[Preliminary study on the relationship between different blood glucose levels and periodontitis in patients with diabetes mellitus type 2]

Objective: To determine the correlation between the diabetes mellitus control and periodontitis. Methods: This study was a cross-sectional survey using stratified system sampling model design. The target population was the patients with diabetes investigated from May to July 2018 in Huangpu District of Shanghai. In the present study, severe periodontitis was defined as at least at two sites in different quadrants with probing depth (PD)≥6 mm and clinical attachment loss (CAL)≥ 5 mm. Edentulous induced by periodontitis were also classified as severe periodontitis and the others were classified as non-severe periodontitis subjects. Diabetes control levels were divided into the following three groups: poorly controlled group [glycated hemoglobin (HbA1c)>7.5% and fasting blood glucose (FPG)>7.0 mmol/L], well controlled group (6.5%≤HbA1c≤7.5％ or 6.1 mmol/L≤FPG≤7.0 mmol/L) and ideally controlled group (HbA1c<6.5% and FPG<6.1 mmol/L). SPSS 25.0 was used for statistical analysis. Chi square test was used for demographic data and frequency distribution, α=0.05, two-sided test. Ordinal regression model was used for PD and diabetes control status to balance confounding factors (including age, gender, education and smoking status). After matching the propensity scores between severe periodontitis group and non-severe periodontitis group, logistic regression analysis was used to analyze the level of diabetes control and periodontitis. Results: A total of 5 220 adults over the age of 18 with a medical history of diabetes participated in the survey, of which 3 064 subjects with diabetes mellitus type 2 (T2DM) who were given both oral and laboratory examinations and were included in this study. Statistics showed that the prevalence of moderate and severe periodontitis was 10.57% (324/3 064). In the severe periodontitis group, 79.01% (256/324) of the subjects were over 65 years old, 55.56% (180/324) were male, 58.33% (189/324) had lower education level than high school level, and 21.91% (71/324) were smokers, which were significantly higher than those in the non-severe periodontitis group (P<0.01). In different T2DM status groups, the percentage of severe periodontitis increased with the aggravation of T2DM status. In severe periodontitis group, the proportion of patients with poor glycemic control was higher. T2DM patients with poor glycemic control accounted for 68.52% (222/324) in severe periodontitis group, which was significantly higher than the proportion of non-severe periodontitis group of 60.99% (1 671/2 740) (P<0.05). The regression coefficient of PD was 0.191, and PD had a significant negative effect on the level of blood glucose (P<0.01). There was a significant positive correlation between diabetes glycemic control and severe periodontitis (OR=2.800, P<0.05). Conclusions: In Huangpu District of Shanghai, among T2DM patients, the age of severe periodontitis group was higher than that of non-severe periodontitis group, most of them were male, with lower education level and higher proportion of smoking. The severity of diabetes was related to periodontitis and the proportion of severe periodontitis was higher in patients with poor glycemic control.

Characteristics of teenagers who use dental floss

OBJECTIVE

To describe the use of dental floss by teenagers and study associations between flossing and approximal caries experience, oral health behaviours, gender, parental education and national background.

METHODS

The study included 2156 14-year-old teenagers. Data were collected in conjunction with routine dental examinations. Teenagers answered a questionnaire about frequency of and reasons for flossing, oral health behaviours and family characteristics. Information about approximal enamel (D₁₋₂Sa) and dentine caries experience (D₃MFSa) was collected from dental records. Data were cross-tabulated and tested with Chi-Square statistics and ANOVA, and analysed using multivariable logistic regression. The data was baseline data in a longitudinal study exploring effects of dental floss. The study was performed as part of the quality assurance system required by law in the dental services and did not require ethical approval.

RESULTS

Half of the teenagers (54%) used dental floss. Among teenagers who flossed, 15% reported doing so daily. Recommendation from dental personnel was the most important reason for using dental floss. Proportionately more girls and teenagers whose parents had high educational achievement reported flossing. Teenagers who flossed more often had more favourable oral health behaviours than other teenagers but more often had approximal enamel caries (D₁₋₂Sa) and approximal dentine caries experience (D₃MFSa) than other teenagers (p⟨0.05).

CONCLUSION

Use of dental floss was not a daily behaviour in most teenagers. Flossing was associated with having approximal caries lesions, indicating that teenagers having signs of approximal caries had been recommended to use dental floss.

Do enamel and dentine caries at 5 years of age predict caries development in newly erupted teeth? A prospective longitudinal study

Objective: To explore caries development in children from 5 to 12 years of age, and to study whether enamel caries and dentine caries at 5 years of age could predict caries prevalence at 12 years of age, controlled for child characteristics.Methods: The study included 3282 children examined at 5 and 12 years of age. Data were collected by clinical examination and questionnaire. Enamel and dentine caries were registered at surface level. Data were tested by t-test and analysed by bi- and multivariate logistic regression. The study was ethically approved.Results: In 5-year-olds, 15% of the children had dentine caries experience and 21% had enamel caries. In 12-year-olds, 32% had dentine caries experience and 47% had enamel caries. Children with dentine caries experience at 5 years of age had at 12 years of age developed more surfaces with enamel caries (mean 2.8, SD 4.2) and dentine caries experience (mean 1.8, SD 2.5) than other children (p < .05). Dentine caries experience at 12 years of age was associated with having only enamel caries (OR 1.6, CI 1.2-2.0) and dentine caries experience (OR 3.2, CI 2.6-3.9) at 5 years of age. Family status and parental education were related to caries development.Conclusion: Children with caries in primary teeth continued to be caries risk children during the mixed dentition period. In addition to dentine caries experience, enamel caries in primary teeth was a predictor for caries development in young permanent teeth and may be used to improve the caries risk assessment.

Fissure sealants or fluoride varnish? Routines and attitudes among dental health personnel in Norway

PURPOSE

To investigate routines and attitudes among dentists and dental hygienists concerning use of fissure sealants and fluoride varnish for non-operative management of occlusal caries.

METHODS

All dentists and dental hygienists working in child dental care in three counties in Norway were invited to answer a questionnaire on routines for use of fissure sealants and fluoride varnish. Nine statements regarding attitudes towards use of sealants were scored using a five-point Likert scale. Multivariable logistic regression analyses were performed to assess indicators associated with reported routines for use of sealants and varnish. The study was approved by the Norwegian Centre for Research Data.

