Predictors of increased PaCO2 during immersed prone exercise at 4.7 ATA

During diving, arterial Pco(2) (Pa(CO(2))) levels can increase and contribute to psychomotor impairment and unconsciousness. This study was designed to investigate the effects of the hypercapnic ventilatory response (HCVR), exercise, inspired Po(2), and externally applied transrespiratory pressure (P(tr)) on Pa(CO(2)) during immersed prone exercise in subjects breathing oxygen-nitrogen mixes at 4.7 ATA. Twenty-five subjects were studied at rest and during 6 min of exercise while dry and submersed at 1 ATA and during exercise submersed at 4.7 ATA. At 4.7 ATA, subsets of the 25 subjects (9-10 for each condition) exercised as P(tr) was varied between +10, 0, and -10 cmH(2)O; breathing gas Po(2) was 0.7, 1.0, and 1.3 ATA; and inspiratory and expiratory breathing resistances were varied using 14.9-, 11.6-, and 10.2-mm-diameter-aperture disks. During exercise, Pa(CO(2)) (Torr) increased from 31.5 +/- 4.1 (mean +/- SD for all subjects) dry to 34.2 +/- 4.8 (P = 0.02) submersed, to 46.1 +/- 5.9 (P < 0.001) at 4.7 ATA during air breathing and to 49.9 +/- 5.4 (P < 0.001 vs. 1 ATA) during breathing with high external resistance. There was no significant effect of inspired Po(2) or P(tr) on Pa(CO(2)) or minute ventilation (Ve). Ve (l/min) decreased from 89.2 +/- 22.9 dry to 76.3 +/- 20.5 (P = 0.02) submersed, to 61.6 +/- 13.9 (P < 0.001) at 4.7 ATA during air breathing and to 49.2 +/- 7.3 (P < 0.001) during breathing with resistance. We conclude that the major contributors to increased Pa(CO(2)) during exercise at 4.7 ATA are increased depth and external respiratory resistance. HCVR and maximal O(2) consumption were also weakly predictive. The effects of P(tr), inspired Po(2), and O(2) consumption during short-term exercise were not significant.

Evidence for adaptive plasticity in elderly monaural hearing aid users

Hearing aids can induce perceptual changes in some elderly listeners but few studies have investigated physiological changes in this population. Loudness discomfort levels and acoustic reflex thresholds were measured in long-term users of a single hearing aid. The results show an asymmetry of +2 to +9 dB between ears in the sound level that (i) causes loudness discomfort and (ii) elicits a reflex contraction of the middle ear muscles. The elevation of the acoustic reflex threshold occurs in the ear with hearing aid experience, irrespective of the ear of stimulation. Therefore, there is evidence of adaptive plasticity and this can be measured at the level of the auditory brainstem.

A 5-year audit of haemodialysis access

This is a review of our experience with vascular access procedures over a 5-year period at Derriford Hospital, Plymouth, UK. The aims of the study were to examine the outcome of vascular access procedures and factors influencing access survival. Between April 1995 and March 2000, 151 patients who underwent 221 vascular access procedures were studied. Of these, 136 had autogenous arteriovenous fistulae, whereas 85 had prosthetic AV grafts (41% in the thigh). The overall primary failure rate was 21% whereas the 1- and 5-year cumulative access survival rates were 60 and 41%, respectively. Thigh grafts have a mean survival of 36 months compared with 32 months for prosthetic upper limb and 43 months for autogenous fistulae. Age, diabetes and predialysis status did not significantly influence access survival. Thrombosis was responsible for access failure in 62 cases (28%). Avoiding subclavian vein canulation and performing vessel mapping prior to access placement should reduce the risk of access failure due to outflow obstruction.

Placental folate transport and binding are not impaired in pregnancies complicated by fetal growth restriction

Maternal folate deficiency is associated with fetal growth restriction, however, transfer of folate across placentae of pregnancies complicated by fetal growth restriction has never been investigated. We studied whether maternal to fetal 5-methyltetrahydrofolate (5MTF) transport in the ex vivo dually perfused isolated cotyledon, binding of [(3)H] folate (PteGlu) to the syncytial microvillous membrane, and protein expression of folate receptor alpha (FR-alpha) and reduced folate carrier (RFC) in these placentae are disturbed. Placental clearance of 5MTF from the maternal perfusate appeared to be non-saturable over a range of 50 to 500 nm, independent of albumin and flow-independent. No statistically significant differences between placentae complicated with fetal growth restriction and uncomplicated pregnancies were observed. Binding characteristics of [(3)H-]PteGlu to microvillous membranes of fetal growth restriction versus control placentae were similar: B(max)of 3.9+/-2.0 (mean+/-s.d.) versus 4.0+/-1.6 pmol/mg protein and a K(d)of 0.037+/-0.010 versus 0.040+/-0.018 nm. Expression of FR-alpha and RFC were not different in placentae of both groups studied. In conclusion, fetal growth restriction appears not to be associated with impaired maternal to fetal placental folate transport, placental receptor binding, or expression of FR-alpha and RFC.

