Effect of longitudinal gravitational loads on the structure of the wall of the vertebral artery]

A single exposure to the greatest endurable gravitation stress causes such changes in the wall of the vertebral artery as division into layers, oedema, vacuolization of smooth muscle cells. Repeated exposure according to a training schedule resulted in reconstruction of the vascular wall (division of the medial sheath of the artery into several muscular layers). Concentration of smooth muscle cells in "layers" increased when training was after a "cumulative" schedule. Under conditions of increasing cumulative effect the collagenization of the media and dystrophy of the muscular and elastic tissue began. The greatest changes in the arterial wall took place in the upper parts of the vertebral artery at the level of the 2nd and 3d cervical vertebra.     

A biophysical approach to the investigation of physiological processes

It was shown that understanding the mechanism of rhythmic excitation in cells and tissues requires the combination of physiological and biophysical approaches. Systemic studies of changes in the physicochemical characteristics of the object were carried out by a protocol that takes into account the mode of rhythmic excitation and the functional sate of the object being studied. The validity of the approach was proved in studies of rhythmic excitation in somatic nonmyelinic and myelinic nerves, and in model systems. The approach can be used in studies of many physiological processes.     

Nerve endings of the walls of the descendent colon and rectum

Summary Two types of nerve endings in the muscular wall of the descendent colon and rectum are shown in this paper. The first one, is constituted by thick extrinsic fibers ending by neurofibrillar sharpened points which are subdivided in two groups; unlimited endings having its branches placed among the muscular fascicles is one of them (interfascicular nerve endings). The other one belongs to limited endings sited in connective spaces sourrounded by the muscular bundles. The second type of neuromuscular relation is integrated by long and slender fibers. In some cases its origine of a local neuron was prooved by us.Endings in the mucous layer were also found. The Lieberkühn glands have nervous fibers distributing only at its bottom; nervous fibers supply only the upper part of the glands and also the epithelial surface, and an intermediary type of them distributing its branches to the whole width of the mucosae.     

Effect of changes in temperature on the cholesterol and phospholipid ratio in nerve fibers of the frog and squid

The character of changes in molar correlation of cholesterol and phospholipids has been studied at different functional states in frog myelinic nerve and squid nonmyelinic nerve trunk. The correlation cholesterol/phospholipid (C/P) found for both nerves in rest increases at temperature 38 degrees C. The electrical stimulation on the background of higher temperature action leads to unequal shift of C/P: the increase compared with the rest in frog and decrease in squid.     

Lingual innervation in the buffalo]

The lingual and papillary mucosa innervation has been studied in the buffalo by histochemical and immunohistochemical techniques and by gold impregnation method of Ruffini. In lingual mucosa the presence of ganglionic structures has been noticed in which there are numerous cellular bodies and bundles of fibres variously directed. Particularly in the vallate papillae, the papillary stroma contains myelinic and unmyelinated fibres and terminal nerve corpuscles. Along stromal myelinic fibres the presence of the proteins S-100 and NF has been demonstrated.     

Blood supply to osteocutaneous free fibula flap and peroneus longus muscle: prospective anatomic study and clinical applications.

From January of 1998 to December of 1999, a total of 24 fibula free flaps in 24 patients were evaluated in a prospective clinical study. Once the perforators were identified, they were dissected toward the parent vessel and labeled according to type. The soleus and flexor hallucis longus muscles of the fibula were dissected, and the proximal part of the pedicle was reached. Subsequently, the configuration of all muscular branches to the peroneus muscle was studied. The types of skin perforators of the peroneal artery were noted as septocutaneous, musculocutaneous, or septomusculocutaneous. A total of 86 perforators were identified in 24 legs. The average number of perforators per leg was 3.58 +/- 0.71. Among them, 22 were musculocutaneous, 31 were septomusculocutaneous, and were 33 septocutaneous. The septocutaneous branches were significantly more distal than the musculocutaneous and septomusculocutaneous perforators. Eight perforators were identified 25 cm distal from the fibular head and six were identified at 15 cm. Five perforators were then identified at each distance of 8, 12, 19, and 22 cm distal from the fibular head. The total number of muscular branches to the peroneus longus was 62, with an average of 2.58 +/- 0.45. Most muscular branches were found between 8 and 16 cm distal to the fibular head. Nine branches were identified at 13 cm distal to the fibular head, eight at 9 cm, and seven at 12 cm. The number of dominant branches with the largest diameter was seven at 13 cm distal from the fibular head, five at 12 cm, five at 16 cm, and two at 11 cm. In summary, when designing an osteocutaneous free fibula flap 10 to 20 cm from the fibular head, it is recommended that a soleus and flexor hallucis longus muscle cuff be included to incorporate these perforators. In contrast, when designing a flap 20 to 30 cm from the fibular head, it is possible to elevate the flap without incorporating the soleus or flexor hallucis muscles.     

