Calcineurin and GSK-3 inhibition sensitizes T-cell acute lymphoblastic leukemia cells to apoptosis through X-linked inhibitor of apoptosis protein degradation.

The calcineurin (Cn)-nuclear factor of activated T cells signaling pathway is critically involved in many aspects of normal T-cell physiology; however, its direct implication in leukemogenesis is still ill-defined. Glycogen synthase kinase-3ß (GSK-3ß) has recently been reported to interact with Cn in neuronal cells and is implicated in MLL leukemia. Our biochemical studies clearly demonstrated that Cn was able to interact with GSK-3ß in T-cell acute lymphoblastic leukemia (T-ALL) cells, and that this interaction was direct, leading to an increased catalytic activity of GSK-3ß, possibly through autophosphorylation of Y216. Sensitivity to GSK-3 inhibitor treatment correlated with altered GSK-3ß phosphorylation and was more prominent in T-ALL with Pre/Pro immunophenotype. In addition, dual Cn and GSK-3 inhibitor treatment in T-ALL cells promoted sensitization to apoptosis through proteasomal degradation of X-linked inhibitor of apoptosis protein (XIAP). Consistently, resistance to drug treatments in primary samples was strongly associated with higher XIAP protein levels. Finally, we showed that dual Cn and GSK-3 inhibitor treatment in vitro and in vivo is effective against available models of T-ALL, indicating an insofar untapped therapeutic opportunity.

Tumor outgrowth in peripheral blood mononuclear cell-injected SCID mice is not associated with early Epstein-Barr virus reactivation.

Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disease develops in severe combined immunodeficient (SCID) mice inoculated with peripheral blood mononuclear cells (PBMC) from EBV(+) individuals (SCID/hu mice). In this study, we investigated the contribution of EBV reactivation and de novo infection of B lymphocytes to tumor outgrowth in SCID/hu mice. Evaluation of BZLF-1, an early EBV activation transcript, in cells recovered from the mouse peritoneal cavity within 16 days following PBMC transfer did not reveal EBV reactivation, while BZLF-1 expression was only detected in tumor masses or in vitro established lymphoblastoid cell lines. To confirm these data by a different strategy, we coinjected PBMC from seropositive donors with purified B cells from seronegative donors of different sex. Fluorescence in situ hydridization analysis of the resulting tumor masses disclosed that the overwhelming majority of lymphoma cells originated from the seropositive donor, implying that no substantial in vivo production and transmission of virus had occurred. Further, treatment of SCID/hu mice with ganciclovir did not prevent lymphoma development. Our results suggest that in the SCID/hu mouse, early EBV replication and secondary infection of bystander B cells does not occur, and that the direct outgrowth of the transformed B lymphocytes present within the PBMC inoculum is the predominant mechanism, which leads to lymphoma generation in this experimental model.

Stereotactic brain biopsy in human immunodeficiency virus-infected patients.

OBJECTIVE: To evaluate prospectively the diagnostic efficacy and safety of stereotactic brain biopsy and its impact on treatment, outcome, and survival in human immunodeficiency virus-infected patients with focal brain lesions. METHODS: Computed tomography-guided stereotactic brain biopsy was performed in 26 patients, of whom 17 failed to respond to a 2- to 3-week anti- Toxoplasma regimen. Exclusion criteria for biopsy were overt acquired immunodeficiency syndrome for 2 years or longer, Karnofsky score less than 50, and severe coagulopathies. RESULTS: A definitive diagnosis was obtained in 24 patients (92%), of whom 12 (46%) had primary brain lymphoma, six (23%) had progressive multifocal leukoencephalopathy, and four (15%) had Toxoplasma encephalitis. Two thirds of contrast-enhancing lesions on computed tomography were lymphoma and three fourths of contrast-negative lesions were leukoencephalopathy. Three patients had biopsy-related cerebral hemorrhages (morbidity, 11.5%). Median follow-up and survival for the entire group were 24 weeks (range, 6 to 135 weeks). Twenty patients (77%) received specific therapy and 13 (50%) responded to treatment. Of 11 patients with lymphoma undergoing irradiation treatment (whole-brain radiotherapy in seven and gamma-knife treatment in four), nine (82%) had clinical and radiologic response, with a median survival of 34 weeks (range, 13 to 57 weeks). CONCLUSIONS: Stereotactic brain biopsy has high diagnostic efficacy and clinical benefit in carefully selected human immunodeficiency virus-infected patients. The procedure should be performed essentially in patients with contrast-enhancing lesions on computed tomography who have a high frequency of treatable cerebral diseases.

