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Biomedical subjects

S R Porter

Publications and source records attributed to S R Porter.

At least 109 records · Page 6Linked to original sources
PubMed1997

Immunologic aspects of dermal and oral lichen planus: a review.

There have been many investigations, both experimental and epidemiologic, of the forms of LP affecting the skin and oral mucosae. These studies have provided a varied range of hypotheses to explain not only the factors determining susceptibility to and onset of this disease, but also the immunologic mechanisms leading to the pathosis with which LP is associated. Much progress has been made, especially through in vitro studies, regarding detailed aspects of the immunology of LP. However, data is often conflicting or incomplete. In this review we attempt to bring together the currently available data regarding the immunologic basis of LP.

Animals↗
PubMed1997

The clinical spectrum of desquamative gingivitis.

Desquamative gingivitis is a fairly common complaint. Typically seen in females who are middle-aged or older, it is predominantly a manifestation of a range of vesiculobullous disorders. The main complaint is of persistent soreness of the gingiva. Most cases are related to lichen planus or pemphigoid, but it is also important to exclude pemphigus, dermatitis herpetiformis, linear IgA disease, chronic ulcerative stomatitis, and other conditions. Biopsy is invariably required to confirm the diagnosis after a full history, general, and oral examination. Apart from improving the oral hygiene, immunosuppressive therapy is typically required to control the condition.

Adult↗
PubMed1997

Local antimicrobial therapy of oral mucositis in paediatric patients undergoing bone marrow transplantation.

The present investigation has examined the clinical benefits of tobramycin, polymyxin E and amphotericin therapy in the management of oral mucositis in children undergoing chemotherapy prior to bone marrow transplantation. Tobramycin, polymyxin E, and amphotericin reduced the degree of oral mucositis more than conventional therapy of diphenhydramine, Maalox, and local analgesic. While there was a statistically significant fall in the severity of the mucositis with tobramycin, polymyxin E and amphotericin, this was unlikely to be of practical benefit.

Adolescent↗
PubMed1997

Oral hairy leukoplakia: clinicopathologic features, pathogenesis, diagnosis, and clinical significance.

Oral hairy leukoplakia (OHL) is a lesion frequently, although not exclusively, observed in patients infected by human immunodeficiency viruses (HIV). OHL is clinically characterized by bilateral, often elevated, white patches of the lateral borders and dorsum of the tongue. Histologically, there is profound acanthosis, sometimes with koilocytic changes, and a lack of a notable inflammatory infiltrate. The koilocytic changes are due to intense replication of Epstein-Barr virus (EBV), while epithelial hyperplasia and acanthosis are likely to result from the combined action of the EBV-encoded proteins, latent membrane protein-1, and antiapoptotic BHRF1. How OHL is initiated and whether it develops after EBV reactivation from latency or superinfection remain unresolved; nevertheless, definitive diagnosis requires the demonstration of EBV replicating vegetatively in histological or cytological specimens. In patients with HIV infection, the development of OHL may herald severe HIV disease and the rapid onset of AIDS, but despite its title, OHL is not regarded as premalignant and is unlikely to give rise to oral squamous cell carcinoma.

HIV↗
PubMed1997

Presence of human herpesvirus 8 variants in the oral tissues of human immunodeficiency virus-infected persons.

A 210-bp DNA segment specific to the human herpesvirus 8 (HHV-8) genome was amplified by nested polymerase chain reaction from 10 of 14 archived oral biopsy samples of HIV-positive patients in London who had no evidence of oral Kaposi's sarcoma (KS). Various oral sites were represented. Oral tissues from 20 general dental patients not known to be HIV-infected were negative. When DNA sequences of these products were compared with sequences derived from 5 oral KS tissues of AIDS patients in London and 10 skin biopsies of Italian patients with Mediterranean KS (total number of positive tissues = 25), 11 were found to be unique. DNA and predicted peptide motifs of these sequences were also different from those in 28 of 36 HHV-8-positive lesions previously reported from American and African patients. HHV-8 is tropic for the oral mucosa of HIV-infected persons, and HHV-8 variants, though diverse, may be geographically restricted.

Amino Acid Sequence↗
PubMed1997

Antibodies to epithelial components in oral lichen planus (OLP) associated with hepatitis C virus (HCV) infection.

