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Biomedical subjects

N W Johnson

Publications and source records attributed to N W Johnson.

At least 73 records · Page 4Linked to original sources
PubMed1997

Evaluation of multiple micronutrient supplementation in the management of oral submucous fibrosis in Karachi, Pakistan.

Oral submucous fibrosis (OSF) is an oral precancerous condition characterized by symptoms such as intolerance to spicy food, altered salivation, progressive difficulty in opening the mouth, and signs like vesiculation, ulceration, blanching, rigidity, and stiffening of the oral mucosa and depapillation and altered mobility of the tongue. It is seen mostly among people of Indian subcontinent origin. The major structural change is extensive fibroelastic scarring of the lamina propria and deeper connective tissues. A combination of micronutrients (vitamins A, B complex, C, D, and E) and minerals (iron, calcium, copper, zinc, magnesium, and others) was evaluated for its efficacy in controlling the symptoms and signs of OSF in 117 compliant subjects in Karachi, Pakistan, in a single-arm preliminary study. The subjects received supplementation for one to three years. Significant improvement in symptoms, notably intolerance to spicy food, burning sensation, and mouth opening, was observed at exit. The interincisor distance deteriorated in 11 subjects (10%) at exit; it was stable in 56 subjects (49%) and improved in 48 (41%). The mean interincisor distance was 19.1 +/- 10.8 (SD) mm at exit compared with 16.2 +/- 7.5 mm at baseline. A significant proportion of concomitant lesions like leukoplakia also regressed at exit. The major outcome from this study was a beneficial clinical response in subjects with OSF to multiple micronutrient intervention, which justifies its further evaluation in well-designed randomized controlled trials in other settings in South Asia.

Adolescent↗
PubMed1997

Localised oral histoplasmosis lesions associated with HIV infection.

Opportunistic fungal infections account for a significant amount of morbidity associated with HIV disease. We report here a case of localised oral histoplasmosis without evidence of disseminated disease in a patient who lacked stigmata of HIV disease at the time of initial presentation. The diagnosis is based on histology with special stains, complement fixing antibodies in serum, and culture of the organism from fresh tissues. Activation of subclinical disease following an infection in Uganda may explain the development of these exophytic oral lesions in this British resident.

AIDS-Related Opportunistic Infections↗
PubMed1997

Increased titre and avidity of IgG antibodies to Porphyromonas gingivalis whole cells and a cell surface protein in subjects with adult periodontitis.

The titre and avidity of IgG antibodies to Porphyromonas gingivalis whole cells and a 47 kDa cell surface protein were determined in serum samples taken from 20 subjects with adult periodontitis and 20 controls, matched for age, gender, ethnic origin and oral hygiene status. Antibody titres were measured by ELISA and antibody avidity was determined by a chaotrope-dissociation ELISA. Avidity was defined as the molarity of chaotrope required to reduce absorbance by 50% (ID50). The mean IgG antibody log titre to whole cells (8.29 vs. 6.92; p < 0.01) and to the 47 kDa antigen (7.61 vs. 6.77; p < 0.05) were higher in cases than in controls. Mean IgG antibody avidity to whole cells (4.59 vs. 2.47; p < 0.001) and to the surface protein (2.54 vs. 1.67; p < 0.001) were also higher in cases than in controls. In cases, IgG antibody titre was highly correlated with avidity for both whole cells (r = 0.878; p = < 0.001) and the 47 kDa protein (r = 0.683; p < 0.001). There was a weaker positive correlation between the titre and the avidity of antibody to whole cells (r = 0.591; p < 0.01) in the control population but antibody titre and avidity for the 47 kDa sonicate antigen were not correlated in the controls (r = 0.104). We conclude that many patients with adult periodontitis have effective humoral immunity to P. gingivalis. However, in up to half the patients with adult periodontitis, antibody titres and avidities were low and similar to control values, indicating either susceptibility due to poor host response or that disease is not associated with this particular pathogen.

Adult↗
PubMed1997

Our third year.

