Vascular surgical society of great britain and ireland: systemic effects of exercise in claudicants are associated with neutrophil activation

BACKGROUND: Claudication induces potentially harmful systemic effects which may be mediated through free radicals and neutrophil activation. This study examined the impact of these mechanisms on renal tubular function. METHODS: Flow cytometry was used to determine CD11b expression by neutrophils and monocytes, and expression of P selectin (CD62P) by platelets, in 16 patients with intermittent claudication and eight matched controls before and at intervals after exercise. Total antioxidant capacity (TAC) and von Willebrand factor (vWF) were measured at similar intervals. Renal tubular function was assessed before and 60 min after exercise by assay of retinol binding protein : creatinine ratio (RBP : Cr) in urine. All patients and none of the controls had a significant exercise-induced fall in ankle pressure. Fluorescein isothiocyanate-labelled monoclonal antibodies against CD11b and CD62P were added to blood and analysis was performed on the flow cytometer within 72 h. RESULTS: There were no significant differences in monocytes, platelets or vWF between patients and controls over time. There was a significant change in RBP : Cr following exercise in patients (median 4.2 (95 per cent confidence interval 2.4-85.2); P </= 0.01, Wilcoxon test) but not controls (2.7 (-1 to 7.5); P not significant). See Table above. CONCLUSION: Renal tubular function was adversely affected by acute exercise in claudicants. TAC was higher in claudicants at rest and was increased after exercise suggesting an increased free radical challenge. Neutrophil activation is significantly different between claudicants and controls before and after exercise, and may provide a link between free radical generation and renal tubular injury.

Vascular surgical society of great britain and ireland: angioplasty reverses the systemic effects of exercise in intermittent claudication

BACKGROUND: The choice between exercise training and percutaneous transluminal angioplasty (PTA) in the treatment of intermittent claudication (IC) remains controversial. Exercise is known to induce systemic effects in claudicants. This study aimed to determine whether such systemic effects are reversed by PTA. METHODS: Ten patients with IC were recruited before PTA. Having emptied the bladder and rested for 1 h, pre-exercise blood and urine samples were collected. Patients underwent treadmill exercise to their maximum walking time and further blood samples were collected at 10, 20 and 30 min. A second urine sample was collected at 60 min. Total antioxidant capacity (TAC) and von Willebrand factor (vWF) were measured in blood, and albumin : creatinine ratio (ACR) and retinol binding protein : creatinine ratio (RBP : Cr) in urine. Patients were recalled 2 weeks after successful angioplasty and the protocol was repeated. Statistical analysis was by Wilcoxon signed rank test. RESULTS: Following PTA, all patients walked for 5 min on the treadmill. All patients had a significant exercise-induced fall in ankle pressure that was reversed by PTA. Changes in TAC are shown in the Table. There was no significant change in vWF. Exercise in claudicants induced a significant increase in median ACR (pre/post exercise (pre-exercise value divided by post-exercise value) 0.8; P = 0.03) and in median RBP : Cr (pre/post exercise 1.8; P = 0.04). These changes were no longer evident after successful PTA. CONCLUSION: Exercise-induced changes in renal glomerular (ACR) and tubular function (RBP : Cr) in claudicants were reversed by successful angioplasty. PTA reduced the systemic TAC before and after exercise suggesting a reduced free radical challenge.

Vascular surgical society of great britain and ireland: patients with a failed infrainguinal bypass graft have abnormal lipid metabolism

BACKGROUND: Dyslipidaemias adversely affect vascular tone, endothelial function and platelet activation. Abnormal lipid metabolism has not been established as a risk factor for infrainguinal bypass graft failure. Lipid metabolism was evaluated prospectively in patients with patent and occluded grafts. METHODS: Twenty-eight patients with failed infrainguinal grafts (group 1) were identified from a prospective computerized database. Twenty matched controls with functioning grafts (group 2) were recruited from a graft surveillance programme. Fasting blood samples were analysed for triglyceride (TG), high-density lipoprotein (HDL) and cholesterol. A newly devised rapid TG tolerance test was conducted with analysis of TG at 1, 2 and 2.5 h. Endothelial lipoprotein lipase (LPL) was measured 30 min after intravenous administration of heparin 50 units kg-1. RESULTS: The cholesterol : HDL ratio was significantly higher in group 1 than group 2 (median 6.0 (range 3. 1-10.0) versus 4.7 (2.3-9.4); P = 0.0008, Mann-Whitney test) as was fasting TG (2.6 (1.0-6.3) versus 1.7 (0.6-4.7) mmol l-1; P = 0.03). The area under the curve of the TG tolerance test was not significantly different (P = 0.08); however, the 2.5-h levels of TG were significantly different between the groups (group 1, 2.0 (0.5-6. 6) mmol l-1; group 2, 1.2 (0.3-6.8) mmol l-1; P = 0.01). LPL was significantly lower in group 1 (52.4 (2.2-235.9) versus 86.8 (28. 6-281.5) mmol/l; P = 0.04). CONCLUSION: These data suggest that abnormal lipid metabolism is a significant risk factor for infrainguinal graft occlusion. This study provides a rationale for randomized trials of lipid-modifying therapies in patients undergoing arterial reconstruction for peripheral vascular disease.