Oral lichen planus (OLP) is a common chronic inflammatory disorder sometimes associated with hepatitis C virus (HCV) infection. An increased prevalence of autoimmune markers has been reported in patients with HCV infection. The aim of the present study was to determine, by conventional indirect immunofluorescence, the nature and frequency of circulating antibodies to epithelial antigens in the sera of HCV-positive patients who also have OLP. The study comprised four groups: 14 patients with OLP and HCV infection. 14 HCV-seronegative patients with OLP, 21 HCV-seropositive patients without OLP and 18 healthy controls. We found a significant association between the concomitance of OLP and HCV infection and the presence of such antibodies. It is concluded that some patients with HCV-associated OLP may have circulating antibodies to epithelial antigens, although their precise aetiological role in the development of this disease in HCV infection remains unknown.

Antiviral Agents↗
PubMed1997

HCV genotypes in Italian patients with HCV-related oral lichen planus.

Hepatitis C virus (HCV) has high genomic variability and since its discovery, six different "types" and an increasing number of "subtypes" have been reported. HCV genotype may influence viral replication, natural history of disease and response to therapy. Recently, an association between lichen planus (LP) and HCV infection has been suggested, as there is an increased frequency of HCV infection among some groups of patients with LP, in particular from Italy and Japan. These results have not been confirmed by other reports from different geographical areas. Since HCV genotypes have a heterogeneous geographical distribution, we have determined by restriction fragment length polymorphism the genotypes of 39 HCV-seropositive Italian patients with oral LP in order to establish whether the association between LP and HCV infection is influenced by HCV subtype. Of the 33 (84.6%) viraemic patients, 17 (51%) were infected by HCV subtype 1b, 9 (27%) were infected by HCV subtype 2a, 2 by subtype 1a and 1 by subtype 2b. In four cases the gel patterns were uninterpretable. This distribution of HCV genotypes is similar to that reported in recent studies of Italian HCV-seropositive patients of unknown LP status. It is concluded from this small sample that the association of lichen planus with HCV infection and its differential geographic distribution is unlikely to be due to infection by a particular HCV genotype.

Adult↗
PubMed1997

Breath odor: etiopathogenesis, assessment and management.

Oral malodor is a significant social disability which usually has a local cause, particularly arising from the oral flora. Malodor may arise from the lingual or periodontal flora, gram-negative anaerobes being the main organisms capable of releasing sulphur compounds from the putrefaction of debris and other material. Volatile sulphur compounds, cadaverine and other substances appear responsible for much of the malodor. Systemic disease may underlie some cases of oral malodor. The objective assessment of malodor is still best performed by the human sense of smell (organoleptic method) but more quantifiable measures are being developed.

Bacterial Physiological Phenomena↗
PubMed1997

Hepatitis C virus infection and lichen planus: a short review.

OBJECTIVE: To review the current literature regarding the association of lichen planus (LP) and liver disease, with particular attention to the association of the oral variant of the disease with hepatitis C virus (HCV) infection. MATERIALS AND METHODS: Available literature of the possible association of LP with systemic disorders, in particular chronic hepatic disease, has been reviewed. RESULTS: LP is sometimes associated with infectious or autoimmune disease and/or neoplasia, however an aetiological association between LP and these disorders seems unlikely. A more consistent association exists between LP and chronic hepatic disease. The precise cause of this association is not known. However, in the last 6 years a notable association between HCV infection and LP has been observed, particularly in patients in Spain, Italy and Japan. The pathogenesis of this possible HCV-associated LP is not known, but it may involve a cell mediated response to an altered epithelial antigen. CONCLUSION: There is now evidence to suggest a significant association between HCV infection and LP in some groups of patients.

Epithelium↗
PubMed1997

Detection of human herpesvirus-8 DNA in oral ulcer tissues of HIV-infected individuals.

OBJECTIVE: To determine the frequency of detection of human herpesvirus-8 (HHV-8) in HIV-related oral ulcers. DESIGN: Analysis of archived biopsy material. METHODS: Nested polymerase chain reaction of DNA extracts. RESULTS: HHV-8 DNA was detected in six of 10 oral ulcers of HIV-positive patients without oral Kaposi's sarcoma (KS) lesions and five of 11 oral KS lesions. The positive non-KS samples were derived from various oral sites. CONCLUSIONS: In HIV-positive people, HHV-8 can infect oral tissues that are not affected by KS.

AIDS-Related Opportunistic Infections↗
PubMed1997

Spanish dental students knowledge of oral malignancy and premalignancy.

