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Biomedical subjects

J Wong

Publications and source records attributed to J Wong.

At least 631 records · Page 35Linked to original sources
PubMed1984

An isoelectric variant of the 150,000-dalton neurofilament polypeptide. Evidence that phosphorylation state affects its association with the filament.

A soluble isoelectric variant of the 150,000-dalton neurofilament protein was isolated from bovine brain by treating a partially purified filament preparation with a low-ionic-strength high-pH buffer. The protein (S150) had similar peptide maps to the neurofilament component of the same molecular weight (NF150) and was recognized by a polyclonal antibody made against the NF150 polypeptide. However, only half the anti-NF150 activity could be removed with the S150 protein. In addition, the S150 protein had a higher isoelectric point than the NF150 protein. Phosphate analysis indicated that the S150 protein was considerably lessened in phosphate content, which could account for the higher isoelectric point of the protein. It appears, therefore, that the S150 protein may be a precursor of NF150 or the result of phosphatase activity during the isolation procedure. Assembly studies showed that the S150 protein, unlike the NF150 protein, could not assemble with the 70-kDa neurofilament protein, indicating that the phosphate groups which were removed are important in the association of this protein to the neurofilament. When filaments containing all three triplet neurofilament polypeptides or those composed of the 70- and 150-kDa neurofilament proteins were subjected to acid phosphatase, a soluble fraction was obtained, which contained isoelectric variants with higher pI values than the NF150 polypeptide. Only unmodified NF150 protein was found in the insoluble fraction. These results support the argument that removal of phosphate groups results in the dissociation of this protein from the filament.

Alkaline Phosphatase↗
PubMed1984

Chemotherapy for advanced hepatocellular carcinoma. Adriamycin versus quadruple chemotherapy.

In a prospective clinical trial, 39 patients with advanced hepatocellular carcinoma were randomized to receive either Adriamycin (20 patients) or a combination of 5-fluorouracil, methotrexate, cyclophosphamide, and vincristine (19 patients). Five patients receiving Adriamycin and none receiving quadruple chemotherapy responded (P less than 0.05 in favor of Adriamycin). A further 25 patients were treated with Adriamycin, making a total of 45. The overall objective response rate was 24% (11 patients), with 3 complete remissions and 8 partial remissions. The median survival for Adriamycin-treated patients (13.0 weeks for the first 20 patients and 14.4 weeks for all patients) was longer than those treated by quadruple chemotherapy (6.5 weeks). The difference, however, was not significant by the Wilcoxan test as modified by Gehan. Patients with positive HbsAg had a significantly higher chance of having a response, while serum alpha-fetoprotein levels did not correlate with response.

Adult↗
PubMed1984

Bronchoscopy and carcinoma of the esophagus I. Findings of bronchoscopy in carcinoma of the esophagus.

Tracheobronchial involvement frequently occurs in patients with carcinoma of the esophagus. A study of the results of 525 bronchoscopies performed on patients with carcinoma of the esophagus who were evaluated for surgery revealed that abnormalities were found in 33.9 percent. The incidence was highest for those with cervical and upper-third thoracic tumors; however, a significant number of lower-third thoracic and abdominal tumors also showed abnormalities (12.5 and 5 percent, respectively). The incidence was also higher with large tumors, but again, a significant number of apparently small tumors also showed abnormalities. The abnormalities could be broadly classified into two groups: those showing only impingement and those showing actual invasion. Further studies are needed to determine whether the tumors with impingement are resectable.

Adult↗
PubMed1984

Bronchoscopy and carcinoma of the esophagus II. Carcinoma of the esophagus with tracheobronchial involvement.

Involvement of the tracheobronchial tree, as observed through the bronchoscope, was in the form of impingement or invasion. Bronchoscopy was performed on 525 patients with carcinoma of the esophagus. Impingement was found in 91 patients and invasion in 87 patients. Forty-eight of the 63 patients with impingement and 7 of the 51 patients with invasion were found to have resectable tumors. Bypass operations were performed on the rest of the patients. The operative mortality was high for both bypass and resection procedures. The median survival for bypassed patients and resected patients were 4 months and 9 months, respectively. Four resected patients survived 3 years or more, 2 of whom had no evidence of recurrence. Most patients with impingement have resectable tumors and long-term survival is possible if the tumor can be resected.

Adult↗
PubMed1984

Late problems after pharyngolaryngoesophagectomy and pharyngogastric anastomosis for cancer of the larynx and hypopharynx.

