Progression of atherosclerosis in middle-aged men: effects of multifactorial intervention

OBJECTIVE

To determine the effect of multifactorial intervention against cardiovascular risk factors on ultrasound-determined progression of atherosclerosis in healthy middle-aged men.

DESIGN

One hundred and forty-nine healthy middle-aged men were assigned to an intervention group (IG) or a control group (CG).

SUBJECTS

The participants had moderately increased risk-factor scores for cardiovascular disease. They were recruited from a health screening programme at the Preventive Medicine Section, Department of Medicine, Lund University, University Hospital, Malmö. During the study period, 32 of the subjects were lost to follow-up, leaving 59 in the IG and 58 in the CG.

INTERVENTION

The IG subjects underwent multifactorial intervention for 2 years, the goal being to help them stop smoking and to reduce their blood lipids and blood pressure.

MAIN OUTCOME MEASURES

Intima-media thickness and plaque score in the right carotid artery were ultrasonographically determined initially and after 2 years. Blood lipids and blood pressure were measured at the same time, and in the IG also after 3, 6, 12 and 18 months after entry into the study.

RESULTS

At the entry into the study, there were no significant differences in major risk factors or ultrasound variables between IG and CG. Blood lipids and smoking decreased significantly during the 2 years of intervention in the IG, whilst these factors remained unchanged in the CG. Intima-media thickness and plaque scores increased significantly in both groups.

CONCLUSIONS

No effects on ultrasound variables could be detected after 2 years of multifactorial intervention. A more aggressive intervention programme, possibly more dependent on pharmacological treatment, may be required to obtain reduced progression or regression of atherosclerosis.

Organotellurium compounds as efficient retarders of lipid peroxidation in methanol

Diaryl tellurides were found efficiently to retard azo-initiated lipid peroxidation of linoleic acid in methanol. The most efficient compounds, 31 and 39, contained one and two hydroxyl groups, respectively, in the para positions and methyl groups in all four positions ortho to tellurium. As determined by the values of n.kinh, these materials were as effective retarders of lipid peroxidation as vitamin E. Contrary to the conventional antioxidants examined, diaryl tellurides were found to inhibit peroxidation for long times, seemingly with an autocatalytic mechanism. Diaryl tellurides were found to be partially oxidized during the peroxidation. The reduction of tellurium (IV) compounds to the divalent state during the conditions of the experiment is discussed. The reactivity of some diaryl chalcogenides toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) in methanol was studied. All compounds investigated were less reactive than vitamin E. One of the most active organotellurium compounds, bis(4-aminophenyl) telluride, reacted considerably faster with DPPH than the corresponding selenide or sulfide. It was concluded that mechanisms involving both hydrogen atom transfer and electron transfer were operative in the reaction of organotellurides with DPPH.

Central nervous system effects of subdissociative doses of (S)-ketamine are related to plasma and brain concentrations measured with positron emission tomography in healthy volunteers

Plasma concentrations, maximum regional brain concentrations, and specific regional binding in the brain after administration of 0, 0.1, and 0.2 mg/kg doses of (S)-ketamine were measured in a randomized, double-blind, crossover study in five volunteers and were related to induced effects such as analgesia, amnesia, and mood changes. Specific binding in the brain was assessed by simultaneous administration of (S)-[N-methyl-11C]ketamine quantified by positron emission tomography. High radioactivities in the brain corresponded to regional distribution of N-methyl-D-aspartate receptor complexes. A significant and dose-dependent reduction of binding was measured as a result of displacement of (S)-[N-methyl-11C]ketamine. Memory impairment and psychotomimetic effects were related to dose, plasma concentration 4 minutes after administration, and decreased regional binding of (S)-ketamine in the brain and were consistently seen at plasma and maximum regional brain (S)-ketamine concentrations higher than 70 and 500 ng/ml, respectively. The magnitude of specific binding of (S)-ketamine, measured with positron emission tomography, can be related directly to drug effects.

