Biomedical subjects

W H Pilcher

Publications and source records attributed to W H Pilcher.

29 records · Page 2Linked to original sources

PubMed1988

Immunocytochemical localization of pro-opiomelanocortin neurons in human brain areas subserving stimulation analgesia.

The distribution of pro-opiomelanocortin (beta-endorphin, adrenocorticotropic hormone, and 16-K) neurons and fiber projections was evaluated immunocytochemically in 50-mu thick cryostat sections of human diencephalon and midbrain. Specific attention was focused upon regions in which deep brain stimulation has been most effective in the relief of selected chronic pain syndromes. This study revealed a remarkable, nearly point-to-point correlation between clinically effective stimulation sites and the distribution of pro-opiomelanocortin fibers in the human brain. Of particular interest was the dense innervation of the periventricular stratum along the third ventricle, the parafascicular centromedian region of the thalamus, and the periaqueductal gray matter of the midbrain. This study provides anatomical support for the hypothesis that beta-endorphin-containing neuronal systems may contribute to stimulation analgesia in the human.

Adolescent↗

PubMed1985

Anatomy of the corticotropin-releasing factor and opiomelanocortin systems of the brain.

Using antiserums generated against the neuropeptides corticotropin-releasing factor (CRF), beta-endorphin, and adrenocorticotropin, we have immunocytochemically mapped the organization of these hormones throughout the brain. The distribution of CRF perikarya is widespread throughout the forebrain, brain stem, and spinal cord. The central opiomelanocortin system is represented by two separate pools of neuronal perikarya: the hypothalamic arcuate pool, and the medullary (nucleus tractus solitarius) pool. From these groups fibers distribute widely throughout forebrain and brain stem. A conspicuous codistribution pattern exists between the CRF perikarya and opiomelanocortin fibers. Analysis of these systems within the brain stem and spinal cord reveals innervation and distribution patterns within regions containing catecholamine systems, areas associated with regulation of sympathetic and parasympathetic outflow, cardiovascular and respiratory homeostatic centers, and regions associated with stress, autonomic homeostasis, and pain modulation. By virtue of these extensive brain-stem distributions, it is suggested that an anatomical substrate exists for participation of these peptide systems in the integration of certain autonomic, visceral, and homeostatic mechanisms.

Adrenocorticotropic Hormone↗

PubMed1985

Pulmonary platelet trapping induced by beta-endorphin injection in the cerebrospinal fluid in dogs.

The effect of beta-endorphin injected into either the lateral ventricle or the cisterna magna on blood pressure, heart rate, peripheral platelet and leukocyte counts, hematocrit levels, catecholamines, and pulmonary platelet trapping was studied. The effect of endotoxin on the endogenous opiocortin system was also investigated. Injection of beta-endorphin caused a significant decrease in blood pressure, bradycardia, and pulmonary platelet trapping. beta-Endorphin had no effect on peripheral platelet and leukocyte counts, catecholamines, or hematocrit levels. Endotoxin shock caused a marked rise in circulating beta-endorphin and a decrease in cerebrospinal fluid beta-endorphin. Our results confirm that endotoxin shock activates the opiocortin system, and we suggest that the endorphins may participate in the evolution of the lung injury seen in septic shock.

Animals↗

PubMed1984

Co-localization of CRF-ir perikarya and ACTH-ir fibers in rat brain.

The distribution of corticotropin-releasing factor immunoreactive (CRF-ir) perikarya and ACTH-ir fibers was examined immunocytochemically, in adjacent sections, in the forebrain and brainstem of the rat. Throughout the nervous system, a remarkable concordance of localization of these neuropeptide systems was noted. Both ACTH-ir fibers and CRF-ir perikarya were conjointly distributed within discrete hypothalamic, limbic and brainstem/autonomic regions previously demonstrated to contain opiate receptors and opiocortin (beta-endorphin, beta-LPH, ACTH) fibers. In view of the demonstrated interactions of CRF with the peripheral (pituitary) opiocortin system, these data suggest the possibility of a similar relationship of CRF and opiocortin systems in the central nervous system as well.

Adrenocorticotropic Hormone↗

PubMed1983

Immunocytochemical localization of ACTH perikarya in nucleus tractus solitarius: evidence for a second opiocortin neuronal system.

Immunocytochemical localization of ACTH-opiocortin perikarya was demonstrated in the medulla of colchicine-treated rat. Neuronal cell bodies and fibers containing ACTH-immunoreactivity were abundant in the caudal region of the nucleus tractus solitarius, specifically within pars commisuralis. Location of these opiocortin neurons within the nucleus tractus solitarius provides additional evidence for a role of these peptides in cardiovascular functions.

Adrenocorticotropic Hormone↗

PubMed1982

The distribution of enkephalin in the mediobasal hypothalamus of the mouse brain: effects of neonatal administration of MSG.

The immunocytochemical distribution of the pentapeptides, methionine- and leucine-enkephalin (Enk) were examined in the mediobasal hypothalamus of control mice with a neurotoxic lesion of the arcuate nucleus due to neonatal treatment of monosodium glutamate (MSG). In control mice immunoreactive Enk cells and fibers were present in the arcuate nucleus. Enk fibers were found in the subependymal, internal and external layers of the median eminence. At 60 days of age, mice receiving neonatal injections of MSG displayed symptoms of neuroendocrine deficiencies. Histochemical methods revealed a loss of Enk immunoreactivity from the arcuate nucleus and all layers of the median eminence. These results suggest that the lack of Enk cells and fibers in the mediobasal hypothalamus of MSG-treated animals is partially responsible for the endocrine dysfunctions exhibited by these animals.

