in a randomised controlled trial which involved assessing the need for orthodontic treatment among two representative samples of 16 study casts. All the dentists assessed the first set of study casts without any aids or assistance. During the assessment of the second set of study casts one group of dentists used an IOTN Learning Package in the form of a poster, another group used an IOTN Learning Package in the form of a booklet, and the remaining group acted as a control and did not use any Learning Package. The results reveal that compared with the control dentists, the dentists using the IOTN poster and the IOTN booklet had, respectively, 1.8 and 2.6 fewer errors when assessing aesthetic need and 2.0 and 2.1 fewer errors when assessing dental health need.

Autres pays, autres coeurs? Dietary patterns, risk factors and ischaemic heart disease in Belfast and Toulouse

The WHO MONICA project monitors trends and determinants in cardiovascular disease to relate classical risk factor changes to trends in incidence rates. The Belfast and Toulouse MONICA centres have also collaborated in dietary studies. Both centres have validated incidence and attack rates for ischaemic heart disease using coronary event registration. These data confirm that the disease in middle-aged men is between three and four times as common in Belfast as in Toulouse. Risk factor surveys show some differences between the centres, but the overall risks assessed by two multiple logistic function scoring systems were identical. A weighed dietary survey revealed no important difference in macronutrient intake, although carbohydrate and saturated fat intake in Belfast was significantly higher. Protein, dietary cholesterol and polyunsaturated fat, particularly linoleic acid intake, was significantly higher in Toulouse, as was consumption of wine, cheese, fruit and vegetables, but not potatoes. The Northern Irish diet is typically Northern European, but although the diet in Toulouse has some features of the Mediterranean diet, it is not appreciably different from that in Belfast in terms of total fat intake. Major differences are present for several food items, and in general these differences add support to the antioxidant hypothesis.

Paediatric consultation patterns in general practice and the accident and emergency department

The age, sex, source of referral and diagnosis of children brought to a paediatric accident and emergency department by their parents were compared to those consulting their general practitioner. A simultaneous, prospective review of these consultations was carried out over a six-week period in an inner-city paediatric teaching hospital and a group practice in a socially deprived urban area. 730 children less than 13 years of age who presented for a new consultation were seen. 629 (86%) presented initially to the general practitioner, who dealt with all but 25 (4.0%) without onward referral to the accident and emergency department. 127 consultations took place at the accident and emergency department, of which 104 (82%) were parental referrals. There was no sex difference in children seen by the general practitioner. There was a decreasing trend with increasing age in the proportion of children who consulted the general practitioner, perhaps due to the higher frequency of injury in the older children. Over three quarters (77%) of injured children were brought directly to the accident and emergency department, compared with only 4% of children without injuries (p < 0.001). Of 22 children with injuries who presented to the general practitioner, only 4 (18%) required onward referral. General practitioners met the great majority of the paediatric workload generated by the practice. Audit between primary and secondary care gives a more reliable picture than data from only one source. Injured children are more likely to be taken to the accident and emergency department. Further study of the severity of injury in children is required to determine if there is potential to reduce parental referrals to accident and emergency departments.

High incidence of congenital dislocation of the hip in Northern Ireland

To determine the incidence of congenital hip dislocation (CDH) a retrospective study was carried out of cases occurring in a defined population using multiple information sources. Of 138,600 children born in the period 1983-1987, a total of 243 were diagnosed with CDH, defined as those requiring splintage or surgery whose treatment extended beyond 6 months of age. Incidence and estimates of relative risks for pre-disposing factors were determined. The rate was 1.75 cases per 1000 livebirths. Major risk factors were female gender and breech presentation. The proportions of cases identified before 1, 3 and 6 months of age were 8, 14 and 35%, respectively. Despite using a restrictive definition, we have obtained an incidence rate among the highest reported in any United Kingdom population. Early detection is widely accepted as desirable, but neonatal screening has proved ineffective.

Jass' classification revisited

BACKGROUND

In 1986, Jass and colleagues claimed to have improved on Dukes' classification of prognosis for carcinoma of the colon and rectum. To have clinical relevance, such results should be reproducible and confirmed by other institutions.

STUDY DESIGN

Retrospective clinicopathologic study of 312 carcinomas of the colon and rectum to determine whether or not Jass' classification is superior to that of Dukes' as assessed by their relative reproducibility and prognostic significance.

