Room temperature culture extends the useful life of adult neurons for voltage-clamp experiments.

Isolated superior cervical ganglion (SCG) neurons were maintained in vitro at 22 degrees C (22 degrees C neurons) for up to 4 days in an effort to inhibit process outgrowth and thus extend the useful life of SCG neurons for voltage-clamp experiments. The neurons were viable after 4 days in vitro and remained roughly spherical whereas neurons maintained in vitro at 37 degrees C (37 degrees C neurons) developed extensive neurite processes after 2 days. The resting potential of 22 degrees C neurons was more hyperpolarized and the action potential duration was reduced compared to acutely isolated neurons (acute neurons) or 37 degrees C neurons.

A retrospective study of marital discord in pilots: the USAFSAM experience.

This exploratory retrospective multi-case study investigates marital discord in USAF pilots as part of an overall concern with mission safety. Seventeen USAF School of Aerospace Medicine (USAFSAM) cases involving marital distress were reviewed, using a standardized format. Duration of martial discord ranged from 1-10 years with an average of 2.

AIDS education in rural Uganda--a way forward.

A survey of acquired immunodeficiency syndrome (AIDS)-related knowledge and attitudes was conducted during July and August 1988 in rural SW Uganda. The aim was to assess the impact of Uganda's AIDS education programme and to consider how future programmes could be more effectively implemented. Four hundred and seventy-six individuals aged 12-45 years were selected by a quota method, to form a sample stratified by age and sex.

Norepinephrine blocks a calcium current of adult rat sympathetic neurons via an alpha 2-adrenoceptor.

The effects of alpha-adrenoceptor agonist and antagonist drugs on the Ca2+ current of acutely isolated adult rat superior cervical ganglion (SCG) neurons were investigated to characterize the adrenoceptor which mediates a catecholamine-induced decrease of the Ca2+ current. Ca2+ currents were recorded using the whole-cell variant of the patch-clamp technique from neurons isolated enzymatically from adult rat SCG. Norepinephrine (1 microM) produced a rapid, reversible, and concentration-dependent decrease in Ca2+ current amplitude and slowed the rising phase of the Ca2+ current.

Potassium currents of acutely isolated adult rat superior cervical ganglion neurons.

K+ currents of adult rat superior cervical ganglion neurons were studied using the voltage-clamp technique. Neuronal somata were dissociated from the ganglion using an enzymatic dispersion technique and voltage-clamped using the whole-cell patch-clamp technique. In solutions designed to isolate K+ currents, depolarization from a prepulse potential of -100 mV induced both transient and sustained outward current components.

Somatostatin blocks a calcium current in rat sympathetic ganglion neurones.

1. The effects of somatostatin and somatostatin analogues on a Ca2+ current from acutely isolated and short-term (24-48 h) cultured adult rat superior cervical ganglion (SCG) neurones were studied using the whole-cell variant of the patch-clamp technique. 2.

Somatostatin cyclic octapeptide analogs which preferentially bind to SOMa receptors block a calcium current in rat superior cervical ganglion neurons.

To characterize further the somastatin (SOM) receptor mediating Ca2+ current reduction in rat superior cervical ganglion (SCG) neurons, the effects of three synthetic SOM octapeptide analogs, D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (IM-4-82), D-Nal-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (DC 13-116), and D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-OL (SMS 201-995), which bind preferentially to pituitary SOM receptors (SOMa) were investigated. Ca2+ currents were recorded using the whole-cell variant of the patch-clamp technique from neurons isolated enzymatically from adult rat SCG. Application of the SOM analogs (0.

Neuropeptide Y blocks a calcium current in C cells of bullfrog sympathetic ganglia.

The effects of neuropeptide Y (NPY) on the Ca2+ current of enzymatically dispersed neuronal somata from bullfrog paravertebral sympathetic ganglia were investigated using the patch-clamp technique. In C neurons, NPY induced a concentration-dependent decrease in the amplitude of the Ca2+ current and induced a slow biphasic current rising phase. Upon removal of NPY these parameters returned to near control values.

Sodium and calcium currents of acutely isolated adult rat superior cervical ganglion neurons.

Neurons enzymatically isolated from the adult rat superior cervical ganglion (SCG) were investigated using the whole-cell variant of the patch-clamp technique. Current-clamp studies revealed the following mean passive and active membrane properties: resting membrane potential, -54.9 mV; input resistance, 349 M omega; action potential (AP) threshold, -29.

The effect of pumiliotoxin-B on the excitability of bullfrog sympathetic neurons.

The effects of the alkaloid pumiliotoxin-B were investigated on neurons from bullfrog paravertebral ganglia using current-clamp techniques. Pumiliotoxin-B (2 microM) induced repetitive action potential discharge or bursting pacemaker activity in response to a single stimulus. The toxin had no significant effect on the mean resting potential or action potential characteristics of single action potentials evoked prior to the action potential discharge onset.

Voltage-clamp models for the study of acute and chronic effects of ethanol on ionic currents in adult mammalian neurons.