Cofactor-dependent enzyme catalysis in functionalized ionic solvents

Functionalized, hydrogen-bonding ionic liquids have been successfully evaluated as media for the performance of cofactor-dependent enzyme catalysed oxidations; the effects of incorporating hydroxyl groups into both the cation and anion have been studied and the dependence of activity upon water content has been evaluated.

Randomized prospective study comparing pre-emptive epidural and intraoperative perineural analgesia for the prevention of postoperative stump and phantom limb pain following major amputation

Background

The reported incidence of phantom limb pain (PLP) following amputation is up to 85 per cent. This study was designed to compare the efficacy of two perioperative analgesic techniques with respect to postoperative stump pain (POSP) and PLP.

Methods

Patients were randomized prospectively. Group 1 received a pre-emptive epidural for a minimum of 24 h before surgery which was continued after operation. Group 2 had intraoperative placement of a perineural catheter for the administration of local anaesthetic by infusion after operation. All amputations were performed under general anaesthesia. POSP was assessed by visual analogue score (VAS), ranging from 0 to 10. The presence of PLP was assessed 6 and 12 months after operation.

Results

A total of 30 patients were recruited, 12 men and 18 women, of median age 74 (range 47–93) years. Each group was well matched for concurrent cardiovascular disease and the level of amputation. VAS at 6 h, 1, 2 and 3 days after operation was significantly less in group 1 than group 2 (P &lt; 0·05, two-sample t test). Six patients died in each group and one was lost to follow-up. The overall incidence of PLP was 75 per cent at 6 months and 44 per cent at 12 months, with no significant difference between the two groups.

Conclusion

In this series, pre-emptive epidural analgesia significantly reduced the severity of POSP. The incidence of PLP remains disappointingly high regardless of the analgesic technique used.

Changes in ventilatory threshold with exercise training in a sedentary population: the HERITAGE Family Study

The purpose of this study was to evaluate the effect of exercise training intensity relative to the ventilatory threshold (VT) on changes in work (watts) and VO2 at the ventilatory threshold and at maximal exercise in previously sedentary participants in the HERITAGE Family Study. We hypothesized that those who exercised below their VT would improve less in VO2 at the ventilatory threshold (VO2vt) and VO2max than those who trained at an intensity greater than their VT. Supervised cycle ergometer training was performed at the 4 participating clinical centers, 3 times a week for 20 weeks. Exercise training progressed from the HR corresponding to 55% VO2max for 30 minutes to the HR associated with 75% VO2max for 50 minutes for the final 6 weeks. VT was determined at baseline and after exercise training using standardized methods. 432 sedentary white and black men (n = 224) and women (n = 208), aged 17 to 65 years, were retrospectively divided into groups based on whether exercise training was initiated below, at, or above VT.

RESULTS

1) Training intensity (relative to VT) accounting for about 26% of the improvement in VO2vt (R2 = 0.26, p < 0.0001). 2) The absolute intensity of training in watts (W) accounted for approximately 56% of the training effect at VT (R2 = 0.56, p < 0.0001) with post-training watts at VT (VT(watts)) being not significantly different than W during training (p > 0.70). 3) Training intensity (relative to VT) had no effect on DeltaVO2max. These data clearly show that as a result of aerobic training both the VO2 and W associated with VT respond and become similar to the absolute intensity of sustained (3 x /week for 50 min) aerobic exercise training. Higher intensities of exercise, relative to VT, result in larger gains in VO2vt but not in VO2max.

Validity and reliability of combining three methods to determine ventilatory threshold

PURPOSE

This research was undertaken to validate a combination of methodologies to determine ventilatory threshold (VT).

METHODS

Three methods were used individually and then combined to determine VT as follows: 1) ventilatory equivalencies, 2) excess CO2 production, and 3) a modified V-slope method. Three groups of participants-endurance athletes (N = 132), healthy, aerobically active adults (N = 31), and healthy, sedentary/low-active adults (N = 22)-were independently evaluated for VT and compared with the criterion standard lactate threshold (LT) defined as the first rise in blood lactate with increasing intensity of exercise.

RESULTS

VT and LT were significantly correlated using the combined VT method within each study group (r = 0.98, 0.97, and 0.95, respectively; P < 0.001). Mean VO2 values at VT and LT were not significantly different between the three groups (P > 0.20). The combined method improved the determination rate of VT and reduced the standard deviation of the LT - VT difference by 80-170% over the individual methods. During test-retest procedures VO2lt and VO2vt determined by the combined method met criteria demonstrating further reliability.

CONCLUSION

The combined method to determine VT is valid and reliable across a wide fitness range in healthy individuals and improves the determination rate and accuracy of VT determination over the use of single methods.

Acute effect of exercise on blood glucose and insulin levels in women with gestational diabetes

OBJECTIVE

To evaluate the effect of a single session of exercise (cycling), at rest (control condition) and at two intensity levels (low- and moderate-intensity exercise conditions), on blood glucose and insulin in pregnancy complicated by gestational diabetes mellitus (GDM).

