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Biomedical subjects

N W Johnson

Publications and source records attributed to N W Johnson.

At least 19 recordsLinked to original sources
PubMed2001

Risk factors for squamous cell carcinoma of the oral cavity in young people--a comprehensive literature review.

There have been several reports of a rising incidence of oral cancer from many parts of the world. Although it is well known that oral cancer increases with age, recent trends for a rising incidence particularly relates to cancer of the tongue and mouth in young males. This review critically examines 46 publications devoted to oral cancer in the young adult. Most studies suggest that 4-6% of oral cancers now occur at ages younger than 40 years. Several studies examining risk factors for oral cancer in the young provide evidence that many younger patients have never smoked or consumed alcohol, which are recognised risk factors in older groups, or that duration of exposure may be too short for malignant transformation to occur. Information on many aspects of aetiology for this disease in the young implicating occupational, familial risk, immune deficits and virus infection are meagre. The spectrum of genetic abnormality disclosed is similar to older patients, there is paucity of specific studies involving younger cohorts, but predisposition to genetic instability has been hypothesised as a likely cause. Conflicting evidence is also reported on the sex distribution and outcome compared with older patients. Much work is required to understand the caveats related to global demography, risk factors and their diagnostic and prognostic markers for this disease which might be considered a disease distinct from that occurring in older patients.

Adolescent↗
PubMed2001

The influence of partial and full-mouth recordings on estimates of prevalence and extent of lifetime cumulative attachment loss: a study in a population of young male military recruits.

BACKGROUND: Previous studies have shown that the use of index teeth may underestimate the prevalence of chronic periodontitis in adults. However, there is little information on the effect of using index teeth to estimate the prevalence of early periodontitis in younger adults and the effect this may have on planning treatment needs and health care resources. The aim of this study was to compare full mouth examination with partial examination using index teeth in a group of young British males. METHODS: One hundred subjects aged between 16 and 20 years (mean 17 years) on entry to the study were examined at baseline, 12 months later, and 30 months later. Lifetime cumulative attachment loss (LCAL) > or =1 mm was measured on the mesio-buccal, disto-buccal, mesio-lingual, and disto-lingual surfaces of all teeth, excluding third molars. All data were entered into a database. The indices used to express LCAL were prevalence, defined as the percentage of subjects with LCAL > or =1 mm, 2 mm, or 3 mm, and extent, defined as the percentage of sites with LCAL > or =1 mm, 2 mm, or 3 mm. Two sets of index teeth were chosen to compare with full mouth recordings, Ramfjord index teeth and the Periodontal Index for Treatment (PIT) teeth. RESULTS: The prevalence of LCAL > or =1 mm was similar (approaching 100%) for the full mouth and both partial mouth recordings. However, as LCAL increased from a minimum of 1 to 3 mm, partial mouth recording resulted in an underestimation of the prevalence of disease. LCAL > or =2 mm was underestimated by up to 22% and LCAL > or =3 mm by up to 36%. The extent of LCAL was less affected by partial mouth recording, in that the percentage of sites with no sign of early attachment loss was underestimated by up to 11%. However, the percentage of sites with LCAL > or =1 mm and 2 mm were overestimated by 11% and, 7% respectively. CONCLUSIONS: These data indicate that the use of index teeth in epidemiological studies which include young adults may result in an underestimation of the prevalence of early periodontitis and an overestimation of the extent.

Adolescent↗
PubMed2000

Action on smoking--opportunities for the dental team.

In 1998, the UK government published a White Paper outlining a comprehensive range of measures to reduce smoking rates across the population. In the same year a detailed overview of the evidence base for smoking cessation activities within the NHS was published. Both these documents provide useful information for health professionals interested in developing their roles in smoking cessation and prevention. An increased risk for the development of oral malignancies and a susceptibility for the breakdown of periodontal tissues are the most significant effects of smoking on the mouth. This paper aims to highlight how dentists and their team members can become actively involved in efforts to reduce smoking. Opportunities at both a clinical and public health level are considered.

