Search PubMed⌕ Search

Biomedical subjects

J L Morris

Publications and source records attributed to J L Morris.

At least 91 records · Page 5Linked to original sources
PubMed1988

Co-existence of immunoreactivity to neuropeptide Y and vasoactive intestinal peptide in non-noradrenergic axons innervating guinea pig cerebral arteries after sympathectomy.

We have used double-labelling immunofluorescence to examine the coexistence of immunoreactivity (IR) to neuropeptide Y (NPY), tyrosine hydroxylase (TH) and vasoactive intestinal peptide (VIP) in autonomic neurons innervating guinea pig cerebral arteries. In the rostral circle of Willis of control animals. NPY-IR was detected in 86% of axons with TH-IR (noradrenergic) and 18% of VIP-IR (non-noradrenergic) axons. No axons contained both VIP-IR and TH-IR. Ten to 12 days after bilateral removal of the superior cervical ganglia all TH-IR axons had disappeared. The density of VIP-IR axons was unchanged but now 70% of VIP-IR axons contained NPY-IR. These results show that NPY is not exclusively associated with noradrenergic axons in the cerebral vasculature. Furthermore, NPY levels in non-noradrenergic axons increased following sympathetic denervation.

Animals↗
PubMed1988

Treatment of chronic Parkinson's disease with controlled-release carbidopa/levodopa.

Controlled-release carbidopa/levodopa 50/200 (SINEMET CR) and standard carbidopa/levodopa (SINEMET 25/100) were compared in a double-blind, six-month, crossover study involving 21 patients with chronic Parkinson's disease and motor response fluctuations. Daily dosage frequency was significantly reduced with SINEMET CR compared with SINEMET 25/100, while the daily amount of levodopa required with SINEMET CR was significantly greater. No significant differences in disability ratings, motor response fluctuations, or safety were detected during double-blind conditions. In the open-label, dose-finding phase of the study, SINEMET CR was superior to standard SINEMET 25/100 in patient ratings of percent "on" time (good motor function), clinical assessments of motor function, and activities of daily living. This finding resulted from a depreciation of the value of the "old drug" rather than an overestimation of the value of the experimental drug. This double-blind study also suggested that elderly male patients with Parkinson's disease derived the greatest benefit from SINEMET CR.

Aged↗
PubMed1988

Evidence that neuropeptide Y released from noradrenergic axons causes prolonged contraction of the guinea-pig uterine artery.

The participation of neuropeptide Y (NPY) in transmission from sympathetic vasoconstrictor neurons was investigated in the guinea-pig uterine artery, where NPY has been demonstrated immunohistochemically in noradrenergic axons. Exogenous NPY produced long-lasting contractions of isolated arterial segments at low resting tone. Low concentrations of NPY (10(-8)-3 X 10(-7) mol.l-1) were more potent than equimolar concentrations of noradrenaline (NA). NPY produced concentration-dependent desensitization to further application of NPY, but did not affect the magnitude of NA contractions. Trypsin (1.4-2 micrograms.ml-1) reduced NPY-induced contractions by 80-100%, but did not alter NA-induced contractions. Transmural electrical stimulation of arterial segments, after surgical removal of vasodilator axons, produced biphasic contractions which were abolished by guanethidine. Prazosin abolished the fast phase of the neurogenic contraction, leaving a slow contraction with a time course similar to that produced by a low concentration of NPY. The slow contraction was more pronounced at higher frequencies of stimulation (15-20 Hz) than at lower frequencies, and was selectively reduced after desensitization produced by NPY (10(-5) mol.l-1), or after exposure to trypsin. These results suggest that sympathetic vasoconstriction of the guinea-pig uterine artery is produced by release of both NA and NPY from noradrenergic axons.

Animals↗
PubMed1987

Pathway-specific connections between peptide-containing preganglionic and postganglionic neurons in the vagus nerve of the toad (Bufo marinus).