RESULTS

In total 142 of 189 (75%) dentists and dental hygienists answered the questionnaire. The majority of the respondents, n = 83 (59%), reported to prefer fissure sealants while fluoride varnish was preferred by 57 (41%) of the respondents. Frequent use of fissure sealants was reported by 58 (41%) and frequent use of varnish by 104 (74%) of the respondents. Most (n = 104, 74%), used sealants on specific indications, and 89 (64%) opened fissures only when suspecting dentine caries. Preferred method and routines for occlusal caries management differed between counties (p < 0.05). Almost all clinicians agreed with the statement that sealants are protective against caries, while statements regarding costs, technique sensitivity and children's cooperation revealed some concerns regarding fissure sealing.

CONCLUSIONS

Fissure sealants were the preferred method for occlusal caries management despite reported concerns related to technical aspects and patient cooperation. County-level variation in frequency of sealant use was observed.

Recall intervals and time used for examination and prevention by dentists in child dental care in Denmark, Iceland, Norway and Sweden in 1996 and 2014

OBJECTIVE

The purpose of the present study was to explore intervals between regular dental examination and the time dentists spent for examination and preventive dental care of children in 1996 and 2014.

PARTICIPANTS AND METHODS

In Denmark, Norway and Sweden, random samples of dentists working with children were included, while in Iceland all dentists were mailed questionnaires. Complete information was provided by 1082 of 1834 dentists (64%) in 1996 and 1366 of 2334 dentists (59%) in 2014. Results were assessed using chi-square and analysis of variance with post-hoc tests.

RESULTS

Some trends were consistent in all countries, but considerable differences in routines between the countries persisted during the period. The most used and maximum planned recall intervals were on average 14.8 (sd 4.8) and 18.5 (sd 4.6) months in 2014, respectively 3.1 and 3.5 months longer than in 1996 (p⟨0.05). In 2014 dentists used ample time delivering preventive care to children. Dentists reported spending significantly more time providing preventive care for caries risk children than for other children both in 1996 and 2014. Concurrent with extended intervals, dentists reported spending longer performing routine examinations in three of the four countries in 2014 than in 1996.

CONCLUSIONS

This study of trends in dental care delivered by dentists during recent decades showed moves towards extended recall intervals and preventive care individualized according to caries risk. In addition, extending intervals could necessitate more time for a routine dental examination.

Caries-preventive self-care for children. Consistent oral health messages to the public?

BACKGROUND

Recommendations regarding caries-preventive self-care for children are provided by several health authorities.

OBJECTIVE

To investigate recommendations given to the public regarding children's caries-preventive self-care by Norwegian dentists, dental hygienists, dental nurses and public health nurses.

METHODS

Questionnaires were sent by e-mail and answered by 808 of 1132 persons who provide oral preventive promotion to children in dental services and health centres. The preventive advice was obtained through questions about the preferred preventive methods, fluoride recommendations and sources of knowledge on which the personnel based the advice about caries prevention in children. The responses were analysed using logistic regression.

RESULTS

The majority (59-71%) in all professions judged oral hygiene education to be the most important caries-preventive method. Most personnel (84-98%) recommended all children to use fluoride toothpaste, and half of all personnel (53%) recommended fluoride lozenges for 50% or more of children. Multivariate analysis showed that dental nurses recommended lozenges to more children than dentists (OR 2.5, 95% CI 1.7-3.7), while health nurses recommended lozenges to fewer children than dentists (OR 0.5, 95% CI 0.3-0.8). The most important source of knowledge reported by dental personnel was professional education, while health nurses relied on information from dental personnel.

CONCLUSIONS

Health professions' recommendations regarding caries-preventive self-care for children were mainly similar, although variation existed both between and within professions. Collaboration between professions and awareness of the evidence base for preventive oral care may improve the consistency of information given by health professionals to the public.

Dentists' views on the effects of changing economic conditions on dental services provided for children and adolescents in Iceland

In 2008, Iceland experienced a major financial crisis, with serious effects on the economy of the country and its inhabitants.

OBJECTIVE

To describe the opinions of dentists in Iceland regarding the influence of economic changes on the demand for dental health services for children and adolescents, aged 0-18 years, and also to describe the preventive dental care the dentists reported providing for children and adolescents.

BASIC RESEARCH DESIGN AND PARTICIPANTS

Questionnaires were sent by electronic mail to all dentists in Iceland in January 2013. Of the dentists working with children, 161 (62%) returned the questionnaire.

RESULTS

Important findings were that 119 (74%) of the respondents reported increased caries experience in children and adolescents and 150 (93%) reported that decreased reimbursement for dental treatment of children in recent years had affected the dental health of most or some children and adolescents. Most dentists reported reduced parental demand for most aspects of caries prevention and treatment, apart from treatment for acute dental pain. The mean interval between dental visits was reported to be 9.4 months (sd 2.8) and the mean maximal interval 12.1 months (sd 2.8). The mean proportion of working time allocated for caries preventive services was reported to be 31% (sd 21).

CONCLUSIONS

The results indicate a contrast between increased need for children's dental care perceived by the dentists and reduced demand for care from the parents. This may be a temporary phenomenon, as the economic crisis passes, reimbursement for dental care may increase.

Caries increment and prediction from 12 to 18 years of age: A follow-up study

AIM

This was to determine the increment of caries from 12 to 18 years of age and to explore the possibility of predicting caries increment in this period based on the caries experience at age 12 years.

STUDY DESIGN

Prospective longitudinal survey.

METHODS

A sample of 12-year-old children (n =159) were examined in 1993 and 70% of them re-examined at 18 years of age. Bitewing radiographs were taken and a diagnostic system using five caries grades (D(1) to D D(5)) was used at both ages. Children at risk were defined as those who developed manifest caries lesions (D(3-5)FS) on approximal surfaces during the follow-up period. Possible predictors were analysed by calculation of sensitivity, specificity, efficiency of the test, proportion that tested positive and actual proportion of the population at risk.

RESULTS

The mean caries increment (D(1-5)MFS) from 12 to 18 years of age was 4.2 (SD +/- 9.1). The percentage of caries-free adolescents at 12 and 18 years of age was 10% and 1% respectively; 25% had either a reversal or no increment in caries experience while the D(1-5)MFS increased in 65% of the adolescents. Of the increment of manifest lesions (D(3-5)FS), 18% were located in incisors/canines, 40% in premolars, 26% in first molars and 16% in second molars. Premolars had the largest proportion of the approximal surfaces with manifest caries increment. The best predictors of children at risk of approximal caries increment (D(3-5)FS) were caries experience (D(1-5)FS) on the approximal surfaces of premolars and second molars at the age of 12 years. The individuals that developed four or more manifest lesions on approximal surfaces between 12 and 18 years were the easiest to predict (sensitivity + specificity = 175%).

CONCLUSIONS

There was a considerable increment of manifest caries lesions from 12 to 18 years of age in all tooth groups. The best predictors for increment of manifest caries on approximal surfaces during the age period were approximal caries in premolars and second molars at the age of 12 years.

