Pronounced dys-autonomic symptoms announcing a primary Sjögren's syndrome.

Sjögren's syndrome (SS) is an autoimmune disease that involves the nervous system in about 20% of cases. In 25-92% of patients affected by Sjögren's syndrome, neurological symptoms may precede the sicca syndrome. A 65-year-old male presented with a seven-month history of episodes of near-syncope, constipation, anhidrosis, disabling fatigue and asthenia. Physical examination was unremarkable, whilst the ECG revealed sinus bradycardia. Laboratory tests showed lymphopenia and normal inflammatory markers. In order to assess a potential autonomic neuropathy, "Deep Breathing Test" (E/I 1.02), "Lying to Standing Test" (R/R' 0.95), and "Orthostatic Hypotension Tests" (T 120s Systolic reduction >20 mmHg and Diastolic reduction >10 mmHg) were performed, all of which were abnormal. ECG Holter monitoring revealed sinus bradycardia, and right bundle branch block with 24-h blood pressure monitoring revealing a diurnal hypotensive profile. The patient reported a three-month history of worsening dry mouth. On physical examination, the patient had anisocoria in response to light stimulation. Auto-antibody testing was performed to evaluate the presence of any autoimmune disease. The results of these studies included an abnormal elevation of ANA (1:320 speckled pattern), Ro/SS-a (>240U/l), and La/SS-b (162 U/ml) antibodies. The patient was discharged with a diagnosis of "Autonomic Neuropathy Most Likely Due to Primary Sjögren's Syndrome (SS)" and started the immunotherapy. After one month, he reported a significant improvement in his symptoms with a concomitant normalization of his "Orthostatic Hypotension Tests." This case underlines the potential for dys-autonomic symptoms to precede the onset of sicca syndrome in patients with Sjogren's Syndrome.

Mesenteric cyst and recurrent abdominal pain in a patient with Gorlin-Goltz syndrome: a case report.

Gorlin-Goltz syndrome (GGS) is an infrequent autosomal do-minant multisystemic disease with complete penetrance and variable expressivity. It is estimated to have an incidence of 1:50,000 - 1:150,000 cases with a M/F = 1:1. This report describes a case of recurrent abdominal pain due to a large mesenteric cyst in a 38-year-old female patient affected by a rare disease: Gorlin-Goltz syndrome.

Predictive factors of difficult procedure in octogenarians undergoing elective laparoscopic cholecystectomy: a single center experience.

AIM: To assess the feasibility and safety of laparoscopic cholecystectomy (LC) in very elderly patients with particular attention to the predicitive factors of difficulty. PATIENTS AND METHODS: All patients aged ≥ 80 undergoing elective LC for lithiasis at our institution since 1st January 2015 to 31st December 2015 were included in the study. Exclusion criteria were: a) acute cholecystitis; b) biliary pancreatitis; c) biliary tract neoplasms; d) urgent procedure. Pre-, intra- and postoperative data were recorded. RESULTS: During the study period, we performed 72 LC and we enrolled 17 patients aged ≥ 80 with a M:F = 5:12. Of these, 10 patients had a "difficult" cholecystectomy. In seven cases an intraoperative cholangiography (IOC) was performed. Postoperative course was regular but in two patients we had an Oddian spasm in 1st postoperative day. Female sex (p=0.03) and preoperative high level of serum amylase (p= 0.02) were significantly associated to difficult cholecystectomy in elderly patients. CONCLUSION: LC in octogenarians is feasible and safe. However, sex and serum amylase can help the surgeon to predict a more difficult procedure in elective LC. In this group of patients an approach based on the individual risk is desirable and the patient could be referred to a multidisciplinary approach.

Application and internal validation of lung ultrasound score in COVID-19 setting: The ECOVITA observational study.