The late problems of 136 patients who had undergone pharyngolaryngoesophagectomy and pharyngogastric anastomosis were studied. The proportions of patients who required long-term thyroxine supplementation were 67 percent, 13 percent, and 5.3 percent of the patients who had total thyroidectomy, hemithyroidectomy, and no thyroidectomy, respectively. The proportions of patients who required calcium and vitamin D supplementation were 67 percent, 23 percent, and 17 percent, respectively. Speech rehabilitation was unsatisfactory. Alimentary functions were satisfactory in that the majority of patients were able to take in solid food. Although a sensation of obstruction of food was occasionally felt, no organic abnormality was found in any patient. Regurgitation was noted in 23 percent of the patients, and hematemesis was an occasional symptom of gastritis or gastric ulcer, although symptomatic gastric ulcer was found in only two patients. It is concluded that the long-term morbidity after this extensive procedure is mild and acceptable. The operation is recommendable for extensive tumors of the laryngopharyngeal region.

Adult↗
PubMed1984

The true pectoralis major myocutaneous island flap: an anatomical study.

The pattern of blood supply to the clavicular and sternocostal portions of the pectoralis major muscle was studied in the cadaver with X-rays of injected specimens. The major blood supply to the sternocostal part was derived from the pectoral branch, although in about 50% of cases the clavicular branch provided minor contributions. This finding supports the clinical experience that it is safe to isolate the full length of the vascular pedicle, deep to the clavicular portion of the muscle, in the preparation of a pectoralis major myocutaneous flap.

Humans↗
PubMed1984

Cholangiography in hepatocellular carcinoma with obstructive jaundice.

Endoscopic retrograde cholangiography or percutaneous transhepatic cholangiography was performed in 22 patients suffering from hepatocellular carcinoma who presented with obstructive jaundice. Cholangiographic features included intraluminal filling defects within the major ducts causing complete or partial obstruction, involvement of the ductal system by tumour encasement resulting in a localised stricture or diffuse irregular strictures and dilatations, and displacement and stretching of the extrahepatic or intrahepatic ducts by tumour mass. Eight patients presented with more than one of these cholangiographic features. The observed cholangiographic features, though not specific for hepatocellular carcinoma, have provided an additional differential diagnosis in interpreting cholangiograms. The information obtained from cholangiography has also enabled selection of patients for surgery and allowed more accurate operative planning.

Adult↗
PubMed1984

Salt taste sensitivity and stimulus volume: sips and drops. Some implications for the Henkin taste test.

Various presentation procedures and stimulus volumes were compared in their effect on salt taste sensitivity. For sodium chloride (NaCl) stimuli pipetted onto the tongue, subjects had comparable measured sensitivity to 10 ml and 1 ml volumes but a reduced sensitivity to 0.1 ml volumes. The greatest sensitivity was achieved with 10 ml sipped volumes. Modification of the Henkin dropwise triangular taste test, by increasing the stimulus volumes, increased subjects' sensitivity. Only the 1 ml pipette presentation increased the sensitivity of the Henkin procedure, albeit slightly, to the detection of changes in taste sensitivity, the purpose for which the procedure was actually designed. Such modification did not perturb salivary NaCl levels more than the regular Henkin procedure, so it would not be expected to introduce sensitivity drift.

Adolescent↗
PubMed1984

The effectiveness of prophylactic subcutaneous mastectomy in Sprague-Dawley rats induced with 7,12-dimethylbenzanthracene.

Fifty-day-old female, albino Sprague-Dawley rats were induced with DMBA, a potent carcinogen that reliably causes multiple breast tumors. Prophylactic subcutaneous mastectomy was performed 2 weeks after injection. Control animals had no breast tissue removed and developed 5.14 tumors per animal, or 1.3 tumors per quadrant. Animals subjected to 50 percent (unilateral) mastectomy developed 5.4 tumors per animal, with 0.72 tumors per surgical quadrant. Animals that underwent 75 percent (three quadrant) mastectomy developed 4.33 tumors per animal, or 0.48 tumors per surgical quadrant. The incidence of tumors was significantly reduced in the surgical areas. However, the risk of any animal developing a breast neoplasm was not reduced in direct proportion to the percentage of breast tissue removed. We believe that this model may prove valuable in evaluating prophylactic subcutaneous mastectomy.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1984

A proposed framework for evaluation of support courses in a nursing curriculum.

Evaluation of nursing educational programmes has received increased attention since the early 1970s. Many evaluation models have been proposed; they are intended for evaluation of the total educational programme, but provide little evidence on the relevancy of the support courses to nursing practice. This paper describes one nursing school's experience in evaluation of a support course. The nature and sources of problems and difficulties encountered during the evaluation process are also discussed. The authors propose a framework for evaluation of support courses in a nursing curriculum. This framework is an application of the Glaser, Stufflebeam and Stake models of programme evaluation. It is designed to assist nurse educators to strive for sound curriculum decisions.

