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Biomedical subjects

Y S Yuh

Publications and source records attributed to Y S Yuh.

At least 19 recordsLinked to original sources

High-resolution cranial ultrasound in the shaken-baby syndrome.

With limited near-field resolution and accessible acoustic windows, sonography has not been advocated for assessing central nervous system injuries in the shaken-baby syndrome. Our purpose was to correlate high-resolution ultrasonographic characteristics of central nervous system injuries in whiplash injuries and the shaken-baby-syndrome with MRI and CT. Ultrasonographic images of 13 infants, aged 2-12 months, with whiplash or shaking cranial trauma were reviewed and compared with MRI in 10 and CT in 10. Five patients had serial ultrasonography and MRI or CT follow-up from 1 to 4 months after the initial injury. With ultrasonography we identified 20 subdural haematomas. MRI and CT in 15 of these showed that four were hyperechoic in the acute stage, three were mildly echogenic in the subacute stage, and that one subacute and seven chronic lesions were echo-free. Five patients had acute focal or diffuse echogenic cortical oedema which evolved into subacute subcortical hyperechoic haemorrhage in four, and well-defined chronic sonolucent cystic or noncystic encephalomalacia was seen at follow-up in two. Using ultrasonography we were unable to detect two posterior cranial fossa subdural haematomas or subarachnoid haemorrhage in the basal cisterns in three cases, but did show blood in the interhemispheric cistern and convexity sulci in two. U1-trasonography has limitations in demonstrating abnormalities remote from the high cerebral convexities but may be a useful adjunct to CT and MRI in monitoring the progression of central nervous system injuries in infants receiving intensive care.

Battered Child Syndrome↗

A single dose of nebulized budesonide decreases exhaled nitric oxide in children with acute asthma.

This study was conducted to investigate whether a single dose of nebulized budesonide effectively decreased airway inflammation as demonstrated by exhaled nitric oxide (eNO) levels. A single dose of nebulized budesonide, but not nebulized terbutaline, rapidly decreased eNO levels in 6 hours. The decrease in eNO levels induced by nebulized budesonide was correlated to an increase in peak expiratory flow rate.

Adolescent↗

Perinatal cytomegalovirus infection complicated with pneumonitis and adrenalitis in a premature infant.

Cytomegalovirus causes pneumonia, hepatitis, thrombocytopenia, and hemolytic anemia. Cytomegalovirus adrenalitis in premature infants, however, is rare. This report described a premature newborn who had progressively worsening hyperbilirubinemia, pancytopenia, and hepatosplenomegaly at the age of 4 days. The baby's mother had prolonged rupture of amniotic membrane for about 8 weeks. The infant received exchange blood transfusion, empiric antibiotics treatment, and mechanical ventilation. Pneumonia and sepsis developed at the age of 18 days. Serum anticytomegalovirus immunoglobulin M and urine virus culture were positive for cytomegalovirus. The baby died at the age of 22 days. Autopsy showed cytomegalovirus infection complicated with interstitial pneumonitis and pulmonary edema, subacute bronchopulmonary dysplasia with interstitial fibrosis, and adrenalitis. We concluded that the functional status of the adrenal glands in cytomegalovirus-infected premature newborns who have unexplained electrolytes imbalance, fever, diarrhea, weight loss, or hypotension should be closely followed because of the possible involvement of adrenal glands.

Adrenal Gland Diseases↗

The occurrence rate and correlation factors of thumb-in-palm posture in newborns.

Bilateral fisting of hands, including adduction and infolding of the thumbs (cortical thumbs), is an expected finding in term infants. Clinically, the cortical thumb position is a transient and normal, but not general, hand posture in newborns. The aim of this study was to analyze the rate of occurrence and the factors possibly affecting the cortical thumb (thumb-in-palm) posture in term newborns. We enrolled 197 low-risk term newborns and observed the posture of their hands once daily from the day of birth for 3 consecutive days. The occurrence rates of the thumb-in-palm posture of the right hand on the first, second, and third days were 62.8%, 60.9%, and 50%, respectively, and those of the left hand were 60.3%, 55.8% and 53.2%, respectively. There was a significant reduction on a day-to-day basis in the right hand and an insignificant reduction in that of the left hand. Factors including sex, gestation age, birth weight, method of delivery, and alertness were analyzed, and no relationship was evident between these factors and the occurrence rates of the cortical thumb posture. Our observations suggest that the cortical thumb posture is indeed a predominant hand posture in our hospital, yet it is not a general phenomenon in all term newborns.

