Spinal vasomotor reflex and Cushing response

A spinal vasomotor reflex that resembles the Cushing response (CR) can be evoked also by isolated intraspinal hypertension. The intensity of the spinal vasomotor reflex (SVR) depends primarily on the length of the isolated spinal cord, i.e., on the total vegetative elements that participate in this mechanism. The vasopressor effect produced by isolated intraspinal hypertension may be the consequence of ischaemia of the spinal vegetative structures. Cur data suggest that in the case of increased intracranial pressure, when craniospinal connections are free and there is no impaction, the CR is due not only the vasomotor centre in the brain stem, but also to spinal vegetative structures.     

External rotational injury of tha ankle joint with displacement of the talus

The mechanism of second-degree external rotational injury of the ankle, with fracture of the lower end of the fibula, is discussed with reference to experiments on an anatomical model. It is concluded that with this type of injury there is lateral displacement of the talus because the deltoid ligament is ruptured, but there is no diastasis of the inferior tibiofibular syndesmosis. The results of conservative treatment of 10 patients with second-degree external rotational injury of tha ankle are reviewed.     

鼓风机静叶角度电位移指示的设计应用

本文详细介绍了包钢热电厂4^#汽轮鼓风机静叶角度,由原机械指针式改为位移电涡流传感式的设计、应用分析。该设计较好地解决了运行中的鼓风机因不能及时掌握静叶角度信息而给生产带来不便因素的问题。     

Changes in the rabbit temporomandibular joint associated with posterior displacement of the mandible

We report a detailed evolutionary study of the RNase P- and RNase MRP- associated RNAs. The analyses were performed on all the available complete sequences of RNase MRP (vertebrates, yeast, plant), nuclear RNase P (vertebrates, yeast), and mitochondrial RNase P (yeast) RNAs. For the first time the phylogenetic distance between these sequences and the nucleotide substitution rates have been quantitatively measured.The analyses were performed by considering the optimal multiple alignments obtained mostly by maximizing similarity between primary sequences. RNase P RNA and MRP RNA display evolutionary dynamics following the molecular clock. Both have similar rates and evolve about one order of magnitude faster than the corresponding small rRNA sequences which have been, so far, the most common gene markers used for phylogeny. However, small rRNAs evolve too slowly to solve close phylogenetic relationships such as those between mammals. The quicker rate of RNase P and MRP RNA allowed us to assess phylogenetic relationships between mammals and other vertebrate species and yeast strains. The phylogenetic data obtained with yeasts perfectly agree with those obtained by functional assays, thus demonstrating the potential offered by this approach for laboratory experiments.     

Effects of experience on stimulus-produced reflex inhibition in the rat.

Notes that acoustic-startle behavior in the rat is inhibited by changes in the auditory and visual environment which immediately precede reflex elicitation. A series of 7 experiments was conducted with 165 male Holtzman albino rats which established that this effect was not present in the naive S unless the preliminary stimulus was a relatively intense noise burst. With visual stimuli and moderate auditory stimuli the requisite condition for the production of reflex inhibition was that the S should have experienced the eliciting stimulus. Exposures to the to-be-inhibitory stimulus or to a conjunction of this stimulus and the eliciting stimulus were not necessary. Once established, the inhibitory effect was not degraded by week-long rest periods nor by "unreinforced" exposures to the inhibitory stimulus. It is conjectured that the experiential effect may reflect some increase in a nonspecific state of alertness or arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of heating with ultrasound on knee joint displacement

The effect of prostaglandin E2 (PGE2) on the activity-related expression of the proto-oncogene c-fos in specific populations of enteric neurons was investigated. Segments of guinea-pig ileum were incubated in vitro in the presence or absence of PGE2, and whole mounts of the myenteric and submucosal plexus were prepared for immunocytochemical localization of Fos, VIP and NPY. Control tissues exhibited a low number of Fos-immunoreactive (Fos-IR) neurons (7 +/- 2% of total). Incubation of the tissues with 10-1000 nM PGE2 for 30 min caused a concentration-dependent increase in Fos-IR submucosal neurons (maximum at 100 nM; 39 +/- 6%), which was not inhibited by TTX. PGE2 did not evoke an increase in Fos-IR myenteric neurons. In double labeling experiments, Fos colocalized exclusively with VIP in the submucosal plexus, and not with NPY. Exposure of stripped segments of guinea pig ileum in Ussing chambers to 100 nM PGE2 evoked an increase in short circuit current (20 +/- 7 microA/cm2), of which the initial rapid phase could be abolished by TTX, and not by atropine and hexamethonium. It is concluded that PGE2 can activate VIP non-cholinergic secretomotor neurons.     

Vasopressin response and terbutaline inhibition of the uterus

A study of the effects of 8-lysine vasopressin (LVP) and its long-acting analogue N-a-triglycyl-8-lysine vasopressin (TGVP) on the myometrium and vasculature of the normal human nonpregnant uterus was undertaken. The results suggest that the vasopressins decrease local endometrial blood flow both directly by effects on the uterine vascular bed, and indirectly by increasing myometrial activity. The effects in vivo can be effectively counteracted by beta2 receptor stimulation.     

