Stim1 Regulates Enamel Mineralization and Ameloblast Modulation.

Loss-of-function mutations in the Ca2+ release-activated Ca2+ channel genes ORAI1 and STIM1 abolish store-operated Ca2+ entry (SOCE) and result in ectodermal dysplasia with amelogenesis imperfecta. However, because of the limited availability of patient tissue, analyses of enamel mineralization or possible changes in ameloblast function or morphology have not been possible. Here, we generated mice with ectodermal tissue-specific deletion of Stim1 ( Stim1 cKO [conditional knockout]), Stim2 ( Stim2 cKO), and Stim1 and Stim2 ( Stim1/2 cKO) and analyzed their enamel phenotypes as compared with those of control ( Stim1/2fl/fl) animals. Ablation of Stim1 and Stim1/2 but not Stim2 expression resulted in chalky enamel and severe attrition at the incisor tips and molar cusps. Stim1 and Stim1/2 cKO, but not Stim2 cKO, demonstrated inferior enamel mineralization with impaired structural integrity, whereas the shape of the teeth and enamel thickness appeared to be normal in all animals. The gene expression levels of the enamel matrix proteins Amelx and Ambn and the enamel matrix proteases Mmp20 and Klk4 were not altered by the abrogation of SOCE in Stim1/2 cKO mice. The morphology of ameloblasts during the secretory and maturation stages was not significantly altered in either the incisors or molars of the cKO animals. However, in Stim1 and Stim1/2 cKO incisors, the alternating modulation of maturation-stage ameloblasts between the smooth- and ruffle-ended cell types continued beyond the regular cycle and extended to the areas corresponding to the zone of postmodulation ameloblasts in the teeth of control animals. These results indicate that SOCE is essential for proper enamel mineralization, in which Stim1 plays a critical role during the maturation process.

Clinical electroencephalographic study of nine pediatric patients with convulsion induced by the TV animation, Pocket Monster.

BACKGROUND: To determine the usefulness of a few types of photic stimulation in patients with photo-convulsive response. METHODS: A clinical electroencephalographic study was conducted in nine children who developed convulsions and other symptoms while they watched the TV animation and were subsequently treated at the hospital. Photic stimulation was applied with their eyes open or closed. Another photic stimulation was applied with the video tape of the animation. RESULTS: A photoparoxysmal response (PPR) was never seen in the electroencephalographs (EEG) in any of these patients when photic stimulation was applied with their eyes closed, while PPR was seen in three of seven patients when photic stimulation was applied with their eyes open. Two patients (siblings) showed no specific abnormality when photic stimulation was applied with their eyes either open or closed. However, myoclonus and PPR appeared when the EEG was conducted while they watched the video tape of the animation under supervised conditions. CONCLUSIONS: In a society where people are exposed to abundant TV games, TV animation or videos, self-restraint or regulations of frequent use of flickering scenes is thought to be necessary. However, it is also thought to be necessary to conduct EEG by applying photic stimulation, not only with the eyes closed, but also with the eyes opened or by applying flickering red light stimulation, which is emitted from a strong light source, or a combination of two colors, such as red and blue or red and green, in patients with suspected photosensitivity.

[Efficacy of rectal diazepam suppository in the prophylaxis of febrile seizures: comparison with rectal chloral hydrate suppository].

We evaluated the efficacy of diazepam and chloral hydrate given rectally for the prophylaxis of recurrence of febrile seizure. The dose were 0.4 mg/kg for diazepam and 250 mg (for children younger than 3 years old) or 500 mg (for over 3 years old) for chloral hydrate. Another dose was given after an interval of 8 hours if body temperature continued to exceed 38.0 degrees C. Among the 452 patients with febrile seizures who visited our hospital from Jan. 1993 to Jun. 1995, 113 were studied who had at least one febrile episode in the follow-up period that extended over 6 months. These patients were divided into two groups: Group D (72 patients given diazepam) and Group C (41 patients given chloral hydrate). In group D and C, the numbers of febrile episodes were 238 and 167, and those of recurrent seizures 8 (3.8%) and 29 (20.4%), respectively. The recurrences rate was significantly higher in the latter group (p < 0.005). There was no statistical difference as to the mean dosage of diazepam or chloral hydrate between the patients with and without recurrence. The numbers of patients with seizure recurrence were 8 (11.1%) in group D and 12 (29.3%) in group C, being significantly larger in the latter (p < 0.005). Diazepam produced more adverse effects than chloral hydrate did. Thus diazepam suppositories for the prevention of recurrence of febrile seizures were more effective than chloral hydrate suppositories.

