Ablation of demineralized dentin using a mid-infrared tunable nanosecond pulsed laser at 6 µm wavelength range for selective excavation of carious dentin.

In dental clinic, some lasers have already realized the optical drilling of dental hard tissue. However, conventional lasers lack the ability to discriminate and excavate carious tissue only, and still depend on the dentist's ability. The objective of this study is to develop a selective excavation of carious dentin by using the laser ablation with 6 µm wavelength range. Bovine dentin demineralized with lactic acid solution was used as a carious dentin model. A mid-infrared tunable pulsed laser was obtained by difference-frequency generation technique. The wavelength was tuned around the absorption bands called amide 1 and amide 2. In the wavelength range from 5.75 to 6.60 µm, the difference of ablation depth between demineralized and normal dentin was observed. The wavelength at 6.02 µm and the average power density of 15 W/cm(2), demineralized dentin was removed selectively with less-invasive effect on normal dentin. The wavelength at 6.42 µm required the increase of average power density, but also showed the possibility of selective ablation. In the near future, development of compact laser device will open the minimal invasive laser treatment to the dental clinic.

A tentorial dural arteriovenous fistula successfully treated with interruption of leptomeningeal venous drainage using microvascular Doppler sonography: case report.

BACKGROUND: Complete interruption of a dural arteriovenous fistula (DAVF) has been confirmed intraoperatively by visual inspection and intraoperative angiography. To confirm complete interruption of the shunt flow during the surgical treatment of a tentorial DAVF, we used intraoperative microvascular doppler monitoring. CASE DESCRIPTION: A 71-year-old man suffered from severe subarachnoid hemorrhage. Angiography showed a tentorial DAVF with pure leptomeningeal drainage associated with a venous pouch. After the patient's neurologic condition had improved, he underwent interruption of the draining vein via a right suboccipital approach. An arterialized drainage vein was easily identified by applying the microvascular doppler probe to the shunting vessels and was completely obliterated by clipping. There were no complications associated with use of the microvascular doppler. The postoperative course was uneventful and follow-up angiography showed complete obliteration of the DAVF. CONCLUSION: Intraoperative microvascular doppler monitoring is a useful technique not only for evaluating arterialized leptomeningeal drainage veins but also for confirming the complete obliteration of these vessels.

Treatment of tuberculum sellae meningiomas:a long-term follow-up study.

Surgical techniques and their results for tuberculum sellae meningiomas were studied. Thirty-three cases, the first of which was operated in 1980, were analysed. There were 4 men and 29 women with an average age of 46.7 years. Eight cases underwent reoperations. The mean follow-up was 10.7 years. Approaches were pterional for 15 patients, FOZ/FO for 10, bilateral subfrontal for 6, and others for 2. Simpson's grade (I, II, III, IV) were 12, 9, 0, and 12 cases respectively. Recurrence rate was 0% for grade I and 58.3% for grade IV. The FOZ/FO approach resulted in a lower Simpson's grade (P=0.05), but other factors were not related to Simpson's grade (P=0.05). The postoperative visual outcome did not depend on total (grade I and II) or subtotal (grade III and IV) removal (P=0.01). We conclude that radical removal of the tumours may result in lower recurrence rate without increasing surgical complications. Furthermore, skull base approaches can improve the rate of radical removal of tuberculum sellae meningiomas.

[Clinical experiences in the Liver Unit, the Queen Elizabeth Hospital, United Kingdom].

The present status of liver transplantation in th UK is described based on our clinical experience in the Liver Unit, Queen Elizabeth Hospital. In 1999, there were 161 cadaveric liver transplantations in the Liver Unit. The shortage of suitable donors for transplantation is widely recognized and is a worldwide problem. In order to solve this problem, "marginal donors" who would usually be refused on medical grounds have been used, and split-liver transplantation procedures have been developed in the Liver Unit.

Immunological reconstitution after cord blood transplantation for an adult patient.