METHODS

A one-group repeated measures design was used. Women aged 18-38 with GDM, no other complications, not on insulin, and not exercising regularly were recruited. The women rested or exercised at the two intensities for 30 min and rested for 2 h after each session. Blood was sampled for blood glucose, insulin and hematocrit at baseline and every 15 min.

RESULTS

There was no difference at baseline in blood glucose levels. The blood glucose level was significantly lower for each exercise condition compared to rest, and for moderate compared to low-intensity exercise (5.2 vs. 4.3 vs 3.9 mmol/l) at the end of exercise (30 min), and for the two exercise conditions compared to rest at 15 min after exercise (4.9 vs 4.4 vs. 4.0 mmol/l). By 45 min after exercise, the blood glucose values were nearly identical. The area under the curve for blood glucose was significantly lower for low- and moderate-intensity exercise than for rest (p = 0.01). The slope of change in insulin among the three conditions, from baseline to the 30-min session, approached significance (p = 0.065). The power for that analysis was 0.51. A sample of 23 would have been required to increase the power to 0.80.

CONCLUSIONS

Significant declines in blood glucose level were observed during low- and moderate-intensity exercise compared to rest. These differences were gone by 45 min after exercise. Continued research should examine those with high body mass index and more pronounced hyperglycemia for further evaluation of the effect of exercise on blood glucose and insulin levels in women with GDM.

Diacylglycerol kinase theta is translocated and phosphoinositide 3-kinase-dependently activated by noradrenaline but not angiotensin II in intact small arteries

Diacylglycerol (DG) kinase (DGK) phosphorylates the lipid second messenger DG to phosphatidic acid. We reported previously that noradrenaline (NA), but not angiotensin II (AII), increases membrane-associated DGK activity in rat small arteries [Ohanian and Heagerty (1994) Biochem. J. 300, 51-56]. Here, we have identified this DGK activity as DGKtheta, present in both smooth muscle and endothelial cells of these small vessels. Subcellular fractionation of artery homogenates revealed that DGKtheta was present in nuclear, plasma membrane (and/or Golgi) and cytosolic fractions. Upon NA stimulation, DGKtheta translocated towards the membrane and cytosol (155 and 153% increases relative to the control, respectively) at 30 s, followed by a return to near-basal levels at 5 min; AII was without effect. Translocation to the membrane was to both Triton-soluble and -insoluble fractions. NA, but not AII, transiently increased DGKtheta activity in immunoprecipitates (126% at 60 s). Membrane translocation and DGKtheta activation were regulated differently: NA-induced DGKtheta activation, but not translocation, was dependent on transient activation of phosphoinositide 3-kinase (PI 3-K). In addition, DGK activity co-immunoprecipitated with protein kinase B, a downstream effector of PI 3-K, and was increased greatly by NA stimulation. The rapid and agonist-specific activation of DGKtheta suggests that this pathway may have a physiological role in vascular smooth-muscle responses.

Lichtenstein patch or Perfix plug-and-patch in inguinal hernia: a prospective double-blind randomized controlled trial of short-term outcome

BACKGROUND

Open mesh used in anterior inguinal hernia repair can be configured as a flat patch (Lichtenstein operation) or as a cone-shaped preformed plug and supplementary patch (plug-and-patch operation; Perfix Plug; Davol Inc, Cranston, RI).

METHODS

One hundred forty-one patients were randomly allocated and blinded to receive either a Lichtenstein patch or a Perfix plug-and-patch. Information before the operation and on postoperative days 3 and 14 was recorded by an independent blinded observer to include operating time, postoperative pain, analgesic medication, return to activity and work, and quality of life assessment.

RESULTS

Operating time (32 vs 37.6 minutes) was significantly shorter in the plug-and-patch group (P = .01). During days 1 through 8, patients who had undergone the plug-and-patch operation experienced less pain, and their physical functioning on day 3 was significantly better (P = .013). Days of analgesic medication (4.0 vs 4.6 days), return to normal activity (2.8 vs 3.6 days), return to work (17.0 vs 20.8 days), and total days of work missed (14.3 vs 16.1 days) were similar in both groups (P = NS for all comparisons).

CONCLUSIONS

Compared with patients who received the Lichtenstein patch for ambulatory inguinal hernia repair, patients who underwent the Perfix plug-and-patch operation experienced less postoperative pain in the first 8 days after the operation but consumed similar postoperative analgesic medication. The rate of return to normal activity and work is similar in both groups, which indicates no superiority for the plug-and-patch operation in overall rehabilitation and societal costs. Overall hospital costs are greater for the plug-and-patch operation ($120 [US]) compared with the Lichtenstein patch ($20 [US]), with a negligible (5.6 minutes) saving of operating room time for the plug-and-patch operation.

