IDEAL study: A real-world assessment of pattern of use and clinical outcomes with recombinant coagulation factor IX albumin fusion protein (rIX-FP) in patients with haemophilia B in Italy

INTRODUCTION

Factor IX replacement therapy is used for treatment and prophylaxis of bleeding in haemophilia B. rIX-FP is an extended half-life albumin-fusion protein, which, in clinical studies, has demonstrated prolonged dosing intervals up to 21 days for routine prophylaxis, providing therapeutic benefit.

AIMS

To describe dosing frequency and consumption (primary endpoint), efficacy and safety of rIX-FP treatment during routine clinical practice in Italy.

METHODS

Patients with moderate/severe haemophilia B on prophylaxis with rIX-FP for ≥6 months, were enrolled in this observational study from October 2017 to February 2019 and followed-up for 2 years. Descriptive analysis included prospective and retrospective data (12 months prior to switching to rIX-FP).

RESULTS

Data were collected from 59 male patients (median age 30.1 years) enrolled by 23 Italian centres. Of them, 50 were on prophylaxis during the entire observation period and completed the study. The infusion frequency changed from 2-3 times/week in 86.0% of patients with previous treatment, to less than once a week in 84.0% of patients treated with rIX-FP at the 2nd-year follow-up. The annual number of infusions decreased by about 70%, whereas the mean FIX activity trough level increased from 3.8% to 14.4% (mean > 10% in all the infusion regimens). Median Annualised Bleeding Rate of .0 was achieved across all prophylaxis regimens. Subjects with zero bleedings increased from 66.0% to 78.0% with rIX-FP.

CONCLUSION

Treatment with rIX-FP reduced infusion frequency, while providing higher FIX trough levels with substantial benefit in terms of annualised bleeding rate and a good safety profile.

Axon outgrowth and neuronal differentiation defects after a-SMN and FL-SMN silencing in primary hippocampal cultures

Spinal Muscular Atrophy (SMA) is a severe autosomal recessive disease characterized by selective motor neuron degeneration, caused by disruptions of the Survival of Motor Neuron 1 (Smn1) gene. The main product of SMN1 is the full-length SMN protein (FL-SMN), that plays an established role in mRNA splicing. FL-SMN is also involved in neurite outgrowth and axonal transport. A shorter SMN isoform, axonal-SMN or a-SMN, displays a more specific axonal localization and has remarkable axonogenic properties in NSC-34. Introduction of known SMA mutations into the a-SMN transcript leads to impairment of axon growth and morphological defects similar to those observed in SMA patients and animal models. Although there is increasing evidence for the relevance of SMN axonal functions in SMA pathogenesis, the specific contributions of FL-SMN and a-SMN are not known yet. This work aimed to analyze the differential roles of FL-SMN and a-SMN in axon outgrowth and in neuronal homeostasis during differentiation of neurons into a mature phenotype. We employed primary cultures of hippocampal neurons as a well-defined model of polarization and differentiation. By analyzing subcellular localization, we showed that a-SMN is preferentially localized in the growing axonal compartment. By specifically silencing FL-SMN or a-SMN proteins, we demonstrated that both proteins play a role in axon growth, as their selective down-regulation reduces axon length without affecting dendritic arborization. a-SMN silencing, and in minor extent FL-SMN silencing, resulted in the growth of multi-neuritic neurons, impaired in the differentiation process of selecting a single axon out of multiple neurites. In these neurons, neurites often display mixed axonal and dendritic markers and abnormal distribution of the axonal initial segment protein Ankirin G, suggesting loss of neuronal polarity. Our results indicate that a-SMN and FL-SMN are needed for neuronal polarization and organization of axonal and dendritic compartments, processes that are fundamental for neuronal function and survival.

Different Stability and Proteasome-Mediated Degradation Rate of SMN Protein Isoforms

