Antiproliferative effect of mifepristone (RU486) on human neuroblastoma cells (SK-N-SH): in vitro and in vivo studies

RU486 (mifepristone), a glucocorticoid and progesterone receptor antagonist, has been reported to exert antiproliferative effects on tumor cells. Experiments were performed to analyze the effects of RU486 on the proliferation of the human neuroblastoma, both in vitro and in vivo, using the human neuroblastoma SK-N-SH cell line. The exposure in vitro of SK-N-SH cells to RU486 revealed a dose-dependent inhibition of ³H-thymidine incorporation due to a rapid but persistent inhibition of MAPKinase activity and ERK phosphorylation. A significant decrease of SK-N-SH cell number was evident after 3, 6, and 9 days of treatment (up to 40% inhibition), without evident cell death. The inhibitory effect exerted by RU486 was not reversed by the treatment of the cells with dexamethasone or progesterone. Moreover, RU486 induced a shift in SK-N-SH cell phenotypes, with an almost complete disappearance of the neuronal-like and a prevalence of the epithelial-like cell subtypes. Finally, the treatment with RU486 of nude mice carrying a SK-N-SH cell xenograft induced a strong inhibition (up to 80%) of tumor growth. These results indicated a clear effect of RU486 on the growth of SK-N-SH neuroblastoma cells that does not seem to be mediated through the classical steroid receptors. RU486 acted mainly on the more aggressive component of the SK-N-SH cell line and its effect in vivo was achieved at a concentration already used to inhibit oocyte implantation.

New insight on the molecular aspects of glucocorticoid effects in nervous system development

Adrenal glucocorticoids (Gc) are among the most significant hormones in the mammalian organisms; these steroids may reach and penetrate all tissues where they interact with cytoplasmic/nuclear receptors, through which they exert multiple and very multifaceted actions. The effects of physiological concentrations of Gc on brain functions have not been completely clarified, even though Gc are recognized to influence behavioral responses, emotions, cognitive processes and to take part in the neuroendocrine control of body homeostasis. Developmental programming effects of Gc in animal models and humans have been proposed. Actually, pre-natal stress, or exposure to high Gc levels, would somehow affect neuronal developmental events in some structure and this can lead to central nervous system altered functions, as the impairment of neuroendocrine activities, cognitive processes, sleep and mood disorders. Interestingly, it has been observed that these abnormalities may not be limited to the first directly exposed individuals but transmissible across generations. The establishment of animal models with localized pre-natal glucocorticoid receptors deficiency led to the accumulation of data on the possible roles of these hormones on development of the central and peripheral nervous system. The most recent findings on the effects of Gc on neuroblast development, with particular attention to neuronal migration, will be presented.

Kyphoplasty versus percutaneous vertebroplasty using the traditional and the new side-opening cannula for osteoporotic vertebral fracture

AIM

The aim of this article was to study the results of two different types of percutaneous vertebroplasty (PV) and kyphoplasty (KPs) to osteoporotic vertebral fractures (OVF).

METHODS

It was prospectively analyzed a series of 47 PVs from January 2003 to February 2008, and a consecutive series 30 KPs from March 2008 to January 2010, performed for patients with painful OVFs. Twenty-five PVs were performed using the frontal-opening cannula (FOC) and 22 using the new side-opening cannula (SOC), randomly distributed in the PV group.

RESULTS

The incidence of cement extrusion was 16.7% with KP, comparing with PV, it was 27.3% using the SOC (P<0.05) and 68,0% with the FOC (P<0.05), but comparing SOC with FOC, the cement extrusion was significantly lower using the SOC (P<0.05), all asymptomatic. The pain control was similar for all groups (P<0.05), with good improvement of pain in most of the patients, and there were no clinical relevant complications.

CONCLUSION

The cement leakage was significantly reduced with the KP (16.7%) and the SOC (27.3%) for PV, in comparison with the FOC (68.0%). The cement extrusion was slightly lower with KP, but not a significant difference, comparing with SOC, increasing the safety of the procedure using both the KP and this new SOC.

Effects of low-dose of niacin associated to simvastatin in the treatment of mixed dyslipidemia Salgad

AIM

The aim of this study was to evaluate the effects of low-dose niacin extended-release (niacin-ER) combined with simvastatin (SV) in the treatment of patients with mixed dyslipidemia who have not normalized their lipid profile with statin therapy alone.

