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Biomedical subjects

J Gates

Publications and source records attributed to J Gates.

52 records · Page 3Linked to original sources

Treatment of mouse L-cells with phorbol myristate acetate induces the secretion of a plasminogen activator inhibitor which binds to human and mouse urokinase and human tissue plasminogen activator.

1. Serum-free conditioned medium from L-cells or L-cells treated with the tumor-promotor phorbol myristate acetate (PMA) was analyzed for plasminogen activator (PA) and plasminogen activator inhibitor (PAI) activity. Conditioned medium from control or PMA-treated cells did not contain detectable PA activity when assayed by SDS-PAGE and zymography. 2. Conditioned medium from PMA-treated cells, but not control cells, contained a PAI of Mr = 40,000 da when assayed by reverse zymography. 3. The L-cell PAI formed SDS-stable complexes with purified human (homo sapiens) urokinase and tissue plasminogen activator, as well as, mouse (Mus musculus) urinary PA. 4. These results indicate that biochemical and immunological differences between human and mouse urokinase and human urokinase and human tissue plasminogen activator do not influence the interaction of the L-cell PAI with these enzymes.

Animals↗

Grocery store baking soda. A source of sodium bicarbonate in the management of chronic metabolic acidosis.

Oral sodium bicarbonate is used to treat metabolic acidosis in patients with renal tubular acidosis. Since infants and young children are unable to swallow tablets, those affected must ingest sodium bicarbonate in a powder or liquid form. Pharmacy-weighed sodium bicarbonate is expensive and inconvenient to obtain; some pharmacists are reluctant to provide it. We determined that the sodium bicarbonate contained in 8-oz boxes of Arm and Hammer Baking Soda was sufficiently constant in weight that, dissolved in water to a given volume, it yielded a quantitatively acceptable therapeutic solution of sodium bicarbonate at a cost of approximately 3 percent of that of pharmacy-weighed sodium bicarbonate. Grocery store baking soda can be a safe, economical, and convenient source of sodium bicarbonate for the treatment of chronic metabolic acidosis in infants and young children.

Acidosis, Renal Tubular↗

The mechanism of modification by propranolol of the metabolism of phosphatidyl-CMP (CDP-diacylglycerol) and other lipids in the rat pineal gland.

The mechanism underlying the alteration of phospholipid metabolism in rat pineal gland in vitro produced by propranolol and tertiary amine local anesthetics was investigated. 0.1 mM propranolol did not affect either the levels or specific activity of [32P]ATP in glands. In the presence of the drug, the incorporation of cytidine, but not of inorganic phosphate, into phosphatidyl-CMP (CDP-diacylglycerol) was dependent on the cytidine concentration. The incorporation of glycerol into phosphatidyl-CMP, phosphatidylinositol and phosphatidylglycerol was enhanced by propranolol, whereas labeling of phosphatidylcholine was decreased. When both 1 mM propranolol and 1 mM inositol were present, labeling of phosphatidylinositol was further increased, stimulation of phosphatidyl-CMP and phosphatidylglycerol labeling was reduced and incorporation into phosphatidylcholine and triacylglycerol was depressed. The incorporation of [3H]inositol into pineal lipids was also enhanced by propranolol. 10 microM propranolol inhibited rat liver phosphatidic acid phosphohydrolase by 50%, while local anesthetics were less potent in the decreasing order: dibucaine greater than tetracaine greater than lidocaine greater than procaine. The propranolol-induced accumulation of phosphatidyl-CMP was prevented by supplying adequate freely diffusible inositol in the medium. The phosphatidyl-CMP which accumulated was not utilized for the enhanced formation of phosphatidylinositol brought about by norepinephrine. The results indicate that propranolol and local anesthetics redirect pineal phospholipid metabolism in part by inhibition of phosphatidic acid phosphohydrolase.

Adenosine Triphosphate↗

Tuberous sclerosis in old age.

A case of tuberous sclerosis without seizures in a 64-year-old man has been presented. Typical cutaneous, retinal, and bone lesions were found, along with calcifications in the lateral and third ventricle. Tuberous sclerosis is generally seen in young patients, though its occurrence in elderly patients has been described in the literature. Diagnosis in the present case was delayed. It is hoped that reemphasis of this aspect of tuberous sclerosis will lead to a prompt diagnosis in similar cases.

Age Factors↗

Demonstration of inferior vena cava patency by retrograde azygous venography.

Gaining access for vena cavography may be difficult in patients with multiple venous occlusions. We report the use of selective azygous venography to demonstrate potency of the proximal inferior vena cava (IVC) when no alternative route was available and noninvasive techniques were not applicable. The proximal superior vena cava and the distal IVC were occluded.

Aged↗

Transfemoral repositioning of malpositioned central venous catheters.

PURPOSE: To determine the efficacy of the transfemoral vein approach to repositioning malpositioned central venous catheters. METHODS: During a 4(1/2)-year period, malpositioned central venous catheters were repositioned 91 times in 83 patients via the transfemoral vein approach. All repositioning was initially attempted with a Grollman catheter or other pigtail catheter and a tip-deflecting wire. If these techniques failed or the venous anatomy was unfavorable, gooseneck or long loop snares were used. RESULTS: During 48 repositionings, rotating a pigtail-type catheter alone was used successfully in 39 (81%). In 6 of 9 failures, the addition of a tip-deflecting wire also failed. A Grollman catheter and tip-deflecting wire were used initially in 39 repositionings (6 failures; 85% success). Successful repositioning required a snare in 8 (4 as the primary repositioning technique) and a long-loop technique in 5. All repositionings were ultimately successful and there were no complications. CONCLUSION: Central venous catheters can be repositioned consistently by the transfemoral route. Pigtail catheters or tip-deflecting wires alone are successful in over 80% of cases.

