Biomedical subjects
Publications and source records attributed to C Kanazawa.
We report a case of lipoblastoma in a 6-month-old girl with a new chromosomal aberration, 46, XX, der (2) add (2) (p23) del (2) (q33), add (8) (q1?). In addition to the patient's age and pathological features, aberration of long arm of chromosome 8 in lipoblastoma can assist the differential diagnosis from myxoid or well differentiated liposarcoma.
The Gly71Arg mutation of the hepatic bilirubin UDP glucuronosyl-transferase (B-UGT) gene associated with Gilbert syndrome prevails among Japanese and its gene frequency is 0.13. Among 20 patients with acute leukaemia, 4 patients showed intermittent unconjugated hyperbilirubinaemia during the course of combined chemotherapy. The Gly71Arg mutation was detected in all 4 patients with hyperbilirubinaemia, but was not found in 16 patients without hyperbilirubinaemia. Two of them were heterozygotes and one was a homozygote for the Gly71Arg mutation, and the other was a compound heterozygote of the Gly71Arg mutation and TA insertion mutation in the TATA box of the B-UGT gene. In addition to the complications leading to hyperbilirubinaemia, including liver damage due to drugs, viral infections or tumour cell infiltrations and alloimmune haemolysis, carrier status for the Gly71Arg mutation should be considered in a patient with leukaemia showing intermittent hyperbilirubinaemia during the course of chemotherapy, especially among Japanese, Koreans and Chinese owing to its prevalence in those populations.
We report here a 15-year-old boy with an intraabdominal desmoplastic small round cell tumor (DSRCT). Cytogenetic analysis of the tumor cells showed the chromosomal translocation (11;22). Reverse-transcriptase polymerase chain reaction and sequencing analysis revealed a chimeric transcriptional message of the EWS gene exon 10 fused to the WT1 gene exon 8. The typical chimeric transcript seen in DSRCT is an in-frame fusion of EWS exon 7 to WT1 exon 8. The tumor in this case had a novel and longer chimeric transcript, which should be a potent transcription factor. Genetic analysis is a very powerful and specific aid in the differential diagnosis of small round cell tumors.
BACKGROUND: The function of CD48, one of the pan leukocyte cell surface antigens, is not yet well understood. CD48 was recently shown to enhance the CD40-mediated activating signal to B lymphocytes. As CD48 is one of the activation antigens of monocytes, neutrophils and lymphocytes, a change of its expression on the cells could be expected in infectious diseases. METHODS AND RESULTS: Leukocytes from 27 healthy controls and 97 patients with various infectious diseases were stained with anti CD48 antibody and analyzed by flow cytometry. On monocytes and neutrophils, the CD48 expression was increased in all of the patients with varicella, measles, rubella, infectious mononucleosis, streptococcus tonsillitis, sepsis and appendicitis. On lymphocytes, a significant increase of CD48 was also detected in the patients with the same diseases, except those with sepsis or appendicitis. The normalization of increased CD48 expression was confirmed on monocytes at the convalescent phase. CONCLUSION: These data suggest that CD48 expression on leukocytes reflects the disease activity of infectious diseases, especially of viral infections.
Chromosomal aberrations involving 8q11.2 have been reported in lipoblastoma. We report here a case of lipoblastoma with new chromosomal aberration. 46,XX,ins(8;6)(q11.2;q13q27). Cytogenetic analysis would facilitate the clinical differentiation between myxoid liposarcoma and the pathologically similar lipoblastoma and the identification of genetic loci related to cellular growth.
We previously investigated the role of the Lys108 residue of ribonuclease (RNase) Rh from Rhizopus niveus, and suggested that Lys108 probably acts to stabilize the pentacovalent intermediate, and that an Arg residue could replace the role of Lys108. In RNase Le2 from Lentinus edodes, a homologous enzyme of RNase Rh, Lys108 is replaced by Thr. In this paper, the enzymatic properties of a K108T mutant and its analogous enzyme, K108S, were investigated to determine the effect of Thr and its analog, Ser at the 108th position on enzyme activity. The enzymatic properties of these mutant enzymes were compared with those of other mutant enzymes at this position (K108M, K108A, K108L). The results showed that Thr and Ser could replace Lys108 but resulted in only 2-20% of the activity of the native enzyme depending on the substrates used.
We studied a 3.5-year-old Japanese boy with growth retardation, alopecia, pseudoanodontia, and bilateral papilledema. He was born of nonconsanguineous parents, but his paternal grandparents were related. From his characteristic physical manifestations, we diagnosed him as the first known case of GAPO syndrome in Japan and perhaps in the Mongoloid race. Our case had prominent dilatation of scalp veins and an audible intracranial bruit. Cranial angiography documented a narrowing of the sigmoid sinuses, with no flow to either jugular vein. We discuss here the relationships between optic atrophy and intracranial vascular changes in this syndrome.