Explore the source record for details and available documents.

Europe↗
PubMed1997

Important differences in clinical data from third, second, and first generation periodontal probes.

This study compared relative attachment levels (RAL) and probable crevice depths (PCD) from 6 periodontal probes (1 third, 4 second, and 1 first generation). A single clinician recorded RAL and PCD in 6 patients with chronic adult periodontitis (mean age 48.2 years) during two visits (interval: 1 week) using a Latin square examination order. Replicate measurements were recorded at the 4 interproximal sites of the Ramford index teeth to examine intra-probe differences. Additional single measurements were recorded at similar sites of units 11, 26, 31 and 46 to investigate interprobe differences. Intra-probe RAL and PCD reproducibility was < or = 1 mm at > 94% of the sites. All intra-probe Pearson correlation coefficients were > 0.85 (P = 0.00). Inter-probe RAL and PCD agreement was < or = 1 mm at > 49% of the sites for RAL and > 61% of the sites for PCD. All inter-probe Pearson correlation coefficients were > 0.42 (P = 0.00) for RAL and > 0.49 (P = 0.00) for PCD. Analyses of variance showed significant differences in RAL and PCD between the first generation probe and the second generation probes (P < 0.005); in RAL between the third generation probe and the first and second generation probes (P = 0.0354); and in PCD between the third generation probe and the first and second generation probes (P = 0.0475). Inter-probe differences were clinically significant in the recorded percentages of pockets > or = 4 mm and > or = 6 mm. Significant inter-probe differences were found in RAL and PCD which have clinical importance in data interpretation and comparison.

Adult↗
PubMed1997

Option-4 algorithm for automated disc probe: reduction in the variance of site-specific relative attachment level measurements.

Physical periodontal measurement is plagued by many confounders which result in aberrant values. Replicate measurements can reduce the number of aberrant values, the measurement error, and the variance of site-specific measurements. This study aimed to reduce the variance of site-specific measurements by using a new clinical algorithm (the Option-4 algorithm) for an automated disk probe. A single clinician recorded full-mouth relative attachment levels (RAL) at one visit in 32 patients (mean age 45.5 years) with moderately advanced chronic adult periodontitis. RAL was recorded over two passes at six sites per tooth (4,675 sites). The algorithm accepted the first and second pass RALs (RAL1 and RAL2) if their difference was < or = 1 mm, otherwise a maximum of two further RALs (RAL3 and RAL4) were recorded until the difference between any two RALs was < or = 1 mm (SAL1 and SAL2): 4,048 sites (86.6%) required two recordings, 580 sites (12.4%) required three recordings and 47 sites (1%) required four recordings. Correlation coefficients for RAL1 and RAL2 and SAL1 and SAL2 (4,675 sites) were both > or = 0.91 (P = 0.00). Site-specific variances were calculated for RAL1 and RAL2 and SAL1 and SAL2. The mean of the RAL1/RAL2 site-specific variances (A) was 0.45 mm2 (range 0.00 mm2 to 35.28 mm2) whilst the mean of the SAL1/SAL2 variances (B) was 0.09 mm2 (range 0.00 mm2 to 0.5 mm2): the respective medians were 0.08 mm2 and 0.02 mm2. The study demonstrated high intra-examiner RAL reproducibility. The Option-4 algorithm produced an 80% reduction in the mean site-specific variance of RAL1/RAL2 (Y) and a 75% reduction in the median site-specific variance of RAL1/RAL2 (y = [(A - B)/A] x 100).

Adult↗
PubMed1997

Oral and dental health in alcohol misusing patients.

