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Biomedical subjects

J Z Yang

Publications and source records attributed to J Z Yang.

6 recordsLinked to original sources
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↗
PubMed1989

[Diagnosis and treatment of insulinomas--analysis of 6 cases].

Six patients with insulinoma treated from 1977-1986 are analysed. All patients had symptoms of neuro-glucopenia, hypoglycemic coma and sympathetic irritation. The fasting blood glucose level was below 30 mg%. The fasting plasma IRI was 17.3-19.84 mu u/ml and the IRI/glucose ratio was greater than 0.3 in four patients. The symptoms disappeared after the tumor was removed in three patients. One patient was complicated by pancreatic fistula after tumor resection, but was cured by drainage. One patient who had multi-insulinomas undiagnosed preoperatively had Whipple's triad after operation. One was treated by other methods because of his cardiovascular disorders. The percutaneous transhepatic portal catheterization segment IRI assay is a reliable method, especially when combined with abdominal selective arteriography, for the pre-operative diagnosis of insulinoma. The IRI/glucose ratio is more reliable than either glucose or IRI alone.

Adenoma, Islet Cell↗
PubMed1987

[Hyperfunctioning parathyroid carcinoma].

Two cases of parathyroid carcinoma with hyperparathyroidism, a relatively rare endocrine tumor are reported. It accounts for approximately 1-4% of all cases of primary hyperparathyroidism. Parathyroid crisis occurred for three times in one case. It is difficult to make an early diagnosis, frequently leading to misdiagnosis and wrong treatment. During operation iatrogenic implant or incomplete resection may occur, resulting in recurrence and repeated operations. It is important to differentiate from hypercalcemia caused by parathyroid adenoma. Neck mass, hypercalcemia usually above 14 mg%, severe decalcification and pathological fractures are characteristic. Fibrosis and inflammatory reaction of the tumor and metastases in the neck lymph nodes are commonly seen at operation. Histologically active tumor cell mitosis, capsular and vascular invasions usually exist. Local recurrences often occur after surgical treatment. If the surgeon can recognized the malignant change and give a curative resection in the initial operation, more gratifying results can be obtained.

Adult↗
PubMed1983

Radiographic diagnosis of meconium peritonitis. A report of 200 cases including six fetal cases.

The radiographic findings of 200 cases of meconium peritonitis were analyzed; 194 cases were discovered in newborn infants and six cases in fetuses. The radiographic features in the newborn group could be categorized as pneumoperitoneum with intestinal obstruction (adhesions) and calcification (35 cases), intestinal obstruction with calcification (143 cases), intestinal obstruction with no radiographically visible calcification (5 cases), and calcification alone (11 cases). All six cases of the fetal group were diagnosed when the mothers had been hospitalized for polyhydramnios and a plaque-like or ring-like calcification showed up in the fetal abdomen on the plain radiograph. Meconium peritonitis is one of the few conditions that can be diagnosed before birth and is almost the only condition around the time of birth to produce calcification in the abdomen. Therefore, if there is any sign of polyhydramnios, radiographs or ultrasonograms of the maternal abdomen should be obtained to detect any calcification within the peritoneal cavity of the fetus. A simple experiment carried out in rats showed that it takes at least eight days after the meconium escapes into the peritoneal cavity for calcification in the meconium to be radiographically demonstrable.

Adult↗