BACKGROUND: The severe acute respiratory syndrome Coronarovirus-2 associated still causes a significant number of deaths and hospitalizations mainly by the development of respiratory failure. We aim to validate lung ultrasound score in order to predict mortality and the severity of the clinical course related to the need of respiratory support. METHODS: In this prospective multicenter hospital-based cohort study, all adult patients with diagnosis of SARS-CoV-2 infection, performed by real-time reverse transcription polymerase chain reaction were included. Upon admission, all patients underwent blood gas analysis and lung ultrasound by expert operators. The acquisition of ultrasound scan was performed on 12 peculiar anatomic landmarks of the chest. Lung ultrasound findings were classified according to a scoring method, ranging 0 to 3: Score 0: normal A-lines. Score 1: multiple separated B-lines. Score 2: coalescent B-lines, alteration of pleural line. Score 3: consolidation area. RESULTS: One thousand and seven patients were included in statistical analysis (male 62.4 %, mean age 66.3). Oxygen support was needed in 811 (80.5 %) patients. The median ultrasound score was 24 and the risk of having more invasive respiratory support increased in relation to higher values score computed. Lung ultrasound score showed negative strong correlation (rho: -0.71) with the P/F ratio and a significant association with in-hospital mortality (OR 1.11, 95 %CI 1.07-1.14; p < 0.001), even after adjustment with the following variables (age, sex, P/F ratio, SpO2, lactate, hypertension, chronic renal failure, diabetes, and obesity). CONCLUSIONS: The novelty of this research corroborates and validates the 12-field lung ultrasound score as tool for predicting mortality and severity clinical course in COVID-19 patients. Baseline lung ultrasound score was associated with in-hospital mortality and requirement of intensive respiratory support and predict the risk of IOT among COVID-19 patients.

Search for compensation postures with videofluoromanometric investigation in dysphagic patients affected by amyotrophic lateral sclerosis.

PURPOSE: This study was undertaken to verify the effectiveness of compensatory postures, suggested on the basis of the type of dysphagia identified at videofluoromanometric (VFM) investigation to ensure safe oropharyngeal transit. MATERIALS AND METHODS: Eighty-one patients with amyotrophic lateral sclerosis (ALS) underwent speech therapy assessment and VFM investigation of the swallowing process. In the event of altered transit, penetration or aspiration of contrast material into the airways, compensation postures for correction of the swallowing disorder were suggested and verified during VFM examination. RESULTS: In 37 patients, contrast agent transport was preserved and safe; in 19, we observed penetration of the contrast agent into the laryngeal inlet without aspiration; in 24, there was aspiration (four preswallowing, eight intraswallowing, nine postswallowing, three mixed), whereas in one patient no transit was seen. Penetration without aspiration was resolved by coughing or throat clearing; aspiration was resolved in 13 patients by assuming the chin-tuck posture and in six by rotating the head; in five patients, it was not resolved. A hyperextended head posture proved to be effective to resolve lack of transit. CONCLUSIONS: By correlating morphological with functional data, VFM enables one not only to precisely characterise the dysphagic disorder but also to identify the most appropriate compensation posture for each patient and verify its effectiveness.

An apparatus for the continuous measurement of thickness during the electropolishing of superconducting cavities.

An apparatus allowing continuous acquisition of thickness measurements during electropolishing of superconducting cavities is described. The instrument is based on the ultrasound thickness measurement technique and allows the connection of up to six probes. The apparatus has been employed to monitor the surface treatment of PIP-II low beta single cell prototypes developed and manufactured by LASA-INFN and specifically to measure surface removal at different points of interest on the cavity surface. The apparatus facilitated the development and optimization of electropolishing parameters for incorporation into the cavity manufacturing process.

A new radioguided procedure for localization and surgical treatment of neck node metastasis of papillary thyroid cancer.