Dental and oral health and their relationship to nutritional status among a group of alcohol misusers (n = 107) from south London is reported. The Alcohol Use Disorders Identification Test (AUDIT) questionnaire was validated as an accurate and reliable screening questionnaire for use in alcohol misuse detection by a dentist. Half of the study population consumed >200 units of alcohol/week, and 80% were heavy smokers. A high incidence of tooth wear and trauma to the dentition was recorded. Eight subjects had oral mucosal lesions, including two previously treated carcinomas. The dental health in alcoholics overall was not compromised, but nutritional impairment (body mass index and reduced midarm muscle circumference) was associated with periodontal lesions. Oral mucosal health of alcoholics is of concern, particularly in heavy smokers. The interrelationships between dental-oral health and alcohol-tobacco usage have implications for preventative counseling in this patient group.

Adult↗
PubMed1996

Management of potentially malignant oral mucosal lesions by consultant UK oral and maxillofacial surgeons.

This paper describes the results of a recent survey carried out under the auspices of the Professional Education and Evaluation Subgroup of the UK Working Group on Screening for Oral Cancer and Precancer. The aim of this survey was to assimilate information regarding currently used management options of potentially malignant oral lesions as a basis from which to rationalise our future approach to their management. The survey has confirmed that variation exists among oral and maxillofacial consultants in their approaches and a more formal approach to management may therefore be indicated.

Data Collection↗
PubMed1996

Risk factors associated with Epstein-Barr virus replication in oral epithelial cells of HIV-infected individuals.

OBJECTIVE: To examine risk factors associated with Epstein-Barr virus (EBV) replication in the oral epithelium of an HIV-infected cohort. DESIGN: Longitudinal study of behavioural, medication and immunological parameters of HIV-1-seropositive outpatients attending a genitourinary clinic. Outcome measure was EBV DNA positivity in curetted oral squames, as detected by in situ hybridization. Logistic regression for repeated observations of the same individuals was used to analyse how risk changed over time. RESULTS: Fifty six individuals were studied; 158 patient-visits were made in total (mean, 2.8). Of 137 samples curetted from the tongue, 36 were positive for EBV DNA. Recreational drug use, oral sexual practices, therapy with zidovudine and aciclovir, and changes in CD4 and total lymphocyte counts were not associated with changes in risk. Alcohol drinking, elevated CD8 lymphocyte counts and fluconazole therapy were associated with a decreased risk, and cigarette smoking with increased risk. CONCLUSION: Behavioural and HIV-specific immunological changes may play important roles in promoting and affecting the course of oral EBV replication. Rigorous anticandidal therapy and avoidance of cigarette smoking may retard the development of oral hairy leukoplakia.

AIDS-Related Opportunistic Infections↗
PubMed1996

Strengths and weaknesses of screening programmes for oral malignancies and potentially malignant lesions.

Screening for oral cancer is in an early stage of development. No randomized controlled trials have been undertaken to determine the impact of screening on mortality or even on interim outcomes such as incidence or down-staging. Until such data are available, mass screening for oral cancer is not recommended as public health policy. Case finding studies to identify individuals at risk because of life-style, and to detect potentially malignant oral mucosal changes followed by appropriate intervention may, however, reduce the future incidence of oral cancer. Where manpower is available, opportunistic screening focused on high-risk subjects may be beneficial.

Humans↗
PubMed1996

Sensitivity and specificity of OraScan (R) toluidine blue mouthrinse in the detection of oral cancer and precancer.

The efficacy of 1% toluidine blue in the identification of oral malignancies and potentially malignant oral lesions was evaluated among a group of Asian patients (n = 102) with undiagnosed oral mucosal lesions and conditions (n = 145). The trial, utilising a ready-to-use kit, was controlled by histopathologic evaluation of a total of 87 dye-retained or dye-negative lesions. Eighteen oral carcinomas all retained the dye and there were no false negatives, yielding a test sensitivity of 100%. Eight of 39 oral epithelial dysplasias were toluidine blue-negative, giving a false negative rate of 20.5% and a sensitivity of 79.5% for oral epithelial dysplasias. The specificity of the technique was low (62%). Five dysplastic lesions were detected solely by the kit and this suggests that the method is valuable for surveillance of high-risk subjects in addition to its remarkable sensitivity in the detection of invasive carcinoma.