Dental Staff↗
PubMed2000

A controlled study of relative periodontal attachment loss in people with HIV infection.

OBJECTIVE: To compare the progression of periodontal destruction in people with and without HIV. METHOD: Relative attachment loss on 6 index teeth was compared between 19 people with HIV and 17 people without HIV infection over 12 and 18 month follow ups. RESULTS: The proportions of sites with 1, 2 or 3 mm of relative attachment loss were similar in the study and control groups. Mean maximum relative attachment loss was similar in both groups after 12 months but greater in the study group after 18 months. CONCLUSIONS: The data are not compelling evidence of greater periodontal destruction associated with HIV infection. Large scale cohort studies or meta-analyses would be more conclusive.

Adult↗
PubMed2000

Raised tissue copper levels in oral submucous fibrosis.

Oral submucous fibrosis (OSF) is a well-recognised-potentially malignant condition of the oral cavity associated with areca nut chewing. Areca nut has been shown to have a high copper content compared to other commonly eaten nuts, and chewing areca nut for 5-30 min significantly increases soluble copper in whole mouth fluids. Our aims were to determine if tissue and serum concentrations of copper were raised in patients with OSF as a result of chewing areca nut. A panel of buccal mucosal biopsies from patients with OSF from Nagpur, India, was used to measure the tissue concentrations of copper by mass absorption spectrometry (MAS). By MAS, the mean tissue copper level was 5.5+/-2.9 microg/g in the OSF specimens (n=11) compared with 4+/-1.9 microg/g in the non-areca chewing controls (n=7) (P=0.2). Energy dispersive x-ray microanalysis (EDX) was used to identify the presence and distribution of the metal element. EDX showed distinct peaks corresponding to copper (Kalpha 8.04 keV; Kbeta, 8.91 keV) in the epithelium (21/23) and in the connective tissue (17/23) of the OSF specimens compared to spectra obtained from control oral biopsies from non-areca chewing subjects (n=7). These findings were confirmed by secondary ion mass spectrometry (SIMS) analysis in a small number of samples. Serum copper (17.23+/-1.80 pmol/l), caeruloplasmin (0.32+/-0.04 g/l) levels and urinary copper (0.52+/-0.26 micromol/l) in OSF patients (n=14) were within the laboratory reference ranges. The finding of copper in OSF tissue supports the hypothesis of copper as an initiating factor in OSF, playing a role in stimulating fibrogenesis by the upregulation of lysyl oxidase activity.

Adolescent↗
PubMed2000

The epidemiology of mouth cancer: a review of global incidence.

Mouth cancer (143-145 ICD-9) is a major health problem in many parts of the world. While its incidence is relatively low in most western countries there are some important exceptions to this trend: on the Indian subcontinent and in other parts of Asia it remains one of the most common forms of cancer. This review article summarises the global incidence of mouth cancer using cancer maps. Data have been compiled from the latest edition of Cancer Incidence in Five Continents and recent studies from various locations around the world. Significant geographic variation is noted in the incidence of mouth cancer, with high rates reported for the Indian subcontinent and parts of Asia (male incidence rates in excess of 10 per 100,000 per annum). It is also noted that as with other forms of oral cancer, the majority of population-based data for mouth cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. Mouth cancer remains a serious health problem in many parts of the world with many regions reporting increasing incidence rates particularly in males. Ongoing research into the aetiologic risk factors associated with this disease must remain a very high priority if the causes of mouth cancer are to be established and disease control protocols introduced widely.

Asia↗
PubMed2000

The epidemiology of tongue cancer: a review of global incidence.