Technology and disability. Assessment needs and potential

In assessing technologies for disabled people, the aims of habilitative or rehabilitative interventions, the concepts of disability and handicap, and the potential of existing and emerging technologies in various social arenas, as well as the structure of service delivery systems, are of importance. A discussion of these issues in the light of previous work on cost and effectiveness in the field is given.

Assessment of rehabilitation technologies in stroke. Outcomes and costs

Initial functional ability (Barthel Index, mean 57) was found to be an important predictor of functional ability 1 year after stroke (mean 80) and for costs during the period. On average the total cost for a stroke patient was about SEK 200,000; the main expense, accommodation, averaged about SEK 140,000, while assistive devices amounted to SEK 2,600. Those who use assistive devices, although having achieved a high functional ability, perceive and rate their life situation (Nottingham Health Profile) considerably more impaired than those without assistive devices.

Cost-utility analysis of assistive technologies in the European Commission's TIDE Program. Technology Initiative for Disabled and Elderly People

Socioeconomic evaluation is an issue dealt with in the European Commission's research program TIDE. The principles of cost-utility analysis have been examined for usability in the assessment of rehabilitative technologies. A case study, the choice of a type of wheelchair, is described to demonstrate how estimates of utility can be derived and how cost-utility ratios can be used to guide decision making.

The cost of the Swedish handicap service system. Implications for technology assessment

The total cost of the Swedish handicap system is estimated at US $10.7 billion for 1989. The cost is distributed across different authorities with separate legal and financial responsibility. The concept of technology must be extended to include consideration of both the resources spent and benefits gained in the public sector and the magnitude and distribution of transfer payments from social insurance to fulfill its function in handicap policy decision making.

Helicobacter pylori, active chronic antral gastritis, and gastrointestinal symptoms in alcoholics

The frequency of Helocobacter pylori (Hp.) infection and active chronic antral gastritis among people with excessive alcohol consumption is not known. A high alcohol intake regularly causes acute gastroduodenitis. In this study, the prevalence of Hp. infection and active chronic antral gastritis in alcoholics compared with nonalcoholic controls was studied. Further, the frequency of gastrointestinal symptoms was registered. Diagnostic methods for Hp. were compared. Twenty-four alcoholics admitted to the hospital for detoxification underwent upper gastrointestinal endoscopy regardless of symptoms. Twelve individuals admitted to upper endoscopy mainly for dyspepsia, with low alcohol consumption and without gross pathology by upper endoscopy, were chosen as controls. Three diagnostic methods for Hp. were used: culture, direct microscopy, and histology. Hp. infection was found in 7 of the 24 alcoholics (29%) according to culture. In controls, 4 of 12 (33%) had a positive Hp. culture. In the alcoholic group, culture was more sensitive than histology. There was a good correlation between the different diagnostic methods in the control group. Histologically active chronic antral gastritis was found in 6 of the alcoholics (25%) and in 5 of the controls (42%). Five of the 7 Hp.-positive alcoholics and all of the Hp.-positive controls had an active chronic antral gastritis. Hp. infection is not more frequent in alcoholics than in controls. In both groups, there was a good correlation between Hp. infection and histologically, active chronic antral gastritis.

Diaryl tellurides as inhibitors of lipid peroxidation in biological and chemical systems

Diaryl tellurides carrying electron-donating substituents in the para positions were found to efficiently inhibit peroxidation of rat hepatocytes, rat liver microsomes and a chlorobenzene solution of phosphatidylcholine. The most active compound in the microsomal assay, bis(4-dimethylaminophenyl) telluride, showed an IC50-value of 30 nM. This compound also caused a dose-dependent delay of the onset of the linear phase of microsomal peroxidation stimulated by iron/ADP/ascorbate. The peak oxidation potentials of the diaryl tellurides (0.50-1.14 V in MeCN) correlated linearly with the IC50-values in this assay, with a point of inflection around 0.85 V. In the hepatocyte system, all compounds showed similar protective activity. It is proposed that diaryl tellurides exert an antioxidative effect by deactivating both peroxides and peroxyl radicals under the formation of telluroxides. These oxides may regenerate the active divalent organotellurides upon exposure to a suitable reducing agent.

