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Biomedical subjects

A Weindl

Publications and source records attributed to A Weindl.

At least 55 records · Page 3Linked to original sources
PubMed1984

Neurons of the A1/A2 region in the guinea pig medulla oblongata containing glucagon, glicentin, and dopamine-beta-hydroxylase immunoreactivity.

Glucagon- (GLU-IR), glicentin- (GLI-IR) and dopamine-beta-hydroxylase (DBH-IR) immunoreactive neurons were mapped in the medulla oblongata of colchicine pretreated guinea pigs. Numerous GLU-IR and GLI-IR perikarya are located in the area of the nucleus ambiguus, in the adjacent formatio reticularis, and less frequently in the nucleus reticularis lateralis, the nuclei raphe obscurus and commissuralis and the caudal part of the nucleus solitarius. In these nuclei, the coexistence of glicentin and glucagon within the same perikarya is demonstrated. DBH-IR is also found in neurons of the nuclei commissuralis, solitarius and reticularis lateralis (A1/A2 system of Dahlström and Fuxe 1964, 1965). However, a coexistence of GLU/GLI-IR and DBH-IR within the same neuron is not observed.

Animals↗
PubMed1984

Distribution of NT-IR perikarya in the brain of the guinea pig with special reference to cardiovascular centers in the medulla oblongata.

The occurrence and distribution of neurotensin-immunoreactive (NT-IR) perikarya was studied in the central nervous system of the guinea pig using a newly raised antibody (KN 1). Numerous NT-IR perikarya were found in the nuclei amygdaloidei, nuclei septi interventriculare, hypothalamus, nucleus parafascicularis thalami, substantia grisea centralis mesencephali, ventral medulla oblongata, nucleus solitarius and spinal cord. The distribution of NT-IR perikarya was similar to that previously described in the rat and monkey. In the gyrus cinguli, hippocampus and nucleus olfactorius, though, no NT-IR neurons were detected in this investigation. Additional immunoreactive perikarya, however, were observed in areas of the ventral medulla oblongata, namely in the nucleus paragigantocellularis, nucleus retrofacialis and nucleus raphe obscurus. The relevance of the NT-IR perikarya within the ventral medulla oblongata is discussed with respect to other neuropeptides, which are found in this area, and to cardiovascular regulation.

Animals↗
PubMed1984

Somatostatin in the brain of the turtle Testudo hermanni Gmelin. An immunohistochemical mapping study.

An immunohistochemical mapping study in the brain and upper spinal cord of the turtle Testudo hermanni Gmelin revealed a wide distribution of somatostatin perikarya and fibres. Within the telencephalon, somatostatin perikarya are present in the anterior olfactory nucleus, in the medial, dorsomedial and dorsal cortex, in the pallial thickening, in the piriform cortex, paleostriatum augmentatum, in the dorsoventricular ridge, core nucleus of the dorsoventricular ridge, in area c and d, and in the amygdala. In the diencephalon, the periventricular nucleus of the hypothalamus contains many somatostatin perikarya. Cerebrospinal fluid contacting somatostatin perikarya of the infundibular nucleus terminate with club-like endings in the ventricular cavity. Some somatostatin perikarya are present in the nu. reuniens of the thalamus and in the lateral habenular nucleus of the epithalamus. Within the mesencephalon somatostatin perikarya are located in the interpeduncular nucleus, area tegmentalis ventralis and in the nu. reticularis isthmi. In the rhombencephalon, somatostatin perikarya are encountered in the nu. raphe superior, nu. reticularis magnus, periventricular grey matter, bed nucleus of the fasciculus longitudinalis medialis and in the nu. solitarius-vagus complex. Somatostatin fibres form a circular band in the olfactory bulb. In the telencephalon, dense aggregations of somatostatin fibres are present in the anterior olfactory nucleus, in the pallial thickening, in the parahippocampal gyrus, cortex medialis, dorsomedialis, dorsalis and piriformis, in the dorsal ventricular ridge, paleostriatum augmentatum, area c and d, in the septum, nu. diagonalis of Broca, in the amygdala and in the anterior commissure. In the diencephalon, somatostatin fibres terminate at the vessels of the organum vasculosum of the lamina terminalis. A dense band of somatostatin fibres surrounds the rostral third ventricle. Somatostatin fibres terminate in the infundibulum at portal capillaries, and in the neural lobe. Somatostatin fibres are found in the periventricular, ventromedial and lateral nucleus of the hypothalamus. In the thalamus, the area triangularis, the dorsomedial and dorsolateral area and the nu. reuniens contain somatostatin fibres. Somatostatin fibres are very dense in the lateral habenular nucleus. At the mesencephalic level, somatostatin fibres are found in the pretectal nucleus, in the deep layers of the tectum, in the nu. tori semicircularis lateralis, in the interpeduncular nucleus, area tegmentalis ventralis, nu. ruber, substantia nigra and periventricular grey.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

Opioid peptide-like immunoreactivity localized in GABAErgic neurons of rat neostriatum and central amygdaloid nucleus.

