The effect of endurance training on parameters of aerobic fitness

Endurance exercise training results in profound adaptations of the cardiorespiratory and neuromuscular systems that enhance the delivery of oxygen from the atmosphere to the mitochondria and enable a tighter regulation of muscle metabolism. These adaptations effect an improvement in endurance performance that is manifest as a rightward shift in the 'velocity-time curve'. This shift enables athletes to exercise for longer at a given absolute exercise intensity, or to exercise at a higher exercise intensity for a given duration. There are 4 key parameters of aerobic fitness that affect the nature of the velocity-time curve that can be measured in the human athlete. These are the maximal oxygen uptake (VO2max), exercise economy, the lactate/ventilatory threshold and oxygen uptake kinetics. Other parameters that may help determine endurance performance, and that are related to the other 4 parameters, are the velocity at VO2max (V-VO2max) and the maximal lactate steady state or critical power. This review considers the effect of endurance training on the key parameters of aerobic (endurance) fitness and attempts to relate these changes to the adaptations seen in the body's physiological systems with training. The importance of improvements in the aerobic fitness parameters to the enhancement of endurance performance is highlighted, as are the training methods that may be considered optimal for facilitating such improvements.

Effects of prior heavy exercise on phase II pulmonary oxygen uptake kinetics during heavy exercise

We tested the hypothesis that heavy-exercise phase II oxygen uptake (VO(2)) kinetics could be speeded by prior heavy exercise. Ten subjects performed four protocols involving 6-min exercise bouts on a cycle ergometer separated by 6 min of recovery: 1) moderate followed by moderate exercise; 2) moderate followed by heavy exercise; 3) heavy followed by moderate exercise; and 4) heavy followed by heavy exercise. The VO(2) responses were modeled using two (moderate exercise) or three (heavy exercise) independent exponential terms. Neither moderate- nor heavy-intensity exercise had an effect on the VO(2) kinetic response to subsequent moderate exercise. Although heavy-intensity exercise significantly reduced the mean response time in the second heavy exercise bout (from 65.2 +/- 4.1 to 47.0 +/- 3.1 s; P < 0.05), it had no significant effect on either the amplitude or the time constant (from 23.9 +/- 1.9 to 25.3 +/- 2.9 s) of the VO(2) response in phase II. Instead, this "speeding" was due to a significant reduction in the amplitude of the VO(2) slow component. These results suggest phase II VO(2) kinetics are not speeded by prior heavy exercise.

Oxygen uptake kinetics in treadmill running and cycle ergometry: a comparison

The purpose of the present study was to comprehensively examine oxygen consumption (VO(2)) kinetics during running and cycling through mathematical modeling of the breath-by-breath gas exchange responses to moderate and heavy exercise. After determination of the lactate threshold (LT) and maximal oxygen consumption (VO(2 max)) in both cycling and running exercise, seven subjects (age 26.6 +/- 5.1 yr) completed a series of "square-wave" rest-to-exercise transitions at running speeds and cycling power outputs that corresponded to 80% LT and 25, 50, and 75%Delta (Delta being the difference between LT and VO(2 max)). VO(2) responses were fit with either a two- (<LT) or three-phase ( >LT) exponential model. The parameters of the VO(2) kinetic response were similar between exercise modes, except for the VO(2) slow component, which was significantly (P < 0.05) greater for cycling than for running at 50 and 75%Delta (334 +/- 183 and 430 +/- 159 ml/min vs. 205 +/- 84 and 302 +/- 154 ml/min, respectively). We speculate that the differences between the modes are related to the higher intramuscular tension development in heavy cycle exercise and the higher eccentric exercise component in running. This may cause a relatively greater recruitment of the less efficient type II muscle fibers in cycling.

Automated percutaneous lumbar discectomy versus chemonucleolysis in the treatment of sciatica. A randomized multicenter trial

A randomized clinical trial was conducted to compare the results of automated percutaneous discectomy with those of chemonucleolysis in 141 patients with sciatica caused by a disk herniation; 69 underwent automated percutaneous discectomy and 72 were subjected to chemonucleolysis. The principle outcome was the overall assessment of the patient 6 months after treatment. Treatment was considered to be successful by 61% of the patients in the chemonucleolysis group compared with 44% in the automated percutaneous discectomy group. At 1-year follow-up, overall success rates were 66% in the chemonucleolysis group and 37% in the automated percutaneous group. Within 6 months of treatment, 7% of the patients in the chemonucleolysis group and 33% in the discectomy group underwent subsequent open surgery. The complication rates of both treatment groups were low, with the exception of a high rate of low-back pain in the chemonucleolysis group (42%). The results of this trial confirm previous controlled studies on chemonucleolysis and suggest that controlled studies should be carried out before automated percutaneous discectomy can be considered a useful intervention.

