Human sympathetic nerve activity to glabrous skin does not increase during simulated diving

In humans, cardiovascular adjustment to simulated diving causes a marked increase in sympathetic outflow to intramuscular vessels and muscle vasoconstriction. Skin vasoconstriction in the hand also occurs during diving in humans. Skin nerve sympathetic activity (SSA), containing vasoconstrictor signals to glabrous skin, unexpectedly was reduced during diving in a previous study of SSA recorded in the peroneal nerve. SSA was recorded by microneurography in the median nerve in 13 healthy volunteers during simulated diving. Skin blood flow in the hand and one finger was monitored. The typical SSA response, irrespective of duration of diving and water temperature, was an increase during the control period immediately prior to immersion of the face and a sudden reduction of SSA when the face was immersed. The increase in SSA preceding the dive was accompanied by vasoconstriction, which continued during the dive, but re-dilation regularly occurred before the end of the dive. Inhibition of SSA was not total. Mental arithmetic during diving evoked strong bursts of SSA, similar to those seen normally during mental stress. It is concluded that the true response of SSA to simulated diving is an inhibition of the immediately preceding outflow, in agreement with observations of cutaneous blood flow in animals. The skin vasoconstriction recorded during simulated diving is a consequence of an SSA increase before the procedure, suggested to be a stress response before the forthcoming manoeuvre. The SSA response during simulated diving is the opposite to that of sympathetic outflow to muscle, which emphasizes the diversity of sympathetic regulation of different organ systems.     

Diagnostic sonography of the fetal genitourinary tract

Fetal diagnosis has vastly improved over the last decade. Ultrasound has become the imaging modality of choice. As real-time equipment has improved technologically, the ability to deduce subtle abnormalities has greatly increased. The fetal genitourinary tract may be evaluated for renal dysplasias, anomalies, or obstruction. Points of obstruction and, at times, the exact cause of obstruction may be deduced. Abnormalities of the ureter, bladder, urethra, scrotum, or reproductive system can be detected.     

The influence of muscle-conditioned media on chick embryo brainstem neurons in culture

Brainstem pieces from the trigeminal region of the metencephalic basal plate of 10-day chick embryos were dissociated and cultured in control conditions or in the presence of muscle-conditioned medium (MCM). The MCM was derived from age-matched target tissue relevant to this neuronal region (jaw musculature), from relevant target tissue of an age at which innervation would initially be taking place (4 days), and from nonrelevant target tissue also of an early stage (4-day limb bud). Neuronal survival and differentiation was assessed daily, for 7 days. Survival and differentiation were significantly enhanced by the 4-day jaw MCM compared to both the controls and the cultures grown with 10-day jaw MCM and 4-day limb MCM. These measures in the presence of 10-day jaw MCM and 4-day limb MCM did not differ, but surpassed that seen in control cultures. The results are compared to the more specific responsiveness seen in earlier (2-day) neural tube cultures, and their relationship to in vivo regenerative nerve fiber outgrowth is considered.     

Peptidergic neurons in the snail Helix pomatia: Distribution of neurons in the central and peripheral nervous systems that react with an Antibody raised to the insect neuropeptide,leucokinin I

In this study, antiserum raised against an insect myotropic peptide, leucokinin I (DPAFNSWGamide), was: used for mapping leucokinin-like immunoreactive (LK-LI) neurons in the gastropod mollusc, Helix pomatia. Immunocytochemistry performed on both whole-mounts and cryostat sections demonstrated LK-LI neurons in all ganglia of the central nervous system (CNS), except the visceral ganglion. Altogether about 700 immunolabelled neurons have been found, with nearly one-half (46%) in the cerebral ganglia. A large proportion of the LK-LI neurons have small cell bodies and are likely to be interneurons. The most prominent LK-LI cell group is represented by the entire neuron population of the mesocerebri, which is the major source of a thick fiber bundle system, encircling and innervating the whole CNS. One single LK-LI giant neuron was found, which is located in the left pedal ganglion and is termed GLPdLKC (giant left pedal leucokinin immunoreactive cell). This cell has not been identified previously. The ganglion neuropils are heavily innervated by varicose LK-LI fiber arborizations. Some integrative centers, such as the medullary neuropil of the procerebri, reveal an extreme density of LK-LI innervation. All major peripheral nerves contain a large number of LK-LI axons, and LK-LI innervation is found in the musculature of different peripheral organs (buccal mass, lip, tentacles, oviduct, intestine). Among the peripheral organs investigated, the intestine contains a rich varicose LK-LI network, composed of both intrinsic and extrinsic elements. Radioimmunoassay (RIA) demonstrates a very high content of LK-LI material in Helix ganglion extracts (about 50 pmol/CNS). This is the first report on the occurrence of a substance resembling the myotropic neuropeptide leucokinin I in a phylum outside arthropods. Based on our immunocytochemical observations, a role for leucokinin-like peptides in both central and peripheral regulatory processes in Helix is suggested. According to double-labelling experiments, only a small number of the LK-LI neurons are labelled with an antibody to the vertebrate tachykinin substance P.     

