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Biomedical subjects

J Wong

Publications and source records attributed to J Wong.

At least 595 records · Page 33Linked to original sources
PubMed1986

Injection sclerotherapy of oesophageal varices with the free-hand technique: experience in Hong Kong.

A prospective study of the efficacy of injection sclerotherapy with the free-hand technique for acute bleeding oesophageal varices was conducted, to evaluate its use in the control of acute variceal bleeding and to assess long-term sclerotherapy as the definitive treatment. Between July 1981 and January 1985, a total of 108 patients (96 men, 12 women with mean age of 54.4 years) had intravariceal injection of 5 per cent ethanolamine oleate. The majority had non-alcoholic cirrhosis and alcoholism accounted for only 18.5 per cent. There were 22 Child's A, 42 Child's B and 44 Child's C patients. During the 411 sessions of injection, major complications occurred in 12 patients (11.1 per cent) with 3 deaths. Of the 145 episodes of acute variceal bleeding 91.7 per cent were successfully controlled. In episodes which required more than one injection to control the bleeding, there was a high mortality of 75 per cent. Over the three and a half year period, 33 out of the 93 patients on long-term sclerotherapy had re-bled (35.5 per cent). Varices were obliterated in 27 patients with a mean of 5.4 injections. From our experience, the procedure is safe and effective. However, its status as a definitive treatment when compared with conventional surgical treatment requires further controlled evaluation.

Adult↗
PubMed1986

Diagnosis and treatment of the inferior vena cava syndrome in advanced malignant disease.

The syndrome of intrahepatic inferior vena cava obstruction has neither been commonly recognized nor adequately described. Symptoms include the abrupt onset of ascites, hepatomegaly, and fluid retention below the diaphragm with edema of the lower extremity. Proteinuria can be associated with these symptoms. When this syndrome has been caused by malignant hepatic enlargement, it has not been well characterized in the literature, and its treatment has been ignored. We have diagnosed the inferior vena cava syndrome due to metastatic liver involvement in 34 patients before death. Thirty-three of these patients were treated using a combination of strip radiotherapy to the hepatic vena cava, with or without hepatic arterial infusion of chemotherapy. Fifty-six percent of the patients completed a full course of radiotherapy, with an 83 percent response rate. A dose of 3,000 to 4,500 rads was found to be safe and provided excellent palliation of ascites and edema. Tumors known to be radiosensitive had the best responses and side effects were few and mild in nature. Recognition and treatment of this condition will assume greater importance as survival is prolonged in more patients with advanced malignancy.

Breast Neoplasms↗
PubMed1986

Chronic gastric ulcers are not predisposed to tumor formation when exposed to a low dose of carcinogen.

The purpose of this experiment was to determine whether chronic gastric ulcers in the rat are predisposed to tumor formation when exposed to a usually noncarcinogenic dose of the carcinogen, N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG). Two groups of rats were prepared; one subjected to a standard ulcer-producing operation, the other as control. Both groups were given oral MNNG (100 mg/liter as drinking water) for 12 weeks, the carcinogen was then stopped and replaced with tap water, and the experiment terminated at 52 weeks. Results showed that a low dose of carcinogen (200 mg) did not induce tumor formation in any of the normal rats. In the presence of a chronic gastric ulcer, only intestinal metaplasia and hyperplastic glandular nodules were observed, but there were no gastric tumors. It is concluded that the presence of a chronic gastric ulcer did not increase the likelihood of gastric tumor formation in rats treated with a noncarcinogenic dose of the carcinogen MNNG.

Animals↗
PubMed1986

Shrinkage of the esophagus after resection for carcinoma.

The purpose of this study was to document and quantitate the degree of shrinkage of resection margins of the esophagus following extirpation for carcinoma. Measurements were made at operation before the esophagus was removed (in-situ), when the removed specimen had been stretched maximally (stretched), with the specimen lying free (contracted), and after fixation (fixed). After resection, there was substantial shrinkage of the margins, and the upper margins underwent a greater degree of shrinkage than the lower margins, with the tumor changing little in length. In the contracted state before fixation, the upper and lower margins were reduced to 44% and 54% of their in-situ lengths, respectively; after fixation, they were 32% and 39%, respectively. Even after maximal stretching, only 73% of the upper and 89% of the lower in-situ resection margins were restored. The overall shrinkage for the whole specimen after fixation was 50%. It is concluded that there is considerable shrinkage of the resection margins in the esophagus from the time of operation to fixation, and this accounts for the discrepancy claimed by surgeons and pathologists regarding the length of the margins. This finding has relevance in the extrapolation of surgical resection margins from pathological specimens.

