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S Shida

Publications and source records attributed to S Shida.

53 records · Page 3Linked to original sources
PubMed1983

Variation of 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2 levels in human plasma obtained from 758 Japanese healthy subjects.

Plasma levels of 25-hydroxyvitamin D3 (25-OH-D3) and 25-hydroxyvitamin D2 (25-OH-D2) in 758 Japanese healthy subjects (most of them adults) were determined by a high-performance liquid chromatographic method previously reported (6) and the following results were obtained: The mean and standard deviation (M +/- SD) of the assayed values of 25-OH-D (sum of 25-OH-D3 and 25-OH-D2) was 23.8 +/- 10.1 ng/ml. 25-OH-D3 was detected in all the samples and the M +/- SD was 23.0 +/- 10.1 ng/ml. The plasma levels clearly showed the seasonal variation that the levels in summer were significantly higher than those in winter. Moreover, the plasma levels were significantly correlated with the amounts of UV light in solar radiation. These results strongly suggested that 25-OH-D3 in plasma mainly originated from endogenous vitamin D3 formed by photo-conversion of 7-dehydrocholesterol in skin. 25-OH-D2 was detected only in 18.3% of the plasma samples and the M +/- SD in the detected samples was 4.4 +/- 2.9 ng/ml which was much lower than those of 25-OH-D3. The results suggested that few healthy Japanese are taking daily exogenous vitamin D2 from multivitamin preparations or others. The M +/- SD values of 25-OH-D3 plasma levels in men and women were 26.2 +/- 10.4 and 19.3 +/- 8.0 ng/ml, respectively. The formers were significantly higher than the latters. The results were thought to be due to the reason that men might be outdoors for longer periods than women. When age variation of plasma 25-OH-D3 levels was examined, the levels in the twenties were significantly lower than the other generations. This was confirmed to be due to the low values observed in the female twenties group, but the detailed reason is unclear at the present time. When 4 healthy volunteers were orally administered 400 I.U./day of vitamin D2 every day for 8 weeks, maximum levels (average: 11.5 ng/ml) were observed at the 8 weeks and the levels gradually decreased after stopping the administration. The results suggested that the half life of 25-OH-D2 in plasma might be 4-5 weeks.

25-Hydroxyvitamin D 2↗
PubMed1981

A method for simultaneous determination of 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 in human plasma by using two steps of high-performance liquid chromatography.

A method for simultaneous determination of 25-hydroxyvitamin D2 (25-OH-D2) and 25-hydroxyvitamin D3 (25-OH-D3) in human plasma has been developed by using two steps of high-performance liquid chromatography (HPLC). Lipids extracted from 0.51 ml of human plasma were first subjected to the preparative HPLC using a Nucleosil 5C18 column (reversed-phase type) and a 25-OH-D fraction containing 25-OH-D2 and 25-OH-D3 was separated. The separated fraction was subsequently subjected to the analytical HPLC using a Zorbax SIL column (straight-phase type). Since the peaks corresponding to 25-OH-D2 and 25-OH-D3 were clearly separated from one another on the chromatogram of the analytical HPLC, the metabolites could be simultaneously determined by estimating the respective peak heights. When the fractions corresponding to the respective peaks were separately collected by repeatedly applying rather large quantities of human plasma and were subjected to gas chromatography-mass spectrometry (GC-MS), they were identified as containing 25-OH-D2 and 25-OH-D3, respectively. The proposed method was applied to plasma samples of human adults taking 400 I.U./day of vitamin D2 for 8 weeks and the values were 22.5 +/- 8.1 ng/ml for 25-OH-D3 and 11.5 +/- 1.8 ng/ml for 25-OH-D2 (mean +/- S.D.), respectively.

25-Hydroxyvitamin D 2↗
PubMedDate not supplied

Cell preparation methods and criteria for sample adequacy. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: Cell Preparation Methods Standardized fixation and optimal staining Sampling of cervix, sampling error, homogenization of sample, subsampling Assessment of liquid-based preparations: efficacy and economic impact Training and transitional procedures before full implementation of new technologies Criteria for Sample Adequacy Clinician responsibility for collecting and providing representative sample to laboratory Collection instruments, number of slides Cellular content of samples: evidence of transformation zone (TZ) sampling, number of squamous cells present, obscuring factors Screening issues CONSENSUS POSITION The conventional cervical smear remains the standard method of cervical cancer screening but has limitations in individual test sensitivity and specificity. Sample takers should: (1) receive appropriate training in sample collection, (2) be held responsible for providing the laboratory with appropriate samples, and (3) have their performance monitored. The instruments used for sampling should collect cells from both the ectocervix and endocervix; optimally, TZ sampling, represented by the presence of endocervical or squamous metaplastic cells, should be identifiable in samples other than atrophic specimens. The adequacy of a specimen (as judged microscopically) does not guarantee that it is representative of the cervix. Each cytology report should include a comment on cellular content/adequacy of the specimen. Liquid-based preparations may overcome many of the inherent problems with the conventional cervical smear. ONGOING ISSUES: We need further data on the cost-effectiveness of making two slides from cervical specimens and/or using two samplers rather than a single one. Do we have enough information to make recommendations as to the appropriate type of sampler to be used in particular situations, such as routine screening? What is the best method of screening for/detecting endocervical glandular neoplasia? How are such terms as unsatisfactory and inadequate defined in cervical cytology classifications other than the Bethesda System? What number and types of epithelial cells should be present (visualized) in a cervical smear or liquid-based preparation for it to be considered adequate? Do we need to have evidence of TZ sampling in specimens taken during the follow-up period after treatment of squamous intraepithelial lesion or after detection of endocervical glandular neoplasia? What criteria for obscuring factors, such as blood and inflammation, should be used in assessing adequacy? Cost-benefit analyses of utilizing liquid-based preparations are needed. Should we inform women about the technical details of the test methods available or chosen by the laboratory? Are women in a position to decide which method is the most appropriate to assess their cervical scrape sample? We need to obtain more information about the properties of proprietary liquid fixative/transport media with respect to inactivation of viral pathogens, tuberculosis and other bacterial pathogens and suitability for immunobiologic and molecular tests, etc. We need to obtain more information on the use of stoichiometric stains and the limitations of Papanicolaou stain for image analysis systems. The use of liquid-based preparations for nongynecologic cytopathology and ancillary tests must be considered, including criteria for adequacy. We need to obtain more information on the time required for and best methods of training experienced cytotechnologists to become competent at assessing liquid-based cervical preparations.

Cell Biology↗