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Biomedical subjects

S R Porter

Publications and source records attributed to S R Porter.

At least 91 records · Page 5Linked to original sources
PubMed1998

No evidence of HCV infection or liver disease in British patients with oral lichen planus.

An association between chronic hepatic disease and/or hepatitis C (HCV) infection and lichen planus (LP) has been described in patients from Italy, Japan and Spain. There are no data on the frequency of the association with HCV in British patients. In the present investigation, the HCV seropositivity and liver function status of 55 British patients with oral LP were assessed and compared with these parameters in 110 healthy control subjects. None of the patients with LP or control subjects had serum IgG antibodies to HCV or had abnormal liver function. It was concluded that while LP may be associated with HCV infection and liver disease in some southern European and other patients, such a co-occurrence was not detected in British patients.

Adult↗
PubMed1998

Hepatitis C virus infection: Review and implications for the dentist.

OBJECTIVE: The purpose of this report was to review the current literature on hepatitis C virus infection, with particular attention to the aspects of interest for dental health care staff. MATERIAL AND METHODS: The authors searched original research and review articles on specific aspects of hepatitis C virus infection, including articles on virology, epidemiology, transmission, diagnosis, natural history, extrahepatic manifestations, therapy and oral aspects of hepatitis C virus infection. The relevant material was evaluated and reviewed. RESULTS: Hepatitis C virus is an RNA virus that is present throughout the world and has major geographic variations. The virus, transmitted mainly by means of blood contact, causes chronic hepatitis in up to 80% of cases and may give rise to hepatic cirrhosis and hepatocellular carcinoma in a significant proportion of patients. Although it is of limited efficacy, interferon alpha is currently the drug of choice in the treatment of the infection. Hepatitis C virus infection is associated with a number of extrahepatic manifestations that may include oral diseases such as lichen planus or sialadenitis. Although there are documented cases of nosocomial transmission to health care workers after percutaneous exposure, the prevalence of hepatitis C virus among dental staff members is probably similar to that in the general population. CONCLUSION: Hepatitis C virus infection is a relatively common infection worldwide (1.4% in the US general population) that causes significant chronic hepatic disease. The dentist is thus likely to face a growing number of patients with a diagnosis of hepatitis C virus infection. For this reason it is essential for dental health care workers to be aware of the principal features of the disease and of its oral and dental implications.

Carcinoma, Hepatocellular↗
PubMed1998

Human herpes virus 8 (Kaposi's sarcoma herpesvirus).

Human herpes virus 8 (HHV-8) is a recently discovered herpesvirus related to Herpesvirus saimiri and Epstein-Barr virus (EBV). It has been assigned to the Rhadinovirus genus (gamma-2 herpesvirus) on the basis of its genomic sequence and structure. HHV-8 is the first member of this genus known to infect humans and it is now evident that it is the likely cause of Kaposi's sarcoma (KS). The virus is present in endothelial and spindle cells of KS, and in HIV disease the presence of HHV-8 in peripheral blood, and/or serum IgG antibodies to HHV-8, predicts the development of AIDS-related KS. HHV-8 can also infect CD19 + B cells and is of aetiological significance in the development of body cavity B cell lymphomas of AIDS. Of note, the translation products of viral open reading frames (ORFs) reveal HHV-8 to be a molecular pirate, capable of producing homologues of several human gene products that may result in alterations in cell cycle arrest, inhibit apoptosis and cell-mediated immune responses, and thus provide the potential for tumour production.

Genitalia, Male↗
PubMed1998

Immunohistochemical and serological comparison of idiopathic and hepatitis C virus-associated forms of oral lichen planus.

The oral form of the inflammatory disease lichen planus occurs spontaneously due to unknown aetiological factors. However, it has recently been observed to occur with increased frequency in patients infected with the hepatitis C virus. Because of the prominent role of adhesion molecules in immune cell interactions, we have compared the expression of these antigens in the hepatitis C virus-associated and idiopathic forms of the disease. The results show similar patterns of expression of very late activation antigen-4, lymphocyte function-associated antigen-3 and intercellular adhesion molecule-1, but relatively elevated levels of these antigens in oral lichen planus patients with no hepatitis C virus infection. In addition to differences in Langerhans cell distribution, serum levels of "soluble" intercellular adhesion molecule-1 as well as immunoglobulin G were significantly increased in the hepatitis C virus-associated group. These findings show that there are some differences in the lesional and systemic immune reactivities of the two types of oral lichen planus which may be related to possibly distinct pathogenic mechanisms.

Antigens↗
PubMed1998

Multiple salivary mucoceles in a young boy.

A rare case of multiple mucoceles in a 4-year-old boy is reported. The patients presented with multiple sessile swellings on his lower lip, with no obvious local aetiology. The patient was otherwise well. The lesions were excised surgically and histopathological examination confirmed the lesions to be extravasation-type mucoceles. The article includes a brief review of mucoceles.

Child, Preschool↗
PubMed1998

Diversity of naturally occurring Epstein-Barr virus revealed by nucleotide sequence polymorphism in hypervariable domains in the BamHI K and N subgenomic regions.

