The relationship between lower limb symptoms and superficial and deep venous reflux on duplex ultrasonography: The Edinburgh Vein Study

BACKGROUND

Previous work from this group has demonstrated the relationships between lower limb symptoms and the presence and severity of trunk varicose veins as seen on clinical examination to be generally weak, symptom specific, and gender dependent.

OBJECTIVE

This study was undertaken to investigate the relationships in the general population between lower limb symptoms and the presence of superficial or deep venous reflux.

METHODS

A cross-sectional study was made of an age-stratified random sample of 1566 subjects (699 men and 867 women) aged 18 to 64 selected from 12 general practices in Edinburgh, Scotland. Subjects completed a self-administered questionnaire regarding symptoms (heaviness/tension, a feeling of swelling, aching, restless legs, cramps, itching, tingling) and underwent duplex ultrasound examination of the superficial and deep venous systems of both legs. Reflux of 0.5 seconds or greater was considered pathologic. Deep venous reflux was defined as reflux in at least the popliteal vein.

RESULTS

There was a significant positive relationship between isolated superficial reflux and the presence of heaviness/tension (P <.025, both legs) and itching (P =.002, left leg) in women. Isolated superficial reflux in men was not significantly positively associated with any symptom. Isolated deep venous reflux was not significantly related to any symptom in either leg in either sex. Combined reflux was related to a feeling of swelling (P =.018, right leg; P =.0022, left leg), cramps (P =.0049, left leg) and itching (P =.0043, left leg) in men, and aching (P =.03, right leg) and cramps (P =.026, left leg) in women.

CONCLUSION

In the general population, only certain lower limb symptoms were related to the presence of reflux on duplex ultrasound scanning. The strongest relationships were observed in the left legs of men with combined superficial and deep reflux.

Impact of professionalism on injuries in rugby union

OBJECTIVES

To measure the frequency and nature of injuries occurring in competitive matches since professionalism was introduced in rugby union.

METHODS

The cohort study previously conducted in players from senior rugby clubs in the Scottish Borders in 1993-1994 when rugby union was an entirely amateur sport was repeated in 1997-1998. The same injury definition, outcome criteria, and method of calculating playing hours were used. In total, 803 (84%) of 960 eligible players participated, including all 30 adult players who played professionally for the Scottish Rugby Union or Border Reivers District. The 576 injury episodes in 381 of these players in competitive matches were compared with the 373 injuries in 266 players out of 975 (94%) who were eligible and registered with the same senior rugby clubs in 1993-1994. Outcomes were the occurrence of injury episodes, days away from playing or training for rugby, and time lost to employment or attendance at school/college as a consequence of being injured.

RESULTS

The proportion of players who were injured almost doubled from 1993-1994 to 1997-1998, despite an overall reduction of 7% of the playing strength of participating clubs. Period prevalence injury rates rose in all age specific groups, particularly in younger players. This translated into an injury episode every 3.4 matches in 1993-94, rising to one in every 2.0 matches in 1997-1998. An injury episode occurred in a professional team for every 59 minutes of competitive play. Professional players sustained a higher proportion of recurrent injuries, particularly in the early part of the season. Some 56% of all their days lost to the game were caused by injuries to the muscles, ligaments, and joints of the knee, hip, and thigh.

CONCLUSIONS

The introduction of professionalism in rugby union has coincided with an increase in injuries to both professional and amateur players. To reduce this, attention should be focused on the tackle, where many injuries occur. The International Rugby Board should place a moratorium on the use of protective equipment in competitive matches until its contribution to player morbidity has been fully assessed.

Tissue plasminogen activator and leucocyte elastase as predictors of cardiovascular events in subjects with angina pectoris: Edinburgh Artery Study

AIMS

To evaluate the relationship between haemostatic and rheological factors and cardiovascular outcome in subjects with angina pectoris in the general population.

METHODS AND RESULTS

Two hundred and seven men and women aged 55-74 had evidence of angina at baseline. Sixty-seven (32.3%) had a fatal or non-fatal cardiovascular event during follow-up. Median levels of tissue plasminogen activator antigen and leucocyte elastase were higher in the event group compared with the no event group (10.0 ng. ml(-1)vs 7.2 ng. ml(-1);P</=0.001, and 40.3 ng. ml(-1)vs 31.0 ng. ml(-1);P</=0.01, respectively). Whole blood viscosity was also significantly higher in the event group than in the no event group (3.80 mPa.s vs 3.53 mPa.s;P</=0.05). After adjusting for age and sex, unit increases in both tissue plasminogen activator antigen and leucocyte elastase levels were significantly associated with an increased risk of a cardiovascular event. These associations remained after further adjusting for cardiovascular risk factors and baseline myocardial infarction. The relative risks were 2.07 (95% CI, 1.30-3.45;P</=0.01) for tissue plasminogen activator antigen and 1. 95 (95% CI, 1.12-3.50;P</=0.05) for leucocyte elastase.

CONCLUSION

Disturbed fibrinolysis and activation of leucocytes may be implicated in the development of thrombotic cardiovascular events in subjects with angina pectoris in the general population.

A hospital led promotion campaign aimed to increase bicycle helmet wearing among children aged 11-15 living in West Berkshire 1992-98

OBJECTIVES

To evaluate the effect of a bicycle helmet promotion campaign on helmet wearing among cyclists less than 16 years of age from 1992-98.

SETTING

Reading, West Berkshire, UK.

METHODS

A hospital led bicycle helmet promotion campaign targeted at 5-15 year olds. The campaign focused on education with active involvement of the children, parents, schools, and safety organisations. Local media and children's celebrities raised the profile of the campaign and a low cost helmet purchase scheme was also set up. A self administered questionnaire survey of 3,000, 11-15 year olds was carried out over the period of the campaign. A control group of 3,000 teenagers was obtained from a neighbouring area without a helmet campaign. Accident and emergency (A&E) figures were obtained from the local hospital within the campaign area on all children aged under 16 years, attending with bicycle injuries. Unfortunately, no figures were available from the A&E department in the control area.

RESULTS

Self reported helmet use among 11-15 years olds living in the campaign area increased from 11% at the start of the campaign to 31% after five years (p<0.001), with no change in the control group. Hospital casualty figures in the campaign area for cycle related head injuries in the under 16 years age group, fell from 112.5/100,000 to 60.8/100,000 (from 21.6% of all cycle injuries to 11.7%; p<0.005).

CONCLUSIONS

This hospital led community bicycle helmet promotion campaign directed at young people showed an increase in the number of children reporting that they "always" wore their helmet while cycling. There was a significantly higher rate of helmet wearing than in the control area, and a significant reduction in head injuries.

Increase in prevalence of obesity and diabetes and decrease in plasma cholesterol in a central Australian aboriginal community

OBJECTIVE

To document change in prevalence of obesity, diabetes and other cardiovascular disease (CVD) risk factors, and trends in dietary macronutrient intake, over an eight-year period in a rural Aboriginal community in central Australia.

DESIGN

Sequential cross-sectional community surveys in 1987, 1991 and 1995.

SUBJECTS

All adults (15 years and over) in the community were invited to participate. In 1987, 1991 and 1995, 335 (87% of eligible adults), 331 (76%) and 304 (68%), respectively, were surveyed.

MAIN OUTCOME MEASURES

Body mass index and waist: hip ratio; blood glucose level and glucose tolerance; fasting total and high density lipoprotein (HDL) cholesterol and triglyceride levels; and apparent dietary intake (estimated by the store turnover method).

INTERVENTION

A community-based nutrition awareness and healthy lifestyle program, 1988-1990.

RESULTS

At the eight-year follow-up, the odds ratios (95% CIs) for CVD risk factors relative to baseline were obesity, 1.84 (1.28-2.66); diabetes, 1.83 (1.11-3.03); hypercholesterolaemia, 0.29 (0.20-0.42); and dyslipidemia (high triglyceride plus low HDL cholesterol level), 4.54 (2.84-7.29). In younger women (15-24 years), there was a trembling in obesity prevalence and a four- to fivefold increase in diabetes prevalence. Store turnover data suggested a relative reduction in the consumption of refined carbohydrates and saturated fats.

CONCLUSIONS

Interventions targeting nutritional factors alone are unlikely to greatly alter trends towards increasing prevalences of obesity and diabetes. In communities where healthy food choices are limited, the role of regular physical activity in improving metabolic fitness may also need to be emphasised.

