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Biomedical subjects

M H Cooper

Publications and source records attributed to M H Cooper.

At least 55 records · Page 3Linked to original sources
PubMed1983

Increases in fluoride, calcium, and phosphate in dental plaque resulting from the use of a mineralizing mouthrinse containing urea and monofluorophosphate.

A mouthrinse used ten times over a four-day period increased the concentration of acid-extractable fluoride in immature plaque by 320%, calcium by 190%, and phosphate by 97%. Corresponding increases in mature plaque were smaller, yet significant. Diffusion of the ions from plaque was restricted, and hence a prolonged caries-inhibitory effect can be expected.

Calcium↗
PubMed1981

The hypoglossal nucleus of the primate: a Golgi study.

The neurons of the hypoglossal nucleus were examined in Golgi preparations of adult macaque and squirrel monkeys. Two distinct types of neurons were found. The first type was a large multipolar cell which was typical of the majority of the neurons of the nucleus. Its soma ranged in size from 18 to 50 micrometers and numerous dendrites emerged from it. The dendritic spread of these neurons was within the ipsilateral nucleus, across the midline into the contralateral hypoglossal nucleus, or out into the adjacent reticular formation. The second type of neuron was a small cell. The soma of this neuron was oval in shape, measured less than 20 micrometers in its largest diameter, and gave off only two or three dendrites which remained within the nucleus.

Animals↗
PubMed1981

Contralateral laryngoplasty after supraglottic laryngectomy with vertical extension.

Eight patients with supraglottic carcinoma extending onto an arytenoid or true vocal cord have undergone supraglottic laryngectomy with vertical extension including the resection of an arytenoid. In these patients, the contralateral superior thyroid cornua was used to reconstruct the resulting defect. In this technique, the thyroid cornua is mobilized and green-stick fractured across the posterior commissure, maintaining its blood supply by leaving the inferior and middle pharyngeal constrictor attached. This muscle-cartilage pedicle flap provides bulk for the posterior glottis and can be anchored anteriorly to form the framework for a new vocal cord. Hypopharyngeal and pyriform sinus mucosa is then mobilized to cover the newly reconstructed hemilarynx. This reconstruction has provided a competent glottis with a good vocal baffle in every patient in this series. Preservation of airway, voice, and laryngeal sphincter is comparable with that achieved after routine supraglottic laryngectomy without resection of an arytenoid. Using this technique, the surgeon can rely on a pedicle graft with surprising accessibility, bulk, and reach.

Aged↗
PubMed1981

Caries progression in primary molars: 24-month results from a minimal treatment programme.

A 2-stage topical treatment regimen (AgF followed by SnF2) was used in an attempt to limit caries progression in the primary molars of children participating in a minimal treatment programme. The children lived in an isolated community in western New South Wales (fluoride in water less than 0.2 parts/10(6)) and were from a low socioeconomic background. The progression, over a 24-month period, of 281 established lesions in the approximal and occlusal surfaces of primary molars in 54 subjects (mean age 7.0 years) was determined from bitewing radiographs. Of the lesions studied, the majority (69%) were in dentine at baseline. At 24 months, 74% of the approximal surface lesions and 90% of the occlusal surface lesions that were in enamel at baseline remained unchanged. The greatest change occurred in the approximal surface lesions that were within 1 mm of the pulp at baseline. Only 35% of the lesions required any treatment other than topical metal fluoride therapy during the 24-month period.

Child↗
PubMed1981

Oral health of Australian children using surface and artesian water supplies.

Oral health parameters were compared for 6--8 and 10--11-year-old children living in neighbouring. N. S. W. towns, where the community water supplies consisted of artesian and river were respectively. The demographic characteristics, living pattern and dietary carbohydrate challenge were similar in the two areas and effective oral hygiene practices were uniformly lacking. Children in the artesian water area had 40% lower caries prevalence (DIMFT), 50% less severe carious lesions (SR) and significantly better oral hygiene (OHI) and gingival condition (PI) and correspondingly lesser treatment needs than those supplied by river water. The findings were examined in relation to the concentrations of 10 elements in roof catchment, river and artesian water. Apart from a contribution by fluoride to better oral health, the results implicate lithium as a possible beneficial element.