Opioid peptide-like (OPL)-immunoreactivity and (the GABA-biosynthetic enzyme) glutamic acid decarboxylase-like (GAD)-immunoreactivity were localized in rat neostriatum and central amygdaloid nucleus (ACE) using a polyclonal sheep antiserum to rat brain GAD and a monoclonal mouse antibody to the N-terminus of beta-endorphin (3-E7) as primary antisera. PAP-immunohistochemistry revealed GAD-immunoreactivity in the majority of neurons in neostriatum and ACE. OPL-immunoreactivity was observed in numerous neurons in ACE, but only in few neostriatal nerve cells. In double immunofluorescence in the same section OPL- and GAD-immunoreactivity colocalized in few medium size cells in the neostriatum, but in numerous neurons in ACE. The existence of opioid peptide containing GABAergic neurons in ACE and neostriatum is demonstrated.

Amygdala↗
PubMed1983

Immunohistochemical studies on opioid peptides in the human placenta.

The demonstration of the immunoreactive proopiomelanocortin (POMC) peptides beta-endorphin (beta-E), beta-lipotropin (beta-LPH), alpha-melanotropin (alpha-MSH), and corticotropin (ACTH) in the human placenta or in tissue cultures of placental origin using radioimmuno-, bio-, or radioreceptor assay suggested that opioid peptide hormones or their precursors are synthesized in the placenta. In order to test this hypothesis, we tried to localize opioid peptides immunohistochemically. On neighbouring sections of the placenta which were incubated with antisera against beta-E, beta-LPH, alpha-MSH, ACTH, BAM-12 P, BAM-22 P, Heptapeptide, alpha-Neoendorphin and Dynorphin 1-17, the immunoperoxidase method was used. The placenta and the pituitary of perfusion-fixed rats were used for controls. The negative immunohistochemical findings in the human and rat placenta do not support the view that beta-E, beta-LPH, alpha-MSH and ACTH are synthesized in the syncytiotrophoblast of this organ. The site of origin of proopiomelanocortin peptides which are present in the maternal and the fetal plasma most likely is the maternal and fetal pituitary.

Animals↗
PubMed1981

Ultrastructure of a cerebral white matter lesion in a 41-year-old man with Leigh's encephalomyelopathy (LEM).

A brain biopsy taken from a 41-year-old man with Leigh's encephalomyelopathy (LEM) was studied under the electron microscope. The sample of cerebral white matter revealed degenerated oligodendrocytes, reactive astrocytes and scavenger cells filled with miscellaneous debris. Myelin underwent splitting and vacuole formation as well as lamellar and vesicular dissolution. Degenerative and reactive changes were prominent in the axons, many of which were calcified. There was marked fibrous gliosis of the tissue and the extracellular space was enlarged. The small vessels were notably involved; evidence of capillary growth was also found. In sum, the overall picture was one of loss of tissue continuity, loss of axons and loss of myelin, opposite to which stood expansion of the extracellular space, accumulation of filament-filled astroglial process, hypertrophy and hyperplasia of the capillaries and increase of the tissue cellularity. The study has confirmed and defined at the ultrastructural level the well-known histological features of LEM. However, the formal, let alone the causal pathogenesis of the disease remains as obscure as ever.

Adult↗
PubMed1981

Immunohistochemistry of vasopressin, oxytocin and neurophysin in the hypothalamus and extrahypothalamic regions of the human and primate brain.

Vasopressin, oxytocin and neurophysin were localized in the brains and spinal cords of four primates (tree shrew, squirrel monkey, rhesus monkey and human) using antisera to these peptides and the unlabelled antibody-enzyme peroxidase antiperoxidase method. Magnocellular neurons in the hypothalamus stained positively for vasopressin, oxytocin or neurophysin. Parvocellular neurons of the suprachiasmatic nucleus (SCN) stained positively for vasopressin and neurophysin but not for oxytocin, in all four species. Magnocellular oxytocin, vasopressin and neurophysin neurons project to permeable capillaries in the neurohypophysis, as well as to various extrahypothalamic neural target areas including the central amygdala, nucleus of the solitary tract, dorsal motor nucleus of the vagus, lateral reticular nucleus, dorsal horn, central grey and intermediolateral nucleus of the spinal cord. In target areas, terminals contact somata and dendrites. Parvocellular vasopressin and neurophysin neurons of the SCN do not project to the neurohypophysis, and project only to neural target areas, including the lateral septum, mediodorsal thalamus, lateral habenula, mesencephalic central grey, medial amygdala and ventral hippocampus. (Due to the relatively poor tissue preservation in human autopsy specimens not all projections found in the other primates could be confirmed in humans.) These findings confirm and correlate well with previous descriptions made in rodents, and indicate that vasopressin, oxytocin and neurophysin projections to neural targets are present in primates. Peptides released from these projections probably do not enter the bloodstream, but are rather involved in neural mechanisms.

Animals↗
PubMed1981

Relation of neuropeptides to mammalian circumventricular organs.