The extent of nucleotide sequence microheterogeneity varies among subgenomic regions of Epstein-Barr virus (EBV). We examined, in EBV-carrying lymphoid cell lines, the extent of polymorphism in EBV DNA fragments amplified from the BamHI E, K, N and Z regions, and then investigated the diversity of the more hypervariable regions in tissues and body fluids. In cell lines, sequence dissimilarities in a genotype-specifying fragment of the EBNA-3C gene varied from < 1-4% within each genotype; dissimilarities in the first intron of the BZLF- 1 gene were < 2% within each genotype. By contrast, dissimilarities in a C-terminal unique domain of the EBNA-1 gene, and in a fragment that encompasses and is upstream of the LMP-1 start codon, varied between 2 and 7% and were not genotype-specific. The sequence diversity in BamHI K and N regions was then examined in tissues and body fluids by single-strand conformation polymorphism (SSCP) analysis and cycle sequencing. Extensive inter-host diversity was observed, whether the host was co-infected by human immunodeficiency virus (HIV) or not. In the oral cavity of HIV-infected patients, inter-compartmental EBV diversity could be demonstrated, even between sites that were anatomically proximate. Studies of BamHI K clones derived from EBV in oral lesions revealed infection by multiple variants. Identification of hypermutable loci within the EBV genome such as those located in the BamHI K and N regions should permit fine discrimination of individual EBV variants.

Amino Acid Sequence↗
PubMed1998

Detection of Epstein-Barr virus in oral scrapes in HIV infection, in hairy leukoplakia, and in healthy non-HIV-infected people.

Epstein Barr virus (EBV) has been implicated in the pathogenesis of oral hairy leukoplakia (OHL). EBV is normally detected by lesional biopsy. The objectives of this study were to examine oral scrapes containing squamous epithelial cells (squames) from HIV-infected people with and without clinical lesions of OHL, and from healthy non-HIV-infected controls, for EBV-DNA by the polymerase chain reaction (PCR). EBV-DNA was detected in 65% of HIV-infected people and 20% of healthy HIV-negative controls but in HIV-infected individuals it was found as frequently in those without OHL as in those with. Moreover, EBV-DNA was not detected in all HIV-infected individuals, nor in all OHL. The results suggest that the presence or absence of detectable EBV-DNA in oral scrapes, though a guide, cannot be regarded as absolutely reliable in the diagnosis or exclusion of OHL.

Adult↗
PubMed1998

HIV topic update: protease inhibitor therapy and oral health care.

Protease inhibitors have been a major advance in the management of HIV disease and have reduced the frequency and severity of many complications, including some oral lesions. They may also be of value in the management of occupational exposures to the virus. However, they may produce adverse effects including oral symptoms such as paraesthesia, taste disturbances and xerostomia, and may interact with a number of drugs used in oral health care. This article summarises the current situation.

Administration, Oral↗
PubMed1998

Recurrent aphthous stomatitis.

Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal disorders. Nevertheless, while the clinical characteristics of RAS are well-defined, the precise etiology and pathogenesis of RAS remain unclear. The present article provides a detailed review of the current knowledge of the etiology, pathogenesis, and management of RAS.

Humans↗
PubMed1997

Human herpesvirus 8 variants in sarcoid tissues.

BACKGROUND: The cause of sarcoidosis is unknown, although mycobacteria have been implicated. We examined sarcoid tissues for human herpesvirus 8 (HHV-8) in addition to mycobacterial genomic sequences. METHODS: Biopsy samples from 17 patients with sarcoidosis were studied (eight transbronchial, 27 lymph node, two skin, and two oral mucosa). We used tissues (n = 137) from 96 patients without sarcoidosis as negative controls. A nested PCR was applied to amplify a segment of open reading frame (ORF) 26 of the HHV-8 genome, and a heminested PCR was to amplify a segment of ORF 25 of HHV-8 and of the 16 S rRNA gene of mycobacteria. Differences in base sequences of the amplified fragments were resolved with single-strand conformation polymorphism and dideoxy sequencing. FINDINGS: HHV-8 ORF 26 DNA was detected in significantly higher proportions of sarcoid than of non-sarcoid tissue samples from lung (8/8 vs 0/54; p < 0.0001), lymph nodes (26/27 vs 6/29; p < 0.0001), skin (2/2 vs 0/17; p = 0.006), and oral tissues (2/2 vs 1/13; p = 0.029). 31 (82%) of the 38 ORF 26 DNA-positive sarcoid specimens were also positive for ORF 25 DNA. For mycobacteria-like 16 S rRNA DNA, the proportion positive was significantly higher in sarcoid than non-sarcoid tissues for lymph node samples (11/27 vs 2/29; p = 0.003) but not for other tissues (lung 3/8 vs 22/54; skin 2/2 vs 15/17; and oral tissues 1/2 vs 0/13). Overall, the prevalence of HHV-8 ORF 26 sequences was higher in sarcoid tissues than in non-sarcoid tissues (p < 0.0001). When patients whose tissues were included in a masked phase of the study were treated as units of analysis, eight of eight sarcoidosis patients were positive for HHV-8 ORF 26 DNA, compared with three of 56 control patients (p < 0.0001); for mycobacteria-like sequences, three of eight sarcoidosis patients were positive, compared with four of 56 controls (p = 0.0464). The HHV-8 ORF 26 sequences, ten of which were unique, could be segregated into four groups according to peptide motifs. In seven of nine patients from whom biopsy samples were taken from various sites, different sequences were recovered. The mycobacterial sequences amplified from sarcoid tissues were also varied, but none was homologous to those of known species. INTERPRETATION: Variant HHV-8 DNA sequences are found in a wide range of sarcoid but not non-sarcoid tissues. Mycobacteria-like 16 S rRNA sequences are more frequently present in sarcoid lymph nodes and not in other tissue types, but do not indicate infection by a particular mycobacterial species.