We transplanted 4.1x10(7) unrelated umbilical cord blood cells into a 27-year-old patient suffering from transformed acute myelocytic leukemia. The thawing method was the same as described by Rubinstein et al (Proc. Natl. Acad. Sci. USA 1995; 92: 10119-10122). ANC reached over 500x10(9)/l on day 19, and the patient was free from RBC and platelet transfusion on days 26 and 38, respectively. Cytogenetic and molecular analysis after transplant revealed complete chimerism. The CD3+CD4+ lymphocyte count became greater than 100x10(9)/l at 5 weeks after transplantation. The CD3+CD8+ count became greater than 500x10(9)/l at 7 weeks and thereafter progressively increased in spite of administration of CYA. This immunological reconstitution pattern after umbilical cord blood transplantation was different from that after bone marrow transplantation, and resistance of CD3+CD8+ lymphocytes to CYA was the distinguishing characteristic. The rapid hematological recovery and immunological reconstitution may be attributed to the high dose of transfused nucleated cells and umbilical cord blood transplantation may become a promising method for treatment for such cases.

Bromocriptine-induced apoptosis in pituitary adenoma cells: relationship to p53 and bcl-2 expression.

In an attempt to understand the roles of the tumour suppressor gene p53 and the proto-oncogene bcl-2 in cell death and survival in pituitary adenomas, we investigated the relationship of their expression to the apoptotic response of two pituitary adenoma cell lines (GH3 and AtT-20) to bromocriptine. An MTT (3-4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrasolium bromide) assay was performed after treatment with bromocriptine for various periods of time over a range of concentrations to determine the effect of this drug on cell growth. Bromocriptine inhibited growth of GH3 and AtT-20 cells in a dose dependent manner. DNA fragmentation was assessed in GH3 and AtT-20 cells exposed to 10 ug/ml bromocriptine- for 48 h and 72 h. The DNA of GH3 and AtT-20 cells showed nucleosomal fragmentation, indicative of apoptosis. When assayed 2 days after adding bromocriptine, approximately 60% of GH3 and 58% of AtT-20 cells treated with bromocriptine displayed typical apoptotic morphology, including condensed chromatin and fragmented nuclei. There was a time dependent increase in the proportion of all tumour cells undergoing apoptosis. Decreased expression of bcl-2 and accumulation of wild-type p53 were associated with bromocriptine induced apoptosis in pituitary adenoma cells. DNA analysis confirmed the results obtained by the protein study. Different expression of p53 and bcl-2 genes is consistent with the expression of these gene products. These findings show that bromocriptine activated wild-type p53 and suppressed bcl-2 favouring occurrence of apoptosis in pituitary adenoma cells. Copyright 1999 Harcourt Publishers Ltd.

Prevalence of insomnia and its relationship to the health habits or status of women living along a city road part 1. epidemiologie study.

The prevalence rate of insomnia among 424 married women and its associated factors were surveyed. Insomnia is defined as having one of the following symptoms one or more times per week: difficulty inducing sleep (Fl), difficulty maintaining sleep (F2), early morning awakening (F3), light sleep (F4), or worry about poor sleep quality (F5). Poor sleep as a whole in the past one month (F6) was also inquired about. Percentages of Fl, F2, F3 and F5 among the subjects in their sixties were 21.3%, 13.3%, 6.7% and 10.7%, respectively, relatively higher than those of subjects in their thirties or forties. There was a significant difference in the percentage of F6 among four age categories (p < 0.05), and the percentage of F6 was highest (23.3%) in those in their thirties. Depressive state correlated with six insomnia items, Fl to F6 (rs.=-0.195, -0.161, -0.117,-0.221, -0.176, 0.284, respectively). Perceived health status correlated with Fl (-0.237), F4 (-0.213), F5 (-0.259), and F6 (0.373). Present medical condition correlated with Fl (-0.195), F3 (-0.146), and F5 (-0.220). The prevalence rates of insomnia for subjects in their thirties, forties, fifties and sixties were 16.7%, 17.7%, 25.7%, and 24.0%, respectively. Increases in the percentages of difficulty in inducting and maintaining sleep, early morning awakening and worry about poor sleep quality in the subjects in their sixties, and sleep dissatisfaction of those in their thirties were recognized.

Relationship between self-rating and polygraphic sleep parameters - analysis of compiled data from 12 young Japanese adults -.

