Changes in cortical extracellular levels of energy-related metabolites and amino acids following concussive brain injury in rats

The aim of this study was to measure extracellular chemical changes in the cerebral cortex in response to compression contusion trauma in rats. Energy-related metabolites (i.e., lactate, pyruvate, adenosine, inosine, and hypoxanthine) and amino acids were harvested from the extracellular fluid (ECF) using microdialysis and analyzed by high-performance liquid chromatography. The measurements were performed in cortical tissue, where neuronal injury occurs in this model. The severity of the trauma was varied by using different depths of impact: mild trauma, 1.5 mm; severe trauma, 2.5 mm. The trauma induced a dramatic increase in the ECF levels of energy-related metabolites that was conditioned by the severity of the insult. The ECF level of taurine, glutamate, aspartate, and gamma-aminobutyric acid (GABA) also rose markedly, while other amino acids did not change significantly. The results suggest that the trauma induced a transient, profound focal disturbance of energy metabolism in the cortical tissue, probably as a result of mechanically induced disruption of ion homeostasis and reduced blood flow in combination. The data support the potential role of glutamate and aspartate as mediators of traumatic brain injury. However, the concomitantly released adenosine, GABA, and taurine may be protective and ameliorate excitotoxicity. In analogy with the reported cumulative damaging effects of repeated ischemic insults, the observed ECF changes may help explain the vulnerability of traumatized brain tissue to secondary ischemia.

Low-molecular-weight heparin (enoxaparin) as prophylaxis against venous thromboembolism after total hip replacement

BACKGROUND

The risk of venous thromboembolism in patients undergoing total hip replacement is known to be high. However, the optimal duration of prophylaxis with anticoagulant agents after this procedure is unknown. We sought to determine whether one month of anticoagulant therapy with the low-molecular-weight heparin enoxaparin is more effective than enoxaparin therapy given only during the hospitalization for surgery.

METHODS

Two hundred sixty-two patients undergoing total hip replacement received enoxaparin during their hospitalizations (average stay, 10 to 11 days). They were then randomly assigned to receive enoxaparin or placebo (131 patients each). Blinded outpatient therapy (or placebo) was continued long enough that the total treatment period, inpatient plus outpatient, was one month for each patient. Bilateral ascending phlebography was performed 19 to 23 days after discharge, with deep-vein thrombosis as the primary end point. Distal and proximal thrombosis, pulmonary embolism, and hemorrhage were also recorded, as were deaths.

RESULTS

Venography was adequate in 116 patients in the placebo group and 117 in the enoxaparin group. We observed 43 episodes of deep-vein thrombosis and 2 episodes of pulmonary embolism in the placebo group, but only 21 episodes of deep-vein thrombosis and no episodes of pulmonary embolism in the enoxaparin group (incidence of thromboembolism, 39 percent and 18 percent, respectively; P<0.001). The difference in the incidence of proximal deep-vein thrombosis was also significant (24 percent and 7 percent in the placebo and enoxaparin groups, respectively; P<0.001). Six enoxaparin groups, respectively; P<0.001). Six patients in the enoxaparin group and one patient in the placebo group had hematomas at their injection sites. No patients died or had major complications.

CONCLUSIONS

There were significantly fewer venous thromboembolic complications in patients undergoing elective hip replacement when prophylaxis with enoxaparin was given for a total of one month, rather than only during the hospitalization.

A transcriptional roadmap to wood formation

The large vascular meristem of poplar trees with its highly organized secondary xylem enables the boundaries between different developmental zones to be easily distinguished. This property of wood-forming tissues allowed us to determine a unique tissue-specific transcript profile for a well defined developmental gradient. RNA was prepared from different developmental stages of xylogenesis for DNA microarray analysis by using a hybrid aspen unigene set consisting of 2,995 expressed sequence tags. The analysis revealed that the genes encoding lignin and cellulose biosynthetic enzymes, as well as a number of transcription factors and other potential regulators of xylogenesis, are under strict developmental stage-specific transcriptional regulation.