METHODS

A prospective, clinical trial of 35 patients with mixed dyslipidemia who were treated with niacin-ER and SV. The dosage administrated were 250 mg niacin-ER plus 10 mg SV in the first two weeks, 500 mg/20 mg in the next two weeks, and 750 mg/20 mg in the final four weeks. Patients received 200 mg of acetylsalicylic acid 30 minutes before each drug administration.

RESULTS

There were significant increases of apolipoprotein A-I and HDL; and decrease of apolipoprotein B, LDL, triglycerides, and total cholesterol. There was low frequency of flushing (10%) and no worsening in the control of fasting and postprandial glycemia and glycated hemoglobin.

CONCLUSION

Low-dose niacin-ER associated to simvastatin may be useful for achieving improvement in lipid profile or even to achieve the targets recommended for prevention of cardiovascular disease. Other advantages are the low frequency of flushing, which improved adherence to treatment, and no worsening of insulin resistance in patients with or without diabetes mellitus.

Effects of metformin and short-term lifestyle modification on the improvement of male hypogonadism associated with metabolic syndrome

AIM

The metabolic syndrome is associated with male hypogonadism, but specific studies about the mechanisms and treatment of the testosterone deficit are scanty. The aim of this study was to evaluate the effects of metformin combined with diet and physical activity on the testicular function of men with metabolic syndrome.

METHODS

Thirty-five men (40.4 ± 13.3 years old) with metabolic syndrome were evaluated before and after a four-month period of therapy with metformin 850 mg twice daily, associated with a balanced normocaloric diet and subtle improvement in physical activity. The subjects were divided in two groups: 21 males with normal plasma testosterone levels (≥ 300 ng/dL) and 14 males with low plasma testosterone levels (< 300 ng/dL).

RESULTS

There was a significant decrease in fasting insulin levels and HOMA-IR after treatment (P = 0.01 and P = 0.06), which was more pronounced in the hypogonadic group (for the effect of absence or presence of hypogonadism, P = 0.04). The mean total and free testosterone levels increased significantly after treatment in both groups, similarly. The increase in FSH levels was more pronounced in the hypogonadic group than in the eugonadic group.

CONCLUSION

In this series of males with metabolic syndrome, treatment with metformin associated with healthy dietary modifications and a mild physical activity increment resulted in significant improvement of insulin sensitivity and increase in total and free testosterone levels, regardless of the presence of hypogonadism.

Internal carotid bifurcation aneurysm in childhood: a case report and literature review

Childhood aneurysms are rare pathological findings. They present with a low incidence and have characteristic features. When occurred in the first year of life or when giant-sized, survival and recovery may be worst. Nevertheless outcomes are generally better than in adults. A surgical case of an eleven year old boy with excellent outcome is reported, with a subsequent review on the subject. Patients may present with classical subarachnoidal hemorrhage, but also with compressive signs with bigger and unruptured lesions. Initial management of these cases is basically the same of older patients, considering their age, weight and special intensive care for infants. Surgical principles, outcomes and etiology are analyzed.

Patients with nephrolithiasis and blood hypertension have higher calciuria than those with isolated nephrolithiasis or hypertension?

AIM

The aim of this study was to determine urinary excretion of calcium, uric acid and sodium and to evaluate insulin resistance in patients with nephrolithiasis and blood hypertension, isolated and in association, and in healthy controls, in absence of obesity and diabetes.

METHODS

The study included 83 non-obese or diabetic patients: 17 with nephrolithiasis and hypertension (group D); 25 with nephrolithiasis (group C); 17 with hypertension (group B) and 24 healthy controls (group A). Urinary analysis was done in 24-hour urine collection and insulin resistance was evaluated through the HOMA-IR index.

RESULTS

Calciuria was higher in group D in relation to groups A (P<0.01), B (P<0.01) and C (P=0.01). There was no significant difference between groups A and B (P=0.32), A and C (P=0.10) and B and C (P=0.68). Correlation analysis between urinary calcium detected strong correlation with uric acid in group A, regular in groups B and C and, strong with sodium in groups B and C. No differences were detected in uric acid and sodium excretion or insulin resistance among groups.