RESULTS

Dukes' classification had excellent intraobserver and interobserver reproducibility (kappa values of 0.86 and 0.93, respectively). In contrast, the reproducibility of variables assessed by Jass showed only slight to fair agreement (lymphocytic infiltration: intraobserver and interobserver kappa values of 0.08 and 0.05, respectively, growth pattern: intraobserver and interobserver kappa values of 0.37 and 0.41, respectively). Dukes' stage and patient age were the most important prognostic variables on multivariate regression analysis. Tumor differentiation, nuclear polarity, tubule configuration, and lymphocytic infiltration remained significantly related to survival in the presence of Dukes' stage and age. The model which best predicted prognosis was a combination of Dukes' stage, patient age and tumor differentiation. Further addition of the variables assessed by Jass to this model did not significantly improve the prediction of prognosis.

CONCLUSIONS

Dukes' classification is of greater prognostic value and more reproducible than the components of Jass' classification. The continued use of Dukes' classification is, therefore, warranted for prognostic and therapeutic decisions in patients with carcinoma of the colon and rectum.

A case-control investigation of perinatal risk factors for childhood IDDM in Northern Ireland and Scotland

OBJECTIVE

To identify perinatal risk factors for childhood insulin-dependent diabetes mellitus (IDDM) and determine if they differ between early-onset and late-onset disease.

RESEARCH DESIGN AND METHODS

We selected 258 diabetic children in Northern Ireland and 271 diabetic children in Scotland from population-based registers. For each diabetic child, five matched control subjects were drawn from the same population. All perinatal data were recorded routinely at birth. Odds ratios (ORs) were estimated for parental age, social class, breast-feeding, deprivation measures, and other perinatal variables.

RESULTS

Scottish data indicated an increased risk among children born to older mothers (OR = 2.43, 95% confidence interval [CI] 1.49-3.97 for mothers > or = 35 years of age relative to those < 25 years of age). Northern Ireland data showed no such effect. Only Northern Ireland data showed an excess risk in children of professional or managerial families (OR = 1.51, 95% CI 1.11-2.04). A small but nonsignificant reduction in risk among breast-fed children was observed only after adjustment for social class (OR = 0.76, 95% CI 0.54-1.07). Deprivation measures were associated with reductions in risk. Children delivered by cesarean section were at increased risk in both Northern Ireland (OR = 1.66, 95% CI 1.10-2.50) and Scottish (OR = 1.70, 95% CI 1.12-2.59) data. In Northern Ireland data only, children of first pregnancies were at increased risk (OR = 1.41, 95% CI 1.03-1.93). Both data sets indicated that a first pregnancy was a more important risk factor for early-onset disease than for late-onset disease.

CONCLUSIONS

Many reported risk factors are weak and show inconsistencies between studies. They may be secondary to more direct, as-yet-undiscovered risk factors. Although irrelevant in the majority of cases, the increased risk associated with delivery by cesarean section deserves further study.

Colorectal carcinoma: importance of clinical and pathological factors in survival

A series of clinicopathological variables was assessed on 312 patients undergoing surgical resection for primary colorectal cancer. Although the presence of venous invasion was related to mortality (P = 0.02), classifying invasion into involvement of thick-walled or thin-walled veins did not produce a variable of prognostic value. Intestinal obstruction (P = 0.04) and the macroscopic appearance of the tumour (P = 0.04) were related to mortality from colorectal cancer, but not from all causes of death. Duke's stage, increasing patient age and poorly differentiated tumours were the variables which were individually most significantly related to poor prognosis (P < 0.001 for each analysis). Cox's regression analysis identified these three variables as independent predictors of outcome in colorectal cancer. This study confirms that Duke's stage, patient age and tumour differentiation are still the most important clinicopathological variables in colorectal cancer.

DNA densitometry of colorectal cancer

DNA analysis was assessed by densitometry for 281 cases of colorectal adenocarcinoma. Detection of aneuploidy in a single case rose from 65% if one, to 92.5% when three or more sections, were analysed. Although aneuploid tumours had significantly larger nuclear areas than near diploid tumours (p = 0.009), densitometric measurements showed no association with clinicopathological variables. DNA content determined by densitometry was compared with that from flow cytometry on 465 tissue sections from 241 cases. Aneuploidy assessed by flow cytometry was significantly associated with that determined by densitometry (p < 0.01 for all comparisons), ploidy state being similar in 381 sections (82%, kappa = 0.63, p < 0.001), and 187 cases (77.6%, kappa = 0.57, p < 0.001). Univariate survival analysis showed that DNA densitometric variables had no significant association with survival in (a) all cases, (b) cases without lymph node metastases, or (c) cases without distant metastases. Multivariate regression analysis of densitometric and clinicopathological variables identified Dukes's stage, patient age, and tumour differentiation as the combination of variables most closely related to survival. Densitometric measurement of DNA content could not significantly improve on the prognostic model containing these three variables. It is concluded that, although the assessment of DNA content by densitometry is comparable with that of flow cytometry, conventional histological variables remain the best predictors of prognosis in colorectal cancer.