Adult↗
PubMed1997

Prevalence of HCV infection in health care workers of a UK dental hospital.

OBJECTIVE: To determine the prevalence of hepatitis C virus (HCV) antibodies in a group of dental health care workers (DHCW). DESIGN: Retrospective cross sectional study. SETTING: A UK dental hospital. SUBJECTS AND METHODS: The sera of 167 unselected DHCW were tested for the presence of IgG antibodies to HCV using two, third-generation enzyme-linked immunosorbent assays (ELISA). HCV viremia was determined by reverse transcription polymerase chain reaction (RT-PCR) analysis. RESULTS: Two (1.2%) of the serum samples were found to be anti-HCV positive; one was also viremic. The two antibody-positive subjects were a qualified dental nurse and a student dental nurse, both females, without any known risk factor for HCV acquisition. No dentist was HCV seropositive. CONCLUSIONS: Since the prevalence of HCV infection in the UK general population varies between 0.08% and 0.55%, these results suggest that DHCW, and auxiliary staff in particularly, may have a slightly increased risk of HCV infection.

Adolescent↗
PubMed1997

Early management of dental pain in children and adolescents.

OBJECTIVES: There is little information regarding the initial management of dental pain in children and adolescents. The present study investigated the early management of 155 children and adolescents with dental pain prior to definitive treatment in the Eastman Dental Institute and Hospital for Oral Health Care Sciences, London, UK. METHOD: Prior to the child being examined by a qualified dentist in the casualty department, the accompanying parents or guardians were requested to complete a self-administered questionnaire regarding the duration and severity of pain, presence of swelling, professional advice sought and medication taken. RESULTS: Of the attending children, 83% were in pain, 20% having been in pain for over 1 month. Most parents sought professional health care advice, particularly from a dentist; however, 15% initially obtained advice from a medical practitioner and 5% from a pharmacist. Simple analgesics were taken by 74% of patients; however, these rarely produced complete pain relief. Of concern, 10 children were inappropriately given aspirin, three of whom had taken the aspirin on the advice of a pharmacist. Sixty-seven children received systemic antibiotic therapy; however, 31% of these patients did not have any local swelling. CONCLUSION: It is evident that children and adolescents often receive inappropriate initial treatment for dental pain and may thus suffer unnecessary symptoms for several weeks. There is thus a need to educate healthcare workers more appropriately on aspects of the management of oral pain and to promote oral health care and hence reduce the incidence of caries in children.

Adolescent↗
PubMed1997

Oral lichen planus is not associated with IgG circulating antibodies to epithelial antigens.

Autoantibodies to a number of epithelial components have previously been described in small groups of patients with lichen planus. Recently a group of antibodies to monkey esophagus have been detected in lichen planus related to hepatitis C virus infection. This study has examined the frequency of serum antiepithelial antibodies in a group of patients with idiopathic oral lichen planus and lichenoid drug reactions. Five of 34 patients with idiopathic lichen planus and two of six patients with lichenoid eruptions had circulating antibodies that gave rise to an antinuclear pattern when examined using epithelial tissue. However, these antibodies were present in only low titer and were not specific to a particular clinical presentation of lichen planus or lichenoid drug reaction. It seems likely therefore that such antibodies do not play an important part in the etiopathogenesis of lichen planus, and their detection is unlikely to be beneficial in the diagnosis of this disease.

Adolescent↗
PubMed1997

Serum IgG antibodies to Helicobacter pylori in patients with recurrent aphthous stomatitis and other oral disorders.

OBJECTIVES: To compare the frequency of serum anti-Helicobacter pylori IgG antibodies in patients with recurrent aphthous stomatitis with patients with other oral ulcerative and nonulcerative disorders. STUDY DESIGN: Prospective study of serum IgG antibodies to H. pylori in 75 patients with recurrent aphthous ulcers, 15 patients with other oral ulcerative disorders, 41 patients with other oral mucosal lesions, 27 patients with oral dysaesthesia, and 25 healthy control patients without oral lesions. RESULTS: The frequency of anti-H, pylori seropositivity was not significantly greater in patients with recurrent aphthous stomatitis (30.6%) compared with patients with other ulcerated oral mucosal lesions (33.0%) and controls (24%). CONCLUSIONS: Helicobacter pylori does not appear to be of etiologic significance in the development of recurrent aphthous stomatitis.

Adolescent↗