An electron microscope and electron diffraction study of the effect of calcofluor and congo red on the biosynthesis of chitin in vitro

The structure of chitin made in vitro by chitin synthetase was studied by electron microscopy and electron diffraction. Two different forms of chitin synthetase from the fungus Mucor rouxii were tested: chitosomes and 16 S particles. The long chitin fibrils produced by chitosomes had a high degree of crystallinity as revealed by electron diffraction. Specimen regions made of largely parallel microfibril bundles produced distinct fiber diagrams, an indication that the chitin chains were aligned along the fibril axis. Microdiffractometry of the shorter chitin crystals synthesized by 16 S particles also showed a similar alignment of chitin chains. Calcofluor and Congo red were powerful inhibitors of chitin synthetase and had profound effects on the color, macroscopic texture, electron microscopic morphology, and crystal structure of the biosynthesized chitin. Chitin made in the presence of Congo red had a bright red color; the one made in the presence of Calcofluor was strongly fluorescent and had a distinctly blue hue when illuminated by daylight. The dyes were tightly bound to the chitin and could not be removed by washing with water or ethanol. At low dye concentration, a mixture of two kinds of crystals was produced by 16 S particles: some were of the same dimensions as those made in the absence of dyes, but others were much thinner. At high dye concentration, there were only thin crystals. With increasing concentrations of Calcofluor or Congo red, the typical electron diffraction reflections of alpha-chitin, particularly the strong equatorial band at 0.466 nm became fainter and a new additional reflection centered at 0.40 nm arose as the dominant feature of the patterns. We regard the gel-like material, synthesized at highly inhibitory dye concentrations, as an apposition complex where the dye does not form part of the crystal structure of chitin and the bulk of the complex consists of molecular stacks of dye associated with nascent chitin chains or narrow chitin microfibrils.

Clinical experience with minimal flow xenon anesthesia

Xenon is a more potent anesthetic than nitrous oxide, and give more profound analgesia. This investigation was performed to assess the potential of xenon for becoming an anesthetic inspite of its high manufacturing cost. Seven ASA I-II patients undergoing cholecystectomy (n = 4), hernia repair (n = 2), or mammoplasty (n = 1) were studied. Denitrogenation by 15-20 min of oxygen breathing under propofol anesthesia was followed by fentanyl-supplemented xenon anesthesia administered via an automatic minimal flow system which held the oxygen concentration at 30%. Xenon anesthesia lasted 76-228 min and 8-14 l of xenon (ATPD) was used, of which 5.6-8.1 l was expended during the first 15 min. Anesthesia appeared to be satisfactory, and the patients woke up rapidly after xenon was discontinued. The automatic system made minimal flow xenon anesthesia easy to administer, but nitrogen accumulation is still a problem. Assuming a xenon price of 10 US$ per litre, the average cost for xenon was about 65 US$ for the first 15 min and then about 25 US$ for each subsequent hour of anesthesia.

Ultrasound-determined intima-media thickness and atherosclerosis. Direct and indirect validation

To evaluate ultrasonographically determined intima-media thickness as a measure of early atherosclerosis, three studies were performed. Ultrasound measurements of intima-media thickness in the carotid artery were directly validated by comparing the same thickness measured by light microscopy. The values were closely correlated (r = .82, P < .001). Intima-media thickness determined by light microscopy was consistently smaller than that determined by ultrasound, probably due to shrinkage during histological preparation. As an indirect validation, mean intima-media thickness was calculated in three large groups of patients with no plaque (n = 224), one plaque (n = 105), and one circumferential or two or more plaques (n = 54) in the carotid bifurcation. Intima-media thickness increased significantly with increasing plaque score, indicating that diffuse intima-media thickening is more pronounced with more severe atherosclerosis. The intima-media thickness also increased with increasing multifactorial cardiovascular risk, reflecting a positive relation between signs of early atherosclerosis and the burden of known risk factors for the disease. Our studies support earlier findings that have found that ultrasonographically determined intima-media thickness is a valid way to study early atherosclerosis.

