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Biomedical subjects

T J Chen

Publications and source records attributed to T J Chen.

At least 109 records · Page 6Linked to original sources
PubMed1990

Study of morphology and deciduomal proteins of hamster endometrial cells during in vitro decidualization.

The objective of this study was first, to examine whether the morphological characteristics of deciduomal cells are correlate to differentiation or just to hyperplasia and hypertrophy, and second, to examine whether the deciduoma-associated proteins (DAPs) are expressed consistently during decidualization in vitro and in vivo. In vitro decidualization was implemented by dissociated cell culture of Day-4-pseudopregnant endometrium. The morphology of these cultures was compared with that of undifferentiated cultures of fetal hamster fibroblast. They appeared similar morphology in the stellate shape, the binucleation and the intracellular fibers. The DAPs were identified by comparing the electrophoretic maps of one-day cultures of decidualized and nondecidualized endometrium from unilaterally scratched Day-6-pseudopregnant animals. Analysis of cytosol fraction by SDS-PAGE demonstrated the presence of four DAPs. That only one of them was growth-associated, which was concluded from its increasing expression in fetal fibroblast, and that all of them were not endometrium-specific as evidenced by their presence in other tissues. By examining their expression during in vitro decidualization, we found that timing of the DAPs' expression in vitro was not consistent with it in vivo. These results indicate that some morphological characteristics which were accustomedly used to mark deciduomal cells may relate to hyperplasia and hypertrophy instead of differentiation, and that the in vitro and the in vivo decidualization are not identical.

Animals↗
PubMed1990

Alterations of brain stem auditory evoked potentials in hypothermia.

Brain stem auditory evoked potentials (BAEPs) were studied as a criterion for evaluating hypothermic effects on the brainstem in rats. Eleven adult male Long-Evans rats were cooled slowly from 37 degrees C to 25 degrees C by an ice pad. BAEPs were recorded at intervals of every 1 degree C of change, and both central and peripheral acoustic conductions were assessed. As the body temperature decreased, latencies significantly increased, with the most prominent effect at the higher brainstem level. Interpeak latencies were prolonged also, while the reverse occurred with warming. These data agree with previous studies in other animals and men. However, during analysis of the effects of hypothermia on the brain stem auditory pathway, it was shown that these hypothermic effects were equally distributed throughout the whole pathway in the present study, rather than being emphatic in the proximal portion only. Greater prolongation of latencies in the proximal portion was caused by a cumulative effect from the distal peaks. Recovery was attained completely after rewarming and subsequent survival. Under extreme hypothermia, BAEPs disappeared gradually with apnea and cardiac arrest; however, resuscitation and rewarming saved the rats. In addition to wishing to make conventional observations, the present study sought to recognize the section of the acoustic pathway most sensitive to hypothermic effects and interpret the outcome after hypothermia treatment.

Animals↗
PubMed1989

Hepatocellular carcinoma presenting as bone metastasis.

In a consecutive series of 395 patients with pathologically verified hepatocellular carcinoma, 20 patients (5%) had bone metastasis at initial presentation. Of these, 16 were men and four women ranging from 26 to 64 years of age (median, 50 years). The age, sex, hepatitis B surface antigen seropositivity, alpha-fetoprotein level, and frequency of associated cirrhosis were not statistically different from those in patients without initial bone metastasis. Initial presentation was usually the result of spinal lesion with neurologic compression, and chest wall or scalp mass. Metastasis most commonly involved spine and ribs, and occurred as osteolytic lesions or extrapleural mass. Computed tomography proved best for demonstrating an expansile soft tissue mass with bony destruction. Angiography showed hypervascular appearance over the destructive bone area. Treatment results were poor. The follow-up period ranged from 3 weeks to 14 months with a median survival of 5 months. The data suggested that hepatocellular carcinoma be ruled out in patients with osteolytic lesions.

Adult↗
PubMed1989

Natural course of patients with chronic type B hepatitis following acute hepatitis delta virus superinfection.

A 6-96-month prospective follow-up study on the natural course of chronic type B hepatitis after contracting acute hepatitis delta virus (HDV) superinfection was conducted in 30 patients with clear-cut onset of acute HDV superinfection (HDV group). Thirty patients with acute exacerbation without evidence of HDV infection, and well matched in terms of age, sex and hepatitis B e antigen/antibody status, served as the control group. The clinical and biochemical presentations tended to be more severe in the HDV group. More patients in the HDV group had persistent abnormal liver biochemical tests (69% vs 47%) and progressed to chronic active hepatitis (46% vs 20%) or cirrhosis (9.4%/year vs 5.2%/year), but the differences were not significant statistically. The results suggest that HDV superinfection induces slow progression of liver disease. However, in the early stage, the impact of HDV superinfection is not particularly different from that of the acute exacerbation unrelated to HDV in patients with chronic type B hepatitis.

