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T Roy

Publications and source records attributed to T Roy.

68 records · Page 4Linked to original sources
PubMed1981

Continuous measurement of DTPA-clearance in extracorporeal detoxification circuits.

A new method for investigating clearances is described. DTPA labelled with technetium 99m (MW: 496 daltons) is used as an agent to be measured. Continuous determination of the DTPA-clearance is possible in extracorporeal detoxification circuits including dialyzers, hemofilters and hemoperfusion columns. As an example, DTPA-clearances are given for two different dialyzers. In comparison to clearance measurements of peak 7, DTPA-clearance was very similar to that obtained for peak 7.

Autoanalysis↗
PubMed1980

[Technics and indications for hemofiltration treatment].

Technique, possibilities of application, advantages and disadvantages of haemofiltration are described. A convective mass transport underlies the method. By this means the elimination of molecules of different size takes place with the same speed and the removal of so-called middle molecules is performed more effectively than in the usual method of dialysis.

Acute Kidney Injury↗
PubMed1980

Effect of bile salt-binding resins on the morphology of rat jejunum and colon. A scanning electron microscopy study.

One mechanism suggested to account for the hypocholesteremic effect of dietary fibers is their ability to sequester bile salts. Since bile salts have been found to alter intestinal structure, the morphological effects of several commonly used, xenobiotic, bile salt-binding agents was investigated. Wistar rats were fed a purified stock diet, ad libitum, for 6 weeks containing either 2% cholestyramine, 2% colestipol, or 2% DEAE-Sephadex. The bile salt-binding capacity of these substances was tested in vitro using taurocholate and glycocholate. The effect of in vivo feeding of the resins was to evoke ultrastructural topographical deviations from control appearance in both jejunal and colonic mucosae. Colonic cell injury was more severe than that observed in the jejunum of both colestipol- and DEAE-Sephadex-fed animals while the reverse was true for the rats fed cholestyramine. The degree of distortion in each condition was positively correlated with the extent of bile salt-binding capability in vitro. The rank order of both effects in terms of increasing severity was DEAE-Sephadex less than colestipol less than cholestyramine.

Animals↗
PubMed1978

Comparative intestinal and colonic absorption of [4-14C] cholesterol in the rat.

[4(-14)C] Cholesterol was administered as an aqueous emulsion with triolein and dry non-fat milk either directly into the upper duodenum or into the ileocaecal junction of lymph duct cannulated rats. Lymph flow rates were similar in the two groups of animals. Whereas ca. 53% of the administered tracer dose of cholesterol was absorbed when introduced into the upper small intestine, only 0.06% appeared in lymph when administered into the caecum. Furthermore, less than 0.01% of the administered isotope was detected in urine and blood. The data demonstrate that the large intestine does not contribute significantly to the absorption of exogenous cholesterol in the rat.

Animals↗
PubMed1978

Dietary fiber and lymphatic absorption of cholesterol in the rat.

The indirect effects of short-term (3-day) feeding of several types of dietary fiber and nonnutritive materials on the subsequent absorption of cholesterol has been investigated in thoracic duct cannulated rats. Absorption was studied at timed intervals over 24 hr after duodenal introduction of a tracer dose of cholesterol at least 20 hr after the last feeding. In animals fed for 3 days with diets containing cholestryamine, bran, or cellulose, cholesterol absorption was significantly less than in control animals maintained on rat chow. Rats fed for 3 days with an alfalfa-containing diet showed large variations in cholesterol absorption that were not significantly different from controls. However, after 5 weeks, rats on the alfalfa diet showed a marked reduction in lymphatic absorption of the tracer sterol. These indirect effects of cholestryamine and fibers on cholesterol absorption were not attributable to a common mechanism; i.e., differences in transit times that were not significant, or dirrect binding of bile acids and cholesterol by the test materials.

Absorption↗
PubMed1975

Electronic spectra and electronic structures of some antimicrobials derived from proflavine.

The shifts in the absorption and fluorescence spectra of 3-aminoacridine, proflavine, acridine orange, and acridine yellow were employed to show that the singly charged cations, the predominant species at biological pH, exist in the ground state in the amino form. In the lowest excited singlet state, however, the monocations of the diaminoacridines have the imino structure, a conclusion supported by the relative ground- and excited-state pKa values of the reactions of the monocation with H-+. The ground-state amino structure has its positive charge concentrated at the heterocyclic nitrogen atom, a fact that is of primary importance in determining the geometry of binding to DNA.

Acridines↗
PubMedDate not supplied

Preparations of synthetic phospholipids promote procoagulant activity on damaged vessels: studies under flow conditions.