3D collagen architecture induces a conserved migratory and transcriptional response linked to vasculogenic mimicry

The topographical organization of collagen within the tumor microenvironment has been implicated in modulating cancer cell migration and independently predicts progression to metastasis. Here, we show that collagen matrices with small pores and short fibers, but not Matrigel, trigger a conserved transcriptional response and subsequent motility switch in cancer cells resulting in the formation of multicellular network structures. The response is not mediated by hypoxia, matrix stiffness, or bulk matrix density, but rather by matrix architecture-induced β1-integrin upregulation. The transcriptional module associated with network formation is enriched for migration and vasculogenesis-associated genes that predict survival in patient data across nine distinct tumor types. Evidence of this gene module at the protein level is found in patient tumor slices displaying a vasculogenic mimicry (VM) phenotype. Our findings link a collagen-induced migration program to VM and suggest that this process may be broadly relevant to metastatic progression in solid human cancers.

Extracellular matrix plays a central role in driving cancer development. Here the authors using an in vitro approach show that confining collagen architectures induce fast and persistent cell migration and the formation of multicellular network structures linked to vascular mimicry observed in tumours from patients.

Effect of endurance training on oxygen uptake kinetics during treadmill running

The purpose of this study was to examine the effect of endurance training on oxygen uptake (VO(2)) kinetics during moderate [below the lactate threshold (LT)] and heavy (above LT) treadmill running. Twenty-three healthy physical education students undertook 6 wk of endurance training that involved continuous and interval running training 3-5 days per week for 20-30 min per session. Before and after the training program, the subjects performed an incremental treadmill test to exhaustion for determination of the LT and the VO(2 max) and a series of 6-min square-wave transitions from rest to running speeds calculated to require 80% of the LT and 50% of the difference between LT and maximal VO(2). The training program caused small (3-4%) but significant increases in LT and maximal VO(2) (P<0.05). The VO(2) kinetics for moderate exercise were not significantly affected by training. For heavy exercise, the time constant and amplitude of the fast component were not significantly affected by training, but the amplitude of the VO(2) slow component was significantly reduced from 321+/-32 to 217+/-23 ml/min (P<0.05). The reduction in the slow component was not significantly correlated to the reduction in blood lactate concentration (r = 0. 39). Although the reduction in the slow component was significantly related to the reduction in minute ventilation (r = 0.46; P<0.05), it was calculated that only 9-14% of the slow component could be attributed to the change in minute ventilation. We conclude that the VO(2) slow component during treadmill running can be attenuated with a short-term program of endurance running training.

Effects of prior exercise and recovery duration on oxygen uptake kinetics during heavy exercise in humans

Prior heavy exercise (above the lactate threshold, LT) reduces the amplitude of the pulmonary oxygen uptake (VO2) slow component during heavy exercise, yet the precise effect of prior heavy exercise on the phase II VO2 response remains to be established. This study was designed to test the hypotheses that (1) prior heavy exercise increases the amplitude of the phase II VO2 response independently of changes in the baseline VO2 value and (2) the effect of prior exercise depends on the amount of external work done during prior exercise, irrespective of the intensity of the prior exercise. Nine subjects performed two 6 min bouts of heavy cycling exercise separated by 6 min baseline pedalling recovery (A), two 6 min heavy exercise bouts separated by 12 min recovery (6 min rest and 6 min baseline pedalling, B), and a bout of moderate exercise (below the LT) in which the same amount of external work was performed as during the prior heavy exercise, followed by 6 min heavy exercise (C). In both tests A and B, prior heavy exercise significantly increased the absolute VO2 amplitude at the end of phase II (by approximately 150 ml x min(-1)), and reduced the amplitude of the VO2 slow component by a similar amount. Following 12 min of recovery (B), baseline VO2, but not blood [lactate], had returned to pre-exercise levels, indicating that these effects occurred independently of changes in baseline VO2. Prior moderate exercise (C) had no effect on either the VO2 or blood [lactate] responses to subsequent heavy exercise. The VO2 response to heavy exercise was therefore dependent on the intensity of prior exercise, and the effects on the amplitudes of the phase II and slow VO2 components persisted for at least 12 min following prior heavy exercise.

