Cellular and molecular mechanisms of low dose prolactin potentiation of testicular development in cockerels.

The aim of this study was to determine the cellular and molecular mechanisms of prolactin (PRL) in testicular development of prepubertal cockerels. In an in vivo animal experiment, active immunization against PRL severely depressed prepubertal testicular development by significantly reducing testicular weights at both 122 and 164 d of age. The number of elongated spermatids in the seminiferous tubules was also significantly decreased by immunization with 199-residue chicken PRL (cPRL) at age 122 d. Inhibition of testicular development by cPRL immunization was associated with decreases in LH receptor (LHR), FSH receptor (FSHR), Stat5b, P450scc, steroidogenic acute regulatory (StAR) protein, and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) mRNA expression levels in testicular tissue. In in vitro experiments, testosterone production by cultured Leydig cells isolated from prepubertal cockerel testes was dose-dependently enhanced by treatment with bioactive recombinant PRL, but a lesser response was seen with high concentrations of PRL. The distinct changes in testosterone production in response to high and low concentrations of added PRL were paralleled by similar patterns of change in the mRNA levels of Stat5b, LHR, P450scc, StAR, 3ß-HSD, and CYP17A1 in cultured Leydig cells, as well as protein amounts of phosphorylated Jak2 and Stat5a/b. In conclusion, low to medium doses of PRL potentiate testis development in prepubertal cockerels by enhancing testosterone secretion from Leydig cells via activation of PRLR/Stat5b signal transduction, which upregulates mRNA expression of LHR and testosterone synthesizing enzymes. However, this positive regulation was weaker in response to a high dose of PRL, which reduced PRLR/Stat5b signal transduction and the expression of genes involved in LH signaling and testosterone synthesis.

Eriocalyxin B induces apoptosis of t(8;21) leukemia cells through NF-kappaB and MAPK signaling pathways and triggers degradation of AML1-ETO oncoprotein in a caspase-3-dependent manner.

Diterpenoids isolated from Labiatae family herbs have strong antitumor activities with low toxicity. In this study, Eriocalyxin B (EriB), a diterpenoid extracted from Isodon eriocalyx, was tested on human leukemia/lymphoma cells and murine leukemia models. Acute myeloid leukemia cell line Kasumi-1 was most sensitive to EriB. Significant apoptosis was observed, concomitant with Bcl-2/Bcl-XL downregulation, mitochondrial instability and caspase-3 activation. AML1-ETO oncoprotein was degraded in parallel to caspase-3 activation. EriB-mediated apoptosis was associated with NF-kappaB inactivation by preventing NF-kappaB nuclear translocation and inducing IkappaBalpha cleavage, and disturbance of MAPK pathway by downregulating ERK1/2 phosphorylation and activating AP-1. Without affecting normal hematopoietic progenitor cells proliferation, EriB was effective on primary t(8;21) leukemia blasts and caused AML1-ETO degradation. In murine t(8;21) leukemia models, EriB remarkably prolonged the survival time or decreased the xenograft tumor size. Together, EriB might be a potential treatment for t(8;21) leukemia by targeting AML1-ETO oncoprotein and activating apoptosis pathways.

No decline in preterm birth rate over three decades.

Low socioeconomic status has been associated with risk of preterm delivery. During the past 30 years, Taiwan has had tremendous economic growth and people have attained higher levels of education and living. It is thus not unreasonable to presume that the rate of preterm delivery would decline in response to these changes. The birth registry of Tri-Service General Hospital from 1957 to 1987 was reviewed. The rate of preterm delivery remained stable over the past 30 years, unaffected by these country-wide social changes.

Comparative study of Filshie clip and Pomeroy method for postpartum sterilization.

A prospective randomized comparison of the peri-operative complications and long-term sequelae between the Filshie clip and Pomeroy methods was undertaken in 200 postpartum women at Tri-Service General Hospital, Taipei, Taiwan. The peri-operative complications in either group were mild and infrequent. One pregnancy in the Pomeroy group was reported after follow-up for 24 months. No significant difference between the two groups was found in respect to long-term sequelae.

Neonatal gastric aspirates as a predictor of perinatal hepatitis B virus infections.

