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H Sekine

Publications and source records attributed to H Sekine.

At least 73 records · Page 4Linked to original sources
PubMed1996

Characteristics of behavioural stimulant effect of N-cyanomethylmethamphetamine, a main product of smoking methamphetamine mixed with tobacco: evaluation by ambulatory activity in mice.

N-cyanomethylmethamphetamine is main product of smoking methamphetamine HCl (CAS code value: 537-46-2, molar mass: 185.70 g/mol) mixed with tobacco, and has a central stimulant action. The aims of this study were to assess in terms of ambulation in mice whether repeated administration of N-cyanomethylmethamphetamine HCl (molar mass: 211.70 g/mol) induced sensitization to its central stimulant effect, and whether there were cross-sensitization from N-cyanomethylmethamphetamine HCl to methamphetamine HCl, and from methamphetamine HCl to N-cyanomethylmethamphetamine HCl. N-cyanomethylmethamphetamine HCl 14.2 and 47.2 mumol/kg subcutaneously dose-dependently accelerated ambulation of mice. Five administrations at 3 day intervals caused sensitization, the activity counts in the fifth administration being approximately 2.6 and 1.6 times, higher respectively, than those in the first administration. Furthermore, the mice repeatedly given 14.2 and 47.2 mumol/kg N-cyanomethylmethamphetamine HCl exhibited cross-sensitization to methamphetamine HCl (10.8 mumol/kg subcutaneously). Whereas 1.4 and 4.7 mumol/kg N-cyanomethylmethamphetamine HCl did not induce significant acceleration of the ambulation throughout the 5 repeated administrations, nor cross-sensitization to methamphetamine HCl. On the other hand, the 5 repeated administrations of methamphetamine HCl (10.8 mumol/kg) also caused sensitization to its ambulation-increasing effect, and the activity count in the fifth administration attained approximately 2.0 times higher than that in the first administration. The mice given methamphetamine HCl demonstrated cross-sensitization to 1.42-14.2 mumol/kg N-cyanomethylmethamphetamine HCl. Haloperidol (CAS code value: 52-86-8, molar mass: 375.88 g/mol; 0.027-0.80 mumol/kg subcutaneously) dose-dependently reduced the ambulation-increasing effects of N-cyanomethylmethamphetamine HCl and methamphetamine HCl in the drug-naive, and N-cyanomethylmethamphetamine HCl- and methamphetamine HCl-sensitized mice. These dose-effect relationships were similar between groups. The present results suggest that N-cyanomethylmethamphetamine HCl has a behavioural stimulant effect almost similar to that of methamphetamine HCl.

Amphetamines↗
PubMed1996

Extragonadal germ cell tumor followed by metachronous testicular tumor. A case report.

We here present a patient with an extragonadal germ cell tumor followed by a metachronous testicular tumor 7 years later. The histological findings of the extragonadal tumor and the subsequent testicular tumor were quite different; the former was of a mixed type with teratoma, embryonal carcinoma and yolk sac tumor, and the latter a pure seminoma. Such a long clinical time lag as 7 years and the histological differences between the two tumors suggest that they occurred independently. To our knowledge, this may be the first case report in the literature, in which a testicular tumor occurred metachronously after extragonadal tumor extirpation.

Adolescent↗
PubMed1996

Abuse of smoking methamphetamine mixed with tobacco. V. Plasma metabolites of N-cyanomethylmethamphetamine, a pyrolysis product formed by smoking methamphetamine in tobacco, and the species difference between mouse and rat.

