A simple ultrasound score for the identification of candidates to fine needle aspiration of thyroid nodules.

BACKGROUND: Cytological examination of fine needle aspirates (FNA) is the standard procedure for discriminating potentially malignant thyroid nodules to be referred to surgery. In a fraction of cases, ultrasound (US) examination could provide information theoretically sufficient to avoid FNA, when typical US features suggesting malignancies are lacking. AIM: The aim of this study was to construct a simple US score predicting malignant nodules so as to reduce the number of unnecessary FNA. SUBJECTS AND METHODS: In a series of 1632 consecutive patients undergoing US-guided FNA (1812 nodules), echostructure, echogenicity, margins, halo, microcalcification, and vascularization were assessed. RESULTS: At multivariate analysis, the following parameters showed a strong predictive value for positive cytology (Thy 4 and Thy 5, suspicious and diagnostic for malignancy, respectively, according to the Thyroid British Association): solid echostructure, irregular margins and hypoechogenicity [adjusted odd ratio (OR) 5.13 (1.58-16.66), 3.03 (1.70-5.39), 2.05 (1.17-3.57), respectively]. A 10-point Thyroid Risk Ultrasound Score (TRUS) was constructed on the basis of the adjusted OR. A TRUS≥6 identified malignant nodules with sensitivity and specificity of 73% and 65%, respectively. Among the patients with follicular lesions (Thy 3) and final diagnosis of carcinoma, about 65% had a TRUS≥6.0. CONCLUSIONS: The sensitivity of TRUS, although higher than that of other scores, could still be insufficient for the identification of patients who could avoid FNA in routine clinical practice, whereas its predictive value for Thy 3 lesions deserves further investigations.

Serum Th1 (CXCL10) and Th2 (CCL2) chemokine levels in children with newly diagnosed Type 1 diabetes: a longitudinal study.

AIMS: Cell-mediated immunity and pro-inflammatory cytokines are implicated in the pathogenesis of Type 1 diabetes. The aim of this study was to investigate whether circulating chemokines involved in T-helper 1 (CXCL10) and T-helper 2 (CCL2) autoimmunity are increased in children with Type 1 diabetes at onset and follow-up. METHODS: Serum CXCL10 and CCL2 were measured in 96 children with newly diagnosed Type 1 diabetes, 59 age-matched first-degree relatives of diabetic children and 40 age-matched non-diabetic children with no family history of diabetes. In the diabetic children, an additional serum sample was obtained a median of 16 months after diagnosis. RESULTS: Serum CXCL10 levels were significantly higher in Type 1 children than in relatives or control children (P < 0.001); 44.7% of patients had a serum CXCL10 level >or= 2 standard deviation above the mean value of the control group vs. 3.4% of relatives (P < 0.0001). In contrast, serum CCL2 levels were similar in patients, relatives and control subjects. In the Type 1 diabetic patients at follow-up, CXCL10 was significantly reduced vs. baseline (P = 0.01), while CCL2 did not change. CONCLUSIONS: In children with newly diagnosed Type 1 diabetes, raised serum CXCL10 and normal CCL2 concentrations signal a predominant T-helper 1-driven autoimmune process, which shifts toward T-helper 2 immunity over the first 1-2 years from diagnosis.

Human anti-CD38 autoantibodies raise intracellular calcium and stimulate insulin release in human pancreatic islets.

