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Biomedical subjects

B Kristensen

Publications and source records attributed to B Kristensen.

At least 91 records · Page 5Linked to original sources

Amelioration of postmenopausal primary hyperparathyroidism during adjuvant tamoxifen for breast cancer.

The effects of adjuvant treatment with tamoxifen on bone metabolism in a postmenopausal woman with primary hyperparathyroidism is presented. A 69-year-old woman with increased serum ionized calcium, parathyroid hormone, and 1,25-(OH)2 vitamin D levels and a normal bone scan received tamoxifen 10 mg three times daily for 1 year. During treatment bone turnover decreased whereas parathyroid hormone increased further. After cessation of treatment the calcium metabolic variables returned to pretreatment levels. The antiestrogen tamoxifen seems to behave as an estrogen on bone metabolism in primary hyperparathyroidism.

Aged↗

Oestrogen receptor status of primary breast carcinomas and their metastases. Relation to pattern of spread and survival after recurrence.

Immunohistochemical antibody techniques for detection of oestrogen receptors (ER) were applied to formalin fixed, paraffin embedded sections from 62 primary breast cancers, the metastases of their original regional lymph nodes (29 cases), bone marrow carcinosis (43 cases) and liver metastases (20 cases). Forty per cent of the primary tumours and 31% of the regional lymph node metastases were ER positive; in contrast, less than 20% of liver and bone marrow metastases were ER positive. The ER status of regional lymph node metastases was concordant with that of the primary tumour in 90% of the cases. The concordance rate was 75% for liver metastases and 58% for bone metastases. Patients with ER positive primary tumours had recurrence significantly more often in bone; ER negative tumours recurred more often in the liver. The survival after recurrence (SAR) was significantly related to the ER status of the primary tumour and to that of the regional lymph node metastases. In contrast, the SAR was not associated with the ER status of bone marrow carcinosis or liver metastases. Cox analyses showed that age and ER status of the primary tumour were the most important independent prognostic factors compared to other clinical, therapeutic, pathoanatomical and biochemical features. The study supports the hypothesis that tumour cell clones with different ER content are selected and adapted to grow in various anatomical sites. Moreover, the ER status of the primary tumour seems to be more important for the prognosis than the ER status of bone and liver metastases.

Breast Neoplasms↗

Metastatic pattern in recurrent breast cancer. Special reference to intrathoracic recurrences.

The anatomical and temporal patterns of recurrence were studied in 401 patients with first recurrence of breast cancer. All patients underwent the same scheduled investigation program: history, physical examination, blood tests, bone scanning, bilateral iliac crest biopsy, radiologic bone survey, chest x-rays, and ultrasound scanning of the liver. The current article focuses on the diagnosis of intrathoracic (ITH) recurrence. Most patients recurred in a single site and 50% of the recurrences were diagnosed within the first 2 years from initial diagnosis. Chest x-ray revealed ITH recurrence in 27% (109 patients), and in 8% the lung, pleura, and/or mediastinum were the only signs of recurrence. Generally, the status of primary demographic, clinical, and pathoanatomical characteristics were not predictive as to the development of ITH recurrence, although patients with pleural recurrences often had centrally located primary tumors, locally advanced disease, and often received adjuvant radiotherapy. Clinical symptoms and signs of ITH recurrence were present in only one third of the patients, and the diagnostic specificity and sensitivity of serum lactate dehydrogenase were only 33% and 85%, respectively. Since ITH recurrences often are silent, and since recurrence in this site may have both prognostic and therapeutical implications, routine chest x-ray is indicated in all patients with first recurrence of breast cancer.

Breast Neoplasms↗

Joint report of the first international comparison test on swine lymphocyte alloantigens (SLA).

The first international comparison test on swine lymphocyte alloantigens (SLA) was held in Helsinki, Finland in July 1986. The results reported were based on a comparison of 157 alloantisera originating from six laboratories. The antisera were tested against a selected panel of 264 lymphocyte samples belonging to four laboratories. The most common breeds in Europe were chosen for this first comparison test (Landrace and Large White). Eighteen of the 31 previously known specificities were confirmed and a new nomenclature was established.

Animals↗

Stopped flow mass spectrometry: applications to the carbonic anhydrase reaction.