Cognitive therapy for premenstrual syndrome: a controlled trial

The aim of this study was to evaluate the effectiveness of cognitive therapy (CT) as a psychological treatment for premenstrual syndrome (PMS), by comparison with a waitlist control group. Women meeting selection criteria for PMS were randomly allocated to one of two treatment groups: (i) an immediate treatment group, who received 12 weekly sessions of individual CT; or (ii) a waiting list group who recorded symptoms of PMS for a length of time equivalent to the duration of an individual treatment in the immediate treatment group. General practitioners and gynecologists referred women who were complaining of distressing and disabling emotional and physical symptoms in the second half of the menstrual cycle, as verified by 2 months of prospective diary recording. Assessments of the women's psychological and social functioning were made on entry to the study, 2 months later, and at the end of the treatment period. This design allows evaluation of the efficacy of CT relative to any spontaneous remission that may have occurred as a consequence of the passage of time, the keeping of menstrual diaries, interview, and self-rated assessments. Results indicated that CT was significantly more effective than assignment to the waitlist group. Diary measures and self-report questionnaires indicated an almost complete remission of psychological and somatic symptoms and of impairment of functioning. It is concluded that CT for PMS is associated with substantial improvements that cannot be attributed to the passage of time or the completion of the diary and other assessments.

Stable albinism induced without mutagenesis: a model for ribosome-free plastid inheritance

Maternally inherited chlorophyll deficiency, or albinism, is a standard marker in plant cytoplasmic genetics. Its stability is consistent with mutations in the plastid genome. Nuclear mutations inducing plastid ribosome deficiency (PRD) also lead to maternally inherited chlorophyll deficiency. Here we report that stable chlorophyll deficiency can be efficiently generated in cruciferous plants without mutagenesis by a short exposure to spectinomycin, an inhibitor of plastid protein synthesis. We show that the chlorophyll-deficient phenotype results from a deficiency in plastid ribosomes and plastid translation products. Loss of plastid ribosomes is irreversible. The data suggest that mutations are not essential for generating inheritable PRD. It allows the formulation of a more general model in which stable PRD can be induced by a variety of factors that prevent the formation of functional plastid ribosomes. A non-mutational mechanisms for generating inheritable chlorophyll deficiency has implications for the origin and inheritance of green-white variegation in nature.

Presence: creating order out of chaos

Surgery can be experienced as a time that throws the many dimensions of a person into a state of chaos. This article provides insight to the responses to chaos and describes ways in which to offer the quality of Presence as the essence of holistic care.

Ethanol, stroke, brain damage, and excitotoxicity

The N-methyl-d-aspartate (NMDA)-glutamate receptor could contribute to stroke, trauma, and alcohol-induced brain damage through activation of nitric oxide formation and excitotoxicity. In rat primary cortical cultures NMDA was more potent at activating nitric oxide formation than triggering excitotoxicity. Ethanol dose dependently inhibited both responses. In contrast, treatment of neuronal cultures with ethanol (100 mM) for 4 days significantly increased NMDA stimulated nitric oxide formation and excitotoxicity. These findings suggest that ethanol acutely inhibits but chronically causes supersensitivity to NMDA-induced excitotoxicity in neuronal cultures. To investigate ethanol's interaction with stroke induced damage models of global cerebral ischemia were studied. Transient global ischemia resulted in a loss of hippocampal CA1 pyramidal neurons over a 3- to 5-day period. Determinations of the NMDA receptor ligand binding stoichiometry or postischemic receptor binding changes did not show differences between neurons that undergo delayed neuronal death following ischemia and those that show no toxicity, for example, CA1 and dentate gyrus, respectively. Acute ethanol (3 g/kg) was found to protect against ischemia-induced CA1 hippocampal damage by lowering body temperature, but not under temperature controled conditions. These studies indicate that the factors contributing to stroke-induced brain damage are complex, although they are consistent with chronic ethanol increasing stroke-induced brain damage by increasing NMDA excitotoxicity.

The psychological effects of laparoscopy on women with chronic pelvic pain

BACKGROUND

Many women who undergo diagnostic laparoscopy for chronic pelvic pain do not have pelvic pathology. This has led to an interest in psychological factors that might contribute to their experience of pain. This study was designed to evaluate the effects of diagnostic laparoscopy on women with chronic pelvic pain and to explore possible psychological mechanisms.

METHODS

Seventy-one women undergoing laparoscopy for chronic pelvic pain were randomly allocated to one of two groups waiting different lengths of time for laparoscopy. Women were interviewed before laparoscopy and were followed up 1 week, 3 months and 6 months afterwards. Pain was assessed with an interview measure, diaries and visual analogue scales.

