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Biomedical subjects

N Kurosaki

Publications and source records attributed to N Kurosaki.

At least 19 recordsLinked to original sources

Mass screening for neuroblastoma at 6 months of age: difficult to justify.

BACKGROUND/PURPOSE: A statistical analysis of the mass screening for neuroblastoma in Japan based on a population study rarely has been reported. This study aims to evaluate retrospectively the effectiveness of mass screening at 6 months of age using the available population data. METHODS: The data on the neuroblastoma cases registered by the Committee for Pediatric Solid Malignant Tumors in the Kyushu area were analyzed based on both screened and unscreened populations in the Kyushu area. RESULTS: From 1988 to 1992, the cumulative incidence of neuroblastoma in children less than 5 years of age was 82 in 484,599 for screened children, and 11 in 92,966 for unscreened children, respectively. Fourteen of the 82 screened patients had negative findings at 6 months of age (MS-negative cases). No significant difference was observed in the cumulative mortality rates from neuroblastoma in children younger than 5 years of age between the screened children and the unscreened children. Six of seven patients who died among the screened children were MS-negative cases with stage III or IV disease. In addition, no significant difference was found in the cumulative mortality rates from the neuroblastoma cases in patients less than 5 years of age between the children screened from 1988 to 1992 (7 of 484,599) and all children from 1980 to 1984 (14 of 668,084). CONCLUSIONS: These findings suggests that the majority of the patients detected by mass screening had a favorable prognosis, and, mass screening in Japan for children less than 6 months of age was not observed to reduce the incidence and mortality from neuroblastoma. Therefore, mass screening at 6 months of age was not found to improve substantially the prognosis of patients with unfavorable neuroblastoma identified over 1 year of age, which is the primary purpose of such mass screening for neuroblastoma.

Evaluation Studies as Topic

Demonstration of putative Ca-binding domains in dentin matrix of rat incisors after daily injections of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP).

In order to clarify the initial process of dentin mineralization, the inhibitory effect of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) on dentin mineralization was investigated. Rats (100 g) were subcutaneously injected with HEBP (8 mg P/kg) for 7 or 14 d, and the incisors were processed for Ca histochemistry and/or electron microscopy. HEBP-treated incisors demonstrated ladder-like alternate rows of mineralized and non-mineralized dentin at the apical end. GBHA revealed moderate Ca reactions in the non-mineralized circumpulpal dentin matrix where electron microscopy revealed rich distribution of fine mesh-like electron-dense material. Non-mineralized mantle dentin matrix was negative for Ca but contained numerous matrix vesicles (MVs) filled with crystalline and/or amorphous mineral deposits. Mineralization of circumpulpal dentin occurred independently of MV-rich mantle dentin layer in affected specimens. Our data provide histochemical evidence of possible Ca-binding property of the circumpulpal dentin matrix and its absence in the mantle dentin where MV-mediated mineralization occurs. In the mantle dentin, HEBP does not interfere with crystal growth in MVs but inhibits its outgrowth after membrane rupture. It is proposed that circumpulpal dentin matrix has a potential to mineralize independently of MV-mediated mineralization of mantle dentin, although MVs determine the initial site and timing of dentin mineralization.

Aminophenols

[New curriculum of behavioral dentistry].

Faculty of Dentistry, Tokyo Medical and Dental University first introduced New Curriculum of Behavioral Dentistry in Japan. This curriculum has been established in consideration of the current social environments and dental clinical practice in our country, in addition to reference to Curriculum Guidelines in the USA. When students' impressions and assessments on the courses were researched and analyzed, the majority were found to be satisfied with this curriculum although several problems to be solved were also presented at the same time, such as timing of derivering lectures.

Behavioral Sciences

[Medical interview with simulated patients at behavioral science in dentistry].

The purpose of this paper is to present an outline of student's practice of interviewing simulated patients at behavioral science in dentistry. This practice was initiated as part of a newly introduced behavioral science course at our school of dentistry, to enable students to acquire communication skills, comprehensive understanding, and a proper attitude vis-à-vis patients. Students as well as instructors involved in the practice evaluated it as highly relevant for clinical education. It is concluded that the development of such practices in dental education is a prerequisite for training students to dentists oriented toward patient-centered dental practice.

