The effects of sodium bicarbonate ingestion on swimming interval performance in trained competitive swimmers.

The use of sodium bicarbonate (NaHCO3) supplementation to improve repeated high-intensity performance is recommended; however, most swimming performance studies examine time trial efforts rather than repeated swims with interspersed recovery that are more indicative of training sessions. The aim of this study, therefore, was to investigate the effects of 0.3 g.kg-1 BM NaHCO3 supplementation on sprint interval swimming (8 × 50 m) in regionally trained swimmers. Fourteen regionally competitive male swimmers (body mass (BM): 73 ± 8 kg) volunteered for this double-blind, randomised, crossover designed study. Each participant was asked to swim 8 × 50 m (front crawl) at a maximum intensity from a diving block, interspersed with 50 m active recovery swimming. After one familiarisation trial, this was repeated on two separate occasions whereby participants ingested either 0.3 g.kg-1 BM NaHCO3 or 0.05 g.kg-1 BM sodium chloride (placebo) in solution 60 min prior to exercise. Whilst there were no differences in time to complete between sprints 1-4 (p > 0.05), improvements were observed in sprint 5 (p = 0.011; ES = 0.26), 6 (p = 0.014; ES = 0.39), 7 (p = 0.005; ES = 0.60), and 8 (p = 0.004; ES = 0.79). Following NaHCO3 supplementation, pH was greater at 60 min (p < 0.001; ES = 3.09), whilst HCO3- was greater at 60 min (p < 0.001; ES = 3.23) and post-exercise (p = 0.016; ES = 0.53) compared to placebo. These findings suggest NaHCO3 supplementation can improve the latter stages of sprint interval swimming performance, which is likely due to the augmentation of pH and HCO3- prior to exercise and the subsequent increase in buffering capacity during exercise.

Meta-analysis of prognostic factors for patients with colorectal peritoneal metastasis undergoing cytoreductive surgery and heated intraperitoneal chemotherapy.

Background: Up to 15 per cent of colorectal cancers present with peritoneal metastases (CPM). Cytoreductive surgery and heated intraperitoneal chemotherapy (CRS + HIPEC) aims to achieve macroscopic tumour resection combined with HIPEC to destroy microscopic disease. CRS + HIPEC is a major operation with significant morbidity and effects on quality of life (QoL). Improving patient selection is crucial to maximize patient outcomes while minimizing morbidity and mortality. The aim of this study was to identify prognostic factors for patients with CPM undergoing CRS + HIPEC. Methods: A systematic search of MEDLINE, Embase and Cochrane Library electronic databases was performed using terms for colorectal cancer, peritoneal metastasis and CRS + HIPEC. Included studies focused on the impact of prognostic factors on overall survival following CRS + HIPEC in patients with CPM. Results: Twenty-four studies described 3128 patients. Obstruction or perforation of the primary tumour (hazard ratio (HR) 2·91, 95 per cent c.i. 1·5 to 5·65), extent of peritoneal metastasis as described by the Peritoneal Carcinomatosis Index (PCI) (per increase of 1 PCI point: HR 1·07, 1·02 to 1·12) and the completeness of cytoreduction (CC score above zero: HR 1·75, 1·18 to 2·59) were associated with reduced overall survival after CRS + HIPEC. Conclusion: Primary tumour obstruction or perforation, PCI score and CC score are valuable prognostic factors in the selection of patients with CPM for CRS + HIPEC.

Cooling strategies improve intermittent sprint performance in the heat of athletes with tetraplegia.

BACKGROUND: Precooling has been shown to enhance performance in repeated sprint exercise in able-bodied subjects in a hot environment. Spinal cord injury causes thermoregulatory impairment with a detrimental effect on performance. This study assessed whether cooling strategies before and during exercise in the heat enhances sprint performance in athletes with tetraplegia. METHODS: Eight male athletes with tetraplegia performed intermittent arm crank exercise in the heat (32.0 degrees C (0.1 degrees C); humidity, 50% (0.1%)) for a maximum of 60 min or until exhaustion. Trials involved a no-cooling control (CON), precooling (PRE) or cooling during exercise (DUR). Each intermittent sprint protocol consisted of varied periods of passive rest, maximal sprinting and active recovery. RESULTS: Both PRE and DUR cooling strategies improved the ability of the athletes to repeatedly perform high-intensity sprints, with times to exhaustion (TTE), whereas during the CON trial, athletes demonstrated a reduction in the total number of sprints and TTE (47.2 (10.8), 52.8 (5.8) and 36.2 (9.6) min for CON, PRE and DUR, respectively). Core temperature was significantly higher for CON (37.3 degrees C (0.3 degrees C)) when compared with both PRE and DUR (36.5 degrees C (0.6 degrees C) and 37.0 degrees C (0.5 degrees C), respectively, p<0.01). Ratings of perceived exertion and thermal sensation upon exhaustion or completion were not different. CONCLUSIONS: Athletes with tetraplegia should use a precooling or during-exercise cooling strategy specific to the characteristics of their sport when exercising in hot conditions.

