Characterisation of the human NMDA receptor subunit NR3A glycine binding site.

In this study, we characterise the binding site of the human N-methyl-d-aspartate (NMDA) receptor subunit NR3A. Saturation radioligand binding of the NMDA receptor agonists [(3)H]-glycine and [(3)H]-glutamate showed that only glycine binds to human NR3A (hNR3A) with high affinity (K(d)=535nM (277-793nM)). Eight amino acids, which correspond to amino acids that are critical for ligand binding to other NMDA receptor subunits, situated within the S1S2 predicted ligand binding domain of hNR3A were mutated, which resulted in complete or near complete loss of [(3)H]-glycine binding to hNR3A. The NMDA NR1 glycine site agonist d-serine and partial agonist HA-966 (3-amino-1-hydroxypyrrolid-2-one), similarly to glycine displaced [(3)H]-glycine monophasically, suggesting a single common binding site. However, neither the partial agonist d-cycloserine nor the antagonist 7-chlorokynurenic acid displaced [(3)H]-glycine. Using homology modelling, a model of the NR3A binding pocket was generated which we suggest can be used to identify candidate agonists and antagonists. Our data show that glycine is a ligand, and most probably the endogenous ligand, for native NR3A at a binding site with unique pharmacological characteristics.

Positive effect of radiotherapy and surgery on hormonally active pulmonary metastases of primary parathyroid carcinoma.

OBJECTIVE: Parathyroid carcinoma is a rare cause of primary hyperparathyroidism. Surgery is the primary treatment in recurrent or metastatic disease. Radiotherapy has been used as an adjuvant to control subclinical local disease but is otherwise considered ineffective. DESIGN: We report on a patient with parathyroid carcinoma with hypercalcaemia and pulmonary metastases, treated with pamidronate and radiotherapy and later with surgery. METHODS: The treatment was evaluated using serial analysis of serum parathyroid hormone (PTH) and calcium, clinical evaluation and chest radiographs. RESULTS: Intravenous pamidronate alone had limited effect on hypercalcaemia. Following irradiation of the pulmonary lesions (34 Gy in ten fractions), serum levels of calcium and PTH decreased and pamidronate could be discontinued. The patient's general condition improved parallel to a radiological response. At clinical relapse 18 months following radiotherapy, the pulmonary metastases were resected and serum PTH was normalised. CONCLUSIONS: The results indicate that parathyroid carcinoma can be radiosensitive. Thus radiotherapy may be an alternative to palliate symptoms of hypercalcaemia in patients not suited for surgery.

Clinical and histopathological features of a large parapharyngeal neurilemmoma located at the base of the tongue.

Neurilemmomas of the tongue have only been sporadically reported in the literature. Vague symptoms and limited knowledge of this kind of tumor may result in long delays before diagnosis and treatment. The rarity of the lesion in this area is the main reason why we report this case of neurilemmoma. After observation of a mass in the tongue, magnetic resonance imaging showed a large tumor with central necrosis localized to the base of the tongue. Needle electromyography disclosed no nerve lesion. Fine-needle aspiration cytology was negative, whereas biopsy revealed a neurilemmoma. The tumor was surgically removed, and histopathology, including immunohistochemistry, of the resected specimen disclosed the typical neurilemmoma. The postoperative course was uneventful.

A novel spontaneous metastasis model of human osteosarcoma developed using orthotopic transplantation of intact tumor tissue into tibia of nude mice.

Evaluation of potential new treatment strategies requires adequate experimental tumor models which resemble the clinical situation as closely as possible. The purpose of the present study was to establish a new human osteosarcoma spontaneous metastasis model using orthotopic transplantation of histologically intact tumor tissue into the tibia of nude mice. Intact tumor pieces, obtained from the 32nd serial passage of subcutaneously growing human osteosarcoma xenografts, were implanted into the proximal tibia in 31 nude mice. Animals were sacrificed and autopsied 2, 4, 6, and 8 weeks after transplantation and examined macroscopically and microscopically for local tumor growth and metastases. All mice developed local intratibial bone tumors that were radiographically and histologically similar to primary human osteosarcoma. Lung metastases were observed in all mice, local and distant lymph node metastases in 15 (48%), and liver metastases in 6 (19%) mice. The microscopic appearance of the metastases was similar to that observed in the donor patient's tumor, corresponding subcutaneous xenografts and orthotopically transplanted intratibial tumors. This spontaneous metastasis model of human osteosarcoma in nude mice may resemble a clinical situation and could thus be useful for studies on local tumor growth, metastasis formation and therapy.