Neuropsychological functioning of adults with attention deficit hyperactivity disorder

The neuropsychological functioning of adults with Attention Deficit Hyperactivity Disorder (ADHD) was compared to that of healthy controls and individuals with mild psychiatric disorders including attentional complaints. Thirty adults in each group were examined on the Conners' Continuous Performance Test (CPT) and measures of attention, executive function, psychomotor speed, and arithmetic skills. The ADHD group performed lower than healthy controls on most measures. However when compared to the psychiatric group, the performances of the ADHD group were not significantly lower on any of the measures. The predictive power of the tests was poor in discriminating ADHD from psychiatric disorder. Implications for the clinical diagnosis of ADHD are discussed.

Visualisation of biomedical datasets by use of growing cell structure networks: a novel diagnostic classification technique

BACKGROUND

Medical research produces large multivariable datasets that are difficult to visualise and interpret intuitively. We describe a novel growing cell structure (GCS) technique that compresses multidimensional datasets into two dimensional maps with colour overlays that can be visually interpreted.

METHODS

The two-dimensional map is self-discovered from the training set by distribution of cases to different nodes according to similarity between the cases at each node. Nodes are added to the map until there is no further significant reduction in error. The Parzen window method is used to estimate the probability distribution of the training cases, and this probability is converted to posterior class probabilities by use of Bayes' theorem. Classification performance can be assessed by means of receiver operating characteristic (ROC) curves. Colour maps of the values of each input variable at each node are constructed, which illustrate the relation between each input variable and the overall distribution of cases in the network map.

FINDINGS

From a dataset of 11 input variables from 692 fine-needle aspirate samples from breast lesions, a 32-node network produced an area under the ROC curve of 0.96, which was not significantly different from that for logistic regression (0.98, z=1.09, p>0.05). Colour maps of the input variables showed that some variables had discrete distributions over exclusively benign or malignant areas of the network, and were thus discriminant, whereas others, such as foamy macrophages, covered both benign and malignant regions.

INTERPRETATION

This technique produces dimensional compression that allows multidimensional data to be displayed as two-dimensional colour images. This envisioning of information allows the highly developed visuospatial abilities of human observers to perceive subtle inter-relations in the dataset.

Transgenic Arabidopsis leaf tissue expressing a modified oryzacystatin shows resistance to the field slug Deroceras reticulatum (Müller)

Transgenic Arabidopsis thaliana has been developed which expresses the oryzacystatin mutant OC-I delta 86, which is an inhibitor of the major proteinase present in the digestive gland of the slug, Deroceras reticulatum. When fed on leaf tissue from plants expressing this inhibitor the growth of juvenile slugs was significantly reduced by 31% compared with those feeding on control leaf tissue. Furthermore, while surviving slugs did not individually consume less when feeding on leaf tissue expressing OC-I delta 86, the total amount of leaf tissue eaten was 50% less, due to reduced survival of slugs. The synthetic cysteine proteinase inhibitors E-64 and leupeptin also significantly reduced slug weight gain (by at least 40%) and digestive gland cysteine proteinase activity when administered in an artificial diet, indicating that their antimetabolic effects are due to direct inhibition of gut proteolytic activity. These results suggest that transgenic crop plants expressing phytocystatins could be used to suppress the growth rates of slug populations in the field.

Ruptured abdominal aortic aneurysms: selecting patients for surgery

OBJECTIVES

Mortality from ruptured abdominal aortic aneurysm (RAAA) remains high. Despite this, withholding surgery on poor-prognosis patients with RAAA may create a difficult dilemma for the surgeon. Hardman et al. identified five independent, preoperative risk factors associated with mortality and proposed a model for preoperative patient selection. The aim of this study was to test the validity of the same model in an independent series of RAAA patients.

METHODS

A consecutive series of patients undergoing surgery for RAAA was analysed retrospectively by case-note review. Thirty-day operative mortality and the presence of the five risk factors: age (> 76 years), creatinine (Cr) (> 190 mumol/l), haemoglobin (Hb) (< 9 g/dl), loss of consciousness and electrocardiographic (ECG) evidence of ischaemia were recorded for each patient.

RESULTS

Complete data sets existed for 69 patients (mean age: 73 years, range: 38-86 years, male to female ratio: 6:1). Operative mortality was 43%. The cumulative effect of 0, 1 and 2 risk factors on mortality was 18%, 28% and 48%, respectively. All patients with three or more risk factors died (eight patients).

CONCLUSIONS

These results lend support to the validity of the model. The potential to avoid surgery in patients with little or no chance of survival would spare unnecessary suffering, reduce operative mortality and enhance use of scarce resources.