Adult↗
PubMed1989

Natural course after the development of cirrhosis in patients with chronic type B hepatitis: a prospective study.

To examine the early stage of the natural course of liver cirrhosis, a prospective follow-up study was conducted in a series of 76 patients with recent development of cirrhosis during the course of chronic type B hepatitis. During a mean follow-up period of 34.4 months, 45 episodes of acute exacerbation were recorded; the majority of the episodes occurred within 2 years after entry. The calculated annual incidence of acute exacerbation was significantly higher in patients seropositive for hepatitis B e antigen (HBeAg) and/or hepatitis B virus (HBV)-DNA (25.9%) than in those without these markers (11.9%). Three-fourths of the acute exacerbations were attributable to the reactivation of HBV. Spontaneous HBeAg seroconversion to anti-HBe also occurred in the early phase, but less than 30% of the events were preceded by acute exacerbation. Late hepatitis B surface antigen clearance occurred in two patients. Hepatic decompensation, esophageal variceal bleeding and hepatocellular carcinoma developed relatively late in the course of the disease with a calculated annual incidence of 2.3%, 2.3% and 2.8%, respectively. Seven patients (9.2%) died of hepatic failure or variceal bleeding, usually more than 3 years after entry. The estimated 5-year survival rate was 80%. The results suggest that the natural events of chronic HBV infection, including exacerbation, seroconversion and its sequelae could occur after the development of cirrhosis. In addition, these events might be responsible for the clinicopathological changes and the outcomes of these cirrhotic patients.

Adult↗
PubMed1989

Deciduomal estrogen and progesterone receptors in unilateral pregnant hamsters.

Deciduomal reactions in response to artificial stimuli were induced on the tube-ligated uterine horns of unilateral pregnant hamsters. Serum progesterone levels were determined, and the changes of estrogen and progesterone receptors (ER and PR, respectively) were simultaneously studied in the deciduoma. After stimulation on day 4 of pregnancy (D4), the serum progesterone level rose steadily to about 16 ng/ml on D12 and remained at plateau until D14. A sharp increase followed by a rapid fall in progesterone was observed on D15 and D16. The weight of the deciduoma-bearing horn increased more than 5 times to a maximal level on D10. Both deciduomal and myometrial weights were maintained and remained elevated on D16. Histological observation revealed that the maintenance of decidual cells was heterogenous. Cells at antimesometrial site (AMS) started to regress on D10, whereas cells at mesometrial site (MS) remained recognizable on D16. Cytosol ER was detected during the early stage (D6) of decidualization. The cytosol ER in the deciduoma continuously decreased and became undetectable on D10. Nuclear ER was not detected during the time of study. The nuclear and cytosol PR increased and reached a peak level on D8 and D10, respectively. The concentration of PR declined sharply afterward. The PR levels in deciduomal tissues at MS and AMS were separately studied. PR in AMS decreased gradually after D8 to basal level on D14. PR at MS still remained relatively constant on D12 followed by a precipitous decrease. These data show a prolongation of the deciduomal life span and the heterogeneity of deciduomal maintenance and regression in unilateral pregnant hamsters. This strongly suggests a close relationship between the loss of PR and the regression of the deciduoma.

Animals↗
PubMed1989

Effects of estrogen on progesterone receptor synthesis during endometrial cell culture.

Endometrial cells from the hamster's uterus were grown as a monolayer during primary cell cultures and the progesterone receptor synthesis in the cultured cells was determined. The cells were found to be estrogen responsive. Production of the progesterone receptor in the cultured cells was enhanced by the presence of 17 beta-estradiol at physiological concentrations. A significant increase in specific binding of (3H) R5020 was observed after 24h of culture; by 48 h, a 2- to 3-fold augmentation in binding was noted. The increase in the progesterone receptor depended on the concentration of estradiol, with maximal response at about 1 nM. The progesterone receptor response was specific for estrogen. Testosterone or cortisol induced small or no response on the production of progesterone receptors. The progesterone receptor synthesis was inhibited by cycloheximide (10 micrograms/ml) or actinomycin D (10 micrograms/ml). These results demonstrate that endometrial cell cultures can serve as a good in vitro system for the study of hormonal effects on progesterone receptor synthesis or other biochemical responses. We conclude that the progesterone receptor formation in the cultured endometrial cells is mediated via RNA and protein synthesis.

