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Biomedical subjects

P C Reade

Publications and source records attributed to P C Reade.

At least 37 records · Page 2Linked to original sources
PubMed1996

Induction by 4-nitroquinoline-1-oxide of oral epithelial dysplasia and neoplasia in scurvy-prone osteogenic disorder Shionogi (ODS) rats.

Carcinogenesis by 4-nitroquinoline-1-oxide (NQO) in the oral mucosa is a reliable method of obtaining oral mucosal squamous cell carcinoma (OMSCC) and allows examination of various stages of oral cancer development. In vivo and in vitro studies have indicated that L-ascorbic acid (AA) may have a role in cancer prevention. The Wistar "scurvy-prone" osteogenic disorder Shionogi (ODS) rat of the od/od substrain is unable to synthesize AA and requires supplementation for its survival. This study examined the effects of NQO on the oral mucosa of ODS and outbred Wistar rats. NQO (0.5%) was applied topically to the palatal mucosa of 72 male ODS and 36 outbred Wistar rats three times weekly for 4, 8, 12, 16, 20, and 24 wks. The ODS rats were divided so that 36 rats were given 2.5 g/l AA in the drinking water and 36 rats were given 0.33 g/l AA. Vehicle-treated and untreated control animals were included. The rats were killed two weeks after the final NQO application, and the tissues were examined. Epithelial dysplasia was assessed using a modified Smith and Pindborg (1969) index. The ordered categorical scores were analyzed appropriately. Plasma AA levels were checked in ODS and outbred rats at the start and end of the experiment. The results indicated that the oral mucosa of the ODS and outbred rats were susceptible to NQO but that the rate of dysplasia and OMSCC development differed between them, with more rapid changes being found in the ODS rats (p < or = 0.05). No significant difference was found in the dysplasia scores and in the rate of OMSCC development between ODS rats given 2.5 g/l of AA and ODS rats given 0.33 g/l of AA (p > 0.05). No epithelial changes were observed in the palatal mucosa of vehicle-treated and untreated controls. The plasma AA level mean (+/- SEM) was 56 +/- 6 microM for the outbred rats, 8 +/- 1 microM for the ODS rats given 0.33 g/l AA supplementation, and 29 +/- 2 microM for the ODS rats given 2.5 g/l AA. It was concluded that the chronic AA-deficient state in ODS rats played an insignificant role in oral carcinogenesis and that other factors, for example, genetic differences in susceptibility to NQO, contributed to the present findings.

4-Nitroquinoline-1-oxide↗
PubMed1996

Expression of c-erbB-2 protein in keratinocytes of oral mucosal lichen planus and subsequent squamous cell carcinoma.

Oral mucosal lichen planus (OMLP) is a well recognized mucosal disease with unknown etiology. Considerable controversy exists as to whether OMLP is intrinsically premalignant, or if the disorder facilitates the development of oral mucosal squamous cell carcinoma (OMSCC) by external factors. The aim of the present study was to investigate the expression of c-erbB-2 protein in the keratinocytes of initial biopsies or oral mucosal disorders diagnosed as OMLP with no evidence of epithelial dysplasia, and to compare the results with the expression of c-erbB-2 protein in subsequent biopsies obtained from the same patients. These results were compared with the findings from control groups (patients with dysplasia with no evidence of OMLP, patients with OMSCC with no evidence of OMLP and normal oral mucosa). The expression of the c-erbB-2 protein was evaluated by immunohistochemical staining of the gene product with the avidin-biotin-complex method using paraffin-embedded tissues sections. Five of the initial biopsies from patients with OMLP expressed the c-erbB-2 protein and one did not. None of the OMLP cases that subsequently showed evidence of dysplasia expressed the c-erbB-2 protein, and of the three OMSCC specimens from the patients with OMLP, two were negative and one expressed c-erbB-2 protein. The specimens from the control groups all expressed the c-erbB-2 protein. The results indicated the probability of the absence of c-erbB-2 staining being an indication of a potential for neoplastic transformation in OMLP with dysplastic changes.

