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Biomedical subjects

A Dekker

Publications and source records attributed to A Dekker.

At least 145 records · Page 8Linked to original sources

Effects of thyroid-stimulating hormone on adenyl cyclase activity and intermediary metabolism of "cold" thyroid nodules and normal human thyroid tissue.

"Cold" thyroid nodules do not concentrate (131)I before or after thyrotropin (TSH) administration. In an attempt to elucidate the reason for this TSH unresponsiveness, the effect of TSH in vitro on several metabolic parameters was studied in 11 "cold" thyroid adenomas, 2 medullary carcinomas, and in the surrounding normal thyroid tissue. Basal adenyl cyclase activity, glucose-1-(14)C oxidation, and (32)P incorporation into phospholipids were significantly greater in the adenomas than in the adjacent normal thyroid; basal cyclic 3',5'-adenosine monophosphate (cyclic AMP) concentration and adenine-(3)H incorporation into (3)H-labeled cyclic AMP were not different. In adenomas as well as normal thyroid, all parameters responded significantly to in vitro TSH stimulation. The response to TSH of adenyl cyclase activity and (32)P incorporation was enhanced in adenomas compared with that of the adjacent normal thyroid. These differences were not explained by an increased cellularity of the adenomas. Medullary carcinomas did not respond to TSH in any of the above parameters. The studies demonstrate an intact, TSH-responsive adenyl cyclase-cyclic AMP system in the adenomas and, accordingly, imply the presence of receptor sites for TSH on the cells of the adenoma. The failure of such nodules to concentrate (131)I may be owing to a subsequent impairment in the expression of cyclic AMP action on iodine metabolism.

Adenine↗

Malignant lymphoma of the thyroid gland: a clinicopathologic study.

This study reviews 21 cases of thyroid lymphoma diagnosed between 1969 and 1980. The thyroid gland was the primary site in all but two cases. The 20 patients with non-Hodgkin lymphoma had a mean age of 66 years, 75% were women, and all were Caucasian. A rapidly growing thyroid mass with hoarseness, dysphagia, and difficulty in breathing was the initial finding. Most patients had diffuse histiocytic lymphomas. Associated Hashimoto thyroiditis was found histologically in 57% of the cases. Using the immunoperoxidase stain method on tissue sections, intracytoplasmic monoclonal immunoglobulin was demonstrated in 5 of 15 cases. All but two patients received radiation therapy, and 13 received chemotherapy. The median survival was 8 months; 20% died of unrelated causes and 32% are alive (average duration: 27 months). Dissemination, after local control by radiation therapy, was the leading cause of death. The prognosis was better in men, in patients under the age of 65 years, and in those patients who, on biopsy, did not have involvement of the extrathyroid soft tissue or regional lymph nodes.

Adenocarcinoma↗

Adult liver transplantation: an analysis of the early causes of death in 40 consecutive cases.

One hundred twenty-nine adult patients who received an orthotopic liver transplantation and survived at least 24 hr after surgery were evaluated. During the period of follow-up, 48 of the 129 patients (37%) died. Only 40 of these 48 patients died at our institution and were included in this study. Seventeen of the 40 deaths (42.5%) occurred during the first month after orthotopic liver transplantation and 30 of the 40 deaths (75%) occurred during the first 60 days post-orthotopic liver transplantation. Death was related to infection in 21 cases (52.5%), to multiorgan failure in 8 (20%) and to uncontrollable rejection in 3 (7.6%). The remaining eight deaths (20%) were attributed to a variety of other causes. Eleven of the 21 deaths related to infection (52%) occurred during the first month after orthotopic liver transplantation. Bacterial sepsis was the leading cause of death and accounted for 17 of the 21 deaths (81%) in which infection was present at the time of death. The most frequently isolated bacteria were Pseudomonas and other enteric Gram-negative bacilli. Three patients had complete occlusion of the hepatic artery of the grafted liver. Six patients developed massive infarction of the liver despite patent vascular anastomoses. Histological signs of rejection were seen in 9 of the 31 patients autopsied (29%), but in only 3 of these (9.6%) was rejection the principal cause of death. The biliary anastomoses were patent in all 31 cases examined at autopsy.

Adolescent↗

Prevention of bacteremia caused by alpha-hemolytic streptococci by roxithromycin (RU-28 965) in granulocytopenic patients receiving ciprofloxacin.

We previously demonstrated that ciprofloxacin prevents infections caused by gram-negative bacilli in patients with granulocytopenia. However, in patients with intensive cytotoxic treatment leading to severe mucosal damage a high incidence of bacteremias caused by alpha-hemolytic streptococci was seen. In the present study 45 consecutive patients undergoing intensive cytotoxic treatment received a short course of roxithromycin (10 days) in addition to ciprofloxacin for prevention of bacteremias caused by alpha-hemolytic streptococci. The results of this study were compared with the results obtained in previous comparable patients receiving ciprofloxacin alone. During the days with addition of roxithromycin no infections caused by alpha-hemolytic streptococci occurred, while in the control group of 80 patients 16 bacteremias (20%) were seen. Although roxithromycin was shown to antagonize bactericidal action of ciprofloxacin on gram-negative bacilli in vitro, in vivo study based on serum bactericidal titers and on results of surveillance cultures showed no antagonistic interactions.

Acute Disease↗

Prevention of infection in the neutropenic patient.

All adult patients with acute nonlymphocytic leukemia--either first diagnosed or in relapse--who were admitted to University Hospital (Utrecht) between 1 December 1978 and 1 November 1980 were randomly assigned to a control group or to a group that received trimethoprim-sulfamethoxazole (TMP-SMZ) prophylactically; those admitted between 30 November 1980 and 1 December 1981 received a regimen of TMP-SMZ plus colistin; those admitted from 1 December 1981 to 1 December 1983 were randomized to receive TMP-SMZ plus colistin or neomycin plus colistin; and those admitted after 1 December 1983 were randomized to receive either ciprofloxacin alone or TMP-SMZ plus colistin. All agents were capable of preventing infections. However, the use of TMP-SMZ alone led to an increase in the number of infections caused by multiresistant microorganisms. The combination of TMP-SMZ plus colistin was superior to that of neomycin plus colistin. The new quinolone derivative ciprofloxacin was more effective than TMP-SMZ and was well tolerated. Antimicrobial prophylaxis with agents that provide adequate levels of drug in tissue prevents infections in granulocytopenic patients and is superior to that with nonabsorbable agents.

Agranulocytosis↗