Deletions of the heavy neurofilament subunit tail in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degeneration resulting in paralysis and death, usually within 3 years of onset. Pathological and animal studies implicate neurofilament involvement in ALS, but whether this is primary or secondary is not clear. The heavy neurofilament subunit (NFH) tail is composed of a repeating amino acid motif, usually X-lysine-serine-proline-Y-lysine (XKSPYK), where X is a single amino acid and Y is one to three amino acids. There are two common polymorphic variants of 44 or 45 repeats. The tail probably regulates axonal calibre, with interfilament spacing determined by phosphorylation of the KSP motifs. A previous study suggested an association between sporadic cases of ALS and NFH tail deletions, but two subsequent studies have found none. We have analysed samples from two different populations (UK 207, Scandinavia 323) with age-matched controls for each group (UK 219, Scandinavia 228) and have found four novel NFH tail deletions, each involving a whole motif. These were found in three patients with sporadic ALS and a family with autosomal dominant ALS, although another was also found in two young controls. In all cases motif deletions were only associated with disease when paired with the long NFH allele. The deletions all occurred within a small region of the NFH tail. This has allowed us to propose a structural organization of the tail as well as allowing observed deletions both from this study and previous reports to be organized into logical groups. These results strongly suggest that NFH motif deletions can be a primary event in ALS but that they are not common.

Relation between insulin resistance and carotid intima-media thickness and stenosis in non-diabetic subjects. Results from a cross-sectional study in Malmö, Sweden

AIMS

To assess whether there is an association between insulin resistance and carotid intima-media thickness and stenosis in non-diabetic subjects free from symptomatic cardiovascular disease.

METHODS

A cross-sectional population-based study in Malmö, Sweden, of 4,816 (40% men) subjects, born 1926-1945. The prevalence of insulin resistance was established by the homeostasis model assessment (HOMA) and defined as values above the 75th percentile. Criteria issued by the European Group for the Study of Insulin Resistance (EGIR) were used for the definition of the insulin resistance syndrome. Common carotid artery intima-media thickness (IMT) and carotid stenosis (> 15%) were measured by B-mode ultrasonography.

RESULTS

Age and sex-adjusted common carotid IMT among subjects with the insulin resistance syndrome (12.7%) and controls was 0.812 mm, respectively, 0.778 mm (P < 0.001). The prevalence of stenosis in the two groups was 22.9 and 19.2% (P = 0.040). Insulin resistance per se was after adjustment for age and sex associated with increased IMT (0.780 mm vs. 0.754 mm, P < 0.001). This association disappeared, however, when other factors included in the insulin resistance syndrome were taken into account.

CONCLUSIONS

Fasting serum insulin covaries with a number of factors and conditions known to influence the development of atherosclerosis. It is concluded that the association between insulin resistance, as assessed by the HOMA method in non-diabetic subjects, and atherosclerosis is explained by its covariance with established risk factors for cardiovascular disease of which hypertension seems to be the most significant.

Transcriptional silencing and thermoregulation of gene expression in Escherichia coli

Expression of specific adhesive properties by bacteria in general seems to be regulated to fit the environmental conditions. An example is the transcriptional regulation of digalactoside-specific binding by uropathogenic strains of Escherichia coli. The fimbrial structures (pili) on the bacterial surface carry the adhesin and are present during growth at 37 degrees C but are not produced by cells at lower temperatures, such as 25 degrees C. Thermoregulation of expression is due to temperature-dependent transcription of a regulatory cistron in the pilus-adhesin gene cluster. We have now identified and characterized a new regulatory locus (drdX) and show that a histone-like bacterial protein has an important role in this novel example of thermoregulation of transcription.

Regional changes in interstitial K+ and Ca2+ levels following cortical compression contusion trauma in rats