Gamma-L-glutamyl-L-glutamate is an endogenous dipeptide in the rat olfactory bulb which activates N-methyl-D-aspartate receptors

The concentration of gamma-L-glutamyl-L-glutamate (gamma-glu-glu), a potent displacer of excitatory amino acid receptor binding, and other structurally related dipeptides were determined in extracts of the rat olfactory bulb by a novel liquid chromatographic method. Whole-cell patch clamp recordings of currents from freshly isolated neurons showed that gamma-glu-glu produced inward currents at negative holding potentials, provided microM concentrations of glycine were added and no Mg(2+)-ions were present, indicating activation of N-methyl-D-aspartate receptors. Consistently, geometry optimization of gamma-glu-glu using molecular mechanics calculations, suggested a bent conformer with structural features supporting this view.

Work organisation, work environment and the use of medical equipment: a survey study of the impact on quality and safety

In a study of hospital staff's perceived quality of care and worry, related to the use of medical equipment, a systems approach was used. This included training and user aspects on the equipment, environmental ergonomics, work organisation and psychosocial work conditions. In a survey study, 543 hospital staff members from seven departments with various degrees of equipment utilisation participated. By means of factor analysis, factors which were important to perceived quality of care and worry were determined. Adaptation of equipment and environment and training on the use of equipment were shown to be important. However, several organisational and psychosocial factors turned out to have a still greater impact. In the assessment of healthcare technologies which include medical equipment a holistic systems approach is therefore advocated.

Noninvasive quantification of atherosclerotic lesions. Reproducibility of ultrasonographic measurement of arterial wall thickness and plaque size

A noninvasive method based on high-resolution B-mode ultrasonography and a computerized image-analyzing system were used for the quantification of early (thickening of the intima-media complex) and late (plaque) atherosclerosis in the carotid and the femoral artery. The difference between repeated measurements was assessed to estimate intraobserver and interobserver differences. The results were satisfactory, with a coefficient of variation for measurement of lumen diameter in the common carotid artery of 3.8 +/- 4.1% (r = 0.91) and for the femoral artery of 4.8 +/- 4.1% (r = 0.93). Corresponding figures for intima-media thickness in the common carotid artery and the femoral artery were 10.0 +/- 8.5% (r = 0.86) and 16.2 +/- 12.6% (r = 0.91), respectively. The coefficient of variation for measurements of maximal intima-media thickness at the site of the plaque was 14.6 +/- 10.5% (r = 0.88); for plaque base, 13.1 +/- 9.0% (r = 0.91); and for plaque area, 16.3 +/- 12.6% (r = 0.90). The method seems promising for the detection and quantification of early and late atherosclerotic lesions in the carotid and femoral arteries.

Effect of pancreatic phospholipase A2 and gastric lipase on the action of pancreatic carboxyl ester lipase against lipid substrates in vitro

Preincubation of a triolein/phospholipid/cholesteryl oleate-emulsion in vitro with either pancreatic phospholipase A2 (PLA2) or gastric lipase (GL) resulted in hydrolysis (measured by pH-stat-titration) of cholesteryl [3H]oleate only after human pancreatic carboxyl ester lipase (CEL) was added to the system. No appreciable hydrolysis was observed when CEL was added alone. Consequently, a concerted action either of PLA2 and CEL or of GL and CEL made the substrate cholesteryl oleate available for hydrolysis by CEL. This was the case when cholesteryl oleate was solubilised in a phospholipid-stabilised triglyceride emulsion, which is the physico-chemical form in which the major part of dietary cholesteryl esters are presented to the gastro-intestinal tract of man.

