Reduction of extracellular Na+ causes a release of Ca2+ from internal stores in airway epithelial cells.

Exchange of physiological salt solution with Na(+)-free solution caused an increase in intracellular Ca2+ concentration ([Ca2+]i) in 86.3% of cultured airway epithelial cells within 75 s. [Ca2+]i returned to near baseline levels within 45 s and frequently showed oscillatory increases thereafter.

A mechanism for entrapment of the tibialis posterior tendon in lateral subtalar dislocation.

The entrapment of the tibialis posterior tendon causing a block to reduction of lateral subtalar dislocation is recognized. The mechanism which allows tendon excursion is less clearly understood. We present a case in which extensive tearing of the musculotendinous junction of the tibialis posterior muscle occurred during tendon displacement and entrapment in lateral subtalar dislocation.

Stretch increases inositol 1,4,5-trisphosphate concentration in airway epithelial cells.

Mechanical stimulation of airway epithelial cells with a microprobe leads to an increase in cytoplasmic [Ca2+] that appears to be due, in part, to release of Ca2+ from inositol 1,4,5-trisphosphate (IP3)-sensitive stores (Boitano et al., Science 258:292[1992]). To investigate whether intracellular IP3 concentration ([IP3]i) increases in response to mechanical stimulation, we grew confluent monolayers from rabbit tracheal mucosal explants on flexible substrates and measured [IP3]i after stretching the substrate.

Evidence for voltage-sensitive, calcium-conducting channels in airway epithelial cells.

In airways epithelial cultures, mechanical stimulation induces intracellular Ca2+ concentration ([Ca2+]i) changes by causing Ca2+ entry and intracellular Ca2+ release. Mechanically induced Ca2+ fluxes across the plasma membrane are blocked by Ni2+ (Boitano, S., M.

Tuning the properties of poly(p-phenylenevinylene) for use in all-optical switching.

We show that, as the conjugation length of poly(p-phenylenevinylene) increases, the ratio of its two-photon absorption coeff icient to third-order nonlinearity at 800 nm decreases, rendering the material suitable for alloptical switching.

Fetal Ammon's horn transplants improve acquisition of a radial arm maze and a low-rate operant schedule in trimethyltin-treated rats.

The results of previous studies indicated that block grafts of fetal hippocampal tissue made into cavities produced by aspiration lesions of the hippocampus in rats given the neurotoxin trimethyltin (TMT) significantly worsened the TMT-induced deficit in water maze acquisition. The purpose of the present study was to test the hypothesis that a procedure for transplantation that produced less destruction to the host brain and resulted in transplants with less mass might produce recovery in a spatial learning task in TMT-exposed rats. Acquisition of an externally cued (spatial) version of the radial arm maze (RAM), an internally cued version of the RAM, and of a differential reinforcement of low rate (DRL) operant schedule was assessed in normal rats, rats given TMT, and rats given TMT and stereotaxic implants of either fetal Ammon's horn or entorhinal cortex.

The effect of time following exposure to trimethyltin (TMT) on cholinergic muscarinic receptor binding in rat hippocampus.

Adult male Long-Evans rats were given 6 mg/kg trimethyltin (TMT). Rats were killed 1, 3, 7, 14, 21, 35, or 60 d later. An untreated control group was included.

Effects of trimethyltin (TMT) on choline acetyltransferase activity in the rat hippocampus. Influence of dose and time following exposure.

Trimethyltin (TMT) destroys specific subfields of the hippocampus in the rat. TMT also increases choline acetyltransferase (ChAT) activity in CA1 of Ammon's horn and the outer molecular layer of the dentate gyrus. This observation suggests that axonal sprouting occurs in the cholinergic septohippocampal system in response to TMT.

Effects of trimethyltin on acquisition and reversal of a light-dark discrimination by rats.

The behavioral deficits produced by trimethyltin (TMT) are usually attributed to the hippocampal damage caused by this toxicant. The purpose of this experiment was to determine the effects of TMT administration on acquisition and reversal of a discrete trial light-dark discrimination. Acquisition of this task is impaired by hippocampal lesions but the effects of TMT on it are not known.

Fate of Salmonella spp., Listeria monocytogenes ,and Indigenous Spoilage Microorganisms in Home-style Salads Prepared with Commercial Real Mayonnaise or Reduced Calorie Mayonnaise Dressings.

Two home-style salads, chicken and macaroni, were prepared with three different commercial mayonnaise products: (i) real mayonnaise, (ii) reduced calorie mayonnaise dressing, and (iii) reduced calorie/reduced fat mayonnaise dressing. The salads were inoculated with 10/ml levels of Salmonella spp. or Listeria monocytogenes and held at 4°C (refrigeration) and 12.

Transplant-induced working memory deficits in hippocampectomized rats.

This experiment determined the effects of transplantation of fetal hippocampus on the ability of male rats with hippocampal lesions to acquire versions of a radial arm maze that depended on either extramaze cues or intramaze cues for solution. Rats receiving transplants took significantly more trials than control rats to emit three consecutive errorless trials in the extramaze cue (spatial) variation of the maze. Rats with just hippocampal lesions never differed from any other group.

Angiotensin II binding sites in the hamster brain: localization and subtype distribution.

This study was designed to characterize the distribution of angiotensin II (AII) binding sites in the hamster brain. Brain sections were incubated with [125I][sar1,ile8]-angiotensin II in the absence and presence of angiotensin II receptor subtype selective compounds, losartan (AT1 subtype) and PD123177 (AT2 subtype). Binding was quantified by densitometric analysis of autoradiograms and localized by comparison with adjacent thionein stained sections.

Surface morphology of fetal neural transplants into the lateral ventricles after hippocampal lesions.