Animals↗

PubMed1982

Distribution of somatostatin in the mouse brain: effects of neonatal MSG treatment.

Immunocytochemical analysis using antisera generated against the brain peptide somatostatin (SRIF) was examined in the brain of normal mice and in mice with chemical lesions of the arcuate nucleus produced neonatally by the administration of monosodium glutamate (MSG). In the normal mouse brain, SRIF immunoreactivity was seen in perikarya of the preoptic and hypothalamic periventricular nuclei. The normal distribution of SRIF fibers was apparent in several hypothalamic nuclei including the arcuate nucleus and in the internal and external zones of the median eminence. Extrahypothalamic sites of SRIF immunoreactive neurons and fibers were also observed throughout the telencephalon. At 60 days of age, certain neuroendocrine deficiencies, including growth parameters and obesity, were apparent in MSG-treated newborn mice. Analysis of SRIF projections in the brain of MSG-treated mice demonstrated a neurotoxic effect on arcuate neurons and a loss of SRIF projections to this region as well. Other components of the SRIF system in brain appeared unaffected. SRIF fibers of the arcuate region seem to originate from neuronal perikarya of the periventricular nucleus suggesting that MSG-induced endocrine deficiencies may be due to SRIF interactions at the level of the arcuate nucleus.

Animals↗

PubMedDate not supplied

Differential sensitivity of hypothalamic and medullary opiocortin and tyrosine hydroxylase neurons to the neurotoxic effects of monosodium glutamate (MSG).

The distribution of opiocortin- (OP-ir) and tyrosine hydroxylase-immunoreactive (TH-ir) perikarya was examined immunocytochemically in rats treated neonatally with the neurotoxin monosodium glutamate (MSG). While OP-ir and TH-ir perikarya were eliminated in the arcuate nucleus in treated animals, the OP-ir and TH-ir cell groups of the nucleus tractus solitarius and contiguous medullary regions were unaffected. This selective elimination of arcuate neurons permitted us to examine specifically the fiber projections of the medullary OP-ir perikarya in treated animals. This revealed a preferential distribution of delicate fibers originating in NTS, to discrete medullary and pontine areas. In control animals, these same terminal fields appeared to be more densely populated with an additional population of thicker OP-ir fibers, suggesting the possibility of a shared innervation of these brainstem regions by both hypothalamic and medullary OP-ir neurons.

Animals↗

PubMedDate not supplied

Low initial tau phosphorylation in human brain biopsy samples.

A rapid reversible tau phosphorylation at Ser 396/404 was observed in adult human cortical biopsy tissue and rat primary cortical cell cultures. Tau phosphorylation increased usually during the first 20-30 min in phosphate-buffered saline, followed by a decrease. The time course of tau phosphorylation and dephosphorylation in biopsy tissue could be lengthened by culturing in defined, oxygenated medium, instead of in phosphate-buffered saline. Phosphorylation of total protein in biopsy tissue occurred in two phases, with peaks at 30 and 90 min. The first peak of total protein phosphorylation coincided with the peak of tau phosphorylation, although both the first and second peaks of total protein phosphorylation coincided with the first and second peaks of neurofilament-H phosphorylation.

Adolescent↗

PubMedDate not supplied

Epilepsy in schizencephaly: abnormal cortical organization studied by somatosensory evoked potentials.

Median nerve short-latency somatosensory evoked potentials (MN-SSEP) are recorded from the scalp to assess parietal lobe function and from the cortex to identify primary sensory and motor areas before epilepsy surgery. Nevertheless, the origins of many of the MN-SSEP waveforms and the reliability of this technique for localizing the central sulcus are not definitively known. We studied a child with a unilateral, closed, right parietal schizencephalic cleft and frequent simple partial seizures before the child underwent cortical resection. The sensory examination, neuroimaging, and electrical brain stimulation findings indicated a normal thalamus and an abnormal parietal lobe. Scalp-recorded MN-SSEPs showed intact widespread N18 potentials bilaterally, but absent right, although normal left parietal N20 and P27 waveforms. Cortically recorded MN-SSEPs could not localize the central sulcus owing to an absence of the expected negative potential over the right postcentral gyrus and the presence of waves with abnormal latencies over the precentral cortex. These findings suggest that: (a) the N18 potential probably originates at or below the level of the thalamus, (b) the N20 and P27 peaks are most likely generated by parietal cortex or white matter, and (c) cortically recorded MN-SSEPs can fail to localize the central sulcus before epilepsy surgery when congenital anomalies exist in the parietal lobe.

Adolescent↗

PubMedDate not supplied

Cervical spinal meningioma with unusual MR contrast enhancement.

A 16-year-old girl had progressive neck pain and weakness in the left hand. MR images showed a dumbbell-shaped spinal tumor with a prominently enhancing intradural component and a minimally enhancing extradural component. Pathologic examination revealed a meningioma with an intradural transitional component and an extradural syncytial component. The tumor showed no significant cystic change or necrosis.

Adolescent↗