We report a 1-year and 9-month old girl with a pachygyria in the left cerebral hemisphere who showed intractable seizures mimicking severe myoclonic epilepsy in infancy (SMEI) treated with TRH-T. The patient has been admitted to our department 3 times and then treated with intramuscular TRH-T (0.5-1.0 mg daily) successfully. Seizures had been controlled with TRH-T in 21, 10 and 5 days, and thereafter ad-on therapy with peroral TRH-T (1-4 mg daily) has been continued. The drop of plasma prolactin level after TRH-T treatment suggests a possible participation of the inhibitory action of dopaminergic neurons in seizure control. Pachygyria is known to have microdysgenesis of the cerebral cortex, which can be the epileptic focus of the case. The TRH-T can be beneficial in the treatment of intractable seizures mimicking SMEI seen in patients with pacygyria.
Non-polio enteroviruses are currently the most common agents of the central nervous system viral infection, and are the major causes especially in patients with aseptic meningitis. The practical problems with enterovirus meningitis revealed from the investigation of our patients are as follows. (1) The triad of symptoms of meningitis (fever, headache, vomiting) were seen only in 50% of the older children affected. The only manifestation of neonates with aseptic meningitis was fever. (2) In more than half of the patients, the cerebrospinal fluid showed polymorphonuclear predominance within 3 days from the onset. (3) The causal viruses were isolated frequently (70%) from the cerebrospinal fluid of the children with aseptic meningitis. (4) The patients more than 1 year of age had no sequela clinically. Among neonates and early infants, transient abnormalities of brain CT findings were seen in 40% and delayed speech in 30%. Their prognosis should be investigated more precisely.
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A single intravenous dose of 2 g of cefpiramide (CPM) was administered prophylactically to 11 patients at 30, 60, 120, or 180 minutes before hip surgery. Peak concentrations in different tissues of CPM were observed in 30 minutes after intravenous injection. Mean concentrations of CPM were 246.0 micrograms/ml in peripheral blood, 298.5 micrograms/ml in bone marrow blood and 77.5 micrograms/g in cancellous bone at 30 minutes after administration. Half-lives of CPM were 152 minutes in peripheral blood and 105 minutes in bone marrow blood. The concentrations of CPM observed in the above study were higher and its retention longer than expected values.
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Incubation of hepatocarcinogenic aminoazo dye, o-aminoazotoluene (OAT) with rat liver microsomes together with NADPH and NADH yielded N-hydroxy-OAT (I), 4'-hydroxy-OAT (II) and a smaller amount of 2'-hydroxymethyl-3-methyl-4-aminoazobenzene (III). As an artifact 4,4'-bis(o-tolylazo)-2,2' -dimethylazoxybenzene (IV) was also detected in a small quantity. The mutagenicities of these metabolites were assayed by using Salmonella typhimurium TA98 and TA100 together with S-9 prepared from the livers of rats treated with polychlorinated biphenyl mixture (PCB). OAT and III were strongly mutagenic, but only when S-9 was present. In contrast, I was a strong mutagen regardless of the presence or absence of S-9. II and IV were non-mutagenic. The yields of I, II and III from OAT were pronouncedly reduced by addition of cytochrome P-450 inhibitors, especially by a cytochrome P-448 inhibitor 7,8-benzoflavone. Mutagenesis by OAT was also inhibited by addition of 7,8-benzoflavone. Activation of OAT for mutagenesis was enhanced by pretreatment of the donor rats with PCB or 3-methyl-cholanthrene and to a much lesser extent by phenobarbital. These findings suggest that N-hydroxylation of OAT mainly proceeds via catalysis by cytochrome P-448 and that this process is an obligatory step for the activation of OAT. Synthetic methods for the preparation of new azo compounds such as I, IV and 2',3-dimethyl-4-nitrosoazobenzene are described.
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Effects of various doses of betamethasone on cold induced brain edema were studied in rats by RISA extravasation counting technique. Betamethasone was given in a single injection two hours prior to production of the lesion. Only limited doses were effective in preventing edema. There seem to be no beneficial effects in doses over 1 mg up to 100 mg/kg of body weight, the optimal dosage being estimated to be around 0.5 mg/kg. This result might indicate that the usual loading dose of 10 mg/kg in man is rather small for preventing brain edema most efficiently.
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We experienced a rare and peculiar eye movement in a comatose patient with ruptured intracranial aneurysm. The patient's eyes moved quickly and irregulary from one extreme position to the other with whirling and bounding components. Such abnormal eye movement occasionally halted, but abruptly reappeared. We named this abnormal eye movement which had never been reported before, "ping-pong eye movement". Neuropathological study revealed a subarachnoid hemorrhage and the diffuse infarction in the right remporal lobe, and a smal clot in the fourth ventricle without specific findings in the brainstem and the cerebellum. Consideration was made that the hemorrhage in the fourth ventricle resulted in a hyper-irritable state in the fastigial nuclei, from which the abnormal discharges were driven to the reticular formation, the vestibular nuclei, the MLF, and the oculomotor complexes. We conclude that this "ping-pong" ball eye movement" might be the appearance of epilepsy in the eyes, due to the epileptogenic focus of the fastigial nuclei.
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