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Biomedical subjects

L D de Haan

Publications and source records attributed to L D de Haan.

6 recordsLinked to original sources
PubMed1988

Alterations in size, shape and osmotic behaviour of red cells after splenectomy: a study of their age dependence.

In whole blood from splenectomized subjects (n = 20), red cells showed a significant increase of mean surface area (MSA), mean cell volume (MCV), MSA/MCV-ratio and osmotic resistance, with the mean cell haemoglobin concentration (MCHC) being decreased. Studies on red cell populations of different cell age revealed that the increase of MSA affects younger and older cells, whereas the increase of MCV can mainly be ascribed to young cells with low density. The increased osmotic resistance is mainly determined by older cells due to a more favourable MSA/MCV-ratio. Shortly after splenectomy (n = 5) the MSA of younger and older cells increased, whereas the increase of MCV affected only young cells with a lowered density; moreover, the MSA/MCV-ratio increased in older cells in particular, resulting in a relatively greater increase of osmotic resistance. An impaired maturation of the reticulocyte may underlie the initial increase of MSA and MCV of young cells, but the present results contradict the current view that delayed maturation explains the changes in morphology and osmotic resistance of asplenic red cells.

Adult↗
PubMed1984

Anovulation presumably due to the gonadotrophin-resistant ovary syndrome.

The clinical syndrome of the resistant ovary is described in a 24-yr-old woman (XX genotype) with secondary amenorrhea and primary infertility. She presented an increased secretion of gonadotrophins with a decreased secretion of estrogens. In the ovarian tissue only primary ovarian follicles and a thickened tunica albuginea were found. The elevated serum gonadotrophins could be further increased by the administration of exogenous LHRH and incompletely suppressed by exogenous estrogens (50 micrograms ethynylestradiol daily). However, serum LH concentration started with a further rise (positive feedback?) during this estrogen administration. Results of treatment with Cyclocur and ethynylestradiol (100 micrograms daily) in higher dosages are presented. Following discontinuation of the estradiol therapy regular menses resumed, which became ovulatory. The patient became pregnant 23 months after stopping the estradiol therapy.

Adult↗
PubMedDate not supplied

Cisplatin-based chemotherapy in advanced adenoid cystic carcinoma of the head and neck.

Nineteen patients, nine men and 10 women, with advanced adenoid cystic carcinoma (ACC), were treated with cisplatin either alone or in combination with doxorubicin and bleomycin. Median age was 51 years (range: 32-73 years). Two groups of patients were distinguished: Group 1 (N = 10) received single-agent cisplatin (50-120 mg/m2 IV every 4 weeks) for locoregional recurrence (N = 4), pulmonary metastases (N = 5), or as neoadjuvant therapy (N = 1). Five patients failed previous chemotherapy. No objective responses were observed, five patients showed stabilization of their disease for a median duration of 20 months (range: 3-50 months). Group 2 (N = 9) received a combination of cisplatin (20 mg/m2 IV on days 1-5), doxorubicin (50 mg/m2 IV on day 1), and bleomycin (30 mg IV on days 1-5), every 3 weeks. A complete remission (CR) was seen in one patient, lasting for 2 years, a partial remission (PR) in two patients (duration: 6 months and 6 years) (33%), and a stable disease (SD) in five patients (median duration: 15 months; range 3-24 months). One patient showed progression from the start. The observed toxicity was acceptable: dose reduction was required in five patients for myelosuppression or impairment of renal function; vomiting grade III (WHO) was seen in 10 patients. The median progression-free survival was 36 months (range: 7-77 months). Median overall survival was 81 months (range: 14-216 months). The role of cisplatin in this disease remains questionable.

Adult↗