Biomedical subjects

H C Peng

Publications and source records attributed to H C Peng.

At least 19 recordsLinked to original sources

PubMed1996

Triflavin, an Arg-Gly-Asp-containing peptide, inhibits the adhesion of tumor cells to matrix proteins via binding to multiple integrin receptors expressed on human hepatoma cells.

Integrins are a superfamily of cell surface glycoproteins that promote cellular adhesion. The interaction of integrins with extracellular matrices such as fibronectin and vitronectin has been shown to be mediated through an arginine-glycine-aspartic acid (RGD) sequence within adhesive proteins. Triflavin, a 7.5-kDa cysteine-rich polypeptide purified from Trimeresurus flavoviridis snake venom, belongs to a family of RGD-containing peptides, termed disintegrins. Disintegrins have been isolated from the venom of various vipers and have been shown to be potent inhibitors of platelet aggregation. In this study, we found that human hepatoma cell adhesion to immobilized matrix proteins (i.e. fibronectin, collagen, laminin, and vitronectin) was differentially affected by various anti-integrin monoclonal antibodies (mAbs) (i.e., alpha3beta1, alpha5beta1, alpha6beta1, and alpha v beta3) as well as by the peptide GRGDS. Indirect flow cytometric analysis of hepatoma cells with anti-integrin mAbs demonstrated that alpha6beta1 was uniformly expressed at a high density, while alpha3beta1, and alpha5beta1 were moderately expressed and alpha v beta3 was expressed in small amounts on hepatoma cells, consistent with the results obtained from immunofluorescence microscopic analysis. When immobilized on plastic wells, triflavin promoted hepatoma cell attachment; this cell attachment was inhibited by either GRGDS or mAbs against integrins alpha3beta1, alpha5beta1 and alpha v beta3). In addition, the binding of FITC-conjugated triflavin to hepatoma cells was inhibited by GRGDS, anti-alpha3beta1, antialpha5beta1, and anti-alpha v beta3 mAbs. Among these mAbs, anti-alpha5beta1 exerted the most pronounced inhibitory effect (>70%) on the binding of triflavin to hepatoma cells. Taken together, these results suggest that triflavin binds via its RGD sequence to multiple integrin receptors (i.e., alpha5beta1, alpha3beta1, and alpha v beta3) expressed on the surface of hepatoma cells, resulting in inhibition of hepatoma cell adhesion to extracellular matrices (i.e., fibronectin and vitronectin).

Antibodies, Monoclonal↗

PubMed1996

Surgical management of the buried penis.

BACKGROUND: Buried penis is a congenital abnormality in which the phallus is concealed within the surface of prepubic skin. It is probably more common than is generally recognized. The objective was to describe the pathophysiology, and search for the best management of this disease. METHODS: Over a period of 6 years, a total of 31 cases receiving surgery for buried penis at this hospital were analyzed. According to their major pathophysiology, patients were divided into three groups: in the first, the major mechanism was poor skin suspension; in the second, prominent suprapubic fat pad was the major cause. In the third group, the dartos fascia was abnormally thickened and attached to the penile shaft. Different surgical techniques were applied in the different groups. RESULTS: All 15 children in the first group had satisfactory results after penile skin fixation. In the second group, nine children underwent adjunctive lipectomy but only five had satisfactory results. Seven patients in the third group needed degloving of the penis and the three cases who underwent preputial unfurling had severe lymphedema of the inner preputial layer. One of them received revision. The end results were good in the other six patients after long-term follow up. CONCLUSIONS: The buried penis occurs in a spectrum. Although, there are three major pathophysiology mechanisms, most of the patients had a combination. Surgical management should be individualized, and results are usually satisfactory. For the obese patient, weight loss is important. Preputial unfurling and using inner preputial layer to cover the defect should be avoided because of severe postoperative lymphedema.

Child↗

PubMed1996

Antenatal diagnosis and early surgery for choledochal cyst: a report of two cases.

