PubMed Health⌕ Search

Biomedical subjects

Y J Lin

Publications and source records attributed to Y J Lin.

141 records · Page 8Linked to original sources
PubMedDate not supplied

A limit on spin-charge separation in high-Tc superconductors from the absence of a vortex-memory effect.

There is a long-standing debate about whether spin-charge separation is the root cause of the peculiar normal-state properties and high superconducting transition temperatures of the high-Tc materials. In the proposed state of matter, the elementary excitations are not electron-like, as in conventional metals, but rather the electron 'fractionalizes' to give excitations that are chargeless spin-1/2 fermions (spinons) and charge +e bosons (chargons). Although spin-charge separation has been well established in one dimension, the theoretical situation for two dimensions is controversial and experimental evidence for it in the high-Tc materials is indirect. A model with sharp experimental tests for a particular type of separation in two dimensions has recently been proposed. Here we report the results of those experimental tests, placing a conservative upper limit of 190 K on the energy of the proposed topological defects known as visons. There is still debate about the extent to which this experiment can settle the issue of spin-charge separation in the high-Tc copper oxides, because some forms of the separation are able to avoid the need for visons. But at least one class of theories that all predict a vortex-memory effect now are unlikely models for the copper oxides.

Journal Article↗
PubMedDate not supplied

Buspirone inhibits contact hypersensitivity in the mouse.

We have observed that 8-4-[4-2-pyrimidyl)-1-piperazinyl]butyl]-8-azaspiro [4.5]decane-7.9-dione, an agent commonly known as buspirone HCl, possesses immunosuppressive activity when administered either topically or systemically, as assessed in a mouse model of contact hypersensitivity. Topical or systemic administration of buspirone significantly reduced the tissue swelling and leukocyte infiltration associated with the elicitation phase of contact hypersensitivity. Buspirone is a safe, widely used drug which has a history of use in humans throughout the world. These data demonstrate a previously unknown pharmacologic activity of buspirone.

Animals↗
PubMedDate not supplied

Mortality, morbidity, length and cost of hospitalization in very-low-birth-weight infants in the era of National Health Insurance in Taiwan: a medical center's experience.

The impact of implementation of the National Health Insurance on the outcome, cost, and length of hospitalization of very-low-birth-weight (VLBW) infants is not clear in Taiwan. These data are important for the planning of medical care and regionalization in this area. This study was an attempt to examine these questions. We retrospectively collected mortality, morbidity, and length and cost of hospitalization data of VLBW (BW < 1500 g) infants between March 1995 and February 1998. There were totally 162 patients enrolled. The overall mortality rate was 21.6%; the birth weight (BW)-specific mortality rate was 72%, 31%, 19%, and 3% for infants with BWs of < 750 g, 750-999 g, 1000-1249 g, and 1250-1499 g, respectively. The incidence of morbidities were: respiratory distress syndrome (74%), patent ductus arteriosus (36%), necrotizing enterocolitis (9%), sepsis (42%), intraventricular hemorrhage (15%), retinopathy of prematurity (31%), failure to pass auditory brainstem response (ABR) (34%), and chronic lung disease (17%). The average length of hospitalization was 67.2 days, and the cost per infant was 62 x 10(4) NT dollars; 108 +/- 38 days, 73 +/- 32 x 10(4) NT dollars if BW < 750 g; 94 +/- 15 days, 99 +/- 35 x 10(4) NT dollars if BW 750-999 g; 66 +/- 23 days, 64 +/- 36 x 10(4) NT dollars if BW 1000-1249 g; and 43 +/- 14 days, 39 +/- 37 x 10(4) NT dollars if BW 1250-1499 g. In conclusion, VLBW infants are associated with high mortality and morbidity rates. They have long lengths and high costs of hospitalization, and therefore deserve attention in the implementation of the National Health Insurance and regionalization.

Hospital Costs↗
PubMedDate not supplied

Atlantoaxial subluxation and syringomyelia in Down syndrome: report of one case.