Exaggerated blood pressure response to exercise: importance of resting blood pressure

Normotensive individuals who exhibit an exaggerated blood pressure (BP) response to exercise have an increased risk of future hypertension. However, previous studies failed to control for resting BP despite the fact that an elevated resting BP in the normotensive range is also a strong predictor of future hypertension. Therefore, we determined whether maximal systolic BP is associated with resting BP. Resting BP was measured in 68 healthy normotensive men on three separate days. The subjects then performed a graded, maximal exercise test on a Monark cycle ergometer. Maximal systolic BP was strongly correlated with resting systolic BP (r = 0.64, P < 0.0001). Subjects with elevations in systolic BP during maximal exercise (> 220 mmHg) also had higher (P < 0.005) resting BP than those without (< 220 mmHg). When stepwise regression analyses were performed, systolic BP at rest was a significant independent predictor of maximal systolic BP, explaining over 40% of the variability. These results suggest that exaggerated BP response as a predictor of future hypertension reported in previous studies may be little more than a simple reflection of elevated resting BP. Specifically, these studies should not be interpreted as demonstrating that exercise BP is a better predictor of future hypertension than resting BP alone. In the future, defining the BP 'response' to exercise as a change score (i.e. maximal BP minus resting BP) may be advantageous as it permits the effects of exercise to be examined independently of the level of resting BP.

Energy deposition pattern from tritium and different energy photons--a comparative study

Energy deposition patterns of beta particles from tritium decay have been analyzed in comparison with photon radiation in the energy range from 12 to 1250 keV. Energy deposition was modeled by Monte Carlo means using electron tracks in water vapor with a complete follow up of delta electrons. Ionizations have been used as representative of track structure. Frequencies of clusters on a nanometer scale and their spatial distribution in spherical targets representing cell nuclei have been derived. Cluster analysis has been carried out by implementing a k-means method. Frequencies of ionization clusters from tritium are similar to 60-100 keV photons. Spatial distribution of clusters from tritium closely match approximately 70 keV photons up to 2 microm separation.

Cardiovascular and plasma catecholamine response to static exercise in normotensive blacks and whites

OBJECTIVES

The objectives of the present study were (1) to evaluate the pressor response to an isometric handgrip exercise in normotensive black and white males; (2) to measure plasma catecholamine levels pre- and post-exercise, as an index of sympathetic nervous system activity; and (3) to quantify the pressor response to bolus intravenous injections of phenylephrine (an alpha-specific agonist).

METHODS

Cardiovascular and catecholamine responses to an isometric handgrip exercise (3 minutes at 30% MVC) were measured in 15 normotensive blacks and whites. In another phase of the study, pressor responses to bolus injections of phenylephrine were assessed to evaluate alpha-adrenergic sensitivity.

RESULTS

The blood pressure in the blacks increased from 119/69 to 160/120 mm HG during isometric exercise, while in the whites it increased from 118/67 to 153/110 mm HG. The blacks exhibited a greater diastolic blood pressure reactivity, as evidenced by a significant race x time interaction (p < 0.05). The heart rate responses were not significantly different between the two groups. The plasma levels of norepinephrine were similar at rest, but were 25% lower in the blacks than in the whites following isometric exercise (p < 0.01). Black subjects also demonstrated an increased pressor response to intravenous injections of phenylephrine at rest (p < 0.05).

CONCLUSIONS

The enhanced vascular sensitivity to norepinephrine may have contributed to the greater exercise pressor response in the blacks.

Amount of care given and caregiving satisfaction: a latent growth curve analysis

We examined the wear-and-tear hypothesis using data from 4 annual interviews with 130 (128 White) middle-aged daughters caring for their physically impaired, elderly mothers. We formulated a latent growth curve model hypothesizing that increases in the amount of care given by daughters caused a decrease in caregiving satisfaction, independent of caregiving duration. We found considerable individual variability and change in both caregiving satisfaction and the amount of care given in univariate latent growth curve analyses. Contrary to the wear-and-tear hypothesis, a multivariate latent growth curve analysis revealed duration of caregiving had no effect on either initial caregiving satisfaction or change in satisfaction. An elaborated wear-and-tear model was supported, however. The mechanism for decline in satisfaction is an increase in the amount of care given.

Creating a high-performance team through proactive management

Numerous articles, business consultants, and scholars argue that high-performing management teams lead to higher productivity in organizations. Unfortunately, few managers are able to successfully develop such teams in their organizations. This article outlines the five strategies that define proactive management and produce high-performing teams.

Recurrent varicose veins: assessment of the saphenofemoral junction

Thirty-six consecutive unselected patients, who had apparently previously undergone saphenofemoral ligation for primary uncomplicated long saphenous varicosities and who had then re-presented with recurrent thigh varices emanating from the groin, underwent preoperative clinical assessment, hand-held Doppler and duplex ultrasonographic examination and varicography to establish the presence or absence of saphenofemoral incompetence as the cause of recurrence. All patients underwent reexploration of the saphenofemoral junction (SFJ) via a lateral approach. Twenty-six patients had an intact SFJ (type I recurrence) and ten had varices arising from either a thigh perforator, or from abdominal or perineal veins (type II recurrence). Clinical examination alone was poor at distinguishing type I from type II recurrence. Doppler ultrasonography was sensitive (88 per cent) but non-specific (40 per cent). In contrast, duplex scanning was insensitive (42 per cent) but extremely specific (100 per cent) and accurate, with a positive predictive value of 100 per cent. Varicography also had a specificity and positive predictive value of 100 per cent, a sensitivity of 73 per cent and in addition provided a precise anatomical 'road-map'. A combination of clinical examination and hand-held Doppler ultrasonography seems to be the most appropriate first-line method of preoperative assessment in these patients. Duplex ultrasonography, if available, will provide additional useful information about both the SFJ and the presence of thigh perforators. Contrast examination may be reserved for patients who have equivocal results on non-invasive investigations, who have had more than one previous groin operation or who have, in addition, deep venous disease.

