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Biomedical subjects

P C Reade

Publications and source records attributed to P C Reade.

At least 145 records · Page 8Linked to original sources

The histopathologic features which follow repeated applications of tobacco tar to rat lip mucosa.

The response of rat lip mucosa to two tobacco tar preparations combined with heat was examined histopathologically. It was shown that the magnitude of irritational hyperplasia produced was related to the level of irritation. This was greatest in those rats subjected to the longest period of application of the tobacco extract with the greatest concentration of tar combined with heating the site of application. Neoplastic changes were not produced.

Animals↗

Residual complications in patients with major middle third facial fractures.

Residual complications associated with middle third facial fractures have been poorly documented in the literature. In the present study, 240 patients with fractures of the middle third of the facial skeleton, who were treated at the Royal Melbourne Hospital, Victoria, between 1969 and 1976, were reviewed to determine the residual complications of these fractures. Cranial complications were relatively uncommon, and 60 % of cases of cerebrospinal fluid rhinorrhoea ceased within 3 days of fracture reduction and fixation. Persistent infraorbital sensory defects occurred in 22 % of patients with Le Fort II or Le Fort III fractures. Orbital complications included diplopia, which remained in 8 % of cases, and was often corrected by secondary surgery. Residual complications involving the nose or maxillary sinus were uncommon (less than 5 %). Occlusal disharmony was present as a residual problem in 19.6 % of cases, although this could be managed by simple means in 89 % of these cases so that primary surgery and simple secondary dental procedures a satisfactory result in 98 % of all patients. The low incidence of dental complications is most likely a result of the rigid fixation employed in the fracture management, allowing accurate control of the bone fragments.

Brain Diseases↗

Incidence and management of major middle third facial fractures at the Royal Melbourne Hospital. A retrospective study.

In a retrospective study of 240 patients with major fractures of the middle third of the facial skeleton, the incidence, anatomical patterns, and management of these fractures have been reviewed, and an assessment made of the concomitant injuries to other organs. Most of the fractures occurred in the 20-29-year age group (39%), and over 83% of the patients in this study were males. The most common cause of injury was road accidents (80.8% of all cases), and automobile occupants represented most of this group. The Le Fort II fracture was the most commonly sustained, and there were several variations from the classical fracture patterns recorded, combinations of fractures at different levels being frequent. Ninety percent of patients had another concomitant injury, indicating the need for multi-disciplinary care of this type of patient. The most common treatment method involved the use of craniomaxillary and intermaxillary fixation, which was usually maintained for 22-28 days.

Accidents, Occupational↗

An immunohistochemical study of secretagogue-induced secretion of epidermal growth factor in the submandibular salivary glands of mice.

Routine histological and indirect immunofluorescence techniques were used to examine the histological details of changes in the distribution of epidermal growth factor (EGF) in the submandibular salivary glands of mice during secretion. Comparisons were made bewteen glands of normal mice and those of mice given one of a number of secretagogues at various times prior to sampling. Normal submandibular salivary glands in male mice had an extensive system of convoluted granular tubules (CGT), the cells of which contained EGF. When adrenaline of alpha-phenylephrine was administered, the CGT cells degranulated, and there was a concomitant loss of intracellular EGF-positive immunofluorescence. The excretory ducts were engorged with immunofluorescent material, indicating secretion of EGF into saliva, while the ductal cells themselves remained EGF-negative. The degranulation response could be blocked by phentolamine, but not by propranolol, and no changes in EGF distribution followed the administration of pilocarpine. It was concluded that EGF is secreted, at least partly into the saliva, following an alpha-adrenergic response, and that this occurs with degranulation of the cells of the CGT.

Animals↗

Xenografts of recombined bovine odontogenic tissues and cultured cells to hypothymic mice.