AIM OF THE STUDY: We intended to use a radioguided technique for pre-operative localization of neck node recurrences in patients with papillary thyroid cancer (PTC) already submitted to thyroidectomy and radioiodine treatment. PATIENTS AND METHODS: We selected 20 patients affected by PTC with evidence of neck nodes recurrences at ultrasound examination. Our method has been derived from the Radioguided Occult Lesion Localization technique used for pre-operative localization of occult breast lesions. The technique involves the inoculation of human albumin macroaggregates labeled with radioactive technetium (0.4 mCi in a volume of 0.05 ml) directly in the suspicious lesion, under ultrasound guidance. The persistence of the radioactive tracer in the nodes is confirmed by a scintigraphy performed 2 h after injection. During surgery, a gamma detecting probe is used to locate the suspicious lesions as "hot spots". RESULTS: Fifty lymph-nodes were injected with the tracer. All radiolabeled lymph-nodes were located and removed during surgery. At histology, metastasis of PTC was confirmed in 38/50 (76%) lymph-nodes. At least one metastatic lymph-node per patient was removed. In 8/20 (40%) patients, reactive lymphoid hyperplasia was found in 12/50 (24%) lymph-nodes. CONCLUSIONS: This radioguided technique has been highly effective for localization and surgical treatment of suspicious lymph-node detected at neck ultrasound and may play a valuable role in case of node metastases of thyroid cancer that show no radioiodine uptake.

Requirement of Rsk-2 for epidermal growth factor-activated phosphorylation of histone H3.

During the immediate-early response of mammalian cells to mitogens, histone H3 is rapidly and transiently phosphorylated by one or more unidentified kinases. Rsk-2, a member of the pp90rsk family of kinases implicated in growth control, was required for epidermal growth factor (EGF)-stimulated phosphorylation of H3. RSK-2 mutations in humans are linked to Coffin-Lowry syndrome (CLS). Fibroblasts derived from a CLS patient failed to exhibit EGF-stimulated phosphorylation of H3, although H3 was phosphorylated during mitosis. Introduction of the wild-type RSK-2 gene restored EGF-stimulated phosphorylation of H3 in CLS cells. In addition, disruption of the RSK-2 gene by homologous recombination in murine embryonic stem cells abolished EGF-stimulated phosphorylation of H3. H3 appears to be a direct or indirect target of Rsk-2, suggesting that chromatin remodeling might contribute to mitogen-activated protein kinase-regulated gene expression.

[Cryptococcosis in AIDS patients: case study from 1996 to 2006 in Paroissien Hospital]. / Criptococosis en pacientes con SIDA: estudio de casos en el Hospital Paroissien en el período 1996-2007.

Clinic, epidemiological and microbiological characteristics of 128 episodes of cryptococcosis were retrospectively evaluated in 106 positive HIV patients hospitalized at the Paroissien Hospital on period 1996-2007. There were 75 male and 31 female patients, with a median age of 34 years, ranging from 20 to 68 years. Addiction to intravenous drugs was the main cause of HIV infection in 55 patients (51.9%). Cryptococcosis was detected as single episode in 85 patients (80.2%) and as relapse in 19 (17.9%). It appeared as the first marking disease in 36 patients (34.0%). Diagnosis was established in 116 episodes by CSF study (Indian ink, culture, antigen detection), in 9 cases by Cryptococcus sp. recovery from blood cultures, and in 3 cases by antigen detection in patient's serum with a latex reactive. Neurological symptomatology, with headache and fever as the most common signs, was presented by 89.6% of patients. Induction treatment was done in all cases with amphotericin B, and maintenance treatment was carried out with fluconazole. Mortality rate was 35.8%, being higher in those patients who had suffered relapses (41.3%) compared to those who presented a first episode of the mycosis (33.3%).

Saporin as a novel suicide gene in anticancer gene therapy.

