Search for nucleon decay via n→ν[over ¯]π0 and p→ν[over ¯]π+ in Super-Kamiokande

We present the results of searches for nucleon decay via n→ν[over ¯]π0 and p→ν[over ¯]π+ using data from a combined 172.8  kt·yr exposure of Super-Kamiokande-I,-II, and-III. We set lower limits on the partial lifetime for each of these modes: τn→ν[over ¯]π0>1.1×10(33) years and τp→ν[over ¯]π+>3.9×10(32) years at a 90% confidence level.

Search for dinucleon decay into kaons in Super-Kamiokande

A search for the dinucleon decay pp → K+ K+ has been performed using 91.6  kton·yr data from Super-Kamiokande-I. This decay provides a sensitive probe of the R-parity-violating parameter λ112''. A boosted decision tree analysis found no signal candidates in the data. The expected background was 0.28±0.19 atmospheric neutrino induced events and the estimated signal detection efficiency was 12.6%±3.2%. A lower limit of 1.7×10(32)  years has been placed on the partial lifetime of the decay O16 → C14K+ K+ at 90% C.L. A corresponding upper limit of 7.8×10(-9) has been placed on the parameter λ112''.

Evidence for the appearance of atmospheric tau neutrinos in super-Kamiokande

Super-Kamiokande atmospheric neutrino data were fit with an unbinned maximum likelihood method to search for the appearance of tau leptons resulting from the interactions of oscillation-generated tau neutrinos in the detector. Relative to the expectation of unity, the tau normalization is found to be 1.42 ± 0.35(stat)(-0.12)(+0.14)(syst) excluding the no-tau-appearance hypothesis, for which the normalization would be zero, at the 3.8σ level. We estimate that 180.1 ± 44.3(stat)(-15.2)(+17.8) (syst) tau leptons were produced in the 22.5 kton fiducial volume of the detector by tau neutrinos during the 2806 day running period. In future analyses, this large sample of selected tau events will allow the study of charged current tau neutrino interaction physics with oscillation produced tau neutrinos.

Search for differences in oscillation parameters for atmospheric neutrinos and antineutrinos at Super-Kamiokande

We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande-I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best-fit antineutrino mixing is found to be at (Δm2,sin2 2θ)=(2.0×10(-3)  eV2, 1.0) and is consistent with the overall Super-K measurement.

CT angiography with helical CT in the assessment of acute stage of subarachnoid hemorrhage

PURPOSE

We evaluated the usefulness of helical CT in the preoperative assessment of ruptured cerebral aneurysms during the acute stage of subarachnoid hemorrhage (SAH).

METHODS

Nine patients with 13 aneurysms were included in this study. Helical CT scanning was performed before preoperative angiography. The section thickness and the table-movement speed were 1-2 mm/sec. Helical CT scanning was started 20 sec after the start of injection of 100 ml of contrast agent at a rate of 3 ml/sec.

RESULTS

The average CT value of SAH was 51.9 Hounsfield units (HU) and that of the aneurysm was 191.7 HU. Nine of 13 aneurysms greater than 3.0 mm in diameter were identified by three-dimensional CT angiography (3DCTA). In seven cases, the information provided by 3DCTA images, maximum intensity projection images, and multiplanar images, was very useful in surgical planning, providing information concerning the configuration of the neck and relationships between the aneurysm and brain parenchyma. Four aneurysms in two cases were not depicted by 3DCTA because they were located outside the imaging volume. This problem was overcome by changing the imaging volume according to the extent of origin of SAH.

CONCLUSION

We conclude that helical CT in patients with SAH is useful for surgical planning, providing valuable information that cannot be obtained by conventional angiography.

