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Biomedical subjects

C S Ho

Publications and source records attributed to C S Ho.

At least 127 records · Page 7Linked to original sources
PubMed1988

Oxygen diffusion coefficients in commonly used topical semisolid creams.

The objective of this paper is to determine oxygen diffusion coefficients, permeabilities, and solubilities in a commonly used o/w topical ointment (similar to USP XXI hydrophilic ointment) and four commercial 1% anthralin creams. A new method developed by Ju and Ho in 1986 by applying a coupled steady-state and unsteady-state analysis for oxygen diffusion through a thin layer of test material on the surface of a membrane-covered polarographic oxygen electrode was used in the study. The results indicate that oxygen diffusion coefficients decrease with an increasing petrolatum concentration in o/w topical creams. The oxygen diffusion coefficients in four commercial creams containing 1% of extremely oxygen-sensitive anthralin were also determined using the same method. The information generated in this study can lead to a better understanding of the diffusion transport mechanism of oxygen in the topical creams and, thus, be useful to the formulation design of oxygen-sensitive drugs in semisolid dosage forms intended for topical, ophthalmic, and parenteral use.

Administration, Topical↗
PubMed1988

Pancreatic pseudocysts drained through a percutaneous transgastric approach: further experience.

Percutaneous transgastric placement of a drainage catheter under ultrasonographic and fluoroscopic guidance was performed in 12 patients with pancreatic pseudocysts. Complete resolution of the pseudocysts was obtained in eight patients, and the result was indeterminate in one patient due to early death from unrelated causes. Surgical intervention followed in two patients, one with a multiloculated pseudocyst that was incompletely drained and another with a pseudocyst that became infected following drainage. In one patient with metastatic tumor to the head of the pancreas the pseudocyst resolved initially, but a pseudocyst later recurred. There were no pancreaticocutaneous fistulas or other major complications. The transgastric route of pseudocyst drainage is safe and effective, and it offers a low risk of recurrence and fistula formation.

Adult↗
PubMed1988

Body composition and plasma creatine kinase activity.

Plasma creatine kinase (CK) activity and lean body mass (LBM) (by anthropometry) were measured in 120 women (20-82 years) and 70 men (20-82 years). Plasma CK activity and LBM was higher in men than in women. In men plasma CK activity was significantly correlated (product moment correlation coefficient) with LBM and negatively with age. In women plasma CK activity was significantly correlated with age. Partial correlation coefficient calculation showed a significant correlation between plasma CK and LBM both in men and in women. We conclude that in healthy subjects the plasma CK activity is related to LBM, but the LBM is not a major determinant of plasma activity in healthy subjects.

Adult↗
PubMed1988

Magnetic resonance imaging, computed tomography, and radionuclide scintigraphy in detection of liver metastases.

A series of 100 patients with suspected hepatic metastases was studied with magnetic resonance (MR), unenhanced computed tomography (CT), and radionuclide (RN) scintigraphy. Each set of images was read by three clinicians using a five-point scale to allow receiver operating characteristic (ROC) analysis using truth data derived from clinical review. Performance was measured by the areas under the ROC curves (0.940 +/- .018 for MR, 0.951 O +/- .013 for CT and 0.943 +/- .013 for RN) which were statistically not significantly different. We conclude that at their present level of development these three diagnostic examinations have equivalent performance and that MR is not superior in the detection of hepatic metastases.

Evaluation Studies as Topic↗
PubMed1987

Biliary lithotripsy with a mechanical lithotripter.

A simple device for easy and safe mechanical disintegration of hard and large (1-2.5 cm in diameter) biliary calculi, the mechanical lithotripter, has been designed for use with a Dormia or similar type of basket. This device is capable of generating a steady increase in tension in the basket wires, which in turn breaks up the calculus. It may be introduced through a T-tube tract or by a percutaneous transhepatic approach. The lithotripter has been successfully tested in vitro with ten mixed gallstones obtained soon after cholecystectomy and has been successfully employed in six patients with biliary calculi, three with T tubes and three without. In the latter three patients, a percutaneous transhepatic biliary procedure was performed to enable introduction of the lithotripter. There were no complications.

Adult↗
PubMed1987

Complications of percutaneous biliary drainage: benign vs malignant diseases.

