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Biomedical subjects

S Ishida

Publications and source records attributed to S Ishida.

At least 307 records · Page 17Linked to original sources

Studies in meconium. An approach to screening tests to detect cystic fibrosis.

Screening for cystic fibrosis (CF) in newborns is desirable, and efforts should continue in establishing a system of easily available, reliable, simple, and inexpensive tests. In addition to the Boehringer-Mannheim (BM) test for the detection of albumin, we propose the assay for lactase and beta-D-fucosidase in meconium. These latter two enzymes are present in the meconium of babies with CF and absent in meconium of most healthy babies. In a mass screening program for CF involving 20,182 specimens of meconium using only the BM strip, we found 46 positive results. Twenty-nine specimens came from infants with CF, six of whom had meconium ileus. Seventeen specimens yielded false-positive results by the BM test. Eleven of these would have been excluded by the addition of the lactase and beta-D-fucoside assay, thus reducing the false-positive test results by nearly 61%. In a comparative study of the three methods, the lactase and beta-D-fucosidase yielded 1.2% false-positives when examined independently. Performance of these two assays may allow greater specificity in diagnosis when used in addition to the BM test.

Albumins↗

Passive hemagglutination and hemolysis tests for the detection of anti-DNA antibody.

Passive hemagglutination (PHA) and hemolysis (PHL) tests using chromium chloride-treated sheep red blood cells were developed to detect and measure the anti-DNA antibodies. Sonication of native DNA was found to prevent the incidence of non-specific agglutination. Sheep red cells were coated with double-stranded DNA (dsDNA) which had been sonicated and treated with nuclease S1 to digest the single-stranded regions in the DNA. The specificities for dsDNA-coated cells were checked by inhibition studies in PHA test and plaque assay. In clinical studies fairly close correlations were found between the antibodies to DNA and the activity of the disease in patients with systemic lupus erythematosus (SLE). Complement-fixing antibodies were detected in most of SLE patients with active lupus nephritis, but rarely in those in remission. Anticomplementary activity seemed to be negligible in PHL test. These tests are simple and may be useful to the diagnosis and the management of SLE.

Animals↗

Differential display of hippocampal and amygdaloid influences on hypothalamic evoked potentials.

Adult female rabbits with bipolar electrodes chronically implanted in the brain were employed to study the changes of the evoked potentials (EP) in the medial basal hypothalamus including the median eminence (ME), elicited by single hippocampal (HPC) or amygdaloid (AMYG) stimulus during EEG afterdischarge induced by electrical stimulation of the lattter two areas. In HPC seizures, the ME-EP from the HPC stimulation was extensively influenced in amplitude and peak-latency, the former decreased and the latter lengthened remarkably. On the other hand, the ME-EP from the AMYG stimulation did not show any noticeable changes either in amplitude or in peak-latency. During an AMYG seizure, the ME-EP from either the HPC or AMYG stimulation did not show any significant changes in amplitude or peak-latency. The results suggest that electrical activity of the neural pathways from the HPC to ME are very dependent on the excitability of the HPC, whereas those from the AMYG to ME seem variable, depending on the activity of the AMYG.

Amygdala↗

Studies in meconium in cystic fibrosis: the activities of alpha-D-mannosidase, beta-glucuronidase, beta-D-fucosidase, acid and alkaline phosphatase.

The specific activities of alpha-D-mannosidase, beta-glucuronidase, beta-D-fucosidase, acid and alkaline phosphatase were studied in meconium from infants with cystic fibrosis (CF) and control subjects. The study revealed significant variations in the specific activity of the enzymes except for acid phosphatase. The variations were not uniform. The activities of alpha-D-mannosidase, beta-glucuronidase and alkaline phosphatase were markedly decreased (p less than 0.001, p less than 0.002, p less than 0.001, respectively), while the activity of beta-D-fucosidase was significantly increased (p less than 0.001) in meconium from the infants with CF. It is suggested that the decreased activity of alpha-D-mannosidase and beta-glucuronidase might contribute to the accumulation of the abnormal substances in CF meconium. The highly increased activity of beta-D-fucosidase raises the possibility of an additional or alternative method for screening newborns for CF using meconium as the test material.

Acid Phosphatase↗

Attempts at analysis of toxicity of pertussis vaccine. III. Effects of endotoxin on leukocytosis in mice due to lymphocytosis-promoting factor and reference preparations for determination of lymphocytosis-promoting factor.

The effect of bacterial endotoxin on the change in peripheral leukocyte population in mice due to the lymphocytosis-promoting factor (LPF) was investigated. Endotoxin affected not only the total leukocyte count but also the leukocyte proportions at any observation time. Both the coefficient and the intercept of regression of the leukocytic response on dose of LPF were modified by endotoxin. Therefore, in a valid biological assay for LPF using the peripheral leukocyte count as a response, a common reference preparation available for any test materials, irrespective of presence or absence of endotoxin, will be impracticable. Two reference preparations were tentatively established, one being a vaccine and the other an LPF preparation containing little endotoxin. A unitage of LP activity was assigned to each reference preparation. The results also showed that an LPF material to be tested for its possible effects on the lymphatic tissues or the reticuloendothelial system should be free from endotoxin.