CD38 is involved in transmembrane signaling in many cell types; anti-CD38 autoantibodies have been described in diabetic patients. We tested whether human anti-CD38 antibodies possess signaling properties by measuring their ability to raise intracellular calcium ([Ca2+]i) using the fluo-3-acetoxymethyl ester method in a human-derived T-cell line (Jurkat T-cells, expressing high levels of surface CD38) and in dispersed human islet cells from normal donors. In Jurkat T-cells, 11 of 19 anti-CD38-positive sera raised [Ca2+]i (by > or =20% of baseline), whereas no [Ca2+]i-mobilizing activity was found in 27 anti-CD38-negative sera (chi2 = 20.5, P < 0.0001). In dispersed human islet cells, 5 of 11 anti-CD38-positive sera (and none of three anti-CD38-negative sera) raised [Ca2+]i significantly. When preincubated with Staphylococcus aureus protein A to remove IgG, anti-CD38-positive sera showed a 70 +/- 5% reduction in [Ca2+]i-mobilizing activity. Preincubation with CD38-transfected NIH-3T3 fibroblasts, but not with mock-transfected NIH-3T3 cells, abolished [Ca2+]i mobilization. In blocking experiments, preincubation with nonagonistic anti-CD38 monoclonal antibodies also prevented [Ca2+]i mobilization. In cultured human islets, anti-CD38-positive sera exhibiting [Ca2+]i-mobilizing activity in Jurkat T-cells (n = 6) significantly stimulated insulin release at 3.3 mmol/l glucose (median [interquartile range] 738 microU/ml [234], P = 0.0001 vs. 320 [52] microU/ml of control), whereas 6 anti-CD38-positive sera without [Ca2+]i-mobilizing activity and 10 anti-CD38-negative did not. In further incubations, the five anti-CD38-positive sera displaying [Ca2+]i-mobilizing activity in dispersed islet cells significantly stimulated insulin release at both 3.3 mmol/l glucose (2.2 +/- 0.3% of insulin islet content, P < 0.002 vs. 1.2 +/- 0.1% of control) and 16.7 mmol/l glucose (3.7 +/- 0.3 vs. 2.3 +/- 0.3%, P < 0.002). We conclude that human anti-CD38 autoantibodies with agonistic properties on the CD38 effector system occur in nature; in human islets, their [Ca2+]i-mobilizing activity is coupled with the ability to stimulate insulin release.

Autoantibodies to CD38 (ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase) in Caucasian patients with diabetes: effects on insulin release from human islets.

The type II transmembrane glycoprotein CD38 (ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase) has been proposed as a mediator of insulin secretion from pancreatic beta-cells and as a candidate for autoimmune reactions in type 2 diabetes. We evaluated the presence of anti-CD38 autoantibodies in Caucasian patients with diabetes and investigated the effect of these antibodies on insulin secretion from isolated human pancreatic islets. The presence of anti-CD38 autoantibodies was evaluated by using Western blot analysis in 236 patients with type 2 diabetes (mean age 63 years), in 160 patients with type 1 diabetes (mean age 38 years), and in 159 nondiabetic subjects. Anti-CD38 autoantibody titers at least 3 SD above the mean value of the control group were found in 9.7% of type 2 diabetic patients and in 13.1% of type 1 diabetic patients (chi2 = 15.9, P = 0.0003 vs. 1.3% of control subjects). No significant differences were observed in sex distribution, current age, age at diabetes onset, BMI, fasting serum glucose, or glycemic control between anti-CD38+ and anti-CD38-diabetic patients in either the type 2 or type 1 diabetic groups. The effect of 23 anti-CD38- and 13 anti-CD38+ sera on insulin secretion at low (3.3 mmol/l) or high (16.7 mmol/l) medium glucose concentrations was evaluated in isolated human pancreatic islets. Data are medians (interquartile range). The anti-CD38+ sera potentiated insulin release both at low [95 (64) vs. 23 (12) microU/ml of control incubations, respectively, P < 0.0001] and high [271 (336) vs. a control of 55 (37) microU/ml, respectively, P = 0.001] medium glucose concentrations, whereas the anti-CD38- sera did not. Furthermore, in the pooled data from all 36 tested sera, insulin levels in the islet incubation medium were directly related to the anti-CD38 antibody titer. We conclude that autoantibodies to CD38 are associated with both type 1 and type 2 diabetes in Caucasian subjects. These autoantibodies exert a stimulatory effect on insulin secretion by cultured human islets. The role of this autoimmune reaction in the pathogenesis of diabetes remains to be elucidated.

In vivo CD30 expression in human diseases with predominant activation of Th2-like T cells.

CD30 is a member of the tumor necrosis factor (TNF) receptor family, originally described as a marker for Hodgkin and Reed-Sternberg cells in Hodgkin's disease, which has been found to be preferentially expressed by T cells producing Th2-type cytokines. The presence of CD30 expression was assessed by both immunohistochemistry and reverse transcriptase-polymerase chain reaction in the target organs of patients with Th1- or Th2-dominated disorders. CD30 expression was found in neither the gut of patients with Crohn's disease nor in the gastric antrum of Helicobacter pylori-infected patients, where there was high interferon-gamma (IFN-gamma) expression. In contrast, high CD30 expression in the apparent absence of IFN-gamma expression was observed in the skin of patients with systemic sclerosis or chronic graft versus host disease (GVHD), which can be considered Th2-dominated disorders. Moreover, high levels of soluble CD30 were found in the serum of both systemic sclerosis and GVHD patients but not in the serum of patients suffering from multiple sclerosis, a Th1-dominated disorder. Thus, CD30 expression appears to be preferentially associated with Th2-type responses not only in vitro but also in vivo.

