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Biomedical subjects

H R Chen

Publications and source records attributed to H R Chen.

At least 19 recordsLinked to original sources
PubMed1992

[Prevention of pancreatic fistula in pancreaticoduodenectomy: cannulation of the pancreatic duct].

Fifty-two patients with malignant tumours underwent pancreaticoduodenectomy in the past 13 years. A plastic catheter, 3 mm in diameter and 40 cm in length, was used for pancreatic duct drainage and stent, with one end of it inserted into the pancreatic duct and the other end in the jejunal lumen. The cannulation was found to be very effective in stenting the stump pancreatic duct and draining the pancreatic juice away from the anastomotic stoma, hence preventing postoperative leakage. Temporary postoperative fistula occurred in only one patient, and operative death was noted.

Adult↗
PubMed1991

Hydrogen peroxide contrast hepatosonography.

Hydrogen peroxide contrast hepatosonography (HPCH), a new technique, was developed for liver examination. On examination, 5-10 ml of 2-3% hydrogen peroxide was injected into the rectum through a dual-channel rubber tube. When hydrogen peroxide passed through the mucosa into the portal vein, the fast flowing contrast echoes were seen, and the liver parenchyma was covered by enhanced echoes. A total of 297 subjects were examined by HPCH with a successful contrast rate of 95.6%. In normal subjects, dense contrast echoes were visible throughout the liver. But in patients with hepatoma, hemangioma, cyst and abscess, contrast echo defects were noted. We conclude that HPCE is of great value in the differentiation of space-occupying lesions and measurement of portal circulation time and blood flow velocity in spite of its untoward reactions.

Adolescent↗
PubMed1991

Cystic duct occlusion by microwave tissue coagulator in rabbits.

In this preliminary study a flexible bipolar microwave electrode, 1.8 mm in diameter, was designed to occlude the cystic duct in 18 rabbits. Thermal model tests were performed to evaluate the effect of the antenna and to master the coagulating condition. Through surgical cholecystostomy, the antenna was inserted into the proximal cystic duct for various coagulation treatments. Cholecystography showed that the cystic duct was occluded minutes to hours after coagulation. Histologically, the microwave technique induced a chronic inflammation and fibrosis which eventually obliterated the coagulated cystic duct permanently. In group A (30 mA for 20 s) the cystic duct epithelium regeneration occurred and surrounding liver damage was limited, while in groups B (50 mA for 10 s) and C (70 mA for 6 s) no epithelium regeneration was observed and injury to the liver was mild to moderate. It was found that microwaves generated at 50 mA for 10 s to occlude the rabbit's cystic duct are effective and less injurious.

Animals↗
PubMed1990

[Dark epithelial cells in oral premalignant lesions].

Dark basal epithelial cells (D cells) are characterized by a strong affinity for basic dyes and by the high electron density of the cytoplasm and nucleus. These cells have been considered to be putative dedifferentiated precursors of a neoplastic keratinocyte. They are significantly increased in preneoplastic lesions of the human airway and rat trachea induced with chemical carcinogens and/or tumor promoters. Twenty-four cases of oral premalignant lesions were classified as slight, moderate and severe dysplasia, and carcinoma in situ according to the histologic criteria proposed by MacDonald, katz and Pindborg. The percentage of appearance in D-cells of the dysplastic basal layer was calculated and shown as follows: in slight dysplasia 10.6 +/- 0.6%, in moderate dysplasia 22.9 +/- 0.8%, in severe dysplasia 23.9 +/- 0.4%, and in carcinoma in situ 31.4 +/- 0.9%. This result revealed that the increase in the number of D-cells in the basal epithelial layer was in proportion to the severity of the epithelial dysplasia. Thus, the D-cells probably can be used as an indicator in premalignant lesions of the oral cavity.

Epithelium↗
PubMed1989

A newly developed method for treatment of oral lichen planus with ultraviolet irradiation.

In the past, treatment of oral lichen planus (OLP) was usually discontinued by patients due to the many adverse effects such as drug-induced side effects, scarring, etc. In this study, 35 patients with severe OLP which was verified histologically were subjected to irradiation. The lesions were irradiated with ultraviolet (UV) light at wave lengths of 320-400 nm for 5-10 minutes per single exposure once a week. During each irradiation, the patients were protected with eye goggles and no photosensitizer was added. Soreness and discomfort of the oral lesions were markedly relieved after irradiation for 4 treatments. By comparing the pre- and post-treatment findings from clinical, histological and immunohistochemical examinations, 30(85.7%) out of the 35 patients were either cured or improved after 8 treatments of UV-A irradiation. The advantages of UV-A irradiation therapy are as follows: (1) fewer erythemic-induced side effects: (2) marked improvement of lesions within a short period; and (3) no malignant transformation during a period of 5 years following the irradiation.

Female↗