Australia↗
PubMed1981

Stylohamular dissection: a new method for en bloc reaction of malignancies of the infratemporal fossa.

This study is a description of the "stylohamular" dissection, a technique for the en bloc resection of the infratemporal fossa. The medial plane of this dissection extends from the styloid process to the hamulus of the pterygoid just lateral to the foramen lacerum, allowing the surgeon to spare the internal carotid artery. The foramen ovale and foramen spinosum are routinely exposed during this procedure. Medially, the pterygoid musculature serves as the margin of the cancer block. Posteriorly, the mastoid tip may be included in this resection. Anteriorly, the lateral pterygoid plate is resected making it the anterior vertical plane of the dissection. Laterally, skin and mandible are the block margins. In the last three years, this approach has been utilized in eight patients with advance malignancies involving the infratemporal fossa. The results are encouraging. Five patients have remained well and free of disease for a maximum of three years postoperatively. Two patients have had recurrence of their tumor from six months to one year postoperatively. Palliation in all patients was excellent. The literature on various infratemporal dissections and their results is reviewed.

Adult↗
PubMed1980

Oral conditions in Australian children of Aboriginal and Caucasian descent.

Oral health parameters were examined for 211 schoolchildren (128 Aborigines and 83 Caucasians) representative of the 6--8 and 10--11 year age groups in the Brewarrina and Walgett areas of western New South Wales (fluoride in water less than or equal to 0.02-0.26 parts/10(6)). Despite similar dietary carbohydrate challenge and tooth eruption patterns, Aboriginal children, most of whom were members of a transitional community within a low socioeconomic stratum, had higher prevalence of caries (DIMFT) and severity rating of carious lesions (SR), poorer oral hygiene (OHI) and more gingivitis (PI) than Caucasian children, in both age groups. Tooth defects were more frequent (2.5 times) and severe in Aborigines than in Caucasians. Outstanding treatment needs were very high in both ethnic groups, but more so in Aborigines.

Australia↗
PubMed1980

Oral health of adolescent and adult Australian aborigines.

A pilot survey of oral health included 83 adolescent and adult Aborigines (41 M, 42 F, range 16--70 years, mean age 37.3 years), resident in fringe settlements around the far western New South Wales towns of Brewarrina and Walgett (fluoride in water less than or equal to 0.02--0.26 parts/10(6)). Dental caries prevalence (mean DIMFT per person) increased from 17.1 at 20 years to 10.7 at 35 years and declined to 14.6 by the age of 50 years and over. Oral hygiene (OHI) was poor overall and deteriorated with age. Periodontal status (PI) was significantly correlated with the presence of debris (DI) and calculus (CI). The mean PI increased from 1.7 at 20 years to 4.8 at 43 years and over. Tooth mortality reached 75% by the age of 43 years. Prosthetic needs were correspondingly high, but 95% of denture requirements were unmet. No evidence of effective or sustained oral health care was seen; 38% of subjects needed emergency treatment.

Adolescent↗
PubMed1978

The neurons and the synaptic endings in the primate basilar pontine gray.

Two types of neurons, projection and intrinsic, previously identified in Golgi preparations of the adult monkey (Macaca mulatta) basilar pontine gray (Cooper and Fox, '76) were observed electronmicroscopically in Macaca mulatta and the squirrel monkey Saimiri sciureus. The cell body of the projection neuron measures up to 37 micrometer and its cytoplasm is rich in organelles. The Goli apparatus, ribosomes, and mitochondria are disposed around the nucleus, while rough endoplasmic reticulum though abundant is usually confined to one half of the cell body. The cell body of the intrinsic neuron measures less than 20 micrometer and its cytoplasm displays prominent ribosomes, but a paucity of other organelles. Five types of synaptic profiles have been identified in the neuropil of the basilar pons; one measures up to 5 micrometer and the rest 2 micrometer or less. They are: (1) a large profile (MSV) containing medium size vesicles (500A) and a central core of mitochondria and neurofilaments; (2) a profile (SSV) containing small round vesicles (250-500 A) which is the most abundant and ubiquitous; (3) a profile (F) containing flattened or pleomorphic vesicles; (4) a profile (LSV) containing large oval egg shaped vesicles (750 A); and (5) a pale profile (PP) that contains oval and occasionally pleomorphic vesicles. MSV, SSV, and LSV terminals form asymmetrical contacts and F terminals form symmetrical contacts with both dendritic and vesicle-containing, pale profiles. The vesicle-containing, pale profile is both pre- and post-synaptic and participates in serial synapses. Following unilateral cortical ablations both dark and filamentous degeneration were observed in the ipsilateral basilar pontine gray.

