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PubMed2003

Need for recovery from work: evaluating short-term effects of working hours, patterns and schedules.

In this paper working hours, patterns and work schedules of employees were evaluated in terms of need for recovery from work. Self-administered questionnaire data from employees of the Maastricht Cohort Study on Fatigue at Work (n = 12,095) were used. Poisson regression analyses and multivariate logistic regression analyses revealed that higher working hours a day and working hours a week generally went together with more need for recovery from work. Overtime work was particularly associated with higher need for recovery from work in both genders. Both male and female three-shift or irregular shift workers had higher odds of elevated need for recovery compared to day workers. When additionally controlling for work-related factors, need for recovery levels among shift workers substantially lowered. This study clearly showed that working hours and schedules are associated with need for recovery from work, with different associations for men and women. Especially the associations between work schedules and need for recovery from work were very interrelated with other work-related factors. Future studies could further investigate the possibility that shift work might function as a proxy of other work-related factors that explain the different levels in need for recovery from work, or that job demands are perceived higher among shift workers and may therefore lead to more need for recovery from work.

Adult↗

PubMed1988

Alterations in phosphate metabolism during cellular recovery of radiation damage in yeast.

We have examined alterations in phosphate pools during cellular recovery from radiation damage in intact, wild-type diploid yeast cells using 31P nuclear magnetic resonance (NMR) spectroscopy. Concurrent cell survival analysis was determined following exposure to 60Co gamma-radiation. Cells held in citrate-buffered saline (CBS) showed increased survival with increasing time after irradiation (liquid holding recovery, LHR) with no further recovery beyond 48 h. Addition of 100 mmol dm-3 glucose to the recovery medium resulted in greater recovery. In the presence of 5 mmol dm-3 2-deoxyglucose (2-DG), LHR was completely inhibited. NMR analyses were done on cells perfused in agarose threads and maintained under conditions similar to those in the survival studies. ATP was observable by NMR only when glucose was present in the recovery medium. In control cells, ATP concentrations increased and plateaued with increasing recovery time. With increasing radiation dose the increase in ATP was of lesser magnitude, and after 2000 Gy no increase was observed. These observations suggest that either the production of ATP in irradiated cells is suppressed or there is enhanced ATP utilization for repair of radiation damage. In CBS with 100 mmol dm-3 glucose, a dose-dependent decrease in polyphosphate (polyP) was detectable with no concurrent increase in inorganic phosphate (Pi). In the absence of an external energy source, such as glucose, there was a slight increase in Pi. This suggests that polyP may be used as an alternative energy supply. When 2-DG was present in the recovery medium, polyP decreased, but there was a simultaneous increase in Pi with increasing radiation dose and recovery time. This suggests that the polyP are hydrolyzed as a source of phosphates for repair of radiation damage.

Adenosine Triphosphate↗

PubMed1993

Latent X-ray damage in the rat sciatic nerve results in delay in functional recovery after a heat treatment.

The influence of X-irradiation on the sensitivity of the rat sciatic nerve to local hyperthermia was investigated. A 10 or 20 mm long segment of the nerve was irradiated intraoperatively using 50 kV X-rays. Hyperthermia (30 min at 45 degrees C), was applied to the irradiated part (over a length of 5 mm) of the nerve using a brass thermode. Functional damage to the nerve was assessed using the toe-spreading test, which mainly assesses the motor function of the sciatic nerve. Radiation alone (doses up to 70 Gy) did not lead to detectable damage for at least 90 weeks. Hyperthermia alone (30 min at 45 degrees C) resulted in complete loss of motor function. This function loss was transient and complete recovery took place in about 4 weeks. Recovery time was scored as the number of days between hyperthermia and the day on which 50% of the motor function had returned. Irradiation (35 Gy) of a nerve segment, which included the heated part, resulted in a delayed recovery from the heat treatment compared to controls (heat only). The time interval and sequence between irradiation and hyperthermia hardly influenced the recovery delay. The size of the irradiated nerve segment did influence the recovery delay. Irradiation of a 20 mm nerve segment led to longer recovery delays than irradiation of a 10 mm segment (a delay of 5-10 days and 1-5 days respectively). A dose-response relation for the irradiation-induced delay in recovery was observed when a large segment (20 mm) of the nerve was irradiated immediately after heat with a dose ranging from 5 to 40 Gy. The delay in heat recovery was dose-dependent below 20 Gy, but after radiation doses above 20 Gy the recovery delay remained almost constant.