Adult

[4-year clinico-statistical observation of outpatients].

Clinico-statistical observations were made on the outpatients visiting the Department of Initial Diagnosis and Emergency, Faculty of Dentistry Hospital, Tokyo Medical and Dental University in 1986, 1987, 1989 and 1990. The following findings were obtained according to sex, age group, and chief complaints of new outpatients. Approximately 60% of the outpatients were female during the year examined. The number of outpatients tended to increase in March and to decrease during the winter. The largest number of new outpatients visiting the hospital was in the 20-24-year-old group in both males and females. In the female patients, the 50-54-year-old group had a relatively higher peak. The greatest chief complaint was tooth pain. Further, the chief complaint involving oral soft tissues was due to inflammation. The main disease diagnosed due to chief complaints was caries in the 20-29-year-old group, marginal periodontitis in the 50-59, pericoronitis of wisdom tooth in the 20-29, temporomandibular joint problem in the < or = 19 and masticatory disturbance in the 60 < or = -year-old groups.

Adult

Renal cell carcinoma in a patient with Beckwith-Wiedemann syndrome.

We report the case of a patient with Beckwith-Wiedemann syndrome (BWS) who developed renal cell carcinoma (RCC). At birth, this patient presented with macroglossia, diastasis recti, mild gigantism, hepatomegaly and hypoglycemia, and the diagnosis of BWS was made. At 22 months, an intrapelvic rhabdomyosarcoma was detected and resected. At 37 months, computed tomography (CT) demonstrated a small mass with high attenuation in the right kidney, which was surgically confirmed to be RCC.

Beckwith-Wiedemann Syndrome

Mass screening for neuroblastoma: quo vadis? A 9-year experience from the Pediatric Oncology Study Group of the Kyushu area in Japan.

Since 1985, a nationwide program of mass screening for neuroblastoma has been available for 6-month-old infants throughout Japan. From 1985 to 1993, the authors studied 285 patients with neuroblastoma among their regional population of 15 million. There was an increase in the total number of patients per year in comparison to the previous 6-year period (1979 to 1984). However, no significant difference was noted in the number of patients older than 1 year or in the incidence of advanced-stage (stages III and IV) unscreened cases. The majority of neuroblastomas in the screened group showed favorable biological factors, even in the advanced stages. However, there was a small group with histologically and/or biologically unfavorable factors; five of 115 had amplified N-myc oncogene, four of 74 showed unfavorable Shimada histological findings, and three of 33 had an unfavorable DNA ploidy pattern. One case from this group with unfavorable factors died of the tumor. 3) Thirty-eight cases were negative at the time of mass screening, but later presented with neuroblastoma. Most of them were diagnosed between 1 and 3 years of age, and 30 of the 38 cases (78.9%) were advanced stage with unfavorable prognostic factors. Thus, the authors conclude that mass screening at 6 months can detect a selected population of infants with neuroblastoma; some of the tumors may represent subclinical masses destined for spontaneous regression. However, some tumors with unfavorable factors have been detected by mass screening before progression and/or dissemination. Infants in this group are considered to benefit most from early diagnosis and treatment.

Adolescent

Neuroblastoma in infants aged less than 6 months: is more aggressive treatment necessary? A report from the Pediatric Oncology Study Group of the Kyushu area.

Infants with neuroblastoma are known to have a better prognosis than older children. In Japan in 1985, mass screening for neuroblastoma in infants aged 6 months was introduced. With this policy, there has been an increase in the number of patients seen with neuroblastoma between 6 and 11 months of age. In a previous report the authors described the management and prognosis of infants with disease detected by mass screening, but there is still little information regarding the strategies of management for infants with neuroblastoma aged less than 6 months. The authors analyzed the data regarding 27 patients aged less than 6 months registered in their region (population 15 million) from 1985 to 1992, and compared it with that of the previous 8-year period. In the younger age group, there was a significantly higher rate of advanced disease stages (III and IV). In spite of the variation in treatment related to the choice of individual institutions, infants with stages I, II, and III disease had a good outcome, suggesting that aggressive chemotherapy is not necessary unless poor prognostic factors are present. One patient with stage IV disease died of disseminated disease and one with stage IVs and 22 copies of N-myc oncogene also died of tumor relapse in spite of aggressive chemotherapy. It is therefore concluded that the prognosis in infants with stage IV and IVs neuroblastoma under the age of 6 months is not as good as had previously been believed, and that such patients, therefore, require special consideration.