Animals↗
PubMed1989

Multiple-hormone-producing islet cell carcinoma: report of a case.

Although part of pancreatic endocrine tumors may be multihormonal by immunohistochemical study, the clinical manifestations are often related to hypersecretion of only one type of peptide hormone. Only a few cases have shown two or more syndromes simultaneously or transition of one type of syndrome to another with the passage of time. The case reported here is an islet cell carcinoma with liver metastases. The clinical manifestations changed from Zollinger-Ellison syndrome to hypoglycemic syndrome with the secretion of gastrin, insulin and serotonin. The immunohistochemical study confirmed multihormonal production. The elevation of growth hormone with acromegaly was also noted in this case. It remains to be seen if the excessive production of growth hormone was due to growth hormone-releasing hormone secreted by the endocrine pancreatic tumor or to the possible presence of a pituitary microadenoma as a component of the multiple endocrine neoplasia type I syndrome.

Adenoma, Islet Cell↗
PubMed1989

[Brainstem auditory evoked potentials in head injury patients].

This study was designed to evaluate the alterations in brainstem auditory evoked potentials (BAEPs) in patients with head injuries. BAEPs were recorded of twenty-five normal subjects to serve as control group. Fifty-four patients with head injuries were evaluate prospectively by neurological check-ups, the Glasgow coma rating scale, brain CT scans, as well as BAEPs. Among them, twenty-two patients accepted a follow-up evaluation one month after the first study. In the acute stage, though the significant prolongation of peak latency occurred only in the right peak III as compared with the control group, the rate of presence decreased significantly in most of the peak waves. There were three main types of abnormality: isoelectric BAEP (13.0%), alterations in peak I (29.6%) and in interpeak latencies (13.0%). The incidence of abnormal BAEPs was 48.2% of 54 patients. Patients were divided into two groups according to whether their coma scale was above/equal to or below 9. No significant difference was shown in the rate of appearance of wave peaks and the average latency of each peak wave. This suggests BAEPs displayed a function of the auditory pathway only rather than a reticular formation in the brainstem. Concerning the group with brain stem abnormality as shown in CT scan, there was significant prolongation in most peak and interpeak latencies, and the rate of presence of each peak was significantly lower compared with the non-brainstem-abnormality group. Therefore, the alteration in BAEPs in head injuries coincide with the presence of abnormal brainstem signs in the CT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Physiological changes of the muscular system in short distance runners].

Fifty high school students of both sexes with an age range of 17 to 19 years were selected for this study. They included 30 males-half regularly did exercise, while half did not and 20 females-half had regularly engaged in sports activities, the other half did not. Before running, on average males had a lower respiratory rate (RR), but a higher blood pressure and serum creatinine kinase (CK) level. In both sexes, students who regularly engaged in sports habits had a lower pulse rate (PR) but higher serum CK. The latter suggested the possibility of sports injury in the males active in sports. After they ran for a distance of 400 meters, there were increased PR, RR, body temperature, skin temperature and systolic pressure; but a decreased diastolic pressure. These physiological signs recovered within the first hour after running, and then were followed by the decrement of blood pressure for two days. The physiological phenomena caused by this kind of anaerobic exercise were more prominent in the groups of students inactive in sports. As for the serum lactate, it rose immediately after running and markedly declined within the first hour. This suggests that short distance running is a typical anaerobic exercise. After their run, serum CK elevated and persisted for two days in the habitual-exercise students, which confirms again the possibility of muscle injury in these students.

Adolescent↗
PubMed1989

[Electrophysiological studies of acute anoxic hypoxia].

This study was designed to analyse the effects of acute anoxic hypoxia on brainstem auditory evoked potentials (BAEPs) and electroencephalogram (EEG) and identify their sensitivities of response. After ether anesthesia, endotracheal intubation was performed on 20 adult Long-Evans rats. Relaxin was injected to immobilize the rats and a rodent respirator was provided for artificial ventilation. Acute anoxic hypoxia was induced by apnea with abrupt cessation of the respirator. The BAEPs and EEG were monitored and analyzed continuously before, during and after hypoxia. Experimental hypoxia was induced initially for 3 minutes and, after recovery, for another 5 minutes. Elapsed time was recorded as the waves altered or became flat. Characteristic wave changes were observed, which included delta bursts, epileptic discharges and alpha coma activity in the EEG; and decreased amplitude or delayed latency in the BAEPs. In all experiments, EEG flattening (71.80 +/- 7.80 sec) significantly preceded the flattening of the BAEPs (146.90 +/- 7.00 sec; Wilcoxon signed rank test, p less than 0.01). However, recovery after reoxygenation was more rapid in the BAEPs than in the EEG (162.80 +/- 18.90, 208.20 +/- 17.90 sec, Wilcoxon signed rank test, p less than 0.05). BAEP loss began with the later waves. In the EEG, during the recovery period epileptogenic foci (45%), delta bursting (45%) or alpha coma activity (40%) appeared. The isoelectric EEG and BAEPs were reversible in 12 of the 18 rats after 3-minutes of apnea and immediately followed by reoxygenation. The results of this study indicate the functional vulnerability of the various structures of the nervous system in regard to hypoxia.

