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Biomedical subjects

T Tsai

Publications and source records attributed to T Tsai.

At least 37 records · Page 2Linked to original sources
PubMed1995

Adsorption of salmon calcitonin to PLGA microspheres.

PURPOSE: The interaction of salmon calcitonin (sCT) and poly (d,l-lactide-co-glycolide) was detected during preparation and evaluation of microspheres. The purpose of this study was to quantitate the extent and nature of the interaction. METHODS: Blank microspheres were prepared by an aqueous emulsification solvent extraction technique. Adsorption studies were carried out at six concentrations of sCT and three concentrations of microspheres. Adsorption isotherms were constructed using the Langmuir and Freundlich treatments. RESULTS: Adsorption at 1 mg/ml sCT concentration resulted in almost complete depletion of the peptide from the adsorption medium with the time to reach maximum adsorption decreasing with increasing microsphere concentration. At sCT concentrations below 100 micrograms/ml, a true equilibrium occurred in 1 hour or less while at higher concentrations (up to 350 micrograms/ml), a transient equilibrium was reached in 1 to 2 hours, followed by further adsorption of the peptide. The adsorption followed the Langmuir isotherm at concentrations below 200 micrograms/ml, indicating formation of a monolayer. Multilayer interaction, described by the Freundlich isotherm, occurred at higher concentrations and resulted in complete depletion of sCT from the adsorption medium. The affinity constant during monolayer formation was 0.09 and the plateau surface concentration was 5.1 micrograms/mg. The multilayer peptide-peptide adsorption showed a lower affinity (0.025) but higher capacity (24 micrograms/mg) than the monolayer peptide-polymer adsorption. CONCLUSIONS: The results show that poly (d,l-lactide-co-glycolide) microspheres have a high adsorption capacity for sCT which must be considered in formulating a controlled delivery product of this peptide.

Adsorption↗
PubMed1994

Comparison of proximal and distal one portal entry techniques for endoscopic carpal tunnel release. A cadaver study.

Reported complications of endoscopic carpal tunnel release have increased as more surgeons use this technique to release the flexor retinaculum. We used a cadaver model to compare the results of endoscopic carpal tunnel release through a one-portal distal (Group A, 15 specimens) and a one-portal proximal (Group B, 15 specimens) entry site with a new endoscopic technique. Our custom-made glass tube of three different sizes (5, 7, and 9 mm in diameter) is designed to house an endoscope and accommodate a meniscus knife for releasing the flexor retinaculum. Complete release of the flexor retinaculum was obtained in all limbs in both groups. In Group A the one complication (7%) was loss of the cotton tip from the cotton swab stick within the carpal tunnel. In Group B, there was a single case of injury to the superficial palmar arch in one hand and breakage of a glass tube in another hand, for a total complication rate of 13%. No other damage to anatomical structures was noted.

Cadaver↗
PubMed1994

Cloning of a structural and functional homolog of the circadian clock gene period from the giant silkmoth Antheraea pernyi.

The period (per) gene of Drosophila plays an important role in circadian clock function. Interestingly, homologs of per have not been cloned outside of dipteran species. Using a PCR strategy, we now report the cloning of the cDNA of a per homolog from the silkmoth Antheraea pernyi. The cDNA encodes a protein of 849 amino acids, which shows highest identity (39%) with the per protein of Drosophila virilis. Stretches of high identity between moth and fly proteins are in the amino terminus, the PAS region, and the region surrounding the site of the per mutation in Drosophila. Moth per homolog mRNA levels exhibit a prominent circadian variation in adult heads, and per protein antibodies show a pronounced variation of per antigen staining in photoreceptor nuclei. With sequence information derived from moth and flies, per-like cDNA fragments were readily cloned by PCR from other moth species and a third insect order.

Amino Acid Sequence↗
PubMed1992

St. Louis encephalitis in Arkansas.