The tongue (141 ICD-9) is the most common intraoral site for cancer in most countries, however its global epidemiology shows significant geographic variation. This review paper summarises the global incidence of cancer of the tongue using cancer maps and references to recent studies from various locations. Tongue cancer remains a serious health problem in many countries including India (male incidence rates up to 6.5 per 100,000 per annum) and parts of Europe (male incidence rates in France up to 8.0 per 100,000 per annum). It is noted that as with other forms of oral cancer the majority of population-based data for tongue cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. The tongue remains the most common intraoral site for oral cancer worldwide and in a number of countries it is a serious public health problem with significant morbidity and mortality. While the incidence of tongue cancer appears to be stable or falling in some regions of the world, in other areas it is rising, particularly among younger people.

Age Factors↗
PubMed2000

Prevalence and incidence of oral lesions--the changing scene.

A range of oral mucosal and periodontal lesions is associated with HIV infection and HIV disease progression. These are often symptomatic and require treatment in themselves, and also have a diagnostic and prognostic role in the management of the underlying HIV disease. These lesions have been broadly divided into: (a) those strongly associated with HIV such as oral candidoses, oral hairy leukoplakia and Kaposi's sarcoma; (b) those less strongly associated such as swellings of the major salivary glands; and (c) those least commonly associated such as recurrent aphthous ulcers. Overall the prevalence and severity of these lesions inversely correlate with the level of immunosuppression. With the passage of time, there has been improved understanding of the disease pathogenesis resulting in the development of new drugs to combat this infection. Medication has changed from monotherapy to current triple combination therapy (Highly Active Anti-Retroviral Therapy). This review looks at the impact of changing therapy on the prevalence of the various oral lesions associated with HIV. It finds a decrease in the prevalence of the oral lesions in the era of combination therapy as compared to earlier periods. It also shows a change in the types of lesions which predominate with those previously placed amongst the strongly associated lesions no longer being predominant in the era of combination therapy where such treatment is available.

AIDS-Related Opportunistic Infections↗
PubMed2000

Oral lesions and conditions associated with human immunodeficiency virus infection in 300 south Indian patients.

BACKGROUND: Human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) is a major health problem in India. The National AIDS Control Organisation (NACO) of India reports a seropositivity of 25.03 per thousand for the whole country, as of October 1999. In spite of this high prevalence there are very few reports of oral lesions and conditions in Indian HIV/AIDS patients, which are important in early diagnosis and management of these patients. OBJECTIVE AND SETTING: The present report describes the oral lesions in 300 HIV positive symptomatic patients presenting to us at RAGAS-YRG CARE, a non-governmental organisation in Chennai, South India, over a period of 9 months in 1998. METHOD: Lesions were diagnosed on clinical appearance using international criteria. RESULTS: Of the 300 patients 89% had acquired the infection through heterosexual contact. There were 205 males and 95 females, aged from 7 months to 72 years. Forty-seven percent of the patients were in the age group 21-30 years. CD4 counts were ascertained for 105 patients, 64 (62%) had CD4 counts < or = 200. A total of 217 (72%) of the 300 patients had some oral lesion when examined. Gingivitis (47%) and pseudomembranous candidiasis (33%) were the most common oral lesions. The other oral lesions seen were oral mucosal pigmentation (23%), erythematous candidiasis (14%), periodontitis (9%), angular cheilitis (8%), oral ulcers (3%), oral hairy leukoplakia (3%), hyperplastic candidiasis (1%), oral submucous fibrosis (2%) and one case of leukoplakia. CONCLUSIONS: Oral lesions occur commonly in HIV infection. A comprehensive oral examination may not only suggest HIV disease but may also be useful in monitoring the disease progression. This is a cost-effective procedure, which may be useful in screening large populations in developing countries like India.

AIDS-Related Opportunistic Infections↗
PubMed1999

An alarming lack of public awareness towards oral cancer.