The key pathogenic steps leading to spinal muscular atrophy (SMA), a genetic disease characterized by selective motor neuron degeneration, are not fully clarified. The full-length SMN protein (FL-SMN), the main protein product of the disease gene SMN1, plays an established role in the cytoplasm in snRNP biogenesis ultimately leading to mRNA splicing within the nucleus. It is also involved in the mRNA axonal transport. However, to what extent the impairment of these two SMN functions contributes to SMA pathogenesis remains unknown. A shorter SMN isoform, axonal-SMN or a-SMN, with more specific axonal localization, has been discovered, but whether it might act in concert with FL-SMN in SMA pathogenesis is not known. As a first step in defining common or divergent intracellular roles of FL-SMN vs a-SMN proteins, we here characterized the turn-over of both proteins and investigated which pathway contributed to a-SMN degradation. We performed real time western blot and confocal immunofluorescence analysis in easily controllable in vitro settings. We analyzed co-transfected NSC34 and HeLa cells and cell clones stably expressing both a-SMN and FL-SMN proteins after specific blocking of transcript or protein synthesis and inhibition of known intracellular degradation pathways. Our data indicated that whereas the stability of both FL-SMN and a-SMN transcripts was comparable, the a-SMN protein was characterized by a much shorter half-life than FL-SMN. In addition, as already demonstrated for FL-SMN, the Ub/proteasome pathway played a major role in the a-SMN protein degradation. We hypothesize that the faster degradation rate of a-SMN vs FL-SMN is related to the protection provided by the protein complex in which FL-SMN is assembled. The diverse a-SMN vs FL-SMN C-terminus may dictate different protein interactions and complex formation explaining the different localization and role in the neuronal compartment, and the lower expression and stability of a-SMN.

Subclinical central inflammation is risk for RIS and CIS conversion to MS

Background:

Subtle diffuse intrathecal inflammation is undetectable by conventional neuroimaging, and could influence multiple sclerosis (MS) disease course.

Objective:

To explore the role of subclinical persisting intrathecal inflammation in radiologically isolated syndrome (RIS) or clinically isolated syndrome (CIS) conversion to MS, and in early MS disease reactivation.

Methods:

One-hundred ninety-three subjects with RIS, CIS, relapsing–remitting (RR), or primary progressive (PP) MS were included, along with 76 matched controls. Cerebrospinal fluid (CSF) levels of interleukin-8 (IL-8), a major proinflammatory cytokine, were measured as a biomarker of intrathecal inflammation. Patients were followed up for 2 years. Clinical and imaging measures of disease progression were recorded.

Results:

High central contents of IL-8 were associated to clinical progression in subjects with RIS, and to the risk of conversion to MS in subjects with CIS. Asymptomatic intrathecal inflammation placed subjects at risk for MS conversion, even regardless lesion load. CSF IL-8 levels were higher in RR MS with high disease activity. Higher number of relapses in the first two years since diagnosis and shorter first inter-attack intervals were observed in patients with high levels of IL-8.

Conclusion:

IL-8 might provide utility in determining the presence of active intrathecal inflammation, and could be important in diagnostically undefined cases.

Progressive brain damage, synaptic reorganization and NMDA activation in a model of epileptogenic cortical dysplasia

Whether severe epilepsy could be a progressive disorder remains as yet unresolved. We previously demonstrated in a rat model of acquired focal cortical dysplasia, the methylazoxymethanol/pilocarpine - MAM/pilocarpine - rats, that the occurrence of status epilepticus (SE) and subsequent seizures fostered a pathologic process capable of modifying the morphology of cortical pyramidal neurons and NMDA receptor expression/localization. We have here extended our analysis by evaluating neocortical and hippocampal changes in MAM/pilocarpine rats at different epilepsy stages, from few days after onset up to six months of chronic epilepsy. Our findings indicate that the process triggered by SE and subsequent seizures in the malformed brain i) is steadily progressive, deeply altering neocortical and hippocampal morphology, with atrophy of neocortex and CA regions and progressive increase of granule cell layer dispersion; ii) changes dramatically the fine morphology of neurons in neocortex and hippocampus, by increasing cell size and decreasing both dendrite arborization and spine density; iii) induces reorganization of glutamatergic and GABAergic networks in both neocortex and hippocampus, favoring excitatory vs inhibitory input; iv) activates NMDA regulatory subunits. Taken together, our data indicate that, at least in experimental models of brain malformations, severe seizure activity, i.e., SE plus recurrent seizures, may lead to a widespread, steadily progressive architectural, neuronal and synaptic reorganization in the brain. They also suggest the mechanistic relevance of glutamate/NMDA hyper-activation in the seizure-related brain pathologic plasticity.