Screening and identification of peritoneal metastasis-related genes of gastric adenocarcinoma using a cDNA microarray

With the aim of identifying peritoneal metastasis-related genes in gastric cancer, we performed a broad analysis of differential gene expression between the parental cell line GC9811 and its highly metastatic peritoneal counterpart, cell line GC9811-P. Two fluorescent cDNA probes, labeled with Cy3 and Cy5 dyes, were prepared from GC9811 and GC9811-P mRNA samples by the reverse transcription method. The two color probes were then mixed and hybridized to a cDNA chip constructed with double-dots from 11,901 human genes; this was scanned at two wavelengths. The experiment was repeated twice. In GC9811-P cells, 218 genes were upregulated and 30 genes were downregulated compared with the parental cell lines. Some selected genes were confirmed by RT-PCR and Western blot; we found that S100A4 and CTNNB1 were upregulated and PTEN was downregulated in GC9811-P cells. Identification of these differentially expressed genes could contribute to disclose the molecular mechanisms involved and provide new targets for therapeutic intervention to avoid peritoneal dissemination of gastric adenocarcinoma.

Does oral health matter in people's daily life? Oral health-related quality of life in adults 35-47 years of age in Norway

OBJECTIVE

The aim of this study was to assess the effect of oral health on aspects of daily life measured by the Dental Impact Profile (DIP) in 35- to 47-year-old individuals in Norway, and to study associations between reported effects and demographic variables, subjectively assessed oral health, general health, oral health behaviour and clinical oral health.

MATERIAL AND METHODS

A stratified randomized sample of 249 individuals received a questionnaire regarding demographic questions, dental visits, oral hygiene behaviour, self-rated oral health and general health and satisfaction with oral health. The DIP measured the effects of oral health on daily life. Teeth present and caries experience were registered by clinical examination. Bi- and multivariate analyses and factor analysis were used.

RESULTS

Items most frequently reported to be positively or negatively influenced by oral health were chewing and biting, eating, smiling and laughing, feeling comfortable and appearance. Only 1% reported no effects of oral health. Individuals with fewer than two decayed teeth, individuals who rated their oral health as good or practised good oral health habits reported more positive effects than others on oral quality of life (P ≤ 0.05). When the variables were included in multivariate analysis, none was statistically significant. The subscales of the DIP were somewhat different from the originally suggested subscales.

CONCLUSIONS

This study showed that most adults reported oral health to be important for masticatory functions and confirmed that oral health also had impacts on other aspects of life.

Changes of pituitary and penile structure in male adult rats following castration and high-fat diet

AIM

To investigate the influence of low androgen levels and high-fat diet on the structure of pituitary and penis in male rats.

METHODS

Ten-week-old adult male Sprague-Dawley rats were randomly divided into 2 groups, one fed a high-fat diet the other fed a normal diet; each group consisted of 3 subgroups: controls, castrated rats (with low androgen), and castrated rats given undecanoate replenishment. After 11 weeks, the structure of pituitary and penis were observed under light microscopy. Immunohistochemistry was used to assess the expression of FSH in pituitary and cyclooxygenase-2 (COX-2) in corpora cavernosa penis.

RESULTS

The structures of pituitary and penis in castrated rats were injured, and were more damaged in castration together with high-fat diet. Immunohistochemistry showed FSH expression in castrated rats pituitary while castrated rats on a high-fat diet had less positive staining than those on a normal diet. Vascular structure of corpora cavernosa penis, showed a strongly positive COX-2 expression in high-fat diet rats.

CONCLUSIONS

Castration and high-fat diet could induce structural damages of pituitary and penis in male rats. Replacement with testosterone could partially restore the impaired structure. The positive expression of COX-2 implied inflammatory pathway existence on vascular structure of penis in high-fat diet and low-androgen male rats.

Reliability of two clinical scoring systems for dental erosive wear

The aim of the study was to evaluate and compare two dental erosive wear scoring systems, the Visual Erosion Dental Examination (VEDE) and Basic Erosive Wear Examination (BEWE). Seventy-four tooth surfaces (photographs) and 562 surfaces (in participants) were scored by 5 (photographs) or 3 (in participants) clinicians using both scoring systems. The surfaces in the photographs were scored twice. The level of agreement was measured by weighted kappa (kappa(w)). Inter- and intraexaminer agreement showed small variations between the examiners for both systems when scoring the photographs. Slightly higher mean kappa(w) values were found for VEDE (kappa(w) = 0.77) compared with BEWE (kappa(w) = 0.69). When scoring the surfaces in the clinical examination the mean kappa(w) values for the two systems were equal (kappa(w) = 0.73). Interexaminer agreement using VEDE was calculated to see how differentiation between enamel and dentine lesions influenced the variability. The highest agreement was found for score 0 (sound, 86%) and score 3 (exposure of dentine, 67%), while the smallest agreement was shown for score 1 (initial loss of enamel, 30%) and score 2 (pronounced loss of enamel, 57%). The reliability of the two scoring systems proved acceptable for scoring the severity of dental erosive wear and for recording such lesions in prevalence studies. The greatest difficulties were found when scoring enamel lesions, especially initial lesions, while good agreement was observed when examining sound surfaces (score 0) and dentine lesions (score 3).

Preventive care and recall intervals. Targeting of services in child dental care in Norway

Skewed caries distribution has made interesting the use of a high risk strategy in child dental services.

OBJECTIVE

The purpose of this study was to describe the preventive dental care given and the recall intervals used for children and adolescents in a low caries risk population, and to study how the time spent for preventive care and the length of intervals were associated with characteristics of the children and factors related to care delivery.

MATERIAL AND METHODS

Time spent for and type of preventive care, recall intervals, oral health and health behaviour of children and adolescents three to 18 years of age (n = 576) and the preventive services delivered were registered at routine dental examinations in the public dental services.

RESULTS

The time used for preventive dental care was on average 22% of the total time used in a course of treatment (7.3 of 33.4 minutes). Less than 15% of the variation in time spent for prevention was explained by oral health, oral health behaviours and other characteristics of the children and the service delivery. The mean (SD) recall intervals were 15.4 (4.6) months and 55% of the children were given intervals equal to or longer than 18 months. Approximately 30% of the variation in the length of the recall intervals was explained by characteristics of the child and the service delivery.

CONCLUSIONS

The time used for preventive dental care of children in a low risk population was standardized, while the recall intervals to a certain extent were individualized according to dental health and dental health behaviour.