We used a non-viral gene delivery approach to explore the potential of the plant saporin (SAP) gene as an alternative to the currently employed suicide genes in cancer therapy. Plasmids expressing cytosolic SAP were generated by placing the region encoding the mature plant ribosome-inactivating protein under the control of cytomegalovirus (CMV) or simian virus 40 (SV40) promoters. Their ability to inhibit protein synthesis was first tested in cultured tumor cells co-transfected with a luciferase reporter gene. In particular, SAP expression driven by CMV promoter (pCI-SAP) demonstrated that only 10 ng of plasmid per 1.6 x 10(4) B16 cells drastically reduced luciferase activity to 18% of that in control cells. Direct intratumoral injection of pCI-SAP complexed with either lipofectamine or N-(2,3-dioleoyloxy-1-propyl) trimethylammonium methyl sulfate (DOTAP) in B16 melanoma-bearing mice resulted in a noteworthy attenuation of tumor growth. This antitumor effect was increased in mice that received repeated intratumoral injections. A SAP catalytic inactive mutant (SAP-KQ) failed to exert any antitumor effect demonstrating that this was specifically owing to the SAP N-glycosidase activity. Our overall data strongly suggest that the gene encoding SAP, owing to its rapid and effective action and its independence from the proliferative state of target cells might become a suitable candidate suicide gene for oncologic applications.

Cross-talk in signal transduction: Ras-dependent induction of cAMP-responsive transcriptional repressor ICER by nerve growth factor.

The CREM gene encodes both activators and repressors of cAMP-induced transcription. By virtue of an alternative, intronic promoter within the gene, the ICER (Inducible cAMP Early Repressor) isoform is generated. ICER acts as a dominant negative regulator and is cAMP-inducible in various neuroendocrine cells and tissues. ICER negatively autoregulates its own expression, and appears to participate in the molecular events governing oscillatory hormonal regulations. Here we report that ICER is inducible with nerve growth factor (NGF). This is the first example of cAMP-independent induction of ICER expression. Importantly, induction by NGF occurs via a subset of the CREs present in the ICER promoter which were previously shown to direct cAMP-inducibility. ICER induction correlates with a NGF-mediated phosphorylation of CREB. Both CREB phosphorylation and ICER inducibility require an intact Ras-dependent signalling pathway. We show that increased ICER levels result in the attenuation of c-fos expression. The activation of a powerful repressor of cAMP-responsive transcription by NGF, whose transduction signalling is cAMP-independent, constitutes a notable example of nuclear cross-talk and thus is likely to have relevant physiological implications.

A new Chinese hamster ovary cell line expressing alpha2,6-sialyltransferase used as universal host for the production of human-like sialylated recombinant glycoproteins.

Chinese hamster ovary (CHO) cells are widely employed to produce glycosylated recombinant proteins. Our group as well as others have demonstrated that the sialylation defect of CHO cells can be corrected by transfecting the alpha2,6-sialyltransferase (alpha2,6-ST) cDNA. Glycoproteins produced by such CHO cells display both alpha2,6- and alpha2,3-linked terminal sialic acid residues, similar to human glycoproteins. Here, we have established a CHO cell line stably expressing alpha2,6-ST, providing a universal host for further transfections of human genes. Several relevant parameters of the universal host cell line were studied, demonstrating that the alpha2,6-ST transgene was stably integrated into the CHO cell genome, that transgene expression was stable in the absence of selective pressure, that the recombinant sialyltransferase was correctly localized in the Golgi and, finally, that the bioreactor growth parameters of the universal host were comparable to those of the parental cell line. A second step consisted in the stable transfection into the universal host of cDNAs for human glycoproteins of therapeutic interest, i.e. interferon-gamma and the tissue inhibitor of metalloproteinases-1. Interferon-gamma purified from the universal host carried 40.4% alpha2,6- and 59.6% alpha2,3-sialic acid residues and showed improved pharmacokinetics in clearance studies when compared to interferon-gamma produced by normal CHO cells.

A rat Sertoli cell factor similar to basic fibroblast growth factor increases c-fos messenger ribonucleic acid in cultured Sertoli cells.