Intrinsic epileptogenicity of dysplastic cortex: converging data from experimental models and human patients

Focal cortical dysplasia (FCD) is a brain malformation associated with particularly severe drug-resistant epilepsy that often requires surgery for seizure control. The molecular basis for such enhanced propensity to seizure generation in FCD is not as yet elucidated. To investigate cellular and molecular bases of epileptogenic mechanisms and possible effect of severe epilepsy on the malformed cortex we have here performed a parallel analysis of a rat model of acquired cortical dysplasia previously established in our laboratory, i.e., the methylazoxymethanol/pilocarpine (MAM-PILO) rats, and surgical samples from patients with type IIB FCD. Data from the MAM-PILO rat model and human FCD samples reveal in both conditions: (1) that status epilepticus (SE) and/or seizures can further modify the cellular and molecular settings of the malformed cortex; (2) excitation/inhibition imbalance, and dysregulation of the N-methyl-d-aspartate/ membrane-associated guanylate kinase (NMDA/MAGUK) expression; (3) activation of cell death in neurons and glia. The data therefore highlight the mechanistic relevance of glutamate/NMDA hyperactivation in FCD epileptogenesis and suggest that epilepsy is a pathologic process capable of affecting structure and function of both neurons and glia.

Long-duration epilepsy affects cell morphology and glutamatergic synapses in type IIB focal cortical dysplasia

To investigate hypothesized effects of severe epilepsy on malformed cortex, we analyzed surgical samples from eight patients with type IIB focal cortical dysplasia (FCD) in comparison with samples from nine non-dysplastic controls. We investigated, using stereological quantification methods, where appropriate, dysplastic neurons, neuronal density, balloon cells, glia, glutamatergic synaptic input, and the expression of N-methyl-D-aspartate (NMDA) receptor subunits and associated membrane-associated guanylate kinase (MAGUK). In all FCD patients, the dysplastic areas giving rise to epileptic discharges were characterized by larger dysmorphic neurons, reduced neuronal density, and increased glutamatergic inputs, compared to adjacent areas with normal cytology. The duration of epilepsy was found to correlate directly (a) with dysmorphic neuron size, (b) reduced neuronal cell density, and (c) extent of reactive gliosis in epileptogenic/dysplastic areas. Consistent with increased glutamatergic input, western blot revealed that NMDA regulatory subunits and related MAGUK proteins were up-regulated in epileptogenic/dysplastic areas of all FCD patients examined. Taken together, these results support the hypothesis that epilepsy itself alters morphology-and probably also function-in the malformed epileptic brain. They also suggest that glutamate/NMDA/MAGUK dysregulation might be the intracellular trigger that modifies brain morphology and induces cell death.

Spinal muscular atrophy pathogenic mutations impair the axonogenic properties of axonal-survival of motor neuron

The axonal survival of motor neuron (a-SMN) protein is a truncated isoform of SMN1, the spinal muscular atrophy (SMA) disease gene. a-SMN is selectively localized in axons and endowed with remarkable axonogenic properties. At present, the role of a-SMN in SMA is unknown. As a first step to verify a link between a-SMN and SMA, we investigated by means of over-expression experiments in neuroblastoma-spinal cord hybrid cell line (NSC34) whether SMA pathogenic mutations located in the N-terminal part of the protein affected a-SMN function. We demonstrated here that either SMN1 missense mutations or small intragenic re-arrangements located in the Tudor domain consistently altered the a-SMN capability of inducing axonal elongation in vitro. Mutated human a-SMN proteins determined in almost all NSC34 motor neurons the growth of short axons with prominent morphologic abnormalities. Our data indicate that the Tudor domain is critical in dictating a-SMN function possibly because it is an association domain for proteins involved in axon growth. They also indicate that Tudor domain mutations are functionally relevant not only for FL-SMN but also for a-SMN, raising the possibility that also a-SMN loss of function may contribute to the pathogenic steps leading to SMA.

Status epilepticus-induced pathologic plasticity in a rat model of focal cortical dysplasia

We have generated an experimental 'double-hit' model of chronic epilepsy to recapitulate the co-existence of abnormal cortical structure and frequently recurrent seizures as observed in human focal cortical dysplasia. We induced cortical malformations by exposing rats prenatally to methylazoxymethanol acetate and triggered status epilepticus and recurrent seizures in adult methylazoxymethanol acetate rats with pilocarpine. We studied the course of epilepsy and the long-term morphologic and molecular changes induced by the occurrence of status epilepticus and subsequent chronic epilepsy in the malformed methylazoxymethanol acetate exposed brain. Behavioural and electroencephalographic analyses showed that methylazoxymethanol acetate pilocarpine rats develop more severe epilepsy than naïve rats. Morphologic and molecular analyses demonstrated that status epilepticus and subsequent seizures, but not pilocarpine treatment per se, was capable of affecting both cortical architectural and N-methyl-D-aspartate receptor abnormalities induced by methylazoxymethanol acetate. In particular, cortical thickness was further decreased and N-methyl-D-aspartate regulatory subunits were recruited at the postsynaptic membrane. In addition, methylazoxymethanol acetate pilocarpine rats showed abnormally large cortical pyramidal neurons with neurofilament over-expression. These neurons bear similarities to the hypertrophic/dysmorphic pyramidal neurons observed in acquired human focal cortical dysplasia. These data show that status epilepticus sets in motion a pathological process capable of significantly changing the cellular and molecular features of pre-existing experimental cortical malformations. They suggest that seizure recurrence in human focal cortical dysplasia might be an additional factor in establishing a pathological circuitry that favours chronic neuronal hyperexcitability.