CONCLUSIONS

Patients with blood hypertension and nephrolithiasis present higher calciuria than healthy people, with hypertension or with lithiasis and do not have the positive correlation observed in these latter groups with renal excretion of uric acid and sodium. These results suggest that impaired renal calcium reabsorption in non-obese or diabetic individuals is involved in the association between hypertension and urolithiasis.

Craniofacial abnormalities, obesity, and hormonal alterations have similar effects in magnitude on the development of nocturnal hypoxemia in patients with acromegaly

BACKGROUND

In patients with acromegaly, sleep apnea-related hypoxemia results in considerable morbidity and mortality.

AIMS

To evaluate the relative weight of pathogenic factors in predicting such hypoxemia.

METHODS

In this cross-sectional study, 34 acromegaly patients were submitted to clinical evaluation, nocturnal oximetry, and nasolaryngeal airway tomography. GH, IGF-I, and its upper limit normal value were measured. Nocturnal hypoxemia was defined as >5 episodes of desaturation/h of sleep. Craniofacial abnormalities were expressed using a linear parameter index (LPI). Nocturnal hypoxemia was predicted using logistic regression, including the variables markers of craniofacial abnormality, hormonal alteration, and obesity. Coefficients were standardized in order to determine their effect magnitudes relative to the outcome. The best model included the variables gender, age, LPI, body mass index (BMI), and IGFI upper limit normal value.

MAIN RESULTS

In the absence of the age and gender variables, the odds ratio for the LPI (1.60) was slightly higher than those found for BMI (1.49) and upper limit normal value (1.40). When the data were adjusted for age, the hormone upper limit normal value presented little alteration (1.49), although the decrease in the LPI was considerable (1.21), as was the increase in the BMI (2.18). The relative weight of the LPI was age-dependent. The gender variable did not alter the relevance of the others.

CONCLUSIONS

The effects that craniofacial aspect, obesity, and hormonal alterations have on nocturnal hypoxemia are of similar magnitude.

The role of non-invasive dynamic tests in the diagnosis of Cushing's syndrome

OBJECTIVE

To evaluate the role of non-invasive dynamic tests in the diagnosis and differential diagnosis of Cushing's syndrome (CS).

METHODS

We studied laboratory features of 74 patients with endogenous CS, subdivided as follows: 46 (62.1%) with Cushing's disease (CD), 21 (28.3%) with an adrenal tumor, and 7 (9.5%) with ectopic ACTH syndrome (EAS).

RESULTS

In 100% of cases of CS we found serum cortisol levels greater than 1.8 microg/dl after low-dose dexamethasone suppression tests (LDDST), as well as elevation of midnight serum or salivary cortisol. However, urinary free cortisol was normal in 11.5% of patients. ACTH levels were suppressed in patients with adrenal tumors, normal or high in CD and invariably increased in EAS. After the 8-mg overnight dexamethasone suppression test (HDDST), serum cortisol suppression >50% was observed in 79.5% of cases of CD and in 28.6% of subjects with EAS, whereas cortisol suppression >80% was only found in CD. After stimulation with CRH or desmopressin an ACTH rise > or =35% occurred in 86.5% of individuals with CD and 14.3% of those with EAS, whereas an ACTH rise > or =50 achieved 100% specificity. Moreover, the combination of serum cortisol suppression >50% after HDDST and an ACTH increase > or =35% after the administration of CRH or desmopressin only occurred in CD.

CONCLUSION

Our findings demonstrate that LDDST had 100% sensitivity for the diagnosis of CS and that HDDST and stimulation tests with CRH or desmopressin may be very useful for confirmation of CS etiology when analyzed together or when more stringent cut-offs are used.

Diagnosis and management of hyperprolactinemia: results of a Brazilian multicenter study with 1234 patients

OBJECTIVE

The aim of the study was to evaluate clinical and laboratorial features of 1234 patients with different etiologies of hyperprolactinemia, as well as the response of 388 patients with prolactinomas to dopamine agonists.

DESIGN, SETTING, AND PATIENTS

A total of 1234 hyperprolactinemic patients from 10 Brazilian endocrine centers were enrolled in this retrospective study.

MAIN OUTCOME MEASURE

PRL measurement, thyroid function tests, and screening for macroprolactin were conducted.