Methylene tetrahydrofolate reductase (MTHFR) and nitric oxide synthase (ecNOS) genes and risks of peripheral arterial disease and coronary heart disease: Edinburgh Artery Study

Hyperhomocysteinaemia and reduced nitric oxide synthesis may each result in endothelial dysfunction predisposing to atherogenesis. Genetic variants of methylene tetrahydrofolate reductase (MTHFR) and endothelial nitric oxide synthase (ecNOS) influence homocysteine metabolism and nitric oxide synthesis, respectively and might thus be determinants of the risk of atherosclerotic disease. The aim of our study was to identify, in a general population sample, the risks of peripheral arterial disease and of coronary heart disease related to MTHFR (175;198) and ecNOS (4;5) polymorphisms. In the Edinburgh Artery Study, which is a population based cohort study, 940 men and women aged 60-79 years, who had previously been selected at random from the general population, had DNA extracted from a venous blood sample. Based on a clinical examination at baseline and follow up investigations, three groups of subjects were identified: those with peripheral arterial disease (n=80), those with coronary heart disease (n=137), and healthy controls who had no evidence of cardiovascular disease (n=300). The distributions of the ecNOS and MTHFR genotypes did not differ significantly between the groups with and without cardiovascular disease. However, the ecNOS-4 allele (frequency 0.13) was related to the occurrence of coronary heart disease in non smokers, OR=2.47 (95% CI [1.42, 4.34], P=0.02). No association was found with peripheral arterial disease. The MTHFR-175 allele (frequency 0.31) was not related to coronary heart disease, but was associated with a reduced risk of peripheral arterial disease, OR=0.54 (95% CI [0.32, 0.90], P=0.02). Neither the ecNOS-4 allele or MTHFR-175 allele was related to the ankle brachial pressure index in the whole study population. In conclusion, the ecNOS-4 allele was associated with a slightly increased risk of coronary heart disease in non-smokers, but otherwise the MTHFR and ecNOS genotypes appeared to have little influence on the risks of peripheral arterial disease and coronary heart disease in this older population.

Elevated levels of soluble tumor necrosis factor receptors are associated with increased mortality rates in patients who undergo operation for ruptured abdominal aortic aneurysm

PURPOSE

Elevated levels of soluble tumor necrosis factor receptors (sTNF-Rs) are associated with multiple organ failure and increased mortality rates in critically ill patients. Paradoxically, experimental data suggest exogenous sTNF-Rs may improve outcome in patients who undergo elective abdominal aortic aneurysm (AAA) repair. This study examines, for the first time, changes in sTNF-R levels during repair of ruptured and nonruptured AAA.

METHODS

Sixteen patients who underwent surgical procedures for ruptured AAA and 10 patients who underwent surgical procedures for nonruptured AAA were studied. Levels of sTNF-Rs p55 and p75 were measured before the operation and immediately before and 5 minutes, 6 hours, and 24 hours after aortic clamp release.

RESULTS

When compared with nonruptured AAA, levels of sTNF-R p55 were significantly higher in ruptured AAA 5 minutes (P <.02) and 24 hours after aortic clamp release (P <.05). Levels of sTNF-R p75 were significantly higher in ruptured AAA before (P <.05), during (P <.001), and after the surgical procedure (P <.01). Six hours after aortic clamp release, sTNF-R p75 levels were significantly higher in nonsurvivors of ruptured AAA when compared with survivors (P <.05) and patients who underwent surgical procedures for nonruptured AAA (P <.01).

CONCLUSION

Ruptured AAA repair is associated with increased sTNF-R expression. Furthermore, elevated levels of sTNF-R p75 are associated with increased postoperative mortality rates.

Ultrasonic measurement of abdominal aortic aneurysm wall compliance: a reproducibility study

PURPOSE

The purpose of this study was to examine the intraobserver and interobserver error associated with ultrasonic echo-tracking compliance measurement in patients with abdominal aortic aneurysm.

METHODS

Two observers independently measured brachial blood pressure by sphygmomanometer and maximum aortic diameter, pressure strain elastic modulus (Ep) and stiffness using an ultrasonic echo-tracker. The observer was blind to several variables: pulse pressure, diameter change, Ep, and stiffness. In study 1, observer A measured compliance in 13 patients at 30 to 60 minutes apart. In study 2, observers A and B each measured compliance on 23 patients at two visits, 2 weeks apart.

RESULTS

There were no significant differences within observer A's compliance measurements. The coefficients of variation of method error (CV(ME)) for directly measured variables were systolic blood pressure, 7.3%; diastolic blood pressure, 5.4%; and maximum aortic diameter, 2.6%. CV(ME) values for derived variables were Ep, 21.2%, and stiffness, 17.6%. No differences were found between observers A and B and visits 1 and 2. CV(ME) values were 7.9% or less for directly measured variables and 32.7% or less for derived variables. These CV(ME) values were greatly reduced when the calculation was made with the use of log transformed data.

CONCLUSION

The high CV(ME) value for derived variables is largely due to their wide variation within this population. This technique can measure abdominal aortic aneurysm diameter and compliance with an acceptable level of intraobserver and interobserver error.

Influence of high-density lipoprotein cholesterol and rheological factors on the sex difference in cardiovascular disease

BACKGROUND

It is well established that the incidence of cardiovascular disease among men is higher than that among women.

OBJECTIVE

To determine whether differences between men and women in terms of a range of conventional and rheological risk factors could explain this sex difference.

DESIGN

This was a population-based cohort study (the Edinburgh Artery Study).

METHODS

Men and women aged 55-74 years (n = 1592) were selected at random from the general population of Edinburgh and followed up for 5 years. Baseline cardiovascular risk factors were measured and related to incidence of disease among men and women.

RESULTS

Men had higher levels of cigarette smoking, haematocrit and blood viscosity and lower levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and plasma fibrinogen than did women. The incidences of cardiovascular events among men and women were 48.3 and 26.1 per 1000 person-years, respectively. Adjustment for level of HDL cholesterol reduced the male:female ratio for sex-specific incidence rates of cardiovascular events from 1.80 [95% confidence interval (CI) 1.43-2.27] to 1.34 (95% CI 1.04-1.73). This reduction was partially reversed after further adjustment for the other cardiovascular risk factors. The impact of blood viscosity, plasma viscosity and plasma level of fibrinogen on the risk of cardiovascular disease was higher for men than it was for women (multivariate relative risk for blood viscosity were 1.24, 95% CI 1.08-1.43, for men and 0.81, 95% CI 0.61-1.06, for women).

CONCLUSIONS

Levels of HDL cholesterol levels in women being higher than those in men may explain some, but not all, of the sex difference in incidence of cardiovascular disease. Greater susceptibility of men to rheological factors might also be important.

The influence of environmental factors on rugby football injuries

The aim of this study was to establish the influence of weather and pitch conditions on the frequency and nature of rugby injuries. Observers at 26 senior rugby clubs in the Borders District of the Scottish Rugby Union reported all injuries to 1169 (96%) registered players at Saturday home and away matches during the 1993-94 season (August 1993 to April 1994). Weather and pitch conditions at 112 grounds were recorded on 605 occasions; 1268 Borders teams played at these grounds, with 344 injury episodes being sustained. Matches were played in dry weather for three-quarters of these occasions. There was a moderate association between weather and the state of the pitch (Spearman's rank correlation, r = -0.46, P < 0.001), with heavier pitches occurring in wetter weather. Logistic regression revealed that there were significant month-of-season (P = 0.003), wind strength (P = 0.008) and temperature (P = 0.011) effects on the risk of injury. On four of five occasions when matches were played in a downpour of rain, at least one injury episode occurred. Our results show that the month of the season and the weather may influence the occurrence of rugby injuries, but that the state of the pitch does not. Further studies are required to investigate these factors in more detail.

Investigation of factors which might indicate susceptibility to particulate air pollution

OBJECTIVES

To determine whether previous symptoms or recognized risk factors of cardiovascular ill health, are associated with an increased likelihood of adverse health effects related to particulate air pollution.

METHODS

Cardiovascular event rates were studied relative to urban concentrations of particulate air pollution and baseline risk factors. The Edinburgh artery study consisted of a cohort of 1592 subjects aged 55-74 and was followed up to the end of March 1998 for a median of 10 years resulting in about 5 million person-days of observation. Baseline measurements included plasma fibrinogen and blood and plasma viscosity. A nested case-control approach was used to investigate a possible interaction between effects of these selected baseline risk factors and particulate air pollution, on subsequent event rates.

RESULTS

During the follow up period there were 343 fatal and non-fatal myocardial infarctions or strokes. Trends in adverse cardiovascular outcomes related to pollution were identified among subjects belonging to the highest baseline quintile of plasma fibrinogen. Evidence for interactions between concentrations of particulate pollution and fibrinogen was not established at conventional levels of significance.

CONCLUSIONS

People with high concentrations of plasma fibrinogen might be more susceptible to adverse cardiovascular effects of particulate air pollution, but limitations of power mean that evidence relating to such an interaction is not conclusive. A range of cardiopulmonary risk factors warrant investigation in relation to possible susceptibility to air pollution.

UT-A2: a 55-kDa urea transporter in thin descending limb whose abundance is regulated by vasopressin

The renal urea transporter gene (UT-A) produces different transcripts in the inner medullary collecting ducts (UT-A1) and thin descending limbs of Henle's loop (UT-A2), coding for distinct proteins. Peptide-directed rabbit polyclonal antibodies were used to identify the UT-A2 protein in renal medulla of mouse and rat. In the inner stripe of outer medulla, an antibody directed to the COOH terminus of UT-A recognized a membrane protein of 55 kDa. The abundance of this 55-kDa protein was strongly increased in response to chronic infusion of the vasopressin analog 1-deamino-[8-D-arginine]vasopressin (DDAVP) in Brattleboro rats, consistent with previous evidence that UT-A2 mRNA abundance is markedly increased. Immunofluorescence labeling with the COOH-terminal antibody in Brattleboro rats revealed labeling in the lower portion of descending limbs from short-looped nephrons (in the aquaporin-1-negative portion of this segment). This UT-A labeling was increased in response to DDAVP. Increased labeling was also seen in descending limbs of long-looped nephrons in the base of the inner medulla. These results indicate that UT-A2 is expressed as a 55-kDa protein in portions of the thin descending limbs of Henle's loop and that the abundance of this protein is strongly upregulated by vasopressin.