Animals↗

PubMedDate not supplied

Criteria for recovery from eating disorders according to patients and therapists.

No consensus exists on criteria for recovery from eating disorders. Different criteria are used in effect and outcome studies, suggesting different rates of recovery. The questions for research were: Which criteria for recovery are important to ex-patients and therapists, and which criteria for recovery are actually realized by ex-patients? A list of 52 possible criteria for recovery was compiled from the literature on eating disorders, representing the domains of eating behavior, body experience, physical and psychological well-being, and emotional and social functioning. Ex-patients (n = 41) and therapists (n = 57) were asked to select criteria from this list, that they viewed as important for recovery from eating disorders. Ex-patients were asked which criteria they had realized by the end of their most recent therapy or treatment and in the period thereafter. Ex-patients and therapists agreed on most of the criteria for recovery. At the end of their therapy, more than 50% of the ex-patients had realized 44 of the criteria for recovery but thereafter they improved on 38 criteria. To realize full recovery and to prevent relapse, it is important to consider not only eating behavior and weight, but also psychological, emotional, and social criteria.

Affect↗

PubMedDate not supplied

Is it possible for speech therapy to improve upon natural recovery rates in children who stutter?

BACKGROUND: Speech and language therapists treating children who stutter appear to be assigned a difficult task. Natural spontaneous remission accounts for approximately 60-80% of all children recovering from stuttering. Despite our best efforts, no protocol has ever shown its effectiveness separate from natural recovery rates (i.e. 60-80%). Although speech and language therapists have used a vast array of therapeutic protocols, the incidence and prevalence of childhood stuttering appears to have remained unchanged. Therefore, although in possession of multiple treatment tools, speech and language therapists might be ill-equipped to treat stuttering children effectively and efficiently to the point of recovery. AIM: To assess speech and language therapists' self-reported perceptions of their success in helping children 'completely recover from stuttering' (i.e. no longer exhibiting any overt or covert stuttering symptoms or using therapeutic strategies to modify speech and no longer being viewed by themselves or anyone else as a 'stutterer'). METHODS & PROCEDURES: A questionnaire was sent to 290 speech and language therapists providing stuttering therapy to children attending school in North Carolina, USA, in a system similar to what can be found in many other US states. It addressed therapeutic efficacy in the management of stuttering: the numbers of stuttering children treated and those perceived to be recovered, the therapeutic methods, the time spent in practice, therapy durations and schedules. OUTCOMES & RESULTS: Usable questionnaires were returned by 101 respondents who reported treating a total of 2036 children who stutter. They reported using a full array of techniques known to reduce stuttering. The median reported recovery rate among respondents was 13.9%. Twenty-eight respondents reported no recoveries whatsoever, and 81 reported five recoveries or fewer. The median time spent on a caseload was 3 years. In addition, longer practising therapists reported significantly higher recover rates than those with less time practising. CONCLUSIONS: Remission from stuttering in children being treated in the schools of North Carolina appears to be the exception rather than the rule. The reported recovery rates suggest that not much is being done therapeutically to help children recover from stuttering. The chance of recovery decreases with age, and speech therapy for children who stutter appears to do little to improve their odds of recovery. Speech and language therapists treating these children either do not possess the tools or the tools do not yet exist to change 'nature's recovery agendum' and put children who stutter on the path towards natural sounding, fluent and spontaneous in all situations. As such, the provision of therapy, in North Carolina at least, does not yet allow for stuttering children to shed the label of 'stutterer', in their own eyes and in the eyes of all others for the rest of their lives. In light of these data, the authors suggest re-examining the tools, policies and procedures used in the treatment of stuttering children.