We have examined immunohistochemically the distribution of postganglionic nerve cell bodies and their preganglionic inputs in the vagus nerve of the toad, Bufo marinus. Nerve cell bodies containing immunoreactivity (IR) to somatostatin (SOM) were found at the origin of the oesophago-gastric ramus; these neurons projected to the lung. Cell bodies with SOM-IR also occurred in the intracardiac branches of the vagus, but were absent from the distal segments of the pulmonary and oesophageal rami of the vagus. Cell bodies with IR to vasoactive intestinal peptide (VIP) also occurred at the origin of the oesophago-gastric ramus, but most of these neurons projected to the oesophagus. Most neurons in the distal pulmonary and oesophageal rami were VIP-IR. Some nerve cell bodies in the vagosympathetic trunk and in the intracardiac rami contained both SOM-IR and VIP-IR. Vagal preganglionic nerve fibres with IR both to a somatostatin-like peptide and to substance P were associated exclusively with those postganglionic VIP-IR neurons that projected to the oesophagus. These results provide evidence for highly specific connections between immunohistochemically defined populations of preganglionic and postganglionic neurons in the vagus nerve.

Animals↗
PubMed1987

Increased dopamine-beta-hydroxylase-like immunoreactivity in non-noradrenergic axons supplying the guinea-pig uterine artery after 6-hydroxydopamine treatment.

We have reinvestigated the immunohistochemistry of autonomic axons supplying the guinea-pig uterine artery to determine whether non-noradrenergic paracervical ganglion neurons projecting to the artery contain immunoreactivity to dopamine-beta-hydroxylase (DBH) or somatostatin (SOM) in addition to neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP). In untreated arteries no VIP axons had immunoreactivity to tyrosine hydroxylase (TH), although 9% had immunoreactivity to DBH. Somatostatin immunoreactivity was detected in 25% of non-noradrenergic axons containing NPY and VIP. After in vivo treatment with 6-hydroxydopamine (6-OHDA), noradrenergic axons containing immunoreactivity to NPY, DBH and TH were absent from the adventitia-medial junction. However, 65-70% of the non-noradrenergic axons with NPY and VIP showed DBH immunoreactivity after 6-OHDA. These axons did not show catecholamine fluorescence after incubation with pargyline together with noradrenaline, dopamine or L-DOPA. The number of axons with SOM immunoreactivity increased by 44% after 6-OHDA treatment, but only 24% of SOM axons had DBH immunoreactivity. Surgical destruction of the non-noradrenergic autonomic axons in 6-OHDA-treated animals led to the loss of all DBH immunoreactivity. These results demonstrate that DBH immunoreactivity can be detected in a small proportion of non-noradrenergic axons supplying uterine arteries from untreated animals. After chemical sympathectomy with 6-OHDA, the levels of DBH immunoreactivity in axons of non-noradrenergic neurons increased, and more axons with DBH immunoreactivity were detected. DBH immunoreactivity seemed to increase preferentially in axons with NPY and VIP, but not SOM. The number of NPY, VIP axons containing SOM also increased after 6-OHDA. These findings demonstrate that peripheral neurons containing several different potential neurotransmitters can change their levels of neuropeptides and transmitter-synthesizing enzymes in response to local environmental changes.

Animals↗
PubMed1987

Co-existence of neuropeptides in sympathetic, cranial autonomic and sensory neurons innervating the iris of the guinea-pig.

We have used double-labelling immunofluorescence to identify the peptide content of autonomic and sensory neurons innervating the iris of albino guinea-pigs. Four major classes of neurons were identified on the basis of their distributions, origins and immunohistochemical characteristics. A dense plexus of noradrenergic axons in the constrictor and dilator muscles of the iris originated from the superior cervical ganglion, and contained immunoreactivity (IR) to both neuropeptide Y (NPY) and dynorphin (DYN). The constrictor and dilator muscles were also supplied with a dense plexus of axons with IR to substance P (SP). These axons probably originated from SP-IR nerve cell bodies located along the ciliary nerves, and are almost certainly the same axons as those producing cholinergic pupilloconstriction. The iris was also innervated by unmyelinated, capsaicin-sensitive axons with IR to both SP and calcitonin gene-related peptide. Most of these axons also contained IR to DYN and some were also IR for cholecystokinin. These axons are almost certainly sensory. Axons containing IR to both NPY and vasoactive intestinal peptide (VIP) were common in the ciliary processes, and also formed a sparse plexus near the ciliary margin of the dilator muscle. Following surgical sympathetic denervation these axons showed IR for dopamine-beta-hydroxylase; they seemed to originate from the sphenopalatine ganglion. These results demonstrate that there are well-defined patterns of coexistence of neuropeptides in the autonomic and sensory neurons supplying the iris of guinea-pigs. To understand the physiological roles of these peptides, it will be necessary to consider the possibility of complex interactions between them.

