Treatment of persistent sleep-wake schedule disorders in adolescents with methylcobalamin (vitamin B12).

Two adolescent patients suffering from persistent sleep-wake schedule disorders appear to have responded to treatment with vitamin B12 (methylcobalamin). A 15-year-old girl with delayed sleep phase syndrome (DSPS) and a 17-year-old boy with hypernychthemeral syndrome complained of not being able to attend school despite many trials of medication. The improvement of the sleep-wake rhythm disorders appeared immediately after the administration of high doses (3,000 micrograms/day) of methylcobalamin. Neither patient showed any laboratory or clinical evidence of vitamin B12 deficiency or hypothyroidism (which can cause B12 deficiency). Serum concentrations of vitamin B12 during treatment were in the high range of normal or above normal. The duration of the sleep period of the DSPS patient decreased gradually from 10 hours to 7 hours, and the time of sleep onset advanced from 2 a.m. to midnight. The period of the sleep-wake cycle of the hypernychthemeral patient was 24.6 hours before treatment and 24.0 hours after treatment. The relationship between the circadian basis of these disorders and vitamin B12 and its metabolites is discussed.     

An autopsy case of so-called midline malignant reticulosis followed by extensive dissemination with immunohistochemical evidence for its T cell malignancy

An autopsy case of malignant midline reticulosis (MMR) is reported. The patient, a 42-year-old Japanese male, died after a clinical course of 22 months. Autopsy revealed extensive infiltration of generalized organs by the tumor cells, suggesting that the disease was highly malignant in nature. Staining with monoclonal antibodies against T-cell surface antigens Leu 4 on frozen sections and UCHL1 on paraffin-embedded sections enabled us to examine the phenotype of the tumor cells with good morphological preservation and to verify the T cell nature of the tumor.     

Cross-regional survey of seasonal affective disorders in adults and high-school students in Japan

BACKGROUND: In Asian countries, there is no epidemiological report on seasonal affective disorder (SAD) in different age groups and different geographic regions surveyed at the same time. The aim of this study was to estimate the prevalence rates of SAD and risk factors for SAD in adults and high-school students, with special reference to the difference of winter SAD between northern and southern regions in Japan. METHODS: A total of 3237 high-school students and 4858 workers living in Japan (31.3-43.5 degrees N) responded to this epidemiological survey using Japanese version of the Seasonal Pattern Assessment Questionnaire (SPAQ). RESULTS: The overall prevalence rates of winter SAD (subsyndromal winter SAD) and summer SAD (subsyndromal summer SAD) in high-school students were 0.91(2.21) and 0.81(2.57)%, respectively. In workers, these rates were 0.45(1.16) and 0.43(0.71)%, respectively. Although no regional difference was noted in high-school students with winter seasonal type, the estimated odds ratio of this type for northern workers was nearly 3-fold higher than the southern counterparts. The prevalence rates of each seasonal type were not significantly different between two sexes in both age groups. No clear dependence on latitude was seen with regard to summer SAD in both age groups. LIMITATIONS: The effect of climate on SAD could not be entirely excluded from geophysical factor as indexed by latitude. CONCLUSIONS: SAD was less common in adults than in high-school students. While latitude was a major determinant of winter type in adults, socio-cultural factors or other contributing factors might affect the development of this type in high-school students.     

Selection of appropriate antimicrobial agents to test and report by clinical microbiology laboratories

Clinical microbiology laboratories in Japan have not yet established standards for selecting the most appropriate antimicrobial agents for testing and reporting antimicrobial susceptibility that are comparable to the performance standards of the National Committee for Clinical Laboratory Standards(NCCLS) in the United States of America. Selection of the most appropriate antimicrobial agents for testing and reporting was discussed by a working group(WG) consisting of medical physicians, surgeons, pharmacists, medical technologists and medical microbiologists. The WG agreed on the following basic criteria for the selection of antimicrobial agents: 1) the agent should be useful when screening various resistant bacteria, 2) the agent should serve as a useful guide for physicians and residents when selecting antimicrobial agents, and 3) the agent should be useful for controlling nosocomial infections and resistant bacteria. Clinically isolated microorganisms were classified into 7 groups based on susceptibility to antimicrobial agents. These groups were Staphylococcus spp. or Enterococcus spp., Streptococcus spp. or Haemophilus spp., enterobacteriae, glucose non-fermenting gram positive rods(NFRs), anaerobic bacteria, fungi and mycobacterium. After considering clinical and bacteriological evidence, the WG decided on several antimicrobial agents for testing in clinical microbiology laboratories in Jichi Medical School Hospital. For the NFR group, these were Piperacillin(PIPC), ceftazidime(CAZ), cefepime, imipenem, amikacin and levofloxacin(LVFX). For the enterobacteriae group, these were Amplicillin(ABPC), PIPC, aztreonam, CAZ and LVFX. For the Staphylococcus spp. or Enterococcus spp. group, these were oxacillin, ABPC, vancomycin and gentamicin. We concluded that the most appropriate antimicrobial agent for testing and reporting must be economical and agreed upon at the hospital level, although the ultimate selection must be based on the available clinical and bacteriological evidence.     

The combination of IFN-alpha2 and IFN-alpha8 exhibits synergistic antiproliferative activity on renal cell carcinoma (RCC) cell lines through increased binding affinity for IFNAR-2.