The aim of this study was to develop and characterize a model system in which the effects of ethanol on voltage- and agonist-gated ionic currents in adult mammalian neurons could be studied using voltage-clamp techniques. We have found that neurons enzymatically isolated from the peripheral (nodose and superior cervical ganglia) and central nervous system (pyramidal layer of the hippocampus) of the adult rat and guinea pig provide several advantages over conventional neuronal preparations (e.g.

Somatostatin blocks a calcium current in acutely isolated adult rat superior cervical ganglion neurons.

Somatostatin-like immunoreactivity has been reported to occur in the postganglionic neurons of sympathetic ganglia. We therefore investigated the effect of somatostatin (SOM) on the Ca2+ current in sympathetic neurons. Voltage-clamp recordings, using the whole-cell patch-clamp technique, were made from acutely isolated adult rat superior cervical ganglion (SCG) neurons in solutions (external and internal) designed to isolate Ca2+ currents.

Tetrodotoxin-resistant sodium current of rat nodose neurones: monovalent cation selectivity and divalent cation block.

1. Monovalent cation selectivity and divalent cation sensitivity of the tetrodotoxin (TTX)-resistant Na+ current in dissociated adult rat nodose ganglion neurones were investigated using the whole-cell patch-clamp technique. 2.

Somatostatin, an inhibitor of ACTH secretion, decreases cytosolic free calcium and voltage-dependent calcium current in a pituitary cell line.

Somatostatin is a neurohormone peptide that inhibits a variety of secretory responses in different cell types. We have investigated the effects of somatostatin on calcium current and intracellular free calcium in AtT-20 cells, a pituitary tumor line in which the inhibitory actions of this peptide have been well characterized. At concentrations similar to those that inhibit adrenocorticotropic hormone (ACTH) release, somatostatin and its analogs reduced the levels of intracellular free calcium (as measured by the Quin-2 technique).

Na+ and Ca2+ currents of acutely isolated adult rat nodose ganglion cells.

The electrical properties of nodose ganglion cells acutely isolated from adult rats were studied using the whole-cell patch-clamp recording method. Current-clamp recordings revealed a mean resting membrane potential of -54.3 mV and an input resistance of 527 M omega.

The persistence of Legionella pneumophila in non-sterile, sterile and artificial hard waters and their growth pattern on tap washer fittings.

Simultaneous experiments were performed with sterilized and non-sterile water and an artificial hard water. After seeding with an environmental isolate of Legionella pneumophila numbers in the sterile and hard water decreased rapidly and colonization of various tap washer fittings failed to take place. Adhesion and growth of an environmental isolate of L.

Lipid and wall amino acid composition in the classification and identification of Arachnia propionica.

Two strains of Arachnia propionica and two Arachnia-like isolates were degraded by alkaline methanolysis and the non-hydroxylated fatty acid esters released were examined by thin-layer and gas chromatography. The fatty acid profiles obtained were both qualitatively and quantitatively similar and were comprised of iso-, anteiso- and straight chain saturated fatty acids with 13-methyltetradecanoic acid (i-15) and 12-methyltetradecanoic acid (ai-15) as major components. One of the Arachnia-like strains (HIK 288) had, in addition to i-15 and ai-15, major amounts of pentadecanoic acid (15:0).

A note on the survival of Legionella pneumophila in stagnant tap water.

Tap water, from an experimental hot water system, containing a known virulent strain of Legionella pneumophila was stored in screw-capped bottles for 14 months. Viable counts showed survival of L. pneumophila and at least three other bacterial species.

Diaphanography in the diagnosis of breast cancer.

In diaphanography, a light source is applied to the breast to visualize lesions through a television camera sensitive to infrared light. Diaphanography and mammography were performed on 1,476 patients in a screening population. Twenty-six cancers in 24 patients were confirmed by biopsy; detection rates were 96% for mammography, 58% for diaphanography, and 62% for physical examination.

Single acetylcholine channel currents in sympathetic neurons.

Single acetylcholine (ACh) channel currents were studied by the gigaohm patch-clamp technique in cultured sympathetic neurons of the bullfrog, Rana catesbeiana. Recordings were made at 22 degrees C on cell-attached and excised membrane patches. When ACh (0.

Chromosome studies in plutonium workers.

Chromosome analyses have been performed on peripheral blood lymphocytes from 54 men with estimates of plutonium body burdens in excess of 296 Bq. Both stable and unstable aberrations were scored using a banding technique and breakpoints noted. In discussing the significance of aberration frequencies the relative proportions of the different types of aberration and their distribution have been considered and account has been taken of external radiation exposure.

Colonization of components of a model hot water system by Legionella pneumophila.

A model hot water distribution network was seeded with a virulent strain of Legionella pneumophila serotype 1. Ten weeks after inoculation, components of the system, which include aluminium discs, copper, stainless steel, silicone tubing, rubber and glass beads, were examined for colonization by L. pneumophila.

Survival of Legionella pneumophila in a model hot water distribution system.

A virulent strain of Legionella pneumophila was inoculated into an enclosed system supplied with unsterilized water from a domestic hot water supply. Growth of bacteria was monitored over 10 weeks. An increase in the number of organisms other than legionellas occurred but few amoebae were observed and none could be cultured.