OBJECTIVE: To determine public awareness and knowledge of oral cancer in Great Britain. DESIGN: The respondents were selected according to a systematic probability sample designed to be representative of all adults in Great Britain (GB). The overall design was similar to previous omnibus surveys carried out by National Opinion Poll (NOP). The survey was carried out in ten regions of GB in September 1995 and was commissioned by the Health Education Authority (HEA). SUBJECTS AND METHODS: A random sample of 1,894 members of the public over the age of 16 years were asked in face-to-face interviews their knowledge relating to cancer, with particular reference to oral cancer, its causes and those at high risk and general attitudes to cancer. RESULTS: Oral cancer was one of the least heard of cancers by the public with only 56% of the participants being aware, whereas 96% had heard of skin cancer, 97% lung cancer and 86% cervical cancer. There was a 76% awareness of the link between smoking and oral cancer but only 19% were aware of its association with alcohol misuse. Whereas 94% agreed that early detection can improve the treatment outcome, a disheartening 43% believed that whether a person developed a cancer or not was a matter of chance and therefore was unavoidable. CONCLUSIONS: This survey highlights a general lack of awareness among the public about mouth cancer and a lack of knowledge about its causation especially the excess risk associated with alcohol. RECOMMENDATIONS: There is a clear need to inform and educate the public in matters relating to the known risk factors associated with oral cancer. A media campaign informing the public about oral cancer is clearly required. The need for the reduction in the incidence of oral cancer should be included in 'Our healthier nation' targets. An overall health promotion strategy to reduce cancers should include oral cancer as a priority. In addition the European Code against Cancer which aims to improve prevention, the early detection of oral cancer and the necessity for fast track referral should be made more widely known. Recognition of oral cancer in local strategies for oral health should be encouraged.

Adolescent↗
PubMed1999

Cancer of mouth, pharynx and nasopharynx in Asian and Chinese immigrants resident in Thames regions.

Studies on migrants can generate important clues on the etiology of cancer. The purpose of the present study was to determine the relationship between ethnic origin and the incidence of oral and pharyngeal cancers among residents of the Thames regions in southern England. Records from the Thames Cancer Registry during the period 1986-91 were examined and south Asians and Chinese ethnic immigrants flagged using their place of birth and names. Computation of relative incidence among head and neck cancers (n = 7222) showed that oral cancer was significantly higher among Asians (95/232 = 40.9%) and nasopharyngeal cancer among Chinese (45/67 = 67.2%). Some differences in the intra-oral site of cancer and ethnic origin were noted. The ethnic migrants were significantly younger (Asians 51.6 +/- 34.8 years, Chinese 47.6 +/- 14.8 years) compared to the rest of the population (64.8 +/- 15.6 years) at the time of cancer diagnosis (p = 0.0) but no significant differences were found for the stage of presentation. The mean survival period for a cancer of the head and neck was 2.2 years and significant differences in cumulative rates of survival were noted among the three groups studied (p = 0.003). A strong correlation was noted between the incidence of oral cancer and local authorities with a high percentage of Asian residents. The south Asian and Chinese ethnic minorities constitute important high risk groups for oral and nasopharyngeal cancer, for whom targeted prevention is indicated.

Adult↗
PubMed1999

Option-4 algorithm for Florida pocket depth probe: reduction in the variance of site-specific probeable crevice depth measurements.