Plasma fibrinogen, haemostatic factors and prediction of peripheral arterial disease in the Edinburgh Artery Study

The role of fibrinogen and other haemostatic factors in prediction of peripheral arterial disease (PAD) has not been established. We examined the associations of plasma fibrinogen, von Willebrand Factor (vWF), tissue plasminogen activator (t-PA) antigen, fibrin D-dimer, and factor VII with the development and clinical progression of PAD. In the Edinburgh Artery Study, 1592 men and women, aged between 55 and 74 years, were followed prospectively over 5 years to detect the onset of PAD, and the deterioration of established PAD. At baseline, 418 individuals had evidence of PAD and 60 (14.4%) subsequently deteriorated. 1080 subjects had no baseline disease, but 59 (5.5%) developed PAD during follow-up. Median levels of fibrinogen and vWF were higher in the group developing disease compared with the group which did not (2.78 g/l versus 2.57 g/l, P< or =0.01; 116 IU/dl versus 104 IU/dl, P< or =0.05; respectively). After adjusting for age and sex, fibrinogen (P< or =0.01) and vWF (P< or =0.05) were significantly associated with the risk of developing PAD. The association between fibrinogen and development of disease remained after adjusting for cardiovascular risk factors and baseline ischaemic heart disease (relative risk, 1.35, 95% confidence interval, 1.05, 1.73; P< or =0.05). None of the haemostatic factors were significantly associated with progression of PAD. In conclusion, plasma fibrinogen levels are related to the future onset of PAD, providing further evidence of a possible role of elevated fibrinogen in the development of atherosclerotic disease.

Essential fatty acids and cardiovascular disease: the Edinburgh Artery Study

The aim of this study was to determine whether plasma and red cell fatty acid levels were associated with cardiovascular disease, and whether any association was independent of other major risk factors. Over 1100 subjects were examined in a random sample survey of the general population (the Edinburgh Artery Study). Fatty acids were measured in three plasma fractions (triglyceride, cholesteryl ester and phospholipid) and in red cell phospholipids. Fatty acid levels in groups with cardiovascular disease (myocardial infarction (MI), angina and lower limb disease) were compared with a no disease group. In the cholesteryl ester and phospholipid fractions there were significantly lower levels of eicosapentaenoic acid in the MI group on univariate analysis (p<0.05), but not when adjusted for age, sex, smoking and systolic blood pressure using logistic regression. In the red cell fraction, alpha-linolenic acid was significantly lower in those with stroke (p<0.01) and lower limb disease (p<0.05). Linoleic acid was significantly raised in the triglyceride fraction in those with MI, probably reflecting recent dietary changes. There were significant increases in dihomo-gamma-linolenic acid in the phospholipid and red cell fractions in those with MI, and in the phospholipid fraction in the stroke group. These results do not support the hypothesis that n-6 fatty acids are protective against cardiovascular disease, although there may be some beneficial effects of the n-3 fatty acid, alpha-linolenic acid. Results from cross-sectional surveys must, however, be interpreted with caution because the presence of disease may affect dietary intake.

The effects of grapefruit juice on sertraline metabolism: an in vitro and in vivo study

Grapefruit juice is an inhibitor of cytochrome P-450 3A4 (CYP3A4). This study was designed to assess the in vitro and in vivo effects of grapefruit juice on sertraline metabolism. The in vitro assay involved analysis of sertraline metabolism by CYP3A4 using CYP3A4-expressed human beta-lymphoblast microsomes. The in vivo study involved high-performance liquid chromatographic analysis of serum trough levels of sertraline and desmethylsertraline in 5 patients who had been taking their usual dose of sertraline for > or =6 weeks, followed by concurrent use of sertraline with grapefruit juice for 1 week. The in vitro assay demonstrated that grapefruit juice inhibited the formation of desmethylsertraline in a dose-dependent manner. In the in vivo study, mean serum sertraline levels were determined in 5 patients with a history of depression (4 males and 1 female). The mean age of the patients was 68.6 years, their mean weight was 69.6 kg, and their mean sertraline dosage was 55 mg/d. The results of the in vivo study appeared to be consistent with the in vitro findings, in that mean (+/- SD) serum sertraline trough levels increased significantly from 13.7+/-4.9 microg/L before to 20.2+/-4.4 microg/L (P = 0.047) after administration of grapefruit juice. Thus the in vitro study demonstrated that grapefruit juice can inhibit the metabolism of sertraline. A larger study is warranted to substantiate the clinical significance of the in vivo findings.

Decreased renal Na-K-2Cl cotransporter abundance in mice with heterozygous disruption of the G(s)alpha gene

Transport processes along the nephron are regulated in part by hormone stimulation of adenylyl cyclases mediated by the heterotrimeric G protein G(s). To assess the role of this pathway in the regulation of Na-K-2Cl cotransporter abundance in the renal thick ascending limb (TAL), we studied mice with heterozygous disruption of the Gnas gene, which codes for the alpha-subunit of G(s). Outer medullary G(s)alpha protein abundance (as assessed by semiquantitative immunoblotting) and glucagon-stimulated cAMP production were significantly reduced in the heterozygous G(s)alpha knockout mice (GSKO) relative to their wild-type (WT) littermates. Furthermore, Na-K-2Cl cotransporter protein abundance in the outer medulla was significantly reduced (band density, 48% of WT). In addition, GSKO mice had a significantly reduced (72% of WT) urinary osmolality in response to a single injection of 1-deamino-[8-D-arginine]vasopressin (DDAVP), a vasopressin analog. In contrast, outer medullary protein expression of the type 3 Na/H exchanger (NHE-3) or Tamm-Horsfall protein did not differ between the GSKO mice and their WT littermates. However, abundance of type VI adenylyl cyclase was markedly decreased in the outer medullas of GSKO mice, suggesting a novel feed-forward regulatory mechanism. We conclude that expression of the Na-K-2Cl cotransporter of the TAL is dependent on G(s)alpha-mediated hormone stimulation, most likely due to long-term changes in cellular cAMP levels.

Cyclooxygenase inhibitors increase Na-K-2Cl cotransporter abundance in thick ascending limb of Henle's loop

Cyclooxygenase inhibitors, such as indomethacin and diclofenac, have well-described effects to enhance renal water reabsorption and urinary concentrating ability. Concentrating ability is regulated in part at the level of the thick ascending limb of Henle's loop, where active NaCl absorption drives the countercurrent multiplication mechanism. We used semiquantitative immunoblotting to test the effects of indomethacin and diclofenac, given over a 48-h period, on the expression levels of the ion transporters responsible for active NaCl transport in the thick ascending limb. Both agents strongly increased the expression level of the apical Na-K-2Cl cotransporter in both outer medulla and cortex. Neither agent significantly altered outer medullary expression levels of other thick ascending limb proteins, namely, the type 3 Na/H exchanger (NHE-3), Tamm-Horsfall protein, or alpha1- or beta1-subunits of the Na-K-ATPase. Administration of the EP3-selective PGE(2) analog, misoprostol, to indomethacin-treated rats reversed the stimulatory effect of indomethacin on Na-K-2Cl cotransporter expression. We conclude that cyclooxygenase inhibitors enhance urinary concentrating ability in part through effects to increase Na-K-2Cl cotransporter expression in the thick ascending limb of Henle's loop. This action is most likely due to elimination of an EP3-receptor-mediated tonic inhibitory effect of PGE(2) on cAMP production.

Serum amylase isoenzymes in patients undergoing operation for ruptured and non-ruptured abdominal aortic aneurysm

OBJECTIVE

Previous work has suggested that hyperamylasemia in patients who undergo operation for ruptured abdominal aortic aneurysm (AAA) is associated with poor outcome. The aims of this study were to determine, for the first time, the source of serum amylase in such patients and to examine the prognostic significance of amylase isoenzyme expression.

METHODS

This study was designed as a prospective clinical and laboratory study. The study consisted of 40 patients who underwent operation for ruptured AAA and 10 patients who underwent operation for non-ruptured AAA. The main outcome measures were serum total and pancreatic and salivary amylase activities determined with enzymatic colorimetric assay before operation and 6 hours after aortic clamp release.

RESULTS

Five of 40 patients (12.5%) with rupture and one of 10 patients (10%) with non-rupture had elevated total amylase levels before operation, and seven of 31 patients (23%) with rupture and five of 10 patients (50%) with non-rupture had elevated total amylase levels after operation. The preoperative salivary amylase (P =.05) and postoperative pancreatic amylase (P <.02) levels were significantly lower in ruptured AAA as compared with non-ruptured AAA. The preoperative salivary amylase level was significantly lower in non-survivors of rupture, such that a level equal to or less than 45 U/L was associated with death in 11 of 13 patients (85%).

