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Biomedical subjects

S Lin

Publications and source records attributed to S Lin.

At least 541 records · Page 30Linked to original sources
PubMed1990

Accuracy of Doppler ultrasound in evaluating changes of left ventricular diastolic properties.

In order to evaluate the effect of an increase in preload caused by contrast medium (Renografin-75) on Doppler echocardiographic indices of left ventricular diastolic properties, left ventricular pressure using a catheter tip micromanometer and pulsed-Doppler measurement of transmitral flow signals were measured simultaneously in 15 patients with coronary artery disease pre- and post-left ventricular angiography. After left ventricular angiography, changes in indices determined from left ventricular pressure were significant: left ventricular end-diastolic pressure increased from 17 +/- 2 mmHg to 24 +/- 2 mmHg (mean +/- SE) (P less than 0.001), maximum -dP/dt increased from 1,129 +/- 63 to 1,307 +/- 90 mmHg/sec (P less than 0.005), and time constant decreased from 73 +/- 2 to 67 +/- 1 msec (P less than 0.01). Changes in Doppler-derived indices were also significant: A/E ratio decreased from 0.99 +/- 0.08 to 0.81 +/- 0.07 (P less than 0.01), peak velocity of early diastolic filling increased from 0.61 +/- 0.03 to 0.79 +/- 0.03 M/sec (P less than 0.01), and deceleration rate increased from 3.1 +/- 0.2 to 4.6 +/- 0.2 M/sec 2 (P less than 0.01). Changes in Doppler echocardiographic indices (DR, acceleration half time, deceleration half time, and A/E ratio) were accompanied by changes in time constant and maximum -dP/dt after left ventricular angiography. However, the correlations between changes in hemodynamic indices and changes in Doppler echocardiographic indices were poor (r = 0.06 to 0.67).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Modular total shoulder: early experience and impressions.

All design considerations in shoulder arthroplasty are based on reconstructing normal anatomy and enhancing prosthetic fixation, particularly on the glenoid side. These goals are further enhanced by meticulous attention to detail in placement of the component parts relative to the bony anatomy. In addition, great attention must be paid to management of the soft tissue tensions and placement of the component parts relative to soft tissue origins and insertions so that asymmetric overloading of the components can be avoided and loosening and wear can be minimized. The problem of management of prosthetic replacement with associated massive rotator cuff tears continues to be a dilemma. Use of an oversized humeral head articulating with the acromion can offer a compromise solution to the problem. This technique can be combined with altered glenoid component placement or reshaping of the bony glenoid to accommodate its altered relationship with the humeral articular surface. Future design changes are needed to deal with this complex problem.

Evaluation Studies as Topic↗
PubMed1990

Changes in reproductive function among remarried women: the effects of spousal characteristics.

"This paper examines the relationship between change in childbearing function from a woman's first to second marriage and the degree of similarity between her first and second husbands in age, education, and religion. Using data from the [U.S.] 1982 National Survey of Family Growth, the specific hypothesis tested is: where plans are similar, the second husband tends to resemble the first to a greater extent than where childbearing functions differ. Separate tests relating to age, education, and religion provide only limited support for this hypothesis. However, when the various tests are considered collectively as a system, the weight of the evidence provides general support for the hypotheses. The implications of these findings for understanding trends in marriage are discussed."

Americas↗
PubMed1990

[Measurement of nuclear DNA content of laryngeal carcinoma and determination of estrogen receptor (ER) level in laryngeal cancer cells].

In 39 patients with laryngeal carcinoma, nuclear DNA content was measured, and the ER in cancer cells of 23 cases determined. The following results were obtained: 1. For all laryngeal carcinomas, there were two patterns-diploid and non-diploid carcinomas. The majority (27/39) belonged to the non-diploid pattern. 2. The laryngeal carcinomas of non-diploid pattern or with higher level of DNA content were easily metastasized to cervical nodes. This kind of cancers were more often seen in clinically advanced cases. Patients with these carcinomas, judged by the results of one-year's follow-up, had poor prognosis. 3. Carcinomas with diploid pattern or with lower level of DNA content had the tendency to become ER positive. The cervical node metastases was more easily taking place in ER negative carcinomas. Some indirect relationship between DNA content and ER in laryngeal cancers may exist.

Aneuploidy↗
PubMed1990

[Pathologic studies of Guillain-Barre syndrome (GBS) and 13 rabbits with experimental allergic neuritis].

Pathological studies were carried out of Guillain-Barré syndrome (GBS) and 13 rabbits with experimental allergic neuritis. It was shown that the postmortem pathological findings in the patients, who died at different stages of GBS, varied in the degree of axon degeneration, the amount of plasmocyte infiltration, the appearance of phagocytes and the proliferation of Schwann cells and fibroblast. But in all the cases in this series segmental demyelination of the peripheral nerve with lymphocyte infiltration occurred without exception. In the rabbits with EAN, it was found that there were small foci of demyelination in the cerebral white matter and diffuse hemorrhage in the grey matter of the spinal cord. Lymphocyte infiltration in the EAN rabbit group was seen in a much more extensive manner than that found in cases of the patients with GBS, but the proliferation of Schwann cells and fibroblast seemed to take place more slowly in comparison with the similar process as was revealed in the patients who died from GBS.