Antagonistic activities of N-3389, a newly synthesized diazabicyclo derivative, at 5-HT3 and 5-HT4 receptors

The antagonistic activities of compound N-3389 (endo-3,9-dimethyl-3,9- diazabicyclo[3,3,1]non-7-yl 1H-indazole-3-carboxamide dihydrochloride) at 5-HT3 and 5-HT4 receptors were examined using in vitro and in vivo assays. N-3389 showed potent 5-HT3 receptor antagonistic activities in a radioligand binding assay (pKi = 8.77), against 2-methyl-5-HT (2-Me-5-HT)-induced bradycardia in rats (ED50 = 0.73 micrograms/kg i.v., 38 micrograms/kg p.o.) and against 2-Me-5-HT-induced contraction in longitudinal muscle myenteric plexus preparations of guinea-pig ileum (IC50 = 3.2 x 10(-8) M). As a preliminary to investigating the effect of N-3389 on 5-HT4 receptors, we examined the contraction induced by 5-HT in guinea-pig ileum preparations. We confirmed that 5-HT (10(-8)-10(-5) M) induced biphasic contractions in the preparations. Furthermore, 5-HT3 receptor antagonism inhibited the late phase of the contraction induced by high concentrations of 5-HT (3 x 10(-6)-10(-5) M), whereas 5-HT4 receptor antagonism inhibited the early phase of the contraction induced by low concentrations of 5-HT (10(-8)-10(-6) M). N-3389 (10(-7)-10(-5) M) inhibited both phases of contraction induced by 5-HT. In addition, N-3389 (3 x 10(-7)-3 x 10(-6) M) was found to inhibit the increase of electrically stimulated twitch responses induced by 5-HT (10(-8) M) longitudinal muscle myenteric plexus preparation of the guinea-pig ileum. These results suggest that N-3389 acts as a 5-HT3 and 5-HT4 receptor antagonist.

Washington Psychosocial Seizure Inventory: a multiinstitutional study in Japan

No reports of the Washington Psychosocial Seizure Inventory (WPSI) have yet been presented from Asian countries in detail. We performed a multiinstitutional study of this test in 652 Japanese subjects. The mean value of the Lie Scale was high, and only one third of our subjects were under the limit of the original criterion; this has been the biggest obstacle to use of the validity scales of this test in Japan. The profile form of the clinical scales was very similar to those reported from other countries. According to the relation between clinical characteristics and the WPSI scales, seizure frequency showed the strongest influence. In a comparison of whole subjects, mean scores of the clinical scales in Japan remained at an intermediate value or lower. This result was obviously distorted by the high score of the Lie Scale. When comparison was restricted to cases with valid Lie Scale scores, the values of five clinical scales showed high levels. Therefore, Japanese patients among developed countries apparently showed relatively severe levels of problems. We conclude that the WPSI could be a useful examination in Japan to determine reliably the various psychosocial problems of epileptic persons, but use of the Lie Scale according to the original criterion is not practical. Modifications of the limitation may be needed.

[Intra-arterial chemotherapy with ACNU in the treatment of malignant gliomas]

Twelve patients with supratentorial gliomas were treated with intra-arterial ACNU followed by intravenous maintenance chemotherapy. Six of the patients, treated from February 1987 through May 1989, received doses of 120-200 mg/m2 (high dose treatment group); six patients, treated from June 1989 through October 1990, received doses of 80-100 mg/m2 (low dose treatment group). The drug was given via the supraophthalmic portion of the internal carotid artery or vertebral artery at a rate of 10 mg/min. The response rate (CR + PR) on CT scan was 50% (3/6) in the high dose treatment group and 17% (1/6) in the low dose treatment group. Survival periods from first operation, however, did not differ between the high and low dose treatment groups. Bone marrow suppression was dose-related and reversible at these doses. Severe neurotoxicities (hemiparesis and aphasia) developed in the patients who received 200 mg/m2 of ACNU; in one case, this was irreversible. High dose intra-arterial ACNU chemotherapy is effective in reducing tumor size on CT scan but the prognosis is not improved. The dose limiting factor of intra-arterial nitrosourea is neurotoxicity, and doses of more than 200 mg/m2 are considered to be dangerous.