Alcohol and the small intestine

Several alterations of the small-intestinal morphology and function have been documented after alcohol ingestion. There are morphologic changes macroscopically and microscopically after acute alcohol administration in the proximal part of the small intestine, which are quickly reversible. There are no macroscopic changes and, in most patients, very discrete light microscopic changes in the small intestine after chronic alcohol ingestion. The ultrastructural changes are, however, profound, as seen by both transmission and scanning electron microscopy. The permeability is probably increased, permitting entrance of possible noxious agents, which may explain some of the extraintestinal tissue damage observed in chronic alcoholism. The transit is increased, at least after acute alcohol administration, perhaps contributing to the diarrhea commonly seen after heavy drinking. Several of the enzymes located in the brush border are affected; lactase activity can be depressed and perhaps result in a transient milk intolerance in predisposed individuals. The activity of GGT is increased and may partly account for the GGT elevation in serum after heavy drinking. Other enzymes, such as Na(+)-K(+)-ATPase, can be inhibited and result in a decreased absorption of substances that require active, energy-dependent transport mechanisms. The secretion of water and electrolytes may be increased (an effect on cAMP?). The absorption of several nutrients, vitamins, and other elements is disturbed. The bacterial flora is increased and changed, which may give rise to symptoms and also increase the production of acetaldehyde by bacterial metabolism of ethanol. Acetaldehyde is more toxic than ethanol, and an increased concentration of acetaldehyde can possibly accentuate the damage to the liver and other organs. The bacterial overgrowth can possibly cause endotoxinemia. Although studies on alcohol-related intestinal alterations have been relatively sparse, the acute and chronic effects of alcohol thus seem to be considerable. From available results it is, however, difficult to draw any definite conclusions about the clinical importance of many of the findings. Future research will need to study the relationship between, for example, the chronic morphologic changes, the absorptive dysfunction, and permeability alterations, on the one hand, and the gastrointestinal symptoms, the extraintestinal damage, and various deficiencies, on the other hand.

Serum gamma-glutamyl transferase (GGT) in a group of organized teetotallers

Organized teetotalers were examined with regard to gamma-glutamyl transferase (GGT) in the serum. The mean values for GGT in the group of teetotalers (0.32 mukat/l +/- 0.23) was considerably lower compared with a group of the general population (0.50 mukat/l +/- 0.48), p less than 0.001. Only a few teetotalers had GGT values more than 1.0 mukat/l. A certain tendency to higher values was found among middle-aged men compared to women. No statistically significant correlation between GGT and age was found.

Morphologic changes in the small intestine after chronic alcohol consumption

The morphology of the small-intestinal mucosa was studied in 11 alcoholic patients admitted to hospital for detoxification. A first biopsy specimen from the small intestine was taken as soon as possible after admission and a second specimen after about 6 weeks of abstinence. The specimens were studied in the light microscope, in the scanning electron microscope, and by immunohistochemistry. Morphometrically, a slight reduction in villus height in relation to crypt depth was observed. One patient had a subtotal villus atrophy. After abstinence the villus height was increased in five of the six patients who accepted a second biopsy. No obvious changes were seen in the frequency and appearance of peptidergic nerves or endocrine cells. Ultrastructurally, pronounced alterations were seen in the surface ultrastructure of the enterocytes. In two specimens bacterial adhesion to the mucosal surface was also found. The ultrastructural changes were unaltered after abstinence. In serum the concentrations of zinc were reduced, and the levels of copper were elevated compared with a group of teetotallers. A recently developed marker of high alcohol consumption, carbohydrate-deficient transferrin, was as good an indicator as the other conventional biochemical markers.