Catheterization, Central Venous↗

Primary biliary tract malignant melanoma.

Primary melanoma is rarely diagnosed in the biliary tract; only three cases of primary melanoma of the bile ducts have been reported previously. The skin and squamous mucous membranes are the most common primary sites. We report two patients who represent the fourth and fifth reported cases of primary bile duct melanoma.

Adult↗

Hepatic chemoembolization: effect of intraarterial lidocaine on pain and postprocedure recovery.

PURPOSE: To determine if intraarterial lidocaine reduces pain during and after chemoembolization, and whether it influences postprocedure recovery. METHODS: Two patient cohorts undergoing selective hepatic chemoembolization were compared. Chemoembolization was performed without lidocaine (control group) in 27 patients and intraarterial lidocaine was used (lidocaine group) in 29 similar patients. Objective changes in patient management were assessed. Pain reduction in 31 more procedures with lidocaine (total 60) was assessed and related to tumor type. RESULTS: During chemoembolization, intraarterial lidocaine reduced the need for additional intravenous analgesics from 69% to 19%. After chemoembolization the mean Dilaudid dose in the first 24 hr was reduced from 9.5 mg to 4.15 mg; accordingly, the mean length of hospital stay was reduced from 67.5 to 53.5 hr. During the day of chemoembolization, the mean oral fluid intake increased from 420 ml (control group) to 487 ml (lidocaine group); the percentage of patients taking solid food on the day of chemoembolization increased from 3% to 43%. CONCLUSION: Intraarterial lidocaine during chemoembolization reduces the severity and duration of pain after chemoembolization resulting in faster recovery thus reducing the length of hospitalization.

Anesthetics, Local↗

Factors affecting the clinical value of microscopy for acid-fast bacilli.

In order to assess the clinical value of microscopy for acid-fast bacilli (AFB), the results of 3,207 clinical specimens submitted for mycobacterial smear and culture were analyzed. Mycobacteria grew from 176 (5.5%) of the specimens, 95 (54%) of which were Mycobacterium tuberculosis. Although the overall sensitivity of the smear was low (33%), 65% of respiratory specimens yielding M. tuberculosis had positive AFB smears. Furthermore, 96% of patients with pulmonary tuberculosis from whom more than one specimen was processed had at least a single positive AFB smear. Smear sensitivity correlated well with quantitative growth; 89% of specimens yielding greater than or equal to 50 colonies per slant were smear positive. Specificity of the AFB smear was high; 89% of smear-positive specimens had positive cultures. After the results from culture-negative patients known to have active tuberculosis were eliminated from the analysis, the specificity of a positive smear rose to 98.3%. When the results of all specimens from each patient were considered in toto, the AFB smear had a predictive value of greater than or equal to 96%.

Aniline Compounds↗

Chemoembolization of hepatic neoplasms: safety, complications, and when to worry.

Chemoembolization of the liver for unresectable malignancy, although controversial, is being used with increasing frequency. Chemoembolization can be difficult, and there is great potential for causing complications. There are also findings after chemoembolization, particularly on computed tomographic scans, that may appear to indicate complications but are common and of no concern. Chemoembolization requires an understanding of the congenital and acquired variations of arterial anatomy that may be seen supplying the liver. Assessment of the patency of the portal vein is also required. An abnormal portal vein demands significant changes in technique to allow safe chemoembolization. Partial or complete occlusion of the portal vein is associated with significantly decreased survival but does not prevent a worthwhile response to chemoembolization and is not an absolute contraindication. The presence of chemoembolization material in the gallbladder is not uncommon; with the technique used by the authors, the chemoembolization material infrequently causes cholecystitis or gallbladder infarction. Extrahepatic chemoembolization material is commonly seen in other organs but usually does not cause problems, presumably because the dose deposited outside the liver is small compared with the dose delivered to the liver. Other complications include pseudocirrhosis, liver infarction and abscess formation, carcinoid crisis, hepatorenal syndrome, and liver rupture.

Antineoplastic Combined Chemotherapy Protocols↗

Optimized diagnostic angiography in high-risk patients with severe peripheral vascular disease.

Conventional arteriography remains the usual method for preoperative assessment of severe peripheral vascular disease (PVD). Unfortunately, many peripheral arteriograms are still performed with a suboptimal technique, which can cause significant diagnostic errors in patients with severe PVD. A suboptimal technique may be due to poor collimation (causing incorrect exposure and incorrect gray scale), excessive patient-film distance (magnification unsharpness), inadequate volume or density of contrast material, poor contrast resolution (screen-film arteriography), nonselective injection, patient movement, and pressure from restraints or incorrect patient position (failure to profile lesions, pseudo-occlusion from external pressure or plantar flexion). The technique of selective digital subtraction arteriography (DSA) allows one to avoid these errors. The superior contrast resolution of DSA allows use of lower concentrations of contrast material. Selective injection into the external iliac artery allows proper positioning and improves image quality. Demonstration of distal vessels is best achieved by using biplane arteriography. For patients with severe resting ischemia, especially those with diabetes, high-quality selective DSA is essential to ensure that all distal vessels suitable for distal bypass grafting are identified. When properly performed, selective DSA remains the investigation of choice for reliably demonstrating arterial anatomy in high-risk patients with severe PVD.

Angiography, Digital Subtraction↗