Atlantoaxial instability is a relatively frequent finding in Down syndrome, but syringomyelia is a rare symptom. A four-year-old girl with Down syndrome was noted to have one year history of torticollis and progressive motor deterioration presenting with abnormal gait, ataxia or quadriparesis for the past three months. She was admitted because of acute urinary retention. Physical examination showed distended urinary bladder, hyperreflexia, bilateral ankle clonus and the existence of Babinski's signs. The x-ray films of the cervical spine showed widening between the joint space of atlas and odontoid processes. Magnetic resonance imaging revealed C1-C2 subluxation with syringomyelia. After bladder training and cervical orthosis, the symptoms improved.

Atlanto-Axial Joint↗
PubMedDate not supplied

Outcome and cost of intensive care for very low birth weight infants.

Very low birth weights (VLBW) remain the major factor contributing to neonatal mortality and morbidity. The development of Neonatal Intensive Care Units (NICU) has improved the outcome for the VLBW infants. However, outborn VLBW infants may have different outcomes, and different medical costs than those born intramurally. This study compared the mortality, morbidity and costs of inborn and outborn VLBW infants cared in the NICU of a tertiary care center. A total of 176 VLBW infants (inborn 83, outborn 93) were examined over the three years period June 1990 to May 1993. The birth weights (1131 +/- 244 g vs 1133 +/- 255 g) and gestational ages (29.0 +/- 4.0 wk vs 28.9 +/- 3.0 wk) were not different between the two groups. However, the age of admission to our wards was significantly different between the inborn infants (5.0 +/- 3.2 hr.) and outborn infants (53.6 +/- 26.8 hr.). There was no difference in mortality rates between the outborn infants (35.7%) and the inborn infants (32.9%), nor in the incidence of intraventricular hemorrhage, respiratory distress syndrome, sepsis, necrotizing enterocolitis, retinopathy of prematurity or abnormal auditory brainstem response. However the incidence of patent ductus arteriosus and chronic lung disease of the outborn infants was higher than those of the inborn (47% vs 32%, 51% vs 29% respectively). The mean duration of hospitalization and cost seemed to be longer and higher in the outborn VLBW infants. It was concluded that outborn VLBW infants have higher rates of morbidity, longer hospitalization and cost more than inborn infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Health Care Costs↗
PubMedDate not supplied

Refractory fetal supraventricular tachycardia with hydrops: report of one case.

Fetal tachycardia sometimes is quite difficult to treat, especially when the fetus has congestive heart failure. Sustained supraventricular tachycardia and hydrops had been diagnosed in a fetus as early as the 27th week of gestational age. A variety of antiarrhythmic agents, including digoxin, digoxin in combination with quinidine or propranolol or verapamil, have been prescribed for the mother, always in a vain effort of conversion of the tachycardia. A baby was born via vaginal delivery at 35 weeks' gestation because of premature labor. The tachycardia disappeared immediately after birth, but several episodes of tachycardia occurred during the neonatal period, and were converted only by electric cardioversion or intravenous amiodarone. Oral amiodarone was then prescribed for three months to prevent recurrence. The baby has lived well without attacks during a one-and-a-half-year follow-up.

Adult↗
PubMedDate not supplied

Renal effects and urinary excretion of prostaglandin following indomethacin therapy in premature infants with patent ductus arteriosus.

Renal side effects and urinary prostaglandin were evaluated in 10 premature infants (Mean +/- SD: BW 1245 +/- 290 gm, GA 32 +/- 2.2 wks, Postnatal age 7.7 +/- 3.8 days) with significant PDA who were given one dose of indomethacin (0.3 mg/kg intravenously). There was a significant decrease in urinary output, osmolal and free water clearance after therapy. The fractional excretion of sodium, chloride, potassium, glomerular filtration rate and urinary prostaglandin E2 also decreased but were not statistically different from the baseline values. In infants who responded to indomethacin with ductus closure, their renal functions appeared to be preserved even though they had higher plasma indomethacin levels than the non-responders in whom significant changes in renal function were observed following indomethacin therapy. This observation suggested that the improved renal hemodynamics following the closure of the ductus may minimize or attenuate the renal side effects of indomethacin.