Acute Disease↗
PubMed1989

[Erythrocyte deformability in experimental state and diseased RBC].

By Reid's functional test of erythrocyte deformability, the filtration time of 1 ml 5% erythrocyte suspension through a 5 micron nucleopore membrane was measured from 18 normal people and 19 patients with thalassemia. In the control group, the filtration time at 37.0 degrees C and pH 7.4 was 3.26 +/- 0.38 sec. Erythrocyte deformability was constant while blood temperature stayed between 35.0 degrees C and 42.0 degrees C. However the erythrocyte filtration time prolonged as the blood became alkaline or incubated for more than 2 hours. The filtration time of blood was 4.56 +/- 1.02 sec for thalassemia patients, significantly different (p less than 0.01) as comparing to the normal control group. Poor deformability in diseased blood could be explained by membrane defect. Erythrocyte deformability is a good rheological indicator if the physiological conditions of blood is controlled well.

Erythrocyte Deformability↗
PubMed1988

Treatment of chronic type B hepatitis in Southeast Asia.

In Southeast Asia, 15 to 20 percent of the population are hepatitis B surface antigen carriers. The majority of these carriers have chronic hepatitis and would progress to cirrhosis or hepatocellular carcinoma at an annual incidence of 2 percent and 1 percent, respectively. Previous studies from Southeast Asia suggested that immunosuppressive therapy could be harmful, or at best of no value, and antiviral treatment with vidarabine, picibanil, or even interferon was also unsatisfactory. Currently, a randomized controlled trial of human lymphoblastoid interferon, with or without prednisolone pretreatment, versus placebo in patients with hepatitis B core antigen in the liver and hepatitis B e antigen in the serum is being conducted. Forty-five patients (29 receiving interferon, 16 receiving placebo) have been entered in the trial for at least two months. Actuarial analysis shows that the response to interferon therapy was better than that to placebo. Although flu-like symptoms, hair loss, and body weight loss were seen, no side effect requiring specific treatment has been encountered. These preliminary results suggest that human lymphoblastoid interferon is effective and safe in Oriental patients.

Asia, Southeastern↗
PubMed1988

The prognostic significance of bridging hepatic necrosis in chronic type B hepatitis: a histopathologic study.

A histopathologic follow-up study was conducted in 207 consecutive patients to examine the prognostic significance of bridging hepatic necrosis (BHN) in chronic type B hepatitis. One hundred and eight patients showed BHN and the other 99 intralobular spotty necrosis (SN) on initial biopsy. A higher proportion of patients with BHN healed (45.4% vs 26.4%) or developed cirrhosis (18.3% vs 3%) than the patients with SN. In contrast, intralobular inflammation persisted or recurred more frequently in the SN than in the BHN group (40.4% vs 5.6%). These figures were statistically significant (P less than 0.001). Alternatively, 87% of the patients who developed cirrhosis had had BHN as their initial histologic presentations. The estimated relative risk of cirrhotic progression for the BHN group compared to the SN group was 4:1. We conclude that BHN is a paradoxical prognostic factor, either for healing, or cirrhotic progression.

Biopsy↗
PubMed1988

Acute haemorrhagic leucoencephalitis with a prolonged clinical course.

Two cases of pathologically proven acute haemorrhagic leucoencephalitis with clinical features resembling a cerebral tumour are reported. One patient with a left fronto-parieto-temporal mass showed progressive neurological deterioration leading to death in 3 months. Another patient with a right parieto-temporal mass had mild neurological symptoms for one and a half months before complete recovery except for a seizure disorder, following steroid and decompressive therapy. The cases show that acute haemorrhagic leucoencephalitis may not always be rapidly fatal, but may run a prolonged clinical course with recovery.

Adult↗