Animals↗
PubMed1987

Neuronal colocalization of peptides, catecholamines, and catecholamine-synthesizing enzymes in guinea pig paracervical ganglia.

The patterns of colocalization of neuropeptides, catecholamines, and catecholamine-synthesizing enzymes were examined in principal neurons and nerve terminals in guinea pig paracervical ganglia using a double-labeling immunohistochemical procedure. A small proportion of nerve cell bodies (less than 10%) had the characteristics of catecholamine-synthesizing neurons and presumably were noradrenergic. Another 50% of the nerve cell bodies contained immunoreactivity (IR) to dopamine-beta-hydroxylase (DBH), but did not have any other characteristics of noradrenergic neurons; they did not contain detectable catecholamines, or IR to dopa decarboxylase (DDC) or tyrosine (TH) hydroxylase, nor did they take up exogenous catecholamines. Half of the catecholamine neurons had neuropeptide Y (NPY)-IR, and a small number (0.5% total neurons) had somatostatin (Som)-IR. Most of the non-noradrenergic neurons with DBH-IR (40-50% total neurons) contained IR for dynorphin (Dyn), NPY, and vasoactive intestinal peptide (VIP), and about half of them (20-25% total) also contained Som-IR. Ten to twenty percent of neurons contained IR to Som, but not to any other antigen examined here. Nerve terminals with substance P (SP)-IR or enkephalin (Enk)-IR were prominent in all ganglia. SP-IR fibers formed dense baskets only around those neurons with DBH/Dyn/NPY/VIP (+/- Som)-IR, while fibers with very bright Enk-IR were associated selectively with those neurons with Som-IR alone. In addition, most TH-IR nerve cell bodies were surrounded by NPY-IR varicose nerve fibers. In conclusion, this analysis of combinations of peptides and enzymes contained in principal neurons of the paracervical ganglia allows us to identify as many as 11 different neuron populations. The functional significance of the presence of the same neuropeptide (e.g., NPY) in different neuron populations is as yet unknown. Some of these classes of neurons are associated specifically with immunohistochemically distinct types of presynaptic nerve fibers, which suggests that different immunohistochemically defined classes of neurons represent different functional pathways.

Animals↗
PubMed1986

Neuropeptide Y-like immunoreactivity is absent from most perivascular noradrenergic axons in a marsupial, the brush-tailed possum.

Noradrenergic perivascular axons were demonstrated in all systemic arteries and veins of a marsupial, the brush-tailed possum (Trichosurus vulpecula), by a catecholamine fluorescence procedure and with antisera directed against the catecholamine-synthesizing enzymes tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (D beta H). Perivascular axons with neuropeptide Y-like immunoreactivity (NPY-LI) were not found in most systemic arteries and veins using antisera which recognize NPY and other members of the pancreatic polypeptide family in diverse vertebrate species. The exceptions were the renal, coeliac, main mesenteric and iliac arteries, where up to 50% of axons with TH-LI or D beta H-LI also showed NPY-LI with two of the 4 antisera used. No noradrenergic nerve cell bodies in thoracic sympathetic ganglia had NPY-LI, whilst 3% of noradrenergic nerve cell bodies in lumbar sympathetic chain ganglia had weak NPY-LI. This marsupial is the first vertebrate species found to date in which the majority of perivascular noradrenergic axons do not contain NPY-LI. If these axons contain an as yet unidentified neuropeptide, it is unlikely to be closely related to NPY.