In summary, highly vascularized CVOs of the mammalian brain are the site of increased vascular permeability for peptides and other molecules which generally do not cross the blood-brain barrier. In the CVOs the blood-brain barrier is shifted from the level of the capillaries to the tight junctions of the oligociliated ependymal cells. The neurohypophysis is the well known target of various peptidergic neuroendocrine neurons. In the neural lobe, peptide hormones from magnocellular neurons are stored and released into the general circulation in the median eminence, releasing and inhibiting hormones enter the hypothalamo-adenohypophyseal portal circulation. The OVLT appears to be an additional vascular outlet for LHRH and somatostatin. In the pineal, no pinealocytes stain positively for arginine-vasotocin; however, occasionally a single neurophysin (vasopressin or oxytocin) fiber has been observed. In the subfornical organ and area postrema which do not appear to have a primary neuroendocrine function, hemo-neural interactions may be important for effects of circulating peptides and other molecules on specific receptors. In the subcommissural organ, which does not have a special vascular permeability, ependymal cells secrete Reissner's fiber, a mucopolysaccharide, whose function in unclear.

Animals↗
PubMed1980

Identification of parvocellular vasopressin and neurophysin neurons in the suprachiasmatic nucleus of a variety of mammals including primates.

The presence of parvocellular vasopressin- and neurophysin-containing neurons in the suprachiasmatic nucleus (SCN) was investigated in 13 mammalian species representing six mammalian orders (marsupials, rodents, lagomorphs, artiodactyls, carnivores, and primates), using specific antisera to vasopressin and neurophysin in the unlabelled antibody=enzyme immunoperoxidase method. In all mammals examined, including man, parvocellular vasopressin and neurophysin neurons were found in the SCN. Only a portion of SCN neurons contain vasopressin and neurophysin, the number varying with species. Cell counts comparing the number of immunoreactive to Nissl-stained neurons showed averages of 17% immunopositive neurons in the rat SCN, and 31% in the human SCN. No oxytocin-containing SCN neurons were observed. These findings suggest that parvocellular vasopressin and neurophysin neurons are widely represented in mammals.

Animals↗
PubMed1979

The distribution of vasopressin-, oxytocin-, and neurophysin-producing neurons in the guinea pig brain. I. The classical hypothalamo-neurophypophyseal system.

The location, cytology and projections of vasopressin-, oxytocin-, and neurophysin-producing neurons in the guinea pig were investigated using specific antisera against vasopressin, oxytocin or neurophysin in the unlabeled antibody enzyme immunoperoxidase method. Light microscopic examination of the neurons of the supraoptic and paraventricular nuclei shows that hormone is transported not only in axons, but also in processes having the characteristics of dendrites. Neurons were found to contain only vasopressin or oxytocin; all neurons containing neurophysin appear to contain either vasopressin or oxytocin. In the neural lobe, vasopressin and oxytocin terminals are intermingled. In the median eminence, vasopressin and oxytocin fibers are intermingled in the internal zone. In a caudal portion of the median eminence, a number of vasopressin and neurophysin (but few oxytocin) axons enter the external zone from the internal zone, and surround portal capillaries. In the supraotic nucleus, vasopressin neurons outnumber oxytocin neurons with a ratio of at least 5:1. The paraventricular nucleus is separated into two distinct groups of neurons, a lateral group consisting of only vasopressin neurons, and a medial group consisting of only oxytocin neurons. In addition to axons passing to the neurohypophysis, a number of axons appear to interconnect the supraoptic and paraventricular nuclei.

Animals↗
PubMed1978

Extrahypothalamic neurophysin-containing perikarya, fiber pathways and fiber clusters in the rat brain.

Immunoreactive neurophysin (Np) is demonstrated by the immunoperoxidase technique not only within neurones of the classical hypothalamo-neurohypophyseal system, but also in extrahypothalamic perikarya and fibers. Np-positive perikarya are found in the triangular nucleus of the septum. Np fibers join the stria terminalis (ST) at the level of the anterior hypothalamus, and course medially in the ST to the central nucleus of the amygdala. Np fibers are found in the brain stem and spinal cord. Fine caliber Np fibers from the suprachiasmatic nucleus ascend to the medial dorsal thalamus and lateral septum. The presence of Np within neurones implies the presence of either vasopressin or oxytocin. Np-positive fibers in extrahypothalamic sites may interact with non-neurosecretory neurones involved in neuroendocrine regulation, or may serve as yet unknown functions.

Animals↗
PubMed1976

[Congenital centronuclear myopathy. Two morphological variants in one family (author's transl)].

This report deals with a family in which the mother and her two daughters suffer from a congenital, slowly progressive neuromuscular disease. Histological, histochemical and ultrastructural observations of the mother's muscle biopsy reveal the characteristics of the centronuclear myopathy. In this case central nuclei and pericentronuclear abnormalities of muscle fibers are found in almost all fibers. Biopsies obtained of the two daughters show alterations especially of type I-fibers, which often are smaller than normal. The presence of these two forms of centronuclear myopathy in one family indicates that these may be only different morphological types of states of one illness. Additionally, other structural findings (rod bodies, core like regions) emphasize the similarities with other congenital slowly progressive myopathies (nemaline myopathy, central core disease).

Adenosine Triphosphatases↗