Since the advent of routine antenatal sonography to detect fetal abnormalities, two cases of choledochal cyst have been found prenatally in our hospital. The first presented when a choledochal cyst was demonstrated at 31 weeks of gestation, and a firm diagnosis established within 2 days of birth. Technetium 99m disofenin (DISIDA) cholescintigram revealed delayed visualization of the small bowel. The second case was found by ultrasound examination at 21 weeks of gestation to have a choledochal cyst, and diagnosis was confirmed within 3 days of birth. DISIDA scintigram demonstrated complete obstruction of the extrahepatic biliary tree. Both infants received early excision of the cyst at the ages of three and four days respectively. The postoperative course was quite smooth, and there were no abnormal symptoms after follow up of four and two years, respectively. Neonates with distal common bile duct obstruction in association with presumed choledochal cyst should have prompt surgical exploration, and early excision of the cyst is a safe procedure in the newborn.

Adult↗

PubMed1995

Triflavin, an Arg-Gly-Asp-containing peptide, prevents platelet plug formation in in vivo experiments.

Triflavin, an Arg-Gly-Asp-containing peptide from Trimeresurus flavoviridis snake venom (M(r) of 7500 Da) inhibits platelet aggregation through the blockade of fibrinogen binding to activated platelets. The present study demonstrated that the intravenous injection of triflavin (0.1 and 0.25 mg/kg) significantly prolonged the bleeding time about 1.8- to 2.4-fold as compared with control (normal saline) of severed mesenteric arteries in rats, whereas the injection of Gly-Arg-Gly-Asp-Ser (GRGDS) (2-8 mg/kg) failed to increase the bleeding time in this model. Continuous infusion of triflavin (0.08 mg/kg/min) significantly increased the bleeding time about 2.6-fold, and the bleeding time returned to normal within 20 min after the cessation of triflavin infusion. Triflavin (10-20 mg/kg) significantly prolonged the occlusion time of platelet plug formation induced by irradiation of mesenteric venules of fluorescein sodium-pretreated mice. In contrast, trigramin (10-20 mg/kg) and GRGDS (500 and 1000 mg/kg) showed no significant effect. These results suggest that triflavin has an effective antiplatelet effect in vivo and this peptide may be a useful therapeutic agent for arterial thrombosis.

Amino Acid Sequence↗

PubMed1995

Crotavirin, a potent platelet aggregation inhibitor purified from the venom of the snake Crotalus viridis.

A potent platelet aggregation inhibitor in the venom of Crotalus viridis snake was purified to homogeneity by gel filtration chromatography and reverse phase high-performance liquid chromatography. This purified principle, named crotavirin, is a single-chain polypeptide with a mol. wt of 9200 as estimated by SDS-polyacrylamide gel electrophoresis. It inhibited the aggregation of human washed platelets induced by collagen, thrombin and thomboxane analogue (U46619) with a similar IC50 (approximately 1.0 micrograms/ml, 0.11 microM). The binding of fluorescein isothiocyanate-conjugated crotavirin to platelets was abolished in the presence of divalent cation chelator, EDTA, indicating that divalent cation is essential for crotavirin's binding. A monoclonal antibody, 7E3, raised against platelet glycoprotein IIb-IIIa complex blocked the binding of fluorescein isothiocyanate-conjugated crotavirin to platelets, whereas the other monoclonal antibody against glycoprotein IIb-IIIa, 10E5, had no inhibitory effect. In addition, crotavirin inhibited in a concentration-dependent manner the binding of fluorescein isothiocyanate-conjugated rhodostomin, a member of the disintegrin family, to platelets. Its binding to platelets was blocked by disintegrins, e.g. trigramin and rhodostomin. It is concluded that crotavirin is a potent platelet aggregation inhibitor, which acts specifically on an epitope of glycoprotein IIb-IIIa, leading to the blockade of fibrinogen binding to glycoprotein IIb-IIIa and eventually the blockade of platelet aggregation.

Animals↗

PubMed1995

Jejunoileal atresia in neonates.