Vascular anatomy of the forearm muscles: a study of 50 dissections

This anatomic study is based on 50 adult cadaver upper extremities. The general disposition of the forearm arteries and muscles and the main anatomic variations encountered are specified. Constant existence of an "anterior oblique artery" satellite of the pronator teres was established. The median nerve artery was principally dedicated to the flexor digitorum superficialis and participated appreciably in the constitution of palmar arches in only one case. A supernumerary intermedial radial muscle was found only in two cases. The abductor pollicis longus and extensor pollicis brevis appeared as a single muscular and vascular unit in 84 percent of cases. All the arteries destined for muscles were reckoned whatever their caliber might be. Despite its limitations, this study confirms the very great number of the forearm muscular pedicles. Each forearm contained an average of 264 muscular vascular pedicles. The systematization of the origins and destinations of the 13,158 muscular pedicles is described in a numbered manner for each of the 20 normal forearm muscles and for each of the 12 studied arterial segments. The pronator teres was likely to be supplied by all the anterior arteries of the upper limb. The flexor carpi radialis had one or two dominant pedicles originated from the recurrens ulnaris anterior, recurrens ulnaris, or ulnaris-interossea communis arteries, and many transversal branches originated from the radial artery. The flexor carpi ulnaris was supplied in its proximal third by the recurrens ulnaris posterior artery and in its distal two-thirds by many branches of ulnar artery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Peripheral nervous control of cold-induced reduction in the respiratory quotient of the rat

Cold-exposed rats show a reduction in the respiratory quotient which is indicative of a relative shift from carbohydrates to lipids as substrates for oxidative metabolism. In the present study, the effects of food deprivation and cold exposure on the respiratory quotient were observed. In addition, the involvement of the three main branches of the peripheral nervous system (sympathetic, parasympathetic, and somatic) was investigated by means of synaptic blockade with propranolol, atropine, and quinine, respectively. Both propranolol and quinine blocked the cold-induced decrease in respiratory quotient and increase in heat production, whereas atropine had only minor and very brief effects. It is concluded that both the sympathetic and somatic branches are involved in the metabolic changes associated with cold-induced thermogenesis and that the increase in metabolic heat production involves a shift from carbohydrate to lipid utilization irrespective of which of the two branches is activated.     

Photosynthetic acclimation of the liana Stigmaphyllon lindenianum to light changes in a tropical dry forest canopy

Tropical plant canopies show abrupt changes in light conditions across small differences in spatial and temporal scales. Given the canopy light heterogeneity, plants in this stratum should express a high degree of plasticity, both in space (allocation to plant modules as a function of opportunity for resource access) and time (photosynthetic adjustment to temporal changes in the local environment). Using a construction crane for canopy access, we studied light acclimation of the liana Stigmaphyllon lindenianum to sun and shade environments in a tropical dry forest in Panama during the wet season. Measured branches were randomly distributed in one of four light sequences: high- to low-light branches started the experiment under sun and were transferred to shade during the second part of the experiment; low- to high-light branches (LH) were exposed to the opposite sequence of light treatments; and high-light and low-light controls , which were exposed only to sun and shade environments, respectively, throughout the experiment. Shade branches were set inside enclosures wrapped in 63% greenhouse shade cloth. After 2 months, we transferred experimental branches to opposite light conditions by relocating the enclosures. Leaf mortality was considerably higher under shade, both before and after the transfer. LH branches reversed the pattern of mortality by increasing new leaf production after the transfer. Rates of photosynthesis at light saturation, light compensation points, and dark respiration rates of transferred branches matched those of controls for the new light treatment, indicating rapid photochemical acclimation. The post-expansion acclimation of sun and shade foliage occurred with little modification of leaf structure. High photosynthetic plasticity was reflected in an almost immediate ability to respond to significant changes in light. This response did not depend on the initial light environment, but was determined by exposure to new light conditions. Stigmaphyllon responded rapidly to light changes through the functional adjustment of already expanded foliage and an increase in leaf production in places with high opportunity for carbon gain. Received: 24 April 1998 / Accepted: 11 May 1999     

The distribution of molecular species of phosphatidylinositol in ox brain and its subcellular fractions