Chromosome 15q11-13 duplication syndrome brain reveals epigenetic alterations in gene expression not predicted from copy number

BACKGROUND

Chromosome 15q11-13 contains a cluster of imprinted genes essential for normal mammalian neurodevelopment. Deficiencies in paternal or maternal 15q11-13 alleles result in Prader-Willi or Angelman syndromes, respectively, and maternal duplications lead to a distinct condition that often includes autism. Overexpression of maternally expressed imprinted genes is predicted to cause 15q11-13-associated autism, but a link between gene dosage and expression has not been experimentally determined in brain.

METHODS

Postmortem brain tissue was obtained from a male with 15q11-13 hexasomy and a female with 15q11-13 tetrasomy. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure 10 15q11-13 transcripts in maternal 15q11-13 duplication, Prader-Willi syndrome, and control brain samples. Southern blot, bisulfite sequencing and fluorescence in situ hybridisation were used to investigate epigenetic mechanisms of gene regulation.

RESULTS

Gene expression and DNA methylation correlated with parental gene dosage in the male 15q11-13 duplication sample with severe cognitive impairment and seizures. Strikingly, the female with autism and milder Prader-Willi-like characteristics demonstrated unexpected deficiencies in the paternally expressed transcripts SNRPN, NDN, HBII85, and HBII52 and unchanged levels of maternally expressed UBE3A compared to controls. Paternal expression abnormalities in the female duplication sample were consistent with elevated DNA methylation of the 15q11-13 imprinting control region (ICR). Expression of non-imprinted 15q11-13 GABA receptor subunit genes was significantly reduced specifically in the female 15q11-13 duplication brain without detectable GABRB3 methylation differences.

CONCLUSION

Our findings suggest that genetic copy number changes combined with additional genetic or environmental influences on epigenetic mechanisms impact outcome and clinical heterogeneity of 15q11-13 duplication syndromes.

Dental caries and associated factors in 12-year-old schoolchildren in Thiruvananthapuram, Kerala, India

OBJECTIVES

The aims of the present study were to describe the dental health status of 12-year-old schoolchildren in Thiruvananthapuram, Kerala, India, and to identify sociodemographic factors, oral health behaviours, attitudes and knowledge related to dental caries experience.

METHODS

The study took the form of a cross-sectional survey of 838 children in upper primary schools. A two-stage cluster sampling technique was used. Dental caries was measured using World Health Organization criteria. Sociodemographic factors, oral health behaviours, attitudes and knowledge were assessed by a self-administered questionnaire.

RESULTS

The prevalence of dental caries in the permanent dentition was 27%. The mean number of decayed, missing and filled teeth was 0.5 (SD=0.9). The decayed component (D) constituted 91% of the total number of decayed, missing and filled teeth (DMFT). Multiple logistic regression analysis showed that children had a higher risk of having dental caries if they lived in urban area [OR=1.5, 95% confidence interval (CI)=1.1-2.1], had visited a dentist (OR=1.6, 95% CI=1.2-2.2), did not use a toothbrush (OR=1.9, 95% CI=1.2-2.9), consumed sweets (OR=1.4, 95% CI=1.0-1.9) or performed poorly in school (OR=1.7, 95% CI=1.0-2.3).

CONCLUSIONS

The prevalence of caries in this sample of 12-year-old schoolchildren was low compared to that in other developing countries. The present study indicated that urban living conditions were associated with more dental caries. Since urbanization is rapid in India, oral health promotion at the present time would be valuable to prevent increased caries prevalence.

Supernumerary tricentric derivative chromosome 15 in two boys with intractable epilepsy: another mechanism for partial hexasomy

Rearrangements of chromosome 15q, including isodicentric 15 chromosomes and interstitial duplications and triplications, have been previously reported in association with autism spectrum disorders. We have identified two boys with exceptionally large der(15) chromosomes that are tricentric and contain four copies of the proximal long arm, including the Prader Willi/Angelman critical region, and leading to hexasomy of the involved segment. Biallelic inheritance of maternal alleles and methylation analysis indicate that the markers are maternally derived. Clinical assessment of the boys indicated severe cognitive impairment associated with marked delays in gross and fine motor skills. Social and language deficits were present in both, although the severity of the mental retardation precluded diagnosis of autism (both were considered to have pervasive developmental disorder-not otherwise specified). Neurologic manifestations included infantile spasms evolving into intractable early-onset myoclonic seizures, psychomotor regression, and profound diffuse hypotonia. These patients represent the most severe end of the spectrum of phenotypes associated with segmental aneuploidy for chromosome 15q11-q13.

Effect of macrophage-derived apolipoprotein E on established atherosclerosis in apolipoprotein E-deficient mice

Apolipoprotein E-deficient (apoE(-/-)) mice have hyperlipidemia and develop spontaneous atherosclerosis in a time-dependent manner. Although macrophage-derived apoE has been shown to prevent the development of atherosclerosis in apoE(-/-) mice, whether it would induce regression of established atherosclerosis is unknown. To determine this, 8-week-old apoE(-/-) mice were transplanted with apoE(+/+) bone marrow. Four weeks after transplantation, when plasma cholesterol levels had reached normal levels, a group of mice (n=12) were killed and their aortic lesions were measured and used as a baseline to judge regression. Twelve and 20 weeks after transplantation, aortic lesion areas of the mice were 9340+/-2184 micrometer(2) (mean+/-SEM, n=8) and 12 211+/-1433 micrometer(2) (n=9), respectively, values not significantly different from the lesion areas of the baseline mice (12 347+/-2487 micrometer(2); n=12, P>0.05). In contrast, apoE(-/-) mice reconstituted with apoE(-/-) bone marrow developed severe atherosclerotic lesions (453 036+/-29 767 micrometer(2), n=7) 20 weeks after transplantation. These data suggest that macrophage-derived apoE was insufficient to induce significant regression of established atherosclerotic lesions in apoE(-/-) mice, although it was sufficient to eliminate hypercholesterolemia and prevent progression of aortic lesions.

Is amalgam in child dental care on its way out? Restorative materials used in children and adolescents in 1978 and 1995 in Norway

OBJECTIVE

Improvements in dental health in children and adolescents and development of dental materials influence the selection of restorative materials. The purpose of this study was to obtain information on the amount and type of restorative materials used in children and adolescents in Norway in 1995 and compare this with the materials placed in 1978. DESIGN DATA: on numbers of restored surfaces and the use of amalgam and other restorative materials were collected from the dental records of 7,278 children aged 5, 9, 12, 15 and 18 years in 1995. Data from 1978 on 9,224 children were collected from the reports of the public dental services.