OBJECTIVE: To elucidate possible routes and predictors of perinatal transmission of hepatitis B virus (HBV). METHOD: This was a prospective follow-up study. One hundred and forty-seven out of 1762 pregnant women who were screened in the antenatal clinic of a university teaching hospital were HBsAg carriers. Enzyme immunoassay was used for determination of hepatitis B markers. Occurrence of HBsAg in newborns' gastric aspirates, newborns' and infants' blood, and maternal milk samples were determined. Their relationship with delivery routes and duration of the first stage of labor were analyzed by chi square test. RESULTS: The presence of HBsAg in newborns' gastric aspirates was strongly associated with the acquisition of HBsAg by the babies. There was no correlation between the rate of infant antigenemia and the duration of the first stage of labor, nor did cesarean section decrease the rate of vertical transmission of HBV. CONCLUSIONS: This is the first report to provide direct evidence for the major role of the oral route in vertical transmission of HBV during delivery. In addition to maternal serum HBeAg, HBsAg status in newborn's gastric aspirates is another important determinant for vertical transmission of HBV.

[Multicentric carcinoma of the esophagus and double primary malignant neoplasm of the upper alimentary tract--report on 44 patients].

During the past fifteen years, 44 patients with multicentric carcinoma of the esophagus or double primary malignant neoplasm of the upper alimentary tract, collected from 5316 patients with cancer of esophagus or gastric cardia in the same period, were treated in our hospital. The incidence was 0.83%. All were proven by pathology. Exploratory thoracotomy was done in 32 patients and 26 lesions were resected with a resection rate of 81.3%. All patients with cancer resected survived over 1 year, 6 out of 9 survived over 3 years and 2 out of 3, over 5 years. In the 18 patients who received chemotherapy alone, 12 were followed and all died within 1 year. It is shown that multicentric carcinoma of the esophagus or double malignant neoplasm of the upper alimentary tract should be given energetic treatment. Finally, the incidence, diagnosis criteria, diagnosis method, etiology and management are discussed with a review of literature.

[Tissue concentration and secretion of renin in human placental villi during early pregnancy].

In this study, tissue concentrations of renin and angiotensins in human placental villi during early pregnancy and contents of renin and angiotensin I (A I) secreted by cultured chorion were measured by radioimmunal assay (RIA). The results are as follows. During early pregnancy, the human chorion contains renin and A II. The activity of renin is much higher at 6th week of gestation, but as gestation proceeds, it decreases gradually, while A II shows somewhat increased change. The activity of renin secreted by cultured chorion can also be measured. A I in human placental villi can not be detected by RIA in chorion leaves or their culturing fluid. These results indicate that renin-angiotensin system may exist independently in human placental villi during early pregnancy.

[Modulation of the secretion of active renin in human decidual cells by progesterone].

Uterine decidua is a major source of renin, both active and inactive. Active renin cleaves angiotensinogen to produce angiotensin I and exerts its effect on the expression of angiotensin II in the local tissue. Our experiments showed that (1) in the decidua of early pregnancy the contents of active renin increased gradually with advancing pregnancy, and at 8th week of gestation the level of active renin reached to a maximum (63.37 +/- 12.84) AI ng/gww.h(-1); (2) active renin accounted for about 1/4 of the total renin; and (3) the synthesis and secretion of active renin were regulated by progesterone in incubated decidual cells. These data indicate that a high level of active renin in decidual tissue at early pregnancy plays an important role in the uterine renin-angiotensin system during pregnancy.

[Clinical application and technical problems of colonic interposition for esophageal substitution].

From Jan. 1980 to Jan. 1991, A total 41 patients, including 22 patients with corrosive stricture after esophageal chemical burns, 10 patients with cancer of the laryngopharynx, 7 patients with esophageal cancer and 1 case of cardiac carcinoma, underwent of colonic interposition for esophageal substitution. This accounted 0.7% of all of the esophageal reconstruction during the same period. There were 23 cases of retrosternal colonic bypass and 18 cases of trans-hiatal inversion-stripping esophagectomy without thoracotomy. The main postoperative complications were anastomotic leakage at the cervical region and incision infection, but no mortality. The indications, choice of the colonic segment and the technical problems of this operation were discussed.