Anti-CD38 autoimmunity in children with newly diagnosed type 1 diabetes mellitus.

AIMS: To test for anti-CD38 autoimmunity in children with newly-diagnosed type 1 diabetes mellitus (DM1). METHODS: Serum anti-CD38 autoantibodies were detected by Western blot in 270 children (130 girls, 140 boys, mean age 8 +/- 4 years) with newly-diagnosed DM1 and 179 gender- and age-matched non-diabetic children. In 126 diabetic children, another blood sample was obtained 15 +/- 4 months after the diagnosis. RESULTS: Anti-CD38 autoantibody titers at least 3 SD above the mean value for the control group were found in 4.4% of children with DM1 vs 0.6% of controls (chi2 = 5.8, p <0.016). No statistical differences were observed between anti-CD38 positive and negative patients in terms of phenotype. At follow-up, of six diabetic children who were positive for anti-CD38 antibodies, two were new cases. A positive correlation was found between the antibody titer of diabetic sera at diagnosis and follow up (r = 0.46, p <0.0001). CONCLUSION: An autoimmune reaction against CD38, a protein expressed in human islets, is associated with newly-diagnosed DM1. In children with DM1, CD38 autoimmunity increases with time and persists.

Endogenous dopamine (DA) and DA2 receptors: a mechanism limiting excessive sympathetic-adrenal discharge in humans.

We studied the effects of presynaptic dopamine (DA) 2 receptor blockade on the sympathetic-adrenal response to graded exercise in seven normal men. DA2 receptor blockade was achieved by means of domperidone (DMP) administration. The exercise consisted of progressive cycling activity, from 30-80% of the predetermined maximal oxygen consumption for each man. Systolic, diastolic, and mean arterial pressures; heart rate; and plasma norepinephrine (NE), epinephrine (E), PRL, glucose, lactate, FFA, sodium, potassium, cortisol, and PRA were measured at rest, during exercise, and during recovery after placebo or DMP administration. Graded exercise caused significant increases in systolic and mean arterial pressures and plasma NE, E, lactate, sodium, potassium, FFA, cortisol, and PRA. DMP administration before exercise caused a significant increase in plasma PRL (P = 0.0009), a greater increase in plasma NE at the end of the exercise (P = 0.002), and an overall increase in plasma E (P = 0.02) and FFA (P = 0.02) concentrations. These results strongly suggest that endogenous DA limits catecholamine release during sympathetic-adrenal stimulation by activating DA2 receptors.

Adrenal medulla secretion in Cushing's syndrome.

To investigate whether chronic endogenous hypercortisolism might alter adrenomedullary phenylethanolamine N-methyltransferase activity, we measured epinephrine/norepinephrine (E/NE) ratios in the adrenal venous blood of 8 patients undergoing surgery for Cushing's syndrome and in 12 control subjects undergoing surgery for left kidney diseases. To investigate the adrenomedullary secretory activity in Cushing's syndrome, we measured basal E plasma levels in 24 patients and 32 age- and sex-matched normal control subjects, and we evaluated the adrenomedullary response to glucagon in 9 patients and in 22 age- and sex-matched normal subjects. Last, to clarify whether chronic endogenous hypercortisolism might modify E plasma levels through a modification of E metabolism, we measured the E MCR in four patients and four age-matched controls. Mean (+/- SEM) E/NE ratio in adrenal venous blood was similar in patients with Cushing's syndrome (4.61 +/- 0.78) and in the control group (4.71 +/- 0.74). Mean (+/- SEM) basal plasma E was significantly lower in patients with Cushing's syndrome (98.2 +/- 10.9 vs. 184 +/- 25.1 pmol/L, P < 0.01) than in the control group. Similarly, plasma NE also was reduced (0.75 +/- 0.09 vs. 1.10 +/- 0.07 nmol/L, P < 0.01). In patients with Cushing's syndrome the E response to glucagon was significantly reduced (P < 0.01). E MCR was almost identical in patients with Cushing's syndrome (1.48 +/- 0.10 L/min.m2) and in control subjects (1.51 +/- 0.10 L/min.m2). Our data demonstrate that: 1) chronic endogenous hypercortisolism is not able to change adrenomedullary phenylethanolamine N-methyltransferase activity and therefore the quality of adrenomedullary secretion; and 2) chronic endogenous hypercortisolism causes a decrease in basal and stimulated adrenomedullary activity without altering E MCR significantly. Therefore the adrenal medulla does not seem to play a pathogenetic role in the hypertension of Cushing's syndrome.