The surface morphology of transplants of rat fetal hippocampal tissue, and of cavities formed by aspiration lesion of the adult rat hippocampus and overlying neocortex into which the transplants were placed, was studied by scanning electron microscopy. The surface of lesion cavities was covered by a scar upon which occasional cellular profiles were found. The surface cells resembled supraependymal macrophages.

Effects of transplantation of fetal hippocampal or hindbrain tissue into the brains of adult rats with hippocampal lesions on water maze acquisition.

Rats were given bilateral aspiration lesions of the hippocampus. Some of these rats then received bilateral transplants of fetal hippocampal or dorsal ventricular ridge tissue that was dissected from embryonic rat brains at 16 or 17 days of gestation. The remaining rats with hippocampal lesions did not receive fetal brain transplants.

Helix aspersa neurons maintain vigorous electrical activity when co-cultured with intact H. aspersa ganglia.

1. Identified neurons from the right parietal lobe of the circumoesophageal ganglion of adult land snails, Helix aspersa, were isolated and placed in primary cell culture. 2.

Modified gas chromatographic/mass spectrometric method for determination of daminozide in high protein food products.

A modified version of the Conditt and Baumgardner gas chromatographic/mass spectroscopic (GC/MS) method for determination of daminozide in peanut butter and raw peanuts is described. Daminozide in the food product is hydrolyzed to unsymmetrical dimethylhydrazine (UDMH) by sodium hydroxide digestion. The generated UDMH is distilled from the food matrix and captured by reaction with salicylaldehyde in a condensation trap.

A randomized trial evaluating leuprolide acetate before hysterectomy as treatment for leiomyomas.

Fifty premenopausal patients requiring hysterectomy as treatment for symptomatic uterine leiomyomas, which were the size of 14 to 18 weeks' gestation, were randomized into two groups to determine whether preoperative gonadotropin-releasing hormone agonist would increase the feasibility of vaginal rather than abdominal hysterectomy. The control group (group A; n = 25) did not receive preoperative gonadotropin-releasing hormone agonist, but patients in Group B (n = 25) received 2 months of gonadotropin-releasing hormone agonist before undergoing hysterectomy. Patients in the two groups were similar with respect to age, gravidity, parity, pretreatment uterine size, and hemoglobin and hematocrit levels.

Cobalt-dependent potentiation of net inward current density in Helix aspersa neurons.

A low concentration of transition metal ions Co2+ and Ni2+ increases the inward current density in neurons from the land snail Helix aspersa. The currents were measured using a single electrode voltage-clamp/internal perfusion method under conditions in which the external Na+ was replaced by Tris+, the predominant external current carrying cation was Ca2+, and the internal perfusate contained 120 mM Cs+/0 K+; 30 mM tetraethylammonium (TEA) was added externally to block K+ current. In the presence of Co2+ (3 mM) or Ni2+ (0.

Trimethyltin increases choline acetyltransferase in rat hippocampus.

The environmental neurotoxin trimethyltin (TMT) destroys parts of the hippocampal formation as well as the entorhinal cortex but leaves the septal cholinergic projection to the hippocampus and dentate gyrus intact. In this study we measured choline acetyltransferase (ChAT) activity in micropunch samples of the dentate gyrus, the CA1 region of Ammon's horn, and the caudate-putamen as a measure of density of cholinergic innervation in control rats and rats exposed to 7 mg/kg TMT by means of gastric intubation. Three months after the rats were exposed to a single dose of TMT both the dentate gyrus and CA1 demonstrated significantly higher ChAT activity in TMT-exposed rats than in control rats.

Anatomical and behavioral sequelae of fetal brain transplants in rats with trimethyltin-induced neurodegeneration.

The effect of transplants of either fetal hippocampal or dorsal ventricular ridge (DVR) tissue into the brains of adult male rats exposed to TMT was determined for two behavioral tasks. Administration of TMT produced deficits in acquisition and performance of an operant differential reinforcement of low response rates (DRL) schedule and learning in the Morris water maze. The fetal transplants developed well within the TMT-damaged brains of the adult rats and numerous axons could be shown to cross the host-transplant interface.

Neurochemical anatomy of fetal hippocampus transplanted into large lesion cavities made in the adult rat brain.

The purpose of the present study was to determine whether neurochemicals normally found within neuron somata, fibers, and terminals of the hippocampal formation would also be present in transplanted hippocampal tissue that had developed in lesion cavities made in adult rat brains by aspiration of the hippocampus and overlying dorsolateral neocortex. Embryonic Day 15 or 16 rat brian tissue containing hippocampus with some medial pallial anlage was transplanted into the site of hippocampal aspiration lesions in adult male rats. One hundred ten to one hundred thirty-five days later the brains of these rats were sectioned and processed using the avidin-biotin-horseradish peroxidase immunocytochemical procedure to visualize choline acetyltransferase, met-enkephalin (MENK), neurotensin (NT), somatostatin, substance P, tyrosine hydroxylase (TH), or vasoactive intestinal polypeptide.

The effects of stimulation of the A5 region on blood pressure and heart rate in rabbits.

The effects of stimulation of the A5 cell group of the caudal ventrolateral pons electrically or with L-glutamate on heart rate and blood pressure were determined in rabbits. Electrical stimulation caused blood pressure increases and reflex bradycardia. L-glutamate caused decreases in blood pressure and heart rate which were blocked by the L-glutamate antagonist aminophosphoheptanoic acid.

Exposure to trimethyltin significantly enhances acetylcholinesterase staining in the rat dentate gyrus.

Trimethyltin (TMT) is known to produce substantial damage to the hippocampal formation. It also destroys neurons within the entorhinal cortex, thereby causing degeneration of perforant path afferents that terminate in the outer molecular layer (OML) of the dentate gyrus. Surgical destruction of the entorhinal cortex also causes the perforant path to degenerate.