Age Factors↗

The effectiveness of single and multiple applications of triple dye on umbilical cord separation time.

UNLABELLED: The effectiveness of single and multiple applications of triple dye for umbilical cord care in the umbilical cord separation time (UCST) was evaluated in 180 neonates. Seven neonates were excluded, three where the cord stump separation time was uncertain and four to whom contact was lost. The participating neonates were randomly assigned to two groups. Group 1, 101 neonates, were treated with a regimen of a single application of triple dye. Group 2, 79 neonates, were treated with multiple applications of triple dye. Complete information was obtained from 97 neonates (96.2%) in group 1 and 76 (96%) in group 2. The UCST was 12.6 +/- 0.45 (mean +/- SE) days in group 1 and 16.68 +/- 0.65 days in group 2 (P < 0.0001) and showed no significant association with infants' gender, mode of delivery, gravidity, gestational age, birth weight, or hospital stay. CONCLUSION: A single application of triple dye may be a more favourable regimen with a similarly antimicrobial effect, a shorter UCST and may be more cost effective than multiple applications of triple dye in umbilical cord care.

Anti-Infective Agents↗

Determination of blood sugars by high pressure liquid chromatography with fluorescent detection.

In this study, a high pressure liquid chromatography method with fluorescent detector was developed to analyze blood galactose, lactose and glucose simultaneously. Plasma sugars were prepared as fluorescent derivatives to react with FMOC-hydrazine (9-fluorenyl methyl chloroformate). A C18 reversed phase column and a fluorescent detector were used and run in ambient. The resolution index of galactose and glucose derivatives in the analytical method was 1.15. The coefficients of variation of the analysis were less than 7.5%. The concentration of FMOC-hydrazine did not significantly influence the analytical results for determination of the concentration of galactose. However, the ratios of acetonitrile in the mobile phase significantly affected the analysis of the fluorescent derivatives of sugars. The sensitivity of this method for galactose detection was 5 micrograms ml-1, and the required plasma volume for testing was only 25 microliters each. This analytical method was successfully applied to study the pharmacokinetics of galactose in vivo in a rabbit model.

Animals↗

MR findings of Werdnig-Hoffmann disease in two infants.

We report two infants with Werdnig-Hoffmann disease diagnosed by means of spinal MR imaging, histopathologic examination of muscle biopsy specimens, cloned DNA analysis, electrophysiological examination, and clinical history. The MR findings were consistent with previous histopathologic reports.

Atrophy↗

Neuroimaging findings in late infantile GM1 gangliosidosis.

Late infantile GM1 gangliosidosis is an extremely rare metabolic disorder with clinical features of seizure and progressive motor and mental retardation without facial dysmorphism or visceral organomegaly. We report the CT and MR imaging findings in one infant, which included abnormalities of the cerebral cortex, white matter, and deep nuclei.

Brain↗

Chromosome number of Trichomonas vaginalis.

Chromosome number of an axenically grown Trichomonas vaginalis isolate was studied using a 1 mM solution of colchicine and a hypotonic swelling technique. The diploid chromosome number was 2n = 6 [corrected]. Each pair of chromosomes can be identified by its morphology and size. This observation could be important with respect to gene mapping and molecular cloning for genes of T. vaginalis.

Animals↗

Cytotoxic factors released by dengue virus-infected human blood monocytes.

Human monocyte-derived cytotoxic factors (CF) induced by dengue virus were studied. Using several human leukemia cell lines as precursors, the biological activities of CF in conditioned medium from dengue virus-infected monocytes were demonstrated through the measurement of tumor cell growth inhibition. The conditioned medium from dengue virus infected monocytes suppressed significantly growth of CEM, HL60, K562, and U937 cells. In the presence of 10% conditioned medium (v/v) from dengue virus infected monocytes, DNA synthesis of U937 cells, as measured by [3H]thymidine incorporation, decreased by 99% in contrast to their synthesis in conditioned medium from noninfected control monocytes, which did not have any suppressive effect. Partial characterization of CF showed that it is a proteinase-K-sensitive and heat-labile protein with a molecular mass over 100 kDa. Employing a flow cytometric analysis of the cell cycle, it was found that U937 cells, treated either with conditioned medium from dengue virus infected monocytes or with CF, but not treated with conditioned medium from noninfected monocytes, showed cell-cycle arrest in G1 phase by 48 hr. This suppressive effect of CF on U937 growth was dose- and time-dependent. These results suggest that dengue virus-infected monocytes may produce CF to target myeloid cells, resulting in the hematological changes observed in patients with dengue fever.