Urinary endothelin-1 excretion is enhanced by low-dose infusion of brain natriuretic peptide in normal humans.

To evaluate the functional relationship between cardiac natriuretic peptides and endothelin-1 within the human kidney, we studied the effects exerted by infusion of brain natriuretic peptide on urinary endothelin-1 excretion. We studied twice in a single-blind manner five normal volunteers who received a constant infusion of 5% dextrose (250 mL/h) or human brain natriuretic peptide-32 at a dose of 4 pmol/kg per minute. Blood samples were drawn at intervals for measurement of hematocrit and concentrations of creatinine, electrolytes, brain natriuretic peptide, and endothelin-1. Urine was collected an intervals for measurement of flow rate and concentrations of creatinine, sodium, cGMP, and endothelin-1. Blood pressure and heart rate were measured every 15 minutes. Placebo administration did not change blood pressure, heart rate, or any of the other parameters measured in plasma and urine. As expected, brain natriuretic peptide infusion caused significant increases in its own plasma levels (basal versus peak levels [mean +/- SD], 1.45 +/- 0.20 versus 50.5 +/- 6.0 pmol/L, P < .01), in urinary cGMP (0.75 +/- 0.16 versus 1.92 +/- 0.81 fmol/min, P < .05), and in urinary sodium excretion (140.0 +/- 38.7 versus 624.2 +/- 181.6 mumol/min, P < .01). In addition, it caused an increase in urinary endothelin-1 excretion (4.32 +/- 2.11 versus 19.67 +/- 9.52 fmol/min, P < .05), without modifying plasma endothelin-1, blood pressure, heart rate, creatinine clearance, and urinary flow rate. Our data indicate that brain natriuretic peptide, at plasma levels comparable to those observed in patients with heart failure, causes a significant increase in urinary but not plasma endothelin-1, thus demonstrating a functional link between cardiac natriuretic peptides and renal release of endothelin-1.

Dopamine D2 receptor gene expression and binding sites in adrenal medulla and pheochromocytoma.

To determine whether dopamine D2 receptors are present in normal and neoplastic chromaffin tissues, 10 pheochromocytomas and 5 human adrenal glands were studied. Dopamine D2 receptor messenger ribonucleic acid corresponding to a single band of approximately 2.5 kilobases was detected in both pheochromocytoma and human adrenal gland by Northern blot analysis. D2 receptor messenger ribonucleic acid levels determined by dot blot analysis were 3.1-fold lower in human adrenal medullas than in pheochromocytomas (P < 0.001). Simultaneous Scatchard analysis of [3H]spiperone binding experiments demonstrated the presence of two different binding sites in membrane preparations from bovine adrenal medullas [R1: Kd = 0.14 nmol/L; binding capacity (Bmax) = 6.2 fmol/mg protein: R2: Kd = 16 nmol/L; Bmax = 223 fmol/mg protein]. Similarly, two binding sites were present in membrane preparations from pheochromocytomas (R1: Kd = 0.39 nmol/L; R2: Kd = 61 nmol/L]. Binding capacities were greatly variable among pheochromocytomas (R1: Bmax = 12.0-372.5 fmol/mg protein; R2: Bmax = 1,000-11,586 fmol/mg protein). The relative potencies of different compounds to displace [3H]spiperone were spiperone > domperidone > (+)-butaclamol > quinpirole > SCH 23390 in bovine adrenal medulla, and spiperone >> domperidone > quinpirole > (+)-butaclamol > SCH 23390 in pheochromocytoma. We conclude that dopamine D2 receptors are synthesized in human adrenal medulla and pheochromocytoma tissues.

Gene expression of endothelin-1, endothelin-converting enzyme-1, and endothelin receptors in human epididymis.