CONCLUSION

These data do not support previous works that suggest that hyperamylasemia is associated with poor outcome in ruptured AAA. By contrast, a low preoperative salivary amylase level was associated with increased mortality in ruptured AAA and may be a marker of the severity of shock.

Controlled trial of oligofructose in the management of irritable bowel syndrome

A double-blind crossover trial of oligofructose (Raftilose P95) 2 g three times daily against sucrose (1 g) three times daily was performed in patients suffering from irritable bowel syndrome. Each treatment was followed for 4 wk. Patients consumed a standardized diet during the last 14 d of each treatment period, and symptoms were assessed using a previously validated questionnaire. Fecal weight and pH, whole-gut transit time and fasting breath hydrogen concentrations were measured at the start of the study and at the end of each treatment period. Oligofructose produced no significant change in any of these parameters even when patients were divided into those with predominant diarrhea (n = 14) and those with predominant constipation (n = 7). Oligofructose at a dose of 6 g/d had no therapeutic value in patients with irritable bowel syndrome.

The construction of a cDNA expression library for the sheep scab mite Psoroptes ovis

The need for alternative control strategies for sheep scab is critical. One approach is to develop vaccines based on 'concealed' antigens derived from Psoroptes ovis. This strategy requires the identification and characterisation of potential target antigens, which has been hampered by the problem of limited biological material for isolation of protein antigens. To aid the discovery of P. ovis antigens and to provide a resource for generating recombinant protein, we constructed a P. ovis cDNA expression library, using total RNA isolated from 250 mg of mixed-stage P. ovis and the Clontech SMART cDNA synthesis kit. The presence of P. ovis-specific sequences was confirmed using PCR amplification and sequencing of actin. The sequences of cDNA inserts from six random clones included one with high homology to the Dermatophagoides pteronyssinus (house dust mite) antigen p Dp15. This is a glutathione S-transferase known to be an important house dust mite antigen. We conclude that this library will be a useful tool for the identification of potential target antigens for the immunological control of P. ovis and to further our understanding of the pathology of sheep scab.

The role of haematological factors in diabetic peripheral arterial disease: the Edinburgh artery study

The relationship between haematological factors and peripheral arterial disease (PAD) among diabetics has not been widely examined. 1592 men and women aged 55-74 years were selected from the general population. They underwent an assessment for PAD and a glucose tolerance test. 288 subjects (18.7%) were identified as having diabetes or impaired glucose tolerance (IGT). Among the diabetes/IGT group, median levels of fibrinogen, von Willebrand factor (VWF), tissue plasminogen activator (t-PA), fibrin D-dimer and plasma viscosity were higher in subjects with PAD than those without PAD (P </= 0.05). The prevalence of PAD was higher in those with diabetes/IGT (20.6%) compared to those with normal glucose tolerance (12.5%) (odds ratio 1.64; 95% CI 1.17, 2.31). After separate adjustment for fibrinogen, VWF, t-PA, fibrin D-dimer, leucocyte elastase, plasma viscosity and haematocrit, those with diabetes/IGT no longer had a significantly higher risk of PAD compared to those with a normal glucose tolerance test. Simultaneous adjustment for the first four of these haematological factors reduced the risk of PAD among subjects with diabetes/IGT to 1.11 (95% CI 0.76, 1.63). Increased levels of haemostatic factors may partly explain the higher prevalence of PAD in diabetic/IGT subjects compared to normal glucose-tolerant subjects. Future randomized controlled trials involving the indirect lowering of levels of haematological factors should help to explain whether the associations reported here are of causal significance.

Interval-force relation is unaffected by the presence of cardiomyopathy or coronary artery disease in patients with atrial fibrillation

BACKGROUND

We tested the hypothesis that cycle length-dependent cardiac contractility in atrial fibrillation is primarily governed by the negative interval-force relation in patients with normal and depressed systolic function.

METHODS AND RESULTS

We performed two-dimensional guided M-mode echocardiography in 41 patients (mean age, 69 +/- 4 years; range, 48 to 92 years; 19 men, 11 women). Twelve patients had objective evidence of left ventricular systolic dysfunction (CMP; mean ejection fraction, 37% +/- 7%) in the absence of coronary artery disease (CAD), 13 patients had documented CAD (mean ejection fraction, 43% +/- 6%), and 16 patients had normal resting left ventricular systolic function (mean ejection fraction, 58% +/- 7%). Simultaneous beat-to-beat blood pressure, end-systolic and end-diastolic dimension, circumferential velocity of fiber shortening (Vcf), and end-systolic wall stress (ESWS) were calculated for all patients. All three groups showed a significant linear relation between beat-to-beat Vcf and Vcf corrected for afterload (represented as the Vcf/ESWS ratio) and preceding cycle length. There was, however, no significant difference in the relation between either of these variables and cycle length among the three groups. There was also no difference in the rate of change in either Vcf or Vcf corrected for afterload (Vcf/ESWS ratio) from beat-to-beat among the three groups. Control patients with normal systolic function showed greater Vcf at any given cycle length compared with patients with CMP or CAD.

CONCLUSION

Our data show that, for each beat in atrial fibrillation, Vcf and Vcf/ESWS ratio are decreased after shorter cycle lengths and increased after long cycles, but there is no significant attenuation of this effect in patients with systolic dysfunction with or without coronary disease compared with controls. Thus, the negative interval-force relation, the predominant determinant of beat-to-beat variation in contractility in atrial fibrillation, is preserved in patients with CAD or reduced left ventricular systolic function.

Vascular surgical society of great britain and ireland: symptoms of varicose veins

BACKGROUND: The relationships between varicose veins (VVs) and leg symptoms have not been studied. The aim of this study was to define the relationships between age, sex, leg symptoms and VVs. METHODS: An age-stratified sample of 699 men and 867 women aged 18-64 years, selected randomly from 12 general practices distributed socioeconomically throughout the city, completed a questionnaire regarding leg symptoms (heaviness/tension, swelling, aching, restless legs, cramps, itching, tingling) and underwent a clinical examination. RESULTS: In men, swelling and cramps (both P </= 0.001), and in women swelling (P = 0.02), restless legs (P = 0.001) and itching (P = 0.045), were significantly more common in older subjects. Data have therefore been age adjusted. Women were significantly (P < 0.01) more likely to respond positively when asked about all leg symptoms, except tingling. The commonest symptoms were aching in women (53.8 per cent) and cramps in men (34. 0 per cent). There was no difference between right and left legs. In men, only itching was significantly related to trunk VVs (P = 0.011). In women, there was a relationship between trunk VVs and heaviness/tension, aching and itching (P </= 0.005). Hyphen-web varices were not related to symptoms in men but were related to heaviness/tension and swelling in women. There was no association between reticular varices and symptoms in either sex. CONCLUSION: Even in the presence of VVs, most lower limb 'venous' symptoms are non-venous in aetiology. Surgery is unlikely to ameliorate symptoms in the majority of patients.

Fibrinogen, factor VII and PAI-1 genotypes and the risk of coronary and peripheral atherosclerosis: Edinburgh Artery Study

There are now many epidemiological studies that have shown a relationship between haemostatic factors and subsequent risk of both coronary and peripheral arterial disease. However, there is less information on the association between genetic variation in these factors and the risks of coronary and peripheral arterial disease. As part of the five-year follow-up of the Edinburgh Artery Study, polymorphisms of the fibrinogen (-455G/A), factor VII (R/Q353) and PAI-1 (HindIII) genes were measured in men and women aged 60-79 years, together with their plasma levels. Using widely accepted criteria, 88 subjects were identified as having peripheral arterial disease (PAD), 195 having coronary artery disease (CAD) and 423 subjects comprised a "healthy" group. The -455AA genotype of the fibrinogen gene was found to be more frequent among those subjects with PAD. This genotype also showed the highest plasma fibrinogen levels in both disease groups and in the healthy group. Using logistic regression, after adjustment for age, sex, smoking and plasma level, the -455AA genotype was associated with over twice the risk of PAD compared with the -455GG genotype, the odds ratio reaching marginal significance (p < or = 0.10). Combining those with genotype -455AA with the heterozygotes in order to increase the power of the study resulted in a more significant multiple-adjusted risk of PAD (p < or = 0.05). These data provide evidence that a polymorphism of the P fibrinogen gene is associated with an increased risk of peripheral atherosclerosis.

