PubMed Health⌕ Search

Biomedical subjects

J K Moore

Publications and source records attributed to J K Moore.

At least 73 records · Page 4Linked to original sources
PubMed1990

Differences in in vitro growth of epithelium from inflammatory and developmental odontogenic cysts.

Ninety-three odontogenic cysts, 42 of inflammatory and 51 of developmental origin, were grown in vitro from explants and/or cell suspensions. There was little difference in the success rate of culturing epithelium from explants of dentigerous cysts (N = 28) or odontogenic keratocysts (N = 23) (approximately 75% and 87%, respectively) and the dentigerous cyst grew particularly well from suspensions (N = 11) (91%) compared with the keratocyst (N = 19) (58%). Epithelium from developmental odontogenic cysts grew much better in vitro than did cysts of inflammatory origin (56 to 58% from explants and 19 to 25% from suspension). From this work there is little evidence to support previous statements that the dentigerous cyst cannot be grown from explants, or that the odontogenic keratocyst has 'aggressive' growth characteristics.

Cells, Cultured↗
PubMed1989

Nigrotectal projection to the inferior colliculus: horseradish peroxidase transport and tyrosine hydroxylase immunohistochemical studies in rats, cats, and bats.

The present study investigated descending projections from the substantia nigra to the auditory tectum. Small (0.02-0.05 microliters) injections of a 30-60% aqueous solution of horseradish peroxidase (HRP) were made unilaterally into the inferior colliculus in rats, cats, and bats (Eptesicus fuscus). Tissue blocks including the substantia nigra, superior colliculus, and inferior colliculus were removed, sectioned, and processed for visualization of HRP. Results show that the substantia nigra, pars lateralis, projects to the inferior colliculus ipsilaterally. In addition, retrogradely labeled cells are found dorsal to the pars lateralis, in a column within the lateral tegmental area of the midbrain. Analysis of injection sites suggests that the principal target of this nigral projection is the dorsal and rostral pericentral region of the inferior colliculus. Immunohistochemical studies with an antibody to tyrosine hydroxylase demonstrate catecholaminergic neurons within the pars lateralis and lateral tegmentum that are similar in location and morphology to one class of HRP retrogradely labeled cells within these structures. These immunohistochemical studies also demonstrate a plexus of fine, varicose tyrosine hydroxylase-positive axons in the rostral pericentral region of the colliculus. The presence of this nigrotectal projection to the inferior colliculus is discussed in relation to its possible role in the control of acousticomotor behavior.

Animals↗
PubMed1989

Applications of a method for setting air quality standards based on epidemiological data.

A method for setting air quality standards for long-term cumulative exposures of a population based on epidemiological studies has been developed. It uses exposure estimates interpolated from monitoring stations to zip code centroids, each month applied to zip code by month residence histories of the population. Two alternative cumulative exposure indices are used--hours in excess of a threshold, and the sum of concentrations above a threshold. The indices are then used with multiple logistic regression models for the health outcome data to form dose response curves for relative risk, adjusting for covariates. These curves are useful for determination of at what exposure amounts and threshold levels, effects which have both statistical and public health significance begin to occur. The method is applied to a ten year follow-up of a sub cohort of 7,343 members of the National Cancer Institute-funded Adventist Health Study. Up to 20 years of residence history was available. Analysis for prevalence of symptoms was conducted for four air pollutants--total oxidants, sulfur dioxide, nitrogen dioxide, and total suspended particulates. For each pollutant, cumulated exposures were calculated above each of five different thresholds. Statistically significant effects were noted for total suspended particulates, total oxidants, sulfur dioxide, past and passive smoking.

Air Pollution↗
PubMed1989

DNA synthesis in Langerhans' cells of mouse ear epithelium revealed by tritiated thymidine autoradiography and histochemical staining for non-specific esterase and beta-glucuronidase activity.