Carcinoma↗
PubMed1986

Postoperative flexible choledochoscopy for residual primary intrahepatic stones.

Postoperative flexible choledochoscopy was carried out in 103 patients with residual biliary calculi. Forty-one patients had residual stones in the common duct, and 63 patients had residual stones in the intrahepatic ducts with or without stones in the common duct. The majority of the intrahepatic stones were primary stones. Postoperative choledochoscopy was very effective in removing residual common duct stones (95% removed, no morbidity). For intrahepatic stones, removal was more difficult and was associated with a higher morbidity (11.2%). Stone extraction through the stenotic intrahepatic ducts was made possible by the balloon dilatation of the ducts. Repeated endoscopic access to the biliary system was made easier by the construction of a hepatico-cutaneous-jejunostomy, which also provides a route to the biliary tree for future stone removal if stone reformation occurs. Complimented by these procedures, postoperative choledochoscopy was successful in removing the residual intrahepatic stones in 82.3% of the patients. At a median follow-up of 17 months, the majority of the patients who had all the stones removed as well as those who had stones left behind were symptom free.

Adolescent↗
PubMed1986

Tamoxifen versus chemotherapy as adjuvant treatment in stage III breast cancer.

A randomized prospective trial was conducted to compare Tamoxifen and combination chemotherapy (5-fluorouracil, doxorubicin and cyclophosphamide) as adjuvant treatment for patients with locally advanced (Stage III) breast cancer. At the end of 5 years, no significant difference could be found in the disease-free period for both groups.

Actuarial Analysis↗
PubMed1986

A cytosolic binding protein for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the uterus and deciduoma of rats.

The cytosol fraction of the uterus of proestrous rats and of deciduoma specifically binds 3H-2,3,7,8-tetrachlorodibenzo-p-dioxin (3H-TCDD). The 3H-TCDD binding protein has a sedimentation coefficient of 9 S in low ionic 10-40% sucrose density gradients. The binding of 3H-TCDD in the 9 S region is abolished by a 500-fold molar excess of unlabeled benzo[a]pyrene, 3-methylcholanthrene or by a 100-fold molar excess of unlabeled TCDD. Incubation of the binding protein with TCDD in amounts in excess of 500 nM causes aggregation of the TCDD binding protein. Neither estradiol, progesterone, testosterone, dihydrotestosterone nor cortisol competed with TCDD in binding to this 9 S protein. The decidual tissue contains two binding components for TCDD as shown by Scatchard analysis. One of the components has a high affinity for TCDD (Kd = 1.68 nM) and is saturable. The number of binding sites is about 75 fmol/mg protein. The TCDD binding protein eluted through a DEAE-cellulose column using a gradient of 0.25 M KCl. The binding of estradiol and progesterone to their respective receptors was not affected by TCDD or by other polycyclic aromatic hydrocarbons as shown by sucrose density gradients and by microtiter competition assays. These results suggest that TCDD acts by binding to its own receptor system in the target tissue and not by competing with estrogen or progesterone for binding to their receptors. The possible role of the receptor in teratogenesis is discussed.

Animals↗
PubMed1986

A pilot study in adult rhesus monkeys (M. mulatta) treated with Aroclor 1254 for two years.

Aroclor 1254, at a dose level of 280 micrograms/kg body weight equivalent to 200 micrograms/kg/day, was given 5 days per week to rhesus monkeys over a 27 to 28 month period. Terminal clinical signs of varying severity included fingernail detachment, exuberant nail beds, weight loss, stomatitis and normocytic anemia. At necropsy the bone marrow was hypocellular with increased M:E ratio and cytoplasmic vacuoles in erythroid precursor cells. Histopathologic lesions included dilatation of the tarsal gland ducts, atrophy or absence of splenic and lymph node germinal centers, bone marrow depletion, gingival erosion and ulceration, moderate mucinous hypertrophic gastropathy with cystic dilatation of occasional gastric glands, hepatocellular enlargement and necrosis, hypertrophy of biliary duct epithelium, hyperplasia of biliary ducts, hypertrophy of the gall bladder epithelium, and an equivocal increase in the number of lysosomes in thyroid follicular epithelial cells. PCB tissue concentrations were lowest in brain and highest in blood. The results suggest that severe potentially fatal PCB toxicity can develop in rhesus monkeys following ingestion of Aroclor 1254 at 200 micrograms/kg/day for a period of 27 months or longer.

