Search PubMed⌕ Search

Biomedical subjects

H K Hsu

Publications and source records attributed to H K Hsu.

At least 37 records · Page 2Linked to original sources
PubMed1998

Enlarging effects of estradiol on the nuclear volume of neurons in the hypothalamus during aging.

Neuronal nuclear volumes (NNVs) were measured in the medial preoptic nucleus (MPN), anterior hypothalamic area (AHA) and arcuate nucleus (ARN) of young adult, middle-aged, and old rats of both sexes. The NNVs in the darkly stained sexual-dimorphic nucleus of the preoptic area (SDN-POA) and the lighter staining surrounding area (non-SDN-POA) within the MPN were measured separately. Intact young and middle-aged female rats had larger NNVs than those of the males in SDN-POA, non-SDN-POA and AHA but not in ARN. During aging, only intact old female rats manifested significant NNV shrinkage in all the measured areas. Long-term treatment with estradiol benzoate (EB) caused a significant enlargement of the NNVs in non-SDN-POA and ARN of middle-aged and old male rats as well as the NNVs in SDN-POA, non-SDN-POA and ARN of old female rats. The enlarging effect of EB on NNVs in both SDN-POA and non-SDN-POA of female rats could be prevented by ovariectomy. Furthermore, NNVs in SDN-POA and non-SDN-POA of ovariectomized female rats were even smaller than those of the age-matched intact female rats. These results indicate that: (1) the NNVs of MPN and ARN in male and female rats were enlarged after long-term exposure of physiological dose of estradiol; (2) the enlarging effects of EB on NNV in MPN can explain why the NNV of intact female rats is larger than that of males, and (3) during aging, the sex-specific shrinkage of NNVs in MPN, AHA and ARN of female rats may be due to an intrinsic aging process rather than long-term effects of EB.

Aging↗
PubMed1997

Differential activation of protein kinase A in various regions of myocardium during sepsis.

Changes in the activities of protein kinase A (PKA) (cAMP-dependent protein kinase) in various regions of rat myocardium during different cardiodynamic phases of sepsis were studied in an attempt to understand the pathophysiology of cardiac dysfunction during sepsis. Sepsis was induced by cecal ligation and puncture (CLP). Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals sacrificed at 9 and 18 hr, respectively, after CLP. Cardiac PKA was extracted and partially purified by acid precipitation, ammonium sulfate fractionation, and DEAE-cellulose chromatography. PKA was eluted from DEAE-cellulose column with a linear NaCl gradient. Two types of PKA, Type I (eluted at low ionic strength) and Type II (eluted at high ionic strength), were collected, and their activities were determined based on the rate of incorporation of [gamma-32P]ATP into histone. Under physiological conditions, Type I PKA activities were unevenly distributed (left atrium > right atrium > pacemaker region > left ventricle > right ventricle > ventricular septum) while Type II PKA activities were evenly distributed among different regions of myocardium. During early sepsis, Type I PKA activities remained unchanged while Type II PKA activities were activated by 32 and 70% in right atrium and pacemaker regions, respectively. During late sepsis, Type I PKA activities were stimulated by 228% in ventricular septum while Type II PKA activities were not affected. These data demonstrate that different PKA activities exist in various regions of the myocardium and that PKA activities were preferentially activated in certain areas during the progression of sepsis. Since PKA plays an important role in the regulation of myocardial function and metabolism, the activation of PKA in different regions of myocardial during different stages of sepsis may contribute to the altered cardiac function during the progression of sepsis.

Animals↗
PubMed1997

Protein kinase a activity is increased in rat heart during late hypodynamic phase of sepsis.