Adult↗

Chromosomal screening of mentally retarded school children in Taipei.

The major concern of the national population policy in Taiwan in recent years has been to lower the incidence of hereditary diseases and mental retardation in the general population. It has been estimated that there are around 10,000 mentally retarded school children in Taiwan. If effective chromosomal screening can be extended to these children, some of the family members who are carriers of balanced chromosomal rearrangements may benefit from follow-up studies and genetic counseling. The present report is the result of a pilot study conducted from 1988 to 1991 to explore the possibility of chromosomal screening of mentally retarded school children in Taipei. A total of 871 blood samples were collected from 1,147 children registered in 46 schools or residing in homes for the retarded. Chromosomal analysis was successfully accomplished on 674 out of 871 blood samples. The following chromosomal abnormalities were observed: 28 Down's syndrome, four Klinefelter syndrome, one XYY, one triple X, 11 translocations, seven inversions, four mosaics, three duplications, one deletion and one with an extra marker chromosome. After follow-up cytogenetic analyses of 13 families with probands with structural chromosomal anomalies, three of these families were shown to have one or two carriers of balanced translocated chromosomes. It seems that the present screening system would not be practical or cost-effective if it were applied island-wide in the future.

Adolescent↗

Glucocorticoid effect on oncogene/growth gene expression in human T lymphoblastic leukemic cell line CCRF-CEM. Specific c-myc mRNA suppression by dexamethasone.

Glucocorticoids induce growth inhibition and eventually cause cell lysis in certain sensitive leukemic cells. To investigate how glucocorticoids interact with cell growth pathways, we studied the expression of 14 growth-related genes in dexamethasone-treated CEM-C7A cells, a steroid-sensitive clone of the CCRF-CEM cell line, and in several closely related clones. The 14 genes studied were chosen to represent four different levels of mitogenic signal transduction. Detectable mRNA levels were found for 8 of the 14 genes, but among these only c-myc expression was obviously suppressed by dexamethasone. The c-myc mRNA levels declined abruptly during the first 12 h after addition of 1 microM dexamethasone, and maximal suppression occurred by 18 h. This change was not seen in the C7A controls, in the glucocorticoid-resistant, receptor-deficient clone ICR-27, or in the glucocorticoid-resistant, receptor-positive clone C1. H.10, a hybrid clone between C1 and ICR-27, showed restoration of the sensitive phenotype, and in H.10 cells the c-myc mRNA was also suppressed by dexamethasone. Our results suggest that: 1) functional glucocorticoid receptor is required for inducing c-myc suppression. 2) In dexamethasone-resistant cells with functional receptors c-myc is not suppressed. 3) The growth arrest induced by glucocorticoids correlates with, and may be regulated via, suppression of c-myc expression.

Blotting, Northern↗

Mechanisms of glucocorticoid function in human leukemic cells: analysis of receptor gene mutants of the activation-labile type using the covalent affinity ligand dexamethasone mesylate.

In the cultured acute lymphoblastic leukemic (ALL) cell line, clones of sensitive cells are killed by receptor-occupying concentrations of glucocorticoids. In addition, several types of resistance have been identified. The types of resistance are r- (glucocorticoid binding site loss), ract/l (activation labile receptors) and r+ly- (defective lysis mechanism). The two types of receptor mutants have been examined for the presence and expression of the glucocorticoid receptor (GR) gene. Southern blot analysis, using a full-length cDNA probe for human GR, shows that the gene in both is grossly intact. Examination of the expression of the gene by Northern blots reveals the presence of normal, 7-kb message in both types of receptor mutants, though in amounts somewhat reduced from wild-type. This report focuses on the activation labile mutants. Since characterization of these mutants suggests that they can bind ligand but not retain it during activation, we hypothesized that they would respond normally to a ligand that could not be lost during activation. This seems to be the case. When the covalent affinity ligand dexamethasone mesylate, itself a partial glucocorticoid agonist/antagonist, is used, the ract/l cells are killed to an extent corresponding to that evoked by a sub-optimal concentration of the full agonist dexamethasone. We conclude: (1) that the ract/l receptors can function to kill cells if provided a ligand that they do not lose during activation; (2) that the partial agonist activity of dexamethasone mesylate for cell killing is not due to release of a small amount of free dexamethasone; (3) that the poor agonist activity of dexamethasone mesylate receptor complexes suggests that the role of steroid is strictly to participate in conversion of the receptor to its DNA binding form, after which presence of the steroid actually interferes with proper receptor action.