RESULTS

From 1978 to 1995, the number of permanent surfaces restored was reduced by 69, 68, 64 and 52% for 9-, 12-, 15- and 18-year-old children respectively, and the number of primary surfaces restored declined by 64 and 59% in 5- and 9-year-old children. The proportion of restored surfaces that were filled with amalgam was reduced in all age groups and in both primary and permanent teeth. In 1995 most of the surfaces restored were filled with glass ionomer. The number of surfaces restored with amalgam decreased in all age groups. The reduction varied from 73% in the oldest age group to 97% among 5-year-old children.

CONCLUSIONS

The study shows that the use of amalgam has decreased dramatically in children and adolescents and that with the present low caries rates the amount of amalgam inserted is small.

Determinants of atherosclerosis susceptibility in the C3H and C57BL/6 mouse model: evidence for involvement of endothelial cells but not blood cells or cholesterol metabolism

Lipids, monocytes, and arterial wall cells are primary components involved in atherogenesis. Using the inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H), which have been extensively studied as models of the genetic control of diet-induced atherosclerosis, we examined which of these components determine genetic susceptibility. To test whether dietary responsiveness is involved, a congenic strain of C3H carrying an apoE-null allele (apoE(-/-)) was constructed. Although C3H.apoE(-/-) mice had higher plasma cholesterol levels, they developed much smaller lesions than their B6.apoE(-/-) counterpart on either chow or Western diets. Reciprocal bone marrow transplantation between the strains, with congenics carrying the same H-2 haplotype, was performed to examine the role of monocytes. The atherosclerosis susceptibility was not altered in the recipient mice, indicating that variations in monocyte function were not involved. Endothelial cells isolated from the aorta of B6 mice exhibited a dramatic induction of monocyte chemotactic protein-1, macrophage colony-stimulating factor, vascular cell adhesion molecule-1, and heme oxygenase-1 in response to minimally modified LDL, whereas endothelial cells from C3H mice showed little or no induction. In a set of recombinant inbred strains derived from the B6 and C3H parental strains, endothelial responses to minimally modified LDL cosegregated with aortic lesion size. These data provide strong evidence that endothelial cells, but not monocytes or plasma lipid levels, account for the difference in susceptibility to atherosclerosis between the 2 mouse strains.

Correlation of immunohistochemical staining and mutations of p53 in human hepatocellular carcinoma

Mutations of the p53 tumor suppressor gene are common in hepatocellular carcinomas (HCCs). Detection of mutations by sequencing provides more information than immunohistochemical staining, but the equipment needed and the time required make it less practical for use in large-scale studies or in studies in developing countries. The degree of correlation between results obtained with these two methods has been studied in various tumors but has not been well-established in human HCCs. Paraffin sections of HCCs of 28 patients from Qidong, China were immunohistochemically stained using monoclonal antibody to p53. In addition, exons 5-8 of the p53 gene were sequenced in these HCCs. Of the 28 HCCs, nine had 0-9% of nuclei stained for p53, and 19 had 50-95% stained. Mutations in p53 exons 5-8 were found in 17/28 (61%) HCCs, including 15 at codon 249 (exon 7), one at codon 198 (exon 6), and one at codon 175 (exon 5). Among these 17 cases with p53 mutations, 16 cases (94%) had 50-95% of nuclei stained. Among 11 HCCs with no mutations by sequencing, 8 were also negative by immunohistochemistry (0-9% of nuclei stained) (73%) (the five HCCs with no staining whatsoever all had wild-type p53). Immunohistochemical staining to detect p53 mutations in human HCCs detected most mutations that were detected by sequencing (94% sensitivity, 73% specificity), and this method is therefore suitable when sequencing cannot be performed.

Government policies on fluoride utilization in the Nordic countries

In most but not all the Nordic countries, the National Boards of Health have issued guidelines governing the utilization of fluoride. The purpose of this paper is to outline the process of policy formation, describe the current fluoride guidelines in the Nordic countries, and discuss compliance with and appropriateness of the guidelines. The fluoride guidelines summarize current knowledge and make recommendations on choice of fluoride preparations (supplements, toothpaste, and varnish) and doses. Fluoride policies in the Nordic countries in the late 1990s state that use of fluoride toothpaste twice a day is the preferred and sufficient source of fluoride for the majority of the population. The policies of the Nordic countries are similar, but there are differences, some of them self-explanatory others not so obvious. In the case of supplements, for example, there are differences in the recommended dosage schedules. In the case of toothpaste, it is unclear what concentrations of fluoride are recommended both for children and for adults. Starting time for the use of fluoride, whether toothpaste or supplements, varies between countries. The clinicians' compliance with fluoride guidelines has not been systematically evaluated. Comparing the advice and treatments offered by dentists in the Nordic countries with current guidelines suggests that national policies influence the practice of clinicians. For government policy to be appropriate, it is imperative that the guidelines are based on sound scientific evidence. It is thus concluded that if nonevidence-based elements are included in national guidelines, this should be clearly stated to prevent confusion and enhance compliance from professionals and the public.

Fluoride supplements and caries in a non-fluoridated child population

In Norway, there is no water fluoridation and little naturally occurring fluoride in drinking water. Fluoride toothpaste is used by 95% of the population and there is a long tradition of use of fluoride supplements. The purpose of this study was to analyse whether children who used fluoride toothpaste regularly and complied with the recommendations for use of fluoride supplements had less caries than other children at the age of 8 years. Most fluoride supplements sold in Norway are lozenge-type tablets, which allow for extended enamel exposure to fluoride. All children (n = 551) born in 1988 living in a suburban community in Norway were invited to participate. In those who participated (n = 470), caries was registered clinically and radiographically and parents provided data on use of supplements. Thirty-eight percent of the children had used fluoride supplements regularly during the period 0.5 to 4.0 years of age and 66% used supplements regularly at the age of 6 to 8 years. Multivariate analyses showed that the children complying with the recommendations for use of fluoride supplements during the period 0.5 to 4.0 years of age had lower caries experience (dmfs) and fewer decayed surfaces (ds) in primary teeth than other children. No significant associations were found between supplement use in childhood and caries prevalence (DMFS) or number of decayed surfaces (DS) in permanent teeth at the age of 8 years. Supplement use from 6 to 8 years of age was not associated with caries occurrence either in primary or in permanent teeth. Both mother's education and the quality of dental hygiene were inversely associated with caries occurrence.