An examination of the relationship of the self-rating sleep score to polygraphic sleep parameters was conducted. The self-rating sleep questionnaire, OSA, includes five sleep quality factors: sleepiness (Fl), sleep maintenance without interruption (F2), worry about daily life or poor emotional condition (F3), integrated or perceived sleep feeling (F4) and sleep initiation or induction (F5). Polygraphic sleep parameters including each sleep stage in minutes were used. If intercorrelation coefficients exceeded 0.8, only one of the related parameters was selected for multivariate analysis. Twelve male students slept a total of 88 nights, among which the first night was not included, in an experimental room. When absolute values of Spearman's rank correlation coefficient of not less than 0.4 were tentatively selected, the following pairs were extracted: F2 score and S1 (-0.423) or S3+S4 (0.409), F5 score and sleep latency (-0.439). Deeper sleep was closely associated with sleep maintenance without interruption. Agreement between self-rating and a polygraphic sleep parameter was recognized between the F5 score and sleep latency. Each OSA factor score was predicted by other polygraphic sleep parameters using multiple regression analysis. MT significantly contributed to the Fl, F3 and F4 scores. The number of stage shifts per night significantly contributed to the Fl and F3 scores, and the number of sleep spindles significantly contributed to the F5 score. Though prediction of sleep quality by polygraphic sleep parameters is limited, the association between concrete subjective and objective sleep parameters was clarified as mentioned above, and their practical meaning was partially elucidated.

Effect of air pollution on respiratory symptoms of junior high school students in Indonesia.

In 1994, 16,187 junior high school students were surveyed in Jakarta and surrounding cities, Indonesia, to study the effect of air pollution on respiratory illnesses. Nitrogen dioxide (NO2) was measured by the filter badge developed by Yanagisawa and Nishimura as a measure of air pollution. The average concentration of NO2 is the highest in central Jakarta and Tangerang (22-30 ppb), the lowest in rural areas (5-11 ppb), and in other cities, 11-20 ppb. Self-administered questionnaires were given to the students in 29 schools to obtain respiratory symptoms of cough, phlegm and wheeze. A significant relationship was found in this study between NO2 exposure levels and prevalence rates of cough, phlegm, and wheezing without cold, which were 27.7 to 38.7%, 15.0 to 21.9%, and 1.4 to 2.9%, respectively. Prevalence rates of persistent cough and persistent phlegm were 7.3 to 10.8% and 4.5 to 5.0% respectively. These rates were higher than those found by other researchers. This difference may be partly due to the survey methods. The more polluted, the higher the prevalence rate of respiratory symptoms.

Mitotic and meiotic stability of the CAG repeat in the X-linked spinal and bulbar muscular atrophy gene.

X-linked spinal and bulbar muscular atrophy (SBMA) occurs due to an expansion of the trinucleotide repeat (CAG)n in the androgen receptor gene. Anticipation is relatively rare in SBMA in contrast to spinocerebellar ataxia type 1 (SCAl), and dentatorubral and pallidoluysian atrophy (DRPLA) which show obvious paternal anticipation. The differences in the CAG repeat number were compared among sperm, leukocytes and skeletal muscles of SBMA patients. In SBMA, the sperm of most patients and the skeletal muscle of all patients showed the same repeat number as their leukocytes, whereas the increase in the repeat number from leukocytes to sperm was evident in SCA1 and DRPLA patients. The higher mosaicism level in sperm compared with leukocytes was common in SBMA, SCA1 and DRPLA, and the level of sperm was lower in SBMA than in SCA1 and DRPLA. Thus, spermatogenesis was suggested to be strongly associated with paternal anticipation. The mosaicism level was smaller in SBMA than in other (CAG)n expanded disorders, and smallest in the SBMA carrier females. These findings demonstrate that the CAG repeat in SBMA is relatively stable in mitotic and meiotic, processes, and there is a possibility that the lower mosaicism level of the carrier females compared with the SBMA patients is associated with X-linked recessive inheritance.

Relationships between mean lead levels in the atmosphere and in blood from data published since 1977.

The authors attempted to confirm the reliability of the linear log-log model presented by Goldsmith and Hexter in 1967. The data used were from seven reports published since 1977, including that of the authors. The age of the subjects in these reports ranged from three to over 65 years. Various methods of air sampling and pre-treatment of collected particulate matter were employed. Lead was determined by atomic absorption spectrophotometry. The mean value of lead in the atmosphere ranged from 0.11 to 19 micrograms/m3. A regression line obtained from 13 pairs of averaged lead in the atmosphere and in blood was log(Pb-B) = 0.259 x log(Pb-A) + .243, and the Pearson's moment correlation coefficient between the logarithm of Pb-A and the logarithm of Pb-B was 0.839. These results were roughly the same as those of Goldsmith. This finding confirms the consistency of the association between Pb-A and Pb-B, which may be used to monitor atmospheric and blood lead quantitatively in those countries conducting a lead reduction program in gasoline.