BACKGROUND: In view of the gradual rise in oral malignancy in Europe, there is an increased need for undergraduate dental students to have some appropriate training in the recognition of the signs and symptoms of oral Premalignancy and malignancy, and be aware of the appropriate early management of patients with such oral lesions. The present study outlines the results of a pilot study to determine the knowledge and awareness of a cohort of undergraduate dental students in Spain regarding the management of oral premalignancy and malignancy. METHOD: In March 1997 a self-administered questionnaire (SAQ) addressing student's knowledge, opinions, and related aspects of screening and detection of oral malignancy and premalignancy, was mailed to 200 undergraduate dental students in two Spanish Universities. The present report details the responses of this cohort of undergraduates. Statistical analysis of the data was performed using the chi(2) test and the results were considered significant when P < 0.05. RESULTS: 37.0% of the respondents were male and 63.0% female. Almost all of the respondents (99.0%) had attended general dental congresses and 81.5% had attended specific courses on oral malignancy and premalignancy. Only 20% of undergraduate students had witnessed at least one patient with oral malignancy. Squamous cell carcinoma (SCC) was the most frequently observed (94.4%) oral tumour. 79% of the respondents had examined or witnessed at least one patient with a potentially malignant lesion. Leukoplakias were the most commonly observed (80.0%) premalignant lesions. 5th year students were more likely to have performed a biopsy than 4th year students (P < 0.05), particularly male students (P < 0.005). 40.0% of respondents believed that the lower lip was the most common site of an oral cancer; almost half realised that a tumour could have a speckled appearance. 79% to 82% of the respondents indicated that tobacco and alcohol were the principal causes of oral SCC, but 34.6% suggested that HIV disease was a risk factor for oral SCC. Almost all respondents routinely recorded the tobacco or alcohol consumption of patients and would offer advice to patients regarding modification of these habits. 64.0% of undergraduates suggested that clinical screening at intervals of 6 to 12 months was an effective means of diagnosing oral premalignant and malignant lesions, and almost all considered oral health promotion to be an effective means of reducing oral cancer mortality. CONCLUSIONS: Undergraduate dental students in Spain have limited clinical experience or knowledge of related aspects of oral premalignant and malignant lesions, and they may fail to recognise appropriate signs and symptoms and aetiological factors of such disease.

Adult↗
PubMed1996

Computer assisted learning (CAL) of oral manifestations of HIV disease.

General dental practitioners (GDPs) in the UK may wish additional education on relevant aspects of human immunodeficiency virus (HIV) disease. The aim of the present study was to develop and assess a computer assisted learning package on the oral manifestations of HIV disease of relevance to GDPs. A package was developed using a commercially-available software development tool and assessed by a group of 75 GDPs interested in education and computers. Fifty-four (72%) of the GDPs completed a self-administered questionnaire of their opinions of the package. The majority reported the package to be easy to load and run, that it provided clear instructions and displays, and that it was a more effective educational tool than videotapes, audiotapes, professional journals and textbooks, and of similar benefit as post-graduate courses. The GDPs often commented favourably on the effectiveness of the clinical images and use of questions and answers, although some had criticisms of these and other aspects of the package. As a consequence of this investigation the package has been modified and distributed to GDPs in England and Wales.

Adult↗
PubMed1996

Hepatitis C virus (HCV)--an occupational risk to dentists?

Hepatitis B virus has long been regarded as an occupational hazard in dentistry. However, as the availability of effective vaccination has reduced the risk of HBV infection, so dental staff have become aware of the potential risk of transmission of hepatitis C virus during dental treatment. This article outlines current relevant data suggesting that nosocomial transmission of HCV in dentistry is unlikely.

Dentists↗
PubMed1996

Demographics of HIV-infected persons attending a dental clinic.

The demographics of 147 HIV-infected persons attending a special care dental clinic in South West England are reported. The majority of attendants were homosexual/bisexual males, reflecting the UK epidemiology of HIV disease at the time of study. There was a substantial rise in patient numbers from 1988 onwards but patients often did not reveal their route of HIV acquisition or increasingly had acquired HIV disease via heterosexual routes. Patients were usually referred for routine dental treatment, not HIV-related oral disease. The HIV-infected patients generally attended the clinic irregularly, despite being offered many appointments. It is concluded that most patients with HIV disease attend clinics for routine dental care, yet many may be unable or unwilling to attend regularly.

Adolescent↗