The proportion of Langerhans' cells in DNA synthesis in normal mouse skin was assessed by combining tritiated thymidine [3H]TdR autoradiography with enzyme histochemistry. After injection of [3H]TdR, ear skin was treated in two ways. Epithelial sheet preparations were stained for the presence of non-specific esterase and cytospin preparations of epithelial cell suspensions were stained for beta-glucuronidase activity. The labelling index (+/- SE mean) for cytospins, 40 min after injecting [3H]TdR, was 1.6 +/- 0.15%, doubling to 3-4% from 7-17 days after injection. The sheet preparations showed the proportion of label attributable to paired Langerhans' cells rising from 18% at 40 min after injection, to approximately 45%, on days 1-4 after injection. These results suggest that the proliferation of Langerhans' cells in normal mouse skin might be higher than was previously thought to be the case.

Animals↗
PubMed1988

Anaesthetic experience--the view from below.

The anaesthetic experience gained during general professional training is reviewed, indicating the spectrum of patients managed and training received. The experience gained was broadly in line with the guidelines recommended by the Faculty of Anaesthetists. The advantage of movement between hospitals at a junior level is noted, as is the value of a case record book, for both the individual and the Anaesthetic Department.

Anesthesiology↗
PubMed1988

Macroglossia and posterior fossa disease.

We describe five cases of macroglossia in patients with posterior fossa disease and suggest that the primary mechanism is neurogenically determined rather than one of vascular obstruction or local trauma.

Adult↗
PubMed1987

Glutamic acid decarboxylase-like immunoreactivity in brainstem auditory nuclei of the rat.

The distribution of GABA-producing neurons in the brainstem auditory nuclei of the rat was investigated immunohistochemically by using an antibody to glutamic acid decarboxylase (GAD). In the cochlear nuclei, GAD immunoreactive neurons are present only in the superficial granular and molecular layers, whereas terminals are found in all subdivisions of the nuclei and are particularly dense surrounding large spherical cells and one type of stellate cell. In the superior olivary complex, GAD immunoreactive neurons are located in the lateral olivary nucleus and throughout the periolivary region. Immunoreactive terminals are distributed along dendrites of principal cells of the medial and lateral olivary nuclei and are clustered around somata of globular neurons of the nucleus of the trapezoid body. An extremely dense band of immunoreactive somata and terminals is present along the ventral edge of the olivary complex. The ventral, intermediate, and dorsal nuclei of the lateral lemniscus contain small fusiform GAD-immunoreactive neurons and a moderately dense plexus of immunoreactive terminals. The inferior colliculus contains a large population of GAD-immunoreactive perikarya and an extremely dense accumulation of immunoreactive terminals in the central, dorsomedial, and external nuclei. These observations indicate that GABA systems are involved in function at all levels of the brainstem auditory pathway.

Animals↗
PubMed1987

The human auditory brain stem: a comparative view.

This study compares human brain stem auditory centers with those of the cat in terms of their topography and cytoarchitecture. Graphic reconstructions of the brain stem pathway illustrate differences in configuration of human auditory centers, such as mediolateral elongation of the cochlear nuclei and rostral prolongation of the superior olivary complex. Greater human brain stem size creates a considerably longer auditory pathway: the distance traversed by axons passing from the cochlear nuclei to the ipsilateral inferior colliculus is approximately 14 mm in the cat and 35 mm in man, while the distance to the contralateral colliculus is about 22 mm in the cat and 46 mm in man. Neuronal groups which are well developed in the human brain stem are the populations of large relay neurons in the cochlear nuclei, the medial olivary nucleus, periolivary region, dorsal nucleus of the lateral lemniscus, and inferior colliculus. In contrast, a number of nuclei and cell groups are very poorly developed or absent in the human auditory system: these include several types of small neurons in the cochlear nuclei, the lateral olivary nucleus, nucleus of the trapezoid body, and ventral nucleus of the lateral lemniscus. The functional implications of these changes are discussed.

Animals↗
PubMed1987

The human auditory brain stem as a generator of auditory evoked potentials.

Data on the size, location, and orientation of human brain stem auditory nuclei are discussed here from the point of view of the potential role of these structures in generation of the brain stem auditory evoked response. Due to reduction in size of several nuclei in the human brain stem, the structures most likely to be generators of far-field potentials are the cochlear nuclei, medial olivary nuclei, dorsal lemniscal nuclei, inferior colliculi, and their axonal projections. Consideration of the anatomy of the human auditory brain stem pathway forms the basis for a model of generation of auditory evoked potentials.