Attitude of Health Personnel↗

PubMed2005

Recurrent event analysis of lapse and recovery in a smoking cessation clinical trial using bupropion.

We report a reanalysis of data from a prior study describing the event history of quitting smoking aided by bupropion, using recurrent-event models to determine the effect of the drug on occurrence of lapses and recoveries from lapse (resumption of abstinence). Data were collected on 1,070 subjects across two similar double-blind randomized clinical trials of bupropion versus placebo and fitted with separate Cox regression models for lapse and recovery. Analyses were split using discrete time-varying covariates between the treatment (weeks 1-10) and follow-up phases (end of treatment to 12 months). Bupropion was associated with slower lapse during treatment for both sexes, and being female was associated with faster lapse across both phases. Drug did not affect time to recovery for males but was associated with faster recovery among females, allowing women to recover as quickly as men. High levels of nicotine dependence did not affect time to lapse but were associated with slower recovery from lapse across treatment and follow-up phases. During the treatment phase, higher levels of baseline depression symptoms had no effect on time to lapse but were associated with slower recovery from lapse. Results highlight the asymmetry in factors preventing lapse versus promoting recovery. Specifically, dependence, depression symptoms, and a sex x drug interaction were found to affect recovery but not lapse. Further research disentangling lapse and recovery events from summary abstinence measures is needed to help us develop interventions that take advantage of bupropion at its best and that compensate where it is weak.

Adult↗

PubMed1964

THE RECOVERY OF CONTRACTILE ABILITY FOLLOWING A CONTRACTURE IN SKELETAL MUSCLE.

When the potassium in Ringer's solution is increased above 25 mM, frog skeletal muscle contracts and then spontaneously relaxes. Elevated external potassium will not produce tension again until the stimulating potassium has been removed and a recovery process has taken place. The kinetics of this recovery reaction have been studied in toe muscles bathed in choline Ringer's solutions in which the levels of Ca and K were varied. In 2.5 mM K the recovery reaction appears to follow first order kinetics and the recovery is slowed by lowering the external Ca. In 1.8 mM Ca the recovery is complete in 60 sec.; in 0.2 mM Ca it is 70 per cent complete. When the external K is increased to 10, 15, or 20 mM, the recovery reaches a maximum at 60 sec. and then declines. As the external K is increased, the maximum recovery achieved declines. At K concentrations above 20 mM there is no recovery. When the external Ca is reduced to 0.2 mM, the area under the contracture tension curve is reduced by 40 +/- 3 per cent (mean +/- SEM). When 1.6 mM Ni is added to 0.2 mM Ca Ringer's, the contracture area is restored beyond the control value. This addition of the Ni to 0.2 mM Ca Ringer's does not, however, restore the recovery reaction to its rate in 1.8 mM Ca.

Animals↗

PubMed1998

Effects of long-term storage at -90 degrees C of bone marrow and PBPC on cell recovery, viability, and clonogenic potential.