The role of flow cytometry in carcinoma of the colon and rectum

Flow cytometry was performed upon 312 patients with adenocarcinoma of the colon and rectum, satisfactory results being obtained with 275 (108 diploid, 130 aneuploid and 37 tetraploid). The proportion of nondiploid instances increased from 28 percent if one, to 80 percent when six specimens were assessed per patient. Reproducibility of the technique showed substantial agreement in the assessment of deoxyribonucleic acid ploidy (Kappa value equals 0.74). Increasing values of cells in the diving (G2/M) phase of the cell cycle were associated with little lymphocytic tumor infiltration (p = 0.0002) and extensive tumor fibrosis (p = 0.003). Univariate survival analysis revealed that, although diploid tumors tended to have a better prognosis than nondiploid tumors (p = 0.06), no flow cytometric variable was significantly related to survival. Flow cytometry similarly was not of prognostic value in instances without lymph node metastases or without distant metastases. Multivariate regression analysis of flow cytometric and clinicopathologic variables identified Dukes' stage, patient age and tumor differentiation as the combination of variables most closely related to survival. No flow cytometric variable could significantly improve on the prognostic model containing these three variables. It is concluded that conventional histologic variables remain the best predictors of prognosis in carcinoma of the colon and rectum.

Multicentre randomised trial comparing high and low dose surfactant regimens for the treatment of respiratory distress syndrome (the Curosurf 4 trial)

A randomised trial was conducted in 82 centres using the porcine surfactant extract, Curosurf, to compare two regimens of multiple doses to treat infants with respiratory distress syndrome and arterial to alveolar oxygen tension ratio < 0.22. Infants were randomly allocated to a low dosage group (100 mg/kg initially, with two further doses at 12 and 24 hours to a maximum cumulative total of 300 mg/kg; n = 1069) or a high dosage group (200 mg/kg initially with up to four further doses of 100 mg/kg to a maximum cumulative total of 600 mg/kg; n = 1099). There was no difference between those allocated low and high dosage in the rates of death or oxygen dependency at 28 days (51.1% v 50.8%; difference -0.3%, 95% confidence interval (CI) -4.6% to 3.9%), death before discharge (25.0% v 23.5%; difference -1.5%, 95% CI -5.1% to 2.2%), and death or oxygen dependency at the expected date of delivery (32.2% v 31.0%; difference -1.2%, 95% CI -5.2% to 2.7%). For 14 predefined secondary measures of clinical outcome there were no significant differences between the groups but the comparison of duration of supplemental oxygen > 40% did attain significance; 48.4% of babies in the low dose group needed > 40% oxygen after three days compared with 42.6% of those in the high dose group. The total amount of surfactant administered in the low dose regimen (mean 242 mg phospholipid/kg) was probably enough to replace the entire pulmonary surfactant pool. Adopting the low dose regimen would lead to considerable cost savings, with no clinically significant loss in efficacy.

Reduction in the risk of bronchopulmonary dysplasia from 1980-1990: results of a multivariate logistic regression analysis

A retrospective analysis (1980-1990) of normally formed low birthweight (< 2500 g) infants surviving to at least 28 days following intermittent positive pressure ventilation (IPPV) for longer than 12 h was performed. Bronchopulmonary dysplasia (BPD) was defined as oxygen dependency at 28 days with characteristic radiographic findings. Logistic regression analysis of risk factors, before and after the initiation of IPPV was performed on 412 infants. Decreasing birth weight (BW) and gestational age (GA) were associated with an increased risk of BPD. When controlled for these variables, predictive factors prior to IPPV were gender, age at IPPV, respiratory diagnosis, and year of birth. Following IPPV, duration of peak inspiratory pressure > 25 cm H2O, duration of fraction of inspired oxygen (FiO2) > 0.60 (DO2), maximum peak inspiratory pressure (MPIP), maximum FiO2, patent ductus arteriosus, bacteraemia and either pneumothorax or pulmonary interstitial emphysema were associated with an increased risk of BPD. Adjusting for BW and GA, there was a significant reduction in BPD risk from 1980-1990 (relative odds of 0.88 for each year compared to the previous year). This trend could be largely accounted for by decreases in MPIP and DO2 during the study period. Surfactant treatment was not independently associated with a significant change in the risk of BPD. Based on this analysis, we developed a scoring system for predicting the risk of BPD in the neonatal period which we evaluated in a random sample of infants. This predicted infants at risk of BPD with a sensitivity of 65% and a specificity of 88%.(ABSTRACT TRUNCATED AT 250 WORDS)

Sleep related hypoxaemia in hypertensive and normotensive men

BACKGROUND

An association between hypertension and obstructive sleep apnoea (OSA) has been found by some researchers but remains controversial. Since such an association would have important implications for the investigation and management of hypertension, the rate of nocturnal hypoxaemic episodes has been compared in hypertensive and normotensive men.