Caries-preventive methods used for children and adolescents in Denmark, Iceland, Norway and Sweden

Denmark, Iceland, Norway, and Sweden have all had a similar decline in dental caries during the last 20 years, although the decline has come later in Iceland. The purpose of this study was to compare the caries-preventive methods used for children and adolescents in these four countries. Questionnaires were sent to random samples of dentists, dental hygienists, and dental nurses working with children during 1995 and 1996. The results showed that the use of preventive methods was generally consistent between the countries. Nevertheless there were differences between the countries concerning the choice of preventive strategy for risk patients and also in how prevention was implemented. Danish dental care providers chose oral hygiene education as the priority, which they put into practice. Apart from fluoride varnish for some patients, most of them did not use or recommend fluoride except fluoride toothpaste. The Norwegian and Icelandic dental care providers chose both oral hygiene education and the use of fluoride as priorities, while most Swedish dental care providers preferred to provide dietary advice and oral hygiene education, and additional fluoride for risk patients. The differences could not be explained by other variables than nationality, implying that there are differences between the dental cultures in the four countries. The informational basis of decisions on preventive strategies varied between the different dental professionals in each country as well as between the countries, indicating that national professional cultures are being shaped differently. Despite the differences in choice of preventive methods, the dental health of children varies little across the frontiers. This raises the question of the significance of the choice of preventive methods to the decline of dental caries and points towards an urgent need to develop evidence-based preventive strategies.

Clinical judgement as a basis for choice of recall interval in child dental care?

OBJECTIVE

Extending recall intervals can be an important strategy for making children's dental care more efficient. The purpose of this study was to describe the recall intervals that the clinicians decided were appropriate for children and adolescents when they were instructed to extend and individualise the routines based on clinical judgement. In addition, the effect on recall interval of the profession of the clinician (dentist or dental hygienist), the child's age and the need for fillings were studied.

DESIGN

In a four week period in 1995, all dentists and dental hygienists in one county in Norway reported recall intervals for 2,513 children aged 3 to 18 years.

RESULTS

The mean current interval since the previous examination was 17.1 months (SD = 4.7 months) and the mean proposed interval until the next examination was 16.4 months (SD = 4.4 months). Approximately 50% of children were evaluated by the clinicians to be suitable for recall intervals of 20 months or more and 10% were assessed as requiring a new examination within 12 months. The length of the current recall interval, the age of the child, whether or not the child received fillings, and whether the decision-maker was a dentist or a dental hygienist were statistically significantly associated with the length of the proposed recall interval.

CONCLUSIONS

Basing recall intervals on clinical judgement resulted in intervals longer than 12 months for the majority of the children.

Caries preventive services for children and adolescents in Denmark, Iceland, Norway and Sweden: strategies and resource allocation

According to the dental acts of Denmark, Iceland, Norway and Sweden, emphasis is placed on preventive dental care. The purpose of this study was to describe and compare two aspects of the caries preventive services: the strategies and the resource allocation for preventive dental care of children and adolescents in Denmark, Iceland, Norway and Sweden. Questionnaires were sent to samples of dentists and other dental personnel who provided preventive care to children during 1995 and 1996. Comparisons between the countries showed significant differences in recall routines and in implementation of risk-based and population-based preventive strategies. Multivariate analyses showed that the time used for preventive care varied by country and was not associated with the DMFT of the children. More time was allocated for prevention when more operating dental auxiliaries were available at the clinic, when the recall interval was shorter, when the time used for routine examination was longer and when the clinician was an auxiliary rather than a dentist. In conclusion, resource allocation and strategies used for prevention were not consistent between the countries.

Preventive dental care of children and adolescents in the 1990s: Denmark, Iceland, Norway, and Sweden

This article describes the provision of preventive care for children and adolescents in Denmark, Iceland, Norway, and Sweden in the 1990s. It includes information on personnel giving preventive care, administration of the dental care system, strategies and methods used for prevention, and resources allocated for preventive dental care. In all these countries comprehensive and systematic dental care, subsidized or free of charge, has been instituted for children and adolescents. However, comparisons between the countries show significant differences in the organization of the dental care for children, the time used for preventive care, the recall routines, and the implementation of risk-based and population-based preventive strategies. The relative importance of different caries-prevention methods (fluorides, hygiene, and diet) reported by the clinicians varied between Denmark, Iceland, Norway, and Sweden. While variation poses rather than answers questions concerning effectiveness, available data provide evidence of differences in the input of resources. Unless the dental profession addresses the issue of effectiveness of preventive dental care, politicians and administrators in a cost-containment context will easily conclude that least is best.

Risk factors associated with fluorosis in a non-fluoridated population in Norway

In Norway, there is no water fluoridation and little naturally occurring fluoride in drinking water. Fluoride toothpaste is used by 95% of the population and there is a long tradition of fluoride supplement use. The purpose of this study was to record the prevalence and severity of dental fluorosis in 8-year-old children and relate this to systemic fluoride exposure (supplements and toothpaste). All children (n = 551, born 1988) in a municipality in Norway were invited to participate. Dental fluorosis on the buccal surface of the upper permanent incisors was recorded according to the Thylstrup-Fejerskov index (TF). Parents provided data on use of supplements and toothpaste. Complete data were obtained from 383 children. Sixty-seven percent of the children had used fluoride supplements regularly during childhood. At 8 months or earlier, the teeth of 26% of the children, and at age 14 months or earlier the teeth of 82%, were being brushed. Among children who used fluoride supplements regularly, periodically, seldom and not at all, 45%, 21%, 10% and 0%, respectively, had dental fluorosis. The dental fluorosis was mild (TF = 1) in 87% of the cases. Bivariate and multivariate analyses showed that, in addition to use of fluoride supplements, starting toothbrushing at an early age was associated with higher prevalence of dental fluorosis. The child's birth weight and liking for or swallowing of toothpaste did not influence the prevalence of fluorosis. Risk factors for fluorosis were use of toothpaste before the age of 14 months and regular use of fluoride supplements during childhood.

Analysis of transforming growth factor (TGF)-alpha/epidermal growth factor receptor, hepatocyte growth Factor/c-met,TGF-beta receptor type II, and p53 expression in human hepatocellular carcinomas

Experimental data suggest that dysregulation of growth factors and the cognate receptors may play an important role in hepatocarcinogenesis. The objective of the present study was to characterize the expression of two hepatotrophic growth factor/receptor systems [transforming growth factor-alpha/epidermal growth factor receptor (TGF-alpha/EGFR) and hepatocyte growth factor/c-met receptor (HGF/c-met)], both of which are implicated in the development of human liver tumors. In addition, we have analyzed the expression of transforming growth factor-beta receptor type II (TGF-beta-RII) and p53, genes associated with growth inhibition and tumor suppression, respectively. Surgical biopsy specimens from 86 human hepatocellular carcinomas were analyzed. TGF-alpha was overexpressed in 17%, equally expressed in 21%, and down-regulated in 62% of the hepatocellular carcinomas when compared to the surrounding hepatic tissue. No major changes were found with EGFR expression. HGF was over-expressed in 33% and down-regulated in 21% of the tumors. The c-met receptor was overexpressed in 20%, equally expressed in 48%, and down-regulated in 32% of the neoplasms. In contrast, TGF-beta-RII was overexpressed in only 8%, equal in 42%, and down-regulated in 50% of tumors. Nuclear staining of p53, indicative of a mutation(s), was observed in the great majority of the tumors (80%), whereas no nuclear p53 was detected in peritumoral tissues. Interestingly, simultaneous down-regulation of c-met and TGF-beta-RII was observed in 23% of the hepatocellular carcinomas, 85% of which also showed nuclear p53 staining. Taken together, our data suggest that down-regulation of c-met and TGF-beta-RII may, together with p53 mutations, play a significant role in human liver carcinogenesis.