N-Cyanomethylmethamphetamine (CMMA), N-formylmethamphetamine (FMA) and methamphetamine (MA) were given intraperitoneally to mouse and rat in doses of 3 mg/kg. The major metabolites of CMMA, FMA and MA in plasma were determined at short intervals after administration by GC-MS to obtain the area under the concentration-time curve (AUC). Regarding the plasma concentration of FMA after CMMA administration, a definite species difference was observed between mouse and rat. In rats given CMMA, FMA was the major component, followed by MA, amphetamine (AP), CMMA and N-formylamphetamine (FAP). In mice given CMMA, MA was a major component, followed by AP, FMA, CMMA and FAP. However, it was demonstrated that MA is also non-enzymatically produced from CMMA in plasma. Following FMA administration to rats, FMA was the major component in the plasma, showing the largest AUC value of the four metabolites, FMA, FAP, MA and AP. Following FMA administration to mice, MA showed the largest AUC value, followed by FMA, FAP and AP which were present at low levels even 5 min after injection and were scarcely detectable at 60 min. These results suggest two main mechanisms involved in the metabolism of the N-cyanomethyl group, one of which is the formation of MA by elimination of cyanoformaldehyde from N-alpha-hydroxylated CMMA and the other which is the formation of FMA by elimination of hydrogen cyanide from N-alpha-hydroxylated CMMA. The formation of FMA from CMMA was the predominant pathway in rats but not in mice.

Amphetamines↗
PubMed1996

[Gastric mucosal atrophy and prevalence of Helicobacter pylori in reflux esophagitis of the elderly].

This study is aimed at a role of Helicobacter pylori (HP) infection in reflux esophagitis of the elderly. 46 patients with reflux esophagitis aged at older than 60 years are selected for this study with informed consent. 43 patients without reflux esophagitis, peptic ulcer, and gastric cancer are used as a control group. In reflux esophagitis, gastric mucosal atrophy is judged as closed type of endoscopic findings in all cases. In control, 27 of 43 patients were judged as open type. Serum pepsinogen I, II ratio is 4.73 +/- 1.28 which is higher significantly than 3.39 +/- 1.69 in control. Serological positive rate of HP antibody is 39.1% in reflux esophagitis. This rate is significantly lower than 62.7% in control. In conclusion, low frequency of chronic HP infection protects gastric mucosa from atrophy, and keeps secretion of gastric acid, resulting in reflux esophagitis of the elderly accompanied with various abnormal esophago-gastric functions.

Aged↗
PubMed1996

[Methodological study of 13C-urea breath test for detection of Helicobacter pylori infection].

In this study, we investigate simple breath test for detection of Helicobacter pylori (HP) infection using 13C-urea. Thirty-nine patients (30 were HP positive, 9 were HP negative) were given three different doses (50, 100 and 150 mg) of 13C-urea at fasting, and keep sitting after mouth washing with water. Breath samples were taken before and 10, 20, 30, 45, and 60 minutes after urea administration. More than 100mg of 13C-urea was necessary for correct diagnosis of HP infection, because 2 HP positive cases were not detected by 50mg 13C-urea administration. In cases with patchy distribution of HP in the stomach, it may be necessary to change the posture to distribute urea within the whole stomach. In most of HP positive cases, peak delta 13CO2 were obtained within 30 minutes, but one HP negative case showed high delta 13CO2 at 10 minutes, which was probably caused by urease activity in the mouth. So it is appropriate to take breath sample at 20 minutes after urea administration. In this study, cut-off value for a positive test can be setted between 4 to 7 delta/1000, it is necessary to investigate much more cases to set exact cut-off value.

Adult↗
PubMed1996

[Therapeutic ratio of fractionated high-dose-rate against continuous low-dose-rate brachytherapy analyzed by simulation model].

In order to establish the standard schedule of 192Ir-HDR brachytherapy, it is necessary to determine the optimal time-dose-fractionation. A new simulation model was used to determine the optimal schedule. This model, which is based on the LQ-model, includes the effect of incomplete repair between fractionations. The fraction surviving after irradiation is expressed as log (surviving fraction) = n (-alpha x -beta x2)-n beta x2 hn (theta), and the change in fractionation will influence the value of hn (theta). From analysis of this model, the therapeutic ratio will approach one if two fractionations (6-hour and 18-hour intervals) or three fractionations (4-hour, 4-hour and 16-hour intervals) in a day are carried out for 6 days. This simulation model will provide an optimal treatment schedule for tumor control, for example, two daily fractionations of 4.6Gy with 6-hour intervals between the daily fractionations (and 18 hours to the first fractionations of the next day), 12 fractionations to 55.2Gy in 6 days or three daily fractionations of 3.3Gy with a 4-hour interval between the daily fractionations (and 16 hours to the first fractionations of the next day), 18 fractionations to 59.4Gy in 6 days. Further clinical study should be carried out to confirm this simulation.