Adult↗
PubMed1996

The prognosis of oral mucosal squamous cell carcinomas: a comparison of clinical and histopathological grading and of laminin and type IV collagen staining.

Changes in the distribution of basement membrane components have been described in dysplastic lesions and in oral mucosal squamous cell carcinomas (OMSCC). The purpose of this study was to determine if these changes were related to pathological grade and if so, whether this had prognostic implications. Fifty formalin-fixed, paraffin-embedded specimens of OMSCC, with five or more years clinical follow-up, were studied using an immunoperoxidase technique for the detection of the basement membrane components, laminin and type IV collagen. The immunoreactivity of each component was evaluated and semiquantitatively scored as minimal, moderate or extensive and the results compared with the tumour size, node involvement and metastasis (TNM) clinical staging system and histopathological features. OMSCC were characterized by minimal or moderate staining with small islands of neoplastic cells frequently lacking staining for laminin and type IV collagen. Deposition of these components decreased with increased histopathological grade and absence of staining was more commonly associated with a poor prognosis. In particular the pattern of type IV collagen staining frequently differed from laminin staining. Neither of these parameters offered an advantage over TNM clinical staging with regard to prognosis. It was concluded that variations in laminin and type IV collagen immunoreactivity occurred in OMSCC and that high histopathological grade tumours with considerably diminished staining with anti-laminin and anti-type IV collagen carried a poor prognosis.

Basement Membrane↗
PubMed1996

Studies of the inflammatory process and malignant potential of oral mucosal lichen planus.

Oral mucosal lichen planus (OMLP) is a well recognized mucosal disease with unknown aetiology. Considerable controversy exists as to whether OMLP is intrinsically premalignant, or if the disorder facilitates the development of oral mucosal squamous cell carcinoma (OMSCC) by external factors. The aim of the present studies was to investigate the expression of c-erbB-2 protein in the keratinocytes of the initial biopsies of oral mucosal disorders diagnosed as OMLP with no evidence of epithelial dysplasia and to compare the results with the expression of c-erbB-2 protein in subsequent biopsies obtained from the same patients. These results were compared with the findings from another 26 biopsies from patients with OMLP and control groups (patients with dysplasia with no evidence of OMLP, patients with OMSCC with no evidence of OMLP and normal oral mucosa). The expression of the c-erbB-2 protein was evaluated by immunohistochemical staining of the gene product with the avidin-biotin-complex method using both fresh frozen and paraffin-embedded tissue sections. Five of the initial biopsies from patients with OMLP expressed the c-erbB-2 protein and one did not. None of the OMLP cases that subsequently showed evidence of dysplasia expressed the c-erbB-2 protein and of the OMSCC specimens from the patients with OMLP, 2 were negative and 1 expressed c-erbB-2 protein. Within the other group of OMLP specimens 3 (3/26) were negative for c-erbB-2 staining. The specimens from the control groups all expressed the c-erbB-2 protein. The results indicated the probability of the absence of c-erbB-2 staining being an indication of a potential for neoplastic transformation in OMLP with dysplastic changes.

Carcinoma, Squamous Cell↗
PubMed1996

Determination of the L-ascorbic acid requirements in Wistar osteogenic disorder Shionogi rats for prolonged carcinogenesis experiments.

Wistar Shionogi rats of the (od/od) substrain with the osteogenic disorder are unable to synthesize L-ascorbic acid (L-AA) and appear to be an appropriate animal model for studying the effect of L-AA in carcinogenesis. To determine the minimal L-AA requirements of these animals for prolonged survival in a satisfactory physical condition during experimentation, four concentrations of L-AA (0.33 g/l, 0.67 g/l, 1.67 g/l and 3.33 g/l) were administered via drinking water to four groups of animals (n = 2). Their water intake per cage was recorded three times weekly and the plasma L-AA levels were determined at the start, after 2, 4, 8 and 12 weeks and at the termination of the experiment. To simulate the procedures to be undertaken in oral mucosal carcinogenesis experiments, the animals were gently restrained and a designated amount of sterile NaCl was applied to the palatal mucosa three times a week for 26 weeks. The L-AA supplement group with the lowest concentration (0.33 g/l L-AA) achieved mean plasma levels of 7 +/- 1.38 microM, approximately one-eighth that of the normal level (mean plasma L-AA level in outbred Wistar rats was found to be 58 +/- 3 microM) whilst those in the higher supplement group (3.33 g/l L-AA) achieved a mean of 18 +/- 1.25 microM. All of the animals employed in the present study survived for 26 weeks and showed no clinical signs of L-AA deficiency during this period.