It was demonstrated in this study that recombined tissues of bovine dental papilla and reduced enamel epithelium, when transplanted to the subcapsular kidney site of hypothymic mice, elaborated tissues resembling osteodentin and dentin matrices with which latter tissues were closely associated cells resembling odontoblasts. In xenografts of cultured cell populations of these tissues, osteodentin-like matrices occurred in the absence of dentin-like matrices.

Animals↗

The distribution of [14C] leucine and 85Sr labeled microspheres from rat incisor root canals.

The distribution of [14C] leucine and 85Sr labeled tracer microspheres from rat incisor pulp canals was investigated in an effort to establish the potential for passage of substances from within the root canal to the systemic circulation. Following introduction of the tracer materials into the pulp canals, the radioactivity in the lungs, spleen, kidney, liver, heart, blood, skeletal muscle, adrenal glands, salivary glands, and submandibular lymph nodes was determined. At all of the time intervals studied the incorporation of [14C] leucine into the adrenal gland was significantly greater than the [14C] leucine incorporation into the other organs. High levels of 85Sr labeled microspheres were detected in the ipsilateral submandibular glands and submandibular lymph nodes and in the lungs.

Animals↗

Arteriovenous shunts demonstrated in the apical circulation of rat incisor teeth by the use of radio-labeled microspheres.

The distribution of systemically introduced 85Sr-labeled tracer microspheres to unexposed and previously exposed rat lower incisor tooth pulps was investigated. Fewer tracer microspheres entered the microcirculation of pulps that had been previously exposed as compared to control unexposed pulps. The presence of large numbers of dilated blood vessels in the apical tissues of teeth with exposed pulps was observed, and it is postulated that these vessels may be operating as arteriovenous anastomoses so that the pulpal microcirculation of teeth with inflamed pulps is bypassed by the tracer microspheres. The possible clinical significance of these findings is discussed.

Animals↗

Tobacco smoking habits and attitudes of Australians with oral mucous membrane keratoses.

The purpose of this study was to ascertain whether or not a relationship existed between the presence of oral mucous membrane keratoses and tobacco smoking habits. Two groups of tobacco smokers, one group exhibiting oral mucous membrane keratoses, and the other no such changes, were chosen for their similar smoking habits. Detailed tobacco smoking histories of each group were ascertained. Similar results for both groups, in terms of the number of years of smoking, quantity of tobacco consumed dialy, type of tobacco smoked and the method of inhalation and exhalation were found. Eighty per cent of patients wanted to stop smoking with the fear of cancer being the major reason in the subjects with oral keratoses and the continued cost of smoking the major reason in the control subjects. In the affected patients the prevalence of white patches was not related to the quantity of tobacco consumed but rather to the number of years the subject had smoked.

Attitude↗

D-penicillamine-induced mucocutaneous lesions with features of pemphigus.

Penicillamine (beta1 beta2 dimethylcysteine) is the drug of choice in the therapeutic management of Wilson's disease and cystinuria and has been used in the treatment of some heavy-metal intoxications. Recent studies have shown that it is efficacious in patients with rheumatoid arthritis. Side effects include sensitivity reactions, nephrotoxicity, bone-marrow suppression, hypogeusia, skin lesions, and the formation of autoantibodies. Two cases are described with the features of pemphigus which were attributed to penicillamine therapy.

Aged↗

Protein and DNA levels in the submandibular salivary glands of isoproterenol stimulated mice.

The DNA and soluble and sedimental protein levels were studied in isoproterenol stimulated mouse submandibular salivary glands over a period of 200 h. Hypertrophy, the predominant cellular phenomenon following chronic isoproterenol treatment, was associated with a marked elevation of 14C-leucine incorporation into the buffer soluble protein fraction and a less pronounced isotope incorporation into the sedimental sub-cellular fraction as well as continued DNA synthesis. These findings are contrary to the accepted definitions of hypertrophy which preclude continued DNA synthesis. A suggestion is made, therefore, that in the system used the polyploidy associated with the hypertrophy involves.

Animals↗