We have previously reported the presence of endothelin-1 (ET-1) and its receptors in the human testis. In the present study we extended our investigations to human epididymis. The rationale of our study originated from the fact that sperm appear to be immotile during their transit through the epididymis. Hence, it is conceivable that specific factors, unknown to date, are present in this organ, capable of inducing smooth muscle contractions, thus forcing sperm transport. In this paper it is shown that ET-1 messenger ribonucleic acid and protein are readily detectable in the epithelial compartment of the human epididymis, and that ET-converting enzyme-1, which converts the precursor pro-ET-1 into the active peptide ET-1, is expressed in the epididymis, thus indicating an active processing of the prohormone. In addition, two classes of ET receptors were characterized and located in the muscle cells of the epididymis. These receptors correspond, in terms of affinity constants and capacity, to the ETA and ETB receptors previously characterized. These receptors mediate the contractile activity of the epididymis in vitro, thus suggesting that ET-1 can be responsible of sperm progression through this organ, acting via a paracrine mode of action.

Expression and biological effects of endothelin-1 in human gonadotropin-releasing hormone-secreting neurons.

In a previous report, we demonstrated that in FNC-B4 cells, derived and characterized from a human fetal olfactory epithelium, both sex steroids and odorants regulate GnRH secretion. We now report the presence and biological activity of endothelin (ET)-1 in this GnRH-secreting neuronal cell. By in situ hybridization and immunohistochemistry, we found gene and protein expression of ET-1 and its converting enzyme ECE-1 in both fetal olfactory mucosa and FNC-B4 cells. The presence of authentic ET-1 in the conditioned media of FNC-B4 cells was further supported by combined RIAs and high-performance liquid chromatography studies. Experiments with radiolabeled ET-1 and ET-3 strongly indicated the presence of two classes of binding sites, corresponding to the ETA (16,500 sites/cell) and the ETB receptors (8,700 sites/cell). Functional studies, using selective analogs, indicated that these two classes of receptors subserve distinct functions in human GnRH-secreting cells. The ETA receptor subtype mediated an increase in intracellular calcium and GnRH secretion. Conversely, stimulation of the ETB subtype induced DNA synthesis and mitogen-activated protein kinase p44ERK1 expression. This is the first demonstration, in a human in vitro model, of a neuroendocrine role for ET-1 as regulator of GnRH-secreting neuron activity.

Insulin-like growth factor-I (IGF-I) and its binding protein IGFBP-4 in human prostatic hyperplastic tissue: gene expression and its cellular localization.

It has been previously reported that 1) type I insulin-like growth factor (IGF) receptors are present in the human prostatic tissue; 2) IGF-I receptors are mainly localized in the epithelial cells; 3) IGF-I is a mitogen for prostatic epithelial cells in culture; and 4) IGF-binding proteins (IGFBPs) are released by these cells in the conditioned medium. To add information on the mechanism of IGF-I action in the human prostate, we studied the expression and cellular localization of mRNA encoding IGF-I and IGFBP-4 in human prostatic hyperplastic (BPH) tissue. Northern analysis of total RNA extracted from BPH tissues with cDNA probes containing the entire coding regions for IGF-I and IGFBP-4 documented the presence of multiple IGF-I mRNA transcripts with lengths of 7.5, 1.7, 1.3, and 1.1 kilobases and a single 2.1-kilobase transcript of IGFBP-4 mRNA. In situ hybridization with the cDNA probes used for Northern analysis and with cRNA probes synthesized from the respective cDNA demonstrated that IGF-I mRNA was only localized in the stromal cells, whereas IGFBP-4 mRNA was predominantly expressed by epithelial cells. In addition, immunoreactive IGF-I was measured in BPH tissue extracts after acidification and reverse phase chromatography. The mean (+/- SD) IGF-I content of six BPH tissues was 28.1 +/- 4.0 ng/g tissue. Our results suggest that in the human prostate, the locally secreted IGF-I exerts its principal biological effects with a paracrine mode of action and demonstrate that IGFBP-4 is mainly expressed by IGF-I target cells.

In vivo evidence that endogenous dopamine modulates sympathetic activity in man.

