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Biomedical subjects

P Chan

Publications and source records attributed to P Chan.

At least 217 records · Page 12Linked to original sources
PubMed1989

Evaluation of the Pipelle curette for endometrial biopsy.

The Pipelle endometrial suction curette was evaluated, and its application and effectiveness were compared to those of the Novak curette for endometrial sampling during the midluteal phase. Fifty women underwent an endometrial biopsy with the Pipelle and Novak curettes. Ninety percent of the women preferred the biopsy with the Pipelle. Histologically, tissue obtained with the Pipelle was satisfactory and similar to that with the Novak. The Pipelle curette appears to be an excellent device for midluteal endometrial biopsy during an infertility evaluation.

Biopsy↗
PubMed1988

Continuous arteriovenous hemodialysis: an alternative therapy for acute renal failure associated with critical illness.

Critically ill patients often cannot tolerate conventional hemodialysis because of hemodynamic instability. Continuous arteriovenous hemofiltration provides control of fluid and electrolyte balance but is inefficient in the management of azotemia. Continuous arteriovenous hemodialysis (CAVHD) combines dialysis with hemofiltration. We performed 15 CAVHD treatments of 2 or more days' duration in 12 critically ill patients aged 23 to 85 (mean 64.4) years who had acute oliguric renal failure as a component of multiple organ system failure and who were unsuitable for conventional hemodialysis. The total treatment time was 106 days. The serum creatinine and urea levels were controlled in all the patients during CAVHD. The ultrafiltrate losses were sufficient to allow appropriate nutrition and fluid administration and still maintain a negative fluid balance. Renal function returned in five patients (42%), of whom four survived to be discharged home. CAVHD is an effective means of managing acute oliguric renal failure in critically ill patients.

Acute Kidney Injury↗
PubMed1987

Accelerated healing of carbon dioxide laser burns in rats treated with composite polyurethane dressings.

Healing time, infection rate, and residual scar formation were compared in carbon dioxide laser burns in rats treated in four ways: Spandra composite dressing, OpSite composite dressing, Petrolatum Gauze (USP), and no treatment. There were no infections and no differences in scar formation among the treatment groups. The mean healing times were ten days for the polyurethane dressings (Spandra and OpSite), 13 days for Petrolatum Gauze, and 16 days for the untreated group. Spandra was easier to apply and handle than OpSite. These findings suggest that synthetic gas-permeable dressings promote healing after cutaneous carbon dioxide laser surgery more effectively than conventional treatments of ointment-impregnated gauze or leaving the wound exposed to the air.

Animals↗
PubMed1986

Proposed method to study the factors affecting local control with combined external beam and interstitial implantation of mobile tongue and floor of mouth.

Twenty-seven patients with squamous cell carcinoma of the mobile tongue and floor of the mouth were treated with external beam and interstitial radiation. Good prognostic factors were T1N0, T2N0, superficial tumors, tumor shrinkage by 75% with external beam, and no apparent tumor clinically 2 months after treatment. On the other hand, T3N0, T1-3N1, and deeply necrotic tumors had a poor prognosis. We recommend using a flexible afterloading system to implant the initial local tumor volume (not just the residual nidus) that does not exceed 45 cm3. The minimum (reference) dose was prescribed to a surface 1/2 cm beyond the most peripheral rim of radioactive sources. For acceptable local control and complication rates, our suggested minimum (reference) doses are less than or equal to 7,500 rads for T1 (or a time-dose-fractionation [TDF] of 131-140), less than or equal to 8,000 rads for T2 (TDF of 131-140), and probably less than 8,500 rads for T3 (TDF of less than or equal to 150). These guidelines should be considered preliminary.

Brachytherapy↗
PubMed1986

Hemopoietic progenitor cell function after HLA-identical sibling bone marrow transplantation: influence of chronic graft-versus-host disease.

