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Biomedical subjects

T Chiu

Publications and source records attributed to T Chiu.

At least 37 records · Page 2Linked to original sources
PubMed1988

Chronic inhalation toxicity/carcinogenicity study in rats exposed to fluorocarbon 113 (FC-113).

Groups of 100 male and 100 female Crl:CDBR rats were exposed by whole-body inhalation to FC-113 (1,1,2-trichloro-1,2,2-trifluoroethane) for 6 hr a day, 5 days a week for 24 months. Average exposure concentrations (+/- 1 SD) were 0.0 (control), 2000 +/- 100, 10,000 +/- 500, and 20,000 +/- 1000 ppm (v/v), respectively. Body weights were consistently lower in both male and female rats in the 20,000 ppm exposure group after approximately 1 and 4 months' exposure, respectively, and in female rats after 12 months' exposure at 10,000 ppm. Observations of appearance and behavior, mortality, and clinical laboratory measurements were unremarkable during the 24-month exposure period. Despite exposure levels as high as 20,000 ppm, only occasional slight increases in urinary fluoride were seen. Microscopic examination of tissues from rats examined during and at the end of the 24-month study revealed no evidence of compound-related toxicity or carcinogenicity. Based mainly on a 5 to 10% decrease in body weight gain at the 10,000 and 20,000 ppm exposure levels, the no-observed-effect level for FC-113 in this study was 2000 ppm.

Adenoma↗
PubMed1987

A correlative study on the embryotrophic property of patient's serum and the outcome of in vitro fertilization of human oocytes.

The embryotrophic property of patient's serum previously used for in vitro fertilization (IVF) was studied by culturing postimplantation organogenesis-stage mouse embryos in a medium containing equal parts of Dulbecco's modified Eagle's medium and the patient's serum. Results of embryo culture experiments were generally found to correlate well with the outcome of IVF. Serum of patients whose oocytes were fertilized and developed to cleavage-stage embryos scored highest for embryotrophic parameters such as morphologic score and protein content of the mouse embryo. There was no significant difference in terms of serum embryotrophic activity between patients who became pregnant after embryo transfer and those who did not. When mouse embryos were cultured in serum from cycles with poor IVF results, i.e., oocytes failed to be fertilized or fertilized oocytes failed to cleave or cleave abnormally, significantly retarded embryonic growth and a higher incidence of malformed embryos were observed. However, in two cases where IVF failed as a result of poor semen quality, the patient's serum was found to be supportive of mouse embryonic development.

Animals↗
PubMed1987

Focal eosinophilic hypertrophic cells of the rat pancreas.

Focal spontaneously occurring eosinophilic hypertrophic cells, histomorphologically resembling oncocytes and hepatocytes, were observed in the pancreas from 11 (0.3%) of 4,177 Sprague-Dawley rats, 3 to 26 months old. The age of these eleven rats ranged from 13 to 25 months. The incidence was not different between sexes. The altered cells were usually seen in the peri-insular area. Two types of foci, uniform and pleomorphic, were classified on the basis of uniformity of size of the altered cells within a focus. The origin and nature were not determined for the altered cells/foci reported in this study but they were not considered to be neoplastic.

Animals↗
PubMed1987

A comparison of the transabdominal and transvaginal methods of ultrasound-guided aspiration of pre-ovulatory oocytes for in vitro fertilisation.

The efficiency of two methods of ultrasound-guided aspiration of pre-ovulatory oocytes was compared in 238 treatment cycles, of which 166 were by the transabdominal-transvesical (TA) route and 72 by the transvaginal (TV) route. Successful collection of at least one oocyte was achieved in 86% of TA attempts and in 97% of TV attempts. Significantly less oocytes were collected from follicles by the TA methods than by the TV methods: 374 oocytes were obtained from 797 follicles (46% recovery) and 242 oocytes from 338 follicles (72% recovery), respectively. Although fertilisation occurred more frequently in TA-recovered oocyte (70% versus 54%), the incidence of cleavage per inseminated oocytes collected by these TA and TV methods was similar (49% versus 44%, respectively). Results of this study therefore suggest that the TV method is superior to the TA approach for oocyte recovery.

Adult↗
PubMed1986

Spontaneous basophilic hypertrophic foci of the parotid glands in rats and mice.

Basophilic hypertrophic foci of the parotid glands characterized by focal hypertrophy and hyperchromasia of acinar cells was seen in Sprague-Dawley rats and Swiss mice with overall incidences of 4.8% (102/2,138) and 0.6% (4/723), respectively. In rats, the incidence increased significantly with age, but the size and number of the lesions per rat did not. Based on the similar incidence in both control and treated animals, lesions were considered to be spontaneous. Their morphology and growth pattern suggested that they were neither degenerative, necrotic, hyperplastic/preneoplastic, nor neoplastic, but, that they are a distinct pathologic entity of a nature not yet determined.