Mutations in the mitochondrial protease gene AFG3L2 cause dominant hereditary ataxia SCA28

Autosomal dominant spinocerebellar ataxias (SCAs) are genetically heterogeneous neurological disorders characterized by cerebellar dysfunction mostly due to Purkinje cell degeneration. Here we show that AFG3L2 mutations cause SCA type 28. Along with paraplegin, which causes recessive spastic paraplegia, AFG3L2 is a component of the conserved m-AAA metalloprotease complex involved in the maintenance of the mitochondrial proteome. We identified heterozygous missense mutations in five unrelated SCA families and found that AFG3L2 is highly and selectively expressed in human cerebellar Purkinje cells. m-AAA-deficient yeast cells expressing human mutated AFG3L2 homocomplex show respiratory deficiency, proteolytic impairment and deficiency of respiratory chain complex IV. Structure homology modeling indicates that the mutations may affect AFG3L2 substrate handling. This work identifies AFG3L2 as a novel cause of dominant neurodegenerative disease and indicates a previously unknown role for this component of the mitochondrial protein quality control machinery in protecting the human cerebellum against neurodegeneration.

Early cerebrovascular and parenchymal events following prenatal exposure to the putative neurotoxin methylazoxymethanol

One of the most common causes of neurological disabilities are malformations of cortical development (MCD). A useful animal model of MCD consists of prenatal exposure to methylazoxymethanol (MAM), resulting in a postnatal phenotype characterized by cytological aberrations reminiscent of human MCD. Although postnatal effects of MAM are likely a consequence of prenatal events, little is known on how the developing brain reacts to MAM. General assumption is the effects of prenatally administered MAM are short lived (24 h) and neuroblast-specific. MAM persisted for several days after exposure in utero in both maternal serum and fetal brain, but at levels lower than predicted by a neurotoxic action. MAM levels and time course were consistent with a different mechanism of indirect neuronal toxicity. The most prominent acute effects of MAM were cortical swelling associated with mild cortical disorganization and neurodegeneration occurring in absence of massive neuronal cell death. Delayed or aborted vasculogenesis was demonstrated by MAM's ability to hinder vessel formation. In vitro, MAM reduced synthesis and release of VEGF by endothelial cells. Decreased expression of VEGF, AQP1, and lectin-B was consistent with a vascular target in prenatal brain. The effects of MAM on cerebral blood vessels persisted postnatally, as indicated by capillary hypodensity in heterotopic areas of adult rat brain. In conclusion, these results show that MAM does not act only as a neurotoxin per se, but may additionally cause a short-lived toxic effect secondary to cerebrovascular dysfunction, possibly due to a direct anti-angiogenic effect of MAM itself.

NMDA Receptor Composition Differs Among Anatomically Diverse Malformations of Cortical Development

Altered excitatory synaptic activity is likely a key factor in the neuronal hyperexcitability of developmental cerebral malformations. Using a combined morphologic and molecular approach, we investigated the NMDA receptor and related protein composition in human epileptic patients affected by periventricular nodular heterotopia, subcortical band heterotopia, or focal cortical dysplasia. Our results indicate that expression levels of specific NMDA receptor subunits are altered in both cerebral heterotopia and cortical dysplasia. A selective increase in the NR2B subunit was present in all cortical dysplasia, whereas the expression level of NR2A and NR2B subunits was significantly downregulated in all patients with heterotopia. NR2B upregulation in cortical dysplasia was greater in the total homogenate than the postsynaptic membrane fraction, suggesting that mechanisms other than increased ionic influx through the postsynaptic membrane may sustain hyperexcitability in dysplastic neurons. In cerebral heterotopia, the NR2A and NR2B downregulation was accompanied by less evident reduction of the SAP97 and PSD-95 proteins of the MAGUK family, thus suggesting that NMDA impairment was associated with altered molecular structure of the postsynaptic membrane. Our results demonstrate that diverse human developmental malformations are associated with different alterations of the NMDA receptor, which may contribute to the genesis of epileptic phenomena.