[A case-control study on the risk factors of sudden death. An analysis of 44 cases in a company by health care records].

A case-control study was conducted on sudden deaths in a company having about 40,000 workers to determine the risk factors of sudden death. Sudden death was defined as internal death within 24 hours from the onset of the event. Two controls whose sex and age were matched with a case were selected from the employees of the company. The risk factors studied were age, sex, obesity, blood pressure, serum glucose, total cholesterol, triglyceride, uric acid, urinary, protein, urinary sugar, electrocardiographic (ECG) findings, diabetes mellitus, smoking history and drinking history. These data were collected from the latest health care record including health examinations performed annually in the company. t test, U test and Fisher's test were applied to each of the variables. Multiple logistic regression analysis and canonical discriminant analysis were applied, using mean systolic blood pressure for 5 years, body mass index (BMI), abnormal Q wave on ECG, and serum glucose as explanatory variables. From 1984 to 1990 44 sudden death cases composed of 42 males and two females were identified. The age-specific mortality rate increased exponentially with age with a peak at the sixth decade. The most frequent cause of sudden death was heart disease (77%) followed by cerebrovascular disease (18%). Statistical analysis showed that significant risk factors were high blood pressure, low BMI, diabetes mellitus, and ST-T change on ECG.

Mutagenicity of benzotrichloride and related compounds.

Benzotrichloride (BTC), benzal chloride (BDC), benzyl chloride (BC) and benzoyl chloride (BOC) were surveyed for their mutagenicity in microbial systems such as rec-assay using Bacillus subtilis and reversion assays using E. coli WP2 and Ames Salmonella TA strains with or without metabolic activation in vitro. BTC and BDC required metabolic activation for their mutagenic activities in several strains of E. coli and Salmonella. The mutagenic metabolites of these compounds may not have been produced by hydrolysis. BC was weakly mutagenic without metabolic activation. Only BOC exhibited no mutagenic activity in the detection procedures used. The mutagenic metabolite of BTC might be very unstable under our experimental conditions. The strain E. coli WP2 try hcr was more sensitive than E. coli B/r WP2 try (hcr+) with regard to the mutagenicity of BTC.

A temperature sensitive mutant of Escherichia coli which does not allow replication of RNA phage at a high temperature.

A conditional mutant, referred to as RepR43, was isolated from Escherichia coli W2252 by N-methyl-N'-nitro-N-nitroso-guanidine mutagenesis. Although RepR43 does not permit growth of RNA phage beta at the restrictive temperature, 43 degrees C, cell growth and synthesis of macromolecules such as RNA and protein continue at a somewhat reduced rate. Several lines of evidence indicate that a RepR43 function is indispensable for normal phage RNA replication. In addition, this function appears to be involved in the maintenance of the perpetuated phage genome. The addition of 10% sucrose to the medium at the restrictive temperature resulted in the production of the phage, suggesting that the mutant cell might have an altered membrane organization which interferes with normal viral replication.

Mutagenicity of N-butyl-N-(4-hydroxybutyl)nitrosamine, a bladder carcinogen, and related compounds.

N-Butyl-N-(4-hydroxybutyl)nitrosamine (BBN), which specifically induces bladder tumors, was shown to be mutagenic to Salmonella typhimurium strains TA 1535 and TA100 in the presence of an S-9 mix prepared from the liver of rats treated with polychlorinated biphenyl. Reduced nicotinamide adenine dinucleotide was a more effective cofactor than reduced nicotinamide adenine dinucleotide phosphate in the activation of BBN by the rat liver S-9 fraction, N-Butyl-N-(3-carboxypropyl)nitrosamine, reported to be the main urinary metabolite of BBN as well as of N,N-dibutylnitrosamine and to induce urinary bladder tumors specifically, was found to be mutagenic without metabolic activation by the S-9 mix. The mutagenicities of 31 compounds related structurally or metabolically to BBN and N,N-dibutylnitrosamine were tested. Of these compounds, 13 have previously been demonstrated to be carcinogenic, and nine have been shown to be noncarcinogenic. All the carcinogenic compounds were found to be mutagenic to strain TA1535 with or without the S-9 mix. Four of the nine noncarcinogenic compounds were also mutagenic. These "false-positive" compounds were predicted, in fact, to be carcinogenic.