BACKGROUND: Jejunoileal atresia is the most common intestinal atresia and the most frequent cause of neonatal intestinal obstruction. The prognosis depends on several important factors. The patients reported were collected for evaluation of the factors contributing to their prognoses. METHODS: In the ten-year period from October 1982 to October 1992, all jejunoileal atresia patients who received treatment in this hospital were entered in this study. Possible factors contributing to prognosis, such as prematurity, low birth weight, apple peel atresia, anastomotic leakage, sepsis, short bowel syndrome were evaluated using Mann-Whitney U-test. RESULTS: Twenty-four patients of jejunoileal atresia had been managed in our hospital in 10 years period. Their ages ranged from one to thirteen days old (mean 3.9 days). The numbers and types of atresia were as follow: type I (n = 4), type II (n = 4), type IIIa (n = 10), type IIIb (n = 5), type IV (n = 1). All patients received surgical correction. Nine complications were found in eight patients, which included four anastomotic leakage, three wound infections and two intestinal obstructions. There were three mortalities from sepsis. Total parenteral nutrition was applied to 14 patients (58.3%). The mean hospital stay was 45.1 days, and the survival rate was 87.5%. Low birth weight and anastomotic leakage contributed to prolonged hospital stays (p < 0.05). CONCLUSIONS: Jejunoileal atresia is a common neonatal surgical condition. The prognosis is generally good, except when a patient presented with factors, such as, low birth weight or anastomotic leakage, which prolonged hospital stays. Moreover, sepsis is the only important factor contributing to mortality.

Female↗

PubMed1995

Posterior urethral valves: a report of five cases.

From 1985 to 1993, five male patients with posterior urethral valves were treated at our hospital; they included three newborns, a 32-month-old and a 10-year-old child. On initial examination, all patients showed severe bilateral hydronephrosis and hydroureter on sonographic findings, dilatation of the prostate urethra and trabeculation of the bladder wall in the voiding cystourethrogram; only one patient showed vesicoureteral reflux. Type I urethral valves were present in all patients. Retrograde transurethral ablation of the valves was performed in four patients with good preoperative renal function. The postoperative courses were smooth except for vesicoureteral reflux in one patient and systemic fungus infection in another. Reimplantation of the ureter was done for the vesicoureteral reflux, and the fungus infection was treated by amphotericin B. Cutaneous vesicostomy was performed for a newborn since the urethral orifice was small. He presented with poor renal function and ascites. Delayed antegrade ablation of the valves per vesicostomy and closure of the vesicostomy were done three months later after restoration of the renal function. Renal function returned to normal after operation in all patients, but the function of the upper urinary tract and bladder continence need long-term follow-up.

Child↗

PubMed1994

Characterization of integrin expression and regulation on SW-480 human colon adenocarcinoma cells and the effect of rhodostomin on basal and upregulated tumor cell adhesion.

Integrins are a superfamily of cell surface glycoproteins that mediate cell-extracellular matrix (ECM) and cell-cell adhesion. Immunofluorescence microscopy and flow cytometric analysis using anti-integrin mAbs as the primary binding ligands demonstrated that the platelet integrin receptor alpha IIb beta 3, as well as alpha v beta 3, alpha 5 beta 1 and alpha 6 beta 1, are present on the surface of SW-480 human colon adenocarcinoma cells. Monoclonal antibodies (mAbs) against alpha IIb beta 3 and alpha 5 beta 1 inhibited unstimulated basal adhesion to fibronectin by approximately 30% and 40%, respectively. The surface immunoreactivity of tumor cells for alpha IIb beta 3 was enhanced by pretreatment (5 min) with a phorbol ester (12-O-tetradecanoylphorbol-13-acetate (TPA)) or a lipoxygenase metabolite of arachidonic acid, 12-hydroxyeicosatetraenoic acid (12-HETE) in a dose- and time-dependent manner. SW-480 cells possess a large intracellular pool of alpha IIb beta 3, from which the receptor complex translocates to the cell surface following pretreatment with TPA or 12(S)-HETE. This pretreatment enhances adhesion to fibronectin, which is mediated exclusively by alpha IIb beta 3 integrins. Staurosporine was found to block alpha IIb beta 3 up-regulation and enhanced-adhesion. TPA and 12(S)-HETE also facilitated the redistribution of alpha IIb beta 3 during the enhanced-spreading process. Rhodostomin, an Arg-Gly-Asp- (RGD) containing antiplatelet snake venom peptide, was about 400-times more potent than RGDS at inhibiting control, TPA- or 12(S)-HETE-enhanced adhesion of SW-480 cells to fibronectin. The binding of mAbs against alpha IIb beta 3, alpha v beta 3 and alpha 5 beta 1 was inhibited by pretreatment with rhodostomin, suggesting that rhodostomin binds via its RGD sequence to multiple integrin receptors (i.e., alpha IIb beta 3, alpha v beta 3, alpha 5 beta 1) expressed on the SW-480 cell surface, inhibiting cell adhesion to ECM.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