Animals↗
PubMed1986

Biochemical and histologic pathology in an infant with cross-reacting material (negative) pyruvate carboxylase deficiency.

An infant with the acute neonatal form of pyruvate carboxylase deficiency (cross-reacting material negative) presented with severe intractable lactic acidosis within 4 h after birth. He also had hyperammonemia, hypercitrullinemia, and hyperlysinemia. Plasma glutamine was not elevated. He had a rapidly deteriorating clinical course with severe liver dysfunction, repeated septicemia and seizures; he was comatose and was on a ventilator throughout; death occurred at 8 wk of age. Skin fibroblast study confirmed the enzyme deficiency. Detailed biochemical parameters and histopathology of the brain and liver are presented. The evidence from this infant suggests that disturbances of intracellular oxaloacetate levels as a result of the primary enzyme defect might also contribute to deficiency in ATP generation which may explain the various other biochemical changes and liver pathology.

Acidosis↗
PubMed1986

Adrenal phaeochromocytoma and neurofibromatosis presenting with hypotension.

We report a case of adrenal phaeochromocytoma with the stigmata of neurofibromatosis, who presented with acute hypotension. The patient later had episodes of hypertension alternating with hypotension, associated with electrocardiographic changes simulating myocardial infarction, and finally a completed stroke. The circumstances illustrate the problem of early recognition of the protean clinical effects of an excess of circulating adrenal medullary hormones. They also emphasise the need to consider phaeochromocytoma as a differential diagnosis of apparent clinical shock.

Adrenal Gland Neoplasms↗
PubMed1986

N-substituted 11-(4-piperidylene)-5,6-dihydro-11H-benzo-[5,6]cyclohepta [1,2-b]pyridines. Antihistamines with no sedating liability.

Conversion of the basic tertiary amino function of the potent antihistamine, azatadine (Optimine), to neutral carbamate function results in compounds which retain significant antihistamine activity with little or no CNS effects. In guinea pigs the N-ethoxycarbonyl derivative 4 had the same antihistamine potency as terfenadine, a clinically used non-sedating antihistamine. In mice, 4 was a potent antihistamine while lacking CNS effects. The 8-chloro-N-ethoxycarbonyl 5 (loratadine, Sch 29851) was the most potent antihistamine in the series, had no CNS side effects, and was selected for clinical evaluation.

Animals↗
PubMed1986

Lengths of different routes for esophageal replacement.

The lengths of the orthotopic, retrosternal, and subcutaneous routes for esophageal replacement were measured in 20 patients at autopsy. The subcutaneous route is 1.8 cm longer than the retrosternal route, which is 1.9 cm longer than the orthotopic route. The difference between the subcutaneous and the orthotopic route is 3.7 cm.

Adult↗
PubMed1986

Mode of inheritance of Samoyed hereditary glomerulopathy: an animal model for hereditary nephritis in humans.

The pedigree of a line of Samoyed dogs with Samoyed hereditary glomerulopathy (SHG) was investigated to determine the mode of inheritance. Sixty percent of males were affected with severe renal disease that progressed to renal failure before 15 months of age. In contrast, female carriers showed less severe involvement and their disease did not progress to renal failure. This pattern is consistent with the inheritance of an X-linked dominant gene. A similar mode of inheritance has been postulated in some families with hereditary nephritis. Further similarities between SHG in dogs and hereditary nephritis in humans have been demonstrated previously in clinical and renal morphologic studies. The present study supports the view that this line of Samoyed dogs would be an appropriate model for studying the human disease.

Animals↗
PubMed1986

Lateral rhinotomy for intranasal tumors: a review of 22 cases.

Lateral rhinotomy is a surgical approach not employed often enough for evaluation, diagnosis and removal of intranasal neoplasms. This paper reviews 22 patients with intranasal tumors requiring 28 rhinotomies between 1973 and 1984. Our experience indicates that lateral rhinotomy is a safe, repeatable and cosmetically sound procedure that provides and excellent surgical approach to the nasal cavity and sinuses. Determination of the site of origin and adequate surgical removal of intranasal tumors, concomitant surgery to the sinuses and intranasal skin grafting are possible with the procedure.

Carcinoma, Squamous Cell↗