Androgen receptor content following heavy resistance exercise in men

The purpose of the present investigation was to examine androgen receptor (AR) content in the vastus lateralis following two resistance exercise protocols of different volume. Nine resistance-trained men (age=24.3+/-4.4 years) performed the squat exercise for 1 (SS) and 6 sets (MS) of 10 repetitions in a random, counter-balanced order. Muscle biopsies were performed at baseline, and 1h following each protocol. Blood was collected prior to, immediately following (IP), and every 15 min after each protocol for 1h. No acute elevations in serum total testosterone were observed following SS, whereas significant 16-23% elevations were observed at IP, 15, and 30 min post-exercise following MS. No acute elevations in plasma cortisol were observed following SS, whereas significant 31-49% elevations were observed for MS at IP, 15, and 30 min post-exercise. Androgen receptor content did not change 1h following SS but significantly decreased by 46% following MS. These results demonstrated that a higher volume of resistance exercise resulted in down-regulation of AR content 1h post-exercise. This may have been due to greater protein catabolism associated with the higher level of stress following higher-volume resistance exercise.     

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O(2), 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 +/- 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (< or = 100 micromol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC(50) = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC(50) approximately 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress.     

Bile duct changes in rats reinfected with Clonorchis sinensis

This study describes an evaluation of the sonographic, cholangiographic, pathological, and immunological findings, and the protective effect shown by rats reinfected with Clonorchis sinensis. Eight experimental rat groups were, namely, a normal control, a primary infection control, a reinfection I (reinfection 7 week after treatment following 3-week infection), a reinfection II (reinfection 2 week after treatment following 8-week infection), a reinfection III (exploration of the intrahepatic bile ducts 1 week after reinfection 4 week after treatment following 4-week infection), a superinfection, a secondary infection control, and an infection following immunization group. Sonographic and cholangiographic findings showed moderate or marked dilatation of the bile duct confluence in the primary infection control, reinfection II, and secondary infection control groups. Juvenile worms survived in the intrahepatic bile ducts 1 week after reinfection following treatment in the reinfection III group. It was concluded that reinfecting juvenile worms found during the first week following reinfection failed to survive or grow further. Anatomical, pathophysiological, or immunological changes may induce protection from reinfection in rats.     

Naloxone reduces decrease in ventilation induced by hypoxia in newborn infants

The mechanism responsible for the decrease in ventilation during breathing of low fractional concentration of inspired O2 in the newborn infant is poorly understood. The present study tested the hypothesis that endogenous opiates account for this ventilatory decrease. Eleven healthy newborn infants breathed 15% O2, balance N2 for 5 min following an injection of saline and following an injection of naloxone. Neither injection caused a change in minute ventilation (VE) or ventilatory pattern when the infants were breathing room air. However, the decreased ventilation during hypoxia following naloxone was significantly less than that following saline. VE dropped about 14% following saline but only about 4% following naloxone. However, the adult ventilatory response to hypoxemia, i.e., a relatively sustained increase in VE, was not attained. Naloxone had no influence on the occurrence of periodic breathing during hypoxemia. Thus in the healthy full-term newborn infant, endogenous opiates account only for a part of the decreased ventilation during hypoxemia.     

Effects of ovulation on the conduction and contraction velocities in rabbit oviduct: contrasts between longitudinal and circular muscle

The contraction and electrical conduction velocity of the longitudinal and circular muscle of the oviduct from rabbits in estrus, 24 or 72 h following administration of human chorionic gonadotropin (hCG) or 14 days following castration have been compared. Two populations of conduction and contraction velocities were identified, with the faster velocity being associated with the longitudinal muscle. There was a large overlap between longitudinal and circular contraction, suggesting complex relationships between longitudinal and circular muscle. From the results it appears that during ovum transport the circular velocities increased, with the slowest rates at estrus. The values obtained 72 h following hCG injection most closely resembled those in the castrate group of animals. In the longitudinal orientation, however, the velocities were greater 24 h following hCG injection than at estrus or 72 h following hCG injection, suggesting a complex relationship between both longitudinal and circular muscle of the oviduct following ovulation.     

Inter-male mating-like behavior in the domesticated house musk shrew, Suncus murinus

In the present study, inter-male interaction of the domesticated house musk shrew was observed in detail under laboratory conditions. In most cases, during inter-male interaction, male house musk shrews exhibited a sequence of behavior items including tail-wagging, following, mounting and thrusting. In the minority of cases, males did not progress beyond following. Offensive behavior was not sufficiently violent to cause injury. It appeared that role assignment was decided by contact manner and vocalization. One of fundamental characters of this animal made a start of following, in which one shrew followed another, who touched and then separated. Role assignment (i.e., which male led and which followed) was decided in status battle. Roles were often reversed during following. Following behavior was maintained by 'polite' mutual contact, and the interaction progressed to thrusting in the majority cases. After role assignment, the variation in contact manner decreased. The ratio of time spent in front-and-behind contact to that spent in multi-lateral contact increased when both males commenced following behavior simultaneously. This ratio was maintained until the following male snapped after he finished thrusting. Even if the following male did not reach thrusting, he mounted the preceding male. The pairs who did not reach thrusting repeated following behavior or mounting. In those cases, while one male concentrated on touching the other to maintain following, the other attempted to divert attention from the following behavior. Male shrews were able to reach thrusting irrespective of sex.     