The first outbreak of St. Louis encephalitis (SLE) in Arkansas occurred in Pine Bluff (Jefferson County) during July-August 1991. Cases of SLE were identified mainly through reporting by physicians in Jefferson and surrounding counties. In addition, testing of stored cerebrospinal fluid specimens, a hospital chart review, and a serosurvey were performed in Pine Bluff. Twenty-eight Arkansas residents, five of whom died, had cases of SLE. Half the case patients were over age 60, and nearly half had hypertension. The serosurvey confirmed that infection with the SLE virus was not new to Pine Bluff, and that most infections in 1991 were asymptomatic. Arkansas physicians may see more cases of SLE in 1992. SLE epidemiology, clinical presentation, diagnosis, and preventive measures are reviewed.

Adolescent↗
PubMed1979

A complex reimplantation of digits: a case report.

In multiple finger amputations, microsurgical reconstruction should concentrate on the thumb, index, and middle fingers. The patient in the case report presented in this paper initially sustained an amputation of all of the digits on the left hand and an amputation of the right thumb. Both thumbs were amputated at the metacarpophalangeal joint. Initial replantation of the left thumb, index, and middle fingers and of the right thumb was carried out. The right thumb replantation failed and, after healing, the right great toe was transferred to the right hand. Subsequent to this, the patient developed useful function of all reconstructed digits. Twenty-one months after the first injury, both thumbs sustained new traumatic amputations 1.0 cm distal to the previous amputations. Both thumbs were replanted again successfully.

Accidents, Occupational↗
PubMed1978

Epidemic Yersinia enterocolitica infection due to contaminated chocolate milk.

In September and October, 1976, an outbreak of illness due to chocolate milk contaminated with Yersinia enterocolitica resulted in hospitalization of 36 children, 16 of whom had appendectomies. Infection with Y. enterocolitica serotype 0:8 was demonstrated in 38 ill persons. Sixty-one per cent of the persons who were infected had a titer greater than 1:160 OH agglutinins to serotype 8 yersinia, whereas 48 per cent of the hospitalized children had a fourfold change in agglutinin titer. An epidemiologic investigation demonstrated that illness was associated with drinking of chocolate milk purchased in school cafeterias, and Y. enterocolitica 0:8 was subsequently isolated from the milk. The investigation suggested that the bacterium was introduced at the dairy during the mixing by hand of chocolate syrup with previously pasteurized milk.

Adolescent↗
PubMed1977

Fatal ECHO 24 infection in a patient with hypogammaglobulinemia: relationship to dermatomyositis-like syndrome.

Patients with deficient antibody-mediated immunity may develop a rare "dermatomyositis-like" syndrome, which is usually progressive and fatal. We have observed a child with hypogammaglobulinemia in whom a dermatomyositis-like syndrome was associated with a fatal, disseminated ECHO 24 infection. This association suggests that in some immunodeficient patients the fatal dermatomyositis-like syndrome is a manifestation of a viral infection in a compromised host. The use of maternal plasma, with a high titer of ECHO 24 neutralizing activity, was unsuccessful in arresting the progress of the infection.

Agammaglobulinemia↗
PubMed1976

Effect of altered lighting regimens, time-limited feeding, and presence of Ehrlich ascites carcinoma on the circadian rhythm in DNA synthesis of mouse spleen.