Animals↗
PubMed1986

Proliferation of arteriovenous anastomoses in the developing rabbit ear is enhanced after denervation.

The innervation of the rabbit ear vasculature by noradrenergic and substance P-immunoreactive (SP-IR) nerves was investigated in both young and adult animals. All vascular segments were supplied by both noradrenergic and SP-IR nerves. In the ear margins, the arteriovenous anastomoses (AVAs) were more densely innervated than other vessels. In general, the density of both noradrenergic and SP-IR nerves increased with age until 10-12 weeks postnatum. The ear vasculature was denervated in young rabbits to test whether the normal proliferation of AVAs in the growing ear was altered in the absence of nerves. Surgical resection of all auricular nerve trunks except the auricular branch of the auriculo-temporal nerve, and removal of the ipsilateral superior cervical ganglion in 10- to 12-day-old rabbits left the ear devoid of both noradrenergic and SP-IR nerves for at least four weeks. Repeated administration of 6-hydroxydopamine (6-OHDA) to young rabbits produced degeneration of noradrenergic terminal axons, but preterminal nerve trunks survived. SP-IR nerves did not appear to be affected by 6-OHDA. These denervation regimes resulted in a 1.5- to 2-fold increase in the number of AVAs formed in the growing ear. Surgical denervation and 6-OHDA treatment also led to retarded growth of the media of the central ear artery, but this effect of 6-OHDA was probably not due to a specific action on vascular smooth muscle. Surgical resection of most of the dorsal auricular nerves in adult rabbits did not affect AVA density. Large differences in AVA density were apparent between groups of control animals from different parts of the country, or groups examined at different times of the year. These results demonstrate that the labile nature of AVAs in the rabbit ear can result in considerable variability in the absolute number of AVAs and suggest that both intrinsic and extrinsic factors may influence development of the microvasculature.

Animals↗
PubMed1986

Innervation of the large arteries and heart of the toad (Bufo marinus) by adrenergic and peptide-containing neurons.

The innervation of the major arteries and heart of the toad (Bufo marinus) was examined by use of glyoxylic acid-induced catecholamine fluorescence and peptide immunohistochemistry. All arteries possessed a moderate to dense plexus of adrenergic axons, which also showed neuropeptide Y-like immunoreactivity (NPY-LI). Some adrenergic axons in the intracardiac vagal trunks showed NPY-LI, but the varicose adrenergic axons innervating the cardiac muscle of the atria and ventricle, and the coronary blood vessels did not display NPY-LI. About half of the nerve cell bodies in the anterior sympathetic chain ganglia with dopamine-beta-hydroxylase-LI (DBH-LI) also contained NPY-LI. The nerve cell bodies with DBH-LI alone were generally larger (median diameter 30 micron) than those with both DBH-LI and NPY-LI (median diameter 20 micron). Some cell bodies showing DBH-LI alone were surrounded by boutons with NPY-LI but not DBH-LI. Axons that displayed simultaneously both substance P-LI (SP-LI) and calcitonin gene-related peptide-LI (CGRP-LI) also formed a plexus around all arteries studied, being particularly dense around the mesenteric and pulmonary arteries. These axons are most likely sensory since SP-LI was reduced by capsaicin treatment, and nerve cell bodies with both SP-LI and CGRP-LI were found in dorsal root ganglia and the vagal ganglion. A dense plexus of axons showing somatostatin-LI was located around the pulmonary artery and its main intrapulmonary branches. A few nerves with vasoactive intestinal polypeptide-LI were found around the dorsal aorta and pulmonary artery. No perivascular nerves with enkephalin-LI were observed. Reversed-phase, high-pressure liquid chromatography of acid extracts of the large arteries showed that the major peaks of NPY-LI and SP-LI co-eluted with porcine NPY (1-36) and synthetic SP (1-11), respectively. Thus, the location and structure of these peptides in perivascular nerves has been highly conserved during vertebrate evolution.

Adrenergic Fibers↗
PubMed1986

Partial depletion of neuropeptide Y from noradrenergic perivascular and cardiac axons by 6-hydroxydopamine and reserpine.