Autologous BM and PB HPC are usually stored from weeks to months until reinfusion after myeloablative chemotherapy. HPC have been stored for up to 16 months at -90 degrees C, using a mixture of 5% DMSO, 6% hydroxyethyl starch (HES), and 4% HSA as a cryoprotectant. Long-term storage (LTS) has usually entailed rate-controlled freezing using 10% DMSO and preservation in liquid nitrogen. The effects of LTS at -90 degrees C on the in vitro cell recovery, viability, and colony-forming unit-granulocyte macrophage (CFU-GM) clonogenic potential of autologous HPC that were not transplanted was studied. Sixteen BM and sixteen PB HPC had been cryopreserved for a median of 53 months (range 27-71) and 35 months (range 26-78), respectively. Samples of frozen HPC were thawed after 48 h, and the nucleated cell count, viability by trypan blue exclusion, and culture for CFU-GM were obtained. Following LTS, the cells were thawed and examined using the same assays. No difference in the median percentage recovery of nucleated cells was found in either the BM or PB HPC between the samples stored for 48 h and after LTS (5.73 x 10(9) versus 5.61 x 10(9) and 6.20 x 10(9) versus 5.78 x 10(9), respectively). In addition, no difference in median percentage viability was found in either the BM or PB HPC sampled at 48 h and at the end of LTS (75% versus 74% and 75% versus 76%, respectively). Finally, the median number of CFU-GM cultured from BM HPC at 48 h was 2.41 x 10(5) (range 0.33-11.01 x 10(5)) and at the end of LTS was 1.93 x 10(5) (range 0.32-10.55), representing a median recovery of 93% (range 19%-308%). Similarly, the median number of CFU-GM cultured from PB HPC was 1.66 x 10(5) (range 0-50.57) and at the end of LTS was 0.93 x 10(5) (range 0-44.9), representing a median recovery of 80% (range 36%-165%). This difference in percentage recovery was not significant (p = 0.514). There was poor correlation between the number of nucleated cells harvested and the percentage recovery of nucleated cells, cell viability, or CFU-GM for either the BM or PB HPC. Similarly, there was poor correlation between the number of CFU-GM in the harvest and their percentage recovery following LTS for both BM and PB HPC. Finally, there was poor correlation between the storage time of the BM or PB HPC and the percentage recovery of nucleated cells, cell viability, and CFU-GM. These data suggest that LTS of HPC at -90 degrees C is not associated with decreased recovery of nucleated cells or in vitro viability and is associated with only a modest decrease in clonogenic potential. This indicates that storage of HPC at -90 degrees C for periods in excess of 3 years is possible.

Blood Preservation↗

PubMed2006

Desiccation tolerance in the moss Polytrichum formosum: physiological and fine-structural changes during desiccation and recovery.

BACKGROUND AND AIMS: This study explores basic physiological features and time relations of recovery of photosynthetic activity and CO(2) uptake following rehydration of a desiccation-tolerant moss in relation to the full temporal sequence of cytological changes associated with recovery to the normal hydrated state. It seeks reconciliation of the apparently conflicting published physiological and cytological evidence on recovery from desiccation in bryophytes. METHODS: Observations were made of water-stress responses and recovery using infrared gas analysis and modulated chlorophyll fluorescence, and of structural and ultrastructural changes by light and transmission electron microscopy. KEY RESULTS: Net CO(2) uptake fell to zero at approx. 40 % RWC, paralleling the fluorescence parameter PhiPSII at 200 micromol m(-2) s(-1) PPFD. On re-wetting the moss after 9-18 d desiccation, the initially negative net CO(2) uptake became positive 10-30 min after re-wetting, restoring a net carbon balance after approx. 0.3-1 h. The parameter F(v)/F(m) reached approx. 80 % of its pre-desiccation value within approx. 10 min of re-wetting. In the presence of the protein-synthesis inhibitors chloramphenicol and cycloheximide, recovery of F(v)/F(m) (and CO(2) exchange) proceeded normally in the dark, but declined rapidly in the light. Though initial recovery was rapid, both net CO(2) uptake and F(v)/F(m) required approx. 24 h to recover completely to pre-desiccation values. The fixation protocols produced neither swelling of tissues nor plasmolysis. Thylakoids, grana and mitochondrial cristae remained intact throughout the drying-re-wetting cycle, but there were striking changes in the form of the organelles, especially the chloroplasts, which had prominent lobes and lamellar extensions in the normally hydrated state, but rounded off when desiccated, returning slowly to their normal state within approx. 24 h of re-wetting. Sub-cellular events during desiccation and re-wetting were generally similar to those seen in published data from the pteridophyte Selaginella lepidophylla. CONCLUSIONS: Initial recovery of respiration and photosynthesis (as of protein synthesis) is very rapid, and independent of protein synthesis, suggesting physical reactivation of systems conserved intact through desiccation and rehydration, but full recovery takes approx. 24 h. This is consistent with the cytological evidence, which shows the thylakoids and cristae remaining intact through the whole course of dehydration and rehydration. Substantial and co-ordinated changes in other cell components, which must affect spatial relationships of organelles and metabolic systems, return to normal on a time span similar to full recovery of photosynthesis. Comparison of the present data with recently published results suggests a significant role for the cytoskeleton in desiccation responses.

