Oxygen free radicals and contrast nephropathy

Ionic, high-osmolality contrast medium causes nephrotoxicity associated with increased intrarenal adenosine production. To test the hypothesis that oxygen free radicals (produced during intrarenal adenosine catabolism to xanthine) should be implicated in the pathogenesis of ionic, high-osmolality contrast medium nephrotoxicity in humans and to determine whether magnesium protects the kidney from oxygen free radical injury following contrast, 39 patients with mild renal dysfunction were divided into low (LoMg++) and normal (NlMg++) magnesium states and randomized to precoronary angiography oral allopurinol (a xanthine oxidase inhibitor) or placebo. Creatinine clearance and urinary xanthine excretion were measured before and after angiography. Forty-eight hours after contrast medium exposure, placebo-treated LoMg++ and NlMg++ patients had 61%+/-5% and 67%+/-6% increases in urinary xanthine excretion, respectively; however, placebo-treated LoMg++ patients had a greater (79%+/-9% v 35%+/-6%; P < 0.01) decrease in creatinine clearance than placebo-treated NlMg++ patients. Allopurinol-treated LoMg++ and NlMg++ patients had no significant change in urinary xanthine excretion, but did have 40%+/-7% and 33%+/-5% decreases, respectively, in creatinine clearance 48 hours after contrast medium exposure. There was no difference in renal dysfunctional response among placebo-treated NlMg++ patients or allopurinol-treated LoMg++ or NlMg++ patients. These data suggest (1) that oxygen free radicals contribute to ionic, high-osmolality contrast medium nephrotoxicity in hypomagnesemic patients with mild renal disease and (2) that magnesium attenuates the nephrotoxicity mediated by oxygen free radicals.

Alexithymia: relationship with ego defense and coping styles

There is controversy in the literature as to whether alexithymia reflects a deficit in the cognitive processing of emotions or a defensive coping style. Previous studies with clinical populations reported a strong association between alexithymia and a maladaptive (immature) ego defense style. The present study was designed to examine this relationship in nonclinical populations, and also to explore the relationships between alexithymia and three general styles for coping with stressful situations. Sample 1, 287 nonclinical adults, completed the Twenty-Item Toronto Alexithymia Scale (TAS-20) and the Defense Style Questionnaire (DSQ). Sample 2, 83 undergraduate students who had been categorized previously into alexithymic and nonalexithymic subgroups, completed the DSQ and the Coping Inventory for Stressful Situations (CISS). In sample 1, the TAS-20 and its three factors were associated most strongly with an immature defense style, weakly with a neurotic defense style, and negatively with a mature defense style. In sample 2, alexithymic students scored significantly higher than nonalexithymic students on the immature and neurotic defense factors of the DSQ and significantly lower on the mature defense factor. Alexithymic students also scored significantly higher on the emotion-oriented coping scale and the distraction component of the avoidance-oriented coping scale of the CISS and significantly lower on the task-oriented coping scale. The results fail to support the view that alexithymia is an adaptive defense or coping style.

Ultraviolet light in the orthopaedic operating theatre

This article looks at the physical aspects of Ultraviolet C light and the practical aspects encountered when setting up a UVC system in Winford Orthopaedic Hospital, Bristol for the purposes of a clinical trial to study the effect of UVC on bacterial load in the theatre air and in the wounds of patients undergoing total joint replacement. The results of that clinical trial will then be described followed by an outline of the problems encountered with using UVC.

Relationships between alexithymia and psychological characteristics associated with eating disorders

This study examines the relationships between alexithymia and psychological characteristics and behaviors that are commonly associated with eating disorders. The 20-item Toronto Alexithymia Scale (TAS-20) and the Eating Disorder Inventory (EDI) were administered to a group of 48 female patients with anorexia nervosa, a matched comparison group of 30 normal women, and an unmatched comparison group of 116 male and 118 female university students. In the anorexic and male student groups, the TAS-20 correlated significantly and positively with the EDI subscales, Ineffectiveness, Interpersonal Distrust, Interoceptive Awareness, and Maturity Fears. The TAS-20 correlated significantly only with Interpersonal Distrust in the matched comparison group, and only with Ineffectiveness and Interpersonal Distrust in the female student group. The results suggest that alexithymia is related to several psychological traits that are characteristic of patients with eating disorders and thought to play a role in the development of the disorders but is unrelated to attitudes and behaviors concerning abnormal eating and body weight and shape.