Ductus Arteriosus, Patent↗
PubMedDate not supplied

Coronavirus: how a large RNA viral genome is replicated and transcribed.

Coronaviruses are important human and animal pathogens and contain an extraordinarily long (27-31 kb) RNA genome. Its RNA synthesis involves complex mechanisms of regulation, similar to those of DNA viruses. In this treatise, mouse hepatitis virus (MHV) is used as a model for the discussion of the mechanism of viral RNA synthesis. We show that MHV RNA synthesis requires interactions of multiple RNA components, which are likely mediated by protein-RNA and protein-protein, as well as RNA-RNA, interactions. This virus also provides a unique example of a discontinuous transcription mechanism, which involves a trans-acting RNA component. Finally, study of the cis-acting signals for the various steps of RNA synthesis revealed an insight into the regulation of viral RNA synthesis. This discussion suggests that the regulation of RNA synthesis in coronavirus is more complex than previously thought possible for RNA viruses. Coronavirus RNA transcription and replication may serve as a paradigm of RNA synthesis for RNA viruses in general.

Animals↗
PubMedDate not supplied

The clinical application of transcutaneous bilirubinometry in full-term Chinese infants.

The pattern of jaundice in Chinese full-term newborns has seldom been explored. This study was to 1) investigate the correlation between transcutaneous bilirubin indices (TcB) and serum bilirubin levels; 2) use TcB to follow the pattern of jaundice in Chinese full-term newborns; and 3) compare the sensitivity and specificity of TcB measured from the forehead (TcB1), and mid-sternum (TcB2) by receiver operating characteristic curves (ROC curves). From April 1 to August 31, 1989, a total of 3217 TcB were obtained from 305 inborn full-term newborns (male 175, female 130) during their first 6 days of life. The correlation between serum bilirubin levels and TcB measured from the forehead (TcB1) and from the mid-sternum (TcB2) was good (r = 0.82 and 0.86 respectively). For formula-fed infants, both TcB1 (16.3 +/- 3.0) and TcB2 (16.6 +/- 2.7) reached peak levels at 78-84 hours of age, while in mixed-fed infants, peak levels were noted at 54-60 and 84-90 hours for TcB1 (17.2 +/- 2.2) and TcB2 (16.6 +/- 2.6) respectively. The incidence of hyperbilirubinemia was 5.9 per cent. There were no differences in peak TcB levels between formula-fed and mixed-fed infants. The ROC curves suggested that TcB2 is better than TcB1 in sensitivity and specificity. It is concluded that TcB is a reliable device for monitoring jaundice in Chinese full-term newborns. Peak level of jaundice occurred at the third to fourth day of age. The incidence of hyperbilirubinemia in Chinese infants has decreased, for reasons which need further investigation.

Bilirubin↗
PubMedDate not supplied

Prevalence of Legionella pneumophila infection in children and its role in pediatric community-acquired atypical pneumonia.

The infection status of Legionella pneumophila in children and its role in pediatric community-acquired pneumonia were investigated. Because exposure to Legionella pneumophila may be highly variable and there has been no unanimously agreed-upon cut-off values in previous seroprevalence studies, 60 serum samples collected from infants aged 12 to 18 months were examined using immunofluorescence antibody test to determine the cut-off titer which represents past Legionella pneumophila infection. An IFA titer of greater than or equal to 32 was found to be suitable to represent past L. pneumophila infection. A seroepidemiological study of the prevalence of L. pneumophila in 180 children showed the prevalences in children aged 7 to 18 years to be between 28.4 and 35%. Fifty-three paired sera were tested to determine the role of Legionella pneumophila in pediatric, community-acquired, atypical pneumonia. The frequency of confirmed disease was 0% and of presumptive cases was 5.7%. Legionella pneumophila was not a common etiologic agent of pediatric pneumonia in Taiwan.