Sickness absenteeism and mortality in patients with excessive drinking in somatic out-patient care

In a study of 2114 patients attending somatic outpatient clinics, 208 were classified as excessive drinkers. Sickness benefit days and sickness periods per year, disability pension, and mortality were studied for the years 1981 to 1985. The excessive drinkers as a group had 13 to 27 more sickness days per year than the other patients. They also had more sickness periods and a higher rate of disability pension than patients without alcohol overconsumption. The study thus showed that a group with varying degrees of excessive drinking had an increased need for sickness benefits. The mortality was considerably increased among the excessive drinkers. The patients who had undergone treatment or were registered because of alcohol problems had most sickness benefit days. The excessive drinking patients without advanced alcohol problems did not have more sickness days than the other patients. Most of these patients (75%) were sick-listed without recognition of their excessive drinking by their doctor. This emphasizes the importance, in terms of sickness benefits and mortality, of better identification of patients with excessive drinking.

Teaching medical informatics to biomedical engineering students: experiences over 15 years

The Departments of Biomedical Engineering and Medical Informatics at Linköping University in Sweden were established in 1972-1973. The main purpose was to develop and offer courses in medicine, biomedical engineering and medical informatics to students in electrical engineering and computer science, for a specialization in biomedical engineering and medical informatics. The courses total about 400 hours of scheduled study in the subjects of basic cell biology, basic medicine (terminology, anatomy, physiology), biomedical engineering and medical informatics. Laboratory applications of medical computing are mainly taught in biomedical engineering courses, whereas clinical information systems, knowledge based decision support and computer science aspects are included within the medical informatics courses.

Early intervention in patients with excessive consumption of alcohol: a controlled study

From a population of 2,114 patients attending somatic outpatient clinics, 78 patients were selected who had either an excessive consumption of alcohol according to questionnaires or a raised gamma glutamyltransferase (GGT) value (above 0.6 mu kat/l) due to alcohol. They had not undergone treatment for problem drinking previously, and had no serious alcohol dependence. They were thereby classified as excessive consumers of alcohol, and randomly allocated to an intervention (n = 36) or to a control group (n = 42). Those in the intervention group were followed up by a nurse once a month and by a doctor every third month for a total of 12 months. Laboratory tests were taken monthly. Consumption of alcohol, GGT and triglyceride levels, and sickness allowance days were decreased in the intervention group compared to the time before intervention. In contrast, the number of sickness allowance days in the control group increased. There was also a tendency towards a positive effect of intervention on the number of consultations made with a statistically not significant decrease of consultations after intervention. The study thus indicates that an early and relatively simple intervention programme for problem drinkers may be effective and can be carried out at a low cost and with a positive response from the patients.

Can villous atrophy be induced by chronic alcohol consumption?

A 43-year-old man presented with loose stools, abdominal pain and a weight loss of 15 kg. Investigations revealed a pancreatic insufficiency and an enteropathy with villous atrophy. Coeliaki was suspected. In spite of treatment with a gluten-free diet in hospital the patient did not improve and the villous atrophy remained unchanged. Other causes than coeliaki to villous atrophy were ruled out. The patient had a heavy consumption of alcohol and after prolonged abstinence the patient gained weight, the pain disappeared and the stools were normalized. The jejunal biopsy was now normal. This case report raises the possibility that enteropathy and villous atrophy may be causally related to alcohol overconsumption.

Diffusion of medical devices in primary health care in Sweden

An inventory of the availability of medical devices and laboratory tests at primary health care centers in Sweden is reported. The availability is shown to depend on a number of medical, economic, societal, and organizational factors describing primary health care. Technical performance of devices, risk management, and training of users need special attention with regard to these applications.