Membrane inlet mass spectrometry is combined with a stopped flow technique in order to allow the recording of moderately fast transients in concentrations of dissolved gases. The method was used for direct measurements of CO2 transients in the spontaneous and enzyme catalyzed hydrations of carbon dioxide. Rate constants and activation energies were determined.

Carbon Dioxide↗

Metronidazole inhibition of hydrogen production in vivo in drug-sensitive and resistant strains of Trichomonas vaginalis.

H2 production by the human protozoan parasite Trichomonas vaginalis was monitored continuously under a mobile gas phase using a membrane-inlet mass spectrometer. Simultaneous and continuous measurement of dissolved H2, O2 and CO2 indicated that H2 evolution was inhibited at levels of O2 (less than 0.25 microM) undetectable by the technique, whereas CO2 production was stimulated. Respiration was not stimulated by admitting H2 to the gas phase. Metronidazole inhibited both H2 and CO2 production. Values of K1 for inhibition of H2 formation in strain ATCC 30001 (metronidazole sensitive) of 0.16 mM and in strain 85 (metronidazole resistant) of 1.0 mM were obtained. These data suggest that metronidazole not only competes with protons as electron acceptor but that the drug itself or a product of reduction actively inhibits some hydrogenosomal enzyme or electron carrier involved in H2 production. Under these conditions metronidazole inhibition leads to irreversible loss of cell motility.

Carbon Dioxide↗

The swine histocompatibility system SLA: serological studies in the common Swiss and Danish swine breeds.

Alloantisera were produced in common Swiss and Danish swine breeds by immunization with leucocytes or skin-grafts. Out of the 126 antisera, 66 were chosen for further study based on titrations employing lymphocytes from unrelated pigs typed with French SLA antisera (Vaiman, Chardon & Renard, 1979). The 66 selected antisera and the French reagents defining 26 SLA specificities were used to type lymphocytes from 595 unrelated pigs of the common Swiss and Danish breeds. The reaction-patterns of the French, Swiss and Danish antisera were adequately correlated for the French SLA specificities Nos FJ 2, 3, 6, 7, 8, 9, 11, 14, 19, 20 and 24 and for the haplotypes FJ 15.1.18 and FJ 5.4. In addition, a cluster of correlated Danish and Swiss antisera characterized a new specificity, provisionally designated CPH 31. This specificity was frequent in the Danish Landrace pigs. Using the reagents identified in this report, the segregation of SLA markers was studied. Back-cross families demonstrated segregation of 15 distinct SLA haplotypes of which 14 are common in French Landrace or Large White. Differences were found in haplotype frequencies in both the Swiss and the Danish Landrace and Large White breeds.

Animals↗

Preliminary evidence of segregation distortion in the SLA system.

The segregation of 11 well-defined SLA haplotypes was investigated in 40 Land-race and 48 Large White Danish and Swiss litters. Among the 11 haplotypes, the segregation of one (SLA 20-8.2.11) deviated significantly from the expected 1:1 segregation ratio in back-cross families. Tests indicated that these families were homogeneous with respect to segregation distortion, although the distortion was more pronounced in litters sired by heterozygous Danish boars than by heterozygous Swiss boars and Danish and Swiss sows. The data presented do not allow any definite conclusion about the cause of the segregation distortion. The possibility of the distortion being caused either by a complex similar to the T/t-complex found in mouse and contemplated in man or directly by the SLA region is discussed.

Animals↗

Glycolysis and respiration in yeasts. The Pasteur effect studied by mass spectrometry.

Simultaneous and continuous measurements of changes in CO2 and O2 concentrations in glucose-metabolizing yeast suspensions by mass spectrometry enabled a study of the Pasteur effect (aerobic inhibition of glycolysis) in Saccharomyces uvarum and Schizosaccharomyces pombe. A different control mechanism operates in Candida utilis to give a damped oscillation after the anaerobic-aerobic transition. The apparent Km values for respiration of the three yeasts were in the range 1.3-1.8 microM-O2. The apparent Km values for O2 of the Pasteur effect were 5 and 13 microM for catabolite-repressed and derepressed S. uvarum respectively and 7 microM for Sch. pombe. These results are discussed with respect to currently accepted mechanisms for the control of glycolysis.

Candida↗