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Biomedical subjects

C H Lin

Publications and source records attributed to C H Lin.

At least 379 records · Page 21Linked to original sources
PubMed1983

Digital system for P-wave detection and synchronization of the artificial heart.

This paper describes the implementation of a microcomputer based P-wave synchronization system for the artificial heart. This system provides for synchronization of the cardiac prosthesis pump with P-wave signals from electrodes implanted in the remnant of the natural atrium. The device carries out the functions of P-wave detection and determines the duration of systole based upon a moving average of the time intervals between successive pulses. The system has been tested both on a mock circulatory system and in vivo on calves. The purpose of the paper is to provide details of the circuitry and algorithms used.

Animals↗
PubMed1982

Use of intravenous immune globulin in patients receiving bone marrow transplants.

Patients undergoing bone marrow transplantation for acute leukemia or aplastic are a great risk for the development of interstitial pneumonia associated with the cytomegalovirus (CMV). Passive immunization with a CMV immune plasma has been found to be effective for the prevention of interstitial pneumonia after marrow transplantation. Because of the limited availability of high-titered CMV plasma, we studied the kinetics of CMV antibody in bone marrow transplant patients receiving immune globulin intravenous, 5%, in 10% maltose (IGIV). Several lots of IGIV had CMV radioimmunoassay (RIA) antibody titers (1:30,000) comparable to the CMV antibody titers in the CMV immune plasma. A single infusion of 20 cc/kg of IGIV produced a mean peak CMV RIA antibody titer of 1:9,500. This titer fell to 1:1,000 after seven days. These antibody titers were approximately two-to three-fold lower than the CMV RIA antibody titers achieved after a 10 cc/kg dose of the CMV immune plasma. Administration of IGIV at doses lower than 20 cc/kg produced correspondingly lesser increases in the CMV antibody titers of recipients. At all doses, IGIV was well tolerated and caused no significant biochemical abnormalities. Some patients experienced mild elevation of their serum glucose levels and asymptomatic glycosuria. We are presently evaluating the efficacy of IGIV (20 cc/kg given once every week) for the modification of CMV infection and prevention of interstitial pneumonia after bone marrow transplantation in a randomized, controlled study. The effects of IGIV on the incidence and outcome of bacterial, fungal, and other viral infections are also being analyzed.

Antibodies, Viral↗
PubMed1982

Serial blood pressure measurements and cardiovascular disease in a Japanese cohort.

A cohort of 16,711 residents of Hiroshima and Nagasaki have participated in a program of biennial clinical examination and history taking that began in 1958. During 1958-1974, a total of 621 confirmed cases of cerebrovascular disease and 218 confirmed cases of coronary heart disease were incident. This study makes a detailed examination of the relationship between a series of biennial examination blood pressure (BP) measurements and cardiovascular disease risk. Two aspects are emphasized: the quantitative relationship between risk and both systolic blood pressure (SBP) and diastolic blood pressure (DBP), and the predictive value of BP levels some years in the past, given more recent BP determinations. Cerebral hemorrhage incidence is shown to depend markedly on recent DBP level, while earlier DBP levels make an additional important contribution to risk prediction. Corresponding SBP levels have little additional predictive value. With cerebral infarction, SBP is the more important predictor, though elevated DBP conveys some additional risk at high SBP levels. Recent BP levels are more strongly predictive for cerebral infarction than are BP levels some years earlier. Elevated SBP is also an important predictor of coronary heart disease risk in this population, while elevated DBP does not appear to be predictive at specified SBP. SBP levels several years in the past are more closely associated with coronary heart disease risk than are recent SBP readings. The dependence of BP relative risk functions on sex and age is examined and some departures from the results just listed are noted at younger ages. Implications for disease mechanism and hypertensive therapy are discussed.

Adult↗
PubMed1982

Cytomegalovirus immune plasma in bone marrow transplant recipients.

