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Biomedical subjects

F C Chen

Publications and source records attributed to F C Chen.

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

Role of capsaicin sensitive nerves in epidermal growth factor effects on gastric mucosal injury and blood flow.

BACKGROUND: Epidermal growth factor (EGF) and capsaicin protect against experimental gastric mucosal injury. Capsaicin exerts its gastroprotective effect by stimulating afferent neurones leading to release of calcitonin gene related peptide (CGRP) which causes gastric hyperaemia. EGF also causes gastric hyperaemia but whether it acts via capsaicin sensitive neurones is unknown. AIMS: To assess the influence of: (1) capsaicin desensitisation on EGF effects on gastric mucosal injury and gastric mucosal blood flow: and (2) close arterial infusion of hCGRP8-379, a CGRP antagonist, on EGF effects on gastric mucosal blood flow. METHODS: The absolute ethanol induced gastric mucosal injury model in the rat was used. Gastric mucosal damage was assessed by planimetry and light microscopy. Gastric mucosal blood flow was measured by laser Doppler flowmetry in a gastric chamber preparation. RESULTS: Capsaicin desensitisation abolished the gastroprotective and gastric hyperaemic effects of EGF. Close arterial infusion of hCGRP8-37 antagonised the hyperaemic effect of both capsaicin and EGF. CONCLUSION: Results show that EGF may exert its gastroprotective and gastric hyperaemic effects via capsaicin sensitive afferent neurones.

Animals↗
PubMed1998

Ductal dilatation and stenting for residual hepatolithiasis: a promising treatment strategy.

BACKGROUND AND AIMS: Hepatolithiasis is prevalent in south-east Asia and presents a difficult management problem. Intrahepatic strictures with or without awkward ductal angulation of the biliary tree are the main reasons for the reported high incidence of postoperative residual stones. Without proper treatment, biliary strictures and residual stones can lead to repeated episodes of cholangitis, liver abscess, secondary biliary cirrhosis, portal hypertension, and death from sepsis or hepatic failure. The purposes of our treatment strategy were to achieve complete clearance of the stones and relief of bile stasis. METHODS: From January 1991 to July 1992, 90 patients with residual postoperative hepatolithiasis and intrahepatic strictures were treated. Postoperative ductal dilatation with percutaneous transhepatic cholangioscopy tube stenting through a mature T tube tract was performed. Choledochoscopic electrohydraulic lithotripsy was applied when impacted or large stones were encountered. RESULTS: Complete clearance of stones was achieved in 78 patients (87%). Mild haemobilia occurred in five patients (5.5%) and fever developed in seven patients (7.7%), and these patients recovered after conservative treatment. The rate of stone recurrence after a mean follow up of 43 months was 8%. Intrahepatic cholangiocarcinoma developed in one patient (1.1%). CONCLUSION: Postoperative ductal dilatation and stenting, combined with endoscopic electrohydraulic lithotripsy when indicated, is an effective and safe treatment with a low recurrence rate for complicated residual hepatolithiasis with biliary stricture.

Adult↗
PubMed1997

In vitro anti-HIV activity of biflavonoids isolated from Rhus succedanea and Garcinia multiflora.

Eleven biflavonoids, including amentoflavone (1), agathisflavone (2), robustaflavone (3), hinokiflavone (4), volkensiflavone (5), morelloflavone (7), rhusflavanone (9), succedaneaflavanone (10), GB-1a (11), GB-1a 7"-O-beta-glucoside (13), and GB-2a (14) isolated from Rhus succedanea and Garcinia multiflora, as well as their methyl ethers, volkensiflavone hexamethyl ether (6), morelloflavone heptamethyl ether (8), and GB-1a hexamethyl ether (12), were evaluated for their anti-HIV-1 RT activity. The results indicated that compounds 3 and 4 demonstrated similar activity against HIV-1 reverse transcriptase (RT), with IC50 values of 65 microM. Compounds 1, 2, 7, 11, and 14 were moderately active against HIV-1 RT, with IC50 values of 119 microM, 100 microM, 116 microM, 236 microM, and 170 microM, respectively. Morelloflavone (7) also demonstrated significant antiviral activity against HIV-1 (strain LAV-1) in phytohemagglutinin-stimulated primary human peripheral blood mononuclear cells at an EC50 value of 6.9 microM and a selectivity index value of approximately 10. The other biflavonoids were either weakly active, inactive, or not selective against HIV-1 in human lymphocytes.