Changes in the activities of protein kinase A (PKA, or cAMP-dependent protein kinase) in rat heart during different cardiodynamic phases of sepsis were investigated. Sepsis was induced by cecal ligation and puncture. Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals killed at 9 and 18 h, respectively, after cecal ligation and puncture. Cardiac PKA was extracted and partially purified by acid precipitation, ammonium sulfate fractionation, and DEAE-cellulose chromatography. PKA was eluted from DEAE-cellulose column with a linear NaCl gradient. Two peaks of PKA, type I (eluted at low ionic strength) and type II (eluted at high ionic strength), were collected and their activities were determined based on the rate of incorporation of [gamma-32P]ATP into histone. Results obtained show that during early sepsis, both type I and type II PKA activities were unaffected. During late sepsis, type I PKA activities were stimulated by 66.7-97.7%, while type II PKA activities remained constant. Kinetic analysis of the data on type I PKA during late sepsis reveals that the Vmax values for ATP, cAMP, and histone were increased by 84.7, 66.7, and 97.7%, respectively; while the Km values for ATP, cAMP, and histone were unaltered. These data indicate that type I PKA is activated in rat heart during late hypodynamic phase of sepsis. Since kinase-mediated phosphorylation plays an important role in regulating myocardial function and metabolism, an activation of type I PKA during late sepsis may contribute to the development of altered myocardial function during hypodynamic phase of sepsis.

Animals↗
PubMed1997

Group II phospholipase A2 gene expression is transcriptionally regulated in rat liver during sepsis.

Changes in group II phospholipase A2 (PLA2) gene expression in rat liver during different phases of sepsis were studied. Sepsis was induced by cecal ligation and puncture (CLP). The results show that PLA2 activity was increased by 41 and 92% during early hyperdynamic phase (9 h after CLP) and late hypodynamic phase (18 h after CLP) of sepsis, respectively. Western blot analysis reveals that group II PLA2 protein levels were elevated by 53 and 95% during early and late sepsis, respectively. Northern blot analysis depicts that the steady-state levels of group II PLA2 mRNA were enhanced by 39 and 114% during early and late sepsis, respectively. Nuclear run-off assay shows that the transcription rates of group II PLA2 gene transcript were stimulated by 36 and 74% during early and late sepsis, respectively. The actinomycin D pulse chase study indicates that the half-life of group II PLA2 mRNA remained unaffected during early and late phases of sepsis. These results demonstrate that group II PLA2 gene transcripts were overexpressed in rat liver during the progression of sepsis and that the overexpression was a result of the enhanced synthesis of group II PLA2 mRNA. Because PLA2 plays an important role in the maintenance of cell membrane integrity, our findings may contribute to the understanding of the pathogenesis of hepatic dysfunction during the progression of sepsis.

Animals↗
PubMed1997

The neonatal neurotoxicity of monosodium L-glutamate on the sexually dimorphic nucleus of the preoptic area in rats.

The neurotoxic effect of monosodium L-glutamate (MSG) on the morphologies in the darkly stained sexually dimorphic nucleus of the preoptic area (SDN-POA) and the lighter-staining surrounding area (non-SDN-POA) within the medial preoptic nucleus (MPN) was evaluated. Male and female Long-Evans rats were used. MSG (4 mg/g of body weight) was administered subcutaneously to pups on days 1 and 3 postnatally. Normal saline was used as the vehicle. At the age of 6 months, the rats were sacrificed and the brain tissues were fixed for histological examination. The morphological changes, i.e., total volume, density, total neuron number, neuronal nuclear volume (NNV) and ratio of pyknosis, of the SDN-POA and non-SDN-POA within the MPN, were estimated using the AMS VIDS III semiautomatic image-analytic system. The results indicate that neonatal MSG treatment caused significant neuronal loss and decreases in total volume of the SDN-POA and non-SDN-POA of male and female rats. However, only the SDN-POA of MSG-treated male rats showed a significant increase of pyknosis and decrease of neuronal density. A significant enlargement of NNV in the SDN-POA and non-SDN-POA was observed in the MSG-treated male rats. These results indicate that the MPN shows sex-specific and area-specific changes after neonatal neurotoxicity due to MSG.

Animals↗
PubMed1997

Reflux esophagitis after proximal subtotal gastrectomy.

