Comparison of caloric expenditure in intermittent and continuous walking bouts

This study compared the caloric expenditure of 30 consecutive minutes (30 minute) of moderate intensity walking with 3 intermittent 10-minute bouts (3 x 10 minutes) of moderate intensity walking in healthy, unfit men (40-49 years). Screening consisted of VO(2)max testing, which was measured using the Balke graded exercise test. Criteria for participation in this study included a measured VO(2)max less than 33.8 ml.kg(-1).min(-1) (<25th percentile for cardiorespiratory fitness). Twenty men participated in this study. Testing consisted of 4 trials with a minimum of 5 days between each trial. The 30-minute and 3 x 10-minute bouts were each performed twice to measure test-retest reliability. Once reliability was found, the 2 30-minute and the 2 3 x 10-minute trials were averaged for further data analyses; t-tests showed no significant differences in energy expenditure between 1 continuous 30-minute and the 3 x 10-minute walking bouts at 274 and 279 kcal (p = 0.09), respectively. Thus, 3 x 10-minute intermittent walking bouts throughout the day are equally beneficial, in terms of caloric expenditure, as 1 30-minute continuous walking bout.     

The long-term effect of acute hypoxic hypoxia on shuttlebox avoidance learning in rats

Long-term influence was studied of the acute hypoxic hypoxia seance on rats behaviour in situation of elaboration of the conditioned reaction of active avoidance of electric shocks in shuttle chamber. It was found that in 2.5-3 months after the hypoxia seance, the experimental animals significantly differed from the intact controls by dynamics of CR elaboration (rats which had hypoxia were ahead of the control ones) and by distribution of the conditioned reactions latencies (for experimental animals this distribution was shifted to minor values). The character of these behavioural shifts coincided with that observed in the group of rats with local unilateral hippocampus lesion. The obtained results and numerous data presented in literature on the influence of the hippocampus lesion on animals shuttle avoidance learning, allow to conclude that the seance of hypoxic hypoxia leads to the disturbance of the hippocampus function. This conclusion conforms to the data on diffusive death of the hippocampal and neocortical neurones as a result of hypoxia action.     

Effects of acute exposures to elevated temperatures on rat embryo growth and development in vitro

Day 10 rat embryos (8-12 somites) cultured in vitro were exposed to elevated temperatures (41-43 degrees C) for varying lengths of time. A 15-minute exposure to a temperature of 43 degrees C (109.4 degrees F) was sufficient to produce malformed embryos when observed on day 11. Longer exposures at this temperature produce higher incidences of malformed embryos and also more severely affected embryos. Temperatures of 42 degrees C (107.6 degrees F) or 41 degrees C (105.8 degrees F) also produced malformed embryos, but the required length of exposure was increased compared to 43 degrees C. The minimal length of exposure at 42 degrees C was 60 minutes, while at 41 degrees C it was increased to 4 hours. The central nervous system was particularly sensitive to increased temperatures, and embryos exposed to "teratogenic doses" of hyperthermia exhibited primarily microcephaly and microphthalmia. In addition, histological analyses revealed that at 4.5 hours after a 30-minute exposure to 43 degrees C, necrotic debris was prevalent in the neuroepithelium, less prevalent in the surrounding mesenchyme and surface ectoderm, and absent in the tissues of the heart.     

The influence of recovery duration after heavy resistance exercise on sprint cycling performance

ABSTRACT: Thatcher, R, Gifford, R, and Howatson, G. The influence of recovery duration after heavy resistance exercise on sprint cycling performance. J Strength Cond Res 26(11): 3089-3094, 2012-The aim of this study was to determine the optimal recovery duration after prior heavy resistance exercise (PHRE) when performing sprint cycling. On 5 occasions, separated by a minimum of 48 hours, 10 healthy male subjects (mean ± SD), age 25.5 ± 7.7 years, body mass 82.1 ± 9.0 kg, stature 182.6 ± 87 cm, deadlift 1-repetition maximum (1RM) 142 ± 19 kg performed a 30-second sprint cycling test. Each trial had either a 5-, 10-, 20-, or 30-minute recovery after a heavy resistance activity (5 deadlift repetitions at 85% 1RM) or a control trial with no PHRE in random order. Sprint cycling performance was assessed by peak power (PP), fatigue index, and mean power output over the first 5 seconds (MPO5), 10 seconds (MPO10), and 30 seconds (MPO30). One-way analysis of variance with repeated measures followed by paired t-tests with a Bonferroni adjustment was used to analyze data. Peak power, MPO5, and MPO10 were all significantly different during the 10-minute recovery trial to that of the control condition with values of 109, 112, and 109% of control, respectively; no difference was found for the MPO30 between trials. This study supports the use of PHRE as a strategy to improve short duration, up to, or around 10-second, sprint activity but not longer duration sprints, and a 10-minute recovery appears to be optimal to maximize performance.     