Metastatic choriocarcinoma with neoplastic aneurysms cured by aneurysm resection and chemotherapy. Case report

A case of choriocarcinoma with brain and lung metastasis is reported. The patient was admitted for treatment of a cerebral hemorrhage from neoplastic aneurysms and, following removal of the hematoma and resection of the aneurysms, her carcinoma was successfully managed with chemotherapy. She has survived for 6 years after onset without neuroimaging evidence of recurrence. Surgical treatment of metastatic lesions followed by prolonged intensive chemotherapy are indicated for the improved prognosis of choriocarcinoma.

[Carotid-cavernous fistula successfully treated with embolization and radiation therapy: report of three cases]

Three cases of mixed internal and external carotid-cavernous fistula (CCF) were successfully treated with embolization of feeders from the external carotid artery (ECA) and focal irradiation to the cavernous sinus (CS). Cases 1 and 2 were females, 63 and 69 years old respectively, both with spontaneous left CCF. Case 3 was a 55 year old male with posttraumatic left CCF. Symptoms of case 1 were double vision, left chemosis and exophthalmos; those of case 2 were double vision, left retroobital pain, left forehead dysesthesia and blurred vision; and case 3 complained of double vision, left chemosis, left exophthalmos and pulsatile tinnitus. In all three cases, angiography disclosed left CCF fed by ipsilateral dural branches from the internal maxillary artery (IMA) and the internal carotid artery (ICA). In case 1, small branches from the ascending pharyngeal artery also fed the CS. In cases 2 and 3, feeders from the ECA were arising only from branches of the IMA. In case 3, hypertrophy of the meningohypophyseal trunk was visible. In cases 1 and 2, although the CS was opacified, feeders from the ICA were not clearly visible. Embolizations of branches of the IMA were performed in all cases using Ivalon under selective catheterization. In case 1, symptoms partially improved, but in cases 2 and 3, visual symptoms were transiently aggravated. Focal irradiation to the CS was done with total doses of 30, 30 and 40 Gy each for cases 1, 2, and 3 respectively. In case 1, clinical symptoms gradually improved about one third way through irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring of cortical blood flow during excision of arteriovenous malformation by thermal diffusion method

The cortical blood flow adjacent to arteriovenous malformations was monitored in six patients before, during, and after excision of arteriovenous malformations using a thermal diffusion probe. In a large arteriovenous malformation, a progressive increase in cortical blood flow up to two times the preexcision value was noted with occlusion of the feeding arteries. Lowering arterial pressure to keep normal cortical blood flow during and after operation resulted in minimum brain edema and an excellent result. Direct measurement of cortical blood flow is of value in determining the precise level of hypotension to prevent brain edema and ischemia that may occur with excision of a large arteriovenous malformation.

[Hypothalamic hamartoma with precocious puberty--a case report]

A case of hypothalamic hamartoma with precocious puberty is presented and the literature of reported cases is reviewed. An 8-year-old boy was admitted to our hospital because of precocious puberty and mental retardation. His genital development was Tanner's stage 4 and pubic hair was Tanner's stage 3. Bone age was 11 years. Plain CT showed an isodense mass in the suprasellar cistern which was not enhanced following contrast administration. Metrizamide CT cisternography showed a filling defect in the suprasellar cistern. Endocrinological evaluation revealed high levels of serum luteinizing hormone (LH) and testosterone with a marked response of LH to LH-RH injection. A left frontotemporal craniotomy was performed and the tumor was partially removed. The tumor was gray, firm and well-circumscribed with poor vascularity. Postoperatively, a right oculomotor palsy and transient diabetes insipidus developed. He was discharged ambulatory one month later. Serum LH and testosterone returned to normal and the response of LH to LH-RH injection became normal. Hamartoma was diagnosed on histological examination. Electron micrographic study showed numerous dense granules with approximately 0.1 mu in diameter, in which Judge proved LH-RH by immunofluorescent study in 1977. Our case supports the hypothesis that hypothalamic hamartoma may cause precocious puberty by autonomous secretion of LH-RH and we consider that neurosurgical treatment is recommended.