PubMed1994

Triflavin, an Arg-Gly-Asp-containing peptide, inhibits human cervical carcinoma (HeLa) cell-substratum adhesion through an RGD-dependent mechanism.

Triflavin, a 7.5-kDa cysteine-rich polypeptide purified from Trimeresurus flavoviridis snake venom, belongs to a family of RGD-containing peptides, termed disintegrins, that have been isolated from the venoms of various vipers and shown to be potent inhibitors of platelet aggregation. The interaction of tumor cells with extracellular matrices such as fibronectin, vitronectin, and collagen has been shown to be mediated through a family of cell surface receptors that specifically recognize an arginine-glycine-aspartic acid (RGD) sequence within each adhesive protein. In this study, we show that triflavin dose-dependently inhibited adhesion of human cervical carcinoma (HeLa) cells to extracellular matrices (ECMs; i.e., fibronectin, fibrinogen, and vitronectin). On the other hand, triflavin exerted a limited inhibitory effect on cell adhesion to laminin and collagen (type I and IV). On a molar basis, triflavin is approximately 800 times more potent than Gly-Arg-Gly-Asp-Ser (GRGDS) at inhibiting cell adhesion. When immobilized on plate, triflavin significantly promoted HeLa cell adhesion, and this attachment was inhibited by GRGDS. Furthermore, FITC-conjugated triflavin bound to cells in a saturable manner and its binding was inhibited by GRGDS. In addition, triflavin did not affect [3H]thymidine uptake of HeLa cells during a 3-day incubation. These results suggest that triflavin probably binds to integrin receptors expressed on HeLa cell surface via its RGD sequence within its molecule, thereby inhibiting the adhesion of extracellular matrices to HeLa cells.

Amino Acid Sequence↗

PubMed1994

Intestinal lengthening experience in short-bowel swine.

BACKGROUND: Traditional therapy for short-bowel syndrome is long-term, expensive and inconvenient; it is often associated with high morbidity and mortality. Thus, there has been increasing interest in the surgical management of this syndrome. Intestinal lengthening is attractive not only because of tapering of the dilated intestine, but also for preserving the intestine that is tapered. The purposes of this study were (a) to develop a reproducible surgical technique for intestinal lengthening and (b) to assess the response of the lengthened jejunum to a short-gut situation. METHODS: Fourteen pigs weighing 13-20 kg were chosen for the study. The animals were divided into three groups: Group I: two pigs received a 20 cm jejunum lengthening only; Group II: six pigs received an 80% bowel resection only; Group III: six pigs received an 80% bowel resection, followed by a 20 cm loop lengthening in the residual jejunum four to seven weeks later. All were observed for a period from 4 to 28 weeks. RESULTS: All lengthened loops, of either primary lengthening (Group I) or delayed lengthening (Group III) functioned well and showed no clinical leakage. Three pigs in Group II (bowel resection only) died of malnutrition at the 5th, 10th and 19th postoperative week, respectively. Only one pig in Group III died, 67 days after bowel lengthening, from intestinal obstruction. During sacrificing laparatomy, two pigs in Group III were found to have side to side enteroenteral fistulae between the lengthened loops. The lengthened bowel was found to be normal histologically. CONCLUSIONS: These results proved that intestinal lengthening is technically feasible, and may be useful for patients suffering from surgical short-bowel syndrome and who have not been completely weaned off parenteral feeding.

Animals↗

PubMed1994

Adrenal adenoma with primary aldosteronism in a child: a case report.