1. The phosphatidylinositol content of white and grey matter of ox cerebral hemispheres did not differ. The phosphatidylinositol from grey matter was slightly enriched in palmitic acid and arachidonic acid, and that from white matter was enriched in eicosatrienoic (C(20:3)) acid. These regional differences were apparently due to the greater content of myelin in the white matter, since the same tendencies were observed when combined myelinic and non-myelinic subcellular fractions prepared from the cerebral hemispheres were compared. 2. Purified phosphatidylinositol was converted into its triacetylated methylated derivative and resolved to its molecular species by t.l.c. on AgNO(3)-impregnated silica gel. The tetraenoic molecular species was predominant in phosphatidylinositol from ox cerebral hemispheres, and this feature characterized all the phosphatidylinositol samples extracted from its regions or subcellular fractions. The grey matter was more enriched in the tetraenoic species and the white matter in the trienoic species. 3. The molecular-species composition of phosphatidylinositol from the subcellular fractions of ox cerebral hemispheres was studied. The trienoic species constituted nearly one-fifth of the phosphatidylinositol from two myelinic fractions. ;Large myelin' was more enriched in this species than was ;small myelin'. Both fractions also contained greater concentrations of the dienoic species than the non-myelinic subcellular fractions. The latter fractions, one containing nuclei and the other nerve endings plus mitochondria, were enriched in the monoenoic and tetraenoic species of phosphatidylinositol. The post-mitochondrial supernatant exhibited a pattern of distribution of phosphatidylinositol species intermediate between the myelinic and non-myelinic fractions.     

Acetic acid induces a programmed cell death process in the food spoilage yeast Zygosaccharomyces bailii

Here we show that 320-800 mM acetic acid induces in Zygosaccharomyces bailii a programmed cell death (PCD) process that is inhibited by cycloheximide, is accompanied by structural and biochemical alterations typical of apoptosis, and occurs in cells with preserved mitochondrial and plasma membrane integrity (as revealed by rhodamine 123 (Rh123) and propidium iodide (PI) staining, respectively). Mitochondrial ultrastructural changes, namely decrease of the cristae number, formation of myelinic bodies and swelling were also seen. Exposure to acetic acid above 800 mM resulted in killing by necrosis. The occurrence of an acetic acid-induced active cell death process in Z. bailii reinforces the concept of a physiological role of the PCD in the normal yeast life cycle.     

Callosal transfer of impulses originating from superficial and deep nerves of the cat forelimb.

1. Experiments were performed in 18 chloralose-anaesthetized, curarized cats in order to study the callosal transfer of somatic information originated in exteroceptive and proprioceptive receptors. Several cutaneous and deep nerves of the forelimb were prepared and stimulated with graded intensities, so as to activate selectively afferent fibres pertaining to the different groups of Lloyd's classification. Simultaneous records were taken (and averaged on-line by means of a multichannel analyzer) from the distal end of a cut dorsal rootlet (C7-C8), from the cerebral cortex (SI, SII or area 3a, according to the experiment) and from the somesthetic callosal region (SCR). 2. The low-threshold afferent fibres (Group II) of cutaneous origin were found to have a wide projection to the SCR, with the maximal density in its middle portion. Some of the fastest corticocallosal impulses are relayed monosynaptically at cortical level. Plots of the amplitude of cortical and callosal responses as a function of stimulus strength showed that both central responses have the same threshold and exhibit a parallel, sharply-rising amplitude increase, thus suggesting that the cortico-callosal re-transmission system for afferent impulses of cutaneous origin is very powerful in nature. Impulses elicited in afferent fibres of higher threshold (Group III) do not enhance the cortical and callosal positive waves provoked by Group II afferent volleys. 3. Afferent fibres of deep origin were also found to send a wide projection to the SCR, although less substantial than that of cutaneous fibres. Stimulation of the deep radial nerve elicited mass responses in the whole SCR, provided the strength of stimuli was high enough to engage the Group II fibres. Only in the central portion of the SCR were small potentials recorded in response to pure Group I volleys of DRN. Experiments performed with selective stimulation of pure muscular branches of forelimb deep nerves as well as of articular and mixed (muscular and articular) branches gave evidence making it possible to ascertain the origin of deep afferent fibres projecting to the SCR. Stimulation of the forelimb muscular branches with strength provoking full activation of Group I afferent and additional engagement of those of Group II, did not provoke mass responses in the whole extent of the SCR. In order to obtain callosal potentials upon stimulation of pure muscular nerves, it was necessary to increase the stimulus strength at or above the threshold for Group III fibres. On the contrary, the same callosal foci unresponsive to Group I and II muscular afferent volleys exhibited clear-cut responses to stimulation of the lowest-threshold Group I and/or Group II afferents of articular and mixed nerves. From the results it might be inferred that only proprioceptive information originating from articular receptors and from extrafusal muscular afferents has access to the callosal interhemispheric transfer.     