RESULTS

Patients were subdivided as follows: 56.2% had prolactinomas, 14.5% drug-induced hyperprolactinemia, 9.3% macroprolactinemia, 6.6% non-functioning pituitary adenomas, 6.3% primary hypothyroidism, 3.6% idiopathic hyperprolactinemia, and 3.2% acromegaly. Clinical manifestations were similar irrespective of the etiology of the hyperprolactinemia. The highest PRL levels were observed in patients with prolactinomas but there was a great overlap in PRL values between all groups. However, PRL>500 ng/ml allowed a clear distinction between prolactinomas and the other etiologies. Cabergoline (CAB) was more effective than bromocriptine (BCR) in normalizing PRL levels (81.9% vs 67.1%, p<0.0001) and in inducing significant tumor shrinkage and complete disappearance of tumor mass. Drug resistance was observed in 10% of patients treated with CAB and in 18.4% of those that used BCR (p=0.0006). Side-effects and intolerance were also more common in BCR treated patients.

CONCLUSION

Prolactinomas, drug induced hyperprolactinemia, and macroprolactinemia were the 3 most common causes of hyperprolactinemia. Although PRL levels could not reliably define the etiology of hyperprolactinemia, PRL values >500 ng/ml were exclusively seen in patients with prolactinomas. CAB was significantly more effective than BCR in terms of prolactin normalization, tumor shrinkage, and tolerability.

Clinical and laboratory features greatly overlap in patients with macroprolactinemia or monomeric hyperprolactinemia

AIM

The aim of this study was to evaluate the clinical and laboratory features of 64 patients with macroprolactinemia and to compare them to those of individuals with monomeric hyperprolactinemia.

METHODS

The study included 64 patients (54 women and 10 men) with macroprolactinemia and 96 patients (70 women and 26 men) with monomeric hyperprolactinemia (32 with prolactinomas).

RESULTS

Symptoms related to prolactin (PRL) excess were found in about 44% of individuals from the macroprolactinemia group and in 88.5% of patients with monomeric hyperprolactinemia (P<0.0001). However, the frequency of menstrual disturbances (oligomenorrhea or amenorrhea), galactorrhea and erectile dysfunction did not differ in both groups. In contrast, the association of galactorrhea and menstrual disturbances was significantly more prevalent in women with monomeric hyperprolactinemia. Although mean PRL levels were higher in patients with monomeric hyperprolactinemia (565.9+/-2726.4 vs 113.3+/-94.5 ng/mL, P<0.001), there was a great overlap between both groups. Among macroprolactinemic patients, pituitary magnetic resonance imaging revealed an image suggestive of a microadenoma in 7 (10.9%) and a macroadenoma in 1 (1.6%). Normalization of PRL levels during therapy with dopamine agonists was significantly more frequent in patients with monomeric hyperprolactinemia than in subjects with macroprolactinemia (78.6% vs 32%, P=0.0006).

CONCLUSION

Our data show that symptoms related to PRL excess are frequently found in subjects with macroprolactinemia. Moreover, no clinical or laboratory features could reliably differentiate macroprolactinemic patients from those with monomeric hyperprolactinemia. Therefore, the screening for macroprolactin should not be restricted to asymptomatic patients.

Dexamethasone blocks the migration of the human neuroblastoma cell line SK-N-SH

Glucocorticoids (Gc) influence the differentiation of neural crest-derived cells such as those composing sympathoadrenal tumors like pheochromocytomas, as well as neuroblastomas and gangliomas. In order to obtain further information on the effects of Gc on cells evolving from the neural crest, we have used the human neuroblastoma cell line SK-N-SH to analyze: 1) the presence and the binding characteristics of Gc receptors in these cells, 2) the effect of dexamethasone (Dex) on the migration of SK-N-SH cells, and 3) the effect of Dex on the organization of the cytoskeleton of SK-N-SH cells. We show that: 1) receptors that bind [(3)H]-Dex with high affinity and high capacity (Kd of 9.6 nM, Bmax of 47 fmol/mg cytosolic protein, corresponding to 28,303 sites/cell) are present in cytosolic preparations of SK-N-SH cells, and 2) treatment with Dex (in the range of 10 nM to 1 microM) has an inhibitory effect (from 100% to 74 and 43%, respectively) on the chemotaxis of SK-N-SH cells elicited by fetal bovine serum. This inhibition is completely reversed by the Gc receptor antagonist RU486 (1 microM), and 3) as demonstrated by fluorescent phalloidin-actin detection, the effect of Dex (100 nM) on SK-N-SH cell migration is accompanied by modifications of the cytoskeleton organization that appear with stress fibers. These modifications did not take place in the presence of 1 microM RU486. The present data demonstrate for the first time that Dex affects the migration of neuroblastoma cells as well as their cytoskeleton organization by interacting with specific receptors. These findings provide new insights on the mechanism(s) of action of Gc on cells originating in the neural crest.