Shape recovery and volume calculation from biplane angiography in the stereotactic radiosurgical treatment of arteriovenous malformations.

PURPOSE: A model for calculating the three-dimensional volume of arteriovenous malformations from biplane angiography. METHODS AND MATERIAL: Three-dimensional (3D) volume reconstruction is easily feasible with axial, coronal, or sagittal computer tomography (CT) and nuclear magnetic resonance (NMR) scans. On the other hand, radiosurgical treatment of arteriovenous malformations (AVM) is exclusively based on two orthogonal stereotactic projections, obtained with angiographic procedures. Most commonly, AVM volumes have been calculated by assimilating the nidus volume to a prolate ellipsoid. We present an algorithm dedicated to 3D structure reconstruction starting from two orthogonal stereotactic projections. This has been achieved using a heuristic approach, which has been widely adopted in the artificial intelligence domain. RESULTS: Tests on phantom of different complexity have shown excellent results. CONCLUSION: The importance of the algorithm is considerable. As a matter of fact: (a) it allows calculations of complex structures far away from regular ellipsoid; (b) it permits shape recovery; (c) it provides AVM visualization on axial planes.

Preoperative embolization of arteriovenous malformations with polylene threads: techniques with wing microcatheter and pathologic results.

The technique with a wing microcatheter system and the pathologic aspects of 11 cerebral arteriovenous malformations (AVMs) surgically resected after embolization with polylene threads are reported. Embolization was performed once in eight patients and twice in three patients. Resected AVMs were submitted both to routine hematoxylineosin examination and to immunohistochemical workup in order to detect the type of immunologic response to thread emboli. In nine cases, 50% or more of the nidus was obliterated by the embolization. After embolization two patients developed reversible neurologic deficits. Pathologic specimens of resected AVMs demonstrated no vascular necrosis; however, a moderate inflammatory response could be seen, characterized by the presence of both mononuclear cells and foreign-body giant cells, associated with the absence of polymorphonuclear infiltrates. A granulomatous fibrotic process was identified that was present from the first month after embolization. Immunohistochemistry indicated that the immunologic response to thread emboli was cell-mediated, not humoral. Embolization with the wing microcatheter with the use of polylene threads proved to be a safe and efficient system of embolization, as a preoperative procedure. Polylene threads are a nontoxic and biocompatible material that can be used as an embolic agent for brain AVMs.

Double-blind comparison of safety and efficacy of iomeprol and iopamidol in carotid digital subtraction angiography.

Iomeprol is a nonionic monomer which provides injectable formulations with the lowest osmolalities and the lowest viscosities among the currently available low-osmolar radiographic contrast agents of the same category. These favourable physico-chemical characteristics, together with high water solubility and low molecular toxicity, make this agent particularly suitable for carotid angiography, a procedure in which contrast-induced blood-brain barrier damage is maximal. This single-centre, randomised, double-blind, parallel-group study aimed at comparing the safety, tolerance and efficacy of 200 mgI/ml solutions of iomeprol and iopamidol in 100 consenting adult inpatients undergoing carotid intra-arterial digital subtraction angiography (IA-DSA). Both agents appeared to be safe and well tolerated. Only minor and transient adverse events occurred throughout the study. Electroencephalographic and neurological examinations performed pre- and post-contrast showed no abnormality induced by the test compounds. Vessel opacification was good or excellent in the vast majority of technically adequate examinations. Information provided by the angiographic examination was useful for subsequent patient management in almost all cases. It is concluded that iomeprol-200 and iopamidol-200 are safe and effective contrast media when used for carotid IA-DSA, an examination which proves useful not only for the diagnosis of vascular lesions, but also to best direct the management of patients scheduled for surgery of intracranial tumors.