Primary aldosteronism caused by an aldosterone-producing adrenal adenoma was documented in an 11-year-old girl who presented with persistent hypertension, headache, tinnitus and hypokalemia. Elevated plasma aldosterone concentration (PAC) (45.5 ng/dl) and suppressed plasma renin activity (PRA) (< 0.3 ng/ml/hrs) were detected. Saline infusion test and postural test helped to confirm the diagnosis. The tumor site was localized by magnetic resonance imaging (MRI). Surgical removal of the tumor yielded dramatic improvement in blood pressure; PAC and PRA returned to normal range. This rare case illustrates the feasibility of recognition and localization of adrenal adenoma in children. The high cure rate by surgical excision warrants careful screening of hypertensive patients with this entity.

Adenoma↗

PubMed1994

Congenital duodenal web in late infancy and childhood: a report of two cases.

Congenital duodenal webs are rare lesions, usually detected during early infancy because of signs of high intestinal obstruction. The occasional patient escapes both symptoms and detection until adolescence or adulthood. This report concerns two cases of congenital duodenal web at different ages and with different clinical manifestations. Case 1, a six-month-old male, was admitted because of abdominal distention and vomiting. Case 2, a 13-year-old boy, was referred here for further evaluation of recurring seizure attacks, elevated blood urea nitrogen and creatinine and hyponatremia. Duodenotomy and excision of the web performed for both patients. Complete amelioration of all symptoms was then observed at Outpatient Clinic follow-up for one year.

Adolescent↗

PubMed1994

Pulmonary sequestration.

BACKGROUND: Pulmonary sequestration is a relatively rare congenital abnormality. It is a cystic mass of nonfunctioning lung tissue which lacks an obvious communication with the tracheobronchial tree and which receives all or most of its arterial blood from anomalous systemic vessels. METHODS: Six patients with intralobar pulmonary sequestration were treated at this Hospital from 1982 to 1993. The two males and four females had ages ranging from 15 years to 56 years. Five of the six patients were symptomatic, with histories of chronic cough, intermittent fever, hemoptysis, and/or pleuric chest pain. The other patient was asymptomatic. Locations of the lesion included the left lower lobe in three, the right lower lobe in two and the right middle lobe in one. RESULTS: All patients received surgical intervention. Lobectomies were performed in five, and segmentectomy in one. There was no postoperative complication or mortality and all have remained asymptomatic during the follow-up period. CONCLUSIONS: A high index of suspicion is the most important element in the diagnosis of pulmonary sequestration. Angiography is mandatory to demonstrate the aberrant arterial supply and the venous drainage of pulmonary sequestration. Surgery should be performed early in order to reduce potentially life threatening obstruction and infection, and hasten the return of normal pulmonary function.

Adolescent↗

PubMed1993

Triflavin, an Arg-Gly-Asp-containing peptide, inhibits tumor cell-induced platelet aggregation.

In this study, we examined the effect of triflavin, an Arg-Gly-Asp (RGD)-containing snake venom peptide, on human cervical carcinoma (HeLa) cell- and B16-F10 mouse melanoma cell-induced platelet aggregation (TCIPA) in heparinized platelet-rich plasma. TCIPA appears to play an important role in the development of certain experimental tumor metastases. Two ADP-scavenging agents, apyrase (10 U/ml) and creatine phosphate (CP) (5 mM)/creatine phosphokinase (CPK) (5 U/ml) completely inhibited B16-F10 TCIPA, but hirudin (5 U/ml) had no effect. In contrast, apyrase and CP/CPK did not inhibit HeLa TCIPA while hirudin completely inhibited it. Furthermore, HeLa cells initially induced platelet aggregation and then blood coagulation at a later stage. In addition, HeLa cells shortened, in a concentration-dependent manner, the recalcification time of normal as well as factor VIII- and IX-deficient human plasma, but did not affect the recalcification time of factor VII-deficient plasma. This suggests that HeLa TCIPA occurs via activation of the extrinsic pathway, probably owing to tumor cell expression of tissue factor-like activity. HeLa cell-induced thrombin generation was confirmed by detection of amidolytic activity towards a chromogenic substrate, S-2238 (H-D-Phe-Pip-Arg-p-NA). Triflavin and GRGDS inhibited, in a dose-dependent manner, TCIPA caused by either cell line. On a molar basis, triflavin was 10,000-30,000 times more potent than GRGDS in this regard. Moreover, monoclonal antibodies raised against glycoprotein (GP) IIb/IIIa complex (i.e., 7E3 and AP2) and against GP Ib (i.e., AP1) completely inhibited HeLa TCIPA. 7E3 and AP2 inhibited B16-F10 TCIPA by up to 80% whereas AP1 showed only 30% inhibition of B16-F10 TCIPA. In conclusion, the inhibitory effect of triflavin on HeLa and B16-F10 TCIPA may be mediated principally by the binding of triflavin to the fibrinogen receptor associated with GP IIb/IIIa complex on the platelet surface. However, GP Ib is also involved in HeLa TCIPA as thrombin formation is the key factor in triggering platelet aggregation caused by HeLa cells.