Transverse myelitis following measles vaccination in a rhesus macaque (Macaca mulatta)

A 16-year-old rhesus macaque presented with progressive, ascending quadriparesis following measles vaccination. He was diagnosed with transverse myelitis following MRI, gross necropsy, and histopathology. This is the first report of transverse myelitis in a rhesus macaque following measles vaccination.     

Dexamethasone inhibition and phorbol myristate acetate stimulation of plasminogen activator in human embryonic lung cells

Treatment of human embryonic lung cells with dexamethasone resulted in a decrease in plasminogen activator activity measured in the fibrinolytic assay. The decrease in activity could at least partially be explained by the presence of an inhibitory substance(s) based on the following observations of lysates of dexamethasone-treated vs. control cells: a) an increase in specific activity following subcellular fractionation; b) an increase in fibrinolytic activity following separation by gel electrophoresis; c) an increase in fibrinolytic activity following mild acid-treatment; and d) a decrease in urokinase-directed fibrinolytic activity in mixing experiments. Phorbol myristate acetate increased plasminogen activator activity without affecting the level of inhibitory substance.     

Use of cloprostenol as an abortifacient in the llama (Lama glama)

As part of a larger project investigating the development and heritability of choanal atresia glama), it was necessary to develop a protocol for aborting llamas at various stages of gestation. Twenty-seven animals between 4 and 7 mo of gestation were successfully aborted a total of 53 times following two 250 microg intramuscular injections of cloprostenol at 24 h intervals. Abortion was induced once in 10 animals and multiple times (range 2 to 5) in 17 animals. Twenty-four animals (45.2%) aborted 3 d following the first injection, with 20 animals (37.7%) aborting 4 d post prostaglandin administration. Other animals aborted at 2 d (n=6, 11.3%), 5 d (n=2, 3.8%), and 7 d (n=1, 1.9%) following drug administration. Forty-nine (92.5%) of the abortions occurred following a single series of injections, while 4 animals (7.5%) aborted following a second series of injections. No confirmed pregnant animals failed to abort following the second series of cloprostenol injections. Conception rates in animals rebred 2 to 4 wk following an abortion were comparable to those of untreated animals in the research herd. Unlike the severe hypertension and death that has been reported following dinoprost tromethamine administration in the llama, no adverse reactions were observed in this study following cloprostenol administration. The results demonstrate that llamas can be safely and effectively aborted up to 7 mo of gestation (normal full term gestation = 342 +/- 10 days) without adverse effects on subsequent fertility.     

Disruption of imprinting by memory inhibitors

Several amnestic drugs were administered intracranially to day-old chicks at selected times around a 10-min exposure to an imprinting stimulus. The drugs used were monosodium glutamate, ouabain, cycloheximide and amino-iso-butyrate. The chicks were tested for 10 min in the same apparatus two days later, and the time spent following the stimulu was recorded., The index of memory retention was the difference between the time spent following on test and the time spent following on the initial exposure. When compared with saline-injected control, glutamate administered 5 min before the beginning of the initial exposure was effective in producing a reduction in following times and hence amnesia. Ouabian was effective when injeced before the beginning and immediately after the end of the initial exposure; while cycloheximide was effective when administered as late as 5 min after the initial exposure. The effective times of administration for the drugs to produce a reduction in following times were similar to that observed for amnesia in passive avoidance memory tasks. The increase in following shown by the control chicks was not a developmental effect due to the increae in age on test. Experiments involving a choice of stimuli on test support the invovement of a memoryrelated phenomenon in these experiments.     

Is re-feeding efficiency compromised by prolonged starvation during aestivation in the green striped burrowing frog, Cyclorana alboguttata?

We examined several morphological parameters of the gastrointestinal tract, digesta passage rates, and nutrient assimilation efficiencies of Green-striped Burrowing frogs (Cyclorana alboguttata) following prolonged fasting during three months of aestivation and compared these with frogs that had been continuously fed. Whole animal digesta passage rates were significantly reduced following three months aestivation as a result of a decreased digesta evacuation rate from the stomach. Furthermore, food was selectively retained in the small intestine for an increased time following three months of aestivation. Overall digestibility of food and nitrogen, carbon, and energy extraction efficiencies were not significantly different from control values following three months of aestivation. These findings suggest that C. alboguttata employs reduced digesta passage rates so as to maximize nutrient assimilation efficiency following prolonged food deprivation during aestivation.     