Brain trauma is associated with acute functional impairment and neuronal injury. At present, it is unclear to what extent disturbances in ion homeostasis are involved in these changes. We used ion-selective microelectrodes to register interstitial potassium ([K+]e) and calcium ([Ca2+]e) concentrations in the brain cortex following cerebral compression contusion in the rat. The trauma was produced by dropping a 21 g weight from a height of 35 cm onto a piston that compressed the cortex 1.5 mm. Ion measurements were made in two different locations of the contused region: in the perimeter, i.e., the shear stress zone (region A), and in the center (region B). The trauma resulted in an immediate increase in [K+]e from a control level of 3 mM to a level > 60 mM in both regions, and a concomitant negative shift in DC potential. In both regions, there was a simultaneous, dramatic decrease in [Ca2+]e from a baseline of 1.1 mM to 0.3-0.1 mM. Interstitial [K+] and the DC potential normalized within 3 min after trauma. In region B, [Ca2+]e recovered to near control levels within 5 min after ictus. In region A, however, recovery of [Ca2+]e was significantly slower, with a return to near baseline values within 50 min after trauma. The prolonged lowering of [Ca2+]e in region A was associated with an inability to propagate cortical spreading depression, suggesting a profound functional disturbance. Histologic evaluation 72 h after trauma revealed that neuronal injury was confined exclusively to region A. The results indicate that compression contusion trauma produces a transient membrane depolarization associated with a pronounced cellular release of K+ and a massive Ca2+ entry into the intracellular compartment. We suggest that the acute functional impairment and the subsequent neuronal injury in region A is caused by the prolonged disturbance of cellular calcium homeostasis mediated by leaky membranes exposed to shear stress.

Amyotrophic lateral sclerosis associated with homozygosity for an Asp90Ala mutation in CuZn-superoxide dismutase

Recent reports have shown heterozygosity for some twenty different mutations in the CuZn-superoxide dismutase (CuZn-SOD) gene in familial amyotrophic lateral sclerosis (FALS), and analysed samples from patients have shown decreased enzymic activity. Here we report homozygosity for an exon 4 mutation, Asp90Ala in fourteen patients among four unrelated ALS families and four apparently sporadic ALS patients from Sweden and Finland. The erythrocyte CuZn-SOD activity is essentially normal. Our findings suggest that this CuZn-SOD mutation causes ALS by a gain of function rather than by loss, and that the Asp90Ala mutation is less detrimental than previously reported mutations.

Imaging in chronic achilles tendinopathy: a comparison of ultrasonography, magnetic resonance imaging and surgical findings in 27 histologically verified cases

OBJECTIVE

To compare information gained by ultrasonography and magnetic resonance imaging (MRI) in chronic achilles tendinopathy with regard to the nature and severity of the lesion.

DESIGN

Imaging of both achilles tendons with ultrasonography and MRI was performed prior to unilateral surgery. Operative findings and histological biopsies together served as a reference.

PATIENTS

Twenty-seven patients (22 men, 5 women; mean age 44 years; 21 athletes) suffering from chronic achilles tendinopathy participated in the study. Eighteen patients had unilateral and 9 had bilateral symptoms.

RESULTS AND CONCLUSIONS

Surgical findings included 4 partial ruptures, 21 degenerative lesions and 2 macroscopically normal cases. Microscopy revealed tendinosis (degeneration) in all tendon biopsies, including cases with a partial rupture, but only slight changes in the paratendinous tissues (paratenon). Ultrasonography was positive in 21 of 26 and MRI in 26 of 27 cases. Severe intratendinous abnormalities and a sagittal tendon diameter > 10 mm suggested a partial rupture. In tendons with a false negative result histopathological changes were mild and a tendency towards a better clinical outcome was noted in the sonographic cases. Assessment of the paratenon was unreliable with both methods. Ultrasonography and MRI give similar information and may have their greatest potential as prognostic instruments.

Brånemark Novum: a new treatment concept for rehabilitation of the edentulous mandible. Preliminary results from a prospective clinical follow-up study

BACKGROUND

Brånemark fixtures were originally prescribed to be placed in two surgical stages. During the past years, reports on the placement of machined titanium implants in a one-stage procedure have been published, and the results have been encouraging. Recently there has been considerable interest in early or immediate loading.

PURPOSE

The purpose of this article is to report the preliminary clinical results of a new method for implant treatment of the edentulous mandible. The new protocol involves prefabricated components and surgical guides, elimination of the prosthetic impression procedure and attachment of the permanent fixed bridge on the day of implant placement.