Aging↗
PubMed1985

Hypertrophic foci of pancreatic acinar cells in rats.

A morphologically distinctive type of pancreatic acinar cell foci, different from hyperplastic nodules and adenomas, in rats has been recognized for two decades. The lesions have been observed to occur spontaneously and to be induced experimentally. They consist of enlarged acinar cells with abundant cytoplasm of altered staining characteristics and prominent nuclei. There is, however, a wide divergence of opinion among investigators regarding the nature of the lesions. As a result of different interpretations and classifications, many terms have been given to them. Based on morphologic characteristics, the author has designated the lesions as hypertrophic foci, a descriptive morphological term. The biologic significance with particular reference to age and the relationship with acinar cell neoplasia is discussed. Also included in the review are similar lesions in other rodent species.

2-Acetylaminofluorene↗
PubMed1984

Auricular chondropathy in aging rats.

An external ear lesion designated as auricular chondropathy in aging Crl:CD rats was reported. One hundred eighty (180) of 4,876 rats (3.7%) had ear deformity. Grossly, the ears were thickened, nodular, or disfigured. Both ears were affected in most rats. The lesions primarily involved the cartilaginous plate and were associated with two processes--chondrolysis and granulomatous inflammation. The detailed morphogenesis of the lesions is described, but the etiology of the lesions is unknown. Auricular chondropathy in rats and relapsing polychondritis in man are compared.

Animals↗
PubMed1984

Clinical evaluation of mezlocillin in neonates.

Single-dose pharmacokinetic studies were performed in 64 infants, ranging in age from less than 1 day to 6 days, after intravenous infusion or intramuscular injection of approximately 75 mg/kg of mezlocillin. Mean serum concentrations at one hour were 107 micrograms/ml and 82.5 micrograms/ml for neonates less than or equal to 1 day of age and greater than or equal to 6 days of age, respectively. The serum clearance ranged from 3.0 to 6.4 hours. Based on data from the study, it is recommended that mezlocillin be administered to neonates with gram-negative bacterial infections in a single dose of 75 mg/kg, either as an intravenous infusion over 30 minutes or as an intramuscular injection, every 12 hours during the first week of life. Mezlocillin alone or in conjunction with penicillin was used in treating 165 neonates with suspected sepsis. Gram-negative organisms were recovered from 18 of the 27 neonates from whom pathogens were isolated. Three of these 18 strains, a Klebsiella oxytoca, an Acinetobacter anitratum, and a Haemophilus influenzae, were resistant to mezlocillin in vitro. Twenty-four of the 27 patients who satisfied criteria for evaluation achieved a bacteriological and a clinical cure. Cerebrospinal fluid permeation after multiple doses ranged from 18% to 45% of serum levels. No significant local or systemic side effects were seen. The results indicate that mezlocillin is an effective ureidopenicillin for the treatment of gram-negative bacterial infections.

Bacterial Infections↗
PubMed1984

Megakaryocytes with intracytoplasmic blood cells.

The phenomenon of megakaryocytes containing intracytoplasmic blood cells was frequently observed in the bone marrow of rats. The frequency appeared to increase in inflammatory or neoplastic conditions. The types of blood cells engulfed were mainly neutrophils. For the first time, megakaryocytes also were found to be engulfed.

Animals↗
PubMed1983

Spontaneous hypertrophic foci of pancreatic acinar cells in CD rats.

A study was conducted to determine the spontaneous occurrence of hypertrophic foci of the pancreatic acinar cells in rats. Tissues from untreated control rats, 4 to 27 months of age and used in either subchronic and chronic feeding toxicity or carcinogenicity studies were reviewed. The lesions, morphologically distinctly different from nodular hyperplasia or hyperplastic nodules and adenomas, were microscopic in size and occurred in 109 of 607 males (17.6%) and 87 of 517 females (16.8%). The overall incidence of hypertrophic foci in the pancreas from rats of both sexes significantly increased with age. The lesion was not sex-related. Neither the size nor the number of lesions appeared to increase with age. The lesion represents a distinct pathologic entity and is considered to be neither hyperplastic nor neoplastic.

Animals↗
PubMed1982

Neonatal coronary thrombosis.

We have described a case of coronary thrombosis in a neonate. The diagnosis should be considered in a term infant who presents with a shock-like state with poor perfusion soon after birth. The chest roentgenogram may vary from a normal pattern to generalized cardiomegaly with pulmonary congestion. The electrocardiogram may show a pattern varying from severe right ventricular hypertrophy to anterior left myocardial injury. Prognosis is usually poor, and the infant may die within 24 hours after delivery. The etiology of the thrombus formation remains obscure.

Coronary Disease↗