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Biomedical subjects

R Zeman

Publications and source records attributed to R Zeman.

13 recordsLinked to original sources

Safety and effectiveness of Lithostar shock tube C in the treatment of urinary calculi.

Over 14 years of clinical use of extracorporeal shockwave lithotripsy (SWL), great technical modifications resulted in the development of many second-generation lipthotripters. The Siemens Lithostar machine, with its standard shockwave tube, was introduced in 1986. The objective of this study was to assess the safety and effectiveness of the newly proposed Lithostar shock tube C in the treatment of urinary calculi. Between July 1992 and August 1993, 319 patients (214 males and 105 females, average 49.7 years) with 433 renal or ureteral stones or both were treated at five centers in Canada and the United States. Most of the stones (72%) were located in the kidneys, while 28% were located in the ureters. Most (81%) of the treated sides (side = kidney and ureter) presented with single stones, 11% presented with two stones, and 8% presented with three or more stones. The average stone burden was 13.6 mm. The average duration of treatment for the whole population of patients was 39.3 minutes using an average number of shockwaves of 3633 in a minimum and maximum energy setting of 0.11 and 3.82, respectively. The majority of treatments (92%) were performed without anesthesia. Fragmentation was achieved in 93.5% of treatments, with a 3-month stone-free rate of 62.5% and a success rate (stone free or fragment < 5 mm) of 72%. Auxiliary procedures were necessary in conjunction with 108 treatments, and most of them were in form of catheter/stent placement. Treatment applied on a separate occasion to different stones but in the same collecting system (either a kidney or a ureter) were considered retreatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

The use of single photon emission computerized tomography in neuropsychiatric SLE: a pilot study.

OBJECTIVE: To test the sensitivity of single photon emission computerized tomography (SPECT) in detecting brain abnormalities in cases of definite active neuropsychiatric systemic lupus erythematosus (NPSLE) in a blinded, prospective pilot study. METHODS: Fourteen patients fulfilling at least 4 of the American College of Rheumatology criteria for the classification of SLE plus positive serology manifested by either elevated DNA binding or decreased serum complement and a recent neuropsychiatric event were evaluated with cerebral SPECT using hexa-methyl-propylene-amine-oxime labeled 99Tc. Secondary causes such as infection, uremia, hypertension, drugs, and metabolic abnormalities were excluded. Patients underwent brain scan and electroencephalogram (EEG) for comparison. When clinically indicated, CT scan, magnetic resonance imaging, angiography, and lumbar puncture were performed. RESULTS: SPECT scan abnormalities were noted in 12/14 patients and brain scan was abnormal in 12/14 patients. SPECT and brain scan were in accordance in 12/14 patients (11 patients both positive and 1 both negative) and the combination of SPECT and brain scan yielded 13/14 positive results. In the 3 patients with headache, SPECT scan was negative in 2/3, despite positive EEG and one with a positive brain scan. The positive SPECT in the patient with headache showed an old cerebrovascular accident (CVA), which was confirmed by CT scan. The most consistent CT finding was cortical atrophy; however, SPECT identified a lesion in the occipital cortex in a patient with seizure, and a lesion in the basal ganglia in a patient with ataxia. CONCLUSION: In clinically and serologically active NPSLE, SPECT is a sensitive diagnostic tool. When further stratifying NPSLE into focal (seizure, ataxia, CVA) and diffuse (headache, organic brain syndrome, psychosis), SPECT appeared to be sensitive for focal disease and for most diffuse manifestations, with the exception of headache. The high sensitivity of SPECT in patients with true, positive NPSLE merits further controlled studies in unselected patients with SLE.

Adult

Cell aggregates of Escherichia coli with benzylpenicillin amidase activity.

Intact cells Escherichia coli CCM 2843, exhibiting substantial benzylpenicillin amidase activity, were bound mutually with supporting waste microbial cells, native or treated, to obtain an inexpensive biocatalyst for the production of 6-aminopenicillanic acid (6-APA). The bond was effected by glutaraldehyde (GA) and Sedipur CL-930 (PEI), without any carrier. The optimal concentration of GA was 2%, that of PEI 1%. The optimal biocatalyst was obtained by immobilization of productive cells with their fragments at a mass ratio of 4:1. The cell aggregates were used for hydrolysis of potassium benzyl-penicillin at a concentration of 5% to 6-APA. After 25 repeated batch conversions the degree of conversion did not decrease; its average value was 96.4%.

Bacterial Adhesion

Enzyme synthesis of L-tryptophan.

Enzyme synthesis of tryptophan from indole, pyruvate and ammonium salts was studied using Escherichia coli cells exhibiting a significant tryptophanase activity. In addition to the effect of cultivation medium composition and cultivation conditions, factors affecting the course of the conversion were investigated. Production of 32.4 g/L of L-tryptophan was reached after 48 h under optimal conditions.

Acetates

Radiotherapy in the management of pancreatic islet cell tumors.

Malignant islet cell tumors are commonly treated with surgical resection. Chemotherapy is reserved for residual, unresectable, or metastatic disease. The role for radiotherapy has not been clearly defined. This article describes three cases of advanced islet cell tumors treated effectively with radiotherapy. This experience, in addition to that from other published reports, suggests that radiotherapy is a useful mode for treating advanced islet cell carcinoma.

Adenoma, Islet Cell

Ultrasound demonstration of anicteric dilatation of the biliary tree.

This report presents eight patients with dilatation of the biliary tree, six of whom had no clinical or laboratory evidence of biliary tract disease except for elevated levels of serum alkaline phosphatase. In two patients, dilatation was caused by obstruction of only one hepatic duct; in three, it was caused by a pancreatic tumor; and in three, it was associated with gallstones which exercised a ball-valve effect, producing intermittent obstruction. The elevation of the alkaline phosphatase level in six of these patients suggests that it is a more sensitive indicator of biliary tract obstruction than the serum bilirubin level is. The recognition of biliary dilatation in one or both lobes of the liver should lead to a careful examination, with ultrasound or another modality, of the porta hepatis, common bile duct, and pancreas.

Aged