The effects of passive immunization on cytomegalovirus infection and interstitial pneumonia in marrow transplants were evaluated in a randomized, controlled trial. Twenty-four patients received cytomegalovirus immune plasma before and after transplantation, and 24 patients were controls. Although the incidence of cytomegalovirus infection was similar in the control and plasma groups, symptomatic infection (12 of 24 versus five of 24, p = 0.07) and interstitial pneumonia (11 of 24 versus five of 24, p = 0.12) occurred less frequently in the group receiving plasma. Cytomegalovirus infection occurred in 11 of 13 recipients of leukocyte transfusions and in 16 of 35 patients not given leukocyte transfusions (p = 0.02). Among patients not given leukocyte transfusions, the incidence of cytomegalovirus infection was similar in the control and plasma groups, but symptomatic infection (eight of 18 versus one of 17, p = 0.03) and interstitial pneumonia (nine of 18 versus one of 17, p = 0.01) were significantly less in the group receiving plasma. These results suggest that passive immunization modifies cytomegalovirus infection in humans and prevents interstitial pneumonia in marrow transplants especially when leukocyte transfusions are not used.

Adolescent↗
PubMed1982

Fingerprint comparison. I: Similarity of fingerprints.

Fingerprints from 61 pairs of male monozygotic twins (MZ), 47 pairs of female MZ, 40 pairs of same-sex male dizygotic twins (DZ), 44 pairs of same-sex female DZ, 4 pairs of opposite-sex DZ, and 28 brothers and 31 sisters of those twins are used for the study of fingerprint similarities. Similarities of fingerprint pattern, ridge count, and minutiae are evaluated for two population groups genetically related to each other in different degrees. It is concluded that fingerprint similarities, including pattern, ridge count, and possibly minutiae, between MZ individuals are significantly higher than those between other population groups, including DZ twins.

Dermatoglyphics↗
PubMed1982

Fingerprint comparison. II: On the development of a single fingerprint filing and searching system.

A FORTRAN program has been written to compare the minutiae coded in an"unknown" fingerprint with the minutiae of fingerprints stored in a data base. The criteria for matching are scores based on the type and number of minutiae matched. Minutiae of low relative frequency have higher scoring weights than those that are more common. The matching mechanism is tested by using a fingerprint coded several times, first by a single individual and then by six other individuals who have no previous knowledge about fingerprints. These tests yield satisfactory results.

Computers↗
PubMed1980

Repair and mutagenesis of herpes simplex virus in UV-irradiated monkey cells.

Mutagenic repair in mammalian cells was investigated by determining the mutagenesis of UV-irradiated or unirradiated herpes simplex virus in UV-irradiated CV-1 monkey kidney cells. These results were compared with the results for UV-enhanced virus reactivation (UVER) in the same experimental situation. High and low multiplicities of infection were used to determine the effects of multiplicity reactivation (MR). UVER and MR were readily demonstrable and were approximately equal in amount in an infectious center assay. For this study, a forward-mutation assay was developed to detect virus mutants resistant to iododeoxycytidine (ICdR), probably an indication of the mutant virus being defective at its thymidine kinase locus. ICpR-resistant mutants did not have a growth advantage over wild-type virus in irraidated or unirradiated cells. Thus, higher fractions of mutant virus indicated greater mutagenesis during virus repair and/or replication. The data showed that: (1) unirradiated virus was mutated in unirradiated cells, providing a background level of mutagenesis; (2) unirradiated virus was mutated about 40% more in irradiated cells, indicating that virus replication (DNA synthesis?) became mutagenic as a result of cell irradiation; (3) irradiated virus was mutated much more (about 6-fold) than unirradiated virus, even in unirradiated cells; (4) cell irradiation did not change the mutagenesis of irradiated virus except at high multiplicity of infection. High multiplicity of infection did not lead to higher mutagenesis in unirradiated cells. Thus the data did not demonstrate UVER or MR alone to be either error-free or error-prone. When the two processes were present simultaneously, they were mutagenic.

Animals↗
PubMed1980

Glyceraldehyde-3-Phosphate Dehydrogenase in Greening Zea mays L. Leaves.