Adolescent↗
PubMed1989

Heme regulates expression of phycobiliprotein photogenes in the unicellular rhodophyte, Cyanidium caldarium.

Allophycocyanin and phycocyanin in the red alga (Cyanidium caldarium) are chloroplast-encoded, light-harvesting accessory pigments composed of alpha and beta subunit polypeptides (17-19 kDa) to which 1 or more residues of the heme-derived bile pigment chromophore phycocyanobilin are attached by cysteinyl thioether linkages (Offner, G.D., and Troxler, R.F. (1983) J. Biol. Chem. 258, 9931-9940). Western blot experiments utilizing phycobiliprotein antisera revealed that immunoreactive allophycocyanin and phycocyanin apoproteins were absent in cells grown in the dark and present in cells exposed to light. Northern blot experiments using genomic DNA hybridization probes indicated that phycobiliprotein mRNAs were absent in the dark, whereas cells exposed to light contained two allophycocyanin mRNA transcripts, 1.4 and 1.6 kilobases in length, and one phycocyanin mRNA transcript, 3.0 kilobases in length, providing evidence that phycobiliproteins are encoded in photogenes which are only transcriptionally active in the light. Northern and Western analyses demonstrated that cells incubated in the dark with the heme precursor delta-aminolevulinate contained allophycocyanin and phycocyanin mRNAs and apoproteins, indistinguishable in size, number, and quantity from those made in the light. Cells incubated in the dark with delta-aminolevulinate, protoporphyrin IX, or heme, but not biliverdin or phycocyanobilin, synthesized allophycocyanin and phycocyanin alpha and beta apoproteins, suggesting a role for heme in the control phycobiliprotein gene expression. Cells incubated with heme in the dark produced allophycocyanin and phycocyanin mRNA transcripts, but did not produce mRNAs for four other photogenes coding for a P-700 reaction center protein, a 32-kDa herbicide-binding protein, and the large and small subunits of ribulose-bisphosphate carboxylase. These results show, for the first time, that heme is a regulatory factor specifically involved in transcriptional regulation of chloroplast genes for phycobiliproteins.

DNA Probes↗
PubMed1989

The immunosuppressant FK506 selectively inhibits expression of early T cell activation genes.

FK506, a neutral macrolide with immunosuppressive properties, was shown to selectively and rapidly inhibit the accumulation of IL-2 mRNA, as well as the mRNAs of other early (E) phase T cell activation genes such as IL-3, IL-4, GM-CSF, TNF alpha, IFN-gamma, and c-myc in activated human peripheral blood T cells. The activity of FK506, when compared to Cyclosporin A, another immunosuppressant, was 10 to 100x more potent in its ability to inhibit IL-2 mRNA synthesis. FK506 inhibited IL-2 mRNA accumulation in Con A, Con A plus PMA, Ionomycin plus PMA, anti-CD3, and anti-CD3 plus PMA activated T cells. Transcripts from other T cell gene classes such as the immediate early (IE) phase gene, c-fos, the late phase (L) genes, transferrin receptor, IL-2R alpha-chain, and TNF-beta, and the constitutive class genes glyceraldehyde-3-phosphate dehydrogenase and class I MHC HLA-B7 were not affected by FK506. The macrolide Rapamycin, which is structurally related to FK506, had no inhibitory effect on IE, E, L, or constitutive class mRNAs, but it appeared to increase the levels of the E-phase transcripts that were inhibited in FK506 treated T cells. The effect of FK506 on inducible genes in non-T and non-lymphoid human cells was studied in LPS-induced monocytes and PMA or IL-1 activated synovial fibroblasts. FK506 did not affect expression of the mRNAs for IL-1 alpha or IL-1 beta in human monocytes, or of stromelysin, collagenase, or TIMP in synovial fibroblasts. Nuclear run-off transcription studies indicate that FK506 inhibits transcription of the IL-2 gene. These studies suggest that Cyclosporin A and FK506 may effect a common early event in the T cell activation pathway.

Base Sequence↗
PubMed1989

The effect of pterygia on contrast sensitivity and glare disability.

To detect subtle changes in visual acuity, we measured spatial contrast sensitivity in 12 patients with pterygium (Group 1) and compared their results with those from an age- and sex-matched control population (Group 2). Glare disability was also measured in each group. Measurements of contrast sensitivity were lower in Group 1 at all spatial frequencies than those of Group 2, independent of the testing device used. Glare disability was significantly increased in Group 1 compared to Group 2. Our studies indicate that contrast sensitivity and glare disability testing may provide additional objective methods for documenting impaired vision in patients with pterygium when Snellen visual acuity is minimally affected.

Adult↗
PubMed1989

A study of the separate effects of influence factors and their coupled interactions on cryoinjury of human erythrocytes.