We examined hemopoietic reconstitution during the first 12 months post-transplant in 31 patients given high-dose cyclophosphamide, total body irradiation and an HLA-identical sibling marrow transplant for hematological malignancy. Unexpectedly, we found marrow CFU-gm and marrow CFU-e cells to be denser than normal throughout the first year post-transplant. While functionally adequate neutrophil and platelet counts were achieved in the first six weeks post-transplant, there were defects in hemopoietic progenitor cell function during the first year post-transplant. Although we could detect no influence from acute graft-versus-host disease (GVHD), chronic GVHD adversely affected the growth of both myeloid and erythroid blood progenitor cells.

Bone Marrow Cells↗
PubMed1986

Secretion of triglyceride lipase from rat hepatocytes in culture: modulation by insulin and phenobarbital.

Hepatic triglyceride lipase (HTGL) was measured in primary rat hepatocytes maintained for 3 days under three different culture conditions: basal medium, basal medium plus insulin, and basal medium plus insulin and phenobarbital. The activity of HTGL secreted by these cells was measured by treating intact cells with heparin; intracellular enzyme was subsequently measured in cell homogenates. Insulin stimulated intracellular triglyceride lipase activity by 48% and extracellular lipase by 30%. Phenobarbital, an enzyme-inducing drug, caused a further 15% increase in extracellular hepatic triglyceride lipase; whereas, the intracellular activity was reduced. The presence of insulin greatly stimulated the rate of enzyme secretion, and this rate was not notably affected by the presence of phenobarbital. After 3 days in culture, the short term (2-8 h) synthesis and secretion of enzyme from cultures treated with insulin or insulin plus phenobarbital were equally inhibited by cycloheximide. Monensin also inhibited enzyme secretion in both cultures and caused a similar increase in intracellular lipase activities. Insulin did not significantly affect the proportion of intracellular enzyme (17.7% basal vs. 15.8% insulin). On the other hand phenobarbital produced a 20-30% reduction in the proportion of intracellular enzyme (12.5 vs. 17.7% basal or 15.8% insulin). These findings suggest a drug-induced redistribution of triglyceride lipase.

Animals↗
PubMed1985

Episodic hyperhidrosis on the dorsum of hands.

A 21-year-old man presented with a 6-year history of episodic localized hyperhidrosis on the back of his hands. Results of the neurologic examination were normal. Profuse sweating of the affected skin was elicited by exercise, raising core temperature, direct heat, and intradermal injections of cholinergic drugs. Examination of the affected skin by electron microscopy and light microscopy with special stains and enzyme methods revealed prominent hyperplasia of otherwise normal eccrine sweat glands and ducts and increased surrounding stromal hyaluronic acid.

Adult↗
PubMed1985

Lack of correlation between nucleated bone marrow cell dose, marrow CFU-GM dose or marrow CFU-E dose and the rate of HLA-identical sibling marrow engraftment.

There was no correlation between the rate of marrow engraftment and the number of nucleated bone marrow cells infused into 50 HLA-identical sibling marrow graft recipients with haematological malignancy conditioned with cyclophosphamide and fractionated total body irradiation, and immunosuppressed with either cyclosporin (42 patients) or methotrexate (eight patients). Similarly, there was no correlation between the number of marrow CFU-GM or CFU-e infused into recipients immunosuppressed with cyclosporin. The data show that recipients of HLA-identical sibling marrow allografts conditioned with cyclophosphamide and total body irradiation require less than 3 X 10(8) nucleated bone marrow cells/kg recipient weight to ensure engraftment, and throw doubt on the relevance of measuring committed progenitor cells in the donor marrow to assess the likelihood of subsequent haemopoietic reconstitution after matched sibling transplantation.

Body Weight↗
PubMed1984

Management of gastrointestinal lymphoma.

A study was made of 65 patients with primary gastrointestinal (GI) lymphoma. The occurrence was 40 (62%) in stomach, 15 (23%) in the small intestine, and 10 (15%) in colorectum. The majority of patients had their histology classified according to Rappaport's classification. Diffuse histiocytic type had the worst prognosis (median survival 13.8 months), and nodular histology had the best prognosis. A modified staging system proposed by Blackledge et al. was used. Patients who had their disease confined to one viscus (Stage I) or with spread to regional lymph nodes (Stage II) had an excellent prognosis, with a 5-year survival of 87 and 67%, respectively. However, those who had distant nodal involvement (Stage III, e.g., para-aortic nodes) or spread to adjacent organs within the abdomen (Stage IV) had worse prognosis, with 5-year survival of 40 and 13%, respectively. In Stage I, radiotherapy alone was as effective as surgical resection. None of the 11 patients treated by radiotherapy alone had perforation or bleeding. The 5-year disease-free survival was 51%.