Spontaneous arterio-venous fistulae of the vertebral artery. Diagnostic and therapeutic considerations.

Spontaneous arterio-venous fistulae of the vertebral artery are rare. These lesions mainly affect the upper cervical area, and are usually asymptomatic, or may present as small, often pulsatile, cervical masses with vascular murmurs. The authors report on two cases in which the presumptive diagnosis, suggested by venous digital subtraction angiography, was then confirmed by selective angiography. In both cases an intravascular approach with detachable balloons and particulate substances was carried out, with good anatomical and functional results. Problems related to diagnosis, pathophysiology of symptoms, indications for treatment and embolization techniques are discussed.

Venous digital subtraction angiography in the evaluation of renovascular hypertension.

The study of renovascular hypertension (R.V.H.) presently requires multiple non invasive examinations in order to select between patients with R.V.H. or other kind of hypertension, before resorting to angiography. The use of venous digital subtraction angiography (V.D.S.A.) may change this diagnostic flow-chart. For this purpose, 100 patients with clinical and laboratory data suspect of R.V.H. underwent V.D.S.A. Compared to angiography, V.D.S.A. showed a 100% sensitivity and 93% specificity. Since the sensitivity and specificity of the non invasive techniques vs. V.D.S.A. in the same series was always lower, V.D.S.A. may be proposed as the first examination in the study of R.V.H. The arterial route for D.S.A. is generally not required for diagnostic purposes.

Stereotactic radiosurgery for the treatment of arteriovenous malformations in childhood.

BACKGROUND: The main techniques and results in stereotactic radiosurgical treatment of endocranial AVM's are described and compared. The authors also report their preliminary experience in the treatment of 6 consecutive pediatric patients with intracerebral vascular malformations using gamma knife (GK) radiosurgery. METHODS: The various stereotactic radiosurgery methods currently used (charged-particle beam, modified linear accelerator, and GK) are described. At the Department of Neurosurgery in Verona, from February 1993 to February 1996, stereotactic GK radiosurgery was performed on 721 patients, including 20 of pediatric age (3%). Of the 78 AVMs, 7 (9%) were diagnosed in children. One patient was lost at follow-up. Among the remaining 6 children, there were 3 males and 3 females with a mean age of 12.3 years (range, 5-16 years). Treatment general anesthesia was needed only in 1 case. The AVM volume was always less than 10 cc. After completion of the procedure, children were discharged from the hospital the following day. RESULTS: The follow-up period ranged from 4 months to 29 months (median 18.8 months). The angiographic confirmed total obliteration is used as the end point of an AVM treated radiosurgically, and usually requires 2 to 3 years. All the patients are alive; four of the treated children are neurologically normal and one patient has clinically improved to a normal neurological status. The sixth patient has fixed neurological deficits that existed prior to treatment. Among the three cases with a follow-up period of over 2 years, complete obliteration has been angiographically confirmed in 2 patients and subtotal in 1 patient. In the three remaining patients with follow-up periods less than 2 years, serial MR images suggest subtotal obliteration in 2 cases and no significant change in one patient who had undergone treatment within the current year. To date, neither persistent GK radiosurgery-related complications nor bleeding following stereotactic radiosurgery has been described. CONCLUSIONS: The review of literature and our preliminary results suggest that also in children, as in adults, the use of stereotactically delivered irradiation represents a safe and effective technique obtaining complete obliteration of AVMs previously considered surgically inaccessible due to their location and poor response to resection and/or embolization.

Endovascular treatment of pial AVMs: technical options, indications and limits in pediatric age patients.