Use of rhodamine B as a biomarker for oral plague vaccination of prairie dogs

Oral vaccination against Yersinia pestis could provide a feasible approach for controlling plague in prairie dogs (Cynomys spp.) for conservation and public health purposes. Biomarkers are useful in wildlife vaccination programs to demonstrate exposure to vaccine baits. Rhodamine B (RB) was tested as a potential biomarker for oral plague vaccination because it allows nonlethal sampling of animals through hair, blood, and feces. We found that RB is an appropriate marker for bait uptake studies of <60 days in black-tailed prairie dogs (C. ludovicianus) when used at concentrations <0.5% of bait mass dosed to deliver >10 mg RB per kg target animal mass. Whiskers with follicles provided the best sample for RB detection.     

The response of GS-NS0 myeloma cells to single and multiple pH perturbations

Animal cells are cultured in several types of vessels at laboratory and industrial scale the most common being the stirred tank and the air-lift. Economically, it is preferable to culture animal cells at the largest possible scale but the perceived sensitivity of animal cells to hydrodynamic shear has, until now, limited the aeration and agitation rates used. This has been reported to cause inhomogeneities in operational parameters such as dissolved oxygen concentration, temperature and pH. pH is of special interest during the latter stages of many animal cell fermentation because alkali additions, used for pH control, can cause large local pH perturbations of varying size and duration. The effect of single and multiple pH perturbations on the cell growth of a widely used GS-NS0 mouse myeloma cell line grown in batch culture was investigated. The effect of perturbation amplitude and duration was investigated using a single stirred tank reactor (STR). In the single STR system cells were subjected to one pH 8.0 or 9.0 perturbation ranging in duration from 0-90 minutes. No measurable decrease in viable cell number was seen for pH 8.0 perturbations of any duration whereas pH 9.0 perturbations lasting for 10 minutes caused a 15% decrease in viable cell number. The proportion of viable cells decreased with increasing perturbation time and a 90-minute exposure killed all of the cells. The effect of multiple pH perturbations on GS-NS0 cells was investigated using two connected STR's. More specifically the number of perturbations and the perturbation frequency were investigated. Cells were subjected to between 0 and 100 perturbations at pH 8.0; the time between each perturbation (frequency) was 6 minutes and each perturbation lasted for 200 seconds. Viable cell number decreased with increasing perturbation number, with 100 perturbations causing death of 27.5% of cells. Cells were also exposed to 10 perturbations at pH 9.0, each of 200 second duration at frequencies of either 6, 18 or 60 minutes. Approximately 8 times more cells were killed with perturbations at a 6-minute frequency (28.3% cell death) than at a 60-minute frequency (3.4% cell death).     

Pacing pattern in a 30-minute maximal cycling test

The purpose of this study was to investigate the pacing pattern and associated physiological effects in competitive cyclists who performed a 30-minute maximal cycling test. Measurements included oxygen uptake (V O2), heart rate (HR), blood lactate concentration (BLC), rating of perceived exertion (RPE), and work rate in watts. Twelve well-trained amateur cyclists (seven men and five women) whose mean age was 32.4 +/- 8.6 years participated in this study. They performed a 30-minute self-paced maximal cycling test using their own performance road bike attached to a CompuTrainer Pro, which allowed the assessment of work rate (W). During the test, work rate, V O2, and HR were measured every 30 seconds. Subjects' BLC and RPE were obtained every 5 minutes. Results indicate that no significant differences existed across three 10-minute periods for work rate, HR, or V O2. However, RPE at 30 minutes was significantly greater than RPE at 10 and 20 minutes (both p < 0.05). The RPE at 20 minutes was also greater than the RPE at 10 minutes (p < 0.01). Work rate remained relatively constant, with minimal fluctuations occurring throughout the test except for a surge during the final 30 seconds of the test. The associated V O2 was fairly constant over time, whereas HR rose linearly and gradually. It was concluded that pacing in a 30-minute maximal exercise bout performed in the laboratory in experienced cyclists varies minimally until the last 30 seconds. Knowledge of pacing strategy and the linked physiological responses may be helpful to exercise scientists in optimizing performance in the endurance athlete.     