Limited Wegener's granulomatosis with central nervous system involvement and fatal outcome.

A 74-year-old woman was admitted to the medical department with vertigo and confusion, and suffered seizures three days later. Clinical, radiological and histopathological examination revealed limited Wegener's granulomatosis (WG) with central nervous system (CNS) involvement. Initially she was treated successfully with prednisolone and cyclophosphamide, but she relapsed after 25 months and died four weeks later. Autopsy showed widespread granulomas with vasculitis in the cerebrum. These findings emphasize the importance of considering WG in CNS disease of unclear origin, and demonstrate the aggressive nature of the disease.

Structure, growth and cell proliferation of human osteosarcoma and malignant fibrous histiocytoma xenografts in serial transplantation in nude mice.

Tumour specimens from one patient with osteosarcoma and one with malignant fibrous histiocytoma were transplanted in serial passages in nude mice. Structure, growth and cell kinetics of the xenografts were studied in order to assess the validity of the two tumour models. Cell proliferation was analysed using in vivo labelling with the thymidine analogue iododeoxyuridine (IdUrd) and the IdUrd labelling index (LI) was determined by immunohistochemistry. The DNA index (DI) was examined by flow cytometry. The c-myc oncoprotein expression was studied by immunohistochemistry. More intense proliferation was observed in the peripheral parts of the tumours. There was no correlation between tumour growth and cell proliferation in the two tumour groups. Stability of the tumour models was indicated by low intrapassage and interpassage variations of DI, LI, and volume doubling time, and also by retained histopathological characteristics and c-myc staining patterns of donor patients' tumours during serial transplantation.

Growth patterns and cell kinetics of human osteosarcoma xenografts in serial passages in nude mice analyzed by in vivo labelling with iododeoxyuridine.

A human osteoblastic osteosarcoma was transplanted in nude mice and followed in seven serial passages. Tumor cell kinetics was analyzed by in vivo labelling with the thymidine analogue iododeoxyuridine (IdUrd). Immunohistochemistry was used to measure the IdUrd labelling index. Duration of S phase (ts) was estimated by flow cytometry. From these two parameters potential doubling time (tpot) was calculated. Cell kinetic parameters showed low variations between passages and also between xenografts in same passage. Smaller variations of ts compared to labelling index and tpot were found. tpot was generally short with an interpassageal mean of 1.3 days and CV=14.8%. All xenografts showed DNA aneuploidy (mean DNA index --1.6). Homogeneous tumor growth was indicated by low variations of volume doubling time and lag time. There was no correlation between tumor growth and cell proliferation. Histopathological characteristics of the donor patients tumor were retained during serial transplantation.

A one-year multicenter study of efficacy and safety of a continuous, low-dose, estradiol-releasing vaginal ring (Estring) in postmenopausal women with symptoms and signs of urogenital aging.

OBJECTIVE: We studied the efficacy, safety, and acceptability of an estradiol-releasing (6.5 to 9.5 micrograms per 24 hours) silicone vaginal ring (Estring) in postmenopausal women with symptoms and signs of urogenital aging during a treatment period of 1 year. STUDY DESIGN: The study was open with blind analysis of vaginal cytologic testing. In addition to gynecologic examination, subjective symptoms were assessed and vaginal pH and urinary samples (for bacteriuria) were obtained before insertion of Estring. This procedure was repeated every 3 months up to 1 year's treatment, together with requests concerning acceptability and adverse experiences. At inclusion and end of Estring treatment, vaginal smears for evaluation of cytologic results were obtained. RESULTS: Estring induced a high maturation value in the vaginal mucosa and restored vaginal pH to levels normality seen in fertile women (< 5.5). For most variables a 90% responder rate (proportion of cured and improved patients) was found after 3 months and up to 1 year regarding subjective symptoms and objective signs of vaginal mucosal atrophy. Twenty-eight (20%) of 136 women, withdrew from the study, 8 (6%) of them because of adverse events. Three women reported vaginal bleeding, none associated with malignancy or endometrial proliferation. Ten (7%) reported vaginal irritation, and in two cases vaginal ulcers were found. About 90% did not remove the ring during any of the 3-month treatment periods, and 78% used the four consecutive rings continuously up to 1 year. The ring was given a strong preference (p < 0.001) by patients with previous experience of other administration forms. CONCLUSION: Estring represents a safe, highly effective, and very well-accepted administration form for long-term treatment of urogenital disorders caused by estrogen deficiency in postmenopausal women.

Accuracy of clinical staging in non-seminomatous testicular cancer--a single centre experience of retroperitoneal lymph node dissection.

