Search PubMed⌕ Search

Biomedical subjects

D Smeenk

Publications and source records attributed to D Smeenk.

At least 19 recordsLinked to original sources
PubMed1988

Multivariate analysis of survival in differentiated thyroid cancer: the prognostic significance of the age factor.

A retrospective analysis of tumour and patient characteristics was performed in 202 patients with papillary (n = 132) or follicular (n = 70) thyroid carcinoma, in order to identify prognostic factors related to survival. The following facts were found to be unfavourably related to survival: follicular histology, extrathyroidal growth of the primary tumour (stage pT4), regional lymph node involvement (stages pN1-3), presence of distant metastases at diagnosis (stage pM1), male sex (in papillary cancer) and old age (only death due to thyroid tumour was evaluated). For 190 patients sufficient material was available to permit extensive histopathological investigation. In patients with papillary cancer the presence of small anaplastic foci and/or greater than 25% solid structures (n = 18) was correlated with a reduced survival rate. Our study underlines the importance of distinguishing, histologically, between papillary and follicular cancer and in addition demonstrates the prognostic value of histological grade in papillary (but not follicular) carcinoma. We applied Cox's proportional hazard model to the survival data of these 190 patients and, after stage grouping, found that tumour stage (locoregional vs. advanced disease) was the most important prognostic factor. The second most important factor was the histological (sub)type (well differentiated papillary carcinoma vs. moderately differentiated papillary carcinoma and follicular carcinoma). Age at diagnosis and sex appeared to be of lesser importance. Therefore our study does not recommend the use of age as a guide for therapeutical decisions in differentiated thyroid cancer.

Adenocarcinoma↗
PubMed1985

Morphologic characteristics of benign and malignant adrenocortical tumors.

Differentiation between benign and malignant tumors of the adrenal cortex was studied by means of seven histologic parameters. Each separate criterion was significantly different in two groups, one consisting of patients without metastases within 10 years after operation and one of patients with metastatic tumors. Discrimination on the basis of single parameters in individual patients, however, was of little value. When a histologic index was calculated using the same parameters but after "weighing," a much better discrimination was obtained. The histologic index and, to a lesser degree, the mitotic activity seems to be related to the survival time of the patients with adrenal cortical carcinoma. The authors conclude that the calculation of a histologic index based on a summation of different parameters makes it possible to differentiate between malignant and benign adrenal cortical tumors. As single parameters, tumor weight and mitotic activity have the highest discriminating value.

Adrenal Cortex Neoplasms↗
PubMed1985

Resynchronization patterns for urinary rhythms in rats after light-dark shifts.

Diurnal urinary rhythms during a fixed 12:12 light-dark cycle were studied in male and female rats. After a control period of 9 days the light-dark cycle was shifted either +6 or -6 h by delaying or advancing the light period, respectively. Subsequently the resynchronization process was studied for 19-21 days. In both male and female rats an asymmetry effect was present: resynchronization was more rapid after a -6-h shift than after a +6-h shift. However, female rats exhibited a rate of resynchronization slower than male rats. During the process of resynchronization a state of transient internal dissociation was found for all urinary constituents. These results probably point to different control systems rather than to different circadian pacemakers. Further analysis of the role of sex steroid hormones is required in view of the sex variations reported.

Adaptation, Physiological↗
PubMed1984

The treatment of adrenocortical carcinoma with o,p'-DDD: prognostic implications of serum level monitoring.

Thirty-four patients with adrenocortical carcinoma were treated with o,p'-DDD. Twenty-eight patients presented with metastases at entry, and spillage of tumour cells occurred at surgery in 6 other patients. Eight patients had objective tumour regression, of whom 7 had serum levels over 14 micrograms/ml. The 3 patients with a lasting remission had levels of greater than 15, greater than 25, greater than 25 micrograms/ml respectively during prolonged periods. Increased survival times were found in the group of 14 patients with o,p'-DDD serum levels higher than 14 micrograms/ml when compared with patients not treated after discovery of metastases. In the patients with levels less than or equal to 10 micrograms/ml no therapeutic effect was seen. Levels of over 20 micrograms/ml are associated with symptoms of reversible neuromuscular toxicity. Monitoring of serum levels during treatment is mandatory. It is suggested that serum levels of about 25 micrograms/ml during longer periods may be curative.