Treatment for acute lymphoblastic leukemia in children is associated with papillary carcinoma of thyroid, but not with thyroid disfunction

AIM

The treatment of acute lymphoblastic leukemia (ALL) in children may cause sequelae, some appearing only at long-term follow-up. We investigated the thyroid gland morphology and the function of the pituitary-thyroid axis in a group of patients treated for ALL in childhood.

METHODS

A cohort study was conducted at a tertiary medical center. Thirty-three children (22 males and 11 females; age: 11.9+/-3 years; range: 6 to 18 years) were studied. The mean age at the time of chemotherapy and prophylactic cranial irradiation (12-24 Gy) was 5.5+/-2.6 years (range: 1 to 14 years). The average length of the follow-up was 6.1+/-3 years (range: 2 to 12 years). Thyroid morphology (n=33) was evaluated by palpation and ultrasonography. Thyroid function (n=30) was evaluated measuring total T3 and T4, and by the thyrotrophin-releasing hormone (TRH) test. Prolactin secretion was assessed before and after injection of TRH to evaluate the diagnostic test accuracy.

RESULTS

One out of the 33 children (3%) was found to have a papillary carcinoma of thyroid four years after ALL treatment. Thyroid function was normal in all the patients, however one case (3%) showed high TSH (9.2 microU/mL) and prolactin (37.5 ng/mL) basal levels, but normal responses to TRH (TSH = 17.8 microU/mL; prolactin = 82.3 ng/mL). These hormonal alteration were not confirmed at follow-up: TSH = 1.6 microU/mL and prolactin = 13.7 ng/mL.

CONCLUSIONS

In this cohort of patients, the treatment of ALL was associated with one case of thyroid carcinoma, but it did not produce adverse effect on the thyroid function, at least after a follow-up lasted on average 6 years.

Growth hormone provocation tests and their prediction in the growth of children treated for acute lymphoblastic leukemia

AIM

The aim of this study was to evaluate the positive predictive value of two growth hormone stimulation tests (insulin-induced hypoglycemia and clonidine) for stature below percentile 10 in patients treated for acute lymphoblastic leukemia in childhood.

METHODS

The study population was a cohort of 30 patients (aged 14.1+/-2.9 years; 20 male) treated for acute lymphoblastic leukemia during childhood and then examined after insulin-induced hypoglycemia (30 patients) and clonidine (16 patients) tests. The follow-up time was 7.7+/-2.8 years since treatment and 2.3+/-1.3 years after administration of the tests.

RESULTS

In the last evaluation, 12 patients (40%) were below and 18 (60%) were above percentile 10. The insulin-induced hypoglycemia test response was: 9 patients (30%) had growth hormone peak <5 ng/mL and 19 (63.3%) <7 ng/mL. The clonidine test response was: 7 patients had growth hormone peak <5 ng/mL and 8 (50%) <7 ng/mL. For stature below of the percentile 10, the positive predictive values of insulin-induced hypoglycemia test (33%) and clonidine (28%) were low when growth hormone peak <5 ng/mL was considered; however, when growth hormone peak <7 ng/mL was considered, the positive predictive values were 83% and 50% for the insulin-induced hypoglycemia and clonidine tests, respectively.

CONCLUSIONS

In patients treated for acute lymphoblastic leukemia in childhood, the positive predictive values for statural deficit of both tests were low, except for the insulin-induced hypoglycemia test when a growth hormone peak <7 ng/mL was considered.

Surgical treatment of bilateral multiple intracranial aneurysms. Review of a personal experience in 69 cases

AIM

There has been much controversy concerning the surgical treatment of bilateral multiple intracranial aneurysms. Some authors advocate the use of two-stage surgery by bilateral pterional craniotomies and others advocate the one stage complete repair of all lesions using the contralateral approach. We analyze the surgical experience of one neurosurgeon using both approaches.