Gingival crevicular fluid osteocalcin in adult periodontitis

This study aimed to detect the levels of osteocalcin in gingival crevicular fluid (GCF) from healthy (< or =3 mm sulcus depth and non-bleeding) and diseased sites (> or =6 mm probing depth and bleeding) in subjects with adult periodontitis, in order to further investigate its potential as a possible marker of the disease process. Periodontal probing depths, attachment levels and gingival indices were recorded from one healthy and one diseased site in each of 20 subjects with adult periodontitis. Both GCF accumulated in the periodontal pocket or sulci and GCF flowing into the periodontal pocket or sulci over a three-minute interval were sampled. The amounts of osteocalcin in each GCF sample was determined using immunoassays. A mean of 2.34 ng/site (2.7 microg/ml) osteocalcin was found at diseased sites and a mean of 2.47 ng/site (5.47 microg/ml) was found at healthy sites for the accumulated GCF collection method. A mean of 0.17 ng/ site (2.17 microg/ml) osteocalcin was found at diseased sites and a mean of 0.14 ng/ site (1.85 microg/ml) at healthy sites for the flow method of GCF collection. There were no statistically significant differences between osteocalcin levels in diseased and healthy sites in subjects with adult periodontitis.

Role of systolic blood pressure and plasma triglycerides in diabetic peripheral arterial disease. The Edinburgh Artery Study

OBJECTIVE

To determine the risk factors for peripheral arterial disease (PAD) in a diabetic population and to examine whether different levels of these risk factors might explain why diabetic subjects have an increased risk of PAD compared with normal glucose tolerance subjects.

RESEARCH DESIGN AND METHODS

There were 1,592 men and women aged 55-74 years selected at random from the age-sex registers of 11 general practices in Edinburgh, Scotland. Subjects underwent a comprehensive medical examination, including assessment for PAD (intermittent claudication on World Health Organization questionnaire or major asymptomatic disease on noninvasive testing) and a glucose tolerance test.

RESULTS

Of the subjects, 288 (18.7%) were found to have diabetes or impaired glucose tolerance (IGT). The prevalence of PAD was greater in those with diabetes/IGT (20.6%) compared with those with normal glucose tolerance (12.5%) (odds ratio [OR] 1.64, 95% CI 1.17-2.31). Among the diabetes/IGT group, mean levels of smoking, systolic blood pressure, and triglycerides were higher in subjects with PAD than in those without PAD (P < or = 0.05). Mean levels of systolic blood pressure and plasma triglycerides were also higher in diabetic subjects than in nondiabetic subjects with PAD (P < or = 0.05). In multivariate analysis, those with diabetes/IGT no longer had a significantly higher risk of PAD after adjusting separately for systolic blood pressure (OR 1.22, 95% CI 0.85-1.73) and plasma triglycerides (OR 1.26, 95% CI 0.89-1.79). Simultaneous adjustment for both systolic blood pressure and triglycerides reduced the risk of PAD among diabetic subjects to 1.11 (95% CI 0.78-1.58).

CONCLUSIONS

Increased mean levels of triglycerides and systolic blood pressure may help to explain the higher prevalence of PAD in diabetic subjects compared with that in normal glucose tolerance subjects.

The relationship between abdominal aortic aneurysm wall compliance, maximum diameter and growth rate

AIM

Aortic compliance as measured by the pressure-strain elastic modulus (Ep) and stiffness (beta), may allow a more precise estimate of rupture risk. The aim of this study was to determine the relationships between compliance, maximal aneurysm diameter and growth rate.

METHODS

Sixty abdominal aortic aneurysm patients of median age 73 years, were studied. Growth rate was derived from repeat ultrasound scans obtained over a median period of 21 months (range 6-48). At the end of follow-up, patients underwent measurement of maximum aortic diameter, Ep and beta using the Diamove echo-tracking system.

RESULTS

Growth rate correlated positively (r = 0.6, P < 0.01) with maximum diameter on entry to the study There was a positive correlation between mean arterial pressure and Ep (r = 0.3, P = 0.03), but not between mean arterial pressure and beta (r = 0.8, P = 0.61). A positive correlation was found between final maximum diameter and Ep (r = 0.22, P = 0.04) but not beta (r = 0.16, P = 0.11). There was no significant relationship between growth rate and Ep or beta.

CONCLUSION

Large aneurysms tended to be less compliant. Within a population of abdominal aortic aneurysm of similar maximum diameter there was a 10-fold variation in Ep and beta. Compliance and growth rate were not related. If aortic compliance is related to risk of rupture then this predictive information is likely to be largely independent of that currently obtained from size and growth rate.

Relationship between smoking and cardiovascular risk factors in the development of peripheral arterial disease and coronary artery disease: Edinburgh Artery Study

AIMS

The aim was to determine whether the effect of smoking on the development of peripheral or coronary artery disease might be mediated by other cardiovascular risk factors, including dietary antioxidant vitamin intake, serum low and high density lipoproteins, blood pressure, plasma fibrinogen, blood viscosity and markers of endothelial disturbance and fibrin turnover.

METHODS AND RESULTS

1592 men and women aged 55-74 years were selected at random from 11 general practices in Edinburgh, Scotland and followed-up for 5 years. The incidences of peripheral arterial disease and coronary artery disease were 5.1% and 11.1%, respectively. Both conditions were more common in moderate and heavy smokers than in never smokers: cigarette smoking was a stronger risk factor for peripheral arterial disease than for coronary artery disease. Smoking was associated with reduced dietary antioxidant vitamin intake, serum high density lipoprotein cholesterol and diastolic blood pressure and with increased alcohol intake, serum triglycerides, blood viscosity, plasma fibrinogen, and markers of endothelial disturbance (tissue plasminogen activator and von Willebrand factor antigens). Simultaneous adjustment for these risk factors reduced the relative risk of peripheral arterial disease only slightly, from 3.94 (95% CI 2.04, 7.62) to 2.72 (95% CI 1.13, 6.53) in heavy smokers and from 1.87 (95% CI 0.91, 3.85) to 1.70 (95% CI 0.72, 3.99) in moderate smokers. Similar adjustment also had little effect on the risk of coronary artery disease associated with smoking.

CONCLUSION

The combined effect of smoking on the cardiovascular risk factors studied may explain part of its influence on peripheral and coronary arterial disease, but the majority of the effect appears to be due to other mechanisms.

Prevalence of varicose veins and chronic venous insufficiency in men and women in the general population: Edinburgh Vein Study

STUDY OBJECTIVE

To determine the prevalence of varicose veins and chronic venous insufficiency (CVI) in the general population.

DESIGN

Cross sectional survey.

SETTING

City of Edinburgh.

PARTICIPANTS

Men and women aged 18-64 years selected randomly from age-sex registers of 12 general practices.

MAIN RESULTS

In 1566 subjects examined, the age adjusted prevalence of trunk varices was 40% in men and 32% in women (p < or = 0.01). This sex difference was mostly a result of higher prevalence of mild trunk varices in men. More than 80% of all subjects had mild hyphenweb and reticular varices. The age adjusted prevalence of CVI was 9% in men and 7% in women (p < or = 0.05). The prevalence of all categories of varices and of CVI increased with age (p < or = 0.001). No relation was found with social class.

CONCLUSIONS

Approximately one third of men and women aged 18-64 years had trunk varices. In contrast with the findings in most previous studies, mainly conducted in the 1960s and 1970s, chronic venous insufficiency and mild varicose veins were more common in men than women. No evidence of bias in the study was found to account for this sex difference. Changes in lifestyle or other factors might be contributing to an alteration in the epidemiology of venous disease.

Factors influencing tackle injuries in rugby union football

OBJECTIVES

To assess the influence of selected aspects of lifestyle, personality, and other player related factors on injuries in the tackle. To describe the detailed circumstances in which these tackles occurred.

METHODS

A prospective case-control study was undertaken in which the tackling and tackled players ("the cases") involved in a tackle injury were each matched with "control" players who held the same respective playing positions in the opposing teams. A total of 964 rugby matches involving 71 senior clubs drawn from all districts of the Scottish Rugby Union (SRU) were observed by nominated linkmen who administered self report questionnaires to the players identified as cases and controls. Information on lifestyle habits, match preparation, training, and coaching experience was obtained. A validated battery of psychological tests assessed players' trait anger and responses to anger and hostility. The circumstances of the tackles in which injury occurred were recorded by experienced SRU coaching staff in interviews with involved players after the match.

RESULTS

A total of 71 tackle injury episodes with correct matching of cases and controls were studied. The following player related factors did not contribute significantly to tackle injuries: alcohol consumption before the match, feeling "below par" through minor illness, the extent of match preparation, previous coaching, or practising tackling. Injured and non-injured players in the tackle did not differ in their disposition toward, or expression of, anger or hostility. Some 85% of tackling players who were injured were three quarters, and 52% of injuries occurred when the tackle came in behind the tackled player or within his peripheral vision. Either the tackling or tackled player was sprinting or running in all of these injury episodes. One third of injuries occurred in differential speed tackles--that is, when one player was travelling much faster than the other at impact. The player with the lower momentum was injured in 80% of these cases. Forceful or crunching tackles resulting in injury mostly occurred head on or within the tackled player's side vision.

CONCLUSIONS

Attention should be focused on high speed tackles going in behind the tackled player's line of vision. Comparative information on the circumstances of the vast majority of tackles in which no injury occurs is required before any changes are considered to reduce injuries in the tackle.

Pill-induced esophagitis caused by oral rifampin

OBJECTIVE

To report a case of pill-induced esophagitis caused by oral rifampin.