Animals↗
PubMed1995

A comparison of the effects of group function and canine guidance interocclusal device on masseter muscle electromyographic activity in normal subjects.

This study investigated the role of occlusal balance and canine guidance or group function guidance in masseter muscle function of normal subjects. Two types of interocclusal devices were constructed for each of the 10 subjects. Two ME 1020 EMG analyzers and bipolar Ag/AgCI electrodes were used to record the electromyographic activity of masseter muscles during clenching in centric occlusion, during left and right laterotrusive movements, and during clenching at the extremities of the jaw both with the natural dentition only and with adjusted and intentionally unadjusted interocclusal devices in place. This study demonstrated that there was no difference in masseter muscle electromyographic activity between the use of interocclusal devices designed for canine guidance or for group function guidance in normal subjects. It showed also that altering the occlusal balance significantly reduced muscle activity.

Adult↗
PubMed1995

The expression of c-erbB-2 protein in the keratinocytes of oral mucosal lichen planus.

The expression of the c-erbB-2 protein was studied in the keratinocytes from patients with: (i) oral mucosal lichen planus (OLP) (n = 26); (ii) oral mucosal squamous cell carcinoma (OMSCC) which had arisen in mucosa affected by OLP (n = 5); and (iii) normal oral mucosa (n = 5). C-erbB-2 protein was expressed on the cell membranes of the keratinocytes of nucleated epithelium in the stratum spinosum. The antigenic determinant recognized represents the cytoplasmic domain of a cell surface receptor which binds an as yet uncharacterized heparin binding ligand of unknown function. The specimens from the five normal subjects showed positive immunohistochemical staining with the monoclonal c-erbB-2 protein antibody, the OMSCC specimens were negative, and 23 of 26 of the OLP specimens were positive. The lack of c-erbB-2 expression in the three OLP and in the five OMSCC specimens may indicate a genetic alteration, or masking of the expression of c-erbB-2. The absence of expression in OLP specimens might be an indicator of the possibility of future neoplastic transformation.

Carcinoma, Squamous Cell↗
PubMed1995

Oral Candida albicans from patients infected with the human immunodeficiency virus and characterization of a genetically distinct subgroup of Candida albicans.

Candida albicans has been shown to vary in its phenotypic expression with the progression of human immunodeficiency virus (HIV) infection. This study was designed to investigate whether in Category IV HIV infected patients (CDC, Atlanta, USA) these phenotypic changes were related to changes in the genetic strain of the organism. Isolates of C. albicans were obtained from 45 patients with HIV infection during the progression of their disease as determined by percentage T4 lymphocyte count. Isolates were strain differentiated using two methods. In 67 per cent of the patients a single strain of C. albicans, as determined by the DNA analysis, was isolated from each individual over the experimental period. The phenotypic expression of the genetically identical strains isolated from each patient varied considerably over the experimental period with the morphotype 754 being predominant. These results showed that the genotype of C. albicans isolated persisted in the majority of HIV infected individuals, but that the phenotypical expression of this strain changed. A finding in this study was that 18 strains of C. albicans had DNA which did not hybridize to the probe used. These strains were analysed for the presence of two other C. albicans specific DNA segments using PCR. The probe 27A hybridizing strains yielded PCR products which differed from the non-hybridizing strains. Five of these genetically atypical C. albicans strains and 98 of the C. albicans strains were then analysed for purported virulence factors.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Opportunistic Infections↗
PubMed1995

Temporomandibular disorders: a critical review of the nature of pain and its assessment.