Adaptation, Physiological↗

PubMed1999

Growth hormone promotes somatic and skeletal muscle growth recovery in rats following chronic protein-energy malnutrition.

The efficacy of recombinant human growth hormone (GH) and/or a diet enriched in protein and energy to improve growth recovery following prolonged malnutrition was examined in male rats food-restricted from birth until 120 d of age. At d 121, restricted rats were randomly assigned to recovery groups receiving either a control or enriched diet with or without daily subcutaneous injections of GH. Rats were killed after 16 or 47 d of recovery. At d 16, GH treatment stimulated liver, heart, plantaris, soleus, carcass and body weight gain and inhibited fat gain when compared to recovery controls. Rats receiving GH also exhibited the highest serum insulin-like growth factor-I (IGF-I) concentrations and total muscle protein. At d 47, GH effects on body and muscle recovery were minimal, and differences among recovery groups in serum IGF-I concentration and total muscle protein were no longer present. Consumption of an enriched diet increased fat pad and liver mass, but did not promote muscle recovery. There were no differences among treatment groups in skeletal muscle IGF-I mRNA levels at d 16 or 47. In summary, GH had positive effects on somatic and skeletal muscle growth early in the recovery process, possibly via endocrine IGF-I-stimulated protein accretion. In contrast, the enriched diet promoted fat deposition with no impact on skeletal muscle growth recovery.

Adipose Tissue↗

PubMed1994

Recovery from a 1-minute bout of fatiguing exercise: characteristics, reliability, and responsiveness.

BACKGROUND AND PURPOSE: The purposes of this study were (1) to describe the characteristics of recovery of peak torque after a 1-minute bout of isokinetic exercise of the quadriceps femoris muscle, (2) to determine the short-term reliability of the recovery of peak torque, and (3) to determine whether the recovery of peak torque more closely associates with maximal endurance exercise capacity than does the decline in peak torque at the end of the fatigue test. SUBJECTS: Thirty-three nondisabled subjects, ranging in age from 23 to 34 years (X = 27, SD = 3.4), participated in the reliability portion (phase 1) of the study. A different group of 21 nondisabled subjects, ranging in age from 21 to 47 years (X = 27.5, SD = 5.2), participated in the correlational portion (phase 2) of the study. METHODS: The short-term reliability of percentage of decline in peak torque and recovery of peak torque was assessed in phase 1. Each subject performed two quadriceps femoris muscle fatigue tests (test-retest) on an isokinetic dynamometer. In phase 2, each subject performed a single fatigue test and a test of maximal oxygen uptake (VO2max) to examine the relationships between VO2max and percentage of decline in peak torque at the end of the fatigue test and recovery of peak torque. RESULTS: Intraclass correlation coefficient values at every 30-second interval during recovery were acceptable (ICC = .67-.87), indicating recovery of peak torque is a consistent measure of quadriceps femoris muscle performance. A high negative correlation (r = -.84) was found between the percentage of decline at 30 seconds of recovery and VO2max, but a lower negative correlation (r = -.48) was found between the percentage of decline in torque at the end of the fatigue test and VO2max. CONCLUSION AND DISCUSSION: These results suggest recovery of peak torque is a reliable measure of muscle performance and closely associates with maximal aerobic exercise capacity.