DATA SOURCES

English-language references identified via a MEDLINE search from January 1966 to May 1998 and a bibliographic review of pertinent articles.

DATA SYNTHESIS

A large number of oral medications have been reported to cause pill-induced esophagitis. This case represents the second report attributed to rifampin. A 70-year-old white man receiving vancomycin, gentamicin, and oral rifampin for treatment of Staphylococcus epidermidis prosthetic valve endocarditis reported dysphagia immediately after swallowing a rifampin capsule on the fourth day of therapy. The following day, fiberoptic laryngoscopy and esophagoscopy demonstrated a red capsule partially embedded in the neopharynx. A day later, upper esophageal obstruction consistent with edema related to pill-induced esophagitis was identified by barium swallow. Following the procedure, the patient was placed on total parenteral nutrition and took nothing by mouth. Sixteen days after first reporting dysphagia, he was placed on a full liquid diet. Several factors may have increased the patient's risk for pill-induced esophagitis, including age, bedridden state, gastroesophageal reflux disease, simultaneous administration of several medications, and neopharyngeal stricture.

CONCLUSIONS

Oral rifampin may cause esophagitis. Healthcare providers should be alert to the possibility of pill-induced esophagitis in susceptible patients. Patients with predisposing factors for the development of pill-induced esophagitis should be educated about proper swallowing of oral medications.

Randomized controlled trial of gamma-linolenic acid and eicosapentaenoic acid in peripheral arterial disease

BACKGROUND AND AIMS

epidemiological studies suggest polyunsaturated fatty acids protect against the development of atherosclerosis. The aim of this study was to perform a randomized controlled trial of gamma-linolenic and eicosapentaenoic acids in patients with lower limb atherosclerosis. Main outcome measures were: cholesterol and lipoprotein concentrations; haemostatic and rheological variables; the ankle brachial pressure index; walking distance; and cardiovascular events and death.

METHODS

120 men and women with stable intermittent claudication were randomized to 2 years treatment with either a combination of gamma-linolenic and eicosapentaenoic acids, or placebo.

RESULTS

39 (65.0 cent) of those taking fatty acids and 36 (60.0 cent) of those taking placebo completed the trial. Lipid concentrations did not differ significantly during the trial. In those taking fatty acids, haematocrit was significantly higher than in the placebo group after 6 months (46.1 cent compared with 44.6 cent, P </= 0.01), and systolic blood pressure was significantly lower after 2 years (150|mmHg compared with 161.8|mmHg, </= 0.05). There was no difference in walking distance, but there was a small reduction in non-fatal coronary events in the fatty acid group (10 cent compared with 15 cent, P > 0.05).

CONCLUSIONS

a combination of polyunsaturated fatty acids produced a statistically significant reduction in systolic blood pressure, but no other significant benefits on risk factors. The trend towards fewer coronary events in those taking fatty acids warrants further investigation.

Prevalence of venous reflux in the general population on duplex scanning: the Edinburgh vein study

PURPOSE

The prevalence of reflux in the deep and superficial venous systems in the Edinburgh population and the relationship between patterns of reflux and the presence of venous disease on clinical examination were studied.

METHODS

A cross-sectional survey was done on men and women ranging in age from 18 to 64 years, randomly selected from 12 general practices. The presence of varicose veins and chronic venous insufficiency was noted on clinical examination, as was the duration of venous reflux by means of duplex scanning in 8 vein segments on each leg. Results were compared using cut-off points for reflux duration (RD) of 0.5 seconds or more (RD >/= 0.5) and more than 1.0 second (RD > 1.0) to define reflux.

RESULTS

There were 1566 study participants, 867 women and 699 men. The prevalence of reflux was similar in the right and left legs. The proportion of participants with reflux was highest in the lower thigh long saphenous vein (LSV) segment (18.6% in the right leg and 17.5% in the left leg for RD >/= 0.5), followed by the above knee popliteal segments (12.3% in the right leg and 11.0% in the left leg for RD >/= 0.5), the below knee popliteal (11.3% in the right leg and 9.5% in the left leg for RD >/= 0.5), upper LSV (10.0% in the right leg and 10.8% in the left leg for RD >/= 0.5) segments, the common femoral vein segments (7.8% in the right leg and 8.0% in the left leg for RD >/= 0.5), the lower superficial femoral vein (SFV) segments (6.6% in the right leg and 6.4% in the left leg for RD >/= 0.5), and the upper SFV (5.2% in the right leg and 4.7% in the left leg for RD >/= 0.5) and short saphenous vein (SSV) (4.6% in the right leg and 5.6% in the left leg for an RD >/= 0.5) segments. In the superficial vein segments, there was little difference in the occurrence of reflux whether RD >/= 0.5 or RD > 1.0 was used; but in the different deep vein segments, the prevalence of reflux was 2 to 4 times greater for RD >/= 0.5 rather than RD > 1.0. Men had a higher prevalence of reflux in the deep vein segments than women, reaching statistical significance (P </=.01) in 4 of 5 segments for RD >/= 0.5. In general, the prevalence of reflux increased with age. Those with "venous disease" had a significantly higher prevalence of reflux in all vein segments than those with "no disease" (P </=.001).

CONCLUSION

The prevalence of venous reflux in the general population was related to the presence of "venous disease," although it was also present in those without clinically apparent disease. There was a higher prevalence of reflux in the deep veins in men than the deep veins in women. Follow-up study of the population will determine the extent to which reflux is a predictor of future disease and complications.

Porosity reduction in acrylic cement is clinically irrelevant

Evidence from studies on migration raises serious doubts regarding the part played by fatigue failure of acrylic bone cement in the genesis of aseptic loosening of the components of total hip arthroplasties. Moreover, the viscoelastic properties of cement raise serious doubts concerning the relevance of conventional laboratory fatigue studies to the in vivo behavior of acrylic cement. It is not surprising that there is considerable clinical evidence that reduction of porosity in acrylic cement is of no relevance to the long term outcomes of total hip arthroplasty. These matters remain controversial, and randomized prospective trials would be necessary to settle the issues. For various reasons, such trials are unlikely to be performed.

The natural history of untreated lower urinary tract symptoms in middle-aged and elderly men over a period of five years

OBJECTIVES

To describe changes in untreated lower urinary tract symptoms (LUTS), levels of bothersomeness and interference in selected living activities arising from LUTS in a cohort of men followed up for a period of 5 years.

METHODS

1,994 men aged 40-79 years registered in four health centres in Scotland completed a urinary symptom questionnaire in the community. 1,177 (71% of original eligible participants) were followed up at 5 years.

RESULTS

The mean level of LUTS and the level of bothersomeness they caused increased universally between baseline and 5 years. The largest increases in mean symptom levels occurred for straining, hesitancy, incomplete emptying, weak stream and nocturia, and for mean levels of bothersomeness, i.e. dribbling, incomplete emptying, weak stream, frequency, nocturia and intermittency. The increase in mean interference level in selected living activities arising from LUTS was less marked. The progression of LUTS over time in individual men was very variable; however, the overall trend was one of continuing deterioration.

CONCLUSION

If left untreated, overall levels of middle-aged and elderly mens' LUTS, bothersomeness and interference in selected activities caused by these symptoms will increase over time.

Pathophysiological relationships between lower urinary tract symptoms and the prostate do not strengthen over time

BACKGROUND

The aim of this survey was to examine the relationships among baseline prostate gland volume and changes in urinary symptomatology 3 years later.

METHODS

A Scottish community-based cohort of 193 men aged 40-79 years who had prostate volume measured by transrectal ultrasound (TRUS) were followed-up at 3 years.

RESULTS

Only baseline nocturia correlated with prostate volume (r = 0.202, P = 0.0057), although some relationships existed for the antero-posterior dimension of the prostate gland. More statistically significant relationships were evident for adenoma volume rather than prostate volume, but they still had relatively low correlations (range, 0.19-0.31).

CONCLUSIONS

This study demonstrates the lack of relationships between prostate gland variables and lower urinary tract symptoms (LUTS). Those relationships that are statistically significant (at the P < 0.01 level) are weak, and only explain at most 9% of the total variation of prostate or adenoma volume or their dimensions.

Cardiac performance early after cardioversion from atrial fibrillation

BACKGROUND

The mechanism for early improvement in cardiac function after cardioversion from atrial fibrillation is unknown.

METHODS

We measured ventricular volumes and load-independent contractility during atrial fibrillation and within 24 hours after cardioversion to sinus rhythm in 15 adult patients (10 men, 5 women; mean age 63+/-4 years, range 31 to 81 years). Duration of atrial fibrillation ranged from <1 day to 6 months.