Predictors of the use of complementary and alternative medicine (CAM) by women at high risk for breast cancer.

BACKGROUND: Few data exist regarding the use of complementary and alternative medicine (CAM) by unaffected women at high risk of breast cancer. METHODS: Self-reported CAM use by women from multiple-case breast cancer families was obtained by questionnaire. Factors associated with CAM use were assessed using multiple logistic regression. RESULTS: Of 892 women, 55% (n=489) used CAM, 6% (n=53) specifically to prevent cancer. CAM use was independently associated with tertiary education level (OR 2.56, 95% CI 1.83-3.58, p<0.001), greater physical activity (OR 1.05 per hour of physical activity/week, 95% CI 1.00-1.10, p=0.049), greater anxiety (OR 1.92, 95% CI 1.16-3.16, p=0.01), not currently smoking (OR 0.64, 95% CI 0.42-0.97, p=0.037) and lower perceived BC risk (OR 0.82 per 20 percentage points, 95% CI 0.72-0.94, p=0.005). CONCLUSIONS: The majority of high-risk women use CAM, but mostly for reasons other than cancer prevention. Most predictors of CAM use are consistent with the limited literature for women at high risk for cancer.

Extended formulary nurse prescribing--another saliva substitute roadblock.

United Kingdom family physicians, General Practitioners (GPs), are allowed to prescribe from a Department of Health-approved list of non-medicines (the 'ACBS' list) which includes a majority of proprietary saliva substitutes. Independent nurse prescribing, introduced in 2001, has improved patient access to effective remedies for a wide range of common medical problems. Further qualified 'extended formulary nurse prescribers' have access to a limited range of prescription medicines, and all non-prescription medicines that GPs may currently prescribe. Despite their specified role in the management of oral complications encountered in palliative care, a similar anomaly in NHS rules that prevents dental practitioners from prescribing ACBS listed saliva substitutes also prevents nurses from prescribing them. Sadly, patients are suffering poorer access to simple and effective remedies to conditions such as xerostomia - a condition that has recognised impact on their quality of life.

Use of videotape to assess mobility in a controlled randomized crossover trial of physiotherapy in chronic multiple sclerosis.

OBJECTIVES: To determine to what degree assessment of mobility based on comparison of videotape recordings before and after courses of physiotherapy in patients with chronic multiple sclerosis (MS) is reliable, correlates with 'live' assessments and indicates benefit. DESIGN: Prospective data collection within a randomized crossover controlled trial of physiotherapy at home, as an outpatient, or 'no therapy' in 40 patients. SETTING: Hospital outpatients: outpatient and home physiotherapy. OUTCOMES: Mobility change based on a comparison of short video recordings before and after each treatment period was scored independently by two physiotherapists blinded to therapy type and other measures of outcome. Scores were compared with changes in the Rivermead Mobility Index (RMI) and other indices assessed by a physiotherapist in the patient's home. RESULTS: The two video observers agreed substantially on patient outcome. Changes in walking based on video correlated with RMI for home treatment (r = 0.41, p = 0.008) but not for hospital or no treatment periods (r = 0.14 and 0.15): video changes correlated with the 'live' assessor's global change score inconsistently ('no therapy' r = 0.48, p = 0.002, hospital r = 0.30, p = 0.06 and home r = 0.17, p = 0.30 treatment periods). Based on video data alone, improved mobility was evident following home therapy for only one observer but not for the other or the averaged scores of both. CONCLUSION: There was substantial agreement between two observers deciding on change in mobility based on independent blinded evaluation of short video sequences. However the correlations of these with 'live' assessments were variable. Physiotherapy had a less clear benefit on mobility based on video analysis alone compared with 'live' assessments. The study highlights the need for more objective measures of habitual mobility over longer periods.

Cost-effectiveness of fluticasone propionate administered via metered-dose inhaler plus babyhaler spacer in the treatment of asthma in preschool-aged children.

