Failure of chronic physostigmine to ameliorate working memory deficits after medial septal lesions.

To assess the potential usefulness of chronic acetylcholinesterase inhibition in the treatment of learning/memory disorders arising from central cholinergic deficient states, physostigmine was administered chronically to rats with medial septal lesions and the retention of a spatial/working memory task investigated. Three dose levels of physostigmine (0.025, 0.

Alterations in regulatory behaviors induced by medial septal lesions and superior cervical ganglionectomy.

Following medial septal (MS) lesions peripheral sympathetic fibers, originating from the superior cervical ganglia (SCG), grow into the hippocampus and habenula. To assess their effect on regulatory behaviors, body weight, and food and water consumption were studied under ad libitum and pharmacological stress conditions, after MS lesions, superior cervical ganglionectomy (Gx) or MS lesion + ganglionectomy (MSGx). Twenty-two animals completed the study: control (n = 7), MS lesion (n = 5), Gx (n = 6), MSGx (n = 4).

Perfluorochemical emulsion effect on warfarin binding by fraction V human albumin.

A previous study demonstrated that a relatively large concentration of a perfluorochemical (PFC) emulsion caused significant displacement of bound warfarin from fatty acid free human albumin. To determine whether this displacement would occur when fatty acids were associated with albumin, the effect of the emulsion on warfarin binding by fraction V human albumin was examined. Binding of 2 and 10 micrograms/ml warfarin at room temperature by 4 per cent albumin solutions diluted with the emulsion was determined by centrifugation followed by supernatant ultrafiltration.

Effects of olsalazine in the jejunum of the rat.

Olsalazine (ADS) is the azo-linked dimer of 5-aminosalicylic acid (5-ASA). It is of value for the management of patients with ulcerative colitis but may be associated with increasing diarrhoea in a few. This study examines the effect of 5-ASA and ADS on small intestinal transport systems of the rat.

Detection and characterization of circulating rat mammary tumor cells in buffy coat and correlation with metastasis.

A new method for detecting bloodborne TMT-081 rat mammary tumor cells in buffy coat has revealed dose-dependent variations in the latency period after inoculation of tumor cells, the concentration of circulating tumor cells, and the incidence of metastases. Cells isolated from buffy coat of right ventricular blood were more tumorigenic than tryptically dispersed cells from solid tumors. With the new method circulating tumor cells can be detected at concentrations as low as 3 cells/microliter of buffy coat, or approximately 60 cells/ml of whole blood.

Loss of propranolol during ultrafiltration in plasma protein binding studies.

A commercial ultrafiltration device was examined for propranolol plasma protein binding studies. A nonspecific loss of free drug resulted in a low recovery in the ultrafiltrate. Use of a rinse filtrate did not completely compensate for this loss.

Spontaneous and elicited bag cell discharges in gonadectomized Aplysia.

The neuroendocrine bag cells of the hermaphroditic marine gastropod, Aplysia, secrete peptide hormones that induce release of ripe eggs from the ovotestis. The egg string is subsequently deposited on the substrate by means of a complex sequence of rhythmic head and neck movements. Gonadectomy (removal of the ovotestis) was performed in two closely related species of Aplysia to prevent completely the synthesis, build-up and release of eggs.

Patterns of blood-vessel invasion by mammary tumor cells.

Rat mammary tumor TMT-081 was employed as a model for blood vessel invasion because its mode of metastasis resembles that of human tumors. The invasive mechanism was studied with two methods of serial transplantation: transfer of enzymatically dispersed solid tumors, and transfer of buffy coat containing circulating tumor cells. The latter method produced greater invasion of blood vessels, including larger veins and occasionally arteries, perhaps by obviating damage to tumor cells during enzyme treatment.

The usefulness of the high voltage electron microscope in biomedical ultrastructure analysis.

We now have the tools to quantitate and correctly interpret the size, shape, and distribution of organelles in cells. It appears likely that the results will require some changes in some basic assumptions of ultrastructural cytology. This should also result in some new biochemical hypotheses about control of cell metabolism.

Buccal nitroglycerin in congestive cardiac failure: a multicentre study.

One-hundred-and-ninety-two elderly patients with symptoms of congestive cardiac failure, despite therapy with diuretics and inotropic agents, received buccal nitroglycerin as additional medication. They were assessed for up to 6 months. Improvements in symptoms and functional classification were apparent within 14 days, and were maintained for the duration of the study.

Immediate ascites conversion of mammary tumors induced in NYLR/Nya mice by 7,12-dimethylbenz-[a] anthracene and urethane feeding and by forced breeding.