A longitudinal study of alexithymia and psychological distress in inflammatory bowel disease

A group of 104 patients with inflammatory bowel disease (IBD) was followed longitudinally for 6 months. While anxiety and depression scores were influenced over time by changes in the level of disease activity, there was no significant change in alexithymia scores. The findings support the contention that alexithymia is a stable personality characteristic in some IBD patients, in contrast to anxiety and depression which are state phenomena influenced by the level of disease activity.

Optimisation of ultraclean air. The role of instrument preparation

The use of ultraclean air (UCA) in operating theatres reduces the infection rate after joint replacement but some cases of infection still occur. We investigated one possible source of contamination, namely the setting up of instruments in a conventional plenum-ventilated preparation room. We measured bacterial fallout using agar settle plates and compared instruments set up in the preparation room with those set up in the UCA theatre, assessed the effect of covering instruments after preparation and compared fallout during their preparation with total fallout throughout the operation. Our findings showed that covering the instruments reduced total bacterial fallout fourfold by reducing the exposure time, particularly during periods of increased activity and bacterial dispersal. Preparation in the UCA theatre and subsequent covering of the instruments reduced total fallout 28-fold. All measurable bacterial fallout occurred during the setting up and not during surgery.

Cross-cultural alexithymia: development and validation of a Hindi translation of the 20-Item Toronto Alexithymia Scale

The possibility that alexithymia may be a culture-bound construct was evaluated by developing a Hindi version of the Twenty-Item Toronto Alexithymia Scale and assessing its psychometric properties in a sample of 285 normal young adults in India. The Hindi version of the scale (TAS-20-H) showed excellent cross-language equivalence with the English version. In addition, the TAS-20-H demonstrated adequate internal consistency, good test-retest reliability, and a three-factor structure consistent with the three-factor model of the original scale.

Incidence of five common fracture types in an institutional epileptic population

We have reviewed 4521 patient-years and analysed 185,066 seizures to calculate the incidence of five common fractures in an epileptic population. Only 25.0 per cent of these fractures were known to have occurred during a seizure. When age and sex matched against a 'normal population', there was an increased incidence of femoral neck fractures (5.2 x), inter-trochanteric fractures (9.9 x), ankle fractures (9.9 x) and proximal humerus fractures (4.2 x). Surprisingly, there was no increased incidence of wrist fractures. Overall, there was a 4.3 x increased risk for all fractures and 3.2 x increased risk of fractures not related to fits. There was no evidence for the first fracture occurring at a younger age in this population. The possible causes of this greatly increased risk are discussed.

Air contamination during skin preparation and draping in joint replacement surgery

Despite the use of ultraclean air, there are still cases of infection in total joint arthroplasty. One possible route by which bacteria may enter the wound is indirectly by contamination of instruments during skin preparation and draping. We found that bacterial air counts were 4.4 times higher during preparation and draping for hip or knee arthroplasty using an unscrubbed, ungowned leg holder than during the operation itself. With the leg holder scrubbed and gowned during preparation and draping, the air counts were reduced but were still 2.4 fold greater than intraoperatively. On some occasions, the air counts during preparation and draping exceeded the standards for ultraclean air irrespective of the attire of the leg holder. We recommend that the leg is held by a scrubbed and gowned member of the team. More importantly, we consider that instrument packs should be opened only after skin preparation and draping have been completed.

Alexithymia in essential hypertensive and psychiatric outpatients: a comparative study

The purported association between alexithymia and essential hypertension was investigated in a sample of 114 hypertensive patients using the well-validated twenty-item Toronto Alexithymia Scale. Alexithymia was also assessed in a group of 113 general psychiatric outpatients and in a group of 130 normal adults. A rate of 55.3% of alexithymia was found in the hypertensive group compared with significantly lower rates of 32.7% in the psychiatric group and 16.3% in the normal controls. The results support the view that a high prevalence of alexithymia may be found among patients with disorders that were categorized in the past as "classical" psychosomatic diseases. It is hypothesized that a deficit in the cognitive processing and modulation of emotions may leave alexithymic individuals prone to states of heightened sympathetic arousal that are conducive to the development of essential hypertension.