Exposure to Asulox inhibits the growth of mosses

Asulox is a herbicide used to control bracken. Its effects on mosses were investigated to ascertain whether exposure proved as detrimental as found in parallel studies on pteridophytes. Mature gametophytes of 18 mosses were exposed to a range of concentrations of Asulox under standard conditions and the effects on growth monitored. Plants were cut to a standard length, exposed to Asulox solution for 24 h, grown for 3 weeks and total elongation (main stem and branches) measured. EC50 values were calculated and species ranked according to sensitivity. The effects of exposure on total elongation were compared with those on main stem elongation alone. Under the conditions tested, the total elongation of all species was inhibited after exposure to Asulox. The amount of elongation observed after exposure was different for different species and inhibition of elongation occurred at different exposure concentrations. A single regression equation was not adequate to describe the dose response curves of all species tested. An ability to produce secondary branches may confer increased tolerance to Asulox exposure. It is concluded that mosses suffer detrimental effects after exposure to Asulox at concentrations similar to those that affect fern gametophytes such as bracken.     

人脊髓前角运动神经元190KD蛋白的初步研究

本研究采用ＳＤＳ凝胶电泳方法从人脊神经前根中分离出人脊髓前角运动神经元特有的蛋白—１９０ＫＤ。将该蛋白作为抗原,免疫ＢＡＬＢ／ｃ小鼠,经杂交瘤技术,获得了抗１９０ＫＤ蛋白的单克隆抗体。免疫细胞化学检测表明,１９０ＫＤ单抗与脊髓灰质前角神经元、前根及肌支发生阳性反应。实验结果提示,１９０ＫＤ蛋白分布在脊髓运动神经元胞体及脊神经的前根和肌支纤维中。     

Compositional changes of the muscular layers of the stomach with aging

To elucidate compositional changes of the stomach with aging, the authors investigated age-related changes of the elements and relationships among the elements in the muscular layers of the pylorus, cardia, lesser curvature, and greater curvature by inductively coupled plasma-atomic emission spectrometry. After ordinary dissection by medical students, the pylori, cardias, lesser curvatures, and greater curvatures were removed from the subjects, consisting of 19 men and 1 woman, ranging in age from 65 to 95 yr. The muscular layers were isolated and the element contents were determined.The calcium content increased progressively with aging in the muscular layers of the pylorus, cardia, and lesser curvature, whereas it tended to increase in the muscular layer of the greater curvature with aging. Regarding sulfur, the content increased significantly in the muscular layer of the pylorus with aging, but not significantly in the muscular layers of the cardia, lesser curvature, and greater curvature with aging.Regarding the relationships among the elements, significant direct correlations were found among calcium, phosphorus, sulfur, and magnesium in both the muscular layers of the pylori and cardias, with some exceptions.     

The effects of acute heat exposure on muscular strength,muscular endurance,and muscular power in the euhydrated athlete

The purpose of this study was to determine the effects of acute heat exposure upon muscular strength, muscular endurance, and muscular power in euhydrated athletes. Ten healthy, weight-trained men (average age = 23.0 +/- 4.0 years) volunteered for this investigation. Subjects were randomized to normothermic (22.5 degrees C, 65% relative humidity [RH]) or hyperthermic (65-75 degrees C, 15% RH) condition for 30 minutes. Results indicated that all subjects experienced significant (p < 0.05) hemodynamic stress because of the 30 minutes of heat exposure (blood pressure [BP](rest) 124/78 mm Hg to BP(postsauna) 148/60 mm Hg, heart rate [HR](rest) 64 b.min(-1) to HR(postsauna) 122 b.min(-1)). Oral and tympanic temperature measurements correlated strongly (r(2) = 0.904) and increased by 2.48 and 2.71 degrees C, respectively, during sauna exposure. One repetition maximum (1RM) bench press strength did not differ between the 2 conditions, whereas 1RM leg press strength was significantly decreased (p < 0.05) after the hyperthermic protocol. Subjects' muscular endurance decreased significantly (p < 0.05) in both the leg press (29.2%) and bench press (15.8%) after the sauna exposure. In contrast, muscular power (vertical jump) increased significantly (3.1%, p < 0.5) after acute heat exposure. In agreement with previous studies, we concluded that acute heat exposure is detrimental to muscular endurance; however, the areas of strength and power are far less unequivocal.     