Temporomandibular disorders is a common form of chronic pain affecting the head, face, and jaw. The distinguishing symptoms of this disorder include pain and impairment of the masticatory function, and frequent display of symptoms, ranging from aches in the head, neck, ears, and eyes, to atypical toothaches, throat symptoms, and occlusal changes. It is recognized that pain is a complex, multifactorial experience including not only sensory dimensions, but also affective and cognitive factors. Recent recommendations regard temporomandibular disorders as a dual-axis disorder with physical and psychologic dimensions, but little research has incorporated measures of multidimensional pain characteristics in the assessment of temporomandibular disorders. This article is a review of the literature on the psychophysiologic factors contributing to temporomandibular disorders and its limitations. Recommendations for future research are also given.

Afferent Pathways↗
PubMed1994

Temporomandibular pain dysfunction disorder resulting from road traffic accidents--an Australian study.

The relationship between temporomandibular pain dysfunction disorder (TMPD) and trauma to the head and neck is unclear. A retrospective analysis of the records from the Transport Accident Commission (TAC) of Victoria, Australia, in the year 1987, was done to identify those subjects who received treatment for TMPD resulting from a road traffic accident (RTA). Twenty-eight subjects with TMPD were identified from a total of 20 673 subjects who claimed health care services from the TAC for RTA-related disorders. In this study, TMPD for which subjects sought treatment was uncommonly associated with either direct or indirect trauma to the temporomandibular joints: 0.4% of subjects with mandibular fractures and 0.5% of subjects with whiplash injuries presented for treatment of an associated TMPD. Females were found to present for treatment of TMPD more commonly than males at a ratio of 5:2. It was also noted that 75% of subjects complained of symptoms of TMPD immediately after the accident and approximately 96% within 2 months of the accident. Subjects were not lost to follow-up because all claims for treatment were made to the TAC, regardless of the clinician involved. In this study, 25% of subjects attended more than one dentist for management. It was concluded that TMPD for which subjects sought treatment was an uncommon result of an RTA and was infrequently associated with a mandibular fracture or whiplash injury.

Accidents, Traffic↗
PubMed1994

Genotype and phenotype of oral Candida albicans from patients infected with the human immunodeficiency virus.

Candida albicans has been shown to vary in its phenotypic expression with the progression of human immunodeficiency virus (HIV) infection. Isolates of C. albicans were obtained from 45 patients with HIV infection during the progression of their disease and differentiated using two methods. The first utilized the morphological characteristics of colonies, and the second method utilized a small portion of C. albicans DNA as a probe on Southern-transferred, EcoRI-digested C. albicans genomic DNA. In 67% of the patients a single strain of C. albicans, as determined by the DNA analysis, was isolated from each individual. The phenotypic expression of the genetically identical strains varied considerably over the experimental period with one morphotype being predominant. These results showed that the genotype of C. albicans persisted in the majority of HIV-infected individuals, but that the phenotypical expression of this strain changed. A novel finding in this study was that 18 strains of C. albicans had DNA which did not hybridize to the probe used.

Candida albicans↗
PubMed1994

Oral mucosal ulceration due to cytomegalovirus associated with human immunodeficiency virus infection. Case report and brief review.

Reports of oral lesions associated with cytomegalovirus (CMV) infection in human immunodeficiency virus (HIV) infected patients are uncommon. In this article a case of CMV infection associated with oral mucosal ulceration and a brief review of the subject is presented. Establishing the cause of ulceration is important in determining a definitive diagnosis and prescribing appropriate therapy. It is important to recognize that CMV associated oral mucosal ulceration may be the initial manifestation of human immunodeficiency virus (HIV) infection.

AIDS-Related Opportunistic Infections↗
PubMed1993

Role of thermal trauma in experimental oral mucosal Candida infections in rats.

A model of candidosis in experimental rats was used to study the role of trauma in the aetiology of oral mucosal infections caused by Candida albicans. Standardised thermal trauma was delivered to the dorsum of the tongue of Sprague-Dawley rats and experimental candidosis was induced. Histologically, the site of trauma was invaded by hyphae earlier and more extensively than in control animals, leading to the conclusion that trauma facilitated the establishment of the C. albicans infections.