Clinical periodontal measurement is plagued by many sources of error which result in aberrant values (outliers). This study sets out to compare probeable crevice depth measurements (PCD) selected by the option-4 algorithm against those recorded with a conventional double-pass method and to quantify any reduction in site-specific PCD variances. A single clinician recorded full-mouth PCD at 1 visit in 32 subjects (mean age 45.5 years) with moderately advanced chronic adult periodontitis. PCD was recorded over 2 passes at 6 sites per tooth with the Florida Pocket Depth Probes, a 3rd generation probe. The option-4 algorithm compared the 1st pass site-specific PCD value (PCD1) to the 2nd pass site-specific PCD value (PCD2) and, if the difference between these values was >1.00 mm, allowed the recording of a maximum of 2 further measurements (3rd and 4th pass measurements PCD3 and PCD4): 4 site-specific measure-meets were considered to be the maximum subject and tissue tolerance. The algorithm selected the 1st 2 measurements whose difference was < or = 1.00 mm (SPCD1 and SPCD2). If no 2 measurements had a difference < or = 1.00 mm, the examiner was required to select the 2 measurements closest to the rules of the algorithm. 4600 sites were available for analysis. 3992 sites (86.8%) required 2 recordings, 564 sites (12.3%) required 3 recordings and 44 sites (1%) required 4 recordings. Correlation coefficients for PCD1 and PCD2 and SPCD1 and SPCD2 were 0.83 and 0.96, respectively (p=0.00). Site-specific variances were calculated for PCD1 and PCD2 and SPCD1 and SPCD2. The mean of the PCD1/PCD2 site-specific variances (A) was 0.41 mm2 (range 0.00 mm2 to 33.62 mm2), whilst the mean of the SPCD1/SPCD2 variances (B) was 0.1 mm2 (range 0.00 mm2 to 2.0 mm2): the respective medians were 0.08 mm2 and 0.02 mm2. The study demonstrated high intra-examiner PCD agreement. The option-4 algorithm produced a reduction of 75.6% in the mean site-specific variance of PCD1/PCD2 (Y) (Y=[(A-B)/A]X 100) and a 75% reduction in the median site-specific variance of PCD1/PCD2.

Adult↗
PubMed1999

Role of p16/MTS1, cyclin D1 and RB in primary oral cancer and oral cancer cell lines.

One of the most important components of G1 checkpoint is the retinoblastoma protein (pRB110). The activity of pRB is regulated by its phosphorylation, which is mediated by genes such as cyclin D1 and p16/MTS1. All three genes have been shown to be commonly altered in human malignancies. We have screened a panel of 26 oral squamous cell carcinomas (OSCC), nine premalignant and three normal oral tissue samples as well as eight established OSCC cell lines for mutations in the p16/MTS1 gene. The expression of p16/MTS1, cyclin D1 and pRB110 was also studied in the same panel. We have found p16/MTS1 gene alterations in 5/26 (19%) primary tumours and 6/8 (75%) cell lines. Two primary tumours and five OSCC cell lines had p16/MTS1 point mutations and another three primary and one OSCC cell line contained partial gene deletions. Six of seven p16/MTS1 point mutations resulted in termination codons and the remaining mutation caused a frameshift. Western blot analysis showed absence of p16/MTS1 expression in 18/26 (69%) OSCC, 7/9 (78%) premalignant lesions and 8/8 cell lines. One cell line, H314, contained a frameshift mutation possibly resulting in a truncated p16/MTS1 protein. pRB was detected in 14/25 (56%) of OSCC but only 11/14 (78%) of these contained all or some hypophosphorylated (active) pRB. In premalignant samples, 6/8 (75%) displayed pRB, and all three normal samples and eight cell lines analysed contained RB protein. p16/MTS1 protein was undetectable in 10/11 (91%) OSCCs with positive pRB. Overexpression of cyclin D1 was observed in 9/22 (41%) OSCC, 3/9 (33%) premalignant and 8/8 (100%) of OSCC cell lines. Our data suggest p16/MTS1 mutations and loss of expression to be very common in oral cancer cell lines and less frequent in primary OSCC tumours. A different pattern of p16/MTS1 mutations was observed in OSCC compared to other cancers with all the detected p16/MTS1 mutations resulting in premature termination codons or a frameshift. The RB protein was expressed in about half (44%) of OSCCs and its expression inversely correlated with p16/MTS1 expression. In conclusion, we show that abnormalities of the RB pathway are a common mechanism of oral carcinogenesis.

Carcinoma, Squamous Cell↗
PubMed1999

Treatment of upper aerodigestive tract cancers in England and its effect on survival.