Real-time measurement of free Ca2+ changes in CNS myelin by two-photon microscopy

Here we describe a technique for measuring changes in Ca2+ in the cytosolic domain of mature compact myelin of live axons in the central nervous system (CNS). We label the myelin sheath of optic nerve and dorsal column axons by using the Ca2+ indicator X-rhod-1 coupled with DiOC6(3) to produce bright myelin counterstaining, thereby providing unambiguous identification of the myelin sheath for analysis of two-photon excited fluorescence. We present evidence for localization of the Ca2+ reporter to the cytosolic domain of myelin, obtained by using fluorescence lifetime, spectral measurements and Mn2+ quenching. Chemical ischemia increased myelinic X-rhod-1 fluorescence (approximately 50% after 30 min) in a manner dependent on extracellular Ca2+. Inhibiting Na+-dependent glutamate transporters (with TBOA) or glycine transporters (with sarcosine and ALX-1393) reduced the ischemia-induced increase in Ca2+. We show that myelinic N-methyl-D-aspartate (NMDA) receptors are activated by the two conventional coagonists glutamate and glycine, which are released by specific transporters under conditions of cellular Na+ loading and depolarization in injured white matter. This new technique facilitates detailed studies of living myelin, a vital component of the mammalian CNS.     

A comparison of cluster-based exposure variation and exposure variation analysis to detect muscular adaptation in the shoulder joint to subsequent sessions of eccentric exercise during computer work

The aim of this study was to compare the capability of a cluster-based exposure variation (C-EVA) with a conventional exposure variation analysis (EVA) to detect muscular adaptation in the shoulder joint to subsequent sessions of eccentric exercise (ECC). Eleven healthy subjects performed work with a computer mouse for 10 min at three instants, i.e., before, immediately after, and 24 h after ECC. The subjects repeated an identical procedure one week after the first session. Surface electromyography was recorded from descending and ascending part of the trapezius, deltoid anterior, and serratus anterior muscles. EVA and C-EVA were performed and their marginal distributions were extracted. A principal component analysis was applied to the marginal distributions of both EVA and C-EVA. Principal component difference was computed by subtraction of the corresponding principal components before the ECC from immediately after and 24 h after the ECC. The first component extracted from C-EVA revealed an interactive effect between the sessions of ECC and instants whereas this effect was absent using the conventional EVA. The current study highlights the importance of a multivariate approach to analyze the potentially important changes in muscular activity in response to the repeated bout effect.     

Heart and the peritoneal cover of the gut sinus in the polychaete Arenicola marina: an ultrastructural and autoradiographic study

To elucidate the cellular mechanism underlying the growth of the peritoneal cover of the gut sinus and the heart in the polychaete Arenicola marina, cellular organization of these structures and proliferative potential of their cells were investigated using electron microscopy and electron microscopic autoradiography. Arenicola has a pair of dorsolaterally situated hearts connected to the gut sinus via a short duct and composed of two muscular layers separated by a layer of the extracellular matrix (ECM). The peritoneal cover of the gut sinus and the outer muscular layer of the heart present a myoepithelial layer resting on the ECM. The inner muscular layer of the heart is composed of myofibril-containing cells lacking well-defined polarity in arrangement of organelles. However, their persistent connection to branches of the ECM and the adherens-like intercellular junctions allow for considering the inner layer a modified myoepithelium. In the peritoneal cover of the gut sinus and in both myoepithelial layers of the heart, noncontractile epithelial cells have been observed. As determined by thymidine labeling, these epithelial cells are capable of DNA synthesis, while myoepithelial cells are not. Some suggestions are made about the myogenic nature of the epithelial cells in the investigated structures of A. marina.     

Effect of ultrasound on the formation of arterial and lymphatic collaterals in the rat pelvic extremities]

Pronounced morphological alterations combined with destruction of muscular tissue make their appearance in intact arterial and lymphatic bed of pelvic extremities in rats after treatment with ultrasound of high intensity. Ultrasound of low intensity failed to cause morphological changes either in the arterial or the lymphatic bed of extremities. A course of exposure of injured arterial and lymphatic bed of rat's pelvic extremities to ultrasound of small intensity considerably accelerated processes of formation of the arterial and lymphatic collaterals.