Showing papers by "Saint Louis University published in 1983"

Differential effects of classical and atypical antipsychotic drugs on A9 and A10 dopamine neurons

Abstract: Prolonged treatment with classical antipsychotic drugs decreased the number of spontaneously active dopamine neurons in both the substantia nigra (A9) and the ventral tegmental area (A10) of the rat brain. In contrast, treatment with atypical antipsychotic drugs selectively decreased the number of A10 dopamine neurons. Related drugs lacking antipsychotic efficacy failed to decrease dopamine activity. These findings suggest that the inability of atypical antipsychotic drugs to decrease A9 dopamine neuronal activity may be related to their lower potential for causing tardive dyskinesia and that the inactivation of A10 neurons may be involved in the delayed onset of therapeutic effects during treatment.

Rapid development of tolerance to the behavioural actions of cholecystokinin

Abstract: Cholecystokinin (CCK) acts acutely to inhibit food consumption in fasted rats, mice, sheep, pigs, monkeys and humans. CCK has been proposed as a satiety signal, inducing the behavioural sequence of satiety, or as an aversive internal stimulus, which inhibits food intake by inducing malaise. Reductions in food intake and related exploratory behaviours are initiated by CCK at its peripheral receptor in the gut, which appears to transmit sensory feedback via the vagus nerve to brain regions mediating appetitive behaviours. The therapeutic potential of CCK as an appetite suppressant in obesity syndromes rests on the demonstration of significant, long-lasting body weight reduction. Chronic CCK administration by repeated injections is problematic, since this peptide is rapidly degraded in vivo. We chose the Alzet constant infusion osmotic minipump to investigate possible alterations in body weight and food intake during continuous infusion of CCK. We now report that no change was detected in either body weight or total daily food consumption at any time point during 2 weeks of intraperitoneally (i.p.) infused CCK. The mechanism underlying the lack of chronic CCK effects appears to be a rapid development of behavioural tolerance. Acute challenge doses of CCK which induced satiety-related behaviours in saline-infused rats were ineffective in CCK-infused rats. The behavioural tolerance was apparent within a few hours of minipump implantation. These results provide the first evidence that rapid and reversible tolerance develops to the actions of a gut peptide.

Modeling some empirical vertical component Lg relations

Abstract: Higher mode surface wave theory is used to model the vertical component Lg wave observed in eastern North America at regional distances. Tests of the model are made to determine whether it is capable of describing empirical spectral scaling laws, spatial attenuation, and peak time domain Lg amplitudes. It is found that a simple crustal model and a rough estimate of crustal QB are all that are required to accomplish this. Good results are obtained if the average crustal Qp is equated to the coda Q of the same frequency. INTRODUCTION The Lg wave is a wave observed on short-period seismograms of local and regional seismic events which travels with a group velocity of approximately 3.5 km/sec in the Central United States. It is usually the largest arrival on the seismogram, which makes it suitable for defining a magnitude scale (Nuttli, 1973; Herrmann and Nuttli, 1982). As part of developing the magnitude scale, there have been many studies on the spatial attenuation of the Lg wave (Nuttli, 1973; Street, 1976; Bollinger, 1979; Singh and Herrmann, 1982). The Lg wave is usually thought of as a superposition of higher mode surface waves propagating within the crustal wave guide. Herrmann and Nuttli (1975a, b) attempted to deterministically model observed Lg amplitudes in terms of focal mechanism, focal depth, and seismic moment using surface wave techniques. They were limited by their inability to compute surface wave eigenfunctions at frequencies greater than 0.5 Hz. However, their results were encouraging. Harkrider (1979), drawing upon the work of Apsel (1979), discovered a way to compute surface wave energy integrals of the higher modes very precisely. Bache

The Eye in Bone Marrow Transplantation: I. Clinical Study

Abstract: • A prospective study of 45 patients undergoing bone marrow transplantation included full ocular examination and pretransplant and posttransplant conjunctival biopsies. The major finding was the development of a severe keratoconjunctivitis sicca syndrome that developed in 20 of the 45 patients and closely correlated with the occurrence of acute graft-v-host disease (GVHD). An acute pseudomembranous conjunctivitis in the fulminant stage of acute GVHD developed in six patients. A further ten patients made up a retrospective assessment of bone marrow transplantation and confirmed these clinical findings.