The separate effects of five influence factors and their coupled interactions on cryoinjury of human erythrocytes were investigated experimentally and statistically. The five factors, each having three levels, were as follows: (1) cooling rate: -0.5, -140, and -800 degrees C/min; (2) warming rate: +0.5, +25, and +200 degrees C/min; (3) hematocrit: 2, 11, and 60%; (4) concentration of cryoprotectant (glycerol): 1, 2, and 4 M in PBS; and (5) holding temperature at which the frozen samples were kept: no hold, -75 degrees C for 1.5 hr, and -196 degrees C for 1.5 hr. Twenty-seven special tests, which were chosen from the 243 possible tests by using the Fractional Factorial Design Technique, an optimum seeking technique, were performed. The conclusions are: (1) the cooling rate is the most significant or sensitive factor causing cryoinjury to the cells; (2) the main effects of the hematocrit and the concentration of cryoprotectant, the interaction between the cooling rate and the warming rate, and the interaction between the cooling rate and the concentration of cryoprotectant are next most significant; (3) the main effect of warming rate, and the interaction between the holding temperature and the cooling rate are less significant; (4) the holding temperature below -75 degrees C, and the remaining interactions between two factors are relatively not significant; and (5) in the present study, the optimal combination of the five factors for the survival of the cells is: cooling at -0.5 degrees C/min, warming at +0.5 degrees C/min, hematocrit at 11%, glycerol concentration at 4 M in PBS, and holding temperature below -75 degrees C.

Biometry↗
PubMed1989

Mutations in familial Creutzfeldt-Jakob disease and Gerstmann-Sträussler-Scheinker's syndrome.

A host protein encoded by the gene specifying the scrapie amyloid precursor affects pathogenesis of the transmissible spongiform encephalopathies: Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker's syndrome (GSS), and kuru in man, and scrapie in animals. We found a mutation in this gene of two patients with CJD from one family and a second mutation in the same gene in three patients with GSS from another family. The mutation in two related familial CJD patients changed glutamine in position 200 tolysine. This mutation was absent in other individuals including unrelated patients with familial CJD, sporadic CJD, and GSS. The other mutation in three GSS patients changed proline in position 102 to leucine, the same mutation described recently in some GSS families. We did not find it in six unaffected relatives of the GSS patients or in other individuals including sporadic and familial CJD patients. A rare insertion described earlier in one CJD family was also absent in all tested individuals.

Base Sequence↗
PubMed1989

Inpatient violence: trait and state.

This study compared patients who showed persistent violence, transient violence and no violence. The presence of neurological abnormalities was found to be the factor that differentiated most clearly among the three groups. The persistently violent patients, in addition to showing significantly more neurological abnormalities, also evidenced a more disturbed family background. Both violent groups had a higher incidence of violent crime prior to hospitalization than the nonviolent controls. A logistic regression model simultaneously relating the effects of six factors on violent behavior was developed and used to predict violent group membership.

Adult↗
PubMed1989

Neurological impairment in violent schizophrenic inpatients.

This study relates violent behavior of schizophrenic inpatients to demographic, historical, EEG, neurological, and neuropsychological variables. Patients were classified into high (N = 28), low (N = 27), or no (N = 34) violence groups. There were no significant differences among the groups on demographic or historical variables, except for prevalence of violent crime, which was higher in both violent groups than in nonviolent patients. Neurological and neuropsychological abnormalities differentiated the groups, with the high violence group evidencing more abnormalities than the other two groups in the area of integrative sensory and motor functions. The authors suggest that violence as well as neurological and neuropsychological deficits may characterize a more severe form of schizophrenia.

Adult↗
PubMed1988

Clostridium difficile toxin B induces reorganization of actin, vinculin, and talin in cultured cells.

Clostridium difficile toxin B is a powerful cytopathic agent which causes animal cells in culture to become rounded and arborized, an effect similar to that induced by the cytochalasins. In this study, we demonstrated that the morphological effects of the toxin are directed specifically against the actin and related components of the cytoskeleton. Dramatic disruption and reorganization of the actin stress fibers were detectable prior to significant changes in cell shape and alterations in the microtubular and intermediate filament networks. Along with F-actin, the adhesion plaque proteins, vinculin and talin were localized in intoxicated cells in a patchy pattern reminiscent of that seen in cells treated with phorbol esters or transformed by oncogenic viruses. A quantitative fluorescence assay for cellular F-actin showed that these morphological changes were accompanied by a modest net depolymerization of only 15 to 20% of the actin filaments in the cell, and that depolymerization was closely correlated with changes in cell shape. In complementary studies on cells spreading on a substrate, we found that the toxin affected the actin content and the shape of the processes extended from the cell body. As in cells treated with cytochalasin, there was a differential response between normal and virally transformed cells spreading in the presence of the toxin. The results of this study support the view that C. difficile toxin B affects one or more cellular components that regulate the structure and function of the actin cytoskeleton, and that its predominant effect is to cause a dramatic disruption of stress fibers and relocalization of the F-actin.+

Actins↗