Adolescent↗
PubMed1983

Proximal gastric vagotomy, truncal vagotomy with drainage, and truncal vagotomy with antrectomy for chronic duodenal ulcer. A prospective, randomized controlled trial.

The relative merits of proximal gastric vagotomy (PGV), truncal vagotomy with drainage (TV + D), and truncal vagotomy with antrectomy (TV + A) in the treatment of chronic duodenal ulcer were evaluated and compared in 152 patients in a prospective, randomized and controlled clinical trial. One death occurred after TV + A, resulting in an operative mortality of 2% after gastrectomy and 0.7% for the entire series. After one to six years, stomal and duodenal ulcers proven by endoscopy occurred in eight patients after PGV (16%) and in six patients after TV + D (11.8%); the difference was not statistically significant (p greater than 0.5). One additional patient developed a gastric ulcer nine months after PGV. There was so far no ulcer recurrence after TV + A. Majority (13 patients) of the recurrent ulcers were discovered within three years after surgery. Patients after PGV experienced significantly less unwanted side effects than those after either TV + D or TV + A; particularly, dumping, epigastric fullness, and diarrhea. When the functional status was graded according to a modified Visick system that excluded ulcer recurrence, significantly more PGV patients were placed in the near-perfect grade (82.1%) than TV + A patients (58%). Patients after TV + D fared better than patients after TV + A; but the differences were not significant. However, when ulcer recurrence was included in the functional assessment, the advantage of PGV was lost.

Chronic Disease↗
PubMed1983

The clotting and staining of methylcellulose cultures of human hemopoietic cells.

We describe a technique for clotting, fixing and staining methylcellulose cultures of human hemopoietic progenitor cells. The entire cellular population of a 1-ml culture in a 35-mm plastic petri dish can be recovered and preserved permanently with this method. The technique also provides the opportunity for distinguishing between pure erythroid and mixed colonies, for examining cellular morphology without tediously picking individual colonies, and for terminating cultures on the appropriate day without the necessity of scoring on that same day.

Adult↗
PubMed1983

Carcinoma of the tonsillar area treated with external radiotherapy alone.

Seventy patients with carcinoma of the tonsillar area were treated with radiation therapy alone, all with a minimum follow-up of 3 years. Seventeen patients with stages I and II developed six recurrences and three were salvaged by surgery. Fifty-three patients with stages III and IV developed 24 recurrences, and only three could be salvaged by surgery. We conclude that radiation therapy is adequate for stages I and II carcinoma of the tonsillar area. Local control rate is satisfactory and surgical salvage is acceptable. Patients with advanced disease, Stages III and IV, have a poor survival rate with radiotherapy alone. Local recurrence is high and surgical salvage is inadequate. We have decided to offer selected patients with stages III and IV tonsillar carcinoma planned combined radiotherapy and surgery, in an effort to improve the survival rate.

Adult↗
PubMed1982

Progressive isolated segmental anhidrosis.

A patient had progressive segmental anhidrosis, which proved after extensive neurologic and autonomic workup to be an isolated abnormality. Intradermal acetylcholine produced localized sweating in areas of thermoregulatory anhidrosis five months after the onset of symptoms but failed to do so at two years. These findings are consistent with a preganglionic sympathetic lesion affecting a functionally defined subset of sympathetic cells and/or fibers. The alteration of the sudomotor response to intradermal acetylcholine during the course of the illness suggests that the diagnostic utility of pharmacologic sweat tests may be time dependent, limited to a relatively early period following onset of anhidrosis.

Acetylcholine↗
PubMed1982

Epidural morphine.

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Epidural Space↗