Electroencephalographic recordings of focal seizures in patients affected by periventricular nodular heterotopia: role of the heterotopic nodules in the genesis of epileptic discharges

Patients affected by periventricular nodular heterotopia are frequently characterized by focal drug-resistant epilepsy. To investigate the role of periventricular nodules in the genesis of seizures, we analyzed the electroencephalographic (EEG) features of focal seizures recorded by means of video-EEG in 10 patients affected by different types of periventricular nodular heterotopia and followed for prolonged periods of time at the epilepsy center of our institute. The ictal EEG recordings with surface electrodes revealed common features in all patients: all seizures originated from the brain regions where the periventricular nodular heterotopia were located; EEG patterns recorded on the leads exploring the periventricular nodular heterotopia were very similar both at the onset and immediately after the seizure's end in all patients. Our data suggest that seizures are generated by abnormal anatomic circuitries, including the heterotopic nodules and adjacent cortical areas. The major role of heterotopic neurons in the genesis and propagation of epileptic discharges must be taken into account when planning surgery for epilepsy in patients with periventricular nodular heterotopia.

NMDA receptor subunits are phosphorylated by activation of neurotrophin receptors in PSD of rat spinal cord

We have investigated the distribution of NMDA and neurotrophin receptor systems and their reciprocal interactions in post-synaptic densities (PSD) purified from spinal cord. NMDA receptor subunits, trkA and trkB, but not trkC, were present in spinal cord PSD. The incubation of PSD with BDNF and NGF induced the phosphorylation of NR2A and B subunits. This phosphorylation was counteracted by antibodies directed against the catalytic domain of trkA and trkB receptors and by genistein. These results suggest the existence of a previously unexplored cross-talk between neurotrophins and NMDA receptors in rat spinal cord neurons.

[Clinical characteristics, familial distribution and preliminary genetic data in 9 different families with "Brugada's syndrome"]

Clinical electrocardiographic evaluation and complete non-invasive assessment including nuclear magnetic resonance (NMR) are reported for 7 subjects with cardiac arrest (CA), 6 due to ventricular fibrillation (VF) and 1 to ventricular tachycardia (VT). Two more subjects, one with and one without a family history of non-resuscitated sudden death (NRSD), were included. All 9 subjects showed the typical pattern of the Brugada's syndrome (BS), characterized by incomplete right bundle branch block, ST T elevation in V1 V3. We globally evaluated 64 subjects belonging to the 9 families examined, 5 of whom were identified in Bologna, 3 in Florence and one in Parma. BS is characterized in the experience described in the present paper by a family distribution of the ECG pattern in different members. Furthermore, a family distribution of NRSD, even at a young age, was observed. Electrocardiographic features were consistent with variable degrees and aspects of the intraventricular conduction delay (ICD) and of the ST T elevation pattern. NMR has been performed so far in 23 out of 64 members examined by echo, and was normal in 17/23, with only 6 showing pathological aspects such as mild dilatation of the right ventricle, reduced thickness of the right free wall, isolated dilatation of the right ventricular infundibulum and other minor pathological aspects. Preliminary genetic screening (GS), performed on 20 members of three families, was negative for the typical genetic patterns of right ventricular dysplasia (ARVD). In six families, GS is still ongoing. Genetic screening of sodium channel pathology is in progress in the same families. In conclusion, BS has been documented in the present paper as a hereditary syndrome, both for clinical and ECG aspects, associated with CA due to VF, which required an AICD implantation, at least in symptomatic subjects. There may exist a CONGENITAL form of BS due to pathology of sodium channels, without a demonstrable structural heart disease and an ACQUIRED form of BS secondary to an initial ARVD. From the clinical point of view, a complete evaluation, including serial ECG, pharmacological testing and programmed electrical stimulation of other subjects in the families, may be important in preventing sudden death, mainly in symptomatic subjects who always require an implantable cardioverter defibrillator.