Habituation of prepulse inhibition of the startle reflex using an auditory prepulse close to background noise.

This study examined whether prepulse inhibition habituates with repeated presentation of the prepulse alone. Prepulse inhibition was determined by measuring the decrement in the startle response when the acoustic startle-eliciting stimulus was preceded by an auditory prepulse. Rats received repetitive exposures of the same auditory prepulse alone (experimental condition) and of a visual prepulse alone (control condition). To reduce habituation of startle itself and the possible dishabituating influence the startle stimulus might have on habituation of prepulse inhibition, startle stimulus presentations were infrequently interspersed among a much larger number of prepulse-alone presentations. Stimulus-specific habituation of prepulse inhibition occurred using an auditory prepulse 2.5 dB, but not 13 dB, above background noise. Implications are discussed for the role of prepulse inhibition in sensory gating. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Teratogen-mediated inhibition of target tissue response to Shh signaling

Veratrum alkaloids and distal inhibitors of cholesterol biosynthesis have been studied for more than 30 years as potent teratogens capable of inducing cyclopia and other birth defects. Here, it is shown that these compounds specifically block the Sonic hedgehog (Shh) signaling pathway. These teratogens did not prevent the sterol modification of Shh during autoprocessing but rather inhibited the response of target tissues to Shh, possibly acting through the sterol sensing domain within the Patched protein regulator of Shh response.     

Maturation curve of the ultrasonographic alpha angle according to Graf's untreated hip joint in the first year of life

In addition to Graf's classification into different hip-types a maturation-curve of the sonographic alpha-angle was established in order to optimize the differentiation between mature hip joints and those ones which need follow-up and those ones which need treatment at any time within the first year of life. The results obtained are confirming our present knowledge about the spontaneous maturation of physiologically immature hip joints: The mean-value of the alpha-angle crosses the 60 degrees-borderline at about the age of two months, then reaches an about 64 degrees-level at about four months. This 64-degrees-level is more or less unchanged up to the end of the first year of life.     

Selective inhibition of the monosynaptic spinal reflex by a series of hydroxylated alkylaminoindans

5-Hydroxy-2-piperidino-4,5,6,7-tetrahydroindan (5) and a number of related tetrahydro and dihydro compounds were prepared by selective mono- and dihydroxylation of the dihydro products from the Birch reduction of various alkylaminoalkylindans, tetralins, benzenes, and isoindolines. Some of these compounds showed a remarkably selective inhibition of monosynatpic spinal reflex in the segmental cat preparation.     

Stimulus-produced reflex inhibition in the rat during induction of and recovery from barbiturate anesthesia.

Reported 3 experiments which show that the inhibitory effect of a preliminary stimulus on the acoustic startle reflex was disrupted during the induction of sodium pentobarbital (40 mg/kg) in a total of 50 male Holtzman rats. In Exp I (n = 35) and II (n = 8), Ss were injected with the barbiturate, and a startle stimulus was presented either alone or preceded by a white noise burst. Results show that (a) stimulus inhibition was present immediately after injection, (b) was lost during a phase of hyperreactivity which accompanied induction of the anesthesia, and (c) recovered as reactivity diminished in the anesthetic state. Exp III showed that inhibition recovered during an intervening stage prior to complete areflexia and that this recovery revealed that the earlier and later inhibitory failure cannot be ascribed to a drug-dependent degradation in a hypothetical inhibitory system. It was suggested that the expression of reflex inhibition depends on the balanced interplay of excitatory and inhibitory processes which are differentially sensitive to drug intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relaxation training and opiod inhibition of blood pressure response to stress.

The present study was designed to determine the role of endogenous opioid mechanisms in the circulatory effects of relaxation training. Opioid mechanisms were assessed by examination of the effects of opioid receptor blockade with naltrexone on acute cardiovascular reactivity to laboratory stress before and after relaxation training. 32 young men with mildly elevated casual arterial pressure were recruited for placebo-controlled naltrexone stress tests and relaxation training. The results indicated that relaxation training significantly reduced the diastolic pressure response to mental arithmetic stress. Opioid receptor blockade with naltrexone antagonized the effects of relaxation training. These findings suggest that some of the physiological effects of relaxation training are mediated by augmentation of inhibitory opioid mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological response of Saccharomyces cerevisiae to 15-azasterol-mediated growth inhibition

We studied 15-aza-24-methylene-8,14-cholestadiene-3 beta-ol (15-azasterol) inhibition of Saccharomyces cerevisiae growth. Exposure to sublethal concentrations of this drug caused S. cerevisiae cells to undergo a transient period of inhibition at midlog phase. During growth inhibition the turbidity of each culture remained constant, as did the total cell number. Although the proportion of viable cells in cultures decreased from 90 to 12% during inhibition, methylene blue staining showed that less than 40% of the cells underwent metabolic inactivation. We monitored adenosine triphosphate levels throughout the inhibition cycle, and these levels followed kinetics identical to cell growth kinetics. After overcoming inhibition, cellular lipid extracts revealed the presence of a modified form of 15-azasterol. It appeared that the yeast cells were able to overcome 15-azasterol inhibition by an inactivating transmethylation reaction involving S-adenosylmethionine.     