Nicotinamide adenine dinucleotide phosphate (NADP)-dependent glyceraldehyde-3-phosphate dehydrogenase (GPDH) (EC 1.2.1.13), a chloroplast enzyme, had low activity in etioplasts of maize leaves. A light dependent increase of enzyme activity of 7-day-old etiolated seedlings showed a lag period of about 2.5 hours followed by a rapid increase in activity during the next 10 hours. The chlorophyll content followed a similar pattern of increasing concentration, but its formation was not directly related to NADP-GPDH formation. The specific activity of NADP-GPDH was lowest in the morphologically youngest tissue near the base of the lamina. The increase in NADP-GPDH was inhibited by cycloheximide but not by chloramphenicol. This indicates that at least some of the enzyme polypeptides are synthesized by 80S ribosomes in the cytoplasm, transported into chloroplasts and become active in chloroplasts. In etiolated maize shoots subjected to a combination of both 3-(p-chlorophenyl)-1,1-dimethylurea, monuron at 7 x 10(-5)m and far red light treatment for 15 hours, the NADP-GPDH activity increased 42% over the dark control compared to 70% increase for the light control. It is concluded that NADPH is not absolutely required for the activation of NADP-GPDH in maize leaves under physiological conditions.

Journal Article↗
PubMed1980

Cytomegalovirus infections associated with leukocyte transfusions.

Patients randomized to receive or not to receive prophylactic leukocyte transfusions were evaluated prospectively for serologic, histologic, and cultural evidence of cytomegalovirus infection. Recipients of prophylactic leukocyte transfusions and control subjects were similar with regard to age, sex, underlying disease, immunosuppressive therapy, and number of other transfusions. The recipients of prophylactic leukocyte transfusions (mean, 23.1) had significantly more cytomegalovirus infections (19 of 31 versus seven of 27, p = 0.01) than did control patients receiving no leukocytes or only therapeutic leukocyte transfusions (mean, 3.8). Twenty-seven of 66 donors of leukocytes were seropositive for cytomegalovirus complement-fixation antibody, but cytomegalovirus was not isolated from any of 62 leukocyte transfusions cultured for virus. These results are consistent with the hypothesis that latent cytomegalovirus may be present in leukocytes of blood donors with previous cytomegalovirus infection and after transfusion may be activated to produce active cytomegalovirus infection.

Adolescent↗
PubMed1979

Pneumococcal infections after human bone-marrow transplantation.

Seven of 26 long-term survivors (greater than 7 months post-transplant) of bone-marrow transplantation developed penicillin-sensitive pneumococcal infections more than 7 months after transplantation. One patient had two infections. Six of eight infections were associated with pneumococcal bacteremia, and Streptococcus pneumoniae type 6A was isolated in three cases. Two infections were fatal. All patients had normal nematopoietic function, and none was receiving immunosuppressive therapy. The development of pneumococcal infection was significantly associated with males and with abnormally low or high serum IGG and IgM levels but not with graft-versus-host disease. Serum opsonic activity for S. pneumoniae type 6A was decreased in six of the seven patients when compared to normal pooled serum in an in-vitro bactericidal assay. Four of the six patients with impaired opsonic activity had low serum antibody levels for S. pneumoniae type 6A capsular polysaccharide, while the other two patients had low serum CH100 complement activity. Bone-marrow transplant recipients have an increased susceptibility to pneumococcal infections and should be evaluated for prophylactic penicillin or pneumococcal vaccination.

Adolescent↗
PubMed1977

Localization of Cinnamic Acid 4-Monooxygenase and the Membrane-bound Enzyme System for Dhurrin Biosynthesis in Sorghum Seedlings.

The localization of three monooxygenase (hydroxylase) enzyme systems which occur in dark-grown seedlings of Sorghum bicolor has been studied. Cinnamic acid 4-hydroxylase (CAH) (trans-cinnamate 4-monooxygenase, EC 1.14.13.11), which has been increasingly utilized in plants as a marker for the endoplasmic reticulum, migrated with that fraction in continuous and discontinuous sucrose gradients. When 10 mm MgCl(2) was used to shift the density banding of the marker enzyme, NADPH cytochrome c reductase, from 1.12 to 1.17 g/cm(3), the CAH activity was displaced as well.The membrane-bound enzyme system involved in the biosynthesis of the cyanogenic glucoside dhurrin was also shown to be closely associated with the endoplasmic reticulum. This system contains hydroxylases capable of hydroxylating tyrosine to form N-hydroxytyrosine and hydroxylating p-hydroxyphenylacetonitrile to form p-hydroxy-(S)-mandelonitrile.

Journal Article↗