Brachytherapy↗
PubMed1996

[Imaging of strontium-89 uptake with bremsstrahlung using NaI scintillation camera].

Strontium-89 chloride is widely available in the U.S. and Europe for patients afflicted by bone metastasis associated with pain. 89Sr is a pure beta-emitter and it is thought to be difficult to estimate its distribution externally. We tried to image the distribution of 89Sr uptake with bremsstrahlung from beta-minus decay of 89Sr by using Nal scintillation camera. Pronounced 89Sr depositions in the bone metastatic sites were imaged in the energy windows from 50 keV to 150 keV bremsstrahlung. The distribution of these depositions corresponded to 99mTc-HMDP image may be suspected to the effectiveness of this therapy. The identification of 89Sr distribution might be useful in evaluating the bone marrow radiation dose too.

Aged↗
PubMed1996

[Preliminary screening for antiviral AIDS drugs. VII. Report for fiscal year 1994].

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 246 samples of different origin tested, six were shown to inhibit the growth of HIV in vitro. Two of the positive samples have hopeful signs, as the ranges of effective doses are wider than those of most of positive samples which had been found by us.

Anti-HIV Agents↗
PubMed1996

Periarticular ectopic calcinosis probably due to 1 alpha-OH-vitamin D3 therapy, and successful treatment with bisphosphonate compound in a patient with systemic lupus erythematosus.

We describe the case of a 25-year-old woman who developed soft tissue ectopic nephritis. Ectopic calcinosis rarely occurs in systemic lupus erythematosus (SLE) patients. This is the first detailed case report of metastatic ectopic calcinosis, one of two categories of ectopic calcinosis, probably due to 1 alpha-OH-vitamin D3 therapy. We administered disodium 3-amino-1-hydroxypropylidene-1, 1-bisphosphonate pentahydrate, a second-generation bisphosphonate, to decrease the patient's serum calcium level, and subsequently observed a dramatic decrease in severity of the ectopic calcinosis along with decreases in both the serum calcium level and the (serum calcium level)x(serum phosphate level) index. We suggest that 1 alpha-OH vitamin D3 should be used in cases of lupus nephritis with great caution.

Adult↗
PubMed1996

Functioning survival rate of fixtures and superstructures of osseointegrated implants: ten years of progress in Tokyo Dental College Hospital (second report).

Osseointegrated implant bridges (OIB) have shown excellent results in the majority of cases. Since 1983, 1,022 fixtures has been applied to 241 superstructures in Tokyo Dental College Hospital. The aim of present study was to examine their functioning survival rate during recent ten years. The functioning survival rate of the superstructure of OIB has been almost 100% in both maxilla and mandible. Although 13.0% of these fixtures had to be removed in maxillary complete cases, only 3.3% of fixtures were removed in other cases. In maxillary complete cases, the functioning survival rate of OIB fixtures gradually decreases from 91% to 74% (91%, less than 3 years; 84%, between 3 and 7 years; 74%, more than 7 years), but it remained at about 97% for all periods in other cases. Apparently, the functioning survival rate of OIB fixture is generally determined within the period of one year, so almost the same rate is maintained thereafter. It is suggested that if more fixture numbers in the superstructure were applied to maxillary complete cases, the functional survival rate might improve.

Adolescent↗
PubMed1995

Systemic lupus erythematosus with necrotizing vasculitis and upregulated expression of VLA-4 antigen.

We report on a patient (S.A.), with well-defined SLE who developed a perforation of the ileum due to pathologically confirmed necrotizing vasculitis. No anti-DNA antibody was detected at the ileal perforation, and the serum complement level was normal. These findings raise the alternative possibility of a cell-mediated immune mechanism as a cause of necrotizing vasculitis. Upregulated expression and function of VLA-4 antigen on peripheral blood T cells were observed, suggesting that T cells with VLA-4 antigen may participate in the onset and/or perpetuation of vascular inflammation.

Adult↗
PubMed1995

[Studies on maternal transmission of HIV-1].