[Rhythmic alpha/theta bursts in the electroencephalogram of early premature infants: (1). The features in normal early premature infants].

Rhythmic alpha/theta bursts were studied on forty-nine electroencephalographic records of early premature infants, ranging from 25 to 30 weeks of conceptional ages. Frontal alpha bursts and occipital theta bursts were prominent at 25-26 weeks, and temporal theta bursts prominent at 27-28 weeks. Frontal, temporal and occipital alpha/theta bursts were observed unilaterally, when all rhythmic bursts were seen frequently. Frontal and temporal bursts appeared often on the left side and occipital bursts on the right side.

[Rhythmic alpha/theta bursts in the electroencephalogram of early premature infants: (2). Correlation with background EEG activity].

Rhythmic alpha/theta bursts were studied on ninety-five electroencephalographic records of early premature infants, ranging from 25 to 30 weeks of conceptional ages in relation with background EEG activity. When background EEG showed normal, frontal alpha bursts and occipital theta bursts were prominent at 25-26 weeks, and temporal theta bursts at 27-28 weeks. A significant decrease in all rhythmic bursts on the frontal, temporal and occipital areas, was seen in early premature infants showing severe background EEG depression. Incidence of rhythmic alpha/theta bursts varies inversely with depression of background EEG activity.

[Malignant lymphoma with various neuropsychological symptoms].

A case of malignant lymphoma presented with various neuropsychological symptoms which made it difficult to achieve the diagnosis and therapy. A 9-year-old boy was referred to our hospital with complaints of psychological symptoms, impairment of consciousness and generalized convulsive seizures. A lumbar puncture revealed infiltration of numerous blasts which were positive for immature B cell markers. CT scan showed a mass in the right ethmoidal sinus, but no space occupying lesion in the brain. The tumor cells in the right ethmoidal sinus had the same phenotypes as those in the CSF. Thus a diagnosis of non-Hodgkin's lymphoma, developing in the right ethmoidal sinus and infiltrating into the central nervous system, was established. The blast cells in the liquor and the tumor of the right ethmoidal sinus disappeared after induction of systemic chemotherapy, irradiation and intrathecal chemotherapy. However, intracranial bleeding occurred during the chemotherapy. He died of respiratory failure 10 months after the start of treatment.

[Human parvovirus B19 infection in patients with hematologic disorders on chemotherapy].

We described two cases having erythroid hypoplasia and pancytopenia, respectively, caused by human parvovirus B19 (PVB19) infection on chemotherapy. The first patient was a seven-year-old boy with Non-Hodgkin's lymphoma. He has obtained complete remission with LSA2L2 protocol, but, immediately after this remission, he suddenly developed high fever, erythema on cheeks and severe anemia without reticulocytes. We concluded that the cause of anemia and other symptoms were due to PVB19 infection because PVB19 DNA in his serum was detected by dot blot hybridization and polymerase chain reaction, although specific antibodies to PVB19 remained absent. He received gamma-globulin intravenously (200mg/kg/day for 5 days). The fever and erythema were improved promptly, but viremia and anemia lasted a few weeks and the specific antibodies to PVB19 were negative for about two months thereafter. The second patient was a nine-year-old boy with common ALL in remission. Pancytopenia suddenly occurred under maintenance therapy. Because IgM to PVB19 was detected in his serum, the patient was diagnosed to have temporary pancytopenia due to PVB19 infection. In conclusion, it is important to confirm specific antibodies and PVB19 DNA in serum when anemia or pancytopenia of unknown cause occurs in immunocompromised patients receiving chemotherapy.