药物不良反应国内文献题录检索系统

本文报道了药物不良反应国内文献题录检索系统的设计原理、功能特点,以输入药名及不良反应类别为例,显示了检索系统操作简便,提供信息及时准确的特点。本系统可从药名、不良反应类别及作者等多方面进行检索,可为查询者提供所需的详细资料,弥补了人工查阅文献的不足。并将继续扩大文献资料库,由题录向电报文体文摘形式转化,以贮存更多的信息。     

颈椎椎体次全切除钛网钉板系统的临床应用

目的探讨颈椎前路椎体次全切除钛网钉板植骨融合的临床效果。方法自2001年3月～2003年3月间应用颈前路椎体次全切除钛网植骨融合及钉板固定治疗颈椎管狭窄性疾病22例，其中4例患者行2椎体次全切除3节椎间隙减压手术。术后观察减压、固定、融合及神经功能恢复情况，并行X线摄片或CT扫描检查。结果患者获6～12个月随访，神经功能得到不同程度改善，无加重情况。椎间隙高度无丢失、无成角，均获得骨性融合。术后3d在颈围领固定下下床活动，4周后可恢复较轻工作。结论此术式可避免传统手术方法的缺点，即不取自体髂骨，融合率高，稳定性好，并减压彻底，疗效好，是一种值得推广的新技术。     

Blood pressure and heart rate in parkinsonian patients with and without wearing-off

Our study aimed to investigate the cardiovascular autonomic regulation related to the wearing-off phenomenon in Parkinson's disease (PD). We measured blood pressure (BP) and heart rate (HR) at rest and during orthostatic test in 16 patients with PD with wearing-off and in 15 patients with PD without wearing-off both before (baseline) and repetitively at 1-h intervals for up to 4 h after the morning PD medication dose.
The patients with wearing-off had fluctuation of BP during the observation period, BP increasing when the motor performance worsened and vice versa. The mean supine BP was at its highest at the baseline measurement (patients with wearing-off, 145 ± 18 mmHg; patients without wearing-off, 138 ± 17 mmHg), fell during the first hour (patients with wearing-off, 119 ± 17 mmHg; patients without wearing-off, 126 ± 18 mmHg), and then rose again toward the end of the observation period (patients with wearing-off, 136 ± 15 mmHg; patients without wearing-off, 138 ± 18 mmHg). This BP change was statistically significant only in PD patients with wearing-off ( P  < 0.001).
In conclusion, BP seems to fluctuate with motor impairment in PD patients with wearing-off. This fluctuation may represent autonomic dysfunction caused by the PD process itself, the effect of PD medication, or both.     

Brain Stem and Cervical Cord Dysraphic Lesions in Iniencephaly

Iniencephaly is a rare, lethal, axial dysraphic malformation complex diagnosed on the basis of three cardinal features: deficiency of the occipital bone, cervicothoracic spinal retroflexion, and rachischisis. The majority of the patients also have various associated viscerae malformations. An iniencephalic female fetus delivered at 35^5/7 weeks of gestation revealed severe anomalies of the central nervous system and the spine: the cerebellar vermis was hypoplastic, the medulla oblongata was flattened and broadened, and the cervical canal was widely patent dorsally. The thoracolumbar spinal cord had a duplicated central canal and lacked a dorsal fissure, representing a minor degree of diastematomyelia. The cervicothoracic spine showed severe bony anomalies including aplasia and fusion of vertebral bodies.     