Glycosaminoglycan specificity of a heparin-binding peptide

Glycosaminoglycans are complex sulfated polysaccharides with a diverse range of biological functions. Three glycosaminoglycan standards--chondroitin sulfate, dermatan sulfate and heparin--were characterized during this study. The interaction of the heparin binding site of protein C inhibitor, represented by the peptide sequence 264-283, in solution with the above glycosaminoglycan standards was studied. Circular dichroism spectroscopy was used to determine the dominant secondary structure induced in the peptide upon binding the relevant glycosaminoglycans. The various glycosaminoglycans induced different secondary structures. The level of induced secondary structure by dermatan sulfate and heparin was approximately twice that induced by chondroitin sulfate. For chondroitin sulfate and heparin, alpha-helix was the dominant ordered secondary structure, whereas for dermatan sulfate the beta-strand conformation dominated. The order of secondary structure induction of the protein C inhibitor peptide by the glycosaminoglycans paralleled the reported biological activities of these glycosaminoglycans for mediation of the biological activity in the intact protein. The strength of the interaction of dermatan sulfate and heparin with the protein C inhibitor peptide was measured by determining the concentration of salt required to inhibit 50% of the interaction. The values determined were 0.1 and 0.3 M salt for dermatan sulfate and heparin, respectively. These results show that different glycosaminoglycans can support different secondary structures in the protein C inhibitor peptide.

Wound disinfection with ultraviolet radiation

Bacteria were counted concurrently in the air and wounds during the first 20 min of total joint arthroplasty procedures in two theatres: a conventional plenum ventilated theatre with ultraviolet C (UVC) tubes installed and a filtered vertical laminar flow theatre. Four theatre environments were tested: conventional theatre and clothing; conventional theatre with UVC protective clothing, with UVC set to produce 100 or 300 microW cm-2 s-1 irradiation; and filtered vertical laminar flow air with staff wearing cuffed cotton/polyester clothing. When used, the UVC was activated 10 min after starting an operation to assess the effect of UVC clothing alone, and of UVC radiation on bacteria already present in the wound. Compared with conventional theatres, UVC clothing reduced air counts by 38%, UVC at 100 microW cm-2 s-1 by 81%, at 300 microW cm-2 s-1 by 91%, and laminar flow by 92%. Wounds counts fell correspondingly by 66% with UVC clothing, 87% with UVC at 100 microW cm-2 s-1 and 92% both with UVC at 300 microW cm-2 s-1 and laminar flow. In conventional and laminar flow theatres air and wound counts correlated closely but in UVC theatres wound counts were lower than levels expected from prevailing air counts suggesting that UVC kills bacteria in wounds as well as in air.

Abundance and Distribution of Iron on the Moon

The abundance and distribution of iron on the moon is derived from a near-global data set from Clementine. The determined iron content of the lunar highlands crust ( approximately 3 percent iron by weight) supports the hypothesis that much of the lunar crust was derived from a magma ocean. The iron content of lower crustal material exposed by the South Pole-Aitken impact basin on the lunar farside is higher ( approximately 7 to 8 percent by weight) and consistent with a basaltic composition. This composition supports earlier evidence that the lunar crust becomes more mafic with depth. The data also suggest that the bulk composition of the moon differs from that of the Earth's mantle. This difference excludes models for lunar origin that require the Earth and moon to have the same compositions, such as fission and coaccretion, and favors giant impact and capture.

Nephrotoxicity from contrast media: attenuation with theophylline

PURPOSE

To determine if depression of creatinine clearance after administration of contrast medium may be prevented with theophylline.

MATERIALS AND METHODS

A nonionic, low-osmolality contrast medium (iopamidol) or an ionic, high-osmolality contrast medium (sodium diatrizoate) was administered to 93 patients. Before the examination, these patients were given theophylline or a placebo orally. There were also 30 patients who received an adenosine-uptake inhibitor (dipyridamole). Creatinine clearance and urinary adenosine levels were measured before and after angiography.

RESULTS

Creatinine clearance decreased 18% +/- 4 in the placebo-iopamidol group but did not decrease in the theophylline group; urinary adenosine increased 67% +/- 7. Creatinine clearance decreased 42% +/- 5 in the placebo-sodium diatrizoate group and decreased 24% +/- 3 in the theophylline group; urinary adenosine increased 119% +/- 8. In the dipyridamole group in which iopamidol was given, urinary adenosine increased 96% +/- 7 and creatinine clearance decreased 37% +/- 5.

CONCLUSION

Intrarenal adenosine can be implicated in the pathogenesis of hypertonic contrast medium nephrotoxicity.

