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E K Chan

Publications and source records attributed to E K Chan.

133 records · Page 8Linked to original sources
PubMed1984

Searching for the best weight reduction operation.

At the University of Minnesota under the supervision of one staff surgeon both jejunoileal bypass (JIB) and gastric bypass (GIB) operations have been performed for weight reduction in morbidly obese individuals. During the last 14 years 727 patients underwent end-to-end (40 to 4 cm) JIB and more than 570 patients underwent GIB. This report is based on a comparison of 205 JIBs performed between July 1975 and July 1979, 106 Alden-loop type GIBs (GIB-loop) performed between July 1975 and July 1979, 53 loop GIBs with enteroenterostomies between the limbs of the loop (GIB-EE) performed between May 1980 and May 1981, and 57 Roux-en-Y GIBs (GIB-Roux) performed between May 1981 and May 1982. Adequate weight loss occurred in 80% of the patients who returned for follow-up in all groups. The percentage of excess body weight loss was similar for the first year (65% for JIB, 62% for GIB-loop, 69% for GIB-EE, and 71% for GIB-Roux). The operative mortality and the immediate morbidity rates were uniformly low. The long-term complications for JIB were 37.7% arthralgia, 7.1% oxalate urolithiasis, 5.6% incisional hernia, and 1.4% liver failure. The complications for GIB-loop were 10.2% nausea/vomiting, 1.9% bile reflux gastritis, and 2.8% anastomotic problems; for GIB-EE 23% nausea/vomiting, 7% bile gastritis, 4.6% incisional hernia, and 3.7% anastomotic problems; and for GIB-Roux 16% nausea/vomiting and 1.7% anastomotic problems. The anastomotic problems consisted of afferent loop obstructions and stomal stenosis; there were no leaks. At 1 year plasma cholesterol reduction for JIB averaged 42% (p less than 0.001), GIB-loop 14% (p less than 0.001), GIB-EE 7% (NS), and GIB-Roux 17% (p less than 0.001). One year after operation 49% of 88 JIB patients showed progression of liver disease on sequential biopsy specimens and 20% improvement. In the 78 GIB patients with sequential biopsies, liver disease progressed in 8% and improved in 65%. In summary, comparable therapeutic weight reduction occurred with all the assessed procedures; however, the GIB-Roux was associated with far fewer serious long-term complications. At this time the GIB-Roux procedure is the weight reduction operation we recommend.

Alkaline Phosphatase↗
PubMed1980

Retarding Novikoff tumor growth by altering host rat cholesterol metabolism.

Tumor cells, in vitro, must derive the majority of their required cholesterol from their host milieu. To determine if limiting tumor-available cholesterol results in limited tumor growth in vivo, Holtzman rats were given 10 X 10(6) Novikoff ascites tumor cells subcutaneously. Prior to inoculation, animals received either distal small bowel exclusion or sham operation plus either standard chow or estrone-containing chow (0.0025% or 0.01%) diets. In three separate experiments it was shown that (1) tumor weight was positively correlated with whole plasma cholesterol levels (r = 0.495; P less than 0.05); (2) the lowest tumor weights were correlated with the lowest plasma cholesterol; (3) low density and very low density lipoprotein cholesterol levels were both individually and in combination positively correlated with tumor weight (R2 = 0.828; P less than 0.01); and (4) survival of subcutaneous tumor inoculated animals was significantly greater in those animals shown to have the lowest plasma cholesterol, 27 +/- 1 days versus 29 +/- 1 days; (P less than 0.05). These data support the concept that limiting tumor-available cholesterol by altering host cholesterol metabolism will limit tumor growth.

Animals↗
PubMed1976

Time, dose and volume factors in interstitial Radium implants of carcinoma of the oral tongue.

In a retrospective computer dosimetry analysis of 58 patients with carcinoma of the oral tongue treated with interstitial radium implants alone or in combination with external irradiation, dose and volume appear to be the most important factors in both local control and the incidence of necrosis; in the dose rate range commonly used in clinical interstitial radiotherapy, dose rate has no significant effect. The optimal minimum tumor doses for local control vary with the size of the primary lesion: 6,000 rads for T1 lesions and 6,500 rads for T2 lesions treated with interstitial radium implants alone and 7,500 rads for lesions treated with interstitial radium implants in combination with external irradiation. For lesions treated with implants plus external irradiation, greater local control was achieved when most of the dose was delivered through the interstitial implants. For a given volume, the incidence of necrosis was directly proportional to the degree of overdosage; for a given dose, the incidence of necrosis was directly proportional to the volume receiving the dose.

Carcinoma, Squamous Cell↗
PubMed1976

External and interstitial radiation therapy of carcinoma of the oral tongue. A review of 32 years' experience.

In 204 patients with squamous cell carcinoma of the oral tongue treated with radiation therapy, the most significant prognostic factors appeared to be the presence of neck lymph node metastasis on presentation and the status of the disease three months after treatment. The most common site of failure was the primary lesion, either alone or with neck disease. External irradiation alone was seldom successful. Use of peroral cone irradiation or interstitial implants, either alone or in combination with external irradiation, achieved good local control in early lesions. When the primary tumor was uncontrolled by radiation therapy, salvage with surgery was rare. When failure occurred in the neck alone, radical neck dissection was successful in the majority of cases.

Adolescent↗
PubMedDate not supplied

Association between the nucleolus and the coiled body.

By means of light and electron microscopic immunocytochemistry, we have localized p80-coilin, a specific protein marker for coiled bodies, in mammalian cell lines as well as in primary rat neuron cultures. p80-coilin-stained nuclear bodies, which also contained fibrillarin, could be subsequently silver stained by a method specific for the visualization of nucleolar organizer regions. In cycling cells, most coiled bodies were not associated with nucleoli, whereas in rat neurons such as association was frequent. The treatment of cycling cells with actinomycin D or 5,6-dichloro-1-beta-D-ribo furanosyl-benzimidazole led to nucleolar segregation and/or disintegration, and to an association of p80-coilin staining structures with nucleoli. p80-coilin-positive structures contained fibrillarin in both untreated and treated cells. These results support the opinion that there might be a special association between coiled bodies and nucleoli, particularly in neuronal cells.

Animals↗