Animals↗

A new biological assay method for histamine-sensitizing factor using survival time as a response.

A new biological assay method using survival time of mice as a graded response after histamine challenge has been developed for the histamine-sensitizing factor of pertussis bacilli. The method is relatively precise and reproducible in estimation and fairly sensitive in the validity tests of biological assay. Effect of endotoxin on the estimation by the proposed method was also investigated in case the method is applied to the control test of pertussis vaccine.

Animals↗

In vitro transfer rate of 14C from acetate-1-14C into ovarian steroids in the rat ovary during the estrous cycle and effects of LH and FSH.

Fluctuations of ovarian biosynthetic activity and effects of exogenous LH and FSH on it during the estrous cycle were investigated by measuring in vitro transfer rates of 14C from 14C-1-acetate into progesterone (P), 20 alpha-hydroxy-pregn-4-en-3-one (20 alpha-OH-P) and estrogen (estradiol and estrone, E) in the ovarian homogenates from rats autopsied at 2 hour intervals. The transfer rate of 14C from 14C-1-acetate into P was lowest in the afternoon of estrus and increased from the morning of diestrus 1, making its peaks during the afternoon of diestrus 2 and in the midnight of proestrus. The transfer of 14C into 20 alpha-OH-P was high on the days of diestrus 2 and proestrus with its peak in the afternoon of the latter day. The maximum transfer of 14C into E in the afternoon of proestrus and a high rate in the morning of estrus with relatively low one in the midnight were observed. Exogenously injected LH (150 mug) or FSH (150 mug) was either stimulatory or inhiibitory to the transfer rates of 14C from 14C-1-acetate into ovarian steroids. During day time of diestrus 2 and midnight between proestrus and estrus, the transfer of 14C into P and 20 alpha-OH-P increased by LH, and during day time of proestrus and from the afternoon of estrus to the morning of diestrus 1 decreased. The transfer of 14C into E increased by LH from the afternoon of diestrus 2 to the morning of proestrus, and decreased during the afternoon of proestrus and from the afternoon of estrus to the morning of diestrus 2. Administration of FSH was also stimulatory or inhibitory. The 14C transfer into P and 20 alpha-OH-P increased by FSH from the afternoon of estrus to the morning of proestrus, but in the afternoon of proestrus they decreased. Transfer of 14C into E increased by FSH significantly on the days of diestrus 2 and proestrus, and slightly on the day of estrus, while it decreased in the afternoon of diestrus 1.

Acetates↗

Tables for estimating the mean of distribution of logarithms of titers based on data with a pooled serum sample.

A table was constructed for use in estimating the mean of distribution of logarithms of titers based on data obtained with a pooled material instead of those with individuals in a sample. A table of standard errors of the estimator was also constructed. Examples showing the utility and applicability of the tables were presented. Several relating problems were discussed.

Animals↗

Toxicities of influenza vaccine: peripheral leukocytic response to live and inactivated influenza viruses in mice.

Intraperitoneal or intravenous inoculation of live or inactivated influenza virus induced two characteristic responses of the peripheral leukocytes in mice, an early appearing leukopenic response and late appearing lymphopenia. The former response usually developed and subsided within several hours, though the change in leukocyte population was fairly complicated depending upon the activity of the inoculated material, while the latter began several hours after inoculation and reached its minimum level in 10 to 20 hr. The agent responsible for the former may be virus pyrogen, while the latter seems to be caused by some substance(s) other than that. The early appearing leukopenic response was similar to that due to bacterial endotoxin in respect to the characteristic pattern of the change in peripheral leukocyte population, though it was relatively easy to distinguish one from the other by the length of the latent period and by the heat stability of the causative agent. Live or inactivated influenza virus causing the early appearing leukopenic response was found also to have the mouse body weight-decreasing toxicity. The significance of these findings in the laboratory control test of influenza vaccine for untoward reactions often observed in human inoculated with some inactivated influenza vaccines was discussed. The possible roles of the two agents, virus pyrogen and endotoxin, in the febrile response were mentioned.

Animals↗

Studies in meconium: disaccharidase activities in meconium from cystic fibrosis patients and controls.

Meconium ileus represents the earliest clinical manifestation of cystic fibrosis. The differences found in the composition and amount of protein, mucoprotein, mucopolysaccharides, and reducing sugars in meconium from newborns with cystic fibrosis might be of significance relative to the pathogenesis and early diagnosis of this disease. We studied the enzymatic activity of disaccharidases (lactase, sucrase, maltase, and palatinase) in meconium of infants with cystic fibrosis and controls. We found an increase in the specific activity of these enzymes in the meconium from infants with cystic fibrosis as compared to the specific activity in meconium from normal infants. The increase in the activities, expressed as micromols per gram of protein per minute was: lactase, 100 times higher; sucrase, 18 times; maltase, 4.8 times, and palatinase, 8.9 times.

Cystic Fibrosis↗