Percutaneous transhepatic biliary drainage is used to treat a variety of benign and malignant biliary diseases. Although several investigators have reported on the number of complications associated with the use of this procedure in malignant disease, none has determined specifically the number associated with its use in benign disease. Differences in the number of procedure-related complications and deaths were examined in 206 patients with benign or malignant biliary diseases who underwent percutaneous transhepatic biliary drainage at the Toronto General Hospital during a 40-month period. Of these, 54 had benign and 152 had malignant biliary diseases. The prevalences of procedure-related major complications and deaths were 2% and 0%, respectively, in the benign group vs 7% and 3%, respectively, in the malignant group. These differences can be attributed to the shorter periods of drainage required and the generally better health of patients in the benign group. These findings suggest that percutaneous transhepatic biliary drainage can be performed with substantially fewer complications in patients with benign biliary diseases compared to those with cancer. Previously reported data on complications were derived from patient populations with preponderantly malignant obstructions and cannot be extrapolated to patients with benign diseases.

Adult↗
PubMed1987

Oxygen transfer in the corneal-contact lens system.

The clinical results of contact lens wearers indicate that materials which theoretically are adequate to prevent corneal hypoxia and edema do not perform optimally under actual wearing conditions. Optimization of the cornea-tear-lens system requires an analysis of the modes of oxygen transport, mass transfer resistances, and characteristic dimensions. The lens properties are a function of polymer composition. Thus, investigations for ideal lens materials may result in limitless test copolymers and graft polymers of siloxane, methylmethacrylate, 2-hydroxyethyl-methacrylate, vinylpyrollidone, vinylacetate, and cellulose acetate butyrate of varying degrees of cross-linking and crystallinity. In an attempt to channel research efforts, this review will state the developments to date and the desirable properties of an optimal cornea-tear-lens system. The logic should encompass a theory and model whereby parameters are identified and varied within satisfactory physiological limitations, and experiments which provide data indicative of the in vivo conditions. The parameters must reflect the inherent transport properties of the corneal-contact lens system. Contact lenses may be categorized as soft, gas-permeable rigid/hydrophobic flexible, or hard. The major differences between these three categories are the properties: equilibrium water content or degree of hydration, tendency for water pervaporation and/or dehydration, surface hydrophobicity, thermal conductivity, oxygen diffusivity and solubility, lens thickness, rest height over corneal tear, flexibility, lens mobility over the cornea, cross-linking, crystallinity, stagnant boundary layer resistances, and manufacturing processes. Aside from complications presented by lens coatings and cleansing solutions, the most common problems experienced by lens wearers include corneal edema, dehydration involving the lens and the cornea, "blurry" vision due to localized corneal anoxia, debris trapped under the lens, and deposits on th surface of the lens. All of the aforementioned phenomena are either explicitly or implicitly associated with transport processes through and around the lens. Convection of tear fluid under a lens during a blink, diffusion of oxygen and water through the lens and the stagnant boundary-layer effect for mass transfer in the tear between blinks, and the overall nonisothermal effects on the transport of oxygen and water between the cornea and ambient conditions are reviewed.

Biocompatible Materials↗
PubMed1986

Percutaneous transhepatic sphincterotomy in the management of biliary tract disease.

This report describes a novel modification of existing transhepatic techniques and illustrates successful relief of mechanical obstructive jaundice in 2 patients in whom surgical or endoscopic intervention was contraindicated or impossible. In each, percutaneous transhepatic cholangiogram (PTC) was performed in the usual manner. A standard endoscopic papillotome was then advanced across the stricture into the duodenum. Sphincterotomy was performed at the 11 to 1 o'clock position using blended current for 3-4 seconds. Repeat cholangiography showed successful decompression of the biliary tree in both patients. No morbidity or mortality was directly attributable to percutaneous transhepatic sphincterotomy in these patients. This technique offers a safe and therapeutic alternative to biliary tract obstruction, and should be considered in selected patients who are not candidates for surgery or endoscopy.

Aged↗
PubMed1986

Gastric hemorrhage complicating percutaneous transgastric jejunostomy.

The first occurrence at the authors' institution of serious gastrointestinal tract hemorrhage complicating percutaneous transgastric jejunostomy and its management by a modified technique are reported. The 0.7% frequency of this complication (one in 130 procedures) compares favorably with the frequency of hemorrhage reported for surgical gastrostomy (0.9%-1.4%). Percutaneous transgastric jejunostomy represents no greater risk of hemorrhage than does surgical gastrostomy and should continue to be an alternative to the latter procedure.

Aged↗
PubMed1986

Fine-needle aspiration biopsy of adrenal tuberculosis.

Adrenal tuberculosis remains an important cause of Addison's disease. Acute tuberculosis adrenalitis may produce mass-like enlargement of the glands which requires differentiation from primary or secondary neoplastic disease. Using percutaneous fine-needle aspiration biopsy, the authors made the diagnosis of tuberculosis adrenalitis in two patients who presented with Addison's disease; and enlarged adrenal glands seen using computed tomography.

Adrenal Gland Diseases↗