The evidence base for head and neck cancers is low with relatively few randomized controlled trials of the two main treatments, surgery and radiotherapy. The aim of the study was to investigate the patterns of surgery and radiotherapy treatment for head and neck cancers in three large areas of England and to investigate their effects on survival. This was a retrospective study of 13510 cases of head and neck cancers (ICD10: C00-C14, C30-C32) diagnosed and treated from 1984 to 1992 in England. We undertook multivariate analyses of survival using a step-wise Cox proportional hazard model and Kaplan-Meier analysis. There were regional variations in the treatments given to patients. Four in ten patients did not receive currently recommended treatments. In multivariate analyses treatment content and timing had an independent effect on survival. Better survival was associated with surgery for mouth cancers, radiotherapy for laryngeal cancers and combined treatment for pharyngeal cancers independent of tumour and demographic factors. Further research is needed to investigate the findings of this study through large randomized controlled trials and multi-centre audits.

Adult↗
PubMed1999

The upregulation of lysyl oxidase in oral submucous fibrosis and squamous cell carcinoma.

Lysyl oxidase (LO) takes part in the initial steps of converting soluble monomers of collagen and elastin into insoluble fibres in the extracellular matrix. We have studied the immunolocalization of LO as a marker of fibrogenesis in oral submucous fibrosis (OSF). Oral biopsies from 13 subjects with OSF, 6 with histologically confirmed squamous cell carcinoma (SCC) arising in OSF and 10 SCC nonrelated to OSF, were examined. Strong positive staining was observed in 7/13 OSF samples in the cytoplasmic processes of fibroblasts and extracellularly in the upper third of the lamina propria. Furthermore, LO was found to co-localize in the areas stained strongly for collagen and elastin by histochemical stains. Examination of SCC tissues showed localization of LO adjacent to invading epithelial islands as evidence of a stromal reaction both in carcinomas arising from OSF and in SCC from non-OSF cases. These findings suggest that upregulation of LO may be an important factor in the pathogenesis of OSF and in the early stromal reaction of oral cancer.

Carcinoma, Squamous Cell↗
PubMed1999

Dentists and oral cancer prevention in the UK: opinions, attitudes and practices to screening for mucosal lesions and to counselling patients on tobacco and alcohol use: baseline data from 1991.

OBJECTIVE: To investigate the opinions, attitudes and practices towards oral cancer prevention among UK dentists as a baseline from which to measure the need for continuing education efforts in this area. DESIGN AND METHOD: Postal questionnaire survey carried out in August 1991. A questionnaire with 13 test items was piloted at continuing education courses then distributed to all subscribers of the British Dental Journal with a postage paid return envelope. The aspects inquired into were recent attempts by dentists at updating their knowledge on oral cancer, their practical approaches to screening for oral mucosal diseases and follow-up actions after oral screening, their questions to patients regarding the major risk factors for oral cancer, their efforts towards behavioural counselling for patients and any constraints felt or experienced in this regard. RESULTS: The questionnaire was circulated to 15,836 dentists. The response rate of 16% was poor but due to the many dentists circulated, 2519 responses were available for analysis. This large sample, though presumptively biased towards those interested in professional matters, showed an encouraging 84% claiming to perform screening of the oral mucosa routinely. Among these, 74% reported referral of screen detected cases to a hospital for further attention and only 4% would adopt a wait and see policy. Disturbingly, half of the respondents did not enquire about risk habits related to oral cancer and, among the other half who claimed to make such enquiries, only 30% routinely provided brief health education advice concerning these. Seventy-one percent agreed that giving advice against tobacco use is desirable but major constraints were identified, notably a lack of training, and frustration regarding patient compliance. There was even greater reluctance on the part of the respondents to enquire into the alcohol use of their patients and to provide advice on alcohol moderation. CONCLUSIONS: Most of this large but unrepresentative sample of UK dentists were carrying out screening of the oral mucosa as a part of their prevention activities in 1991. However, the survey indicated a considerable need for improvement in the manner and extent of provision of health advice in respect of the major risk factors for oral cancer: such a substantial need amongst the presumptively better motivated implies that the need amongst the practitioner population at large is even greater.

Alcohol Drinking↗