Experimental experience with a temporary intraluminal heparin-bonded polyurethane arterial shunt

After vascular injury, intraluminal arterial shunting may be employed if definitive surgery must be delayed. This paper describes use of a heparin-bonded polyurethane shunt to restore distal circulation after ligation of the femoral artery in sheep. In studies to determine tissue viability for 12 h after insertion into the femoral artery, five of seven shunts remained patent. In another series of experiments to study tissue viability after limb ischaemia, the femoral artery was ligated and a tight Esmarch bandage applied to the limb for 6 h before shunt insertion. The shunt remained patent for 12 h in five of six cases. Nearly all shunt failures occurred shortly after placement and were attributable to intimal damage arising from difficulties during insertion.

Evaluation of the Colin STBP-680 at rest and during exercise: an automated blood pressure monitor using R-wave gating

The application of automated blood pressure measurement during exercise has been limited by inaccuracies introduced by the effects of accompanying motion and noise. We evaluated a newly developed automated blood pressure monitor for measuring exercise blood pressure (Colin STBP-680; Colin, San Antonio, Texas, USA). The STBP-680 uses acoustic transduction with the assistance of the electrocardiogram R-wave to trigger the sampling period for blood pressure measurement. The automated monitor readings were compared with simultaneous technician mercury sphygmomanometric readings in the same arm. Blood pressure was measured in 18 men at rest and during exercise at 40% VO2 peak, (low intensity), 70% VO2 peak (moderate intensity) and VO2 peak (high intensity) on the cycle ergometer. Mean(s.d.) systolic blood pressure difference between the automated monitor and mercury manometer readings at rest and during exercise at low, moderate and high work intensities were 3(0) mmHg, 3(2) mmHg, 1(1) mmHg, and 0(11) mmHg respectively (analysis of variance; P > 0.05). Resting diastolic blood pressure obtained with the STBP-680 was similar to the mercury manometer readings (78(10) versus 81(7) mmHg (P > 0.05). Exercise diastolic pressure at the low level of work intensity was almost identical between the automated monitor and mercury manometer readings (64(8) versus 65(10) mmHg (not significant)). Diastolic blood pressure readings between the STBP-680 and mercury manometer showed a greater difference at the moderate and high workloads (11 mmHg and 9 mmHg, respectively), but this difference was not significant (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal aortic aneurysm: still missing the message

Over a 7-month period 50 patients presented to the vascular unit with a ruptured or acute symptomatic abdominal aortic aneurysm (AAA). Information regarding the 24 months before acute presentation was obtained from the patient, family doctor and relevant case records to determine whether an asymptomatic aneurysm had previously been diagnosed but the patient not referred to the vascular service, or whether the patient had undergone an examination at which an aneurysm might reasonably have been expected to be diagnosed. Thirteen patients (26 per cent) had previously had an AAA diagnosed but only five had been referred. Thirteen patients (26 per cent) had had a total of 16 inpatient hospital admissions without an asymptomatic aneurysm being diagnosed. Six patients (12 per cent) underwent abdominal examination for an unrelated complaint by the family doctor without an asymptomatic aneurysm being diagnosed. A significant impact on overall mortality from aortic aneurysm may be made by increasing the number of patients undergoing elective aneurysm repair. All doctors should assess aortic diameter in all patients over 50 years of age who undergo abdominal examination for whatever reason. All patients diagnosed as having an asymptomatic AAA should be referred to a vascular surgeon for assessment.

Racial differences in maximal vasodilatory capacity of forearm resistance vessels in normotensive young adults

This study was performed to determine whether alterations in vascular structure exist in a biracial population of young (age 22.3 +/- 0.6 yrs [mean + SE]) normotensive men. We examined maximal vasodilatory capacity in 21 blacks and 20 whites (average blood pressure = 122/75 and 118/72 mm Hg, respectively). Forearm blood flow was determined at rest and after 10 min of ischemic handgrip exercise using venous occlusion plethysmography. Forearm vascular resistance was computed from blood flow and mean arterial blood pressure determined by auscultation. Minimum forearm vascular resistance was 23% higher in blacks (2.60 +/- 0.60) than in whites (2.11 +/- 0.41) (P = .005), and was unrelated to parental history of hypertension. The regression equation for minimum forearm vascular resistance (Y) and casual blood pressure (X) for blacks was Y = -1.782 + 0.0487X (r = 0.522); for whites it was Y = -1.165 + 0.0367X (r = 0.418). When the data were covaried on resting mean arterial blood pressure, blacks still had a higher minimum forearm vascular resistance (P = .014). The results suggest a racial difference in the vascular structure of the forearm resistance vessels.