The objectives of the series of experiments described were (a) to determine whether there was a circadian rhythm in the incorporation of tritiated thymidine into DNA of the spleen in mice kept on a conventional light-dark cycle and fed ad libitum, (b) to study the effect that different light-dark cycles and a time-limited feeding schedule had on this circadian rhythm, (c) to ascertain what effect the presence of an 8-day Ehrlich ascites carcinoma (EAC) had on the rhythm in DNA synthesis in the spleen and what effect the EAC had on the circadian rhythm in the mitotic index in the corneal epithelium, and (d) to determine whether there was a circadian rhythm in the duration of life-span in mice bearing the EAC. A circadian rhythm in the incorporation of tritiated thymidine into DNA of the mouse spleen consistently was characterized by a peak during the nocturnal phase and a trough during the diurnal phase of the 12-hr light-12-hr dark cycle. In animals bearing an 8-day EAC, the rhythm in DNA synthesis in the spleen was phase-shifted, its wave form was changed, and the overall 24-hr mean was increased significantly. The phasing of the rhythm in EAC-bearing mice was not reproducible. This finding demonstrated that the presence of the EAC severely altered the natural rhythm in DNA synthesis in the spleen and resulted in a rhythmic pattern which was constantly changing. The presence of an 8-day EAC, however, had no effect on the amplitude, overall level, or the phasing of the circadian rhythm in the mitotic index in the cornea. A staggered light-dark cycle of 2 weeks duration did not completely phase-shift the DNA synthesis rhythm in the spleen but did completely phase-shift the rhythm in the mitotic index in the corneal epithelium. In mice subjected to a daily feeding period limited to 4 hr, the rhythm in DNA synthesis in the spleen, in both EAC-bearing and non-EAC bearing mice, was phase-shifted such that the peak occurred during the time of feeding and the trough occurred prior to the feeding period. The rhythm in the mitotic index in the cornea was not phase-shifted or altered in any way by the feeding schedule and thus remained fixed to the light-dark cycle. The DNA synthesis rhythm in the normal spleen demonstrated a phasing very similar to the circadian rhythm in the length of survival in mice challenged with EAC and the circadian rhythm in DNA synthesis in the normal thymus.

Animals↗
PubMed1975

Seroepidemiology of human papovaviruses. Discovery of virgin populations and some unusual patterns of antibody prevalence among remote peoples of the world.

A total of 1544 sera from 28 diverse and mainly isolated populations were examined for HI antibody to BK virus. A few extremely isolated populations were found with negligible or absent exposure to the virus, but in most populations, remote or cosmopolitan, antibody appeared in increasing prevalence during early childhood and remained stable throughout adult life. Antibody acquisition and prevalence rates in individual families reflected that of the general population. Examined for HI antibody to JC virus were 393 sera from 9 of the 28 populations. Age acquisition and prevalence rates of antibody were similar to those of BK virus, but experience with the 2 viruses was found to occur independently in several population groups, i.e., high exposure to BK with low exposure to JC, or vice-versa. Examined for neurtralizing antibody to SV40 were 151 sera with and without BK HI antibody in individuals from several primitive populations. SV40 antibody, mainly in low titer, occurred in 35% of the BK-positive group, but only 5% of the BK-negative group, suggesting that infection with BK or a closely related virus is responsible for antibody directed against SV40 in most humans unexposed to known vaccine or monkey sources of SV40 infection.

Adolescent↗
PubMedDate not supplied

Intrathecal baclofen pump use for spasticity: a clinical survey.

OBJECTIVE: To obtain information from continuous intrathecal baclofen infusion (CIBI) pump centers regarding specific clinical practices and experiences. METHODS: A total of 115 centers were surveyed by mail. RESULTS: Forty centers (35%) responded with information about 1,002 test doses and 936 pump placements. Patient diagnoses included cerebral palsy, spinal cord injury, traumatic brain injury, and others. The average test dose was 50 microg. A total of 87% of trials were successful. The most common test dose complications were nausea/vomiting (2.6%) and sedation (2.2%). Pump placement complications included cerebrospinal fluid (CSF) collection (3.3%), constipation (2.9%), headache (2.4%), and CSF leak (2.2%). The most common long-term complications were catheter kink or migration (4%) and infection (1.2%). Improved daily activities including easier diapering, dressing, transfers, orthotic wear and comfort, and sitting tolerance were reported in the majority (>90%) of patients. Mixed results were reported for oral motor function and head, bladder, and bowel control. CONCLUSIONS: CIBI is an effective treatment for severe spasticity, with dramatic quality-of-life improvements and a small number of significant complications. Long-term benefits and complications need to be monitored in this complex population.

Baclofen↗