The vitamin D3 analog, ILX-23-7553, enhances the response to adriamycin and irradiation in MCF-7 breast tumor cells

Ionizing radiation and the anthracycline antibiotic, Adriamycin, generally fail to promote a primary apoptotic response in experimental breast tumor cell lines. Similarly, the primary response of breast tumor cells to vitamin D3 (1,25(OH)2D3) and vitamin D3 analogs such as EB 1089 is growth inhibition. Previous studies have demonstrated that pretreatment of MCF-7 breast tumor cells with vitamin D3 or EB 1089 can increase sensitivity to both Adriamycin and irradiation.

PURPOSE

The capacity of the vitamin D3 analog, ILX 23-7553, to enhance the antiproliferative and cytotoxic effects of Adriamycin or irradiation and to promote apoptosis in MCF-7 breast tumor cells was assessed in the present study.

RESULTS

Pretreatment of MCF-7 cells with ILX 23-7553 followed by Adriamycin or irradiation decreased viable cell numbers by 97% and 93%, respectively. Cell numbers were reduced by 56%, 74% and 75% by ILX 23-7553, Adriamycin and irradiation alone. Pretreatment with ILX 23-7553 also shifted the dose response curve for clonogenic survival, increasing sensitivity to Adriamycin 2.5-fold and sensitivity to radiation fourfold. In addition, ILX 23-7553 pretreatment conferred sensitivity to Adriamycin- or irradiation-induced DNA fragmentation and resulted in morphological changes indicative of apoptotic cell death in MCF-7 cells. Statistical analysis demonstrated that ILX 23-7553 interacts additively and not synergistically with both Adriamycin and irradiation.

CONCLUSIONS

ILX 23-7553 enhances the effects of Adriamycin and irradiation in MCF-7 breast tumor cells by decreasing viable cell numbers, reducing clonogenic survival and inducing apoptotic cell death. Current studies are focused on elucidating the mechanisms underlying the induction of apoptosis as well as understanding the nature of the interactions between ILX 23-7553 and Adriamycin or irradiation.

Examining the correspondence of breastfeeding and bottle-feeding couples' infant feeding attitudes

Examining the correspondence of breastfeeding and bottle-feeding couples' infant feeding attitudes This report focuses on the comparison of infant feeding attitudes within breastfeeding (n = 126) and bottle-feeding (n = 101) couples and their socio-demographic details. The findings from this study reinforce the view that socio-demographic factors are associated with the mothers' choice of feeding method. However, this study highlights the influence of maternal and of paternal knowledge and attitudes which distinguish between breastfeeding and bottle-feeding couples. Fathers of bottle-feeding babies were found to have limited knowledge of health benefits of breastfeeding to both mothers and infants. However, bottle-feeding mothers, when compared with their partners, were more supportive towards bottle feeding and less negative towards breastfeeding. Fathers of breastfeeding babies, compared with their partners were found to be less aware of the benefits of breastfeeding. Furthermore, breastfeeding mothers when compared with their partners were more supportive towards breastfeeding. Fathers of both bottle and breast feeding babies were also found to be more embarrassed than their partners about mothers in general breastfeeding in front of nonfamily members. It seems that bottle-feeding mothers and all fathers could be better prepared in many aspects of breastfeeding by the nursing professions to allay the many misconceptions and the social embarrassment associated with breastfeeding, by providing appropriate information and support.