Adolescent↗
PubMedDate not supplied

Systemic fungal infection in very low-birth-weight infants.

This retrospective study was designed to investigate the related factors and outcome of systemic fungal infection in very low-birth-weight (VLBW) infants. Medical records of infants admitted to the neonatal intensive care unit of National Cheng Kung University Hospital between January 1990 and June 1994 were reviewed. Of the 262 VLBW infants, 15 (5.7%) had fungemia (14 Candida 1 Cryptococcus) during the study period. Among the fungemic infants, 60% also had urinary tract infection; 18% had central nervous system infection. Their mean birth weight was 1079 +/- 78 g (504-1474 g), and the gestational age was 28.6 +/- 0.6 weeks (23-32 weeks). Thirteen of them (87%) had respiratory distress syndrome and patent ductus arteriosus, while 60% had chronic lung disease. The percentage of antibiotic usage, parenteral hyperalimentation, endotracheal intubation, placement of central venous line and steroid therapy were 100%, 100%, 73%, 67% and 36% respectively. The mean age at diagnosis of fungemia was 40.5 +/- 4.8 days (10-76 days). Common clinical manifestations were respiratory deterioration (93%), poor feeding (58%) and fever (53%). The frequency of side effects of amphotericin B in decreasing order were: hypokalemia (54%), hyponatremia (31%) and decreased urine amount (23%). The mortality rate was 40%. It was concluded that systemic fungal infection in VLBW infants might result in high mortality and the side effects were high in the treated infants.

Amphotericin B↗
PubMedDate not supplied

A seroepidemiological study of Varicella-Zoster virus in Taipei City.

Varicella has been considered a common and benign disease of children. However, adults tend to have severe disease and in some high risk groups, such as neonates and leukemic patients, varicella infection can be fatal. A large-scale seroepidemiological study on varicella was performed to reveal the current varicella infection status and to serve as a prevaccination survey before the possible implementation of vaccination program in Taiwan. This study included a total of 1384 individuals whose ages ranged from newborns to old adults. Enzyme-linked immunosorbent assay was adopted to determine the IgG antibodies against Varicella-Zoster virus. The results showed: (1) only 24% of infants aged birth to three months had maternal antibodies, (2) the seroprevalence increased slowly during the first 3 years after birth, (3) most infections occurred between 3 and 10 years old, (4) 10% (female) to 20% (male) of adults were still susceptible to varicella infection, and (5) 85% of pregnant women had antibodies against VZV. These data suggest that if varicella vaccination is to be done in Taiwan, the appropriate inoculation age would be between 12 and 24 months. Besides, there exists a pool of uninfected adults who potentially will develop severe illnesses once infected and should be screened and protected by varicella vaccines.

Adolescent↗
PubMedDate not supplied

K-ras gene mutation is a useful predictor of the survival of early stage colorectal cancers.

Mutations in the K-ras gene were found to be of predictive value in the clinical outcome of non-small cell lung cancers, but its role in predicting the survival of colorectal cancer patients is still inconclusive. Point mutations in codon 12 or 13 of K-ras gene were analyzed in 64 colorectal cancers composing 4 Dukes' stage. A, 34 stage B, 21 stage C and 5 stage D. DNA extracted from the paraffin-embedded tissues of the 64 patients was amplified with the polymerase chain reaction and subsequently analyzed by direct cycle sequencing. Thirteen of sixty-four (20%) resected colorectal cancer specimens were found to have K-ras gene mutation at either codon 12 or 13. Log rank tests found that K-ras gene mutation and Dukes' stage were associated with patients' survival. When stratified by Dukes' stage, the patients with mutated K-ras genes in the stratum of stage A or B were found to have shorter survival times than those without mutated K-ras genes (P = 0.003), but this was not the case in the stratum of stages C and D. The relative risk of mortality in the stratum of stage A or B was 7.74 (95% confidence interval: 1.72-34.89) by Cox regression analysis. We thereby conclude that K-ras gene mutation is a usefull predictor of the survival of early stage colorectal cancers.

Adult↗