Dopamine receptors type 2 (D2)-like receptor blockers cause an increase in the norepinephrine response to intense physical exercise. However, during intense physical exercise, D2-like antagonists also cause an increase in the epinephrine response, which itself might cause an increase in plasma norepinephrine through the activation of beta2 presynaptic receptors. Therefore, we evaluated the effect of domperidone, a D2-like antagonist, on the norepinephrine response to physical exercise in 6 Addison patients (3 were adrenalectomized and 3 had adrenal tuberculosis). In these patients, the norepinephrine increase observed during exercise was significantly higher after the administration of domperidone than a placebo (F=4,328; P<0.001). Because peripheral plasma norepinephrine does not reflect the sympathetic tone to the heart accurately, we evaluated the effect of domperidone administration (20 mg orally) on the sympathovagal balance, which was measured by the ratio between the high- and low-frequency components of heart rate variability, in 9 normal volunteers in the supine and sitting positions. When compared with placebo, domperidone caused a significant increase in the low/high frequency ratio (P<0.05) in the sitting position without modifying basal and stimulated norepinephrine plasma levels or blood pressure. These data support a role for endogenous dopamine in modulating norepinephrine release by human sympathetic nerves in vivo.

Dopamine modulation of pathological human chromaffin tissue.

To evaluate the presence of dopamine-2(DA2) binding sites in pheochromocytoma tissue, we performed binding studies and light microscopy autoradiography on sections of 7 different tumors. 3-H-Spiroperidol, a DA2 ligand, bound specifically to tumor sections with a (mean +/- SD) Kd value of 1.93 +/- 0.62 nmol/L. Binding site density (Bmax) was 29.16 +/- 2.33 fmol/mg tissue. Light microscopy autoradiography showed a nonhomogenous localization of silver grains within chromaffin cells. The specific binding was about 50% of total. To investigate whether DA2 binding sites found on pheochromocytoma cells might modulate catecholamine (CA) release, we studied the effects of oral bromocriptine (2.5 mg) on circulating CA of 5 patients with pheochromocytoma. In these patients bromocriptine caused a decrease in blood pressure (P less than .05) but no significant change in plasma CA. Our study shows the presence of DA2 binding sites on tumoral chromaffin tissue. As bromocriptine, a DA2 receptor agonist, was not able to modify tumor CA secretion, the functional role, if any, played by these binding sites on tumor secretion is still to be clarified.

Role for endogenous dopamine in modulating sympathetic-adrenal activity in humans.

Dopamine (DA) is synthesized and secreted in central as well as peripheral nervous system and in the adrenal medulla. Neuronal DA receptors, which have been characterized as D2 receptors, mediate an inhibition of adenylate cyclase and are located prejunctionally on sympathetic nerve endings and on chromaffin cells. Their pharmacological activation causes an inhibition of in vitro and in vivo norepinephrine (NE) release from sympathetic nerve terminals and an inhibition of in vitro epinephrine (E) release from the adrenal medulla. Endogenous DA, co-secreted with the other catecholamines (CA), modulates sympathetic-adrenal discharge only during high sympathetic stimulation through an autocrine mechanism, limiting excessive sympathetic adrenal discharge. Also pheochromocytoma cells synthesize and express D2 receptors. In patients with pheochromocytoma D2 antagonists cause hypertensive crises but the mechanism mediating this effect is still unknown as well as whether endogenous DA might modulate tumoral secretion.

Presence of dopamine-dependent adenylate cyclase activity in human renal cortex.

The effects of dopamine (DA) and of two selective DA DA1 agonists (SKF 38393 and SKF 82526) on adenylate cyclase activity were studied with human kidney cortex membrane preparations. DA elicited a dose-related stimulation of adenylate cyclase activity with an EC50 of 60 microM. The selective DA DA1 antagonist SCH 23390 behaved as a competitive antagonist, shifting the dose-response curve to the right. The non-selective beta-adrenoceptor antagonist (-)-propranolol did not affect the EC50 of the dose-response curve to DA but attenuated the maximal stimulatory effect of DA at concentrations higher than 100 microM. (+)-Sulpiride inhibited DA-induced adenylate cyclase stimulation in a dose-dependent manner with an IC50 of 4.6 X 10(-8) M but (-)-sulpiride was without effect. Both SKF 38393 and SKF 82526 stimulated the adenylate cyclase activity of human kidney cortex; this effect was completely antagonized by SCH 23390. Our results, demonstrating the presence of DA-sensitive adenylate cyclase activity, strongly suggest the presence of a DA receptor of the DA1 subtype in human kidney cortex.