Anti-HIV Agents↗
PubMed1997

Reconstruction of a large thoracoabdominal wall defect with a flow-through forearm flap and a latissimus dorsi-groin flap.

We report a case of a 45-year-old man with a recurrent, large, invasive dermatofibrosarcoma protuberans over the left lower chest and abdomen. Wide surgical excision of the tumor created a major thoracoabdominal wall defect. Wound coverage was achieved by using a flow-through forearm flap and an inferiorly based latissimus dorsi-groin flap. Follow-up at 1 year revealed no local recurrence or herniation.

Abdominal Muscles↗
PubMed1996

Results of colectomy for severe slow transit constipation.

PURPOSE: This study assesses the outcome of a standardized operation performed by two surgeons for severe idiopathic slow transit constipation that was resistant to laxative treatment. METHODS: Fifty-nine consecutive patients, 4 men and 55 women, with a mean age of 42.3 years, underwent colectomy with ileorectal anastomosis. Slow colonic transit was demonstrated in each case. Fifty-two patients were available for follow-up, with median time to follow-up being 42 (range, 3-81) months. RESULTS: Median bowel frequency was 4 per 24 hours. Sixty-nine percent had four or less bowel movements daily. Ten percent used antidiarrheal medication regularly. One patient had a stoma for recurrent severe constipation. Mean continence score was 1.8 (on a scale of 0-20); six patients were incontinent, and four of these six had normal preoperative anal manometry. Fourteen patients (27 percent) had difficulty with rectal evacuation. Preoperative defecating proctography was a poor predictor of postoperative evacuation difficulties. Twenty-seven patients (52 percent) had persisting abdominal pain, but there was a significant improvement in the degree of pain (P <0.00001). Forty-seven patients (90 percent) were satisfied with the outcome of the operation (and would elect to have it done again). Dissatisfied patients had recurrent constipation or diarrhea and incontinence. CONCLUSION: Colectomy with ileorectal anastomosis produces a satisfactory functional outcome in the majority of patients undergoing surgery for severe constipation with proven slow colonic transit.

Adolescent↗
PubMed1996

The effects of sample size and variability on the correlation coefficient.

The purpose of the study was to investigate the effects of variability as a function of sample size on the Pearson product-moment correlation coefficient (PCC) under the assumption of a perfect relationship between two variables. The effects of sample size (subjects/trials) and variability on the PCC were demonstrated using a computer model. The model was also used to evaluate selected examples taken from the literature. The results indicated that variability in excess of 10% of the range for each variable resulted in a mean reduction of the shared variance by 50% or greater. Although sample size did not affect the mean PCC, it did have a dramatic effect on extreme percentile values producing unreliable results. These results indicate that a small PCC value can be an artifact of variability. It is suggested, therefore, that one should be cautious when stating conclusions regarding the relationship between two variables without having knowledge of the associated variabilities.

Humans↗
PubMed1996

Ileostomy dysfunction with adjuvant chemoradiation for rectal carcinoma requiring in-hospital management: a cause for concern.

The morbidity and mortality of 20 patients undergoing adjuvant chemoradiation for rectal carcinoma was documented. Of nine patients with defunctioning loop ileostomies, two suffered from dehydration and electrolyte disturbance during the treatment phase and required admission to hospital. These two cases suggest that dehydration and electrolyte disturbance from high stomal output could be a serious problem following chemoradiation therapy in patients with an ileostomy.

Antimetabolites, Antineoplastic↗
PubMed1996

Nature of the lip reed.

Reed instruments have been categorized into two families since Helmholtz: the "striking inward" and the "striking outward" reeds. In an attempt to clarify the question to which family the lips of the brass player belong, a Helmholtz resonator with active feedback was used as a single-mode brass instrument and the playing frequencies generated by three trumpet players were measured. By adjusting the gain and the phase in the feedback loop, the resonant frequency and the quality factor of the resonator can be varied. The acoustic impedance at the mouthpiece is measured by a novel method without removing the play's lips. The results show that with extreme efforts the players can generated playing frequencies both lower and higher than the corresponding air column resonance, but that the playing frequency under normal playing conditions (the "most comfortable note") is almost always higher than the corresponding air column resonance. This supports the view that human lips function as "striking outward" reeds.

Acoustics↗
PubMed1996

Effect of capsaicin and cimetidine on the healing of acetic acid induced gastric ulceration in the rat.