Adult↗

PubMed1983

Recovery of neuromuscular function in the perfused rat diaphragm after succinylcholine and pancuronium blockade.

The recovery of the rat diaphragm from neuromuscular blockade was studied in order to separate the contributions of drug binding and tissue washout. The in vitro rat diaphragm preparation was perfused with a cholinesterase-free solution via the phrenic vein and stimulated electrically via the phrenic nerve. Muscle paralysis was induced by infusion of a depolarizing blocker succinylcholine or by the nondepolarizing blocker pancuronium. The time for recovery from 25-75% recovery averaged 1.0 +/- 0.1 min for pancuronium and 0.8 +/- 0.1 min for succinylcholine at the fast (1.9 ml/min) perfusion rate. This was prolonged to 2.0 +/- 0.3 min for pancuronium and 1.4 +/- 0.1 min for succinylcholine at the slower (0.76 ml/min) rate. More sensitive paired tests of recovery utilizing recovery time and rate demonstrated no drug difference in three comparisons and a 44% longer recovery time for pancuronium only at the lower perfusion rate. In general, recovery times were similar for both drugs. The rapid recovery from pancuronium blockade in this mammalian system as perfusion rate was increased suggests that recovery from this drug is not impaired by drug binding but is strongly dependent on organ perfusion.

Animals↗

PubMed2003

Exacerbation with granulocyte colony-stimulating factor of prior acute lung injury during neutropenia recovery in rats.

OBJECTIVE: Neutropenia recovery may be associated with an increased risk of respiratory function deterioration. A history of pneumonia complicating neutropenia has been identified as the leading cause of adult respiratory distress syndrome during neutropenia recovery in patients receiving anticancer chemotherapy, suggesting that neutropenia recovery may worsen prior lung injury. DESIGN: Controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: We studied the effect of recovery from cyclophosphamide-induced neutropenia on endotoxin (lipopolysaccharide)- or hydrochloric acid-induced acute lung injury in rats. We also studied the effects of adding granulocyte colony-stimulating factor. MEASUREMENTS AND MAIN RESULTS: Compared with noncyclophosphamide-treated rats, rats undergoing neutropenia recovery had a higher wet/dry lung weight ratio after hydrochloric acid-induced but not lipopolysaccharide-induced acute lung injury. Granulocyte colony-stimulating factor significantly increased both alveolar cell recruitment (bronchoalveolar lavage fluid counts) and pulmonary edema (wet/dry lung ratio) in both acute lung injury models during neutropenia recovery. Furthermore, in an experiment in hydrochloric acid-instilled rats, exacerbation by granulocyte colony-stimulating factor of hydrochloric acid-induced acute lung injury was inhibited by lidocaine, which prevents adhesion of neutrophils to endothelial cells. Tumor necrosis factor-alpha and interleukin-1 beta concentrations in supernatants of lipopolysaccharide-stimulated alveolar macrophages from rats undergoing neutropenia recovery with granulocyte colony-stimulating factor treatment were significantly increased compared with rats undergoing neutropenia recovery without granulocyte colony-stimulating factor. CONCLUSION: Neutropenia recovery can worsen acute lung injury, and this effect is exacerbated by granulocyte colony-stimulating factor.

Animals↗

PubMed2000

Intensity effect of active recovery from glycolytic exercise on decreasing blood lactate concentration in prepubertal children.