The effects of 6-hydroxydopamine (6-OHDA) and reserpine on the storage of neuropeptide Y (NPY) in noradrenergic cardiovascular nerves were examined with both immunohistochemistry and radioimmunoassay (RIA). Immunohistochemical double-labelling techniques demonstrated that NPY was located only in noradrenergic axons in the guinea-pig carotid artery, mitral valve, thoracic inferior vena cava, thoracic aorta, superior mesenteric artery and small saphenous vein. Treatment with 6-OHDA in vivo eliminated noradrenergic, NPY-containing axon terminals from all tissues, but preterminal axons were still prominent in the superior mesenteric artery. The greatest depletion of NPY detected by RIA after 6-OHDA treatment was found in tissues with a predominance of terminal noradrenergic axons, such as the small saphenous vein, whereas NPY accumulating in preterminal axons masked the loss of NPY from terminal axons in the superior mesenteric artery. After treatment with doses of reserpine that led to a rapid depletion of noradrenaline (NA) from perivascular nerves, NPY was still detected histochemically at all times although levels sometimes appeared to be reduced. RIA demonstrated that the partial depletion of NPY after reserpine consisted of a rapid phase seen in the vena cava and saphenous vein after the highest doses, and a slower phase of NPY depletion from all tissues after all doses of reserpine. The greatest depletion of NPY from terminal axons by reserpine (in small saphenous vein) was 85-90%. These results demonstrate that some NPY can be stored in noradrenergic perivascular axons in the absence of noradrenaline, but that partial depletion of NPY from axon terminals results when NA stores are depleted by reserpine. The variation in extent of NPY depletion between tissues after drug treatments can be explained by variation in the ratio of preterminal to terminal axons.

Animals↗
PubMed1986

Biomechanical implications of hammertoe deformities.

A discussion of hammertoe, mallet toe, and clawtoe has been presented. Their relationship to the various pathomechanic structural deformities has also been discussed. The practitioner must consider the biomechanics of foot function whenever surgery is planned.

Biomechanical Phenomena↗
PubMed1985

Co-localization of neuropeptide Y, vasoactive intestinal polypeptide and dynorphin in non-noradrenergic axons of the guinea pig uterine artery.

Two major populations of perivascular axons containing immunoreactivity to neuropeptide Y (NPY) have been revealed in the main uterine artery of the guinea pig by immunohistochemical procedures which allow the simultaneous visualization of two antigens. One population contained immunoreactivity to dopamine-beta-hydroxylase (D beta H) and was presumably noradrenergic. The other main population of axons with NPY-like immunoreactivity (NPY-LI) did not have D beta H-like immunoreactivity (D beta H-LI) and was presumably non-noradrenergic. These non-noradrenergic axons also contained immunoreactivity to vasoactive intestinal polypeptide (VIP) and dynorphin (DYN). Indeed, nearly all axons with VIP-LI also contained NPY-LI and DYN-like immunoreactivity (DYN-LI). NPY constricted the uterine artery perfused in vitro, whilst VIP dilated uterine arteries preconstricted with noradrenaline or NPY. Thus, we have evidence for the coexistence of a vasoconstrictor peptide and a vasodilator peptide in the same non-noradrenergic perivascular axons, which also contain an opioid peptide, dynorphin.

Animals↗
PubMed1985

To report or not to report. Physicians' attitudes toward discipline and child abuse.

Interviews were conducted with 58 physicians to ascertain what factors influenced their reporting of child abuse. When physicians were presented with sample cases of injured children, factors that influenced their decision to report suspected abuse included their attitudes toward physical discipline, seriousness of the injury, presence of other injuries, their familiarity with the family, appropriate parental concern, compatibility of the history and physical examination findings, and the child's behavior. Results indicated that inappropriate discipline was usually not equated with reportable child abuse. Physicians believed that abuse is not often reported because of its low incidence in the private practice setting, the fear of losing patients, the need for certainty, and the lack of confidence in community agencies. These beliefs may conflict with the welfare of young patients.

Attitude of Health Personnel↗