Animals↗
PubMed1977

Neuronal cytoplasmic inclusions in the dorsal horn and supraoptic nucleus of the squirrel monkey, Saimiri sciureus.

In the squirrel monkey (Saimiri sciureus) two types of cytoplasmic inclusion bodies have been observed sporadically in neurons of both the dorsal horn (Rexed's laminae I-III in the lumbosacral region) and the supraoptic nucleus. One of these, designated here the "vesicular body", is a round inclusion which measures up to 1.4 mu in diameter. It occurs only in perikarya and is composed of vesicular-like chambers 300-400 A in diameter. We have not found previous references to this structure in the literature, but its 50 A substructural particles are similar in size to those described in nematosomes. The other inclusion, a "filamentous whorl", is found in nerve cell bodies and dendrites and it is structurally similar to the Hirano body. The structure measures up to 2.2 mu in diameter and is composed of circularly arrayed filaments which vary in configuration and size depending on the plane of section. There are no indications that the vesicular body and the filamentous whorl are in any way related to each other; and usually both are not found in the same cell profiles.

Animals↗
PubMed1977

Myelinated granule cell bodies in the cerebellum of the monkey (Saimiri sciureus).

Electronmicrographs of both the vermis and hemisphere of the cerebellum of the squirrel monkey (Saimiri sciureus) show numerous granule cell bodies partially or completely surrounded by myelin. The myelin is of the compact type and consists of 1 to 13 lamellae. In several cases of partially ensheathed cells the myelin is clearly derived from extensions of myelin sheaths that surround small caliber axons. Either all or only the outer lamellae surrounding the axon contribute to the extensions. In the first instance the myelin buckles at its mesaxon pole and the resulting doubled flap extends for a variable distance along the cell surface.

Animals↗
PubMed1977

Timing control accuracy in normal speakers and stutterers.

This study attempted to assess the abilities of 10 normal speakers, five stutterers in therapy, and five stutterers no longer in therapy, to control the time program of repeated utterances. The speech sample comprised repeated sentences, paragraphs, and nursery rhymes, and a finger-tapping task was included as a control. Temporal accuracy was measured. Results suggest that (1) there is a wide range of timing abilities, even among the normal speakers, with considerable overlap between the different groups of speakers; (2) on most of the experimental tasks, normal speakers are more accurate timers than are stutterers; (3) stutterers released from therapy are more accurate timers than are stutterers still in therapy, whenever these groups differ; and (4) subjects' speech timing scores correlate moderately with their tapping scores. These results are discussed in terms of (1) theoretical timing control processes, such as a neural clock for controlling speech segment durations, and a speech motor output buffer, whose capacity may be limited in stutterers, and (2) known effects of rhythmic constraints and respiratory irregularity on fluency.

Female↗
PubMed1976

Myelinated nerve cell bodies in the dorsal horn of the monkey (Saimiri sciureus).

While observing electronmicroscopic preparations of laminae I-III of Rexed ('52), taken from the lumbosacral region of squirrel monkey spinal cord, several small neuronal cell bodies were found which were partially or completely encircled by compact myelin sheaths of varying thickness. Though found in all three laminae, the occurrence of these perikaryal sheaths was less frequent in the "inner zone" of lamina II where there were few myelinated fibers. Perikaryal profiles which were completely surrounded by myelin exhibited meither internal mesaxons nor external tongue processes and the origin of their myelin is obscure. In cases of partially enveloped cells the myelin was often clearly derived from extensions of myelin sheaths surrounding small-diameter axons. These overgrowths of myelin extended away from their axons at a pole near their internal mesaxon and spread out across the surface of neighboring nerve cells. In some cases the extensions were derived from the entire axonal sheath while in others only the external lamellae were included. The external tongue process, when observed, was located at the distal end of the axonal myelin extension. Overgrowths of axonal myelin which were unrelated to neuronal cell bodies were also found but these formations were less extensive.

Animals↗