Prospective clinical evaluation and follow-up of a cohort of consecutive VT/VF patients, using a staged-care protocol, including coronary arteriography, programmed electrical stimulation and cardiac surgery

The prospective evaluation and follow-up of 39 consecutive subjects with VT/VF, 6 of whom, with cardiac arrest (CA), are reported. Patients were enrolled in a specific staged-care approach protocol, which included coronary arteriography (CAR) and ventriculography (VC), in order to exclude the need of cardiac surgery, including coronary artery bypass graft (CABG), with and without left ventricular aneurysmectomy (LVA). The protocol included inducibility of VT/VF, which was verified by programmed electrical stimulation (PES) in control conditions and after antiarrhythmic therapy (ADT), to assess persistent inducibility and mainly to verify the hemodynamic sequelae of VT. VT that showed poor hemodynamic tolerance was treated with ICD, while well-tolerated VT was treated by ADT or ablation when indicated. Furthermore, PES was obtained after surgical procedures. As a first step, the patients were assigned to receive amiodarone (AMIO) (200-400 mg/daily) in the presence of EF% < 30% or contraindication to sotalol, (Group A), or sotalol (SOT) (80-140 mg/daily) in the presence of EF > or = 31%. (Group C). Conversely, in case of recurrences, patients were assigned to receive AMIO (200-300 mg/daily) plus metoprolol (MET) (20-100 mg/daily), (Group B) or, in case of intolerance to beta-blockers, to AMIO plus mexiletine (MEX) (200 mg/daily) (Group D). The four groups were similar for the type of VA, with recurrent ventricular tachycardia (RVT) being the most frequent one. The most frequent underlying cardiac disease of VA in this study was post-AMI CAD, with a rate of over 60% in all four groups. Single- and two-vessel lesions were found at CAR in various patients in all four groups, in 5/13 (38%) in Group A, in 8/14 (57%) in Group B, in 5/7 (71%) in Group C, and in 3/5 (60%) in Group D. Cardiac surgery was performed in a similar and limited number of patients in all four groups, in 4/13 (30%) in Group A, in 4/14 (35%) in Group B, in 2/7 (28%) in Group C, and in 2/5 (40%) in Group D. In 8/39 (20.5%) of the patients who underwent CABG, there was no operative or late mortality; 4/39 (10.2%) received CABG and LVA, and two died. For the amiodarone plus metoprolol and sotalol patients only, PES showed a lower residual inducibility, in comparison to the amiodarone and amiodarone + mexiletine groups. In the entire group, 7 out of 26 (27%) were still inducibile at PES while in 19/26 (64%) of the patients, an apparently effective treatment could be found, documenting the relative usefulness of PES. Recurrence rate was the highest in the amiodarone + mexiletine group and in patients with previous CA. Our data show the potential utility and limitations of ADT, even using the most effective antiarrhythmic drugs and association of drugs, mainly because of the high recurrence rate of VT observed in the present study, even in non-inducible patients [14/39 (36%)]. In conclusion, in a prospective and staged-care approach protocol of management of VT/VF patients, only a few patients with VT/VF benefited from cardiac surgery. PES could still play a role in the evaluation of the most effective ADT. Amiodarone + metoprolol seems to be the most effective ADT in these patients. Nevertheless, a high recurrence rate was observed in this patient population, even with an aggressive protocol, in the short follow-up period of 12 +/- 8 months, confirming recent data on the superiority of ICD to ADT, in patients with frequent recurrences or hemodynamically poorly-tolerated VT. In these patients, ICD therapy should definitively be preferred to ADT.

Growth factors in pituitary tumors

Prolactin-secreting tumors are the most frequently occurring neoplasms in the human pituitary. Although the clinical syndrome associated with prolactinomas is well recognized the molecular and cellular mechanisms leading to cell transformation and development of these tumors remain elusive. In this paper we summarize recent evidence suggesting that both hypothalamic and intrapituitary defects can be involved in the development of prolactinomas. In particular alterations of the hypothalamo-pituitary dopaminergic transmission result in the dysregulation of the proliferative activity of lactotrope cells leading to tumor development. Similarly changes in the expression and activity of resident growth factors also play a role in pituitary tumorigenesis. In particular both overexpression of TGF alpha and loss of NGF production appear to be involved in the development and progression of prolactin-secreting tumors.