METHODS

The study was carried out in the community in Belfast and its environs. Thirty four men with mild to moderate hypertension aged 40-64 years were identified from general practice and a hypertension clinic. Normotensive men, matched for age and body mass index, were selected from a community survey. Subjects answered a sleep questionnaire and underwent overnight pulse oximetry at home. Computer analysis of the results gave the number and magnitude of dips in oxygen saturation (SaO2 dips, 4% or greater).

RESULTS

The median number of SaO2 dips/hour for hypertensives was 2.0, and for normotensives was 0.8. Lowest SaO2 and mean SaO2 levels were significantly lower in the hypertensive group. Only one subject had a rate of SaO2 dips/hour greater than five and symptoms suggestive of OSA.

CONCLUSIONS

Both hypertensive and normotensive men had relatively few episodes of nocturnal hypoxaemia. The small increase in the rate of SaO2 dips in hypertensive subjects has not yet been fully explained. These results imply that OSA is not common in hypertensive subjects and is unlikely to be an important cause of hypertension.

Morphometric analysis of colorectal cancer

Thirteen nuclear and cellular morphometric variables were measured in 312 cases of colorectal adenocarcinoma. All variables, except nuclear shape factors, differed significantly (P < 0.001) between normal colorectal and tumor tissue. In adenocarcinomas, epithelial nuclei in well-differentiated mucosa tended to be elliptic, while those in poorly differentiated mucosa were more spheric. Increasing values of maximum nuclear and elliptic diameter were associated with progression from none to simple tubule configuration (P < 0.001), none to easily discerned nuclear polarity (P < 0.001), and expanding growth pattern (P < 0.001). Univariate survival analysis revealed that none of the morphometric variables was significantly related to patient survival. Multivariate regression analysis showed that no morphometric variable could add significantly to a model containing the variables of patient age, Dukes stage, and tumor differentiation. Morphometry may be useful in distinguishing malignant from normal tissue and degrees of differentiation, but it is of little prognostic value in colorectal adenocarcinoma.

Synergistic interaction between midazolam and propofol

We gave either midazolam or propofol for induction of anaesthesia to 140 ASA I or II female patients (18-60 yr). ED50 values were obtained by probit analysis for three clinical end-points: loss of response to command; loss of eyelash reflex; failure to respond to application of an anaesthetic face mask delivering 1% isoflurane. Propofol ED50 values (95% confidence intervals) were 1.25 (0.99-1.48) mg kg-1, 1.61 (1.29-1.94) mg kg-1 and 1.51 (1.20-1.82) mg kg-1, respectively. ED50 values for midazolam were 0.26 (0.20-0.37) mg kg-1, 0.29 (0.23-0.47) mg kg-1 and 0.25 (0.20-0.32) mg kg-1, respectively. An additional 92 similar patients received one of nine dose combinations of midazolam and propofol for induction of anaesthesia, propofol being administered 2 min after midazolam. Success of induction was based on the clinical end-point of loss of response to command. Administration of 25% of the ED50 of midazolam followed by 50% of the ED50 of propofol resulted in loss of response to command in 50% of patients, while 50% of the ED50 of midazolam, followed by 25% of the ED50 of propofol had the same effect. A probit regression model specifying a synergistic interaction between midazolam and propofol fitted the data significantly better than a model specifying no interaction.

Serum copper and zinc in random samples of the population of Northern Ireland

Serum copper and zinc concentrations (mumol/L) were measured in nonfasting subjects aged 25-64 y participating in two independent population surveys in Northern Ireland. In 1983-84, copper in 1144 males was 17.2 +/- 3.1 (mean +/- SD) and zinc was 12.1 +/- 1.7 (SD). Copper in 1055 females, neither pregnant nor taking estrogens or progestogens, was 19.0 +/- 3.9 and zinc was 11.6 +/- 1.4. In 1986-87 copper in 1142 males was 17.9 +/- 3.3 and zinc was 13.2 +/- 2.1. Copper in 1034 females was 20.1 +/- 3.9 and zinc was 12.7 +/- 2.0. Zinc but not copper concentrations decreased from early morning to late afternoon; both were unaffected by reported postprandial time. There was a positive relationship between copper and age for both sexes but zinc showed only a slight upward trend with age. A positive relationship between copper and the aggregation of classical risk factors for coronary heart disease was demonstrated.