BACKGROUND: Carcinoma of the cardia of stomach or carcinoma of the esophagocardiac (EC) junction has a poor prognosis. Proximal subtotal gastrectomy is often performed for a smaller tumor. It achieves a prognosis similar to that of total gastrectomy and prevents pernicious anemia. A better functional result was expected than that total gastrectomy did from us, but the clinical observation was surprising. Most patients had symptoms of reflux esophagitis after surgery. All of these patients were reevaluated. METHODS: From November, 1990 to March, 1996, there were 27 patients who received proximal subtotal gastrectomy at this hospital. Twenty of these were involved in this study. Floppy Nissen's fundoplication was performed during operation as a anti-reflux procedure. Continuous 24-h pH monitoring, esophageal manometry, and endoscopic examination were performed for study. RESULTS: Most of the patients had symptoms of gastroesophageal reflux. 80% (16/20) of the patients were found to have reflux esophagitis under endoscopy. The patients had higher pH scores (mean 85.8 +/- 45.6) than normal (< 17.5), lower pressure of LES (8.03 +/- 7.01 mmHg), shorter total lengths (mean 1.60 +/- 0.56 cm) and intraabdominal lengths (mean 1.29 +/- 0.30 cm) of new lower esophageal sphincters. CONCLUSIONS: Clearly there was failure to prevent reflux esophagitis through floppy Nissen's fundoplication. Severe gastroesophageal reflux did appear after proximal gastric resection. A gastric remnant with safe cut-margin is often too short to perform complete wrapping. Proximal subtotal gastrectomy is not recommended for early cancer of the cardia of the stomach.

Aged↗
PubMed1996

Morgagni hernias: an uncommon cause of chest masses in adults.

Morgagni hernia is a congenital diaphragmatic hernia that occurs secondary to potential anterior medial defects in the diaphragm. Although the hernia usually is diagnosed incidentally, appearing as a mass on chest radiograph, symptoms of bowel obstruction may occur. Surgical repair is required in all cases and may be performed with either the abdominal or transthoracic approach.

Abdominal Pain↗
PubMed1996

Estradiol modulation of neuron loss in the medial division of medial preoptic nucleus in rats during aging.

The age-related morphological changes in the darkly stained sex-dimorphic nucleus (SDN-POA) and the lighter staining surrounding area (non-SDN-POA) within the medial division of preoptic nucleus of Long-Evans rats were studied. The long-term effects of estradiol benzoate (EB) on the changes were also assessed. During aging, the neuron loss in 14-(middle-age) and 22-month-old rats as well as increased pyknotic ratio of neurons in old male rats were observed in SDN-POA, but not in the non-SDN-POA. In female rats, significant neuron loss with advancing age was observed both in SDN-POA and the non-SDN-POA. Neuron loss in SDN-POA of EB-treated males was more severe than that of the intact males, while no significant difference of neuron loss was observed between EB-treated and age-matched intact female rats. However, neuron loss in SDN-POA of ovariectomized female rats was more severe than that of the age-matched intact females. These results indicate that age-related neuron loss in medial preoptic nucleus show sex-specific and area-specific features, and estradiol may play a important role in modulating neuron loss during aging.

Aging↗
PubMed1996

CYFRA 21-1 enzyme-linked immunosorbent assay. Evaluation as a tumor marker in non-small cell lung cancer.