Oxygen uptake kinetics during treadmill running in boys and men

The purpose of this study was to compare the kinetics of the oxygen uptake (VO(2)) response of boys to men during treadmill running using a three-phase exponential modeling procedure. Eight boys (11-12 yr) and eight men (21-36 yr) completed an incremental treadmill test to determine lactate threshold (LT) and maximum VO(2). Subsequently, the subjects exercised for 6 min at two different running speeds corresponding to 80% of VO(2) at LT (moderate exercise) and 50% of the difference between VO(2) at LT and maximum VO(2) (heavy exercise). For moderate exercise, the time constant for the primary response was not significantly different between boys [10.2 +/- 1.0 (SE) s] and men (14.7 +/- 2.8 s). The gain of the primary response was significantly greater in boys than men (239.1 +/- 7.5 vs. 167.7 +/- 5.4 ml. kg(-1). km(-1); P < 0.05). For heavy exercise, the VO(2) on-kinetics were significantly faster in boys than men (primary response time constant = 14.9 +/- 1.1 vs. 19.0 +/- 1.6 s; P < 0.05), and the primary gain was significantly greater in boys than men (209.8 +/- 4.3 vs. 167.2 +/- 4.6 ml. kg(-1). km(-1); P < 0.05). The amplitude of the VO(2) slow component was significantly smaller in boys than men (19 +/- 19 vs. 289 +/- 40 ml/min; P < 0.05). The VO(2) responses at the onset of moderate and heavy treadmill exercise are different between boys and men, with a tendency for boys to have faster on-kinetics and a greater initial increase in VO(2) for a given increase in running speed.

The effectiveness of preoperative rehabilitation programmes on postoperative outcomes following anterior cruciate ligament (ACL) reconstruction: a systematic review

BACKGROUND

To explore the effectiveness of preoperative rehabilitation programmes (PreHab) on postoperative physical and psychological outcomes following anterior cruciate ligament reconstruction (ACLR).

METHOD

A systematic search was conducted from inception to November 2019. Randomised controlled trials (RCTs) published in English were included. Risk of bias was assessed using Version 2 of the Cochrane risk-of-bias tool, and the Grading of Recommendations Assessment system was used to evaluate the quality of evidence.

RESULTS

The search identified 739 potentially eligible studies, three met the inclusion criteria. All included RCTs scored 'high' risk of bias. PreHab in all three RCTs was an exercise programme, each varied in content (strength, control, balance and perturbation training), frequency (10 to 24 sessions) and length (3.1- to 6-weeks). Statistically significant differences (p < 0.05) were reported for quadriceps strength (one RCT) and single leg hop scores (two RCTs) in favour of PreHab three months after ACLR, compared to no PreHab. One RCT reported no statistically significant between-group difference for pain and function. No RCT evaluated post-operative psychological outcomes.

CONCLUSION

Very low quality evidence suggests that PreHab that includes muscular strength, balance and perturbation training offers a small benefit to quadriceps strength and single leg hop scores three months after ACLR compared with no PreHab. There is no consensus on the optimum PreHab programme content, frequency and length. Further research is needed to develop PreHab programmes that consider psychosocial factors and the measurement of relevant post-operative outcomes such as psychological readiness and return to sport.

TRIAL REGISTRATION

PROSPERO trial registration number. CRD42020162754 .

Laparoscopic ventral rectopexy, posterior colporrhaphy and vaginal sacrocolpopexy for the treatment of recto-genital prolapse and mechanical outlet obstruction

OBJECTIVE

Whilst trans-abdominal fixation +/- resection offers better functional results and lower recurrence than perineal procedures, mesh rectopexy is complicated by constipation. Laparoscopic autonomic nerve-sparing, ventral rectopexy allows correction of the underlying abnormalities of the rectum, vagina, bladder and pelvic floor.

METHOD

A prospective database was used to audit our 7-year experience of this technique. The recto-vaginal septum was mobilized anteriorly to the pelvic floor avoiding nerve damage. A prolene mesh was sutured to the ventral rectum, posterior vagina and vaginal fornix and secured to the sacral promontory. Patients were assessed with questionnaires and Cleveland Clinic scores.