STUDY OBJECTIVES: To evaluate the cost-effectiveness of inhaled fluticasone propionate (FP) in children aged 12 to 47 months with asthma symptoms. DESIGN: A retrospective economic analysis conducted from the perspective of the Danish health-care system, based on clinical data from a 12-week study. SETTING: Thirty-three outpatient centers in nine countries. PATIENTS: Two hundred thirty-seven children aged 12 to 47 months with documented history of recurrent wheeze or asthma symptoms. INTERVENTIONS: Two dosages of FP, 100 microg/d and 200 microg/d, and placebo administered in two divided doses via a metered-dose inhaler and a Babyhaler (Glaxo Wellcome; Middlesex, UK) spacer device. MEASUREMENTS: Effectiveness in terms of asthma exacerbations, control of cough and wheeze symptoms, symptom-free days, overall direct costs of asthma management in Danish kroner at 1999 prices, and mean and incremental cost-effectiveness ratios. RESULTS: FP, 200 microg/d, was significantly more effective than placebo treatment in terms of the proportion of exacerbation-free patients (73.7% vs 59.8%; p = 0.025) and patients experiencing a > or = 25% improvement in cough symptoms (57.9% vs 39.0%; p = 0.018). The costs per exacerbation-free patient, per patient with a > or = 25% improvement in cough and wheeze symptoms from baseline, and per symptom-free day were lower in the FP groups than in the placebo group. The incremental cost-effectiveness ratios for these end points indicated that the additional benefits of FP, 200 microg/d, were achieved at a lower overall cost compared with placebo treatment. CONCLUSIONS: From the perspective of the Danish health-care system, FP, 100 microg bid, administered via the Babyhaler inhalation device was cost-effective relative to standard therapy with bronchodilators alone.

Evaluation of glucose monitoring devices in the hyperbaric chamber.

Diabetic patients may experience fluctuations in whole blood glucose (WBG) levels while receiving hyperbaric oxygen therapy (HBO) resulting in seizure-like activity. Therefore, hyperbaric medical attendants must accurately monitor the WBG levels of these patients during HBO. In addressing this concern, this study evaluated the accuracy and reliability of commercially available glucometers (Glucometer M+, Companion 2, HemoCue, One Touch II, and ExacTech Pen) in the hyperbaric environment. WBG samples were prepared, ranging from 25 to 250 mg/dl, for testing glucometers at ground level and at 2.36 atmospheres absolute (ATA). It was noted that at 2.36 ATA, glucose values increased using the Glucometer M+, but decreased with the Companion 2 and HemoCue. The One Touch II values decreased in the hyperglycemic ranges (> 150 mg/dl), whereas the ExacTech Pen monitor readings increased in the hypoglycemic ranges (< 100 mg/dl). The accuracy of WBG monitors is significantly affected by changes in atmospheric pressure.

Hypothalamic tissue stimulates hippocampal pyramidal neuron survival during development: evidence from intraocular double transplants.

The present study was undertaken to evaluate innervation and possible growth promotion by posterior hypothalamic tissue on different areas that are, or are not, interactive with this brain region during development. Posterolateral hypothalamus was dissected from embryonic day 17 rat fetuses, and inserted into the anterior chamber of the eye of adult rat hosts. Two weeks postgrafting, a second transplant consisting of either fetal hippocampal, cerebellar, or lung tissue was placed adjacent to the first graft. Growth of the intraocular double transplants was monitored weekly by measurements through the cornea. Fetal hippocampal tissue grew significantly larger when placed together with a hypothalamic graft, as compared to single hippocampal transplants. Cerebellar or lung tissue growth was not stimulated by a hypothalamic cograft. Pyramidal neuron cell counts demonstrated a significantly higher final number of these neurons in growth-stimulated hippocampal grafts, as compared to non-stimulated single hippocampal grafts. Immunohistochemistry with antibodies directed against histamine or histidine decarboxylase revealed that hippocampal transplants received the most dense histaminergic innervation. Cerebellar transplants contained occasional histaminergic neurites, and lung tissue never exhibited any histaminergic innervation from the adjacent hypothalamic graft. Taken together, these results demonstrate a growth-promoting effect of posterior hypothalamic tissue on developing hippocampal tissue, as well as target specificity of histaminergic innervation patterns.

Neuroprotectants in Honghua: glucose attenuates retinal ischemic damage.