BACKGROUND: Capsaicin protects the gastric mucosa against experimental injury while capsaicin desensitisation reduces the rate of gastric ulcer healing. The effect of exogenous capsaicin on gastric ulcer healing has not to date been reported. AIM/METHOD: To investigate the effect of capsaicin, cimetidine, and in combination, given intragastrically in the healing of acetic acid induced chronic gastric ulcer in the rat. Treatment started immediately after ulcer induction. RESULTS: At the end of one week, capsaicin, cimetidine, and in combination increased ulcer healing but the effect of combined treatment was less than that of capsaicin alone. In an in vivo gastric chamber preparation, capsaicin increased, while cimetidine decreased, gastric mucosal blood flow measured by laser Doppler flowmetry. A dose response effect in reduction of gastric mucosal blood flow could be demonstrated for cimetidine. The gastric hyperaemic effect of capsaicin was blunted by prior administration of cimetidine. In contrast, capsaicin had no effect on gastric acid secretion and its addition to cimetidine did not affect the acid suppressant effect of the latter. CONCLUSIONS: Capsaicin promotes the healing of acetic acid induced gastric ulcer, probably by its gastric hyperaemic effect. Although cimetidine also promotes ulcer healing due to its inhibitory effect on acid secretion it may have an antagonistic effect on the gastric ulcer healing effect of capsaicin by virtue of inhibition of gastric hyperaemia.

Acetic Acid↗
PubMed1996

[Removal of femoral interlocking nail-induced pulmonary embolism under spinal anesthesia--a case report].

Most of the lower limb surgeries are done under spinal anesthesia. This 21 year-old male had undergone open reduction with interlocking nail for his right femoral fracture and was scheduled for removal of interlocking nail. Spinal anesthesia was performed and a sensory block up to T8 level was achieved. During removing of the nail, the patient complained of chest pain, dyspnea and headache. Consequently, tachycardia and hypotension were observed. Then he coughed up pink frothy sputum. Ephedrine 5 mg was given to raise his blood pressure. About 3 min later, he recovered from the hypotension. Arterial blood gas analysis showed hypoxemia and hypercapnia. After endotracheal intubation, he was sent to surgical intensive care unit. In surgical intensive care unit, fat globules in urine, anemia and thrombocytopenia were noted. Chest roentgenogram showed patchy pulmonary infiltrates in the left lower lobe. A pulmonary artery catheter was inserted for pulmonary measurement, which read pulmonary artery pressure 45/28 mmHg, wedge pressure 14 mmHg, and cardiac output was 5-34 L/min. Supportive treatment which included steroid therapy, and O2 therapy with positive end-expiratory pressure was initiated under the impression of pulmonary embolism. The course in surgical ICU was uneventful and he left there three days later and was discharged on the fifth hospitalization day.

Adult↗
PubMed1995

Early experience with postoperative adjuvant chemoradiation for rectal carcinoma: focus on morbidity.

The morbidity of postoperative adjuvant chemoradiation for primary extraperitoneal rectal carcinoma is documented in this ongoing study. Patients who presented electively for resection with ACPS Dukes' B and C extraperitoneal rectal carcinoma during the period January 1990 to June 1993 were studied. Twenty patients received postoperative adjuvant chemoradiation. At a mean follow up of 32.6 months (s.d. 7.1), three of the 20 patients who received combined adjuvant chemoradiation reported no side effects. In 10 patients (50%) complications were classified as minor. In the remaining seven patients (35%) major complications of therapy occurred. There were no deaths. These early results highlight the morbidity of postoperative adjuvant chemoradiation that has been presumed but not documented.

Adult↗
PubMed1995

Meigs' syndrome in association with a locally invasive adenocarcinoma of the fallopian tube.

A patient with recurrent pleural effusions posed a diagnostic challenge. The pleural aspirate CA-125 assay was markedly elevated which indicated a primary ovarian pathologic process. However, in this case a rare fallopian tube adenocarcinoma was the underlying problem. Meigs' syndrome can resemble a metastatic pelvic carcinoma in its presentation, but the prognosis is much more favourable when the syndrome is associated with a benign ovarian tumour.

Adenocarcinoma↗
PubMed1995

Effect of capsaicin and chilli on ethanol induced gastric mucosal injury in the rat.