The effect of harp music on heart rate, mean blood pressure, respiratory rate, and body temperature in the African green monkey

BACKGROUND: The effectiveness of recorded harp music as a tool for relaxation for non-human primates is explored in this study. METHODS: Konigsberg Instruments Model T27F-1B cardiovascular telemetry devices were implanted into nine African green monkeys (Chlorocebus aethiops). After post-surgical recovery, animals were exposed to recorded harp music. Telemetry data were collected on heart rate, mean blood pressure, respiratory rate, and body temperature for a 30-minute baseline period before music exposure; a 90-minute period of music exposure; and a 90-minute post-exposure period, where no music was played. RESULTS: No statistical differences were noted in heart rate, mean blood pressure, respiratory rate, and body temperature between pre-exposure, exposure, and post-exposure periods. CONCLUSIONS: The lack of response in these African green monkeys may be attributable to their generally calm demeanor in captivity; experiments with a more excitable species such as the rhesus macaque might demonstrate a significant relaxation response to music.     

The effect of static, ballistic, and proprioceptive neuromuscular facilitation stretching on vertical jump performance

The purpose of this study was to compare the acute effects of different modes of stretching on vertical jump performance. Eighteen male university students (age, 24.3 +/- 3.2 years; height, 181.5 +/- 11.4 cm; body mass, 78.1 +/- 6.4 kg; mean +/- SD) completed 4 different conditions in a randomized order, on different days, interspersed by a minimum of 72 hours of rest. Each session consisted of a standard 5-minute cycle warm-up, accompanied by one of the subsequent conditions: (a) control, (b) 10-minute static stretching, (c) 10-minute ballistic stretching, or (d) 10-minute proprioceptive neuromuscular facilitation (PNF) stretching. The subjects performed 3 trials of static and countermovement jumps prior to stretching and poststretching at 5, 15, 30, 45, and 60 minutes. Vertical jump height decreased after static and PNF stretching (4.0% and 5.1%, p < 0.05) and there was a smaller decrease after ballistic stretching (2.7%, p > 0.05). However, jumping performance had fully recovered 15 minutes after all stretching conditions. In conclusion, vertical jump performance is diminished for 15 minutes if performed after static or PNF stretching, whereas ballistic stretching has little effect on jumping performance. Consequently, PNF or static stretching should not be performed immediately prior to an explosive athletic movement.     

Ultrastructural changes in the cerebral cortex of the cat 30 to 60 minutes after anoxia

The ultrastructural changes in the cat sensorimotor cortex during 30- to 60-minute recovery after a 2.5- to 6-minute anoxia have been studied. The most prominent changes were hypertrophy of Golgi apparatus, reorganization of the neuronal endoplasmic reticulum (including the formation of lamellar bodies), increase of the number of lysosomes within nerve cell bodies, formation of deep invaginations of the neuronal cytoplasm into the nucleus, intensification of endocytosis and phagocytosis in the dendrites, appearance of the ultrastructural heterogeneity of the synapses (from normal synapses to depleted ones), normalization of ultrastructure of the part of mitochondrial pool. Glycogen granules were revealed in glial cell processes. The ultrastructural changes after a 6-minute anoxia followed by a 30- to 60-minute recovery were more expressed than after a 2.5-minute one.     

Comparison of Safety and Immunogenicity of PVRV and PCECV Immunized in Patients with WHO Category II Animal Exposure: A Study Based on Different Age Groups

Background

The aim of this study was to compare the safety and immunogenicity between purified vero cell rabies vaccine (PVRV) and purified chick embryo cell vaccine (PCECV) in patients with WHO category II animal exposure, especially in different age groups.

Methodology/Principal Findings

In one-year clinical observation after vaccination with PVRV or PCECV under Zagreb (2-1-1) or Essen (1-1-1-1-1) regimens, information collection for the demographic and adverse events (AEs) and rabies virus laboratory examination of neutralizing antibody (RVNA) titers were performed for all patients with WHO category II animal exposure in Wuhan city. The results showed no significant differences of safety and immunogenicity between PVRV and PCECV both in Zagreb and Essen regimens. However, when compared with other age groups, most systemic AEs (36/61) occurred in <5-year-old patients, and <5-year-old patients have significant lower RVNA titer and seroconversion rate (RVNA ≥0.5 IU/ml) at day 7 both in Zagreb and Essen regimens or PVRV and PCECV groups.