PURPOSE: Children's performance after intense exercise is known to recover faster than that of adults. However, very little is known about the physiological processes that differentiate children from adults in their recovery. The purpose of this study was to compare, in children, the decrease in blood lactate concentration ([La]) during various intensities of active recovery from highly intense exercise with that during passive recovery. METHODS: Subjects were 15 healthy, physically active, prepubertal, 9- to 11-yr-old boys (N = 8) and girls (N = 7). Subjects performed three 40-s cycling bouts at 150% peak oxygen consumption (VO2peak), with two 50-s rest intervals, followed by 2 min of passive recovery and 23 min of one of four randomly-assigned recovery levels: passive and 40%, 50%, and 60% VO2peak (RP, R40, R50, and R60, respectively). RESULTS: Mean values of peak [La] (by treatment) ranged between 9.9 +/- 1.5 and 10.8 +/- 2.0. Whereas HR and VO2 remained relatively higher, [La] decreased faster during all active recoveries compared with the passive mode. [La] during R60 was higher compared with [La] during R40. [La] was slightly higher in the first 10 min of R40 compared with R50, whereas from the 15th min onward, this difference was reversed. A similar pattern was seen in the boys and girls, separately. The calculated half-life of [La] was significantly higher during the passive compared with all three active recoveries, with no differences among the latter (22.0 +/- 5.0, 10.3 +/- 1.9, 10.5 +/- 2.2, and 11.5 +/- 2.1 min during RP, R40, R50, and R60, respectively). CONCLUSIONS: In summary, similar to the case in adults, the decrease in [La] after intense exercise in children is faster during active recovery compared with the passive mode. Further research is required to determine whether performance recovery parallels that of [La] in children and adults of both genders.

Age Factors↗

PubMed1993

Sensory recovery in myocutaneous, noninnervated free flaps: a morphologic, immunohistochemical, and electron microscopic study.

The aim of this study was to clarify the following questions: (1) Do newly sprouting axons use the empty neurilemmal sheaths of a flap as conduits? (2) To what extent can sensibility recover? (3) Does sensory recovery occur at the margins of the flap or at its center? (4) Does chemotaxis influence the regeneration process? In 16 free myocutaneous flaps (12 latissimus dorsi, 4 rectus abdominis) we investigated pain (pinprick), constant touch, temperature, 30- and 256-Hz vibration, and static and moving two-point discrimination between 1 1/2 and 8 years after surgery. Four flaps were anesthetic, eight recovered partly, and four had six or more modalities present all over the flap; six of ten flaps with poor recovery showed better sensitivity close to the anastomosis. Nine patients agreed to have two punch biopsies (6 mm) taken from their flaps (seven from areas with different degrees of sensory recovery and two from the center and the periphery when recovery was homogeneous). Biopsies from the areas with better sensory recovery showed slightly more nerves than the other punches in five instances, showed no difference between the two biopsies in one instance, and seemed to have more nerves in the biopsy from the area with less recovery in the last instance. The two pairs of biopsies from the homogeneously recovered flaps showed similar amounts of nerves. S-100 protein-positive neural structures (Schwann cells) were found in 13 biopsies, and neuron-specific enolase-positive nerve fibers (nerve axons) were found in 10 biopsies. Electron microscopy showed mainly unmyelinated fibers, always adjacent to vessels and sometimes with regenerative phenomena. We believe that sprouting axons probably grow into a flap attracted by chemotaxis from hair follicles, the basement membrane, and the laminin contained in the sheath. We recommend maximum scar excision at the recipient site to enhance sensory recovery in flaps. We conclude that (1) the sprouting axons primarily use the empty neurilemal sheaths as conduits, (2) sensory recovery can reach two-point discrimination equal to the donor site of the flap, and (3) sensory recovery occurs mainly from the margin of the flap but also from the bed.

Adult↗

PubMedDate not supplied

Vagal rebound and recovery from psychological stress.