Capsaicin, the pungent ingredient of chilli, is gastroprotective against experimental gastric injury when given intragastrically. Epidemiological and clinical data suggest that chilli ingestion may have a beneficial effect on human peptic ulcer disease. This study showed a gastroprotective effect of intragastric capsaicin, in doses of 2 and 5 mg, on ethanol induced gastric mucosal injury using macroscopic, histological, scanning electron microscopic, and biochemical indices. Subcutaneous administration of 2 mg of capsaicin had the same gastroprotective effect as intragastric administration. Acute intragastric administration and chronic ingestion of chilli powder in doses comparable with that consumed in humans (up to 200 mg in single doses or 200 mg daily for four weeks) likewise protected the gastric mucosa. Both the mucosa and gastric juice had higher mucus contents when capsaicin or chilli rather than saline or solvent was used before ethanol challenge. In control animals capsaicin also increased gastric juice mucus content although the mucosal content was unaffected. Increased gastric mucus production may therefore be one mechanism by which capsaicin and chilli exert their gastroprotective effect although an alternative explanation is that the reduction in mucosal mucus depletion is secondary to the protective effect of capsaicin and chilli.

Administration, Topical↗
PubMed1994

Vascular patterns of gestational trophoblastic tumors by color Doppler ultrasound.

BACKGROUND: Destruction of uterine vasculature is a common phenomenon in gestational trophoblastic tumors. The authors categorized such uterine vasculature by color Doppler ultrasound and studied its clinical significance. METHODS: Color Doppler ultrasound was performed in 28 patients with gestational trophoblastic tumors. The vascular morphologic manifestations were recorded, and the peak systolic velocity and resistance index of uterine artery were calculated. Serum beta-human chorionic gonadotropin (hCG) levels were measured periodically to monitor chemotherapy response. Seventeen uneventful postmole uteri were used as controls. Two-tailed Student's t-test and Fisher's exact test were used for statistical analysis. RESULTS: The gestational trophoblastic tumors were categorized as diffuse type (N = 7), lacunar type (N = 16), and compact type (n = 5) according to their vascular patterns. The mean serum beta-hCG level at diagnosis in diffuse type lesions (6608 +/- 6320 mIU/mL) was significantly lower than in the lacunar type (40462 +/- 39735 mIU/mL; P = 0.04) and compact type (212114 +/- 205126 mIU/mL; P = 0.02), whereas the level in compact type lesions was significantly higher than in the lacunar type (P = 0.003). Lacunar type lesions exhibited a significantly lower uterine artery resistance index (0.51 +/- 0.13) than diffuse type (0.66 +/- 0.10; P = 0.03) or compact type lesions (0.70 +/- 0.06; P = 0.02). All lesions exhibited significantly higher peak systolic velocity than control subjects (P < 0.001); however, no significant difference was observed among them. Brief courses (< 5 cycles) of chemotherapy cured more diffuse type (6 of 7) than lacunar type (3 of 15, P = 0.006) or compact type lesions (0 of 5, P = 0.008). Histopathologic diagnosis was available for 11 lesions. They were invasive mole in seven lacunar type lesions and choriocarcinoma in four compact type lesions. CONCLUSION: Vascular morphologic patterns of gestational trophoblastic tumors by color Doppler ultrasound correlated well with beta-hCG levels, uterine hemodynamics, chemotherapy response, and possibly the histopathologic diagnosis.

Arteries↗
PubMed1994

N-methyl-2-pyrrolidone as a cosolvent: relationship of cosolvent effect with solute polarity and the presence of proton-donating groups on model drug compounds.

N-Methyl-2-pyrrolidone (methylpyrrolidone), a cosolvent which has been used in veterinary medicine and in transdermal delivery devices, was investigated as a cosolvent for model drug compounds of widely varying polarity. These compounds were digoxin, sulfamethoxazole, hydrocortisone acetate, theophylline, phenytoin, and reserpine. Methylpyrrolidone was found to be an extremely efficient cosolvent for low solubility polar drugs such as digoxin or drugs containing multiple proton-donating groups such as phenytoin. The increase in solubility observed in aqueous solutions of digoxin and phenytoin to which 0.2 volume fraction of methylpyrrolidone was added was 500x and 65x, respectively. Significant deviations from log-linear solubilization were observed with digoxin, sulfamethoxazole, phenytoin, and reserpine, indicating significant water-solute-cosolvent interactions.

Chemical Phenomena↗