Our study group consisted of 29 patients who underwent endovascular treatment for the presence of pial AVMs. The patients were treated with various embolization methods including "-free flow" embolization (2 cases); embolization with suture threads (2 mm long micro-emboli: 17 cases) and embolization with acrylic glue (10 cases). There were significant angio-architectural and AVM location differences between the pediatric and the adult patient groups. In pediatric patients, the more frequent AVMs were of the mono or few-pedunculated type, then simple direct fistulas and high-flow fistulous-plexiform AVMs and giant infra-tentorial or deep-seated malformations. In mono or few-pedunculated AVMs, the elected treatment was acrylic glue followed by radio-surgery achieving definitive cure in 3 cases. In direct AVFs and elevated flow AVMs, embolization with suture and acrylic glue offered definitive results. Treatment for infra-tentorial and deep-seated AVMs presented the greatest difficulty in pediatric patients. In two of them, embolization with glue enabled radiosurgery (giant cerebellar AVMs). Our experience did not confirm that current endovascular techniques provide definitive treatment in extensive, deep-seated AVMs. Each treatment, in children more so than in adults, requires a risk/benefit evaluation of the method taking into account the natural history data.

Computerized tomography and magnetic resonance guided stereotactic brain biopsy in nonimmunocompromised and AIDS patients.

BACKGROUND: The utility of stereotactic brain biopsy (SBB) in AIDS patients still remains controversial. The authors investigated SBB-related diagnostic accuracy, complications, and postoperative sequelae in nonimmunocompromised (NIC) patients and AIDS patients. The role of bioptic yield in treatment planning was also studied in AIDS patients. METHODS: From 1990-95, 200 computerized tomography (CT) or magnetic resonance imaging (MRI)-guided SBBs were performed in our Department; 172 bioptic procedures were performed in NIC patients (169), and 28 SBBs in AIDS patients (27). The statistical significance was evaluated using the Fisher exact t-test. RESULTS: SBB accuracy was very high in both NIC (94.8%) and AIDS (92.9%) patients. Statistical analysis indicated nonsignificant (NS) differences between the two study groups (P > 0.05). Diagnostic yield resulted higher in contrast-enhancing (CE) brain lesions (98.6% in NIC and 95.0% in AIDS patients; P > 0.05; NS), than in non-CE lesions (74.1% in NIC and 87.5% in AIDS patients; P > 0.05; NS). The overall complication rate was similar in both groups (17.2% in NIC and 14.8% in AIDS patients, P > 0.05, NS). The most frequent complication was hemorrhage, with statistically negligible differences between the two study groups (P > 0.05). The frequency of complications involving minor/major morbidity or mortality was very low in NIC (5.9%, 0.6%, and 2.4%, respectively), and in AIDS (3.7%, 7.4%, and 0.0%, respectively) patients. Regarding the therapeutic impact of bioptic diagnosis for neuro-AIDS patients, the preoperative treatment attitude was modified in 23/27 cases (85.2%), and the empiric anti-toxoplasmosis regimen was changed or withdrawn in 17/21 patients (81.0%). CONCLUSION: Our experience demonstrated SBB to be an accurate, manageable, and reasonably safe diagnostic tool in both NIC and AIDS patients. These results suggest also that timely SBB indication in selected AIDS patients, reaching an early diagnosis, may on one side prevent unnecessary and potentially toxic empiric therapeutic regimens, and on the other address the appropriate treatment, thereby improving length and quality of life in such patients.

[Role of digital intravenous angiography in the study of reversible cerebral ischemia]. / Le rôle de l'angiographie numérique par voie intra-veineuse dans l'étude de l'ischémie cérébrale régressive.

The brachiocephalic, carotid, vertebral and intra-cranial vessels of 497 patients presenting reversible ischemic attacks (R.I.A.) were evaluated with venous digital subtraction angiography (V.D.S.A.). Alterations of the vascular wall were observed in 289/497 (58.2%) patients, of whom 60% presented multiple locations (539 lesions): obstruction (12%), stenosis greater than 50% (29%), stenosis less than 50% (49.8%), kinking (9%), aneurysm (0.2%). An ulcerating arteriosclerotic plaque was observed in 24.6% of the stenoses less than 50% and in 48% of the stenoses greater than 50%. The incidence of vascular lesions was higher (p less than 0.01) in patients with multiple R.I.A. (66.6%) than in those with one isolated R.I.A. (55.6%). Among the patients (207/497) studied also with cerebral computed tomography (C.T.) no relationship could be defined between the extra-cranial vascular lesions demonstrated by V.D.S.A. and the cerebral alterations shown by C.T. Among the patients (64/497) studied also with high frequency ultrasonography (U.S.), the lesion shown by V.D.S.A. could be also demonstrated by U.S. in 84.8% of cases. The personal flow-chart in the study of R.I.A. is described emphasizing the primary role played by V.D.S.A. as well as the complementary role of the other techniques, both non invasive (U.S., C.T.) and invasive (conventional or digital subtraction angiography).