PURPOSE: This study examined the neuroprotective properties of Honghua, an extract of safflower used as an herbal medicine in China, in several experimental models of retinal ischemia. METHODS: Honghua and other agents were tested (1) in the ex vivo chick embryo retina assay (CER) for anti-excitotoxin efficacy and against simulated ischemia (30 min glucose/oxygen deprivation); and (2) in the in vivo adult rat retina dye-photothrombosis assay. Active components of Honghua were purified by conventional chromatographic techniques. RESULTS: In the CER, Honghua protected against excitotoxicity of glutamate, N-methyl-D-aspartate, kainate, and quisqualate, and against neuronal degeneration caused by simulated ischemia. Honghua more potently protected against simulated ischemia than against the agonists. In the in vivo adult rat retina, ischemic damage was reduced greatly by intravitreal injection of Honghua. An approximately 100-fold purification of an active principle was achieved chromatographically. The purest fractions were rich in glucose, so the effects of glucose in the ischemia models were determined. Many neuroprotective effects of Honghua were mimicked by pure solutions of equivalent glucose concentration. Glucose (> 3.2 mmol/l) in the CER-ischemia assay provided protection. Glucose did not protect against the lesions induced by direct application of the excitotoxic agonists. Intravitreal injection of glucose provided highly significant neuroprotection in the adult rat retina dye-photothrombosis model. CONCLUSIONS: These results suggest that retinal excitotoxic damage in vivo can occur secondary to depletion of cellular energy reserves, and therefore may be prevented by simple procedures that maintain the availability of energy sources.

Multipartite nature of potato virus X.

Potato virus X (PVX) was among the first viruses to be purified. Nonetheless, properties of the purified virus remain contentious. The literature has been heavily influenced by the concept of a virus as a monopartite entity. Despite the fact that electron micrographs invariably show large proportions of shorter virus particles, the latter are universally ignored. Seven distinct classes of particle lengths were detected. Seven RNA species of approximate sizes 6.4, 3.6, 3.0, 2.1, 1.8, 1.4, and 0.9 kb were extracted from these purified virus preparations. This study shows clearly that shorter PVX particles are not breakage products and indicates that they may reflect fundamental properties of the genome strategy. Furthermore, other potexviruses have been found to contain many shorter particles, and the level of these particles is stable during purification. PVX is generally believed to consist of particles of single length even though the literature does not confirm this conclusion. The notion of a single particle length appears to reflect historical concepts of what a virus should be rather than what PVX is. This report considers whether shorter rods present in virus preparations of PVX are distinctive products of infection. The problem addressed is significant because if affects conclusions concerning the mechanisms of PVX biosynthesis and replication.

Ecological effects of short-term ciprofloxacin treatment of travellers' diarrhoea.

Forty-two subjects travelling to Mexico for 11 days were enrolled in a randomized, double-blind, placebo-controlled trial comparing ciprofloxacin 250 mg twice daily for three days or placebo for treatment of travellers' diarrhoea. Seventeen (41%) subjects were randomized to treatment. By the last treatment day, all seven evaluable subjects in the ciprofloxacin group, and three of eight evaluable subjects in the placebo group were cured (P = 0.04). The mean time to cure was 26 h for ciprofloxacin and 60 h for placebo-treated patients (P = 0.03). Faecal specimen were collected pre-travel, after four days in Mexico, 48 h post-travel and four weeks post-travel. Potentially pathogenic Escherichia coli strains carrying diarrhoeagenic virulence genes were detected by DNA hybridization tests, during or after travel, in 41% of treated and 31% of asymptomatic travellers. Travel, irrespective of diarrhoea and type of treatment, had a minor impact on the aerobic and anaerobic microflora. In travellers with ongoing diarrhoea, a suppression of the numbers of anaerobic bacteria was found, but the microflora was otherwise virtually unaffected. Significantly increased frequencies of E. coli resistant to ampicillin, doxycycline, chloramphenicol and co-trimoxazole were found during and after travel in all categories of travellers, though more frequently in subjects who experienced diarrhoea. The susceptibility of Bacteroides spp. remained unchanged. The sensitivity of E. coli to ciprofloxacin was not affected by travel, except in four ciprofloxacin-treated subjects who acquired multiresistant E. coli with ciprofloxacin MICs of > or = 0.125 mg/L post-travel. Bacteroides strains with MICs of > or = 64 mg/L were isolated post-travel from four ciprofloxacin-treated patients, and from one of the other 34 travellers not treated with ciprofloxacin.

Examination of potato virus X proteins synthesized in infected tobacco plants.