Animals↗
PubMed1987

Postoperative complications of dystrophia myotonica.

A 44-year-old man with known mitral stenosis presented for minor surgery. Anaesthesia was induced with fentanyl, droperidol and etomidate and maintained with nitrous oxide, oxygen and vecuronium. Surgery and anaesthesia were uneventful but the postoperative course was stormy, with respiratory arrest, Haemophilus pneumonia, refractory cardiac dysrhythmias and gastrointestinal atony. A diagnosis of dystrophia myotonica was made after 3 weeks in the intensive care unit, and he spent 6 weeks in hospital. A high index of suspicion for this disease must be maintained and intensive care facilities and monitoring should be available for all procedures.

Adult↗
PubMed1987

Awareness during bronchoscopy.

The purpose of the study was to assess the incidence of awareness during bronchoscopy and to evaluate the effectiveness of auditory random noise in preventing awareness. All patients were unpremedicated and underwent elective bronchoscopy under thiopentone-suxamethonium anaesthesia. Half the patients received auditory random noise preoperatively. Patients were interviewed postoperatively and the incidence of awareness and dreaming assessed. Eleven patients described awareness, of whom three had received random noise. No relation with awareness could be shown with the age and sex of the patient, nor was awareness related to the dosage of thiopentone. Awareness was associated with a short time interval between removal of the bronchoscope and response to command. Awareness is still an important problem in anaesthesia and the use of random noise stimulation to block auditory input of relevance to the patient merits further investigation.

Adolescent↗
PubMed1986

Raynaud's phenomenon precipitated by blood transfusion.

A patient undergoing surgery with spinal anaesthesia received a transfusion of concentrated red cells. Whenever the rate of blood transfusion reached a certain critical value, the symptoms and signs of Raynaud's phenomenon appeared in the hand distal to the site of the intravenous cannula. Possible causes of this transfusion-induced vasospasm are discussed.

Anesthesia, Spinal↗
PubMed1985

Sheet preparations of the stratum granulosum from mammalian skin and oral epithelium.

Acetic acid has been used to obtain sheet preparations of the stratum granulosum from epidermis and oral epithelium of mouse, rat, hamster and man. Clear differences exist in the appearance of nuclei and keratohyalin granules and in the extent of cell overlapping. In the ventral surface of mouse tongue, the number of granular cells in a sheet preparation is relatively constant (average +/- S.D. = 1633 +/- 160/mm2). Cell suspensions show a greater variation in the area and maximum diameter of the cells in ventral tongue compared to mouse ear epidermis. As might be expected, this is reflected in the pattern of stacking of suprabasal cells into discrete columns in ear, but not in ventral tongue epithelium. The ratio of granular to basal cells for different sites and species is fairly constant, with an average of approximately 10:1. The pattern of nuclear breakdown can be followed, beginning in the middle of the nucleus and gradually extending outwards, often in an irregular manner until the entire nucleus is removed.

Acetates↗
PubMed1984

Evolution of myelin sheaths: both lamprey and hagfish lack myelin.

Modern views of agnathan phylogeny consider Petromyzoniformes and Myxiniformes to belong to distinct classes that diverged from a common ancestor at a remote period, perhaps in the lower Cambrian, greater than 600 million years ago. Both are more primitive than elasmobranchs, holocephalans and bony fishes. Myelin is well developed in elasmobranchs and other fishes but was reported to be lacking in the spinal cord of lampreys. In order to search further for possible early myelin in some part of the nervous system of one of the agnathan stems, or for further evidence that it first appeared in chondrichthians, we extended the sampling to many parts of the brain and cord of hagfish. Transmission electron microscopy was used as a nearly ideal criterion. We find no trace or forerunner of the spiral, multilaminate glial wrapping. Many axons are embedded within one or more glial cells, like unmyelinated fibers in other vertebrates, or lie contiguously in bundles without an obviously complete glial investment. True myelin must be presumed to have been invented within the vertebrates, in ancestors of the living cartilaginous fishes after the agnathans branched from the vertebrate stem.

Animals↗