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.

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.

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.

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.

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.

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.

Non-pressure adhesion of a new adhesive restorative resin

Non-pressure adhesion of a new adhesive restorative resin was investigated employing a new tensile test. The material was adhesive to both enamel and dentin as well as to carious dentin and showed strong adhesion to all substrates tested. Etching further increased the adhesion even to dentin.

Effect of a carious dentin softener on the dentin and pulp

The application of GK-101 to carious dentin softens the first or outer layer which contains denatured collagen. The second or inner layer of carious dentin, containing normal collagen fibers, is unaffected. The pulps of dog teeth were not affected by applying the solution to freshly prepared sound dentin.

Penetration of elements from amalgam into dentin

Penetration of amalgam elements into dentin was investigated by electron probe microanalysis of human and dog teeth. Penetration was observed with tin and zinc, but not with mercury or silver; it was observed only in the softened dentin. The elements were accumulated mainly in the second decalcified layer of dentin.