High vitamin A intake in early pregnancy and major malformations: a multicenter prospective controlled study

The European Network of the Teratology Information Services (ENTIS) collected and evaluated data on 423 pregnancies exposed during the first 9 weeks of gestation to a "high" dose of vitamin A (10,000 IU per day or more). Data were collected prospectively; 394 women (93.1%) were followed by telephone interview up to the first few weeks after the expected date of delivery, using standardized procedures. The presence of major structural malformations, excluding chromosomal and genetic diseases, was evaluated in 311 infants exposed to a median daily dose of vitamin A of 50,000 IU per day (range, 10,000-300,000 IU per day; interquartile range, 25,000-60,000 IU per day). Three infants with a major malformation were reported: pulmonary stenosis, stenotic anus with fistula, and bilateral inguinal hernia. No congenital malformations were reported among 120 infants exposed to more than 50,000 IU per day of vitamin A. When the birth prevalence rate of major malformations in the study group was compared with two internal control groups of infants exposed to: 1) "high" vitamin A exposure later in pregnancy, and 2) nonteratogenic agent exposures, the rate ratio was, respectively, 0.28 (CI 95% interval, 0.06, 1.23) and 0.50 (CI 95% interval, 0.14, 1.76). The studied sample did not provide evidence for an increased risk of major malformations, associated with "high" vitamin A intake during the organogenetic period, higher than 2.76 above the control reference risk of 1.91% (power 80%, alpha 0.10).

Nerve growth factor abrogates the tumorigenicity of human small cell lung cancer cell lines

Nerve growth factor (NGF) has antiproliferative and differentiating effects on adenomas of neuroendocrine origin. Cell lines derived from small-cell lung carcinoma (SCLC), a very aggressive neuroendocrine tumor, express NGF receptors. The role of NGF in the control of proliferation and progression of this carcinoma, however, has never been investigated. Chronic exposure of NCI-N-592 and GLC8 SCLC cell lines to NGF remarkably inhibited their proliferation rate both in vitro and in vivo, prevented their anchorage-independent clonal growth in soft agar, impaired their invasive capacity in vitro, and abolished their tumorigenic potential in nude mice. The proliferative response of SCLC cell lines to nicotine was also remarkably impaired by in vitro NGF treatment. Furthermore, NGF treatment activates in SCLC cell lines the expression and secretion of NGF. NGF thus reverts SCLC cell lines to a noninvasive, nontumorigenic phenotype that does not respond to nicotine and produces NGF.

Nerve growth factor suppresses the tumoral phenotype of human prolactinomas

We summarize here our data showing that various phenotypical characteristics distinguish prolactinoma cell lines obtained from responder and nonresponder patients, as defined by their responses to bromocriptine administration. Nonresponder cell lines have a higher degree of malignancy than responder cells and do not express D2 receptors for dopamine. Both cell lines express NGF receptors. Exposure of the most malignant nonresponder cell lines to NGF, both in vitro and when transplanted in vivo in nude mice, results in their differentiation into the responder phenotype reexpressing D2 receptors. Sequential administration of NGF and bromocriptine thus may be a promising therapy for patients refractory to bromocriptine.

Prospective assessment of pregnancy outcomes after first-trimester exposure to fluconazole

OBJECTIVE

Our purpose was to study prospectively the pregnancy outcome after first-trimester exposure to fluconazole, an effective antifungal agent teratogenic in animals.

STUDY DESIGN

We conducted a prospective cohort study of women who contacted three Italian teratogen information services. We compared the pregnancy outcomes of 226 women exposed to fluconazole with that of 452 women exposed to nonteratogenic agents, with use of logistic regression to control for potential confounders.

RESULTS

Among the 226 pregnancies exposed to fluconazole there were 22 miscarriages, 1 stillbirth, and 7 infants with congenital anomalies. The prevalence of these outcomes and of neonatal growth parameters and the rate of neonatal complications were similar to those in the reference group. Women in the fluconazole group had a fivefold increased occurrence of induced abortions.

CONCLUSIONS

First-trimester exposure to fluconazole does not appear to increase the prevalence of miscarriages, congenital anomalies, and low birth weight.

Severity of arrhythmias and extent of hypertrophy in hypertrophic cardiomyopathy

To evaluate the relationship between the extent of left ventricular hypertrophy and ventricular or atrial arrhythmias, 77 patients with hypertrophic cardiomyopathy underwent two-dimensional echocardiography and 24-hour Holter monitoring. Antiarrhythmic treatment was discontinued before the study. Hypertrophy was septal in 33 patients, "extensive" (i.e., involving the septum and free wall) in 38 patients, and predominantly apical in six patients. Lown grade I and II ventricular arrhythmias were detected in 37% of patients, grade III in 21%, and grade IV in 29%. Atrial extrasystoles were seen in 52% of patients and chronic atrial fibrillation in 13%. More serious ventricular arrhythmias (Lown grades III and IV) occurred significantly more frequently in patients with extensive than in those with only septal hypertrophy (22/38 vs 11/33; p less than 0.001); similarly, chronic atrial fibrillation occurred more commonly in those with extensive hypertrophy (9/38 vs 1/33; p less than 0.01). During a mean follow-up period of 2.6 years, three patients died. All had a pattern of extensive hypertrophy. Two of them had ventricular tachycardia and the third had chronic atrial fibrillation. Results of this study suggest that an echocardiographic finding of extensive hypertrophy represents a useful marker for detecting patients at increased risk for serious ventricular and atrial arrhythmias.