Voluntary and involuntary access to autobiographical memory

Involuntary autobiographical memories recorded in a diary study are compared to voluntary autobiographical memories retrieved in response to verbal cues in a laboratory. The verbal cues were generated to be comparable to the cues that were found to elicit the involuntary memories. The findings demonstrate that voluntary and involuntary retrieval may access different samples of autobiographical memories. The voluntary memories were (1) less specific, (2) more frequently rehearsed, and (3) less emotionally positive than the involuntary memories. A reanalysis of the diary study examined conditions of involuntary retrieval. The memories occurred most frequently when attention was diffuse. They were typically triggered by environmental cues matching central features of the remembered event. The findings are discussed in relation to current models of autobiographical memory.     

Proteoglycan expression in the rat temporomandibular joint in response to unilateral bite raise

We report the development of a novel time-resolved fluorescence immunoassay utilizing two different assay strategies for the simultaneous measurement of estrone-3-glucuronide (EG) and pregnanediol-3alpha-glucuronide (PG) in samples of early morning urine (EMU). The method for the measurement of EG involves the use of a labeled anti-idiotype as a surrogate antigen, whereas the other method (for the measurement of PG) is a regular competitive immunoassay using a labeled antigen. In addition, the procedure uses different lanthanide chelates as labels to monitor ovarian function in women. After washing the streptavidin-coated plate, we added 10 microL of undiluted urine or mixed standard to the coated wells, followed by the addition of 100 microL of assay buffer containing the labeled reactants (i.e., europium-labeled PG and samarium-labeled anti-idiotype recognizing the binding site of the antibody to EG). Subsequently, we added 100 microL of assay buffer containing the two biotinylated specific monoclonal anti-steroid glucuronide antibodies. After incubation for 1 h on a shaker at room temperature, we washed the plate and added 200 microL of enhancement solution to each well. We measured europium and samarium fluorescence, using a gated plate fluorometer with appropriate emission filters. The method demonstrates appropriate sensitivity and precision (all CVs, 5-8%) across the relevant working ranges for each analyte. The technique has been applied to serial EMUs collected from women with normal and stimulated menstrual cycles.     

Effect of antagonistic contractions on the reflex response of a bifunctional muscle

With reference to the concept that contraction of a muscle can be inhibited by contraction of its antagonists, the excitability of a bifunctional muscle, the soleus (plantarflexor and adductor) was studied during voluntary isometric contractions of the abductors in man. For this purpose, the soleus monosynaptic stretch reflex (MSR) was solicited by means of quick-release dorsiflexion movements which also induce inactivation of the tibialis anterior (unloading reflex). When different initial torques of dorsiflexion were developed (reference conditions) the amplitude of the soleus MSR was found to be related linearly to the maximal value of angular acceleration. When an abduction torque was superimposed (combined efforts), the soleus response was always depressed, but no significant reinforcement of this inhibition was observed when the abduction torque increased. From present results, and from classical data concerning reciprocal inhibition between soleus and tibialis anterior, it is concluded that the MSR of a bifunctional muscle is depressed when the antagonists of either one of its functions are voluntarily activated.     

Cyclooxygenase inhibition potentiates the renal vascular response to endothelin-1 in humans

Vascular endothelin-receptor stimulation results in vasoconstriction and concomitant production of the vasodilators prostaglandin I2 and nitric oxide. The vascular effects of cyclooxygenase (COx) blockade (diclofenac intravenously) and the subsequent vasoconstrictor response to endothelin-1 (ET-1) infusion 30 min after diclofenac were studied in healthy men. With COx blockade, cardiac output (7%) and splanchnic (14%) and renal (12%) blood flows fell (all P < 0.001). Splanchnic blood flow returned to basal value within 30 min. Mean arterial blood pressure increased (4%, P < 0.001). Splanchnic glucose output fell (22%, P < 0.01). Subsequent ET-1 infusion caused, compared with previous ET-1 infusion without COx blockade (G. Ahlborg, E. Weitzberg, and J. M. Lundberg. J. Appl. Physiol. 77: 121-126, 1994; E. Weitzberg, G. Ahlborg, and J. M. Lundberg. Biochem. Biophys. Res. Commun. 180: 1298-1303, 1991; E. Weitzberg, G. Ahlborg, and J. M. Lundberg. Clin. Physiol. (Colch.) 13: 653-662, 1993), the same increase in mean arterial blood pressure (4%), decreases in cardiac output (13%) and splanchnic blood flow (38%), but no significant change in splanchnic glucose output. Renal blood flow reduction was potentiated (33 +/- 3 vs. 23 +/- 2%, P < 0.02), with a total reduction corresponding to 43 +/- 3% (P < 0.01 vs. 23 +/- 3%). We conclude that COx inhibition induces renal and splanchnic vasoconstriction. The selectively increased renal vascular responsiveness to ET-1 emphasizes the importance of endogenous arachidonic acid metabolites (i.e., prostaglandin I2) to counteract ET-1-mediated renal vasoconstriction.