BACKGROUND: The CYFRA 21-1, a newly developed sandwich enzyme-linked immunosorbent assay (ELISA), was used to measure soluble cytokeratin 19 fragment in serum that is expressed in simple epithelium and its malignant counterpart. The present study was designed to investigate whether CYFRA 21-1 is a sensitive and specific tumor marker for non-small cell lung cancer. METHODS: CYFRA 21-1 assay, using two specific monoclonal antibodies (KS 19.1 and BM 19.21) for cytokeratin 19, was measured in 312 serum samples, including 164 lung cancer, 118 benign pulmonary disease, and 30 healthy individuals. The sensitivity of CYFRA 21-1 was also compared with two other markers, carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC), in 164 patients with lung cancer. RESULTS: The median value of healthy individuals was 1.3 ng/mL (95th percentile 1.8). In patients with benign pulmonary diseases, the median was 1.5 ng/mL (95th percentile 2.9). There is no significant difference between sexes, smoking habit, and the subgroups of benign pulmonary disease, such as tuberculosis, pneumonia, or COPD. Using the cutoff value of 3.3 ng/mL, defined at 95% specificity for benign lung disease, the sensitivities of CYFRA 21-1 for squamous cell carcinoma (n=74), adenocarcinoma (n=54), undifferentiated large cell carcinoma (n=11), and small cell lung cancer (n=25) were 62%, 39%, 36%, and 20%, respectively. Despite the cell types, the sensitivities of CYFRA 21-1 in non-small cell lung cancer (NSCLC, n=169) were 51% (CEA 42%, SCC 20%). The sensitivity of CEA was significantly higher in patients with adenocarcinoma (58%) than other markers; while in patients with squamous cell carcinoma, CYFRA 21-1 assay has the highest sensitivity. The median level of CYFRA 21-1 in squamous cell carcinoma is significantly higher than that of other cell types (Mann-Whitney test, p<0.001). The serum level and sensitivity of CYFRA 21-1 were well correlated with staging and tumor size in squamous cell carcinoma. The CYFRA 21-1 values were measured for monitoring progression of disease in 20 patients with squamous cell carcinoma. There is significant difference in paired observation of CYFRA 21-1 level in patients with progressive disease (Wilcoxon signed-rank test, p<0.05), but no difference was observed in patients with stabilized disease (p>0.1). CONCLUSION: For patients with NSCLC, especially in squamous cell carcinoma, CYFRA 21-1 is not only a sensitive and specific tumor marker, but also may be a useful adjunctive marker for disease monitoring.

Adenocarcinoma↗
PubMed1995

Giant bronchoesophageal fistula: a rare complication of bronchial artery embolization.

Bronchoesophageal fistulas after bronchial artery embolization are rare. In the previous literature only 2 cases were recorded. Here we report treatment of a giant bronchoesophageal fistula on both the left and right bronchus. Our surgical treatment included fistula exclusion by esophageal diversion, and esophageal reconstruction was made by retrosternal stomach. The result was good, and the patient made a satisfactory recovery.

Adult↗
PubMed1995

[Effect of pinealectomy on N-methyl-D-aspartate-facilitated receptivity in female rats].

The purpose of this study was to examine the effect of pinealectomy and the possible mechanism of the pineal gland on N-methyl-D-aspartate (NMDA)-associated receptivity in female rats. Monosodium L-glutamate (MSG) was used as a neurotoxin to induce hypogonadal status. Long-Evans rats were divided into four groups: (1) control (C), (2) pinealectomized (Px), (3) MSG-treated (MSG) and (4) pinealectomized MSG-treated (Px-MSG). Two injections of MSG were administered on the first and the third days postnatally with a dose of 4 mg/g body weight. Pinealectomy was performed at six weeks of age. In the first part of the experiment, all four groups of rats were ovariectomized at 3.5 months and implanted subcutaneously with a 2mm silastic capsule filled with 20% estradiol benzoate (EB). One week later, the sexual receptivity was estimated by lordosis quotient (LQ) before and ten minutes after 20 mg/kg B.W. NMDA administration. The result shows that NMDA caused a remarkable increase of LQ in control rats, but no significant effect on MSG-treated rats. There was no significant difference between control and Px rats before NMDA administration, but Px rats exhibited higher LQ than control rats after NMDA treatment. In the second part of the experiment, the effect of pinealectomy on releasability of LHRH neurons was examined indirectly by NMDA-evoked LH secretion. The dosage and sampling schedule were chosen by the dose-response and time course of LH response to NMDA, respectively. Serum samples were collected before and ten minutes after NMDA administration. Serum concentration of LH was measured by radioimmunoassay.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Liver protein kinases in shock: I. Endotoxin administration inactivates protein kinase a in dog liver.