Specific and nonspecific regeneration of motor axons after sciatic nerve injury and repair in the rat

The pattern of motor axon regeneration following unilateral sciatic nerve lesions (freezing or transection) was studied in adult rats. Transected nerves were repaired with epineurial or fascicular sutures. Four months after the lesion, the motor neuron cell body localization in the spinal cord of plantar or common peroneal nerve axons were examined bilaterally with retrograde transport of horseradish peroxidase. Motor neuron cell body localization was similar bilaterally after freezing, indicating that regenerating axons had reached their original peripheral innervation territory. However, after nerve transection, irrespective of whether epineurial or fascicular sutures were used, motor neuron cell body distribution on the operated side was abnormal with numerous labeled cell bodies located outside the area of the normal motor neuron pool. This finding indicates that after nerve transection the normal pattern of motor axon innervation is not restored even after fascicular nerve repair.

Prevalence of excessive or problem drinkers among patients attending somatic outpatient clinics: a study of alcohol related medical care

The prevalence of alcohol related morbidity was studied among 2038 patients attending somatic outpatient clinics. A further 76 patients had refused the study, giving an overall drop out rate of 3.6%. Several methods were combined so as to detect as many patients with problem drinking as possible. According to the criteria and definitions employed 17% of men (confidence interval 15% to 19%) and 4% of women (confidence interval 3% to 5%) were excessive consumers of alcohol or problem drinkers. The highest proportion of such patients--that is, 17%--was noted in the emergency rooms (27% of men, 8% of women). At other clinics the proportions varied from 11% to 17% of men and from 2% to 4% of women. The strongest relations between overconsumption of alcohol and consultation at the clinic were among patients attending the medical outpatient clinic and the emergency rooms; in 86% (confidence interval 75% to 97%) and 88% (confidence interval 81% to 95%) of problem drinkers attending these clinics, respectively, alcohol was related to the consultation. Consultations were related to alcohol in 82% of women with excessive or problem drinking and 73% of men defined in this way. There was a tendency to a higher proportion of men with excessive or problem drinking in the age group 40-49 years. These findings show that among patients classified as excessive or problem drinkers attending somatic outpatient clinics there was a close relation between alcohol consumption and utilisation of medical resources, especially in women.

Causes of elevated serum gamma-glutamyl transferase in patients attending outpatient somatic clinics and district health centres

In this study of 1985 patients in somatic outpatient care (medicine, surgery, orthopedics, emergency and primary health care clinics), 231, or 11.6%, were found to have an elevated serum GT value (above 0.9 mukat/l). Alcohol was the cause of this in approximately one third of the cases, while diseases and drugs were the underlying cause in the other cases. In the population, there were 208 alcohol-overconsuming patients (163 men and 45 women) and 28 patients had a serum GT elevation which led to detection of a previous unknown alcohol problem or excessive consumption. The mean and median value for serum GT for the alcohol patients was markedly higher than in the non-alcohol-overconsuming group. The sensitivity for serum GT (with a value of 0.9) as regards alcohol consumption was 40%. The GT test screened 4.2% of patients with excessive alcohol consumption of which one third were "hidden".

Assessing technology for rehabilitation. Three cases and three countries

The rehabilitation field has not always been regarded as the most glamorous or commercially promising section of medical care. But changing attitudes and demographics in many industrial countries have led to increased recognition of opportunity to provide services for individuals with disabilities and those in need of chronic care. As hospitals are under increasing pressure to offer rehabilitation services, this article focuses on three different technologies developed in three different countries, Sweden, the United Kingdom, and the United States.

Labeling of cutaneous sensory nerve endings with axonally transported horseradish peroxidase and wheat germ agglutinin-horseradish peroxidase conjugate: a methodological study in the rat

Practical aspects on the use of horseradish peroxidase (HRP) and wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) to trace peripheral cutaneous nerve endings have been studied. The parameters studied included application site of the tracer, post-application survival time, tracer concentration and tracer volume. These parameters were examined in the glabrous skin of the rat hindpaw. The best results were obtained with injections of 1 microliter WGA-HRP (20 micrograms/microliter) in dorsal root ganglia innervating the examined cutaneous region and a postinjection survival time of 18-36 h. With this approach extensive and heavy labeling was achieved of epidermal nerve endings, nerve endings in Merkel cell-neurite complexes and Meissner corpuscles. Useful, but less extensive labeling of these types of peripheral nerve endings, was obtained with injections of HRP in the lumbar spinal cord dorsal horn.