Conclusions

Our data showed that vaccination with PVRV is as safe and immunogenic as PCECV in patients of all age groups, but might be more popular for clinical use. When performing a vaccination with rabies vaccine in young children, the most optimal vaccine regimen should be selected.     

Phorbol myristate acetate stimulation of lymphocyte guanylate cyclase

Human lymphocyte guanylate cyclase activities are increased in a dose-dependent fashion by incubation of intact cells with phorbol myristate acetate, a tumor promoter and lymphocyte mitogen. Increased activity is detectable after 1 minute, and peak membrane-bound and soluble forms of guanylate cyclase occur after 10- and 30-minute exposure to phorbol myristate acetate, respectively. The soluble form is stimulated much more than the membrane form. Enzyme activities measured in the presence of either Ca²⁺, Mg²⁺, or Mn²⁺ are elevated to similar degrees. Comparisons of phorbol and a series of its diesters revealed a good correlation between the capacities for guanylate cyclase stimulation, lymphocyte mitogenesis, and tumor promotion.     

A comparison of methods for estimating the lactate threshold

The purpose of this study was to examine the accuracy of tests that may be used by distance runners to estimate the lactate threshold. Competitive distance runners/triathletes (N = 27) performed a criterion test that directly measured (blood lactate of 4.0 mmol.L(-1)) the lactate threshold. Subjects then performed 4 tests (VDOT, 3,200-m time trial, 30-minute time trial, Conconi) that estimate the threshold. Mean estimations of the running velocity at the lactate threshold from the 30-minute time trial (standard error of the estimate, SEE, 0.21 m.s(-1)) and VDOT (SEE 0.41 m.s(-1)) methods did not differ (P>0.05) from the criterion. In terms of heart rate, the 30-minute time trial estimation did not significantly differ (SEE 8.0 b.min(-1)) from criterion. These findings suggest that the 30-minute time-trial method should be considered by coaches and distance runners/triathletes as a method for estimating both the running velocity and heart rate at the lactate threshold.     

Laser hyperthermia of tumors with the use of golden nanoparticles under the control of optical coherent tomography and acoustothermometry

The local laser hyperthermia of an experimental tumor RShM-5 of mice with the use of golden plasmin resonance nanoparticles has been carried out. The accumulation of particles in the tumor was controlled by the in vivo noninvasive method of optical coherent tomography. Using this method, the time of the maximum content of nanoparticles in the tumor was determined to be 5 h after the intravenous administration during which the laser hyperthermia was performed. The control of the tumor temperature during the hyperthermia seance showed that the application of nanoparticles provides an effective temperature elevation inside the node and a more targeted heating. The local laser hyperthermia with nanoparticles induced the inhibition of the tumor growth from day 5 to day 7 after the seance with a maximum value of 56%.     

Disinfection Alternatives for Control of Ditylenchus dipsaci in Garlic Seed Cloves

Hot-water dips with and without the additives abamectin and sodium hypochlorite were evaluated for control of Ditylenchus dipsaci infection of garlic seed cloves. All treatments were compared to hot water-formalin clove dip disinfection and to nontreated infected controls for garlic emergence, midseason infection, bulb damage, and yield at harvest in field plots in 12 experiments. Hot-water treatments without additives only partially controlled D. dipsaci when a warming presoak dip (38 C) of 30, 45, or 60 minutes'' duration was followed by a hot-water dip (49 C) of 15-30 minutes'' duration. Exposure to 49 C for 30 minutes caused slight retardation of garlic emergence, although normal stand was established. Abamectin at 10-20 ppm as the 20-minute hot dip (49 C) or as a 20-minute cool dip (18 C) following a 20-minute hot-water dip and sodium hypochlorite at 1.052-1.313% aqueous solution as the 20-minute hot dip were highly effective in controlling D. dipsaci and were noninjurious to garlic seed cloves. None of these treatments was as effective as a hot water-formalin dip and were noneradicative, but showed high efficacy on heavily infected seed cloves relative to nontreated controls. Abamectin was most effective as a cool dip. These abamectin cool-dip (following hot-water dip) and sodium hypochlorite hot-dip treatments can be considered as effective alternatives to replace formalin as a dip additive for control of clove-borne D. dipsaci. Sodium hypochlorite was less effective as the cool dip, and at concentrations of 1.75-2.63% was phytotoxic to garlic.     