Dental caries and resources spent for dental care among immigrant children and adolescents in Norway

The purpose of this study was to compare dental status and resource requirements in immigrants to Norway, three to 18 years of age, with Norwegians of the same age group. Data on dmft and DMFT, fillings placed and time spent for dental care were registered in the records of 9000 such children in the period 1992-93. Eleven per cent of the children were immigrant children. Immigrant children three to six years of age had fewer sound teeth and more decayed, missing and filled teeth than Norwegian children and the pre-school immigrant children had higher treatment needs. However, the time spent on a pre-school child with an immigrant background was shorter than the time spent on a Norwegian child with the same number of decayed teeth. The differences between immigrants and Norwegians disappeared with higher age. Immigrant children older than six years had dental health and resource requirements similar to those of Norwegian adolescents.

Individualizing recall intervals in child dental care

Individualizing and extending recall intervals for children have been recommended in Norway to target resources efficiently. Recall intervals were changed for children aged 3-18 years in Drammen from 1991. Clinical time spent by dentists and dental hygienists, dental health status and length of recall intervals were registered from 1990 to 1993. For the child population, the mean recall interval changed from 12.5 to 13.7 months and the annual time spent per child was reduced by 14% from 1990-91 to 1992-93. Adjusted for the decline in number of new decayed teeth, the reduction in time spent was 11%. Children with intervals of 17 to 20 months had fewer new decayed teeth and their care required less personnel time than other children. For children with new decayed teeth, time spent for dental care was not associated with recall interval, while for children without new decayed teeth, longer recall intervals were associated with shorter time for dental care. The variation in number of decayed teeth and time spent for dental care was substantial at all intervals. Individualizing and extending recall intervals to some extent targeted resources at children with more dental disease. However, in the short run, inequality in dental health persisted. Limited extension of recall intervals did not interrupt the long-term trend toward better dental health in the children and substantial resources were saved in the dental services.

Recall intervals, dental hygienists and quality in child dental care

Decline in dental disease and the need to provide dental care efficiently suggest changes in clinical and administrative routines in public dental care provision for children. A field project in Norway demonstrated productivity gains after the introduction of individualized recall intervals and using dental hygienists to conduct recall examinations. The purpose of the present study was to assess changes in the quality of dental health outcome and changes in the quality of the process of dental care provision. Recall intervals were increased from a target of 12 months to 16 and 18 months in two districts. Dental hygienists undertook all recall examinations and referred to dentists those patients who required operative care. Bitewing radiographs were inspected for all 18-yr-olds who were examined in 1989, 1990 and 1991 (n = 956) and for those who were examined before the changes were implemented in 1987 (n = 300). For each child, approximal caries on 24 surfaces was scored according to a 4-point severity scale. Clinical records were examined to determine what treatment had been provided. For each year after the changes were implemented, the quality of health outcome was assessed by comparing the radiographic caries prevalence and the number of sound surfaces with 1987 data. Quality in the process of care provision was indicated by the treatment decisions for approximal caries and by the proportion of uninterpretable surfaces on radiographs for each study year. The mean number of sound surfaces increased over time. A declining proportion of sound surfaces was restored over the study period, and almost all caries lesions extending deep into dentine were restored. Radiographic quality improved during the project period.(ABSTRACT TRUNCATED AT 250 WORDS)

Productivity in dental care for children. Factors influencing the time spent delivering dental care

The cost of dental services is related to their productivity. The purpose of the study was to identify factors influencing productivity, measured as time spent providing dental care per child under care, per year, in public dental clinics. The time was expected to vary with characteristics of the patients, the personnel and the clinics. Time spent by dentists and dental hygienists delivering dental care for children aged three to 18 years was obtained from 137 public dental clinics. The data showed substantial variation in productivity between clinics. Multiple regression analysis revealed that the time spent per child was associated with interval between examinations, proportion of male dentists, ratio of dental assistants to dentists, proportion of child treatment time given by dental hygienists and proportion of all treatment time spent on child patients. These variables explained 43 per cent of the variance in the total time spent by dentists and hygienists and 41 per cent of the variance in dentists' time. Individual dentists and hygienists may reduce the mean time spent per child by extending recall intervals. On an administrative level, dentists' time per child may be reduced by employing more dental assistants or dental hygienists and allowing dentists to treat patient groups other than children. It is concluded that productivity in dental care for children in the public dental services may be influenced in several ways, both by clinical and administrative decisions.

Use of dental hygienists and returns to scale in child dental care in Norway

The purpose of this study was to investigate, in the provision of dental care for children, technically and economically efficient combinations of dentists and dental hygienists and to study returns to scale by analyzing production functions. Data from 137 dental health clinics were analyzed. Output was registered as the number of 3-18-yr-old children to whom the clinic delivered complete dental care. Resource input was registered as hours spent by dentists, dental hygienists and dental assistants to deliver care to the children. The average clinic that employed dental hygienists used one hygienist hour per three dentist hours for child dental care. It would save dentist time, but not costs, to extent the use of hygienists. Increased use of dental hygienists might be economically efficient if the work distribution between the personnel groups were changed, for example, by delegating more examinations and preventive care to hygienists. There were technical opportunities for further substitution of dental hygienists for dentists both by introducing dental hygienists in the clinics that only used dentists in child dental care and by extending use of hygienists in clinics that already employed hygienists. This study found no productivity gain from centralizing treatment of children in large dental clinics.

Variation in clinical time spent by dentist and dental hygienist in child dental care

In a field project in the Public Dental Service in Norway, 4000 children aged 5 to 18 years were examined and given preventive care by dental hygienists. The study describes the clinical time spent providing child dental care when hygienists examined all children and referred to dentists those children who required care hygienists were not qualified to deliver. Of all clinical time spent, 56% was dentist time and 44% was hygienist time. A high proportion of children without dental caries did not consume dentist resources at all. More than 40% of the dentist time was consumed by the 10% of the children with most new decayed teeth. In conclusion, the project showed that in a child population with low caries increment, a substantial proportion of children received all dental care from hygienists, so that dentist resources were saved for other groups. However, although hygienists were used as first-line personnel, a considerable quantity of dentist time was spent on dental care for children.