RESULTS

After cardioversion, left ventricular ejection fraction increased from 51%+/-4% to 61%+/-4% (P=.001, 95% confidence intervals for the difference, 7% to 15%), stroke volume increased from 57+/-4 mL to 76+/-6 mL (P < .001, 95% confidence intervals 8 to 32 mL), and mean cycle length increased from 0.77+/-.04 seconds in atrial fibrillation to 1.02+/-.04 seconds in sinus rhythm (P=.002, 95% confidence intervals, 0.1 to 0.4 seconds). Cardiac contractility, as expressed by the slope and the intercept of the relation between rate-corrected circumferential velocity of fiber shortening and end-systolic wall stress (Vcfc/ESWS) remained unaltered in 13 of 15 patients, suggesting that intrinsic inotropic state was unchanged immediately after return of normal sinus rhythm. Finally, a significant correlation was observed between improvement in stroke volume and peak A-wave velocity (r=0.79, P=.035).

CONCLUSION

Both left ventricular stroke volume and ejection fraction increase immediately after cardioversion, whereas intrinsic cardiac contractility is largely unchanged. These data suggest that the mechanism of this increase is enhanced left ventricular diastolic filling due mostly to increased cycle length and return of left atrial mechanical function.

Do black elderly Medicare patients receive fewer services? An analysis of procedure use for selected patient conditions

Blacks have been shown to undergo fewer medical procedures than Whites, particularly for coronary disease. This article uses logistic regression to analyze racial disparities in procedure use among older Medicare enrollees admitted for coronary artery disease, stroke, hip fracture, and colon and breast cancer. Medicare enrollment and claims data are used to identify hospitalizations and procedure use, and to measure other individual-level information. No racial differences in procedure use are found for hip fracture and colon/breast cancer patients, life-threatening diseases for which basic approaches to evaluation and treatment are widely accepted. Substantial differences, however, are found for coronary disease and stroke, two illnesses whose treatment involves substantially greater discretion.

Staff development in pharmacist-conducted patient education and counseling

A staff development program designed to improve pharmacists' counseling skills and to allow participants to achieve a minimum level of competence in counseling is described. The pharmacy service at a Department of Veterans Affairs medical center selected a workshop emphasizing the principles of the Indian Health Service (IHS) interactive counseling technique as the basis for a training program for staff pharmacists. The program was expanded to meet the pharmacy's counseling training needs. Handouts on 70 of the most frequently prescribed outpatient medications; administration techniques for oral and nasal inhalers and ophthalmic agents; and 32 common diseases were included in training manuals. Seven standard cases were developed for role-playing sessions, the purpose of which was to increase pharmacists' level of confidence in using the IHS technique and in counseling patients about common diseases and medications. Each pharmacist's counseling technique was assessed by a facilitator. Knowledge of commonly prescribed medications was assessed by an open-book written examination. The pharmacists' self-reported level of confidence in counseling patients about common diseases and medications was significantly improved after the training program. A counseling training program enabled pharmacists to achieve a minimum level of competence in counseling and increased their confidence in their counseling skills.

The solution structure of an RNA loop-loop complex: the ColE1 inverted loop sequence

BACKGROUND

Replication of the ColE1 plasmid of Escherichia coli is regulated by the interaction of sense and antisense plasmid-encoded transcripts. The antisense RNA I negatively regulates the replication of the plasmid by duplex formation with complementary RNA II. The interaction is initiated by the formation of a double helix between seven-nucleotide loops from each RNA and is stabilized by binding of the RNA one modulator (ROM) protein. The ROM protein is thought to recognize a specific RNA structure, regardless of sequence.

RESULTS

The solution structure of a loop-loop complex between model RNA hairpins that resemble RNA I and RNA II has been determined by nuclear magnetic resonance spectroscopy. The model hairpins have loop sequences inverted 5' to 3' relative to the wild-type sequence and were chosen because of their complex's slow dissociation in comparison to the wild type. The complex has continuous stacking from the 3'-side of one stem helix through the loop-loop helix to the other stem helix. One residue from each hairpin has a unique phosphodiester bond which bridges and narrows the major groove. These bridging phosphates are in close proximity to the phosphate groups of the adjacent bases, forming unique structural motifs called phosphate clusters. The purine residue at the 3'-end of the loop-loop helix of one RNA stacks on a purine residue on the 5'-side of the other RNA stem, and there are strong cross-strand stacking interactions between guanine bases in the stem helices adjacent to the loops.

CONCLUSIONS

Unique distortions, such as the strong bend and the phosphate clusters flanking the major groove of the loop-loop helix, provide an attractive nonsequence-specific structural feature for recognition by the ROM protein. The structure provides a basis for rationalizing the sequence dependence of the stability of loop-loop interaction.

Vesicle-associated brain myosin-V can be activated to catalyze actin-based transport

Myosin-V has been linked to actin-based organelle transport by a variety of genetic, biochemical and localization studies. However, it has yet to be determined whether myosin-V functions as an organelle motor. To further investigate this possibility, we conducted a biochemical and functional analysis of organelle-associated brain myosin-V. Using the initial fractionation steps of an established protocol for the purification of brain myosin-V, we isolated a population of brain microsomes that is approx. fivefold enriched for myosin-V, and is similarly enriched for synaptic vesicle proteins. As demonstrated by immunoelectron microscopy, myosin-V associates with 30–40% of the vesicles in this population. Although a majority of myosin-V-associated vesicles also label with the synaptic vesicle marker protein, SV2, less than half of the total SV2-positive vesicles label with myosin-V. The average size of myosin-V/SV2 double-labeled vesicles (90+/−45 nm) is larger than vesicles that label only with SV2 antibodies (60+/−30 nm). To determine if these vesicles are capable of actin-based transport, we used an in vitro actin filament motility assay in which vesicles were adsorbed to motility assay substrates. As isolated, the myosin-V-associated vesicle fraction was nonmotile. However, vesicles pre-treated with ice-cold 0.1% Triton X-100 supported actin filament motility at rates comparable to those on purified myosin-V. This dilute detergent treatment did not disrupt vesicle integrity. Furthermore, while this treatment removed over 80% of the total vesicle proteins, myosin-V remained tightly vesicle-associated. Finally, function-blocking antibodies against the myosin-V motor domain completely inhibited motility on these substrates. These studies provide direct evidence that vesicle-associated myosin-V is capable of actin transport, and suggest that the activity of myosin-V may be regulated by proteins or lipids on the vesicle surface.

A 3-month, double-blind, controlled trial of feeding with sucrose polyester in human volunteers

Sucrose polyester (SPE) is a tasteless, odourless substance which reduces plasma cholesterol concentrations and may therefore be valuable as a fat substitute in human foodstuffs. It has recently been approved for use in snack foods by the United States Federal Drug Administration. The current study was designed to investigate its effects on gastrointestinal physiology and nutrient absorption in human subjects. A 6-month (2 x 3-month periods) double-blind, placebo-controlled, randomized, cross-over trial of SPE and control fat was performed in healthy free-living volunteers. Subjects consumed 20-40 g of SPE daily (mean 26.8 (SE 6.8) g) which reduced the intake of total and saturated fat but had no effect on energy intake or body weight. Plasma cholesterol and triacylglycerols were reduced. The frequency of bowel movements and their urgency were increased and anal leakage occurred in 7.2% of subjects. Abdominal pain was more frequent in subjects receiving SPE and was significantly greater than in the control group after 8 weeks feeding. The plasma concentrations of vitamin E and six carotenoids were significantly reduced. Routine haematology and biochemistry, other vitamins, intestinal biopsies, bile-salt retention, rectal prostaglandins, fractional Ca absorption and aminopyrine metabolism were unaffected. The ingestion of foods containing 20-40 g SPE daily provoked significant gastrointestinal problems. This intake is greater than that to be expected from the use of SPE in savoury snack foods, for which it has been approved by the United States Federal Drug Administration. However, the favourable effects on lipid profiles must be balanced against the reduction in the concentrations of vitamins and carotenoids, as these compounds may have beneficial effects on health through protection from free-radical oxidative stress.

Smoking, hemorheologic factors, and progression of peripheral arterial disease in patients with claudication

PURPOSE

The purpose of the current study was to determine whether hemostatic and rheologic factors are associated with the deterioration of peripheral arterial disease in patients with intermittent claudication and the influence of smoking and severity of underlying disease on these relationships.

METHODS

We conducted a prospective cohort study with a 6-year follow-up period of a consecutive series of 607 patients with uncomplicated intermittent claudication. The study setting was the Peripheral Vascular Clinic, Royal Infirmary of Edinburgh. The main outcome measures were peripheral vascular intervention or onset of severe chronic leg ischemia (rest pain, ulceration, gangrene).

RESULTS

A total of 210 patients died during follow-up. Two hundred three patients did not have a vascular event or deterioration of limb ischemia, 45 patients underwent a peripheral vascular intervention, and 64 progressed to severe chronic leg ischemia. Median levels (interquartile ranges) of whole blood viscosity were significantly higher in the vascular intervention group (3.75 mPa/sec; range, 3.38 to 4.13 mPa/sec) than in those who did not deteriorate 3.48 mPa/sec; range, 3.06 to 3.83 mPa/sec) (p < or = 0.05), and plasma von Willebrand factor was higher in those with severe chronic leg ischemia (154.0 IU/dl; range, 122.0 to 187.0 IU/dl) than in those who did not deteriorate (131.0 IU/dl; range, 106.0 to 165.0 IU/dl) (p < or = 0.01). After adjustment for age, sex, cigarette smoking, and ankle brachial pressure index, the levels of plasma fibrinogen and blood and plasma viscosities were each associated with an increased risk of vascular intervention (all p < or = 0.05). There were no significant associations between any of the hemorheologic factors and the risk of severe chronic leg ischemia on multivariate analyses.

