Mario Zavanone

Proliferation of Transformed Somatotroph Cells Related to Low or Absent Expression of Protein Kinase A Regulatory Subunit 1A Protein

The two regulatory subunits (R1 and R2) of protein kinase A (PKA) are differentially expressed in cancer cell lines and exert diverse roles in growth control. Recently, mutations of the PKA regulatory subunit 1A gene (PRKAR1A) have been identified in patients with Carney complex. The aim of this study was to evaluate the expression of the PKA regulatory subunits R1A, R2A, and R2B in a series of 30 pituitary adenomas and the effects of subunit activation on cell proliferation. In these tumors, neither mutation of PRKAR1A nor loss of heterozygosity was identified. By real-time PCR, mRNA of the three subunits was detected in all of the tumors, R1A being the most represented in the majority of samples. By contrast, immunohistochemistry documented low or absent R1A levels in all tumors, whereas R2A and R2B were highly expressed, thus resulting in an unbalanced R1/R2 ratio. The low levels of R1A were, at least in part, due to proteasome-mediated degradation. The effect of the R1/R2 ratio on proliferation was assessed in GH3 cells, which showed a similar unbalanced pattern of R subunits expression, and in growth hormone-secreting adenomas. The R2-selective cAMP analog 8-Cl cAMP and R1A RNA silencing, stimulated cell proliferation and increased Cyclin D1 expression, respectively, in human and rat adenomatous somatotrophs. These data show that a low R1/R2 ratio promoted proliferation of transformed somatotrophs and are consistent with the Carney complex model in which R1A inactivating mutations further unbalance this ratio in favor of R2 subunits. These results suggest that low expression of R1A protein may favor cAMP-dependent proliferation of transformed somatotrophs.

Ghrelin and adiponectin in patients with Cushing's disease before and after successful transsphenoidal surgery

background  Ghrelin, an endogenous ligand of the GH secretagogue receptor that exerts orexigenic activity, is negatively correlated with body mass index (BMI) and insulin resistance. Conversely, low levels of adiponectin (ApN), a circulating adipocytokine with antidiabetic, antiatherogenic and anti‐inflammatory properties, have been found in several insulin‐resistant conditions. Although Cushings syndrome causes several metabolic and hormonal changes leading to insulin resistance and central obesity, few data concerning the impact of glucocorticoid excess on ghrelin and ApN levels are so far available.

The long pentraxin PTX3 as a correlate of cancer-related inflammation and prognosis of malignancy in gliomas

Inflammation is a component of glioma microenvironment. PTX3 is a component of the humoral arm of innate immunity and a candidate marker of inflammation. In the present study we assessed the expression of PTX3 in gliomas by immunohistochemistry. PTX3 expression differed across low and high-grade tumors based on histopathological diagnosis and clinical severity, positively correlating with tumor grade and severity. In a multivariate logistic regression model, only the PTX3 score was significantly associated with the presence of a high-grade tumor. Thus, PTX3 may represent a new marker of cancer-related inflammation and glioma malignancy.

Stereotactically guided endoscopy for the treatment of arachnoid cysts

Arachnoid cysts are well known to the neurosurgeon, and the evolution of their surgical treatment has followed technological advances in neurosurgical procedures and techniques. With the recent mastering of neuroendoscopy by the neurosurgeons, it is becoming the modality of choice for the treatment of arachnoid cysts. A neonate harboring a middle parasagittal arachnoid cyst benefited from stereotactically guided endoscopy. We report this case because of its peculiarities and introduce technical details about the procedure which are not found in the literature.

Isolated cervical juvenile xanthogranuloma in childhood.

Study Design. This is a report of an exceptional case of isolated cervical juvenile xanthogranuloma in a child. Objectives. This case report draws attention to the fact that isolated xanthogranuloma of the central nervous system should be considered among possible diagnosis of subdural extramedullary spinal masses in children and young adults. Summary and Background Data. Isolated juvenile xanthogranuloma of the central nervous system is extremely rare. When located in the spinal canal it behaves like any extramedullary mass-occupying lesion. MRI depicts the tumor’s association with adjacent structures. In cases in which a subtotal surgical removal was possible, radiotherapy has been indicated. Methods. A three-year-old girl presented severe pain in the right shoulder and spastic tetraparesis. The MRI showed an intradural extramedullary mass homogeneously enhancing after DTPA-gadolinium infusion. Complete surgical removal of the tumor was performed through open-door laminoplasty. Results. The child was pain free immediately after the surgical removal of the tumor. A gradual complete recovery of the neurologic deficits followed. Open-door laminoplasty provided sufficient operative space, and it minimized the impact on the growing spinal column. Conclusions. Isolated juvenile xanthogranuloma does not show any predilections of localization inside the central nervous system. Both intracranial and spinal juvenile xanthogranulomas appear isointense in MRI and enhance homogeneously with gadolinium. Whenever possible, total surgical removal alone seems to be curative. Otherwise, a subtotal removal of the tumor might be followed by radiotherapy. Immunohistochemical tests ensure the diagnosis.