METHODS

Sixty nine patients operated on for bilateral multiple intracranial aneurysms were divided in three groups: group A comprised 43 patients (62.3%) in whom all bilateral aneurysms were treated by one stage operation; group B comprised 9 patients (13.0%) in whom the clipping of the contralateral aneurysm it was not possible through the same approach, needing a second operation; group C comprised 17 patients (24.7%) in whom all bilateral multiple intracranial aneurysms were treated by two stage operations.

RESULTS

According to the Glasgow Outcome Scale 61 cases (88.4%) had excellent or good results (GOS V, IV), 2 cases (2.9%) had fair results (GOS III) and 6 patients have died (GOS I). The results of group A were significantly better than in-group B (p<0,05 Fisher test), but they were not different in relation to the group C (p=0,439 Fisher test). Among the six deaths, only one was related to the surgical procedure.

CONCLUSIONS

Under favorable clinical situations, as patients in H&H I to III, good brain conditions during the surgical procedure and aneurysms smaller than 1,5 cm, the contralateral surgical approach for the treatment of patients with bilateral multiple intracranial aneurysms can be used with advantages over the two stage approach.

Differential diagnosis and treatment of hyponatremia following pituitary surgery

Hyponatremia is a frequent occurrence after pituitary surgery, having been described in 9% to 35% of the patients. It is produced by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) or, more frequently, by the cerebral salt-wasting syndrome (CSWS). The clinical presentation of both syndromes is identical and the differential diagnosis can be difficult. The determination of the volemic state is essential for the diagnosis, since the patients with the SIADH are euvolemic or hypervolemic, while those with CSWS are hypovolemic. Several methods can be used to detect the volemic state in these patients and, among them, the furosemide test can best discriminate between SIADH and CSWS. A furosemide infusion (20 mg) normalizes sodium serum levels in SIADH patients, but not in CSWS patients who remain hyponatremic. The differentiation between the 2 syndromes is clinically relevant since their treatment is antithetical. SIADH patients need liquid restriction of liquids and/or furosemide to reduce the volume of extracellular water, while CSWS patients need volume replacement with sodium supplementation (or fludrocortisone can be a good alternative). The diagnosis and treatment of these syndromes are discussed on the basis of the literature reports.

Proteus syndrome and somatic mosaicism of the chromosome 16

The authors describe clinical pathologic findings in a patient with a structural chromosome 16 anomaly in mosaic distribution with the phenotypic characteristics of the Proteus syndrome. This is the 1st report showing that the Proteus syndrome may be associated with a chromosome 16 anomaly; while previous findings suggested that this syndrome was associated with a modification of chromosome 1. As the pathologic hypothesis of this syndrome possibly involves lethal genes in somatic mosaicism, responsible for control of cellular proliferation and/or alteration in the mechanism of action of some growth factors, chromosomal alterations found in the patient described in this work may suggest the location of the genes involved in this syndrome.

One-year follow-up of Graves' disease treatment by four different protocols of radioiodine administration

BACKGROUND

Studies have been performed in order to assess a treatment with 131I able to induce a consistent improvement in Graves' hyperthyroidism.

METHODS

EXPERIMENTAL DESIGN

For this purpose, four different protocols based on four different doses of radioiodine have been tested in Graves' disease patients. Patients never submitted previously to antithyroid drug treatment were given 1 mCi/10 gm of the estimated thyroid weight (group I; n = 50). Group II (n = 48) included patients not previously treated with antithyroid drugs and who were given doses of iodine based on a formula taking into account the rate of thyroid iodine uptake, i.e. 131I dose = microCi/gm of the estimated thyroid weight x 100/24 hrs 131I uptake (%). Patients previously submitted to antithyroid drug therapy were treated with radioiodine whose dose was calculated according to the formula reported above, but the dose was increased in order to overcome the possible resistance of this kind of patients to the effect of 131I. One group (group III; n = 24) received the calculated dose plus 1 microCi/gm of the estimated thyroid weight. Finally, group IV (n = 27) received the calculated dose plus 0.25 microCi/gm of the estimated thyroid weight.

RESULTS

The analysis of the patients one year later demonstrated that groups I and II presented the higher percent of euthyroid patients (60% and 58%, respectively) followed by group IV (37%) and group III (29.2%). The percent of patients still exhibiting hyperthyroidism was 28% in group I, 26% in group IV, 12.5% in group III and 8.3% in group II. The highest number of hypothyroid patients was present in group III (58.3%) followed by group IV (37%), group II (33.3%) and group I (12%).