Effects of endotoxin administration on protein kinase A (cAMP-dependent protein kinase) activity in dog liver were investigated. Hepatic protein kinase A was extracted and partially purified by acid precipitation, ammonium sulfate fraction, and DEAE-cellulose chromatography. Protein kinase A was eluted from DEAE-cellulose column with a linear NaCl gradient. Two peaks of protein kinase A, type I (eluted at low ionic strength) and type II (eluted at high ionic strength), were collected, and their activities were determined based on the rate of incorporation of [gamma-32P]ATP into histone. The results obtained 4 h after endotoxin administration (.5 mg/kg, intravenously) show that type I protein kinase A activity was unaffected, while type II protein kinase A activity was inhibited by 26-57%. Kinetic analysis of the data on type II protein kinase A reveals that the Vmax values for ATP, cAMP, and histone were decreased by 31, 39, and 36%, respectively; while the S.5 (substrate concentration required for half-maximal enzyme activity) values for ATP, cAMP, and histone were unaffected following endotoxin administration. These data indicate that endotoxin administration inhibits hepatic type II protein kinase A activity and the nature of inhibition is by a mechanism not competing with ATP, cAMP, and histone reactive sites. Since protein phosphorylation plays an important role in the regulation of cell metabolism and function, our finding may contribute to the understanding of hepatocellular dysfunction during endotoxin shock.

Animals↗
PubMed1994

Changes in the activities of protein kinases A, C, and M in dog heart and liver following endotoxin administration.

Changes in the activities of protein kinase A (cAMP-dependent), protein kinase C (Ca2+/phospholipid-dependent), and protein kinase M (Ca2+/calmodulin-dependent) in dog heart and liver were studied 4 hr following endotoxin injection. Protein kinases A and C were extracted and partially purified by DEAE-cellulose chromatography. Protein kinase M was extracted and partially purified by DEAE-cellulose, DEAE-Sephacel, and calmodulin-Sepharose chromatography. The results indicate that in the heart, both type I (eluted at low ionic strength) and type II (eluted at high ionic strength) protein kinase A activities were unchanged after endotoxin administration. Cardiac cytosolic protein kinase C activity was increased by 50% (p < 0.05) while the membrane-associated protein kinase C activity remained unaltered following endotoxin injection. Cardiac protein kinase M activity was decreased by 38.5% (p < 0.01) post endotoxin. In the liver, type I protein kinase A activity was unaffected while type II protein kinase A activity was decreased by 34% (p < 0.01) following endotoxin injection. Hepatic cytosolic and membrane-associated protein kinase C activities were inhibited by 37% (p < 0.01) and 53% (p < 0.01), respectively, 4 hr postendotoxin. Hepatic protein kinase M activity was decreased by 61% (p < 0.01) after endotoxin administration. These data indicate that the activities of various protein kinases in the heart and liver were modified by endotoxin administration. Since protein kinases regulate cell function through phosphorylation of various substrate proteins, a modification on protein kinase activities may contribute to the development of organ dysfunction in endotoxin shock.

Animals↗
PubMed1994

Use of quantitative CT to predict postoperative lung function in patients with lung cancer.

PURPOSE: To evaluate the effectiveness of quantitative computed tomography (CT) for predicting postoperative lung function in patients with lung cancer. MATERIALS AND METHODS: Preoperative spirometry and conventional CT of the chest were performed in 38 patients. A postprocessing CT program was applied to quantitate the volume of whole-lung parenchyma with attenuations of -500 to -910 HU; this was defined as total functional lung volume (TFLV). The regional functional lung volume (RFLV) of the lobes or lung to be resected was quantitated separately. CT-predicted postoperative forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were derived by multiplying the preoperative spirometry values by (1 - RFLV/TFLV). RESULTS: CT-predicted values correlated well with postoperatively measured results (FEV1: r = .93, P < .001; FVC: r = .86, P < .001) in patients who underwent pneumonectomy or lobectomy, regardless of the patient's preoperative ventilation status. CONCLUSION: This method is effective in the prediction of postoperative FEV1 and FVC in patients undergoing pulmonary resection.

Aged↗
PubMed1994

Management for acute corrosive injury of upper gastrointestinal tract.