Physiological and psychological indices of fatigue during static contractions

The development of fatigue and the relationship between psychological and physiological indices of fatigue were studied in a group of 18 male subjects during static contractions. Exercise was performed as a static elbow flexion at 25% MVC. Heart rate (HR), intraarterial blood pressure (BP) and surface EMG [mean amplitude (MA) and central frequency (CF)] were studied during contractions sustained until exhaustion. The amount of effort expended (relative to total exhaustion) and the rating of perceived pain were recorded following contractions interrupted after 20, 30 . . . 80, and 100% of endurance time. HR, BP and EMG amplitude responses were similar to those previously recorded. The decline in CF occurred in two phases, possibly related to a change in motor unit recruitment after the initial 70% of endurance time. The subjects overestimated the amount of effort expended and thus underestimated their endurance capacity. The best correlation between perceived effort and physiological responses was obtained using blood pressure data, whereas changes in EMG data did not parallel the psychological responses. It is concluded that the perception of effort during a static contraction is produced through a complex process, in which several influences of peripheral and central origin are integrated.

Leg blood flow during static exercise

Leg blood flow was studied with the constant infusion dye technique during static exercise of the thigh muscles (quadriceps) and during hand-grips at 15 and 25-30% of MVC. Blood flow and oxygen uptake in the leg increased in quadriceps exercise and reached their highest values (around 1.21/min and 165 ml/min respectively) at 25-30% of MVC, whereas leg vascular resistance decreased. Regional circulatory adaptations and the oxygen uptake - leg blood flow relationship were in close agreement with the responses found in dynamic leg exercise. In view of the marked rise in intramuscular pressure previously observed during quadriceps contractions, a restriction of blood flow and an increased vascular resistance had been expected. Involuntary activation of leg muscles other than the quadriceps may explain the finding. Contractions of the contralateral quadriceps induced a slight increase in leg blood flow, whereas hand-grips had no influence on blood flow or vascular resistance in the leg. The distribution of the cardiac output during static contractions is discussed, and it is concluded that during hand-grips the increase in blood flow is predominantly distributed to the upper part of the body.

The influence of day and night work on the circadian variations of cardiovascular performance

Circadian variations of the pre-ejection period, Q-T interval, heart rate and oral temperature at rest and in day and night shift work were investigated. At rest, pronounced circadian variation was found in heart rate, pre-ejection period and Q-T interval. The ratio between Q-T interval and heart rate also shows a distinct circadian variation. When working, the rest rhythms of the variables were obscured. The physiological implications for shift work are discussed.

Cardiovascular response to combined dynamic and static exercise

The cardiovascular response to combined static handgrip at 20% MVC and dynamic leg exercise was studied in young male subjects. Cardiac output increased by 2.3 liters/min (30%) at isolated handgrip and by 1.0 liter/min (7%) when handgrip was added to dynamic exercise at 100 W. In spite of an increased arterial blood pressure, leg blood flow was unaffected by handgrip, both when it was performed isolated and in combination with dynamic exercise. Temperature measurements in mixed venous blood and subcutaneous tissue indicated an increased blood flow to peripheral circulatory areas. During combinations of handgrip and dynamic exercise at different levels of VO2, heart rate response to handgrip was progressively less marked as maximal oxygen uptake was approached. Therefore a vagal withdrawal seems to be the most important heart rate-increasing mechanism during combined exercise. Systolic blood pressure response to handgrip was still preserved at 25 and 45% of max VO2. At 95% of max VO2, the blood pressure response to handgrip was abolished, probably due to a competitive utilization of the same blood pressure-raising mechanism in dynamic and static exercise.