[Efficacy of verapamil in the prevention of ventricular fibrillation in the acute phase of myocardial infarction]

The effectiveness of verapamil in preventing ventricular fibrillation caused by coronary occlusion or reperfusion has been well demonstrated in animal studies, but these experimental data have not yet been confirmed in man. In this study we evaluated the prevalence of ventricular arrhythmias (fibrillation, sustained tachycardia and frequent extrasystoles) in patients hospitalized for myocardial infarction and treated with or without verapamil. The records of patients admitted to our Coronary Intensive Care unit during a 5-year period were analyzed retrospectively. Strict selection criteria enabled us to divide our patients into two homogeneous groups. The control group (group A) consisted of 106 patients who received only continuous infusions of heparin. The treated group (group B) comprised 89 patients who received exclusively verapamil by intravenous injections followed by continuous infusions. The prevalence of ventricular arrhythmia of all types was significantly lower in group B (22 p. 100) than in group A patients (71 p. 100; p less than 0.001). Episodes of ventricular fibrillation, in particular, were considerably less frequent in group B patients (1 p. 100) than in group A patients (13 p. 100; p less than 0.001). It would appear from these results that verapamil is highly effective in preventing death due to cardiac arrhythmia in the acute phase of myocardial infarction.

[Identification using thoracic electromapping of patients with sustained postinfarct ventricular tachycardia. Preliminary results of a new method of analysis of ST-T isoarea maps]

Recent studies have demonstrated that body surface maps (BSM) can be employed as non-invasive diagnostic tool for recognizing cardiac states at risk for repetitive ventricular arrhythmias in patients (pts) with old infarction. Our study reports preliminary results of a new method of statistical analysis of ST-T isoarea maps for identifying patients with post-infarction sustained ventricular tachycardia. 38 pts with previous myocardial infarction have been studied, 25 without and 13 with sustained ventricular tachycardia (VT). The two groups of pts did not differ significantly for age, site of infarction and ejection fraction. BSM have been recorded by means of an automated 35-channels instrument from 140 thoracic leads. For each lead ST-T deflection area has been calculated in microV.sec and taken as input variables for stepwise discriminant analysis which allowed identification of the integral values significantly discriminant (for F less than 0.15) between the two groups. Canonical analysis has been applied to identified values to obtain, by canonical coefficients, linear combination of the values for the highest correlation with the two groups of pts. To test the power of the method, the two groups of pts have been divided randomly in a learning set (17 pts without and 9 pts with VT) and a test set (8 pts without and 4 pts with VT).(ABSTRACT TRUNCATED AT 250 WORDS)

[Experimental characterization of propafenone. Hemodynamic effects]

We studied the haemodynamic effects of Propafenon in a group of 20 subjects who had a coronary arteriography and a left ventriculography. The drug was been administered in doses of 1 mg/kg b.w. i.v. in 5 minutes. The haemodynamic parameters were measured in basal conditions and after 10 and 20 minutes. The basal data and those obtained after 20 minutes were analyzed and compared statistically. Our results show that Propafenon administered acutely i.v. in therapeutic doses causes a very small depression of cardiac inotropism. The same results were obtained in subjects whose basal haemodynamic parameters were abnormal. Our data show that the drug can be used safely also in subjects with mild heart failure.

[Recording of monophasic action potentials of the right ventricle in a case of long QT and isolated alternation of the U wave]

Monophasic action potentials (MAP) of the right ventricle were recorded with suction electrodes in a case of long QTU, electrical alternans of the U wave and "torsades de pointe" by hypocalcaemia. Two electrophysiological features were observed:--a notable difference in the duration of MAPs of different zones of the right ventricle;--a change in the length and appearances of phase 3 of the longest MAPs with an inconstant bulge (delayed repolarisation) in the terminal portion of these same MAPs. These changes, which favourise focal reentry phenomena and/or reciprocal conduction are the probable explanation of the pathogenesis of episodes of "torsades de pointe". A reduction in the conductance of potassium associated or related to hypocalcaemia probably explains the second of the two changes.