[c-myc gene and p53 protein expression in human primary liver carcinoma]

Photobiotin-labelled c-myc gene probe was used to study primary liver carcinoma (PHC) by in situ hybridization on the paraffin sections as well as immunohistochemistry staining for p53 protein expression in 42 cases from high liver cancer incidence regions. The results are as follows: c-myc gene and p53 protein expression were both located in the nuclei. The positive incidences of overexpression of both c-myc gene and p53 protein in PHC were 76% and 55% respectively. The distribution and strength of the overexpression of c-myc gene and p53 protein in PHC are related to the degree of cell differentiation and the overexpression in the liver tissue surrounding the carcinoma is lower than that detected in the PHC tissue.

Alterations of tumor suppressor genes and allelic losses in human hepatocellular carcinomas in China

Aflatoxin B1 has been suggested as a causative agent for a G to T mutation at codon 249 in the p53 gene in human hepatocellular carcinomas (HCC) from southern Africa and Qidong in China. The objective of the present work was to test the hypothesis that exposure to aflatoxin B1 either alone or coincident with other environmental carcinogens might be associated with allelic losses occurring during development of human hepatocarcinogenesis in China. The HCCs were obtained from two different areas in China: Qidong, where exposure to hepatitis B virus (HBV) and aflatoxin B1 is high; and Beijing, where exposure to HBV is high but that of aflatoxin B1 is low. We analyzed the tumors for mutations in the p53 gene and loss of heterozygosity for the p53, Rb, and APC genes and at marker loci on chromosomes 4, 13, and 16. Frequencies of mutation, loss, and aberration (mutation and loss) of the p53 gene in 25 HCCs from Qidong were 60, 58, and 80%, respectively. The frequencies in 9 HCCs from Beijing were 56, 57, and 78%. However, the frequency of a G to T transversion at codon 249 in HCCs from Qidong and Beijing were 52 and 0%, respectively. These data indicate that mutation and/or loss of heterozygosity in the p53 gene, independent of the 249 mutation, play a critical role in the development of hepatitis B virus-associated HCCs in China. Loss of the Rb and APC genes was observed in 44 and 7% of HCCs from Qidong, respectively. Allelic losses on chromosome 4 and especially on chromosome 16 were frequent in HCCs from Qidong but were not observed in HCCs from Beijing, while loss of heterozygosity on chromosome 13 occurred at similar frequency in both Qidong and Beijing. These results show a distinct difference in the pattern of allelic losses between HCCs in Qidong and Beijing and suggest that aflatoxin B1 and/or other environmental carcinogens may contribute to this difference.

Aberrations of p53 gene in human hepatocellular carcinoma from China

Allele losses and mutations have been examined in 38 cases of primary hepatocellular carcinomas (HCC) from different geographic areas of China by Southern, single-strand conformational polymorphism (SSCP) and direct DNA sequencing analyses. Two of 12 samples from Qi-Dong and six of 18 HCCs from Shanghai showed loss of heterozygosity (LOH) at the loci on chromosome 17p13.3. All of the nine mutations in the p53 gene detected in HCC from Qi-Dong were clustered at the third base of codon 249, i.e. G:C to T:A, leading to an arginine to serine change. In contrast, 18 HCC samples from Shanghai contained three mutations at codons 249, 255 and 279. These results suggested a relationship between the spectrum of p53 aberration and environmental risk factors in these two geographic areas. Since no correlation between the state of HBV DNA and p53 aberration was observed, other factors such as dietary exposure to aflatoxin B1 (AFB1) might be responsible for the mutational hotspot at codon 249 in HCCs from Qi-Dong area.

[Clinical and pathological features of primary hepatocellular carcinoma in 26 patients survived over 10 years after operation]

The clinical and pathological features of primary hepatocellular carcinoma (PHC) in 26 patients who had survived over 10 years after operation were analyzed. The results were as follows: 84.62% (22 patients) were detected by AFP screening, 80.77% (21 patients) were in clinical stage I, 76.96% (20 patients) were younger than 45 years of age. Serum AFP of all patients turned negative within 2 months after operation. The tumor diameters ranged from 1.2 cm to 15 cm, and solitary tumors accounted for 80.77% (21 patients). All tumors were encapsulated and infiltrated by lymphocytes. Cirrhosis was found only in 9 cases (34.62%). The positive rates of HBsAg and HBcAg were 80% and 15% respectively in hepatic tissues surrounding the carcinoma. These results suggest that good prognosis or long survival is related to early detection, younger age of the patient, solitary tumor, better encapsulation, mild injury of the surrounding liver tissues, and rapid negative turning of AFP after operation.

Mutational hotspot in the p53 gene in human hepatocellular carcinomas

Human hepatocellular carcinomas (HCC) from patients in Qidong, an area of high incidence in China, in which both hepatitis B virus and aflatoxin B1 are risk factors, were analysed for mutations in p53, a putative tumour-suppressor gene. Eight of the 16 HCC had a point mutation at the third base position of codon 249. The G----T transversion in seven HCC DNA samples and the G----C transversion in the other HCC are consistent with mutations caused by aflatoxin B1 in mutagenesis experiments. No mutations were found in exons 5,6,8 or the remainder of exon 7. These results contrast with p53 mutations previously reported in carcinomas and sarcomas of human lung, colon, oesophagus and breast; these are primarily scattered over four of the five evolutionarily conserved domains, which include codon 249 (refs 4-9). We suggest that the mutant p53 protein may be responsible for a selective clonal expansion of hepatocytes during carcinogenesis.

[Pathologic analysis of primary hepatocellular carcinoma in 19 cases surviving over 10 years]

Pathological study was undertaken in 19 PHC patients who had survived over 10 years after operation. The pathological characteristics of the specimens were as follows: (1) Tumors less than 5 cm in diameter accounted for 78.9% (15/19), of which 13 PHC less than or equal to 3 cm in diameter. (2) Solitary tumors were found in 78.9% (15/19). (3) Sixteen out of nineteen (84.2%) cases had peritumor-fibrous encapsulation, and 13 cases had fibrolamellar structures in cancerous foci. (4) 14 out of 19(73.7%) cases were found to have lympholeukocyte infiltration in cancerous foci or encapsulation. (5) Liver cirrhosis was found in only 42.1% (8/19) of all cases and 75% of them were slight cirrhosis. These were the pathological background accounting for long survival duration of PHC patients. The authors suggest that early detection, diagnosis, and treatment be done in this period, for better opportunity of survival in PHC patients.