Cardiovascular and plasma catecholamine responses to exercise in blacks and whites

The purpose of the present study was to assess possible racial differences in cardiovascular and plasma catecholamine responses to dynamic exercise. A biracial group of normotensive college-age men (15 blacks, 15 whites) were tested for maximal oxygen uptake, resting blood pressure, and heart rate. Subjects then rode a cycle ergometer at 25%, 50%, and 75% of peak oxygen uptake (6 minutes at each stage). Blood pressure and heart rate were measured during supine rest, seated rest, and at each stage of exercise with an automated blood pressure monitor. At each stage, venous blood was sampled to allow determination of plasma norepinephrine and epinephrine, and cardiac output was measured with the carbon dioxide rebreathing technique. The results indicated that resting blood pressure was similar for blacks and whites (114/68 versus 115/68 mm Hg, respectively). Blacks exhibited greater systolic and diastolic blood pressures during submaximal dynamic exercise. However, blacks also showed a trend toward a positive parental history of hypertension, which has been associated with an increased pressor response. Racial differences did not exist for heart rate or cardiac output, but blacks had higher values for total peripheral resistance both at rest and during exercise. Although no overall racial differences were seen for plasma catecholamine concentrations at rest, blacks had significantly lower levels of norepinephrine (1,275 versus 1,556 pg/ml) and higher levels of epinephrine (306 versus 216 pg/ml) than whites at the highest work rate. The current study confirms the increased pressor response to exercise in normotensive blacks. Blacks had an elevation in total peripheral resistance that was not accompanied by an increase in plasma norepinephrine levels.

The antibacterial activity of Virkon measured by colony growth and bioluminescence of lux recombinant Listeria monocytogenes

Concentration exponents for the broad spectrum antimicrobial Virkon were determined for Listeria monocytogenes using both plate counts and bioluminescence measurements; the values of 3.15 and 2.6 indicate a close equivalence between these two measurement procedures. Virkon is an effective biocide for L. monocytogenes at the manufacturer's in-use concentration of 1%.

The benefits and costs of caregiving and care receiving for daughters and mothers

In accordance with social exchange theory (Thibaut and Kelley, 1959), this study examined the outcomes of caregiving for elderly mothers and their caregiving daughters (N = 141 pairs). Data were gathered through face-to-face interviews. Principal components factor analyses revealed three factors for mothers: Helplessness, Feeling Loved, and Anger; and three factors for daughters: Insufficient Time, Frustration, and Anxiety. Block regressions with an initial block of demographic variables and a second block of situational variables were performed to determine the relative influence of these two sets of independent variables on caregiving outcomes. The regressions revealed limited influence of demographic variables and significant influence of situational variables. Of particular importance for daughters is the role of perceived intimacy with the mother: Daughters with better relationships experience fewer caregiving costs. Mothers' health plays a critical role in the outcomes of care receiving: Mothers in poorer health experience greater helplessness and are less likely to feel loved.

Medicare: a strategy for quality assurance, III: Beneficiary and physician focus groups

The third of a series on the Institute of Medicine study on a quality review and assurance program for Medicare, this article describes findings on two separate series of focus groups held with Medicare beneficiaries and with physicians in private practice. The respondents' perceptions of quality of care, understanding of the Medicare program and QA activities, and recommendations for improvement are reported directly and examined for implications for designing a coherent QA strategy. A surprising finding is that both beneficiaries and physicians define quality of care in terms of the "art of care" as well as in technical and clinical terms.

Relationships between caregiving daughters and their elderly mothers

In this qualitative study of 29 pairs of widowed mothers and their caregiving daughters, we employ social exchange theory to identify three relationship types: intrinsic (45%), ambivalent (34%), and conflicted (21%). These types differ in the extent to which the women receive rewards from interacting with their partner, experience costs in their interaction, handle conflicts that arise in their relationship, and express feelings of concern for each other. They also differ in that daughters in intrinsic pairs have fewer children and shorter caregiving histories than daughters in ambivalent or conflicted pairs.

Comparison between Eusol and Silastic foam dressing in the postoperative management of pilonidal sinus

Seventy-five consecutive patients with pilonidal sinus disease were randomized to receive either Eusol dressings or Silastic foam dressings. Patients were divided into those with pilonidal sinus and pilonidal abscess. There was no significant difference between time to hospital discharge or time to full healing in either group. The cost benefits and simplicity of Silastic foam dressing are discussed.