RESULTS

Eighty patients, six males, median age 59 years (range 31-90) underwent laparoscopic prolapse surgery between Jan 1997 and Dec 2005; 55% had full thickness prolapse and 46% rectal anal intussusception. Five had a solitary rectal ulcer. A total of 58% had undergone previous surgery; hysterectomy 33%, posterior colporrhaphy 15%, posterior rectopexy 6%, Delorme's rectal mucosectomy 5% and Birch colposuspension 3%. Half (54%) were incontinent (mean Wexner score 11, range 2-17) and 31% reported symptoms of obstructed defecation; seven had slow transit constipation and underwent resection. The median operative time was 125 min (range 50-210) with one conversion. Median time to diet was 12 h and median length of stay 3 days (1-12). No patient has developed recurrent full thickness prolapse at a median follow-up of 54 months (30-96). Incontinence improved in 39 of 43 patients (91%); median post-operative Wexner score 1 (0-9). Obstructed defecation resolved in 20 of 25 patients (80%). Pelvic pain resolved in all but one. Complications occurred in 21%; faecal impaction 4%, wound infection 2%, bleeding 2%, leak 1%, chest infection 1%, retention 1%. Three developed minor evacuatory difficulties and two, urinary stress incontinence.

CONCLUSION

Laparoscopic ventral rectopexy is safe with relatively low morbidity. In the medium-term, it provides good results for prolapse and associated symptoms of incontinence and obstructed defecation.

Effect of 6 weeks of endurance training on the lactate minimum speed

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s: age 23+/-4 years; body mass 69.7+/-9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23+/-4 years; body mass 72.7+/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO2max, running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol x l(-1); and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO2max, running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol x l(-1) or the lactate minimum speed. In the training group, there was a significant increase in VO2max (from 47.9+/-8.4 to 52.2+/-2.7 ml x kg(-1) x min(-1)), running speed at the maximal lactate steady state (from 13.3+/-1.7 to 13.9+/-1.6 km x h(-1)), running speed at the lactate threshold (from 11.2+/-1.8 to 11.9+/-1.8 km x h(-1)) and running speed at a blood lactate concentration of 3 mmol x l(-1) (from 12.5+/-2.2 to 13.2+/-2.1 km x h(-1)) (all P < 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0+/-0.7 to 10.9+/-1.7 km x h(-1)). The results demonstrate that the lactate minimum speed, when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.

Medium-term results of stapled transanal rectal resection (STARR) for obstructed defecation and symptomatic rectal-anal intussusception

AIM

Stapled transanal rectal resection (STARR) is an increasingly accepted treatment for obstructed defaecation syndrome (ODS) associated with internal rectal prolapse (IRP) and rectocoele. The aim of this study is to evaluate the medium to long-term outcomes of STARR for ODS.

METHOD

The intermediate-term results of STARR used over a 9-year period were reviewed from the analysis of a prospectively maintained database. Patients were followed for a median period of 98 (95% CI 85-112, range 5-386) weeks.

RESULTS

Three hundred and forty-four (234 woman) patients of median age 54 (19-90) years underwent STARR over a 9-year period. Preoperative symptoms included pelvic pain (93%), incomplete evacuation (90%), urgency (74%), a sensation of obstruction (65%) and rectal digitation (27%). Thirteen had the solitary rectal ulcer syndrome. Of 326 patients with follow-up data, 249 (76%) were followed beyond 1 year and 149 (43%) beyond 2 years. The ODS score improved [14.6 ± 5.4 pre vs 1.6 ± 3.1 post (P < 0.0001)] as did the faecal incontinence (FI) score [3.5 ± 3.3 pre vs 0.4 ± 1.3 post (P < 0.0001)]. Fifteen (4.3%) patients reported deterioration in FI, and 11 (3.2%) experienced new onset minor incontinence. Urgency was 72% at 8 weeks, 20% at 16 weeks, 11.5% at 52 weeks and 5% at 1.5 years. None of the 29 patients followed beyond 4 years reported urgency. Urgency was unrelated to sex, age or preoperative ODS symptoms (Mantel-Cox log-rank). Recurrent symptoms of ODS occurred in 4.9%. Eighty-one per cent of patients were highly satisfied with STARR and would recommend or have it again.

CONCLUSION

STARR was successful for the treatment of selected patients with ODS and IRP. Postoperative faecal urgency rapidly decreases with time. It is not possible to predict who will develop urgency.

Allergic encephalomyelitis in monkeys induced by a peptide from the A1 protein

A major disease-inducing site for induction of experimental allergic encephalomyelitis in monkeys exists in Peptide P 14, the 37-residue segment of the A1 protein comprising its COOH-terminus. The peptide appears to contain the dominant encephalitogenic determinant, since it was as active as the A1 protein on a molar basis. By contrast, the 9-residue tryptophan region and the Peptide R region, active in guinea pigs and rabbits, respectively, were comparatively inactive in monkeys. The clinical and histologic expression of the disease produced by Peptide P 14 appeared identical to that induced by the intact A1 protein.