METHODS

Fifty patients (26 males, 24 females) received 150 Brånemark Novum implants and were followed from 6 months to 3 years after implant placement. Bone width and height were determined preoperatively with the use of radiographs. The jaw was reduced in height to accommodate three special 5-mm wide implants. Precise implant positioning was accomplished with special drilling templates. Drill guides were placed over the drilling templates during site preparation using a series of specially designed drills. After the mucosa had been sutured back into position, a prefabricated titanium lower bar was connected with titanium screws to the transmucosal fixture. Another titanium bar was then attached by the prosthodontist, and a bite registration was performed. The bridge was attached to the upper bar. The permanent reconstruction was provided to the patient later the same day.

RESULTS

Three implants were lost to follow-up and three failed, resulting in an overall survival rate of 98%. One prosthesis failed, leaving a prosthetic survival rate of 98%. The average treatment time was approximately 7 hours. At the baseline examination, the marginal bone level was 0.72 mm below the reference point. The average marginal bone loss was 0.2 mm per year and 0.26 mm between the 3-month and 1-year control visits. The accumulated mean bone loss, including baseline, was -1.25 mm. A patient questionnaire demonstrated that 94% of the patients did not experience any discomfort during treatment and all patients would recommend the procedure to others.

CONCLUSION

The results of this study indicate that the precise surgical and prosthetic protocol allows successful prosthetic rehabilitation of mandibular edentulism and that the permanent reconstruction can be provided to the patient on the day of fixture surgery.

Phenotypic heterogeneity in motor neuron disease patients with CuZn-superoxide dismutase mutations in Scandinavia

Four-hundred and fifty-one blood samples from Scandinavian patients with motor neuron disease were analysed for mutations in the CuZn-superoxide dismutase gene. Forty-one (9.6%) of the 427 patients with the amyotrophic lateral sclerosis (ALS) form of the disease were found to have a disease-associated mutation, and 14 of these patients were apparently sporadic cases. A mutation was found in 12 of the 51 families with recognized familial ALS. The five different mutations found (Ala4Val, Val14Gly, Asp76Tyr, Asp90Ala, Gly127insTGGG) have different genetic characteristics and are associated with very variable phenotypes spanning from rapidly progressing disease with only lower motor neuron signs to very slowly progressing disease with both the upper and lower motor neuron systems affected. The patients showed different sites of onset, though the progressive bulbar palsy form of the disease appears to be rare among patients with a CuZn-superoxide dismutase mutation. The progression of motor signs and symptoms followed the same basic pattern in patients with different mutations. Extra-motor system symptoms were frequent among patients with a CuZn-superoxide dismutase mutation. The results suggest that patients with mutations in the CuZn-superoxide dismutase gene constitute one disease entity. The Val14Gly and Asp76Tyr mutations have not been reported before, and the latter is the first mutation to be found in exon 3 of the CuZn-superoxide dismutase gene.

Fruit and vegetable intake and type 2 diabetes: EPIC-InterAct prospective study and meta-analysis

Fruit and vegetable intake (FVI) may reduce the risk of type 2 diabetes (T2D), but the epidemiological evidence is inconclusive. The aim of this study is to examine the prospective association of FVI with T2D and conduct an updated meta-analysis. In the European Prospective Investigation into Cancer-InterAct (EPIC-InterAct) prospective case-cohort study nested within eight European countries, a representative sample of 16,154 participants and 12,403 incident cases of T2D were identified from 340,234 individuals with 3.99 million person-years of follow-up. For the meta-analysis we identified prospective studies on FVI and T2D risk by systematic searches of MEDLINE and EMBASE until April 2011. In EPIC-InterAct, estimated FVI by dietary questionnaires varied more than twofold between countries. In adjusted analyses the hazard ratio (95% confidence interval) comparing the highest with lowest quartile of reported intake was 0.90 (0.80-1.01) for FVI; 0.89 (0.76-1.04) for fruit and 0.94 (0.84-1.05) for vegetables. Among FV subtypes, only root vegetables were inversely associated with diabetes 0.87 (0.77-0.99). In meta-analysis using pooled data from five studies including EPIC-InterAct, comparing the highest with lowest category for FVI was associated with a lower relative risk of diabetes (0.93 (0.87-1.00)). Fruit or vegetables separately were not associated with diabetes. Among FV subtypes, only green leafy vegetable (GLV) intake (relative risk: 0.84 (0.74-0.94)) was inversely associated with diabetes. Subtypes of vegetables, such as root vegetables or GLVs may be beneficial for the prevention of diabetes, while total FVI may exert a weaker overall effect.