Social contact and hormonal changes predict post-conflict cooperation between friends

Long-term cooperation between individuals necessitates repairing damage arising from inevitable competing interests. How two members of a valuable relationship switch from competing to cooperating constitutes an important problem for any social species. Observations of non-human animals suggest that affiliative contact immediately following a contest facilitates continued cooperation. Behavioral studies further indicate that winners and losers frequently differ in hormonal changes following a competition. We tested the hypothesis that immediate contact with increases in cortisol (and testosterone for men) for winners following competition would facilitate subsequent cooperation between adult same-sex friends. Results show that contact (versus no contact) immediately following competition enhanced subsequent cooperation between female friends. During contact, increases in winner's cortisol for both sexes, and in testosterone for men, predicted future cooperation. Our results suggest two mechanisms that maintain social bonds following competition between established allies.     

Expansion of intestinal stem cells associated with long-term adaptation following ileocecal resection in mice

Sustained increases in mucosal surface area occur in remaining bowel following massive intestinal loss. The mechanisms responsible for expanding and perpetuating this response are not presently understood. We hypothesized that an increase in the number of intestinal stem cells (ISC) occurs following intestinal resection and is an important component of the adaptive response in mice. This was assessed in the jejunum of mice 2-3 days, 4-5 days, 6-7 days, 2 wk, 6 wk, and 16 wk following ileocecal resection (ICR) or sham operation. Changes in ISC following ICR compared with sham resulted in increased crypt fission and were assayed by 1) putative ISC population (SP) by flow cytometry, 2) Musashi-1 immunohistochemistry, and 3) bromodeoxyuridine (BrdU) label retention. Observed early increases in crypt depth and villus height were not sustained 16 wk following operation. In contrast, long-term increases in intestinal caliber and overall number of crypts per circumference appear to account for the enhanced mucosal surface area following ICR. Flow cytometry demonstrated that significant increases in SP cells occur within 2-3 days following resection. By 7 days, ICR resulted in marked increases in crypt fission and Musashi-1 immunohistochemistry staining. Separate label-retention studies confirmed a 20-fold increase in BrdU incorporation 6 wk following ICR, confirming an overall increase in the number of ISC. These studies support that expansion of ISC occurs following ICR, leading to an overall increase number of crypts through a process of fission and intestinal dilation. Understanding the mechanism expanding ISCs may provide important insight into management of intestinal failure.     

Relationship between oxidative phosphorylation and adenine nucleotide translocase activity of two populations of cardiac mitochondria and mechanical recovery of ischemic hearts following reperfusion

The possible relationship of the atractyloside-sensitive adenine nucleotide translocase activity, oxidative phosphorylation, and the recovery of ventricular contractility following reperfusion of the ischemic isolated rat heart was studied. Five minutes of total global ischemia without reperfusion produced a significant depression in adenine nucleotide translocase in subsarcolemmal mitochondria (SLM), whereas a minimum of 10 min ischemia was required to observe a significant depression in interfibrillar mitochondria (IFM). Increasing durations of ischemia resulted in a progressively larger depression in translocase activity, with a maximum depression of approximately 75% seen in both populations following 20 min ischemia. In contrast, oxidative phosphorylation was totally unaffected in either mitochondrial population following up to 20 min of ischemia. We assessed whether translocase activity or oxidative phosphorylation were related to contractile recovery in hearts reperfused following various durations of ischemia. In SLM, translocase activity was further depressed following reperfusion compared with pre-reperfusion ischemic values, whereas with IFM only reperfusion following 5 min ischemia produced a further depression in translocase values. Oxidative phosphorylation rates of SLM and IFM were significantly depressed following reperfusion of ischemic hearts, although SLM exhibited a generally higher sensitivity in this regard. In reperfused hearts, an overall significant relationship was found between oxidative phosphorylation rate and adenine translocase activity as well as between translocase activity and post-reperfusion contractile recovery. These data show that ischemia can produce a significant depression in translocase activity in the absence of any change in oxidative phosphorylation. The results also suggest that the depression in mitochondrial ADP/ATP translocase and subsequent inhibition of oxidative phosphorylation in the reperfused heart may represent one of the important contributory mechanisms involved in cardiac failure and injury during acute ischemia and reperfusion.     