Animals↗
PubMed1992

Candida species and Candida albicans morphotypes in erythematous candidiasis.

A group of full-denture-wearing patients with erythematous candidiasis was matched by age and sex with a group of healthy, full-denture-wearing persons who served as controls. In the group with erythematous candidiasis, clinical symptoms and signs of the disease were recorded. Denture hygiene and tobacco use were noted in both groups. Epithelial smears and imprint cultures were obtained from both groups from specified sites. Cultures were grown and subjected to species identification and C. albicans strain differentiation by a morphotyping technique. Denture-wearing subjects who smoked tobacco had a significantly greater incidence of erythematous candidiasis than the controls. Five species of Candida were isolated from both groups, with C. albicans as the dominant species. Twenty different morphotypes of C. albicans as well as strains involved in erythematous candidiasis were also isolated from the oral cavities of healthy, full-denture-wearing control subjects.

Aged↗
PubMed1992

Multiple endocrine neoplasia syndrome--type 2b. Case report and review.

The multiple endocrine neoplasia syndromes are an association of tumours of 2 or more endocrine glands. Multiple endocrine neoplasia type 2b (MEN 2b) patients develop medullary thyroid carcinoma and pheochromocytomas as well as unique physical characteristics. Most commonly, MEN2b is inherited with an autosomal dominant pattern although sporadic cases are not uncommon. If untreated the disease may be lethal. The facial, oral and ocular characteristics are reliable markers of the disease. These patients give a history most commonly of slipped capital femoral epiphysis, hypertension and life-long diarrhoea and/or constipation. MEN2b is most commonly characterised by nodules on the anterior aspect of the tongue, thickened lips with nodules, thickened upper eyelids, broadened nasal bridge, thickened corneal nerves and dilated, symmetrical, pedunculated nodules on the cheek mucosa. The patient described has most of these characteristics. Radiographic features of the jaws which have not been previously described are reported. These include a markedly enlarged and bifurcated inferior alveolar canal and shortened roots of the lower incisor teeth. Due to the lethality of the disease, patients who present with the above physical characteristics must be further investigated to exclude MEN2b.

Adrenal Gland Neoplasms↗
PubMed1992

Candida albicans as a promoter of oral mucosal neoplasia.

A model of oral mucosal carcinogenesis using the water-soluble carcinogen 4-nitroquinoline-1-oxide (4NQO) was combined with a model of oral mucosal candidosis to examine the ability of Candida albicans to promote the development of neoplasia in suitably initiated epithelium. Sprague-Dawley rats were initiated by the application of 4NQO to their palatal and tongue mucosa 3 times weekly for 4 weeks. The animals then received either application of a phorbol ester to act as a promoter, induction of experimental oral mucosal infection with C. albicans, or no further procedures. Animals were killed at 34 or 52 weeks and the tongues and palates sectioned for light-microscopic examination. Control groups with no treatment, mucosal infection only, phorbol ester application only, 4NQO with the tetracycline or vehicle application only were also used. The development of carcinoma in the experimental groups was similar to that in the positive control groups, indicating that the particular strain of Candida used had a similar ability to promote neoplastic changes as the known promoter phorbol-12,13-didecanoate and caused neoplastic changes to occur by week 34 with no additional lesions occurring by week 52. This indicated that the speculation that strains of C. albicans may participate in causing neoplastic transformation in humans was well founded.

4-Nitroquinoline-1-oxide↗
PubMed1992

Direct immunofluorescence of oral mucosal biopsies: a comparison of fresh-frozen tissue and formalin-fixed, paraffin-embedded tissue.

The diagnosis of some oral mucosal diseases can be facilitated by the use of direct immunofluorescence. Fresh frozen tissue is preferred when using this technique, however frequently the material received by the histopathology laboratory has been fixed in formalin. Enzyme digestion of tissue sections glued to glass slides prior to incubation with antibodies was shown in this study to give comparable results with direct immunofluorescence on fresh frozen tissue and can be used for diagnostic purposes when fresh frozen tissue is unavailable or not representative of the disease process.

Basement Membrane↗