We have shown that the cultured Sertoli cell from the immature rat contains a fibroblast growth factor (FGF)-like factor. It behaves as a cationic peptide, is a potent competence factor for BALB/c3T3 mouse embryo fibroblasts, and displays a high affinity for heparin. Both bovine basic FGF and Sertoli cell FGF-like factor rapidly increase c-fos mRNA in cultured Sertoli cells. FSH, serum, and phorbol esters individually stimulate c-fos in cultured Sertoli cells whereas platelet-derived growth factor, epidermal growth factor, and insulin-like growth factor-I have little affect. However, unlike FSH, basic FGF does not stimulate an increase in cAMP and unlike either serum or phorbol esters, basic FGF does not stimulate phosphoinositol turnover or intracellular calcium changes. When Sertoli cell protein kinase C activity is suppressed by preexposure to phorbol ester, basic FGF continues to be a potent stimulator of c-fos, indicating that the calcium/phospholipid pathway is not involved in FGF induction. Basic FGF and FSH also increase jun-B mRNA levels in cultured Sertoli cells. In response to FGF, jun-B is more transiently increased than c-fos. In contrast, in response to FSH, jun-B persists longer than c-fos. These results indicate that cultured Sertoli cells contain a FGF-like factor that increases c-fos mRNA via a mechanism not involving cAMP and the calcium/phospholipid pathways. The different responsiveness of c-fos and jun-B to FSH and basic FGF may explain differences in the ultimate actions of these two ligands.

Hormonal and developmental regulation of DAX-1 expression in Sertoli cells.

Mutations in the human DAX-1 gene lead to X-linked adrenal hypoplasia congenita and hypogonadotropic hypogonadism. DAX-1 has been proposed to play a role in steroidogenesis because it is highly expressed in adrenocortical and testicular Leydig cells and because loss-of-function mutations lead to low serum levels of steroid hormones. Recent reports of DAX-1 expression in hypothalamus and pituitary, however, suggest additional functions for this protein. Here we demonstrate that DAX-1 is expressed in Sertoli cells of rat testis. This expression is regulated during spermatogenesis and peaks during the androgen-sensitive phase of the spermatogenic cycle. In addition, we show that DAX-1 expression in Sertoli cells is regulated developmentally. Maximum levels are present in the rat between postnatal days 20 and 30, during the first spermatogenic wave. Moreover, we show that activation of the cAMP-signaling pathway by the pituitary hormone FSH leads to a potent down-regulation of DAX-1 expression in cultured Sertoli cells. This down-regulation requires transcription and de novo protein synthesis. Taken together, these data indicate that DAX-1 expression in Sertoli cells may influence the development of spermatogenic cells in response to steroid and pituitary hormones.

Gastric cancer in the elderly patient.

The incidence of gastric cancer is increasing in elderly patients, unlike what it's being observed in the younger patients. The aim of this study is to evaluate the impact of the age on the resecability, resection type (R0-R1-2), morbidity, mortality and survival rate. The higher mortality observed in the elderly patients, the discussed role of an extended lymphadenectomy and the poor survival rate, would lead to a surgical approach which mostly tends to the palliation of the symptoms than the obtainment of a curative resection. But, on the other hand, the impossibility of making chemotherapy in most of the over 75 year old patients, lead us to a R0 surgery treatment.

[Ultrasound-guided vacuum-assisted biopsy: review of 382 cases]. / Macrobiopsies assistées par le vide sous guidage échographique: à propos de 382 cas.