To investigate HIV-1 transmission from mother to child, samples taken from 3 HIV-1 sero-positive pregnant mothers, 3 children born by caesareans from their mothers and therapeutic abortion from 2 HIV-1 sero-positive mothers were tested for HIV-1 antibody by westernblot, p24 antigen by antigen captured ELISA, proviral DNA by Nested-PCR and isolation of HIV-1 virus from peripheral blood, cord blood, amniotic fluid and placenta. HIV-1 proviral DNA was detected in the peripheral blood of all mothers, but p24 antigen and virus isolation were not detected. None of the HIV-1 markers, except for antibody, was detected in the samples from their children and placenta. These facts strongly suggest that there was no HIV-1 transmission from mother to child.

AIDS Serodiagnosis↗
PubMed1995

The inhibitory effect of the crude extract from a seaweed of Dygenea simplex C. Agardh on the in vitro cytopathic activity of HIV-1 and it's antigen production.

The crude water extract (NS-1) from a seaweed (Digenea simplex C. Agardh Rhodomelaceae) exhibited anti-human immunodeficiency virus (HIV)-1 activity in vitro. The inhibitory effect of the extract on the cytopathic activity of HIV-1 and it's antigen production was examined using a microplate method, immunofluorescent assay, and an HIV antigen detection kit (Abbott). NS-1 inhibited both the cytopathic effect of HIV-1 to MT-4 cells and the giant cell formation of Molt-4 cells infected with HIV-1.

Antiviral Agents↗
PubMed1995

Abuse of smoking methamphetamine mixed with tobacco. III. Urinary metabolites of N-cyanomethylmethamphetamine, a pyrolysis product formed by smoking methamphetamine in tobacco, and species difference in its metabolism between rat and mouse.

1. N-cyanomethylmethamphetamine (CMMA) or methamphetamine (MA) was given intraperitoneally to rat and mouse (1, 3, 10 mg/kg). The basic urinary metabolites of CMMA were determined by mass spectrometry (MS) and compared with those of MA. 2. N-formylmethamphetamine (FMA), a specific metabolite of CMMA, was found in both rat and mouse urine. However, the dose percentage of FMA excreted in mouse urine was less than one-quarter of that in rat urine. 3. No CMMA was detected in rat or mouse urine collected within 72 h after dosing. All other basic metabolites of CMMA except FMA, i.e. MA, amphetamine (AP), p-hydroxymethamphetamine (OHMA) and p-hydroxyamphetamine (OHAP), were the same as those of MA in both species. 4. The excretion pattern of the urinary metabolites of CMMA was similar to that of MA except FMA in both species, though the amount of each metabolite of MA administration was larger than that of CMMA administration. However, in urinary excretion of FMA and hydroxylated metabolites, definite species differences were observed between rat and mouse. 5. A trace amount of FMA was identified in the urine of an abuser who had smoked MA with tobacco.

Amphetamines↗
PubMed1995

White matter changes caused by chronic solvent abuse.

PURPOSE: To examine the brain damage of solvent abusers in Japan, where pure industrial toluene is frequently abused. METHODS: Twenty solvent abusers 17 to 33 years of age with 7.2 +/- 4.0 years of abuse were examined with a 1.5-T MR imaging system. RESULTS: White matter hyperintensities in cerebrum, brain stem, and cerebellum on T2-weighted images were found in seven cases. The extent of white matter change was most clearly shown on proton density-weighted images. The patients with restricted white matter change and intermediate white matter change showed white matter hyperintensities in the brain stem and cerebellum on T2-weighted images, in some cases, with additional hypointensities in the corresponding T1-weighted images. These patients had mainly abused pure toluene. The patients with diffuse white matter change showed obvious brain atrophy, including hippocampal atrophy and thinning of the corpus callosum. These patients had mainly abused lacquer thinner. CONCLUSION: There are some patients with restricted but severe enough change to cause the neurologic symptoms in specific regions, such as the brain stem and/or cerebellum, before the brain atrophy becomes apparent. This suggests that the restricted white matter change represents not only an early change of diffuse white matter change, but at least in some cases also represents a qualitatively different change than that of diffuse white matter change. We suggest that pure toluene has a possible relation to this qualitative difference.

Adolescent↗