The management of low stage non-seminomatous testicular cancer remains a controversial issue. Programs of surveillance or primary retroperitoneal lymph node dissection (RPLND) after orchiectomy show equally good survival rates. Current focus is therefore on reduction of toxicity or side effects of the treatment while maintaining maximal prognostic safety. The clinician's decision of therapy is based on clinical staging methods including computerized tomography, pulmonary x-rays and serum tumour marker levels. In this study, the accuracy of clinical staging was compared with histopathology in 64 patients with clinical stages (CS) I and IIa, operated upon with RPLND between 1980 and 1992. Lymph node metastases were histopathologically verified in 37% of CS I and in 47% of CS IIa tumours. Thus, the clinical staging was inaccurate in 37% in CS I and in 53% in CS IIa patients. No clear relationship was shown between the risk factors: vascular invasion and/or tumour marker levels and metastatic spread. The specificity of clinical staging in non seminomatous testicular cancer was low. RPLND, on the other hand, is a reliable method for assessment of metastatic spread and will minimise unnecessary use of chemotherapy. Modern techniques for lymphadenectomy have a very low rate of post-operative morbidity. Development of better non-invasive imaging techniques for detection of lymph node metastases is hoped for, in order to improve the information on tumour spread and make it possible to individualize therapy. Thus, unnecessary therapy and following side-effects can be avoided, improving the patient's quality of life during and after treatment.

Thyroid cancer: reproductive factors, previous diseases, drug intake, family history and diet. A case-control study.

An association between female sex hormones and thyroid cancer has been suggested, but the only well-established risk factor is ionizing radiation. This case-control study was designed to evaluate the association between different aetiological factors and thyroid cancer and encompassed 180 cases aged 20-70 years at the time of diagnosis in 1980-89, and 360 controls. The response rate was 92%. A history of one pregnancy gave increased risk for papillary thyroid cancer, odds ratio (OR) = 3.1, 95% confidence interval (CI) = 1.0-11, whereas no increased risk was found for > or = four pregnancies. Age > or = 25 years at the time of the first pregnancy showed a non-significantly increased risk for papillary thyroid cancer, OR = 1.5, 95% CI = 0.8-3.0. Use of oral contraceptives before the age of 20 years gave an OR of 0.5, 95% CI = 0.1-1.3. A history of asthma or allergy, or the use of cortisone, significantly decreased the risk, while cardiovascular disease in men increased the risk of developing thyroid cancer. In the logistic regression, use of cortisone decreased the risk, while one pregnancy gave a significantly increased risk in papillary thyroid cancer. The results indicated that endogenous hormones may play a role in the aetiology of thyroid cancer in women.

A comparative multicenter study of the effects of continuous low-dose estradiol released from a new vaginal ring versus estriol vaginal pessaries in postmenopausal women with symptoms and signs of urogenital atrophy.

OBJECTIVE: Our purpose was to study the efficacy, safety, and acceptability of a new estradiol-releasing (6.5 to 9.5 micrograms per 24 hours) silicone rubber vaginal ring compared with Ovesterin 0.5 mg estriol vaginal pessaries. STUDY DESIGN: Gynecologic clinical status, vaginal pH, cytologic characteristics, and occurrence of bacteriuria were determined before starting and after 3 and 12 weeks of treatment in 146 postmenopausal women. RESULTS: Both treatments alleviated the subjective and objective symptoms of estrogen deficiency excellently, and both were equally effective at restoring the vaginal pH to levels normally seen in fertile women (< 5.5). Vaginal cytologic studies showed a significant difference in maturation value in favor of the estradiol-releasing silicone rubber vaginal ring, as measured by the pathologist's assessment of the proliferation of the vaginal mucosa. A total of 77% of users were classified as responders, compared with 39% in the pessary group. Both treatments were well accepted. The administration of the pessary was associated with a significantly higher (p < 0.001) incidence of discomfort than that of the ring, which was given better (p < 0.001) rating by the patients at the 12-week visit. A strong preference (p < 0.001) for the ring was shown by patients with previous experience with pessaries. CONCLUSION: Treatment of urogenital symptoms in postmenopausal women with an estradiol-releasing vaginal ring is shown to be an effective and safe method, exhibiting advantages over treatment with estriol vaginal pessaries.

Medical diagnostic and therapeutic ionizing radiation and the risk for thyroid cancer: a case-control study.