Androstenetriol and androstenediol. Protection against lethal radiation and restoration of immunity after radiation injury

Androstenetriol (AET) and Androstenediol (AED) upregulate host immunity, leading to increased resistance against infections. AET augments IL-2, IL-3, IFN gamma levels, and counteracts hydrocortisone immune suppression. AET and AED at a dose of 0.75 mg/- and 8.0 mg/25-g mouse, protected 60 and 70%, respectively, of C57/BL/6J mice irradiated with a lethal dose. These hormones also protected mice irradiated with 6 Gy and infected with a coxsackievirus B4 LD50. AET significantly increased spleen lymphocyte numbers at 7, 14, and 21 days after a 6-Gy exposure. Fluorescent activated cell-sorter analysis of irradiated mice, spleen, and bone marrow showed that AET significantly augmented the myeloid precursor markers, CD11b/Mac-1, and B220 (pan B), as well as the absolute numbers of CD4+/CD8+ cells over the 21 days of testing. Overall, the data are consistent with AET/AED inducing a more rapid recovery of all hematopoietic precursors from the small number of surviving stem cells.

Health professionals' responses to multiple sclerosis and motor neurone disease

This study compares the responses of health professionals to multiple sclerosis (MS) and motor neurone disease (MND) in order to determine similarities and variations in responses to the two disorders and the issues critical to caring for patients with these conditions. Health professionals were more negative about MND compared with MS in terms of the amount they felt able to offer patients, their confidence in managing patients and their ability to convey hope. For a number of issues concerning the management of patients, the level of difficulty experienced by health professionals was similar for both MS and MND. These were resource issues, the health professionals' ability to remain positive in the face of progressive disability, interdisciplinary team problems and difficulties regarding patient care. The main concern of health professionals, for both conditions, was the effect of progressive disability on the patient. For MND, management issues which health professionals found comparatively more difficult than for MS were patients' short prognosis and impending death, communication problems and progressive disability. Issues which were comparatively more difficult for MS than MND were changes in patients' affect, cognition and personality, problems with planning care because of the disorder's unpredictable course, problems with diagnosis such as making and disclosing the diagnosis, and the tendency for patients to be difficult or demanding. Some notable differences in responses between health professionals in different health care settings were found. The findings have implications for changing health professionals' conceptualization of 'hope', developing ways of improving communication between health professionals in different health care settings so as to enable them to learn from each other's expertise and experiences and redressing gaps in service provision, especially for young people with MS.

Post-herpetic trigeminal neuralgia treated with deep brain stimulation

Post-herpetic neuralgic affects up to 20% of patients after an attack of trigeminal Herpes Zoster infection. Past medical and surgical treatments have been unrewarding. We report the successful treatment of such a case with deep brain stimulation into the region of the contralateral periventricular grey area (PVG) and ventral posterior lateral thalamic nucleus (VPL).

Effect of incremental test protocol on the lactate minimum speed

PURPOSE

The purpose of this study was to investigate the effect of altering the initial running speed (RS) in the incremental portion of the lactate minimum test on the lactate minimum speed (LMS).

METHODS

Eight well-trained endurance runners (mean +/- SD age 29.0 +/- 5.4 yr, body mass 72.0 +/- 5.6 kg, VO2max 63.1 +/- 3.8 mL x kg(-1) min(-1)) completed a standard incremental treadmill test for the assessment of the lactate threshold (LT) and VO2max, and eight lactate minimum tests. Following a period of supramaximal exercise, subjects were allowed 8 min of recovery to allow blood [lactate] to peak. Subjects then undertook eight randomly-assigned incremental treadmill tests from different initial running speeds (3.0, 2.5, 2.0, 1.5, 1.0, and 0.5 km x h(-1) below the predetermined RS-LT, at the RS-LT, and at 1.0 km x h(-1) above the RS-LT) with RS increased by 1.0 km x h(-1) every 5 min until volitional fatigue. Blood samples for the determination of blood [lactate] were taken at the end of each stage and the LMS was determined by fitting a spline function to the data.