Biochemistry↗
PubMed1984

Promotion of microtubule assembly by neurofilament-associated microtubule-associated proteins.

Intact neurofilaments (NF) purified from mammalian brain and spinal cord promote the assembly of microtubules in solutions of pure phosphocellulose (PC)-purified tubulin. This assembly is temperature-dependent and is inhibited by mitotic spindle inhibitors. The ability of NF to induce microtubule formation is 20% of that of purified microtubule-associated proteins (MAPs), whereas MAPs comprise less than 5% of the protein in the NF preparations. The inducing activity of NF is rapidly lost on boiling. When intact NF are incubated with PC-tubulin and then centrifuged, tubulin is sedimented together with the filaments. This association is inhibited by colchicine and podophyllotoxin and is cold-sensitive. NF purified to homogeneity under denaturing conditions and then reassembled completely lack the ability to promote the assembly of PC-tubulin or to bind tubulin on a centrifugation assay. No MAPs are present in these preparations, though these filaments have the ability to bind exogenous MAPs. While these experiments do not rule out an intrinsic microtubule-assembly-promoting activity, they suggest that this activity is due to nontriplet proteins in the preparation, most likely filament-associated MAPs.

Animals↗
PubMed1984

Intra-caecal short chain fatty acids are altered by dietary pectin in the rat.

When Dark Agouti rats were changed from a conventional pellet diet containing 3.3% crude fibre and 4% fat to the experimental diet containing 5% pectin and 17% fat, the levels of n-butyrate in the caecum rapidly decreased more than fivefold. Such a change could be important as n-butyrate is known to be a major energy source for colonocytes, and to affect colon tumour cell development in vitro. Striking decreases in the caecal concentrations of the short chain fatty acids isobutyrate, n-valerate and isovalerate occurred when Wistar rats were fed an experimental diet containing 5% pectin as the only dietary fibre, compared to rats fed the experimental diet containing no dietary fibre. These large changes in the short chain fatty acid profile, caused by pectin supplementation, have important implications for the metabolism and health of the colon.

Animals↗
PubMed1984

Polychlorinated biphenyl (PCB) toxicity in adult cynomolgus monkeys (M. fascicularis): a pilot study.

Aroclor 1254 and Aroclor 1248, at doses of 11.7 and 4.7 mg/kg body weight (equivalent to 5 and 2 mg/kg/day), were given 3 days per week to groups of cynomolgus monkeys, and caused weight loss, fingernail loss, facial edema, epiphora, and death. Blood and adipose tissue PCB concentrations rose with the length of treatment. Tissue concentrations in blood, adipose tissue, liver and kidneys were highest in monkeys treated with Aroclor 1254, reflecting dose differences. There was considerable variation, both within and between groups, in hematologic responses to PCB treatment. Aroclor 1254-treated monkeys had depressed and weakly responsive erythropoiesis. Aroclor 1248-treated monkeys had active but ineffective or depressed erythropoiesis with severe macrocytic or moderate normocytic anemia. Biochemical determination of blood serum constituents revealed treatment and time-related trends towards hypoalbuminemia and increased alkaline phosphatase, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, lactic dehydrogenase, cholesterol, triglycerides, total bilirubin and direct bilirubin values. Pathologic lesions common in both Aroclor groups were dilatation of meibomian glands duct; mucinous hyperplasia of the gastric mucosa; atrophy and loss of germinal centers in the splenic and other lymphoid follicles; enlargement, fatty degeneration, and necrosis of hepatocytes; bile duct and gall bladder epithelial cell hypertrophy and hyperplasia; and thyroid aberrations in follicular cell size and number of intracytoplasmic lysosomes. Lesions seen exclusively in an Aroclor 1254-treated monkey were widespread mucinous metaplasia and hyperplasia of the fundic mucosa. The results suggest that in general, cynomolgus monkeys may be more refractory or less susceptible to PCB toxicity than rhesus monkeys and, that Aroclor 1248 may be more toxic than Aroclor 1254.

Adipose Tissue↗
PubMed1984

Cholangiographic appearance in clonorchiasis.

Clonorchiasis may lead to cholangitis. Clonorchis sinensis infiltration of the biliary system produces an easily recognisable cholangiographic picture. The findings consist of characteristic filling defects and changes in the intrahepatic and extrahepatic ducts. The filling defects are usually small and irregular and the size is uniform. The change in the intrahepatic ducts consists of ductal dilatation involving especially the smaller ducts, apparent elongation, tortuosity and duct wall irregularities. The changes in the extrahepatic ducts consist mainly of duct wall irregularities and a mild degree of dilatation. The recognition is important as the management may have to be modified if cholangitis is the result of clonorchiasis alone.

Bile Ducts, Intrahepatic↗