Long-term outcome of the Malmö preventive project: mortality and cardiovascular morbidity

OBJECTIVES

To analyse the effects on mortality and cardiovascular morbidity in a population-based sample, invited to an intervention programme incorporating a baseline screening examination and treatment programmes for subjects with cardiovascular risk factors, high alcohol intake and, in women, suspicion of breast cancer on mammography.

SETTING

Section of Preventive Medicine, Department of Medicine, University Hospital, Malmö, Sweden.

SUBJECTS

Birth cohorts (aged 32-51 years) invited to screening examination (men = 9. 923; women = 4.422) were compared to birth cohorts not invited (men = 6.655; women = 4.290). Mean participation rate in the invited cohorts was 71% (range 64-78%). SCREENING EXAMINATION: Between 1974 and 1992 a baseline screening including a physical examination, blood pressure, a questionnaire regarding, e.g. family history, lifestyle, and socio-economic factors, laboratory tests of serum cholesterol, triglycerides, gamma-glutamyl-transferase, blood glucose before and after an oral glucose load, as well as a mammography examination in women, was performed.

INTERVENTIONS

Subjects with hypertension; hyperlipidaemia; diabetes or glucose intolerance; high alcohol intake; or, in women, suspicion of breast cancer were referred to special outpatient clinics.

MAIN OUTCOME MEASURES

Total and cause-specific mortality, nonfatal myocardial infarction, and stroke, from the screening examination until the end of 1995, was followed in both the intervention and control groups, using national and/or local registries.

RESULTS

Total mortality did not differ significantly between the intervention group and control group. Cause-specific deaths were also similar except for 'other' deaths amongst men being significantly lower in the intervention group, mainly due to a lower mortality from 'other' causes (suicide, alcohol related deaths) in men under 40 years of age at baseline. Women under 40 years of age had a significantly lower mortality from cancer in the intervention group than in the control group. Nonfatal myocardial infarction and stroke did not differ between intervention and control group in either sex. Within the invited birth cohorts, nonparticipants had a higher total and cause-specific mortality.

CONCLUSIONS

Risk factor screening for major diseases such as cardiovascular disease, alcohol abuse, diabetes mellitus and breast cancer, and subsequent treatment of the detected risk factors/diseases - The Malmö Preventive Project - did not reduce total mortality in the intervention group as a whole. In subjects under 40 years of age at entry, total mortality was lower in the intervention group than in the control group. In men, this seemed to be due to a reduction of alcohol-related deaths, whilst in women death from cancer was reduced.

Consumption of sweet beverages and type 2 diabetes incidence in European adults: results from EPIC-InterAct

AIMS/HYPOTHESIS

Consumption of sugar-sweetened beverages has been shown, largely in American populations, to increase type 2 diabetes incidence. We aimed to evaluate the association of consumption of sweet beverages (juices and nectars, sugar-sweetened soft drinks and artificially sweetened soft drinks) with type 2 diabetes incidence in European adults.

METHODS

We established a case-cohort study including 12,403 incident type 2 diabetes cases and a stratified subcohort of 16,154 participants selected from eight European cohorts participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. After exclusions, the final sample size included 11,684 incident cases and a subcohort of 15,374 participants. Cox proportional hazards regression models (modified for the case-cohort design) and random-effects meta-analyses were used to estimate the association between sweet beverage consumption (obtained from validated dietary questionnaires) and type 2 diabetes incidence.

RESULTS

In adjusted models, one 336 g (12 oz) daily increment in sugar-sweetened and artificially sweetened soft drink consumption was associated with HRs for type 2 diabetes of 1.22 (95% CI 1.09, 1.38) and 1.52 (95% CI 1.26, 1.83), respectively. After further adjustment for energy intake and BMI, the association of sugar-sweetened soft drinks with type 2 diabetes persisted (HR 1.18, 95% CI 1.06, 1.32), but the association of artificially sweetened soft drinks became statistically not significant (HR 1.11, 95% CI 0.95, 1.31). Juice and nectar consumption was not associated with type 2 diabetes incidence.