Endothelin-1 is synthesized and biologically active in human epididymis via a paracrine mode of action.

In a previous study, we reported the presence of endothelin-1 and endothelin receptors in the human testis. We have now extended our investigations to the human epididymis. Since sperm appear to be immotile during their transit through the epididymis, it is conceivable that specific local factors promote smooth muscle contraction, enabling sperm transport. In this paper, we show that endothelin-1 mRNA and protein are readily detectable in the epithelial compartment of the human epididymis, and that endothelin converting enzyme- 1, which converts the precursor pro-endothelin-1 into active endothelin-1, is expressed in the epididymis, consistent with active processing of the prohormone. In addition, two classes of endothelin receptors were characterized and located in the muscle cells of the epididymis. These receptors correspond, in terms of affinity constants and capacity, to the previously characterized endothelinA and endothelinB receptor. These receptors appear to be biologically active and mediate the contractile activity of the epididymis in vitro. Our data suggest that endothelin-1, via a paracrine mode of action, may be responsible for sperm progression through this organ.

[Diagnostic problems in pheochromocytoma]. / Problemi diagnostici nel feocromocitoma.

Pheochromocytoma is mainly characterized by a great deal of variability in its biological activity and in its clinical manifestations. This special feature has always to be taken into account in any diagnostic procedure. The tumor is generally suspected on clinical ground for the presence of paroxysmal hypertension but this sign is largely aspecific and often absent. The diagnosis of pheochromocytoma has to be based on laboratory tests demonstrating an excess and/or a disregulation in catecholamine (CA) secretion. CA or CA metabolites can be measured in urine or blood. Whatever the sample measured, it is important to correlate its result with the clinical picture found during its collection. Basal plasma CA concentrations are often raised also during periods of normotension but their accuracy is the highest in samples drawn during a hypertensive crisis. When basal measurements are insufficient for a final diagnosis, inhibitory (clonidine) or stimulatory (glucagon) tests can be performed. Clonidine test is recommended in patients showing slight increases in basal plasma CA. Glucagon stimulation test should be performed only in normotensive patients with an incidental adrenal mass, patients with sporadic hypertensive crises or members of families affected by MEN II. Localization procedures are mainly based on CT (or MRI) and on scintigraphy with I131-MIBG. CT possesses high sensitivity (about 96%) while I131-MIBG scintigraphy possesses a very high specificity (about 97%). Therefore, both the procedures should be performed before surgery. Rarely, it is also necessary to perform catheterization of the venous tree and plasma sampling for CA measurement to localize the tumor through the discovery of a secretory gradient.

Circulating BRAFV600E in the diagnosis and follow-up of differentiated papillary thyroid carcinoma.

CONTEXT: Cell-free nucleic acids circulating in plasma are considered a promising noninvasive tool for cancer monitoring. BRAF(V600E) mutation in cell-free DNA (cfDNA) could represent an appropriate marker for papillary thyroid carcinoma (PTC). OBJECTIVE: Our aim is to investigate the role of BRAF(V600E)-mutated allele in cfDNA as a marker for the diagnosis and follow-up of PTC. STUDY DESIGN: BRAF(V600E) allele was detected and quantified by an allele-specific real-time quantitative PCR assay in plasma from 103 patients affected by nodular goiter. As control populations, we enrolled 49 healthy subjects and 16 patients with non-nodular thyroid diseases. RESULTS: The percentage of circulating BRAF(V600E) was significantly different between patients and controls and throughout different cytological categories of ultrasound-assisted fine-needle aspiration. Patients with a histopathological diagnosis of PTC showed a higher percentage of circulating BRAF(V600E) (P = .035) compared to those with benign histology. In 19 patients, a second blood draw, taken 3-6 months after surgery, showed a lower percentage of BRAF(V600E) in cfDNA than the presurgical sample (P < .001). The diagnostic performance of circulating BRAF(V600E) was assessed by receiver operating characteristic curve analysis resulting in an area under the curve of 0.797. A cutoff value was chosen corresponding to maximum specificity (65%) and sensitivity (80%). On this basis, we evaluated the predictive value of BRAF(V600E) in Thy 3 patients with a resulting positive predictive value of 33% and a negative predictive value of 80%. CONCLUSIONS: The results of the present study provide encouraging data supporting the possibility to take advantage of circulating BRAF(V600E) in the management of PTC.