Obesity in black women in Soweto, South Africa: minimal effects on hypertension, hyperlipidaemia and hyperglycaemia

Studies were made on 50 South African urban black obese women aged 25-40 years, with Body Mass Index (BMI) (Kg/m2) of 29.5 or more, and on 50 non-obese women with BMI of 25 or less. In the two groups, mean triceps skinfolds were 25.5mm and 17.8mm, respectively. Hypertension (greater than or equal to 160/95mm Hg) was present in 6 and 4 women (12% and 8%), hypercholesterolaemia (greater than or equal to 5.2mmol/l) in 5 and 3 women (10% and 6%), hypertriglyceridaemia (greater than or equal to 1.8mmol/l) in 5 and 3 (10% and 6%), and hyperglycaemia (greater than or equal to 7.8mmol/l) in 2 and 1 women (4% and 2%). One or more adverse sequelae were present in 11 (22%) obese and in 9 (18%) of non-obese women, proportions not significantly different. Dietarily, mean daily intakes were--Kcals 2273 and 2240, protein 73g and 70g (12.9% and 12.5% energy), fat 65g and 67g (25.7% and 26.9% energy), carbohydrate 349g and 330g (61.4% and 60.5% energy), and dietary fibre, 12g and 13g. In this low socioeconomic and low fat dietary context, obesity in the black women studied was not specifically evocative of deleterious sequelae of obesity.

A prospective study of infrared coagulation, injection and rubber band ligation in the treatment of haemorrhoids

One hundred patients with non-prolapsing and one hundred with prolapsing haemorrhoids were allocated to receive conventional treatment (CT) by injection sclerotherapy or rubber band ligation, or infrared photocoagulation (IRC). Significantly more patients with nonprolapsing haemorrhoids were symptom free after IRC (81%) than CT (59%) at three months. (Chi2 = 4.4, p = 0.05). There was no significant difference in the outcome at 1 or 4 years. Likewise for prolapsing haemorrhoids, there was no significant difference in the outcome of IRC or CT at 3 months, one or 4 years. However, recurrence of prolapse was more common after IRC (54%) than rubber band ligation (RBL) (27%) at 1 year (Chi2 = 3.46, p less than 0.1). IRC was significantly less painful than CT (p less than 0.001). IRC is a safe, rapid, non-invasive alternative to CT, which is acceptable to the patient and give similar results, though RBL provides more rapid and longer lasting relief from prolapse.

Autonomy and decision making between single older women and their caregiving daughters

We examined perceptions of decisional autonomy and decision-making processes among 64 elderly, single mothers and their caregiving daughters. Mothers were highly involved in decisions affecting their lives, ranging from daily care to major health decisions; daughters were particularly influential over major health, financial and housing decisions. Mothers' level of personal care dependency was negatively associated with both mothers' and daughters' confidence in the mothers' decision-making abilities.

Prevalence of gallstones in elderly black women in Soweto, Johannesburg, as assessed by ultrasound

In Western populations, about a third of elderly women have gallstones, as assessed from ultrasonography. In South Africa, cholelithiasis is reported to be increasing in urban blacks. Their recent dietary changes include a rise in fat and a fall in dietary fiber intake. To assess the current situation, we have carried out ultrasonography studies on 100 urban black women, 55-85 yr old, with no clinical evidence of gastrointestinal disease, especially with reference to the biliary system. Ten patients (10%) were positive. There was no association with parity. Their body mass index (27.8 +/- 6.9) was significantly higher (P less than 0.05) than those who were negative (25.7 +/- 6.1). From dietary intake assessments, there were no significant differences between those positive and negative with respect to mean intakes of energy, protein, fat, carbohydrate, dietary fiber or sugar (p greater than 0.05). Continuing exposure to a western lifestyle would be expected to increase prevalences of gallstones.

Small-bowel volvulus secondary to enteroenterostomy for jejunal atresia

Small-bowel volvulus due to rotation of a loop of small intestine about an ileostomy or colostomy is well documented, but volvulus in an adult around an enteroenterostomy for jejunal atresia is not reported. This report documents such a case.

Perforation of the colon after barium meal examination

Retention of barium in the caecum (Dixon et al., 1967; Gupta and Fraser, 1985), appendix (Maglinte et al, 1981) and colonic diverticula (Burrows, 1962) has been reported after barium meal as has colonic perforation during barium enema examination (Ott and Gelfand, 1983). One case of colonic perforation after a barium meal has been reported in association with adenocarcinoma of the sigmoid colon (Violon et al., 1980).

A multicentre study to compare piperacillin with the combination of netilmicin and metronidazole for prophylaxis in elective colorectal surgery undertaken in district general hospitals

We have conducted a multicentre randomized study to compare piperacillin with the combination of netilmicin and metronidazole in patients undergoing elective colorectal surgery. There was no significant difference in the incidence of operation-related infection, chest or urinary tract infection. Major life-threatening sepsis occurred in 6% and the overall incidence of operation-related infection was 24%. Organisms which normally inhabit the bowel lumen were cultured from most of the postoperative infections; however, Staphylococcus aureus was isolated as a causative organism in nine patients in the piperacillin group compared with none in the netilmicin and metronidazole group. We are concerned at the high incidence of infection in both groups, and we believe that other factors in addition to prophylactic antibiotics need to be evaluated if the incidence of infection is to be reduced further.