Release of dopamine and 5-hydroxytryptamine from rat striatal slices following activation of nicotinic cholinergic receptors.

Abstract: 1. 1. The administration of the nicotinic cholinergic agonists dimethylphenylpiperazinium iodide (DMPP) or nicotine caused a concentration dependent release of [3H]dopamine, [3H]5-hydroxytryptamine as well as endogenous dopamine and 5-hydroxytryptamine from superfused slices of rat striatum. 2. 2. Release of both labelled and non-labelled transmitter was antagonized by the nicotinic antagonist, hexamethonium but not the muscarinic antagonist, atropine. 3. 3. The present study provides additional evidence that nicotinic-cholinergic receptors are present in the mammalian central nervous system. 4. 4. Activation of these nicotinic-cholinergic receptors in the striatum results in the release of both dopamine and 5-hydroxytryptamine.

Primary anaplastic small cell (oat cell) carcinoma of the larynx: Review of the literature and report of 18 cases

Abstract: Anaplastic small cell (oat cell) carcinoma is a neoplasm commonly arising in the lungs. However, it may also occur, though rarely, in the larynx. A series of 43 cases is presented (ten cases from the Armed Forces Institute of Pathology, eight from the Department of Otolaryngology of the Padua University, and 25 from the literature). The tumor often presents in the sixth and seventh decades of life and appears to be highly aggressive, and metastases develop early. The most common presenting symptom is hoarseness. As in pulmonary small cell carcinoma, prognosis is poor and does not seem to depend upon therapeutic modalities, tumor location or the extent of initial local disease. The tumor seems to derive from the Kulchitsky cell present not only in the bronchial mucosa but also in the laryngeal lining. Like pulmonary anaplastic small cell carcinoma, small cell carcinoma of the larynx should be treated with systemic chemotherapy and radiotherapy. The association of small cell carcinoma with squamous carcinoma of the larynx is also reported and problems connected with the histogenesis of this mixed tumor are discussed.

Construction of a shuttle vector for the filamentous fungus Neurospora crassa

Abstract: We have constructed a recombinant plasmid, pALS-1, that replicates autonomously in both Neurospora and Escherichia coli. pALS-1 consists of the mitochondrial plasmid from Neurospora strain P405-Labelle, the Neurospora qa-2+ gene, and E. coli plasmid pBR325. pALS-1 transforms the Neurospora qa-2+ gene at frequencies 5- to 10-fold higher than those for plasmids that transform mainly by integration. When E. coli was transformed with DNA from Neurospora transformants, we recovered not only pALS-1 but also a smaller plasmid, pALS-2, which had undergone deletion of most and possibly all Labelle sequences, and the immediately flanking sequences in pBR325. pALS-2 also appears to replicate autonomously in Neurospora, but less efficiently than does pALS-1. Southern blots show that free pALS-1 and pALS-2 are present in nuclear and cytosolic (supernatant from high-speed centrifugation) fractions of Neurospora transformants and that small, variable proportions of the plasmids also can be detected in mitochondria. pALS-1 and pALS-2 constitute putative shuttle vectors for Neurospora.

Filamentous fungi functional replicating extrachromosomal element

Abstract: A functional extrachromosomal element capable of replication in filamentous fungi is provided. The extrachromosomal element employs (1) a mitochondrial replicating element or (2) a lower organism replication sequence recognized by the fungus, in combination with foreign DNA to provide replication, transcription, and translation of foreign regulatory elements and genes. The extrachromosomal element is exemplified by a mitochondrial replicating system from Neurospora. The cell strain E. coli HB101 containing the plasmid pALS-1-1 has been deposited at the A.T.C.C. on July 13, 1982, for patent purposes and given the designation ATCC 39157. The cell strain E. coli HB101 containing the plasmid pALS-2 has been deposited at the A.T.C.C. on July 13, 1982, for patent purposes and given the designation ATCC 39158.

Fine structure of nigral and pallidal afferents in the thalamus: an EM autoradiography study in the cat.