Animals↗

PubMed1993

Congenital short small intestine: report of three cases.

Three cases are presented in which the recognized syndrome of functional small bowel obstruction with malrotation and short small bowel was diagnosed. Each patient underwent an exploratory laparotomy for intestinal obstruction, which revealed short small intestines with malrotation, measuring 30 cm to 39 cm. Ladd's procedure was performed in each case and gastrointestinal patency was assured during the operations. Two patients received long-term parenteral nutrition and one, in addition, received bowel lengthening using Bianchi's method. However, the symptoms persisted. The third patient received a prokinetic agent (cisapride) but with no effect; the parents withdrew further management. All three patients subsequently died. Although autopsies were performed in two cases, the exact deficits of intestinal motility are unknown.

Female↗

PubMed1993

The multicystic dysplastic kidney in children.

Multicystic dysplastic kidney (MCDK) is the most common renal cystic disease in infancy and the second most common neonatal abdominal mass. It represents an extreme form of renal dysplasia. The key features in MCDK include variability in size, loss of kidney shape, absence of function and obstruction of ureter. Current management is still controversial. The prognosis is largely depended upon the problems of associated anomalies and the condition of the contralateral kidney. From September '82 to September '91, twelve patients with multicystic kidney have been treated at Taichung Veterans General Hospital. Ten of them received elective nephrectomy. The postoperative condition was uneventful. However, there was a high frequency of associated anomalies (41.6%) and pathologic contralateral kidney (50%). Two patients who refused operation were put on close observation and follow-up with ultrasound. During the surgical patients' follow-up period, one suffered from repeated urinary tract infection and the other died of multiple congenital anomalies.

Female↗

PubMed1993

Recurrent pneumonia resulting from retained esophagus following esophageal replacement for corrosive stricture: a case report.

Benign corrosive stricture of the esophagus rarely requires esophageal replacement due to failed dilatation. A patient is presented with severe esophageal stricture from corrosive injury; the native esophagus was eventually replaced with an ileocolon interposition graft. He suffered from recurrent pneumonia one year after operation. Mucocele formation from the retained esophagus with compression of the tracheobronchial tree, was diagnosed by computerized tomographic (CT) scan, and was resected. The clinical status improved dramatically after the procedure. Tracheobronchial compression by mucocele from the retained esophagus should be considered in the differential diagnosis of recurrent pneumonia after esophageal replacement.

Burns, Chemical↗

PubMed1993

[Cantrell's pentalogy: a case report].

Cantrell's pentalogy is a congenital anomaly resulting from embryologic development defect. The anomalies observed in this disorder were: (1) a midline, supraumbilical abdominal wall defect, (2) a defect of the lower sternum, (3) a deficiency of the anterior diaphragm, (4) a defect in the diaphragmatic pericardium, (5) congenital intracardiac defects. Its occurrence in the newborn is quite uncommon, though it was first described by Cantrell and his colleagues in 1958. A one-day-old male fullterm newborn was presented. Omphalocele and partial ectopia cordis were noted immediately after birth. Echocardiogram revealed tetralogy of Fallot with atrium septal defect. Operative findings were sternal cleft, pericardial defect and ventral diaphragmatic defect. The literature on clinical manifestations, embryogenic defect and management of Cantrell's pentalogy is reviewed briefly.

Abdominal Muscles↗