Biomedical subjects

A Fotopoulos

Publications and source records attributed to A Fotopoulos.

22 records · Page 2Linked to original sources

PubMed1977

Evaluation of Tc-99m pyridoxal-phenylalanine as a hepatobiliary agent. Part 2. Clinical tests.

Twenty-four patients with normal or diseased hepatobiliary systems were subjected to a clinical trial in order to evaluate Tc-99m pyridoxal-phenylalanine as a biliary imaging agent. The investigation was combined with i.v. cholecysto-cholangiography in most cases, and the results were compared. It is concluded that qualitative information derived from conventional i.v. cholangiography is better in demonstrating the normal biliary tree or gallstones. The radiotracer techniques, however, are valuable in dynamic studies of Oddi's sphincter, in showing patency of biliary by-pass procedures, and in differentiating hepatocellular from obstructive jaundice.

Aged↗

PubMedDate not supplied

Pressure-flow relationships for packed beds of compressible chromatography media at laboratory and production scale.

Pressure drop across chromatography beds employing soft or semirigid media can be a significant problem in the operation of large-scale preparative chromatography columns. The shape or aspect ratio (length/diameter) of a packed bed has a significant effect on column pressure drop due to wall effects, which can result in unexpectedly high pressures in manufacturing. Two types of agarose-based media were packed in chromatography columns at various column aspect ratios, during which pressure drop, bed height, and flow rate were carefully monitored. Compression of the packed beds with increasing flow velocities was observed. An empirical model was developed to correlate pressure drop with the aspect ratio of the packed beds and the superficial velocity. Modeling employed the Blake-Kozeny equation in which empirical relationships were used to predict bed porosity as a function of aspect ratio and flow velocity. Model predictions were in good agreement with observed pressure drops of industrial scale chromatography columns. A protocol was developed to predict compression in industrial chromatography applications by a few laboratory experiments. The protocol is shown to be useful in the development of chromatographic methods and sizing of preparative columns.

Biotechnology↗

PubMedDate not supplied

Results of treatment of experimental pulmonary embolism, as determined by radioactive microspheres.

In this experimental study seventeen dogs subjected to pulmonary embolism were treated with either saline, heparine or streptokinase. Regional blood distribution was calculated in both, the healthy and infarcted lung tissue by means at the sequental injection of radioactive microspheres. Results of fibrinolytic treatment compare favourable over heparine or saline administration.

Animals↗

PubMedDate not supplied

Perforated diverticulitis: a surgical dilemma.

Thirty-eight patients, 18 males and 20 females (mean age 61 years) have been operated on for perforated diverticulitis, over the past 14 years. We assigned the patients into stage A (n = 12) when the inflammation was confined to the mesosigmoid folds, stage B (n = 16) when an intraabdominal abscess was walled off and stage C (n = 10) when a generalized peritonitis had developed. Resection of the perforated sigmoid was carried out in 24 patients either as Hartmann's procedure (n = 18) or with primary anastomosis (n = 6). The mortality rate in this setting was 0.0% and 16.6% respectively. In 14 patients, no resection was carried out in 24 patients either drainage and colostomy (n = 10) or only drainage (n = 4) with corresponding mortality rate 30% and 25%. Mortality rate in relation to the stage was: Stage A 16.16%, Stage B 12.5% and Stage C 10%. The higher mortality rate in stage A and B was due to the fact that less radical operations were carried out. Four of our five deaths in all stages occurred in patients in whom the perforated sigmoid was not resected. In conclusion resection of the perforated sigmoid with or without primary anastomosis regardless of the stage of the disease is recommended.

Adult↗