CONCLUSIONS

The data here presented suggest that protocols I and II based on relatively low doses of radioiodine are rather effective in reducing Graves' hyperthyroidism in patients not submitted previously to antithyroid drug therapy. The most satisfactory therapy seems that utilized in protocol II, that in front of a fair amount of euthyroid patients (58.3%) presents a very low number of subjects still hyperthyroid (8.3%). However, the number of patients who became hypothyroid (33.3%) as a consequence of the therapy was too high. Hopefully, a better design of the protocol will reduce this figure. The high incidence of hyperthyroidism observed in groups III and IV submitted to a therapy with 131I doses consistently higher than those utilized in groups I and II seems to confirm the hypothesis that hyperthyroid subjects submitted to a therapy with antithyroid drugs become rather resistant to a radioiodine treatment.

Positive predictive values of selected clinical signs associated with skull base fractures

BACKGROUND

The goal of this study was to determinate the positive predictive values of selected clinical signs for skull base fractures and associated intracranial lesions.

METHODS

EXPERIMENTAL DESIGN

Clinical and radiological data were collected prospectively for all patients with selected clinical signs of skull base fractures, and their admission criteria were: 1) recent head injury story; 2) presence of one or more of following clinical signs: unilateral or bilateral blepharohaematoma, bloody otorrhea, and Battle's sign.

SETTING

Emergency service of a institutional hospital.

PATIENTS

One hundred forty two patients with the selected clinical signs for skull base fracture.

RESULTS

Frontal bone fractures were the most frequent in patients with selected clinical signs. Battle's sign (100%) and unilateral blepharohaematoma (90%) were the signs with higher positive predictive values for skull base fractures; bilateral blepharohaematoma (70%) and bloody otorrhea (70%) were those with less values. The positive predictive values of the selected signs for intracranial lesions (acute extradural haematoma, pneumocephalus, brain contusion, brain sweLling, and acute subdural haematoma) were: unilateral and bilateral blepharohaematoma with positive predictive values of 85% and 68%, respectively; Battle's sign was 66%; and bloody otorrhea was 46%. For patients at admission on the 13-15 Glasgow Coma Scale only, the positive predictive values for that intracranial lesions were: blepharohaematoma=78%; Battle's sign=66%; and bloody otorrhea=41%.

CONCLUSIONS

Our data demonstrated that the selected signs of skull base fractures have high positive predictive values for the presence of skull fracture and intracranial lesions, even in those patients classified in the Glasgow Coma Scale between 13 and 15. This indicates that all patients with the selected clinical signs should be submitted to computerized tomography of skull and with bone window, with the aim to detect associated lesions.

Factors released by rat type 1 astrocytes exert different effects on the proliferation of human neuroblastoma cells (SH-SY5Y) in vitro

Brain metastases derived from abdominal neuroblastoma are an uncommon complication of this tumour; however, an increase in their occurrence has recently been reported. In the present study, we have investigated the influence of factors derived from central nervous system glial cells on the proliferation of human neuroblastoma cells (SH-SY5Y) in vitro. Co-culture experiments show that a 24-h exposure to factors released by type 1 astrocytes (A1) may induce a significant decrease in [(3)H]thymidine ([(3)H]TdR) incorporation by SH-SY5Y cells. This effect was not duplicated by fresh A1-conditioned medium (A1-CM); A1-CM became active only when it was heated or frozen. In contrast to this short-lived inhibitory effect, long-term treatment (3, 6 and 9 days) with A1-CM produced a significant and dose-dependent increase in SH-SY5Y cell number. Immunoneutralisation of A1-CM with an anti-transforming growth factor-beta antibody eliminated the inhibitory effect on [(3)H]TdR uptake in SH-SY5Y cells, but did not affect the increased number of viable cells observed after long-term treatments. In conclusion, these results showed that factor(s) released by A1 may affect the proliferation/survival of a human neuroblastoma cell line in vitro inducing: (a) a short transient negative effect on DNA synthesis and (b) an overall sustained trophic action. These results are suggestive of a possible role of glial cells in the establishment of brain metastases of neuroblastomas.