Antineoplastic Combined Chemotherapy Protocols

Molecular analysis of a patient with Beckwith-Wiedemann syndrome, rhabdomyosarcoma and renal cell carcinoma.

We described a patient with Beckwith-Wiedemann syndrome associated with rhabdomyosarcoma (RMS), and renal cell carcinoma (RCC). Karyotypes of peripheral lymphocytes and RMS cells were normal. DNA analyses showed maternal loss of heterozygosity (LOH) at 11p15 region in RMS but not in RCC. The insulin-like growth factor II gene (IGF2) was found to be expressed at a moderate level in RMS but not in RCC by in situ hybridization. Each of parental allele-derived IGF2 transcript was detected in RCC, while maternal allele-derived transcript was weak in RMS because of maternal LOH. These results suggest that (1) loss of imprinting (LOI) of IGF2 might be responsible for BWS, (2) on the other hand, LOI itself might not induce tumor occurrence in tissues where the control of tissue-specific expression of IGF2 is maintained, (3) increased expression of IGF2 due to maternal loss of a putative controller gene for IGF2 at 11p15 might predispose to sustaining tumorigenic mutations and tumor progression, (4) loss of a putative onco-suppressor gene at 11p15 might induce RMS occurrence. The cause of RCC was thought to be different from that of RMS.

Abdominal Neoplasms

The effect of etching on the dentin of the clinical cavity floor.

The most conservative cavity preparation, which takes full advantage of chemically adhesive composite resin, involves removal of only the infected outer carious dentin that is stainable by the caries detector. This preparation exposes in the cavity floor either the turbid layer at the top of the inner carious dentin or the underlying transparent layer. Examination by scanning electron microscope revealed that etching the cavity floor demineralized the intertubular dentinal surface slightly and produced tapered, cylindrical holes or ring-shaped holes at the dentinal tubule apertures of the turbid or transparent layer, respectively. The holes were blind with solid floors of intratubular crystal deposits of the transparent layer, suggesting that etching increases permeability little. Placement of the adhesive resin on the etched cavity floors produced a resin-impregnated dentinal layer and tapered, cylindrical or tubular-shaped resin tags, which apparently improved the bond and tubule aperture seal.

Acid Etching, Dental

Autosomal fragile site at 2q13 in a proband with mental retardation.

Folate sensitive fragile site on chromosome 2q13 was detected in a female proband with mild hypertrichosis, negativism, speech disorder, and severe mental retardation. The same chromosomal aberration was also detected in her mother with normal phenotype. Spontaneous expression of fragile site on 2q13 was also observed.

Adult

Vascular compromise in chronic volvulus with midgut malrotation.

Three cases of chronic volvulus of the small bowel in midgut malrotation are presented, all of whom manifested similar angiographic findings: proximal occlusion of the superior mesenteric artery and vein and development of collateral vessels. These findings may indicate the pathophysiology of chronic volvulus in midgut malrotation; the volvulus is progressive and eventually results in the twisting of the mesenteric root itself, but because of its chronic nature collateral circulation develops, eliminating bowel necrosis. Computed tomography (CT), performed in two cases, revealed dilated, tortuous vessels in the mesentery in addition to the known CT finding of a whirl-like pattern of the volvulated small bowel loops. Sonography, performed in one case, showed an unique feature of whirling sonolucent layers probably representing the volvulated small bowel loops intermixed with dilated mesenteric collateral vessels. We would like to emphasize the usefulness of CT and sonography in the early diagnosis of those cases with vague and nonspecific clinical manifestations.

Adolescent