CONCLUSIONS/INTERPRETATION

This study corroborates the association between increased incidence of type 2 diabetes and high consumption of sugar-sweetened soft drinks in European adults.

Autosomal recessive adult-onset amyotrophic lateral sclerosis associated with homozygosity for Asp90Ala CuZn-superoxide dismutase mutation. A clinical and genealogical study of 36 patients

We describe 36 patients (six were apparently sporadic cases and 30 were cases from nine families) with amyotrophic lateral sclerosis (ALS) characterized by a distinct phenotype associated with homozygosity for an Asp90Ala mutation in the CuZn-superoxide dismutase gene. The presenting motor manifestation in all patients was paresis in the legs, with slow progression to the upper extremities and finally to the bulbar muscles. The age of ALS onset varied from 20 to 94 years, with a mean of 44 years. Mean survival time was 13 years for the 11 deceased patients. However, this is probably biased and untypical (low) when compared with the disease duration in the surviving patients, and when considering other medical complications in the deceased patients. The rate of progression was highly variable, even within families. All patients showed signs of involvement of both upper and lower motor neurons. Other neurological features included painful muscle spasms and paraesthesiae in the lower extremities. Two-thirds of patients experienced difficulty with micturition. Electrophysiological studies confirmed the slow progression and spatial distribution of clinical symptoms in the peripheral motor system. Furthermore, [corrected] potentials evoked by transcranial magnetic stimulation (MEP) were compared with those evoked by cervical or lumbosacral electrical stimulation and often revealed marked slowing of transmission in central motor pathways. In Sweden and Finland ALS patients homozygous for the Asp90Ala mutation constitute a phenotypically characteristic subset of motor neuron disease.

Design and cohort description of the InterAct Project: an examination of the interaction of genetic and lifestyle factors on the incidence of type 2 diabetes in the EPIC Study

AIMS/HYPOTHESIS

Studying gene-lifestyle interaction may help to identify lifestyle factors that modify genetic susceptibility and uncover genetic loci exerting important subgroup effects. Adequately powered studies with prospective, unbiased, standardised assessment of key behavioural factors for gene-lifestyle studies are lacking. This case-cohort study aims to investigate how genetic and potentially modifiable lifestyle and behavioural factors, particularly diet and physical activity, interact in their influence on the risk of developing type 2 diabetes.

METHODS

Incident cases of type 2 diabetes occurring in European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts between 1991 and 2007 from eight of the ten EPIC countries were ascertained and verified. Prentice-weighted Cox regression and random-effects meta-analyses were used to investigate differences in diabetes incidence by age and sex.

RESULTS

A total of 12,403 verified incident cases of type 2 diabetes occurred during 3.99 million person-years of follow-up of 340,234 EPIC participants eligible for InterAct. We defined a centre-stratified subcohort of 16,154 individuals for comparative analyses. Individuals with incident diabetes who were randomly selected into the subcohort (n = 778) were included as cases in the analyses. All prevalent diabetes cases were excluded from the study. InterAct cases were followed-up for an average of 6.9 years; 49.7% were men. Mean baseline age and age at diagnosis were 55.6 and 62.5 years, mean BMI and waist circumference values were 29.4 kg/m(2) and 102.7 cm in men, and 30.1 kg/m(2) and 92.8 cm in women, respectively. Risk of type 2 diabetes increased linearly with age, with an overall HR of 1.56 (95% CI 1.48-1.64) for a 10 year age difference, adjusted for sex. A male excess in the risk of incident diabetes was consistently observed across all countries, with a pooled HR of 1.51 (95% CI 1.39-1.64), adjusted for age.

CONCLUSIONS/INTERPRETATION

InterAct is a large, well-powered, prospective study that will inform our understanding of the interplay between genes and lifestyle factors on the risk of type 2 diabetes development.

Insulin resistance in non-diabetic subjects is associated with increased incidence of myocardial infarction and death

AIMS

To compare the incidence of myocardial infarction and death in non-diabetic subjects with and without insulin resistance.