Asia↗
PubMed1996

Toombak-associated oral mucosal lesions in Sudanese show a low prevalence of epithelial dysplasia.

Clinical (n = 281) and histopathological (n = 141) characteristics of toombak-associated oral mucosal lesions detected in an epidemiological study in northern Sudan in 1992/93 are described. The lesional site in the majority of toombak users was the anterior lower labial groove and the lower labial mucosa. 4 degrees (1-4) of clinical severity of lesions, similar to those used to characterise Swedish snuff-dipper's lesion, were applied. An association between the severity of mucosal lesions and a longer lifetime duration (> 10 years) of toombak use was found, but the severity was not related to the daily frequency of the habit. Parakeratosis, pale surface staining of the epithelium and basal cell hyperplasia were commonly observed, but epithelial dysplasia was infrequent (10/141). The most significant observation was a PAS-positive amorphous deposit between the lamina propria and the submucosa, found in 25/141 biopsies. The clinical and histopathological features of toombak lesions are closely similar to Swedish moist snuff-dipper's lesions and this may reflect the high alkalinity of these products, resulting in an alkaline burn on the oral mucosa following chronic exposure. The low prevalence of epithelial dysplasia implies a low risk of malignant transformation. Nevertheless, the high concentrations of tobacco-specific nitrosamines present in toombak, and the high prevalence of oral cancer in Sudan, mandate biopsy and careful histopathological analysis of any such lesions detected in habitues.

Adolescent↗
PubMed1996

Hereditary and environmental risk factors; clinical and laboratory risk matters for head and neck, especially oral, cancer and precancer.

The continuing high incidence and mortality of squamous cell carcinoma of the upper aerodigestive tract in South Asia, parts of France and central Europe, together with a rising incidence and mortality from a lower base elsewhere in the Western world, stimulates continuing research on risk factors and risk markers. Tobaccos (smoked and smokeless), heavy alcohol consumption, and areca nut remain the dominant risk factors, with confirmation of the protective effects of diets rich in antioxidants. There is emerging evidence of a small, but real, risk associated with occupational and other air pollution, and with family, part of which may be hereditary. Markers in peripheral blood and saliva are underexploited. Clinical staging and histological grading methods continue to be refined, with improved prognostic value, much aided by newer and simpler methods for estimating cell proliferation and apoptosis. Data on the significance of viral genes are still inadequate, but there is good progress describing the epidemiology of chromosomal abnormalities and abberations of a growing list of oncogenes and tumour suppressor genes. Unfortunately, as yet, these have only limited longitudinal or prognostic data.

Alcohol Drinking↗
PubMed1996

Oral health in alcohol misusers.

One hundred and seven chronic alcohol misusers (mean age 42.9 years; range 21-65 years; 80 males) attending four centres in South East London were interviewed on their current and past alcohol consumption. Their nutritional status (body mass index (BMI) and mid arm muscle circumference) was also recorded. Each subject completed a dental and oral mucosal examination. Ninety four per cent of the sample consumed greater than 50 units of alcohol per week and 80 per cent greater than 100 units of alcohol per week. Smoking and alcohol misuse were found to be related, 81 per cent reporting both habits. Neither plaque index scores or mean subject pocket depths were correlated with alcohol consumption but both were positively correlated with the frequency and duration of smoking. Overall mean DMFT was 15.4; age specific mean DMFT and tooth loss of the sample were closely similar to the 1988 United Kingdom adult dental health survey data. The prevalence and severity of tooth wear and attrition were greater in the sample than levels described in the literature and these dental features may prove useful markers to the practitioner. Trauma to teeth and oral mucosae was noted in 25 per cent of the sample. Seven oral mucosal lesions (including one treated carcinoma) were detected; mucosal trauma could have acted as a co-factor. Furthermore, 21 per cent of the alcoholics were malnourished (BMI < 20). It is concluded that, unlike several reports from the United States, dental health in this sample of alcoholics is not compromised; however mucosal health is a cause for concern.

Adult↗