Although there are at least 13 interferon-alpha (IFN-alpha) subtypes in humans, interactions between the subtypes remain unknown. To understand IFN-alpha interactions, we examined the antiproliferative activities and the receptor binding affinities of different combinations of IFN-alpha2 and IFN-alpha8 using six renal cell carcinoma (RCC) cell lines. Although IFN-alpha8 was the more potent subtype, synergistic and antagonistic antiproliferative effects were also observed in certain combinations of IFN-alpha2 and IFN-alpha8. To analyze the interactions between IFN-alpha2 and IFN-alpha8, the receptor-binding kinetics of different combinations of IFN-alpha2 and IFN- alpha8 to the IFN-alpha receptors, IFNAR-1 or IFNAR-2, were measured using a surface plasmon resonance-based biosensor. Unexpectedly, the receptor binding kinetics to IFNAR-2 but not to IFNAR-1 were mutually related to antiproliferative activity and increase in the binding speed (K(a)) for IFNAR-2. Moreover, we observed the increased fluorescence intensity (FI) of biotin-labeled IFN-alpha8 to IFNAR-2 by receptor binding inhibition assay with unlabeled IFN-alpha2 but not the other combinations. These findings indicate that the binding manner of IFN-alpha8 for IFNAR-2 is different from that of IFN-alpha2, suggesting that binding of IFN-alpha8 rather than binding of IFN-alpha2 to IFNAR-2 leads to activation and subsequent antiproliferative activity despite the same antiviral activity in RCC.     

Effect of NMDA receptor antagonist on proliferation of neurospheres from embryonic brain

The N-methyl-D-aspartate (NMDA) receptor, a subtype of ionotropic glutamate receptors, plays an important role in the regulation of neuronal development, learning and memory, and neurodegenerative diseases. NMDA receptor blockade enhances neurogenesis in the hippocampal dentate gyrus in vivo. The effect of NMDA receptor antagonist on proliferation of neural progenitor cells, however, remains to be determined. We investigated changes in the diameter and number of neurospheres derived from the embryonic rat brain after NMDA receptor blockade. Cortical progenitor cells were isolated from gestational day 18 fetal rats according to the Percoll density gradient method. Cultured spheres expressed neural progenitor markers, musashi-1 and nestin. Immunohistochemical analysis demonstrated that cells in Dulbecco's modified Eagle medium/F12 containing 1% fetal bovine serum on day 8 differentiated to MAP-2-positive neurons and GFAP-positive astrocytes. The expression of NR1 and NR2B subunits of the NMDA receptor in neurospheres was detected. Neither brief nor sustained exposure to NMDA altered the diameter and number of neurospheres. Brief exposure to 30 μM MK-801, an NMDA receptor antagonist, decreased the diameter of neurospheres. Sustained exposure to 30 μM MK-801 decreased the diameter and number of neurospheres. Our results provide evidence that MK-801 directly decreased proliferation of neural progenitor cells.     

N-Glycosylation contributes to the limited cross-reactivity between hemagglutinin neuraminidase proteins of human parainfluenza virus type 4A and 4B

cDNAs encoding human parainfluenza virus type 4B (hPIV-4B) hemagglutinin neuraminidase (HN) protein were cloned and the nucleotide sequences were determined. A high degree of identity (81.4%) was observed between the nucleotide sequences of hPIV-4A and -4B HN proteins, and an 87.3% identity was found between the deduced amino acid sequences. This degree of identity is considered to be greater than immunological similarity between hPIV-4A and -4B HN proteins determined using monoclonal antibodies. To elucidate the causes of the antigenic difference between HN proteins of hPIV-4A and -4B, we constructed three cDNAs of hPIV-4B HN whose potential N-glycosylation sites were partially or completely the same as in hPIV-4A HN cDNA. We compared the antigenicity of the expressed wild-type and mutant proteins, and found that the antigenicities of the mutant hPIV-4B HN proteins were more similar to the hPIV-4A HN protein than to the non-mutant hPIV-4B HN protein. This study indicated that the antigenic diversity between hPIV-4A and -4B was partly caused by deletion or creation of glycosylation sites, showing that the point mutations resulting in deletion or creation of glycosylation sites is one of the initial steps leading to the division of virus into subtypes. Received: 21 January 2000     

An autopsy case of idiopathic enlargement of the right atrium, and a review of the literature

A 69-year-old man in whom idiopathic enlargement of the right atrium was revealed at autopsy is described. The patient had had cardiomegaly of at least 19 years' duration prior to his death, even though cardiac symptoms were absent. Cause of death was pancreatic carcinoma. Postmortem examination revealed marked and diffuse dilatation of the right atrium and moderate dilatation of the left atrium. Measurement of the cardiac chambers showed that the right and left atria were 7.6 and 4.7 times as large as those of normal hearts, respectively. The volume of either ventricle was about twice the normal value. Histologically, widespread cardiac muscular degeneration and necrosis, diffuse fibrosis, and focal lymphocytic infiltration were found in the right atrium and also, to a lesser degree, in the left atrium. Such pathologic changes were not found in either of the ventricles. The etiology of these muscular changes, which might have been related to atrial enlargement, was unclear. The present case was thought to be consistent with idiopathic enlargement of the right atrium, and a brief review of the literature is given.     

Imaging mitochondrial redox environment and oxidative stress using a redox-sensitive fluorescent protein.

Redox-sensitive green fluorescent protein (roGFP) is a fluorescent protein in which two cysteines are placed adjacently in the barrel structure. Disulfide formation (oxidation) increases the absorption at short wavelengths (410 nm) at the expense of absorption at longer wavelengths (490 nm). The fluorescence ratio indicates reduction/oxidation, i.e., the redox potential at specific cellular locations.