PURPOSE: To evaluate the use of US-guided vacuum biopsy for diagnosis and treatment of probably benign breast masses. MATERIALS AND METHOD: Retrospective review of 382 US guided vacuum biopsies over a 44 months period (september 2001 to may 2005) with the 11-g handheld mammotome. A total of 308 benign tumors, 59 borderline lesions and 15 carcinomas were diagnosed. The average number of specimens is 13.1 (3-37). Surgical resection has been systematic for carcinomas and selective for papillomas. Surgical correlation (n:35) or mammographic follow-up (n:347) are presented. RESULTS: Complete removal occurred in 371/382 (97.1%) immediately after biopsy and 337/382 (88.2%) after one month: 138/142 (93.7%) for fibroadenomas and 52/53 (98.1%) papillomas less than 15 mm. Open surgical biopsy was carried out for 35 patients on the basis of incomplete removal (3 cases) or histologic findings (8 invasive carcinomas, 7 ductal carcinoma in situ, 3 atypical ductal hyperplasia, 1 fibrocystic changes with atypia and 11 papillomas). No lesion was under-diagnosed and the rate of avoided surgery was 94.5%. Of the 347 lesions that were not surgically biopsied (42 borderline lesions and 305 benign lesions), 337 were monitored at 1-43 months (average: 20 months, > or =24 months: 57 patients). Ten underwent additional biopsy but no missed cancer was detected. Patients tolerance was good or very good in 83%, and the complication rate was 1.3%. CONCLUSION: US-guided vacuum biopsy is an accurate and well tolerated technique. It is an alternative to surgery for masses less than 15 mm including fibroadenomas and papillomas or in patients with imaging-histologic discordance at core biopsy.

Nonviral gene delivery to the rat kidney with polyethylenimine.

The aim of this study was to establish a nonviral method for gene delivery to the rat kidney. To this purpose, a panel of reagents was tested, including a monocationic lipid, DOTAP, a polycationic lipid, DOGS (or Transfectam), and three different forms of the cationic polymer polyethylenimine (PEI). A comparison among these compounds was performed in vivo, using luciferase as reporter gene. Complexes containing 10 microg of DNA were injected into the left renal artery of rats and allowed to remain in contact with the kidney for 10 min. Forty-eight hours later, luciferase expression levels in kidney extracts were measured. Kidneys injected with DNA complexed to the branched, 25-kD PEI polymer (PEI 25k) yielded activity levels significantly higher than control, sham-operated kidneys (2.7 x 10(4) vs. 5.2 x 10(3) RLU/kidney, respectively), whereas the other transfecting agents did not yield significant activity over controls. PEI 25k was therefore chosen for further optimization of transfection conditions. Dose-dependent luciferase expression was shown for 10, 50, and 100 microg of PEI-complexed DNA, reaching maximal levels of 2.4 x 10(5) RLU/kidney at 100 microg DNA. The optimal PEI nitrogen/DNA phosphate molar ratio was 10 equivalents. Luciferase activity peaked at 2 days, was still significantly higher than controls at 7 days, and was undetectable at 14 days post-injection. Using beta-galactosidase (beta-Gal) as a reporter, transgene expression was localized almost exclusively in proximal tubular cells.

Follicle-stimulating hormone modulation of phosphoinositide turnover in the immature rat Sertoli cell in culture.

The possibility that FSH modulates the Ca++-, phospholipid-dependent pathway was studied in cultured rat Sertoli cells. Cells were metabolically labeled with [3H]myoinositol, and accumulation of [3H]inositol phosphates [( 3H]inositol mono-, di-, and trisphosphates) was measured by extraction and fractionation on ion exchange chromatography. Fetal bovine serum increased Sertoli cell phosphoinositide (PI) turnover in a time and concentration-dependent manner (ED50 = 2-3% vol/vol). FSH by itself had no significant effect on the accumulation of inositol phosphates. On the other hand, FSH inhibited, in a concentration-dependent manner, the serum-stimulated accumulation of inositol phosphates by more than 50%. HPLC ion exchange chromatography of the inositol phosphates showed that all isomers present in serum-stimulated extracts were reduced to the same extent after treatment with FSH. The treatment of the cells with either forskolin, the beta-adrenergic agonist isoproterenol, or (Bu)2cAMP also inhibited the PI turnover stimulated by fetal bovine serum. FSH inhibition was not detected in mature Sertoli cells, in which FSH no longer stimulates cAMP accumulation. These results demonstrate that FSH, via formation of cAMP, exerts inhibitory effects on the PI turnover of the Sertoli cell. Thus, while stimulating the cAMP-dependent pathway, at the same time FSH inhibits the Ca++-, phospholipid-dependent pathway.