RESULTS

Pain reductions were observed from before to after diagnostic laparoscopy. Regression analysis was used to identify factors which predicted improvements in pain. The hypothesis that psychological factors would predict improvements in pain was confirmed. Pain improvements after laparoscopy were predicted by beliefs about pain and the change in each woman's evaluation of the seriousness of her condition. Other than baseline pain, these psychological variables were the only ones to emerge as predictors of pain change despite exploratory analysis of over 40 other variables.

CONCLUSIONS

Diagnostic laparoscopy can have beneficial effects in women with chronic pelvic pain. These effects appear to be the result of psychological mechanisms. Further investigation of these mechanisms could help in the understanding and treatment of women with chronic pelvic pain.

Hyperhomocysteinaemia is a risk factor for vein graft stenosis

OBJECTIVES

Many infrainguinal vein graft failures are due to progressive vein graft stenosis (VGS) from intimal hyperplasia. Systemic factors have been implicated in the aetiology of intimal hyperplasia. Hyperhomocysteinaemia (HHCA) is established as an independent risk factor for coronary and peripheral arterial disease. The objective of this study was to examine the influence of HHCA and other serological factors upon the development of VGS.

STUDY DESIGN

Thirty-eight patients who had undergone infrainguinal vein bypass were recruited to a case/control study from a graft surveillance program. Nineteen patients with documented VGS were matched against controls without stenosis for age, sex, length of time from surgery, diabetes, smoking history and preoperative symptom score. All patients were recalled for Duplex ultrasound scans, venesection and carbon monoxide estimation which were performed in a blinded fashion.

RESULTS

Statistical analysis of all parameters revealed that plasma homocysteine was significantly elevated in patients with VGS (p < 0.3, Wilcoxon rank sum).

CONCLUSIONS

These results suggest that HHCA is a previously unidentified risk factor for VGS. Patients with HHCA are susceptible to VGS and preoperative investigation would allow identification of patients at risk.

Homocysteine: an independent risk factor for the failure of vascular intervention

Hyperhomocysteinaemia is an independent risk factor for the early development of arterial disease. Homocysteine and cardiovascular risk factors were assessed in 41 young and 25 older patients with vascular disease. As homocysteine may act by the generation of free radicals, total antioxidant capacity was measured. Hyperhomocysteinaemia was found in 29 per cent of patients but there was no difference between young and older patients. Homocysteine level was unrelated to other cardiovascular risk factors. Young age, diabetes and hyperhomocysteinaemia were independent risk factors for the failure of vascular procedures (P = 0.006). Patients with hyperhomocysteinaemia had raised total antioxidant capacity. The potential of identifying and treating a subgroup of patients with a poor prognosis deserves further study.

Isolation of a Chlamydomonas reinhardtii telomere by functional complementation in yeast

We attempted to determine whether Chlamydomonas reinhardtii telomeres, which do not form G-quartet structures readily in vitro, are able to nucleate telomere addition in Saccharomyces cerevisiae. Restricted C. reinhardtii genomic DNA was ligated to a linear S. cerevisiae vector lacking a telomere. A C. reinhardtii telomere ligated to this unprotected end allowed vector replication as a linear DNA molecule in S. cerevisiae. DNA sequencing revealed common [T4AG3]n and variant T6AG3 and T5AG3 C. reinhardtii telomere repeats capped by S. cerevisiae telomere repeat units. The recognition of a C. reinhardtii telomere by the telomere maintenance machinery of S. cerevisiae is consistent with a common theme for telomere structure in organisms with divergent telomere repeats.

A transposon-like sequence with short terminal inverted repeats in the nuclear genome of Chlamydomonas reinhardtii

A 1.2 kb DNA sequence, flanked by a potential seven base target-site duplication, was found inserted into a TOC1 transposable element from Chlamydomonas reinhardtii. The insertion sequence, named TOC2, is a member of a family of repeated DNA sequences that is present in all the C. reinhardtii strains tested. It resembles class II transposable elements: it possesses short 14 bp imperfect terminal repeats that begin AGGAGGGT, and sub-terminal direct repeats located within 250 bp of the termini. No large open reading frames were found. The terminal bases and length of target-site duplication are important in classifying transposable elements. On this basis TOC2 does not fall readily into existing families of class II transposable elements found in plants.

Frontal lobe neglect in monkeys

Using a crossed-response task, monkeys with neglect induced by frontal lesions appear to have motor rather than sensory neglect. However, the crossed-response task may not reveal sensory neglect (inattention) if no perceptual discrimination is required. We therefore trained two monkeys in a perceptually complex crossed-response task. Following unilateral frontal (arcuate gyrus) ablation, we found no contralateral perceptual disorders or sensory neglect in either monkey but did find a failure to respond with the contralateral arm (motor neglect) in both monkeys. We also found that the monkeys made more incorrect responses with the arm ipsilateral to the lesion than they did with the contralateral arm. The errors made by the ipsilateral arm could be a compensatory strategy or a disinhibition phenomenon. Because these incorrect responses were not rewarded and became more frequent as motor neglect improved, the incorrect responses of the ipsilateral arm are not a compensatory strategy, but rather a defect we term "disinhibition hyperkinesia" or "allokinesia."