BACKGROUND: The possibility of developing synthetic platelet substitutes that could promote hemostasis with prolonged shelf-life and increased safety is an appealing one. STUDY DESIGN AND METHODS: Preparations containing synthetic phospholipids were incorporated into blood samples (1.15 mg/mL) in which platelets and white cell counts had been experimentally reduced by a filtration procedure. Vesicles containing phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), or combinations of PC and PE and of PC and PS were tested in this system. Blood was recirculated (10 min; shear rate, 250/sec) through a perfusion chamber containing vascular segments. The ability of the various phospholipid preparations to promote fibrin formation on the damaged subendothelium was evaluated morphometrically and expressed as the percentage of fibrin coverage. Generation of thrombin in the system was monitored through the measurement of prothrombin fragments 1 and 2. RESULTS: Vesicles containing PC, PI, PE:PC (1:1), or PS:PC (1:3) increased fibrin deposition on the subendothelium (64.5 +/- 9.8%, 32.7 +/- 6.3%, 58.3 +/- 6.5%, and 46.6 +/- 15.2%, respectively; p < 0.01 vs. 11.5 +/- 1.2% in thrombocytopenic blood). Vesicles containing PE, PS, or PS:PC (3:1) did not show procoagulant effect. CONCLUSION: Synthetic phospholipid preparations promote a local procoagulant activity at sites of vascular damage when they are incorporated into thrombocytopenic blood maintained under flow conditions.

Animals↗
PubMedDate not supplied

Quantification of posterior capsule tightness and motion loss in patients with shoulder impingement.

The relationship between posterior capsule tightness and dysfunction has long been recognized clinically but has not been biometrically quantified. The purpose of this study was to quantify changes in range of motion and posterior capsule tightness in patients with dominant or nondominant shoulder impingement. Measurements of posterior capsule tightness and external and internal rotation range of motion were made in 31 patients with shoulder impingement and in 33 controls without shoulder abnormality. Patients with impingement in the nondominant arm had increased posterior capsule tightness and decreased internal and external rotation range of motion compared with controls. Patients with impingement in their dominant arm had increased posterior capsule tightness and reduced internal rotation range of motion but no significant loss of external rotation range of motion compared with controls. Posterior capsule tightness in impingement patients showed a significant correlation with loss of internal rotation range of motion. Patients with shoulder impingement in their nondominant arm had a more global loss of range of motion compared with patients having impingement in their dominant arm. We believe we have described a valid clinical measurement for identifying posterior capsule tightness in patients with shoulder impingement.

Adult↗
PubMedDate not supplied

Semifluorinated alkanes--a new class of compounds with outstanding properties for use in ophthalmology.

Semifluorinated alkanes, R(F)R(H), have a perfluorocarbon and a hydrocarbon segment in the molecule. R(F)R(H) are physically, chemically and physiologically inert, colorless, laser stable liquids with substantially reduced densities--between 1.1 and 1.7 g/cm3--and very low surface and interface tensions. R(F)R(H) are useful for unfolding a retina or for permanent tamponade. They are soluble in perfluorocarbon liquids (PFCL), hydrocarbons and silicone oils. For the first time residues of silicone oil can be extracted from the eye because R(F)R(H) are solubilizers for PFCLs and silicone oils, so they can be used as solvents or solubilizers for drugs and medicaments. Therefore R(F)R(H) are excellent candidates for use in the ophthalmic field.

Animals↗
PubMedDate not supplied

Gastro-duodenal mucosal changes associated with low-dose aspirin therapy: a prospective, endoscopic study.

OBJECTIVES: The association of low-dose aspirin use and gastro-intestinal bleeding is well described. However, the gastroduodenal mucosal changes associated with low-dose aspirin therapy have not been properly evaluated. We undertook a prospective, endoscopic study to evaluate gastro-duodenal mucosal lesions produced by low-dose aspirin. METHODS: Forty-seven patients with non-hemorrhagic cerebral infarct or transient ischemic attacks and normal upper gastrointestinal endoscopy were randomized to receive either enteric-coated (n=25) or plain (n=22) aspirin (150 mg/day). Follow-up endoscopy was done at 2, 4 and 8 weeks; gastro-duodenal mucosal lesions, if present, were scored. Forty-seven patients with hemorrhagic infarct who were not treated with aspirin served as controls. RESULTS: Twenty eight (60%) of 47 patients receiving aspirin had mucosal lesions; stomach alone was the most frequent site (32%), followed by both stomach and duodenum (23%). Frequency of mucosal changes in the stomach at 8 weeks (19%) was significantly lower (p<0.05) than those at 2 weeks (53%) and 4 weeks (55%). Coated (56%) and plain (63.6%) aspirin induced mucosal lesions with similar frequency. CONCLUSION: Administration of low-dose aspirin, either plain or enteric-coated, induces endoscopic gastro-duodenal mucosal lesions in a large majority of patients. The frequency of damage decreased after 8 weeks of therapy.

Adult↗
PubMedDate not supplied

The effect of cooled dialysate on thermal energy balance in hemodialysis patients.

The authors have monitored extracorporeal thermal energy balance using continuous in-line arterial and venous temperature and blood flow measurements. Use of dialysate at 37 degrees C resulted in a mean heat energy gain of 83 +/- 61 cal/min, whereas dialysate at 34 degrees C produced a loss of 463 +/- 121 cal/min. Monitoring extracorporeal thermal energy balance during cooled-dialysate hemodialysis will facilitate the use of feedback loops for dialysate temperature control in order to maximize hemodynamic stability while reducing discomfort. This methodology also may be helpful in assessing the metabolic effects of protein intake, high flux dialysis, membrane biocompatibility, and adequacy of dialysis in relation to thermal energy balance.

Adult↗