The aim of this study was to investigate exposure to diagnostic and therapeutic ionizing radiation as a risk factor for thyroid cancer. This case-control study encompassed 180 women and men with thyroid cancer, aged 20-70 years at the time of diagnoses in 1980-89. From the National Population Registry 360 controls were selected. The response rate was 95% for the cases and 90% for the controls. Thyroid radiation dose from medical and dental X-ray examinations was divided into three categories. The highest exposure category (> 0.59 mGy) yielded an odds ratio (OR) for women < or = 50 years of age of 2.7 with 95% confidence interval (CI) of 1.2-6.6. OR increased to 4.9 (CI = 1.6-16) if papillary cancer alone was considered in this age group. For women aged > 50 years and for men no significantly increased risks were seen. External radiotherapy yielded OR = 3.1 (CI = 0.9-12) and for women only OR = 4.9 (CI = 1.1-24). In papillary thyroid cancer, logistic regression gave increased risk for X-ray examinations with a thyroid dose > 0.59 mGy (OR = 2.7, CI = 1.0-6.9) and for external radiotherapy (OR = 2.7, CI = 0.4-16). No increased risk was found for exposure to 131I. The findings in this study indicated an association between diagnostic or therapeutic radiation and thyroid cancer in women, but may have been influenced by recall bias.

Occupational exposures and thyroid cancer: results of a case-control study.

A case-control study on thyroid cancer concerning 180 cases and 360 controls aged 20-70 years at diagnosis was performed. Both females and males were included. Of the cases, 63% had had papillary thyroid cancer. Work with diagnostic X-ray investigations constituted a risk factor for thyroid cancer of the papillary type yielding an odds ratio (OR) of 2.9 with 95% confidence interval (CI) = 1.1-8.3. For women only OR was 3.3 (CI = 1.2-9.8). The results also indicated that work as a lineman, which entails exposure to electromagnetic fields and chemicals, increased the risk. Exposure to impregnating agents gave an increased OR = 2.8 with CI = 1.0-8.6. For men only OR was 3.8 with CI = 1.1-16. Women who were previously smokers and female current smokers had significantly decreased risks with OR = 0.5 (CI = 0.2-0.96) and OR = 0.6 (CI = 0.3-0.96), respectively.

Instability and femoral head vitality in fractures of the femoral neck.

Sixteen patients with femoral neck fractures were studied with roentgen-stereophotogrammetric analysis (RSA) and low-field magnetic resonance (MR) imaging in addition to plain roentgenography. In six patients, these results were compared with the results of histopathologic analyses. All fractures were stabilized with two cannulated titanium screws. Evaluation of fracture movement before weight bearing (nine fractures) revealed no or only slight movement (less than 3.4 mm or 4.7 degrees). During weight bearing, two undisplaced fractures were compressed about 5 mm and one 20.3 mm, because of delayed union, which was verified by repeated RSA measurements and MR imaging. The average compression in nine displaced fractures that subsequently healed was 13.3 mm. MR imaging revealed signs of femoral head necrosis in three healed and two unhealed fractures. Segmental or total femoral head necrosis was histologically confirmed in all removed femoral heads, and the fracture areas were shown to be bridged by bone trabeculae to a varying degree. Absence of micromovement six months after fracture implied uncomplicated healing. Fracture stabilization at nine to 12 months postfracture was associated with femoral head necrosis or delayed union in four of six cases. Micromotion after more than one year indicated femoral head necrosis or pseudarthrosis.

Nucleolar organizer regions in uterine sarcomas.

Nucleolar organizer regions demonstrable by silver staining technique (AgNORs) are loops of nucleolar DNA transcribing to ribosomal RNA. This report quantifies AgNORs in normal endometrium and myometrium, and in leiomyomas and homologous sarcomas of the uterus. The mean AgNOR number in leiomyosarcomas was significantly higher than that in normal myometrium and that in leiomyomas, whereas no significant difference was observed between normal myometrium and leiomyomas. The mean AgNOR count in low-grade endometrial stromal sarcomas was significantly higher than that in normal endometrial stroma, and significantly lower than that in the high-grade variant of the same tumour. The epithelial component of malignant mixed müllerian tumours exhibited a significantly higher mean AgNOR number than normal endometrial epithelium, and the stromal component of these tumours showed a significantly higher mean AgNOR count than normal endometrial stroma and normal myometrium, respectively. The AgNOR count was significantly correlated with the mitotic rate in leiomyosarcomas, in high-grade endometrial stromal sarcomas, and in the epithelial and mesenchymal portions of mixed müllerian tumours, whereas no statistically significant correlation was observed in low-grade endometrial stromal sarcomas. Increased AgNOR counts have been reported for some kinds of malignant tumours in various organs, compared with normal tissues and benign tumours. This study demonstrates a similar increase when homologous uterine sarcomas are compared with histogenetically related normal and neoplastic tissues. AgNOR counting might be a useful adjunct in the classification and grading of uterine tumours.