Alexithymia in inflammatory bowel disease. A case-control study

The purported association between alexithymia and inflammatory bowel disease (IBD) was investigated in a group of 112 IBD patients (89 with ulcerative colitis and 23 with Crohn's disease) using the well-validated 20-Item Toronto Alexithymia Scale. Alexithymia was assessed also in a group of 112 normal subjects matched for gender, age, and education. The IBD group was significantly more alexithymic than the control group, and no significant difference was found between the ulcerative colitis and Crohn's disease patients. Alexithymia was unrelated to the duration of illness and the level of disease activity. Although the rate of alexithymia in the IBD group (35.7%) was significantly higher than the rate in the control group (4.5%), it is lower than rates of alexithymia that have been found among psychiatric patients with disorders that also have been linked theoretically and clinically with alexithymia.

The twenty-item Toronto Alexithymia Scale--I. Item selection and cross-validation of the factor structure

Addressing shortcomings of the self-report Toronto Alexithymia Scale (TAS), two studies were conducted to reconstruct the item domain of the scale. The first study resulted in the development of a new twenty-item version of the scale--the TAS-20. The TAS-20 demonstrated good internal consistency and test-retest reliability, and a three-factor structure theoretically congruent with the alexithymia construct. The stability and replicability of this three-factor structure were demonstrated in the second study with both clinical and nonclinical populations by the use of confirmatory factor analysis.

The Twenty-item Toronto Alexithymia Scale--II. Convergent, discriminant, and concurrent validity

A previous paper described the development of the twenty-item Toronto Alexithymia Scale (TAS-20) and reported preliminary evidence of reliability and factorial validity of the scale. This paper describes a study that further evaluated the construct validity of the TAS-20 by examining its relationship with measures of personality traits theoretically related or unrelated to the alexithymia construct, as well as its relationship with an observer-rated measure of alexithymia. Evidence of convergent and discriminant validity of the TAS-20 was demonstrated in samples of university students by a pattern of correlations with the scales of the NEO Personality Inventory and separate measures of psychological mindedness and need-for-cognition that was consistent with theoretical predictions. The concurrent validity of the scale was demonstrated by positive correlations with observer-ratings of alexithymia in a sample of behavioural medicine out-patients.

A difference between front-loaded streptokinase and standard-dose recombinant tissue-type plasminogen activator in preserving left ventricular function after acute myocardial infarction (the Central Illinois Thrombolytic Therapy Study)

A blinded, randomized trial compared the effects of front-loaded streptokinase with those of the conventional dose of intravenous recombinant tissue-type plasminogen activator (rt-PA) on left ventricular (LV) function after acute myocardial infarction (AMI). Thrombolytic therapy was administered in the emergency departments of 30 community hospitals in central Illinois, and subsequent studies were performed at 1 tertiary referral center. Patients aged < or = 75 years with a first AMI who could be treated within 4 hours of the onset of chest pain were randomly assigned to receive either streptokinase (375,000 IU bolus, followed by 1,125,000 IU over 1 hour) or rt-PA (10 mg bolus, followed by 50 mg in the first hour, and 20 mg/hour for the next 2 hours). All patients were treated with aspirin (325 mg) and intravenous heparin. Patients were transferred for angiography within 24 hours. During the 30-month study, 253 patients were treated with intravenous thrombolytic therapy 2.4 +/- 1.0 hour after the onset of AMI. In patients with anterior wall AMI (n = 90), global LV ejection fraction measured by angiography within 24 hours was 45 +/- 12% with rt-PA, and 39 +/- 13% with streptokinase (p < 0.03). Convalescent radionuclide angiography documented a persistent beneficial effect of rt-PA on LV regional wall contractility, but not global ejection fraction. There were no differences between rt-PA and streptokinase in preserving global or regional LV function in patients with inferior wall AMI.

Effect of antiseptics, ultraviolet light and lavage on airborne bacteria in a model wound

We modelled a 'clean' surgical wound lightly contaminated with airborne bacteria, using agar, ovine muscle and ovine adipose tissue. This was used to assess the effect on bacteria of ultraviolet C light (UVC) 1200 mu W/cm2, hydrogen peroxide 3%, povidone-iodine 1% and 10%, chlorhexidine 0.05%, pulsed jet lavage with UVC and syringe and needle lavage with chlorhexidine 0.05%. All the agents were effective on agar, but mixing with blood or plasma neutralised hydrogen peroxide and povidone-iodine 1%. All the agents were less effective on tissue specimens than on agar, but were more effective on adipose tissue than on muscle. All the antiseptics except chlorhexidine were less effective when blood or plasma was added to muscle specimens before disinfection. UVC after pulsed jet lavage had an additive effect. Syringe and needle lavage with chlorhexidine 0.05% was the most effective method tested; it reduced colony counts by 99.8% and warrants clinical investigation.