Tumors of the pineal region.

The role played by neuroradiologic examinations in the diagnosis of neoformations of the pineal region is considered. Results of reports of literature are compared with the personal experience (40 patients) to draw possible significant conclusions for the diagnosis of the oncological type. First, intrinsic pineal lesions should be separated from those of adjacent structures. Reliable discriminating parameters useful in the differential diagnosis are represented by sex and age. Diagnosis based on biochemistry with markers was shown not to be univocal. A further separation can be based on CT and MRI findings. In particular, teratomas appear as solid tumors with calcification and fat. The latter is depicted on MRI even if minimal. To the contrary, germinomas do not contain fat and are markedly enhancing. Microcysts seem to be more common in tumors originating from parenchymal pineal cells. A reliable differential diagnosis is however possible only for small-sized lesions where identification of the anatomical structure of origin is easier.

Updates in the determination of brain death.

The concept of brain death must be accurately determined and defined, especially in the light of the latest legislation on brain blood flow measurements.

Operative classification of brain arteriovenous malformation. Part two: validation.

SUMMARY: The most important issue when dealing with a patient with a brain AVM is the decision whether to treat or not. Only after this decision has been made, taking into consideration a number of factors depending on both the patient and the specific type of AVM, can the best option for treatment be chosen. An operative classification of brain AVMs, previously adopted in the Department of Neuroradiology and Neurosurgery of Verona (Italy) and published in this journal, was subjected to validation in a consecutive group of 104 patients clinically followed for at least three years after completion of treatment. This classification, slightly modified from the original version concerning the importance of some specific items, allowed us to assess the indication to treat in each case, whatever type of treatment was offered to the patient.

Replication patterns of human X isochromosomes by high-resolution banding.

The DNA replication patterns of eight cases of X isochromosomes, five idic(X) and three i(Xq), were studied. R-banded prometaphases and metaphases from lymphocyte cultures after synchronization with methotrexate and incorporation of 5-bromodeoxyuridine were analyzed. No significant differences in the frequency of metaphases with symmetric and asymmetric replication patterns between dicentric and monocentric isochromosomes were found. Furthermore the distribution of the frequencies of R-positive bands was similar and comparable to that of the normal late-replicating X. Our data suggest that the DNA replication pattern of Xq isochromosomes is not correlated with the mechanism of their origin.

Agenesis of the corpus callosum with Probst bundles owing to haploinsufficiency for a gene in an 8 cM region of 6q25.

Agenesis of the corpus callosum (ACC) is a relatively common brain abnormality resulting from developmental defects either limited to the structures leading to the proper formation of the corpus callosum or involving the embryo forebrain more generally. ACC is genetically heterogeneous with autosomal dominant, autosomal recessive, and X linked inheritance and has also been reported in subjects with aneuploidies involving several chromosomes. Among them, distal 6q deletions have been consistently reported in association with ACC, suggesting that there is a gene in the deleted region whose haploinsufficiency impairs normal corpus callosum development. We have studied a child with ACC with Probst bundles and a deletion at 6q25 of about 8 cM, from D6S1496 to D6S437. Probst bundles are the axons that should have formed the corpus callosum but, unable to cross the midline owing to absence of the massa commissuralis, they run longitudinally along the medial walls of the lateral ventricles from the frontal to the occipital lobes. Thus, their presence suggests that a gene located in the 6q deleted region is specifically involved in the formation of the massa commissuralis and that its haploinsufficiency leads to primary ACC.