Electrical responses of the muscularis externa to distension of the isolated guinea-pig distal colon

Abstract Enteric reflex pathways were studied in isolated segments of guinea-pig distal colon by recording the electrical responses to distension from the muscularis externa with suction electrodes. The end of the electrode wire were in the circular muscle and thus the recordings discussed below are deduced to be primarily from this layer. Moreover, intracellular microelectrodes in circular muscle cells and suction electrodes recorded similar events. Spontaneous activity consisted of myogenic slow waves at about 25 min ^-1 and transient biphasic potentials at about 6 min^-1 and 3-sec duration which were dependent on a stimulus from the enteric nervous system as they were blocked by tetrodotoxin (0.5 μM), d-tubocurarine (30 μM) and hexa-methonium (100 μM). Atropine (0.8 μM) blocked the depolarizing part of the biphasic potentials and unmasked transient spontaneous inhibitory junction potentials (IJPs) (～2-sec duration) which appeared to be responsible for the hyperpolarizing part of the biphasic potential. Three different responses were observed at sites oral to distension of the colon: a transient depolarizing response that was cholinergic (blocked by atropine (0.8 μM); ascending cholinergic excitation) and, after atropine, a transient IJP (ascending inhibition) which was followed by a transient non-cholinergic depolarizaton (ascending non-cholinergic excitation) that was sometimes followed by several cycles of slow wave activity. The oral responses to anal distension were also blocked by the nicotinic antagonists and were similar to the neurogenic spontaneous events, which also appeared to originate from activity in ascending nervous pathways. Four different responses were observed following distension of the oral end of the segment: an IJP followed by a prolonged phase of hyperpolarization that lasted for the duration of the distension (descending inhibition); a burst of depolarizing potentials (for up to 30 sec) that followed the termination of distensions up to 25 sec and was blocked by atropine (0.8 μM) (delayed cholinergic excitation), and a transient non-cholinergic response that immediately followed the termination of distension (non-cholinergic ‘off’ response). Apamin (0.5 μM) reduced the amplitude of the spontaneous IJPs and evoked IJPs. After apamin, distension evoked a small transient hyperpolarization at oral sites, which was similar to spontaneous events, and the prolonged hyperpolarization at anal sites. A second distension given within 20 sec of the first evoked an IJP of reduced amplitude at oral sites in every preparation. In contrast, the amplitudes of the oral Cholinergic excitation and descending inhibition were relatively unaffected by reducing the interval between distensions. Thus distension stimulates excitatory and inhibitory motor neurons supplying the circular muscle both oral and anal to the stimulus. The polarity of the reflex relies in part on the differences in timing and duration of responses as well as the transmission characteristics of the nervous pathways.     

Expression of tyrosine hydroxylase and neuropeptide tyrosine in mouse sympathetic airway-specific neurons under normal situation and allergic airway inflammation

BACKGROUND: The traditional neurotransmitter catecholamine and the neuropeptide tyrosine in sympathetic airway nerves have been proposed to be involved in the pathogenesis of airway diseases. OBJECTIVE: The aim of the present study was to investigate the effect of allergic airway inflammation on the expression of catecholamine enzyme tyrosine hydroxylase (TH), neuropeptide tyrosine (NPY) and tachykinins in mouse sympathetic airway ganglia. METHODS: Using neuronal tracing in combination with immunohistochemistry, the present study was designed to characterize TH, NPY and tachykinin profiles of superior cervical (SCG) and stellate ganglia after allergen challenge. RESULTS: The vast majority of fast blue-labelled SCG neurons (allergen: 97.5+/-1.22% (mean+/-SEM) vs. controls: 94.5+/-1.48%, P=0.18) and stellate neurons (allergen: 95.3+/-1.01% vs. controls: 93.6+/-1.33%, P=0.34) were immunoreactive for TH. Of the TH immunoreactive and fast blue-labelled SCG neurons, 52.0+/-1.01% allergen vs. 51.2+/-3.58% controls (P=0.83) and stellate neurons, 57.3%+/-0.97 allergen vs. 56.4+/-1.65% controls (P=0.64) were positive for TH only but not NPY, whereas 45.3+/-1.05% allergen vs. 43.3+/-1.18% controls (P=0.47) of fast blue-labelled SCG neurons and 37.9+/-0.86% allergen vs. 37.1+/-1.24% controls (P=0.62) of fast blue-labelled stellate neurons were immunoreactive for both TH and NPY immunoreactivities. There was a trend of an increase, but not significant one, in the percentage of TH-/NPY-immunoreactive and fast blue-labelled neurons in allergen-treated animals in comparison with the controls. Tachykinins, however, were not expressed by sympathetic neurons and were also not induced in sympathetic neurons after allergen challenge. CONCLUSION: The present study indicates that allergic airway inflammation does not alter the expression of noradrenalin and NPY in sympathetic ganglia and also shows that sympathetic neurons do not respond to allergic airway inflammation with tachykinins induction. However, a participation of catecholamine and NPY in the pathogenesis of allergic airway inflammation cannot be excluded in the present study as a higher neurotransmitter output per neuron following allergen challenge could be possible.