Male pronuclear formation and sperm mitochondria in porcine oocytes following intracytoplasmic injection of pig or mouse sperm

In the present study we determined the chromatin organization and fate of introduced mitochondria in porcine embryos following intracytoplasmic injection of pig or mouse sperm cells. At 3, 6, 9 and 12 h following injection of pig or mouse spermatozoa or isolated sperm heads, the oocytes were fixed and stained with propidium iodide. Between 3 and 6 h following injection, both porcine and murine sperm chromatin developed into pronuclei. The male and female pronuclei were apposed within 12 h in porcine oocytes following sperm injection from either source. We also introduced foreign mitochondria from either mouse or pig sperm midpiece into porcine oocytes following sperm injection. While porcine sperm mitochondria rapidly disappeared from the actively developing porcine oocytes, mouse sperm mitochondria remained in the embryos until the 8-cell stage. These results suggest that pronuclear formation and movement occur between 6 and 12 h following sperm incorporation into the cytoplasm, and that foreign mitochondria are selectively removed in a species-specific manner.     

Cytoskeletal organization following cannabinoid treatment in undifferentiated and differentiated PC12 cells.

Confocal microscopy in association with three-dimensional reconstruction was used to examine the changes in the microtubules and microfilaments following cannabinoid treatment of PC12 cells. Microtubules and microfilaments were disrupted in a dose-dependent manner following treatment with 10-30 microM delta 9-tetrahydrocannabinol (THC). A disruption of microtubules and microfilaments was observed following treatment with 30 microM cannabidiol and cannabinol. The amount of microtubules and microfilaments was reduced in a dose-dependent manner following treatment with 10 and 20 microM THC. Cannabidiol and cannabinol reduced the amount of microtubules and microfilaments; however, the reduction was less than that observed with THC treatment. Following the addition of nerve growth factor, differentiated PC12 cells were generally more sensitive to cannabinoid treatments than undifferentiated cells. The possible mechanisms that may account for the changes in microtubules and microfilaments following cannabinoid treatment are discussed.     

Change in the succinate dehydrogenase activity of peripheral lymphocytes in the rat in early periods following exposure to ionizing radiation

Activity of succinate dehydrogenase (SDH) in peripheral blood lymphocytes of albino mongrel rats was determined during an hour following gamma-irradiation. The highest SDH activity in blood lymphocytes (a 41 per cent increase) was registered 20-30 min following 75 Gy irradiation of the head. With a dose of 20 Gy the SDH response was twice as low. During 1 h following irradiation with a dose of 200 Gy the SDH activity exhibited a 10 per cent decrease.     

Renal vasopressin receptor expression and function in rats following spaceflight.

It has been suggested there is a decreased renal responsiveness to vasopressin following spaceflight and that this may be the mechanism for the increased urine flow that is observed following return to normal gravity. In the present study, we have therefore measured vasopressin receptor expression and activity in kidneys taken from rats 1 and 14 days following spaceflight of 15 days duration. Measurements of renal vasopressin V(2) and V(1a) receptor mRNA expression by quantitative RT-PCR demonstrated little difference at either 1 day or at 14 days following return from space. Evaluation of (3)H-labeled arginine vasopressin binding to membranes prepared from kidneys indicated that the majority of the vasopressin receptors were V(2) receptors. Furthermore, the data suggested that binding to vasopressin V(2) or V(1a) receptors was unaltered at 1 day and 14 days following spaceflight. Similarly, the ability of vasopressin to stimulate adenylate cyclase suggested no change in vasopressin V(2) receptor activity in these animals. These data suggest that, whatever changes in fluid and electrolyte metabolism are observed following spaceflight, they are not mediated by changes in vasopressin receptor number or vasopressin-induced stimulation of adenylate cyclase.     

Stimulation of enhanced CD8 T cell responses following immunization with a hyper-antigen secreting intracytosolic bacterial pathogen

The intracytosolic niche for replication of Listeria monocytogenes (Lm) facilitates delivery of bacteria-derived Ags into the MHC class I pathway for subsequent stimulation of CD8 effector T cells. Using Lm strains that are equivalent for in vivo virulence yet express marked differences in the level of secretion of a protective target Ag, we have evaluated how these specific differences in secretion levels influences the magnitude and effector function of Ag-specific CD8 T cell responses following Lm injection. Immunization with low doses of a hyperantigen-secreting Lm strain stimulated enhanced target-Ag specific CD8 T cell responses compared with the magnitude stimulated following immunization with the same dose of wild-type Lm. The enhanced determinant-specific response was also evident by in vivo CTL activity, increased numbers of memory cells 4 wk following immunization, and enhanced antilisterial protection following a challenge infection. Initiation of antibiotic treatment 24 h following infection with wild-type Lm markedly reduced the magnitude of the effector CD8 T cell response. In contrast, antibiotic treatment initiated 24 h following immunization with the hyperantigen secreting strain of Lm did not impact the frequency of the target-Ag specific CD8 T cells. Thus, immunization with a low dose of a hyperantigen secreting Lm strain, followed by antibiotic treatment to limit the extent of the infection, may represent a safe strategy for the stimulation of enhanced effector CD8 T cell responses to specific Ag by a rLm vaccine.