BACKGROUND: It is imperative that the surgeon promptly determine the severity of any acute injury of the upper gastrointestinal (UGI) tract by caustic material ingested and the definite therapy be instituted. Prognostic factors of such injuries have not been clearly demonstrated in previous reports. Here, some prognostic factors and recommended emergency surgical indications in clinical assessment are discussed. METHODS: Forty-six patients (22 men and 24 women; age range 19 to 77 years), sustaining acute corrosive injuries to the UGI tract, were retrospectively assessed from November 1990 to May 1993. Immediate management was given to prevent shock, to identify any associated injury and to observe patency of the airway. Emergency operation was performed if any signs of peritonitis, mediastinitis or sepsis were present. Age, sex, time interval between ingestion and initial resuscitation, consciousness, peritoneal sign, shock index, pH value and [HCO3-] in arterial blood gas were evaluated as prognostic factors with respect to mortality. Chi-square test with Yates' correction was used. A p value less than 0.05 was regarded as statistically significant. RESULTS: Suicide attempt by caustic ingestion was in 40 patients (87%) and ingestion was accidental in 6 (13%). Acidic injury was specified in 36 patients (78.3%). In 14 severely injured patients, emergency exploratory laparotomy with or without esophagogastrectomy was performed in 9 (19.6%), of whom 2 survived. The other five patients were treated conservatively, and all died. Overall mortality rate was 26.1% (12/46). A significantly higher mortality rate was observed in patients with age > or = 50 years, positive peritoneal sign, shock index > 1, pH below 7.2 and bicarbonate concentration below 16 mEq/L as revealed by arterial blood gas (p < 0.05). CONCLUSIONS: The prognostic factors related to a higher mortality rate included age 50 years old or more, positive peritoneal sign, shock index above 1, pH below 7.2 and [HCO3-] below 16 mEq/L in arterial blood gas. Recognition of these factors indicates further detailed study will be required to propose a caustic injury score for predicting severity. Nevertheless, emergency operation is recommended if there are positive signs of peritonitis or mediastinitis, shock index above 1, pH below 7.0 and [HCO3-] below 10 mEq/L in arterial blood gas.

Acute Disease↗
PubMed1993

Effects of long-term estradiol exposure on the hypothalamic neuron number.

Neuron density, volume of the area and total neuron number were measured in the medial preoptic area, anterior hypothalamic area and arcuate nucleus of the hypothalamus of young (6-month-old), middle age (14-month-old) and old (22-month-old) male and female rats. Intact male rats did not show neuron loss even in old age, while intact female rats manifested neuron loss in the medial preoptic area, anterior hypothalamic area and arcuate nucleus in old age. Long-term administration of estradiol benzoate to castrated male rats induced neuron loss in the anterior hypothalamic area and arcuate nucleus of the middle age group and in all three areas of the old age group. However, long-term ovariectomy could not prevent neuron loss in these hypothalamic areas in old age. The results suggested that estradiol can have a cumulative impact on the degree of neuron damage and simulate female-type age-related neuron loss in male rats and that there may be the possibility of an intrinsic aging process inducing neuron loss in female rats.

Animals↗
PubMed1993

Electrophysiologic properties of isolated adult cardiomyocytes from septic rats.

In this study, we examined the effect of sepsis on the electrical properties of isolated ventricular myocytes. Sepsis was induced by cecal ligation and puncture (CLP). The control rats were sham-operated. Membrane potentials and ionic currents in isolated cardiac myocytes were measured by the tight-seal, whole-cell patch-clamp technique. The results show that the resting membrane potentials of heart cells were significantly lower in the septic group (18 hr post-CLP) than those in the control group. However, there was no significant difference in action potential duration of 50% and 90% repolarization between the two groups of cells. In voltage-clamp experiments, isoproterenol (10 nM), a beta-adrenergic agonist, caused an increase in L-type calcium current (ICa,L) in a similar magnitude in myocytes isolated from the control and septic rats. Furthermore, isoproterenol failed to modify the time constants for ICa,L inactivation and the overall shape of current-voltage relationship for both groups of cells. These results indicate that formation of a G omega seal and subsequent tight-seal whole-cell recording with patch-clamp technique can be performed in heart cells derived from CLP-induced septic rats, and that septic rat heart is capable of responding effectively to beta-adrenergic stimulation.

Animals↗