Comparative effects of pulsed and continuous-wave 2.8-GHz microwaves on temporally defined behavior

The effects of pulsed-(PW) and continuous-wave (CW) 2.8-GHz microwaves were compared on the performance of rodents maintained by a temporally defined schedule of positive reinforcement. The schedule involved food-pellet reinforcement of behavior according to a differential-reinforcement-of-low-rate (DRL) contingency. The rats were independently exposed to PW and to CW fields at power densities ranging from 1 to 15 mW/cm². Alterations of normal performance were more pronounced after a 30-minute exposure to the PW field than to the CW field. The rate of emission of appropriately timed responses declined after exposure to PW at 10 and 15 mW/cm², whereas exposure at the same power levels to the CW field did not consistently affect the rate of responding. Change in performance associated with microwave exposure was not necessarily related to a general decline in responding: in some instances, increases in overall rates of responding were observed.     

Acute effects of heavy preloading on vertical and horizontal jump performance

The purpose of this study was to investigate the acute effects of a heavy dynamic preload, consisting of 1 set of 5 repetition maximum (5RM) back squats, on countermovement vertical jump (VJ) and horizontal jump (HJ) performance. The study also investigated the ability of subjects to learn to apply the effects of the preload over subsequent training sessions. Nineteen (N = 19) resistance-trained men (age = 25.0 +/- 4.8 years; weight = 79.3 +/- 6.6 kg) participated in the study. Each subject took part in 4 practice and 4 testing sessions. The 4 practice sessions were included to allow for any learning effects of VJ and HJ to stabilize and to establish a true 5RM back squat. The 4 testing sessions were included to see if subjects were able to capitalize on the repeat exposure to the protocol. One practice session consisted of a 10-minute warm-up (5 minutes of cycling and 5 minutes of stretching), 2 sets of VJ and HJ (each set of VJ and HJ consisted of 4 jump repetitions) with a 5-minute rest between sets, progressive 5RM back squat evaluation, and 2 final sets of VJ and HJ. Both VJ and HJ increased approximately 2% over the 4 practice sessions, and 5RM back squat strength improved from 164.2 +/- 25.1 kg to 196.9 +/- 23.0 kg (p < or = 0.05). The 4 testing sessions each consisted of the standardized warm-up, 1 set of 4 VJs and HJs, a 5-minute rest, 5RM back squat, a 5-minute rest, and the final set of VJs and HJs. Pre- and post-5RM VJ and HJ order was randomly assigned. The results indicated no significant differences occurred between the mean or maximal values for either VJ or HJ as a consequence of the dynamic preload exercise. In addition, the results reflected an inability of subjects to benefit from the repeated exposure to the heavy dynamic preload exercise protocol.     

Effects of electromagnetic field of thermal intensity on the hypophysis-thyroid unit of the neuroendocrine system

Acute 12-minute exposure of laboratory rats to microwaves with specific dose rate (SAR) of 30 W/kg that exceeded a basal metabolism caused a transient response of hyppophysis-thyroid system of compensatory-adaptive character. Prolonged exposure to microwaves of less intensity (SAR = 6 W/kg, which approximately corresponds to basic metabolic rate for these animals) caused insufficiency of the function of thyroid control in a form of primary hypothyroidis.     

Clinical application of a live varicella vaccine (Oka strain) in a hospital

A total of 239 children, including 22 high-risk children and 55 non-high risk diseased children have been immunized with a live varicella vaccine (Oka strain) since June, 1978. No clinical reaction attributable to the vaccine has been observed. Of these children, 87 received emergency vaccination. Of 47 children receiving emergency vaccination because they had been in contact with varicella patients either in hospital, school or a playground, only 5 developed varicella and their symptoms were mild. Of 40 children receiving emergency vaccination because of exposure to varicella in their home, 10 developed mild varicella and 30 were protected. Clinical symptoms of varicella when seen seemed to be due to incomplete protection because the vaccine was given too late rather than to clinical reactions to the vaccine. During follow-up period of 6 to 66 months after vaccination, 8 children showed very mild rashes without fever as the result of exogenous varicella infection.