CONCLUSION

Elevations in rheologic factors may have important effects on further reduction of blood flow in the legs of patients with claudication and promote worsening ischemia and clinical progression of symptoms.

Escape from vasopressin-induced antidiuresis: role of vasopressin resistance of the collecting duct

Previously, we demonstrated that escape from vasopressin-induced antidiuresis ("vasopressin escape") in rats is associated with a large, selective decrease in whole kidney expression of aquaporin-2, the vasopressin-regulated water channel. Here, we show that isolated perfused inner medullary collecting ducts (IMCDs) from vasopressin-escape rats desamino-[D-arginine]vasopressin (DDAVP)/water-loaded have dramatically reduced vasopressin-dependent osmotic water permeabilities [46% of control rats (DDAVP alone)], which coincides with a fall in inner medullary aquaporin-2 protein abundance as measured by immunoblotting in the opposite kidney. Furthermore, we demonstrate in IMCD suspensions that cAMP accumulation in response to DDAVP is substantially reduced in the vasopressin-escape rats both in the presence and absence of the phosphodiesterase inhibitor IBMX. By immunoblotting, we show that the abundance of two proteins important in cAMP generation: the stimulatory heterotrimeric G protein subunit Gs and adenylyl cyclase type VI, do not change. We conclude that vasopressin escape is associated with relative vasopressin resistance of the collecting duct cells manifested by decreased intracellular cAMP levels. The decreased cAMP levels can contribute to the demonstrated decrease in collecting duct water permeability in two ways: 1) by causing a decrease in aquaporin-2 expression and 2) by limiting the acute action of vasopressin to increase collecting duct water permeability.

Mathematical modelling of the release of drug from porous, nonswelling transdermal drug-delivery devices

A general model is presented for the release of drug from porous nonswelling, transdermal drug-delivery devices and it is shown to reduce to previously proposed models in suitable limits. The processes which govern the release of drug are considered to be diffusion of dissolved drug and dissolution of dispersed drug, both in the body of the device and in the device pores, and transfer of drug between the two domains. In the classical limit of large dissolution rates, the problem reduces to one of the moving-boundary type, and solution of this problem in the case where the initial drug loading is much greater than the drug solubility in the device yields expressions for the flux of drug to a perfect sink (modelling in vitro conditions). It is shown that behaviour greatly differing from the classical first-order drug delivery (alpha t 1/2) may be exhibited, depending upon the parameter regime. In some situations the dissolution rates may not be so large and solutions of the general model are derived in the case where the dispersed drug is considered to be undepleted and the diffusivity in the solvent-filled pores is much larger than in the body of the delivery device. Numerical studies are undertaken, and the coupling of delivery device and skin-diffusion models (in order to model the complete transdermal drug-delivery process) is also considered.

The dispersions of estimates of sensitivity obtained from four psychophysical procedures: implications for experimental design

The dispersions of estimates of sensitivity obtained from the yes-no, two-alternative forced-choice (2AFC), matching-to-sample, and same-different tasks were examined to determine which task would be more appropriate to use in a given experimental context. Consideration was given to the effects of corrections for extreme sampled proportions. These corrections result in biased estimators, and hence the mean-square deviation of the sampled values about the population mean [MSD(d')], rather than that about the mean of the estimates [VAR(d')], indicates more completely the extent of the error in the estimator. For barely discriminable events (d' approximately equal to 0.5), the yes-no and 2AFC tasks had the lowest values of MSD(d'). However, for very discriminable events(d > 3), the same-different and matching-to-sample tasks had lower values of MSD(d').

Blood viscosity and elevated carotid intima-media thickness in men and women: the Edinburgh Artery Study

BACKGROUND

Several hemostatic and rheological factors have been associated with incident cardiovascular events. However, there have been no reports on the relationship of rheological factors with early atherosclerosis and very few on hemostatic factors. We therefore studied the relationship between these factors and carotid intima-media thickness (IMT).

METHODS AND RESULTS

The Edinburgh Artery Study measured fibrinogen, tissue plasminogen activator (tPA), fibrin D-dimer, von Willebrand factor (vWF), blood and plasma viscosities, and hematocrit as part of its baseline examination during 1988-1989. At the 5-year follow-up, valid measurements of IMT had been recorded in 1106 men and women 60 to 80 years old. In men, blood viscosity (P< or =.001) and its major determinants, plasma viscosity, fibrinogen (both P< or =.01), and hematocrit (P< or =.05), were all linearly related to IMT. Furthermore, blood viscosity, fibrinogen (both P< or =.01), and plasma viscosity (P< or =.05) remained significantly associated on multivariate analysis. Correcting blood viscosity to a standard hematocrit of 45% had little effect on its association. In men, there was a significantly increased risk of having an IMT above versus below the upper quartile of its distribution (1.05 mm) for SD increases in blood viscosity (P< or =.01), fibrinogen, corrected blood viscosity, and plasma viscosity (all P< or =.05). With the exception of plasma viscosity, these risks were unaffected by adjustment for other common cardiovascular risk factors. No significant associations were found between any of the hemorheological factors and IMT in women or for tPA, fibrin D-dimer, or vWF in either sex.

CONCLUSIONS

These findings suggest that in men, blood viscosity and its major determinants are associated not only with incident cardiovascular events but also with the early stages of atherosclerosis. This may be one explanation for the link between rheological factors and events.

Methane output and lactation response in Holstein cattle with monensin or unsaturated fat added to the diet

We measured effects of continuous vs twice-daily feeding, the addition of unsaturated fat to the diet, and monensin on milk production, milk composition, feed intake, and CO2-methane production in four experiments in a herd of 88 to 109 milking Holsteins. Methane and CO2 production increased with twice-daily feeding, but the CO2:CH4 ratio remained unchanged. Soybean oil did not affect the milkfat percentages, but fatty acid composition was changed. All saturated fatty acids up to and including 16:0 decreased (P < .01), whereas 18:0 and trans 18:1 increased (P < .001). The 18:2 conjugated dienes also increased (P < .01) when the cows were fed soybean oil. Monensin addition to the diet at 24 ppm decreased methane production (P < .01); the CO2:CH4 ratios reached 15, milk production increased (P < .01), and milkfat percentage and total milkfat output decreased (P < .01), as did feed consumption, compared with cows fed diets without monensin (P < .05). Milk fatty acid composition showed evidence of depressed ruminal biohydrogenation: saturated fatty acids (P < .05) decreased and 18:1 increased (P < .001); most of the increase was seen in the trans 18:1 isomer. As with soybean oil feeding, addition of monensin also increased (P < .05) the concentration of conjugated dienes. The monensin feeding trial was repeated 161 d later with 88 cows, of which 67 received monensin in the diet in the first trial and 21 cows were newly freshened and had never received monensin. Methane production again decreased (P < .05), but this time the CO2:CH4 ratio did not change and all other monensin-related effects were absent. The ruminal microflora in the cows that had previously received monensin seemed to have undergone some adaptive changes and no longer responded as before.

Haemostatic factors and prediction of ischaemic heart disease and stroke in claudicants

Thrombotic risk factors may be important in determining cardiovascular outcome in patients with symptomatic peripheral arterial disease. A cohort study with a 6-year follow-up period was established to determine the relationships between haemostatic and rheological factors and incident ischaemic heart disease (IHD) and stroke events in patients with peripheral arterial disease. A consecutive series of 607 patients with intermittent claudication was examined between 1989 and 1990 at the Peripheral Vascular Clinic, Royal Infirmary of Edinburgh. Main outcome measures were combined fatal and non-fatal stroke, non-fatal myocardial infarction (MI), coronary death and total coronary events. A total of 210 patients died during follow-up. 203 patients did not experience a vascular event or deterioration of limb ischaemia. Median levels of fibrinogen, von Willebrand factor (VWF), tissue plasminogen activator (t-PA) antigen, fibrin D-dimer and whole blood viscosity were significantly higher in those who experienced an event compared with those who did not. After adjusting for age and sex, fibrin D-dimer was significantly associated with risk of non-fatal myocardial infarction (RR 1.50, 95% CI 1.09-2.06, P < or = 0.01). Both fibrinogen and fibrin D-dimer were associated with risk of total coronary events (P < or = 0.05). The risk of stroke was related to baseline levels of t-PA antigen (RR 1.87, 95% CI 1.04-3.34, P < or = 0.05) and whole blood viscosity (RR 1.33, 95% CI 1.07-1.65, P < or = 0.01). All the relationships became weaker and statistically non-significant after further adjustment for cigarette smoking, systolic blood pressure, glucose and baseline IHD. The associations of these factors to IHD and stroke may therefore be partly related to cardiovascular risk factors, but are likely to be important in the pathogenesis of future atherothrombotic events in subjects with peripheral arterial disease.