Abstract: Ultrastructural characteristics and distribution of nigral and pallidal axon terminals on thalamic neurons were studied after injections of tritiated leucine into substantia nigra and entopeduncular nucleus respectively. Adult cats received 0.1–0.2-μl injections of 2, 3, 4, 5, 3H-leucine in a concentration 60 μCi/μl and were allowed to survive for 4–5 days. The brain tissue was processed for electron (EM) and light microscopic (LM) autoradiography. EM samples were obtained from the ventral medial and ventral anterior thalamic nuclei. Ultrastructural features of labelled nigral and pallidal boutons were analyzed both qualitatively and quantitatively. Ultrastructural characteristics of nigral and pallidal boutons appeared similar. Their length along postsynaptic membrane ranged from 0.8 to 10 μm, with average length of apposition around 2 μm. Both types of bouton contained small clear vesicles of extremely variable shape and formed symmetrical type contacts. Mean diameter of synaptic vesicles profiles (n = 500) was 32.5 nm and 33.3 nm in nigral and pallidal terminal respectively, and mean vesicle profile areas were 846 nm2 in nigral terminals and 878m2 in pallidal. Both parameters showed normal distribution in percentage distribution histograms. The mean ratios of longest and shortest diameters was 1.6 for synaptic vesicles in both types of boutons. Thus, no significant differences in morphological parameters of nigral and pallidal axon terminals were discovered except that pallidal afferents often formed “en passant”-type synapses while nigral did not. However, this feature alone is not sufficient for distinction between the two types of termi-nals in unlabelled tissue. Analysis of distribution of synaptic sites showed that only pallidal bou-tons formed axosomatic synapses on thalamocortical projection neurons (TCPN), which comprised 21% of total number of pallidal terminals studied. On primary dendritic trunks of TCPN the proportion of nigral boutons was larger (28.8%) as compared to pallidal (19%). The percentage of both types of bouton contacting secondary TCPN dendrites was similar (36% pallidal, 30.6% nigral), while the proportion of nigral terminals on tertiary TCPN den-drites was larger (23.6% versus 13%). Both afferents revealed a tendency to synapse preferentially at the branching points of TCPN dendrites with sev-eral boutons often found along the perimeter of the branching site. Small but equal proportions (8%) of both types of axon terminal were found to synapse on vesicle-containing dendrites of local circuit neurons. Nigral boutons were also found in complex synaptic arrangements in glomeruli. It is concluded that the organizations of pallidal and nigral afferent in-puts in the thalamus are rather similar. Both occupy strategic positions which would allow them to exert strong influence on the firing pattern of TCPN.

Cytodifferentiation and alkaloid accumulation in cultured cells of Papaver bracteatum

Abstract: Cultured Papaver bracteatum cells accumulate large amounts of dopamine (01–4 mg/g fresh wt) and much lower levels of the alkaloids, thebaine (0–6 μg/g fresh wt) and sanguinarine (10–500 μg/g fresh wt) Upon removal of hormone from their culture media, organogenesis and an elevation in morphinan alkaloid concentration were observed Light and electron microscopic studies reveal that a correlation exists between the appearance of laticifer-like cells and thebaine in these cells

Periodic, multimodal distribution of granule volumes in mast cells.

Abstract: The areas of 2327 mast cell granules in transmission electron micrographs of sections of peritoneal mast cells from adult rats were measured by digitized planimetry. A histogram constructed using equivalent volumes calculated from the measured areas assuming approximation of the granules to spheres showed a periodic multimodal distribution in which the modes fell at volumes that were successively larger integral multiples of the volume at the first mode. Application of a moving-bin technique to the data confirmed the presence of the modes. We propose a mechanism of fusion of unit sized granules to account for the multimodal distribution. The presence of pear- and dumbbell-shaped granules in mast cells is consistent with this mechanism.

Cardiovascular Adjustments to Isometric Contractions: Static Effort

Abstract: The sections in this article are: 1 General Description of Cardiovascular Responses 1.1 Local Circulation 1.2 Cardiac and Systemic Vascular Responses 1.3 Baroreceptor Influence 2 Mechanisms of Control of Systemic Cardiovascular Responses 2.1 Efferent Pathway 2.2 Afferent Pathway 3 Summary: Central Command or Reflex?