METHODS

Population-based prospective cohort study, in Malmö, Sweden, of 4748 non-diabetic subjects (60% women), aged 46-68 years, with no history of myocardial infarction or stroke. The prevalence of insulin resistance was established by the homeostasis model assessment (HOMA) and defined as values above the sex-specific 75th percentile (1.80 for women and 2.12 for men). Incidence of myocardial infarction and death is based on record linkage with local and national registers. Cox's proportional hazards model was used to assess the influence of insulin resistance after adjustment for age, sex, hyperglycaemia, raised arterial blood pressure, dyslipidaemia, central obesity, smoking and leisure-time physical activity.

RESULTS

Sixty-two subjects suffered a coronary event, and 93 subjects died during the 6-year follow-up period. Insulin resistance was after adjustment for other factors included in the insulin resistance syndrome and other potential confounders, associated with an increased incidence of coronary events (relative risk (RR) 2.18; 95% confidence interval (CI) 1.22-3.87; P = 0.008) and deaths (RR 1.62; 1.03-2.55; P = 0.038).

CONCLUSIONS

Insulin resistance, as assessed by the HOMA method, was in this cohort of middle-aged non-diabetic subjects associated with an increased incidence of myocardial infarction and death. This risk remained when smoking, low physical activity and factors included in the insulin resistance syndrome were taken into account in a stepwise regression model.

Volumetric and dosimetric evaluation of radiation treatment plans: radiation conformity index

PURPOSE

The use of conformal radiation therapy has grown substantially during the last years since three-dimensional (3D) treatment planning systems with beams-eye-view planning has become commercially available. We studied the degree of conformity reached in clinical routines for some common diagnoses treated at our department by calculating a radiation conformity index (RCI).

METHODS AND MATERIALS

The radiation conformity index, determined as the ratio between the target volume (PTV) and the irradiated volume, has been evaluated for 57 patients treated with 3D treatment plans.

RESULTS AND CONCLUSION

The RCI was found to vary from 0.3 to 0.6 (average 0.4), a surprisingly low figure. The higher RCI is typical for pelvic treatments (e.g., prostate) and stereotactic treatments. The lower RCI is found for extended tumors, such as mammary carcinomas where the adjacent nodes are included. The latter is also valid for most lung cancer patients studied. The RCI gives a consistent method for quantifying the degree of conformity based on isodose surfaces and volumes. Care during interpretation of RCI must always be taken, since small changes in the minimum dose can dramatically change the treated volume.

Real-time monitoring of DNA manipulations using biosensor technology

The potential of real-time biospecific interaction analysis technology for applications in molecular biology is described. DNA fragments are immobilized onto a biosensor surface using the high-affinity streptavidin-biotin system and subsequently used to monitor different unit operations in molecular biology, e.g., DNA strand separation, DNA hybridization kinetics, and enzymatic modifications. A model system comprising six oligonucleotides was used, which can be assembled into a 69-bp double-stranded DNA fragment. Using this system, the biosensor approach was employed to analyze multistep solid-phase gene assembly and the performance of different enzymes routinely used for the synthesis and manipulation of DNA. In addition, a concept for the determination of single-point mutations in DNA samples is described.

Blood conservation with tranexamic acid in total hip arthroplasty: a randomized, double-blind study in 40 primary operations

We performed a randomized, double-blind study on the effect of tranexamic acid on blood loss and blood transfusions in 40 primary total hip arthroplasties. Tranexamic acid, 10 mg/kg body weight, or placebo, was given intravenously just before the operation. Blood loss during the operation and postoperatively into the drains was recorded, as also were blood hemoglobin concentrations. Ultrasound examination 1 week postoperatively was done to estimate the blood loss due to remaining hematomas. Total (operation + drain) blood loss was 0.76 (95 CI 0.63-0.89) L in the tranexamic acid group as compared to 1.0 (CI 0.81-1.2) L in the placebo group (p = 0.03). The number of blood transfusions during the day of operation was 2 vs. 10 (p = 0.07) and the total number during the hospital stay was 5 vs. 13 (p = 0.2). 1 patient in each group had a pulmonary embolism.