Nucleotide sequence analysis of potato virus X (PVX) genomic RNA predicts five open reading frames (ORFs). Previous analysis of total RNAs from PVX-infected leaf tissue suggested that six subgenomic RNAs are synthesized during infection. However, the proteins encoded by the genomic RNA, the subgenomic RNAs, or the predicted ORFs have not been identified in vivo. To characterize the coding properties of the viral RNA, particularly to determine whether the five predicted ORFs function in vivo, total protein extracts prepared from PVX-infected leaf tissue were analyzed by using antibodies raised against virus-specific synthetic peptides and against the virus capsid protein. Dot blot analyses showed that these antibodies reacted to PVX-infected extracts, indicating in vivo expression of the five predicted ORFs. In addition, Western blot (immunoblot) analysis of the extracts showed that ORF 1, 2, 3, and 4 peptide antisera and coat protein antiserum detect predominantly a single protein.

Can psychotherapy help patients with psoriasis?

Two groups of people with psoriasis attended a short series of meetings conducted by a clinical psychologist. During these sessions the patients were given the opportunity to discuss between themselves problems created by their skin complaint and they were taught specific relaxation techniques for use whenever they felt under stress. Psychological tests showed that the participants were a noticeably anxious group compared to the general population. However, their levels of anxiety were significantly reduced by the end of the study. There was also a modest trend towards physical improvement. No such changes were seen in a matched control group.

Irreversible opiate agonists and antagonists: V. Hydrazone and acylhydrazone derivatives of naltrexone.

We have synthesized a series of hydrazones and acylhydrazones of naltrexone. These substitutions had modest effects on competition of mu binding but many greatly enhanced the relative potency of the compounds for delta receptors. Increased delta affinity was most prominent with the acylhydrazones. Many of the derivatives elicited a wash-resistant inhibition of binding which was restricted to mu, not delta, binding sites. This wash-resistant inhibition of binding did not correlate with affinity, as determined by IC50 values, implying that the inhibition could not be explained simply by slow rate of dissociation due to increased affinity.

Early changes in plasma and urinary potassium in diuretic-treated patients with systemic hypertension.

Two groups of patients with uncomplicated systemic hypertension were studied. Group 1 included 11 patients who had overt hypokalemia with diuretic drug treatment, and group 2 included 11 patients who remained normokalemic. After baseline studies without treatment were performed, both groups received hydrochlorothiazide, 50 mg twice daily. Plasma potassium (PK) was significantly reduced within the first day of treatment and stabilized by day 7 in both groups. The average decrease in PK was 1.0 +/- 0.1 mEq/liter (p less than 0.01) in the first group and 0.6 +/- 0.2 mEq/liter (p less than 0.01) in the second group. Cumulative losses of K were approximately 200 mEq in the hypokalemic group and were minimal in the normokalemic group as assessed by 24-hour urinary collections. Patients in the hypokalemic group also had a greater reduction in body weight and blood pressure. Supplementation with KCl, 96 mEq/day, or triamterene, 200 mg/day, in 9 hypokalemic patients resulted in an increase of PK to approximately 3.5 mEq/liter leveling off by day 7, and a cumulative K retention of approximately 200 mEq. Thus, overt thiazide-induced hypokalemia was associated with small and biologically unimportant losses of K from body stores. With replacement therapy the estimated amount of retained K was also small.

Uptake of exogenous aspartate into circumventricular organs but not other regions of adult mouse brain.

Adult mice were treated intraperitoneally with aspartate (Asp) at one of several doses (0.47-3.75 mmol/kg) and 30 min later given a subcutaneous Asp injection at the same dose. This treatment regimen resulted in steady state blood Asp elevations, a given dose producing the same degree of elevation at both 30 and 60 min. The lowest and highest doses, respectively, produced four-fold and 55-fold elevations of serum Asp. In selected circumventricular organ (CVO) regions of brain which lack blood brain barriers, tissue Asp levels rose 1.5 and 3 times above control values following the lowest and highest doses, respectively, whereas tissue Asp remained unchanged in non-CVO brain regions. Thus, even very moderate Asp dosing causes marked increases in CVO Asp. In order to analyze the pattern of Asp uptake into CVO, Asp was assayed in numerous subdivisions of each CVO, and maps were constructed which reflected microregional concentration differences. The pattern of Asp distribution suggests that Asp enters brain via fenestrated capillaries serving certain portions of CVO and then spreads into adjacent brain tissue. In separate experiments, we administered a single high dose of Asp (15 mmol/kg) to both adult and infant mice and measured Asp in serum and select brain regions 60 min later. Asp concentrations in serum and CVO (but not other brain regions) rose markedly at both ages but the increases were greater in serum and therefore also in CVO of infants.(ABSTRACT TRUNCATED AT 250 WORDS)