Chronic achilles paratenonitis with tendinosis: an experimental model in the rabbit.

An experimental model for inducing chronic Achilles paratenonitis with tendinosis in the rabbit is presented. Thirteen rabbits were exercised in a kicking machine producing passive flexions and extensions of the ankle joint. Active contractions of the triceps surae muscles were induced by electric stimulation via surface electrodes. The animals were exercised for 5 to 6 weeks, with a rate of 150 flexions and extensions per minute for 2 h, three times a week. Light microscopic examination showed degenerative changes of the tendon, and increased number of capillaries, infiltrates of inflammatory cells, edema, and fibrosis in the paratenon. We conclude that chronic Achilles paratenonitis with tendinosis can be experimentally induced in a standardized manner in rabbits.

Kinetics of proteoglycans and cells in growth plate of normal, diabetic, and malnourished rats.

The metabolism of proteoglycans in normal growth plate and the changes in growth plate morphology induced by diabetes and malnutrition were studied in rats. The proteoglycans had a significantly faster turnover (half-life measured with [35S]sulfate labeling: 25-30 h) than the cells in the growth plate. Morphometric studies showed significant reductions of cell number, zone height, and [3H]thymidine incorporation in growth plates from rats with untreated streptozotocin-induced diabetes compared to normal rats. Similar, although less pronounced alterations were observed in malnourished, nondiabetic rats. Disaggregation and degradation of proteoglycans are probably necessary prerequisites for calcification. Our data indicate that the proteoglycans are in a dynamic state of rapid biosynthesis and degradation throughout the growth plate with a shift in the balance at the calcification front toward less synthesis and more degradation.

Nucleolar organizer regions in normal, hyperplastic and neoplastic parathyroid glands.

Using a one-stage silver staining technique, nucleolar organizer regions (AgNORs) were studied in paraffin sections of parathyroid glands (and in two lymph node metastases) from patients operated upon because of hyperparathyroidism or thyroid disease. The parathyroids were microscopically differentiated into normal, hyperplastic, adenomatous and carcinomatous glands. AgNORs were observed as distinct black dots of varying size and somewhat varying configuration in the nuclei of all glands. The mean number of AgNORs in the hyperplastic and adenomatous glands was not significantly different from that in the normal glands, whereas the carcinomatous glands exhibited significantly increased mean AgNOR number. No evidence was obtained for a role of AgNOR counting in the differentiation between normal and hyperplastic or adenomatous parathyroids, but the results suggest a potential role of enumeration of AgNORs in the discrimination between benign and malignant parathyroid neoplasms.

Inhibition by acetylsalicylate of the hyperglycemic response induced in mice by sodium nitroprusside.

The injection of sodium nitroprusside (SNP) into mice induced a hyperglycemic response which was reduced by pretreatment with acetylsalicylate (ASA). The activity of glutamate dehydrogenase was significantly increased in islets from pancreases removed after SNP injection. This effect was prevented by pretreatment with ASA. Isolated mouse islets incubated with SNP exhibited stimulated activity of glutamate dehydrogenase both in the presence of low and high glucose concentrations, whereas the release of insulin was stimulated at low but inhibited at high glucose concentrations. These changes were abolished in the additional presence of ASA. The findings indicate that the hyperglycemic action of SNP may be related to changes in the generation of cyclooxygenase products.

Effects of sodium nitroprusside on blood glucose concentration, B-cell morphology and islet glutamate dehydrogenase activity in mice.

Mice injected with sodium nitroprusside (NaNP) exhibited a marked, transient hyperglycemia and enhanced activity of glutamate dehydrogenase in the pancreatic islets. Ultrastructurally, the islet B-cells of NaNP-treated mice showed expanded granular endoplasmic reticulum, prominent Golgi complex, increased amount of secretory granules, mitochondrial enlargement and vacuolation, and mitochondrion-secretory granule complexes. Stereological analyses disclosed increased volume of endoplasmic reticulum, Golgi complex and mitochondria, and increased number of secretory granules in the B-cells 1 h after the injection of NaNP. Isolated mouse islets exposed to NaNP showed stimulated activity of glutamate dehydrogenase both in the presence of 2 and 18 mM glucose, whereas the release of insulin was stimulated at 2 mM glucose, but inhibited at 18 mM glucose. The observations demonstrate that NaNP induces transiently altered structure and function in mouse islet B-cells.