Intragastric feeding of dimethylbenz-[a]anthracene in corn oil together with urethane in the drinking water and forced breeding were successful in rapidly inducing (2-4 months) mammary tumors (adenoacanthomas) in inbred NYLR/Nya mice, which have a low incidence of spontaneous breast tumors and of other tumors. The tumors could be quickly and permanently transformed to an ascites form by intraperitoneal inoculation of enzyme-dissociated cells and subsequent serial passage of free cells. Only 10 (3 in some cases) serial passages were required, thus conveniently providing multiple isogeneic carcinoma cell lines in this strain of mice.

Alterations of ultrastructure and elemental composition in cultured neonatal rat cardiac myocytes after metabolic inhibition with iodoacetic acid.

The purpose of this study was to document changes in cellular fine structure and elemental composition, and their relationship to progression of cell injury, in cultured neonatal rat cardiac myocytes in which impaired energy metabolism was produced by the metabolic inhibitor, iodoacetic acid (IAA). In order to quantitate changes in the concentrations of elements and their subcellular distribution in individual myocytes, electron probe x-ray microanalysis was performed on freeze-dried cryosections of rapidly frozen cells. After 1 hour of exposure to IAA, ATP level was not significantly reduced.

Binding of warfarin by human albumin in the presence of a perfluorochemical blood substitute.

The effect of a perfluorochemical blood substitute on ligand binding by human albumin was examined using warfarin as a model drug. Binding of warfarin by four per cent human albumin solutions diluted with either buffer or blood substitute, and by blood substitute diluted with buffer was examined. Solutions containing 2 or 10 micrograms/ml warfarin were quantitated by liquid scintillation counting using 14C-warfarin.

Dynamic exercise training in foxhounds. II. Analysis of skeletal muscle.

The purpose of this study was to determine whether 8-12 wk of endurance training produces biochemical and histochemical adaptations in skeletal muscle in foxhounds. Analyses were performed on samples removed from gastrocnemius, triceps, and semitendinosus muscles of foxhounds before and after a treadmill running program. Biochemical analysis showed that training did not alter the activities of phosphofructokinase, beta-hydroxyacyl-CoA dehydrogenase, succinate dehydrogenase, or total phosphorylase.

Electromechanical changes during electrically induced and maximal voluntary contractions: surface and intramuscular EMG responses during sustained maximal voluntary contraction.

Changes in the electrical activity of the human gastrocnemius and soleus muscles during fatiguing maximal plantar flexions were studied with computer-aided EMG frequency power spectral analysis and intramuscular spike amplitude-frequency histogram analysis. In some experiments, brief supramaximal nerve stimulations of 80 Hz were given at 15-s intervals during sustained maximal voluntary contractions (MVCs). Multiple muscle biopsy samples were also obtained from the gastrocnemius muscle for fiber type determination.

Flight-initiating interneurons in the locust.

We have used intracellular recording and staining techniques to investigate the cellular mechanisms for the initiation and maintenance of flight in the locust, Locusta migratoria. In particular, we examined the properties of a small group of interneurons in the mesothoracic ganglion. We refer to these interneurons as 404 neurons.

Spina bifida occulta: lesion or anomaly?

Failure of fusion of the posterior arches of the lumbosacral spine above S3 was sought on frontal radiographs of 653 patients attending an accident and emergency (A & E) department. The patients were aged from 2 months to 98 years and represent all those with relevant information discharged as A & E outpatients over a 2-year period. Presenting complaints of backache or enuresis and inadequate radiographs were excluded.

In vitro modulation of differentiation by calcium in organ cultures of human and murine epithelial tissue.

The differentiation of epithelial tissue in organ cultures of murine buccal mucosa, various human oral mucosa, and human newborn foreskin was found to be dependent on the calcium concentration of the culture media. In low calcium medium (less than or equal to 0.07 mM) epithelial differentiation was inhibited.

Shape changes and polarization of cells migrating through tissue. A high-voltage electron microscope and computer graphics study of serial thick sections.

Structural changes of carcinoma cells and fibroblasts migrating through small spaces in the elastic-collagen reticulum of mouse peritoneum have been studied by high-voltage electron microscopy of serial thick sections and by computer graphics reconstruction of cell profiles. The change of shape profile of an individual cell, between serial sections is large and the distribution of organelles is very non-uniform and changes markedly between sections. Conclusions about adhesion, intercell contact, cell shape and polarization of cytoplasmic organelles could only be reached by assessing a complete set of serial sections.