OBJECTIVE: To characterize cardiovascular recovery and examine the possible relationship of vagal activity and reflexes to risk for heart disease. METHODS: Subjects performed cold pressor and mental arithmetic tasks. Heart rate, heart period variability, and pre-ejection period were obtained for 1 minute before, during, and after each task (Experiment 1). In the second experiment, subjects performed a Stroop color-word task and a mental arithmetic task. Heart rate, heart period variability, blood pressure, and baroreflex sensitivity were obtained during the 5-minute baseline, task, and recovery periods (Experiment 2). RESULTS: In Experiment 1, heart rate during recovery was lower than baseline despite continued pre-ejection period shortening, whereas recovery heart period variability was higher than baseline. In Experiment 2, blood pressure increased throughout the session. However, recovery heart rate after mental arithmetic was lower than baseline heart rate, and heart period variability was higher during both recovery periods than during baseline. Vagal rebound, a sharp increase in variability in the first minute of recovery, was reduced in men in Experiment 1 and in individuals with a family history of cardiovascular disease in Experiment 2 and was associated with degree of change in baroreflex sensitivity between task and rest. CONCLUSIONS: Cardiovascular recovery from stress is associated with increased vagal modulation despite residual sympathetic activation. Vagal rebound may be involved in mechanisms resetting the baroreflex sensitivity at the onset and offset of stress. Diminished vagal rebound during recovery from stress is associated with standard risk factors for cardiovascular disease. The results support an association between attenuated vagal reflexes and risk for cardiovascular disease.

Adolescent↗

PubMed1993

Effects of prolonged wakefulness on cyclic alternating pattern (CAP) during sleep recovery at different circadian phases.

Two separate groups of healthy subjects aged between 20 and 30 years underwent a random sequence of two non-consecutive polysomnographic recordings under standard conditions (night basal sleep) and after continuous sleep deprivation (recovery sleep). In the first group of 6 subjects (3 males and 3 females) recovery sleep occurred in the morning (after 24 h of prior waking); in the second group of 6 subjects (3 males and 3 females) recovery sleep occurred in the night (after 36 h of prior waking). In all cases the recording time was restricted to 500 minutes. Scoring was accomplished on conventional sleep variables and on Cyclic Alternating Pattern (CAP) parameters, while statistical analysis was based on a 2 x 2 ANOVA test. Compared to the night basal conditions, total sleep time and total NREM sleep were significantly longer in night recovery sleep and shorter in morning recovery sleep, respectively. No significant differences were found for sleep latency, intra-sleep awakenings, stage 2, REM sleep, NREM stages and slow-wave sleep. Total CAP time, CAP time in slow-wave sleep and all CAP rates were significantly higher in morning recovery sleep and lower in night recovery sleep. The enhanced amounts of CAP time and CAP rates during morning recovery sleep may be the outcome of two opposite forces, i.e. high sleep pressure versus maximum wake propensity. In contrast, the lower values of CAP during night recovery sleep suggest an in-phase associations between strong sleep pressure and the circadian clock.

Journal Article↗

PubMed1997

Can final EMG baseline be used as a reference to calculate neuromuscular recovery?

BACKGROUND: Investigations recording recovery times of muscle relaxants have used initial or final baseline of a neuromuscular trace, or both, as a reference for data analysis. We evaluated the use of final baseline of EMG traces as a reliable reference to calculate recovery times. METHODS: We analyzed EMG traces from 82 children who had full spontaneous neuromuscular recovery following a single dose of mivacurium. Times from administration of mivacurium to 25, 50, 75, and 90% EMG recoveries were measured using both initial and final baselines as a reference. EMG traces with final baseline of 100 +/- 10% of the initial baseline were regarded as optimal. Recovery times from all other traces were compared to the times obtained from these optimal traces. Poor final baseline was defined as that of < 80% of initial baseline. Inter-group comparisons were made using Kruskal-Wallis test followed by Mann-Whitney U tests. RESULTS: EMG recovery times were similar for optimal traces whether the reference was the initial or the final baseline of the EMG trace. If the final baseline was used as the reference, then traces with poor final EMG baseline also showed similar neuromuscular recovery times. If the initial baseline was used as the reference for EMG traces with poor final baseline, then neuromuscular recovery times became 24-55% longer (P < 0.05). CONCLUSIONS: We conclude that the final baseline of an EMG trace can be used as a reference for calculations of neuromuscular recovery times following a bolus injection of mivacurium.

Child↗