RESULTS

No LMS could be determined for the two highest initial RS conditions. For the other conditions, the LMS was significantly affected by the initial RS used in the incremental test and varied from 13.8 +/- 0.7 km x h(-1) with an initial RS of 3.0 km x h(-1) below the RS-LT, to 15.8 +/- 0.8 km x h(-1) with an initial RS of 0.5 km x h(-1) below the RS-LT. The LMS was significantly different from the RS-LT (15.4 +/- 0.8 km x h(-1)) (P < 0.05), except when the incremental test started at 1.0 or 1.5 km x h(-1) below the RS-LT.

CONCLUSIONS

These results suggest that the LMS test is not a valid method for estimation of the LT since it is profoundly influenced by the starting speed selected for the incremental portion of the test.

Confronting patriarchal attitudes in the fight for professional recognition

Contemporary nursing practice and education belong to a dynamic process which is likely to change the structure of nursing, as well as the relationships that have been established with other professions. This paper is concerned with the professionalization of nursing and examines how nurses and doctors maintain, or challenge, patriarchal relationships in a clinical context. It also examines the wider social climate which upholds the subordination of women in the caring environment. The implementation of alternative therapies, emphasis on patient education, rehabilitation and individualized care all contribute to a climate in which nurses are able to develop an area that can be deemed as their own. Furthermore, the achievement of research-based practice, and the implementation of primary nursing in many areas, indicate a collective approach to patient care. By linking these developments with a feminist discourse nurses are able to challenge their position within the sexual division of labour and highlight the ambiguous position they occupy.

Measles, mumps, and rubella: the need for a change in immunisation policy

There is growing evidence that the present policy of childhood immunisation in the United Kingdom is inadequate. It is unlikely ever to achieve complete eradication of the congenital rubella syndrome and measles, and the problem of mumps has not even begun to be addressed. After a coordinated campaign to increase uptake of immunisation in Fife the uptake of rubella immunisation in teenage girls increased from 75% in 1981 to 94% in 1985 and the uptake of measles vaccination in preschool children from 55% in 1981 to 81% in 1985. There are a few girls each year who do not accept rubella immunisation, whose immune state is unknown, and who are consequently at risk of rubella during future pregnancies. Despite the increased uptake of measles vaccine over the past four years there is currently an epidemic of measles in Fife, with 544 notified cases in the first quarter of 1986. In 1984, 19 Fife residents were admitted to hospital because of complications of mumps. The time is ripe for a complete reassessment of the national immunisation policy.

Risk factors for encephalitis from West Nile Virus: a matched case-control study using hospitalized controls

We conducted a case-control study to determine risk factors for developing encephalitis among West Nile virus cases when compared with age-, gender and race/ethnicity-matched hospitalized controls. In the multivariable conditional logistic regression analysis, we identified the following independent risk factors associated with being an encephalitis case: hypertension (OR 4.0; P = 0.005), immunosuppressing conditions (OR 5.6; P = 0.001) and cardiovascular disease (OR = 28.3; P < 0.001). Individuals with these comorbidities should be targeted for education on protecting themselves from mosquito exposures.

Diversity among hospice volunteers: a challenge for the development of a responsive volunteer program

Voluntary organizations such as hospices are increasingly being called upon to substitute for state health and social welfare delivery at a time when volunteer contributions are threatened because of organizational and demographic changes. These changes include: the adoption by the nonprofit sector of market strategies in response to health and social welfare reforms, increases in the size and complexity of hospices, increasing professionalization of staff, and the move of women away from voluntary work in the health and welfare services to paid employment. With these changes, hospices must be knowledgeable about their volunteer workforce and resourceful if they are to continue to attract and retain volunteers. A survey of volunteers conducted at the Mary Potter Hospice, Wellington, New Zealand, examined differences in volunteers' characteristics, motivations for joining hospice, and factors affecting work satisfaction according to age, gender, and the length of time volunteers had worked. Those findings of particular relevance to program development were: (1) the tendency for the recently recruited volunteers to be in paid employment; (2) the mixed motivations of the younger volunteers, reflecting both altruistic and personal gain needs; and (3) the rewards commonly identified by volunteers, such as feeling their work is of value, being accepted by hospice staff, and feeling like important team members. Practical outcomes of the study are described.