Purine modulation of the hormonal response of the rat Sertoli cell in culture.

To investigate the possibility that purines modulate the response of testicular cells to gonadotropin, binding of adenosine analogs and biological responses to adenosine were evaluated in Sertoli cell-enriched cultures. The adenosine analog cyclohexyladenosine bound specifically to a crude particulate fraction prepared from such cultures. Binding was saturable, and steady state studies showed the presence of a high affinity binding site (Kd = 2.1 +/- 0.3 nM; n = 4) and a receptor density of 200-300 fmol/mg protein. The bound radioactive ligand was displaced by N6-phenylisopropyladenosine (PIA), adenosine, and methylisobutylxanthine. In addition to the presence of a specific binding site, purines modulated the biological function of the Sertoli cell. The adenosine analog PIA inhibited both the FSH-dependent cAMP response and the FSH-stimulated androgen aromatization. Under all experimental conditions, the IC50 of PIA was 1-3 nM, and maximal effects were observed at 10-100 nM PIA. Adenosine itself inhibited the FSH-dependent response of the Sertoli cell, but was less potent than PIA. In addition, purine inhibition of the FSH response was antagonized by methylisobutylxanthine, while the nonxanthine phosphodiesterase inhibitor Ro 20-1724 [4-(3-butoxy-4-methoxybenzyl)2-imidazolidinone] was without effect. Purine modulation was evident not only when cells were stimulated with FSH, but also when the androgen aromatization was augmented by the beta-adrenergic agonist isoproterenol, cholera toxin, and forskolin. On the contrary, the purines had no effect when cells were stimulated with (Bu)2cAMP. The data reported are consistent with the presence of purine inhibitory receptors in Sertoli cell-enriched cultures and show that purines can regulate the response of the immature Sertoli cell in vitro.

Effect of phosphodiesterase inhibitors on Sertoli cell refractoriness: reversal of the impaired androgen aromatization.

Responsiveness of the Sertoli cell after FSH pretreatment was evaluated in terms of androgen aromatization. Sertoli cell cultures were preincubated with FSH for 24 h, then cells were washed free of hormone and reincubated with FSH in the presence of androstendione. The estrogen accumulated in the medium was measured by RIA. Gonadotropin pretreatment produced a marked refractory state, and a second challenge with FSH did not produce an increase in androgen aromatization. A dose-response study showed that FSH pretreatment produced three separate effects on Sertoli cell steroidogenesis: an increased basal production of estrogen; a decreased maximal response when doses of 10 ng/ml FSH or higher were employed in the preincubation; and a decreased sensitivity of the Sertoli cell to FSH. In the last case, the ED50 was reduced approximately 3- to 5-fold. Such an impaired stimulation of androgen aromatization was no longer present when cells were incubated with the phosphodiesterase inhibitors methyl-isobutyl-xanthine (MIX). In the presence of this inhibitor, refractory cells responded to FSH better than the control cells. The possibility that MIX stimulated cAMP accumulation by acting as antagonist of purine receptor was ruled out by the finding that the nonxanthine phosphodiesterase inhibitor 4-(3-butoxy-4-methoxybenzyl)2-imidazolidinone (Ro 20-1724) also reverted the refractory state. Pretreatment of the Sertoli cells with FSH produced an impaired response in the second incubation also to isoproterenol, cholera toxin, and forskolin. The response to these compounds was apparently normal when cells were incubated in the presence of MIX or Ro 20-1724. Conversely, refractory cells responded to (Bu)2cAMP in a manner indistinguishable from the fully responsive control cells. These data demonstrate that FSH induces homologous and heterologous refractory states of the Sertoli cell reflected by an impaired estrogen production. The finding that phosphodiesterase inhibitors fully restore the FSH response suggests an important role of phosphodiesterase in the induction and/or maintenance of such refractoriness.