Human glioma tumors express high levels of the chemokine receptor CX3CR1

The chemokine receptor CX3CR1 and its cognate ligand CX3CL1 (also known as fractalkine), are involved in central nervous system pathophysiology, in particular, in the cross-talk between neurons and microglia. It was therefore important to investigate the expression of CX3CR1 in gliomas, the most frequently occurring, malignant brain tumors. In a consecutive series of 70 patients with primary, central nervous glial tumors, CX3CR1 was highly expressed in tumor cells as assessed by RT-PCR mRNA and protein levels, and by immunohistochemistry, while the corresponding normal cells were negative. Receptor immuno-positivity did not correlate with histology, grade, chromosomal (1p,19q) deletion, or with methylation of the DNA repair gene promoter MGMT (O6-methylguanine-DNA methyltransferase). Thus, CX3CR1 expression is a frequent event in gliomas, irrespective of tumor classification and clinical severity. The molecular basis underlying CX3CR1 up-regulation and its functional biological significance remain to be determined.

Schilder's disease: non-invasive diagnosis? :A case report and review.

Schilder’s disease, or myelinoclastic diffuse sclerosis, is a rare disorder characterised by an inflammatory white matter plaque of demyelination. Clinical signs and symptoms might be atypical for early multiple sclerosis and at imaging the lesion is easily taken for a brain tumour. Regardless of the use of Poser’s criteria for clinical diagnosis of Schilder’s disease proposed in 1986, diagnostic difficulties are still present, as evidenced by the many reported cases in the English literature revised (Pubmed indexed, period 1998–2008). It clearly emerges that neuroradiological features, observable in additional magnetic resonance sequences are crucial, besides the consideration of Poser’s criteria, in differentiating between demyelinating lesions and brain tumours. A 29-year-old female patient is presented, where a careful evaluation of both the clinical and radiological features, which might have been at a first glance misleadingly suggestive for a brain tumour, allowed non-invasive diagnosis of Schilder’s disease.

Gene expression profile analysis of human mesenchymal stem cells from herniated and degenerated intervertebral discs reveals different expression of osteopontin.

Gene expression analysis provides an effective methodology to identify clinically relevant genes implicated in intervertebral disc (IVD) pathology. The analysis of gene profile in mesenchymal stem cells (MSCs) from human herniated IVD (H-IVD) and degenerated IVD (D-IVD) has not yet been investigated. We present in this study a characterization of MSCs isolated from clinically categorized H-IVD and D-IVD disc samples. H-IVD-MSCs and D-IVD-MSCs showed multipotent mesenchymal differentiation ability, expressing positivity for adipogenic, osteogenic, and chondrogenic markers with an immunophenotypical profile representative of MSCs. FACS analyses revealed a higher expression of CD44 in D-IVD-MSCs compared to H-IVD-MSCs. Gene expression profile revealed that most genes under investigation displayed large variations and were not significantly different in the two types of analyzed IVD-MSCs. Conversely, the gene expression of osteopontin (OPN), a protein involved in bone matrix mineralization and extracellular matrix destruction, was found markedly increased (more than 400-fold) in D-IVD-MSCs compared to H-IVD-MSCs. Moreover, the OPN protein expression was detectable only in D-IVD-MSCs, and its levels were directly related with D-IVD severity. These findings suggest that an abnormal expression of OPN in D-IVD-MSCs occurs and plays a pivotal role in the pathophysiological process of human disc degeneration. We speculate that the regulation of the OPN pathway might be a therapeutic target to counteract disc degeneration.

Third Ventriculostomy in Late-onset Idiopathic Aqueductal Stenosis Treatment: A Focus on Clinical Presentation and Radiological Diagnosis

Endoscopic third ventriculostomy (ETV) is considered the gold standard treatment for obstructive hydrocephalus due to partial or complete obstruction of cerebrospinal fluid (CSF) ventricular pathways caused by mass lesions. However long-term efficacy of this procedure remains controversial as treatment of chronic adult hydrocephalus due to stenosis of Sylvian acqueduct [late-onset idiopathic aqueductal stenosis (LIAS)]. The authors describe clinical presentation, diagnostic investigations in patients affected by LIAS, and define their clinical and radiological outcome after ETV. From January 2003 to December 2008, 13 consecutive LIAS patients treated by ETV were retrospectively reviewed. Pre- and post-operative clinical and radiological findings, including conventional and phase-contrast (PC) cine magnetic resonance imaging (MRI) were investigated. ETV was successfully performed in all patients. Patients neurological condition improved. No one required a second ETV procedure or shunt implantation. Clinical and radiological results reveal a satisfactory outcome of LIAS patients treated by ETV. At follow-up a clinical improvement could be demonstrated in all cases. Selection criteria of LIAS patients seem to be crucial to obtain satisfactory and long-lasting results. Even in elderly patients with chronic hydrocephalus, ETV can be considered the treatment of choice.

Microscopic versus endoscopic transsphenoidal surgery for pituitary adenoma: Analysis of surgical safety in 221 consecutive patients

• Arachnoid cyst of the fallopian canal should be suspected and sought in all cases of CSF leak or bacterial meningitis (especially Streptococcus pneumonia, Haemophilus influenzae) in overweight middleaged women without any osteo-meningeal breach identified on the tegmen tympani. • A combination of CT scan and MRI allows the diagnosis of arachnoid cyst of the fallopian canal, can be used to rule out other confounding diagnoses and provides all essential preoperative information. • No systematic surgery is needed for arachnoid cysts of the fallopian canal that have no CSF leak. • When a leak from an arachnoid cyst is identified or when it is associated with a history of meningitis, surgery is needed; a middle ear approach allows minimal invasion with good long-term results. • The idiopathic intracranial hypertension syndrome should be sought in cases of arachnoid cyst of the fallopian canal by performing ophthalmological examination and cerebral MRI. References