Adrenal Cortex Neoplasms↗
PubMed1979

Investigation of bone and mineral metabolism in hyperthyroidism before and after treatment using calcitonin, 47Ca and balance studies.

Seventeen normocalcaemic patients with severe hyperthyroidism were examined before therapy was initiated; 9 were re-examined about 1 year later. Studies with 47Ca under balance conditions and with calcitonin demonstrated a high rate of bone resorption in untreated patients. As a result of the increased bone turnover, the reaction to 6 MRC units of porcine calcitonin iv was more marked in the untreated than in the treated patients or the control group. In contrast to the normal diurnal pattern for PO4, it was found that during fasting the plasma PO4 level increases in the morning in patients with hyperthyroidism. This increase which was not suppressed by the administered dose of calcitonin developed in spite of an elevated urinary PO4 excretion. After treatment, the serum Ca concentration as well as the urinary and faecal Ca excretion was decreased. The Ca balance improved; the rapidly-exchangeable Ca pool returned to normal. The slowly-exchangeable and the total Ca pools, however, remained enlarged. The rate of bone resorption normalized. The accretion rate on the other hand remained elevated. This is atributed to continued enhancement of bone formation to compensate for the previous loss of bony tissue.

Adult↗
PubMed1978

The eosinophilic fibrohistiocytic lesion of the bone marrow. A mastocellular lesion in bone disease.

Seven patients are described, six with severe osteoporosis and the seventh with osteogenesis imperfecta with moderate osteoporosis. The iliac bone marrow trephine biopsy specimens of all seven showed peculiar infiltrates consisting of elongated mast cells, eosinophils, plasma cells, and varying numbers of lymphocytes. Only one patient exhibited signs of allergy with urticaria pigmentosa; the other six patients had no abnormalities that could be related to a known mast cell disease. The lesions described here are the same as those described in five patients by Rywlin as "eosinophilic fibrohistiocytic lesion in the bone marrow". However, in our methacrylate sections the fibrohistiocytes are shown to be mast cells. Although a relationship with drug hypersensitivity is disputed, the presence of the mast cells and eosinophils suggests an allergic condition.

Adult↗
PubMed1977

Hypothyroidism in an area of endemic goiter and cretinism in Central Java, Indonesia.

In an area of severe endemic goiter in Central Java, Indonesia, clinical overt or mild hypothyroidism appeared to be present in 7 out of 20 cretins and also in 12 out of 94 non-cretinous subjects, all 5-20 years of age, living in the village of Sengi. Hypothyroidism was not found in a control group of 70 subjects of the same age living in Londjong just outside the edemia. In hypothyroid subjects the plasma PBI-concentration was 0.98+/-0.32 mug/100 ml (mean+/-SD) vs. 2.72+/-1.24 mug/100 ml in euthyroid subjects from Sengi and 4.86+/-0.80 mug/100 ml in controls from Londjong. Values for T3 were 56.3+/-3.17 ng/100 ml in hypothyroids, 140.5+/-38.5 ng/100 ml in euthyroids from Sengi and 121.6+/-27.4 ng/100 ml in controls. The TSH levels (geometric mean and range) in these 3 groups were, respectively, 210.1 (108.0-342), 15.6 (3.0-372) and 4.1 (0.8-7.0) muU/ml. The differences between the mean concentration of PBI, T3 and TSH in the hypothyroid and euthyroid groups were highly significant (P less than 0.001). These data strengthen the clinical diagnosis of hypothyroidism in cretins as well as in non-cretinous subjects. All hypothyroid subjects had a PBI less than 1.8 mug/100 ml and T3 less than 120 ng/100 ml and TSH greater than 100 muU/ml. In 8 hypothyroid subjects, restudied 18 months after iodized oil injection, hypothyroidism was either corrected or markedly improved. It therefore appears that iodine deficiency per se in postnatal life may lead to (juvenile) hypothyroidism, which can be corrected by iodine therapy. Our findings have implications for the definition and diagnosis of endemic cretinism. Not all hypothyroid subjects in an area of endemic iodine deficiency should be classified as cretins.

Adolescent↗