Cell Division↗

Complementation between glucocorticoid receptor and lymphocytolysis in somatic cell hybrids of two glucocorticoid-resistant human leukemic clonal cell lines.

Somatic hybrids between two glucocorticoid-resistant clonal cell lines, CEM C1 and ICR-27, isolated independently from the CCRF-CEM human lymphoblastoid cell line, were constructed to investigate the complementation effect between the glucocorticoid receptor and the gene product(s) for inducing receptor-mediated lymphocytolysis. CEM C1 (r+ly-) has a normal amount of functional glucocorticoid receptor as compared to the steroid-sensitive clonal line CEM C7. Clone ICR-27 (r-ly?), which was originally isolated following mutagenesis of CEM C7 with the mutagen ICR 191, has few glucocorticoid receptors as determined by whole-cell receptor assay. The eight randomly selected CEM C1 X ICR-27 hybrid clones all showed sensitivity to 10(-6) M dexamethasone (ly+). The receptor site content of two near-tetraploid hybrids chosen for analysis was close to that of CEM C1 (r+). Hybrids constructed between CEM C1 and the receptor-bearing, steroid-sensitive clone, CEM C7 (r+ly+) also showed glucocorticoid sensitivity, and their receptor sites corresponded to the sum of those of CEM C1 and CEM C7 (r+r+ly+). These results indicate: that CEM C1 has no trans-active inhibitor of lysis; that CEM C1 has intact glucocorticoid receptor; and that ICR-27 and CEM C1 complement one another to restore lymphocytolysis. Therefore, CEM C1 cells can serve as a donor of human glucocorticoid receptors.

Cell Line↗

Analysis of incomplete multivariate data from repeated measurement experiments.

This paper analyses two sets of data that consist of repeated measurements with missing data. The missing observations always occur at the end of the series of repeated measurements. The score test for multivariate normal data is used to compare treatment groups; if the original data are not multivariate normal they are replaced by expected normal scores.

Animals↗

Surgery for nasal obstruction--evaluation by rhinomanometry.

Nasal obstruction is predominantly a subjective patient complaint. The physical examination of the nose for nasal obstruction is a subjective evaluation as well. While the history and physical examination are reasonable diagnostic indicators, an objective means of evaluation is needed. Rhinomanometry measures nasal obstruction objectively and reliably. Thirty-six patients with nasal obstruction were evaluated by rhinomanometry before and after nasal surgery. The results are reported here. Rhinomanometry confirms the effectiveness of intranasal surgery. Using rhinomanometry, various techniques of intranasal surgery are evaluated, and several interesting observations are made.

Adolescent↗

Regional myocardial hemodynamic and metabolic effects of ionic and nonionic contrast media in normal and ischemic states.

The effects of intracoronary injection of two nonionic contrast media (iohexol and metrizamide) on myocardial contraction and chemical composition of coronary sinus (CS) blood were compared with those caused by the standard ionic contrast material for coronary angiography, sodium meglumine diatrizoate (R76), in 14 anesthetized dogs. The effects of each agent on regional contractility were compared in the normal state and in the presence of a critical coronary artery stenosis. The three contrast media produced equivalent decreases in hematocrit and sodium (both NS), but R76 caused a greater increase in CS osmolality (p less than 0.02). R76 caused a significant decrease in CS potassium and ionized calcium (both p less than 0.001), but neither nonionic contrast medium caused a significant change in either potassium or calcium. In the normal state, R76 caused initial transient (less than 10 seconds) increases in both end-diastolic (p less than 0.006) and end-systolic segment length (p less than 0.02) and a decrease in rate of change of segment length (dL/dt) (p less than 0.002). The nonionic agents caused a mild increase in dL/dt (p less than 0.04) and a decrease in end-systolic segment length (p less than 0.03); both returned to control levels within 1 minute. In the presence of a stenosis, R76 caused a more severe and prolonged increase in end-diastolic and end-systolic segment lengths (p less than 0.03) and a decrease in dL/dt (p less than 0.002), which did not return to control within 2 minutes. The effects of the nonionic agents were similar in both normal and diseased states. We conclude that nonionic contrast media produce fewer alterations than ionic contrast media in coronary sinus blood chemistry and myocardial contractile state. The effect of ionic contrast media on regional contraction is accentuated in the presence of coronary artery stenosis.

Animals↗