Effects and metabolism of steroid hormones in human neuroblastoma cells

The development of the central nervous system is influenced by sex steroids and by their metabolites. However, little information on the possible effects of steroid hormones on neuroblastoma cells is available. Human neuroblastoma cell lines have been used as a model of human neuroblasts in vitro to study the metabolism of steroid hormones; in addition, the effects of steroids and steroid antagonists on neuroblastoma cell growth have also been investigated. The results obtained show that SH-SY5Y human neuroblastoma cells may actively metabolize testosterone and progesterone to their respective 5 alpha-reduced metabolites and that differentiation of neuroblastoma cells is paralleled by a significant increase in expression of the type-1 5 alpha-reductase and of the formation of steroid metabolites. All these data are suggestive of a potential role of steroid 5 alpha-reduced metabolites in the biology of neuroblastoma cells. Studies performed to analyze the role of steroid hormones on neuroblastoma cell proliferation show that progesterone at low doses may induce minor stimulation, and at higher doses, a toxic effect on the neuroblastoma cell line SK-N-SH is seen. Moreover, the antiprogestin 17 beta-hydroxy-11 beta-(4-dimethylamino-phenyl-1)-17-(prop-1-ynyl)estra-4,9-dien+ ++-3-one (RU486) decreases the proliferation of these cells in a dose-dependent manner. The effect of RU486 is not antagonized by either progesterone or dexamethasone, a result that seems to exclude the action of RU486 via classic intracellular steroid hormone receptors.

Antiprogestins inhibit the binding of opioids to mu-opioid receptors in nervous membrane preparations

The present study showed that the glucocorticoid/progesterone antagonists, 17 beta-hydroxy-1 1 beta-(4-dimethylamino-phenyl-1)-17-(prop-1-ynyl)estra-4,9-dien+ ++-3-one (RU486) and 17 beta-hydroxy-11 beta-(4-dimethylamino-phenyl-1)-17-(propan-3-ol)estra-4,9-dien-3-o ne (ZK 98299), inhibit the binding of labeled dihydromorphine to mu-opioid receptors present on membrane preparations derived from rat and mouse brain, as well as from human neuroblastoma cells. The inhibitory effect of RU486 was dose-dependent and linked to a decrease of the affinity of labeled dihydromorphine to the mu-opioid receptors. Kinetic experiments have shown that RU486 induces a decrease of the association rate constant (k + 1) of dihydromorphine. RU486 also proved able to dissociate the dihydromorphine-mu-opioid receptor complex, although at a rate slower than that exhibited by unlabeled dihydromorphine. Finally, the addition of NaCl (100 mM) to the incubation buffer induced a 50% decrease of the inhibitory effect of RU486. A 6-day treatment of neuroblastoma cells with RU486 eliminated the inhibitory effect morphine exerts on the intracellular accumulation of cyclic AMP induced by prostaglandin E1. These results indicate that RU-486 may interact with brain mu-opioid receptors in vitro, by decreasing the affinity of opioid ligands.

Effect of oestrus cyclicity on the number of brain opioid mu receptors in the rat

The present experiments have been performed in order to analyse whether the binding characteristics of brain opioid receptors of the mu type vary during the different phases of the oestrous cycle in the female rat. To this purpose different groups of females with a regular 4-day oestrous cycle were killed by decapitation in different phases of their oestrous cycle, i.e. at 10.00 and 16.00 h of the first and second day of dioestrus, at 10.00, 12.00, 14.00, 16.00 18.00 and 20.00 of the day of pro-oestrus, and at 10.00, 12.00 14.00, 16.00 and 18.00 of the day of oestrus. The total brains, after discarding the cerebellum, were homogenized and crude membrane preparations were obtained. On these preparations the maximal binding capacity (Bmax, index of the number of receptors) and the constant of affinity (Ka) for dihydromorphine, a typical ligand of mu opioid receptors were evaluated. Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were measured by specific radioimmunoassays in order to exactly ascertain the different phases of the oestrous cycle. The results obtained show that the number of mu opioid receptors in the whole brain presents significant changes during the different phases of the oestrous cycle. In particular, an increase in the concentration of these receptors was observed at 12.00 h of the day of pro-oestrus and at 18.00 h of the day of oestrus; these fluctuations of the number of mu receptors were not accompanied by any change of their affinity for the ligand.(ABSTRACT TRUNCATED AT 250 WORDS)