Transient cerebrocerebellar projections in kittens: postnatal development and topography.

Abstract: Orthograde and retrograde labeling techniques were used to study the ontogenesis of transient cerebrocerebellar projections in kittens. Tritiated amino-acid or horseradish peroxidase injections were made into the coronal gyrus of the primary somatosensory cortex of kittens 1-70 postnatal days old. Orthogradely labeled axons were observed bilaterally in the superior and inferior cerebellar peduncles in kittens between 6 and 49 postnatal days of age. Most cerebrocerebellar axons labeled on the ipsilateral side arise from the pyramidal tract as it courses through the pontine nuclei. These axons descend through the pontine tegmentum as a diffusely organized corticotegmental tract and enter the ipsilateral superior cerebellar peduncle. Fewer cerebrocerebellar axons leave the pyramidal tract caudal to the pontine nuclei and project into the contralateral superior cerebellar peduncle. Cerebrocerebellar projections through the superior cerebellar peduncles terminate primarily in the cerebellar nuclei, where they are localized in the interpositus nuclei and in immediately adjacent areas of the dentate and fastigial nuclei. More caudally, labeled axons exit from the pyramidal tract and take a superficial route around the ventrolateral brainstem into the inferior cerebellar peduncles bilaterally. These projections are more numerous contralaterally and are directed primarily to the internal granule cell layer of the posterolateral folia of the anterior lobe, the posteromedial simplex lobule, and the dorsal paramedian lobule. Horseradish peroxidase injections were made into the cerebellar posterior lobe and deep nuclei and the results from these cases showed that the cerebrocerebellar pathway originates from pyramidal neurons in layer V primarily in the coronal, the precoronal, and the anterior and posterior sigmoid gyri on both sides. In these gyri, many of the HRP-positive neurons were found in clusters of two to five neurons, aligned in anterior-posterior strips. The results from all experiments provide evidence about the ontogeny of cerebrocerebellar projections. Projections through the superior cerebellar peduncles generally develop at 6-8 postnatal days of age, whereas projections through the inferior cerebellar peduncles first are seen at 8-10 days postnatally. Cerebrocerebellar projections reach their maximum development in the second postnatal week but sharply decrease in density during the third postnatal week. No cerebrocerebellar projections were observed after the seventh postnatal week of development. Possible functional implications for this transient projection are discussed.

Short-period Lg magnitudes: Instrument, attenuation, and source effects

Abstract: The applicaton of the Nutli (1973) definition of the m bLg magnitude to instruments and wave periods other than the short-period WWSSN seismograph is examined. The basic conclusion is that the Nuttli (1973) definition is applicable to a wider range of seismic instruments if the log 10 ( A/T ) term is replaced by log 10 A . For consistency and precision, the notation m bLg should be applied only to magnitudes based upon 1.0 Hz observations. The m bLg magnitude definition was constrained to be consistent with teleseismic P -wave m b estimates from four Central United States earthquakes. In general, for measurements made at a frequency f , the notation m Lg ( f ) should be used, where m L g ( f ) = 2.94 + 0.833 log ⁡ 10 ( r / 10 ) + 0.4342 γ r + log ⁡ 10 A , and r is the epicentral distance in kilometers, γ is the coefficient of anelastic attenuation, and A is the reduced ground amplitude in microns. Given its stability when estimated from different instruments, the m Lg ( f ) magnitude is an optimum choice for an easily applied, standard magnitude scale for use in regional seismic studies.

The Role of Mast Cells in Asthma

Abstract: Mast cells store or generate a number of substances, such as histamine, leukotrienes, specific chemotactic factors, and proteases, which have potent inflammatory effects. Mast cells are present in mammalian lung in the bronchial wall, in the epithelium itself, and in airway lumens. Evidence implicating mast cells in the induction of airway muscle constriction and mucosal inflammation includes direct studies of mast cell secretion, measurement of histamine release, and inhibition of asthmatic reactions with antihistamines and with the inhibitor of mast cell degranulation, sodium cromoglycate. Definitive evaluation of the role of the mast cell in asthma remains elusive, in part because of the general hyperactivity of airway smooth muscle in asthmatics.