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.

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.

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.

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.

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.

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.

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.

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.

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.

Digital subtraction angiography for arteriovenous malformations in stereotactic radiosurgery.

Images coming from digital subtraction angiography (DSA) are affected by a perspective distortion due to the use of image intensifiers. As a result, DSA cannot be used for the accurate definition of stereotactic coordinates. A correction method has been developed to enable the use of DSA for the radiosurgery of arteriovnous malformations. A software program and a special phantom tool were employed. The phantom is made by a computer-controlled drilling machine which makes holes in a Plexiglas plate. It has 865 calibration steel spheres with coordinates determined with a precision of 0.01 mm. A calibration image is acquired by a personal computer, and the software calculates the transformation algorithm to superimpose the image on the known positions of the phantom. This algorithm is saved and then recalled to transform the diagnostic images.

Gamma Knife radiosurgery in skull base meningiomas. Preliminary experience with 50 cases.

Gamma Knife radiosurgery was performed on 50 patients (10 males and 40 females) with skull base meningiomas (SBMs) between February 1993 and September 1995. The patients ranged in age from 25 to 78 years (mean age 56 years). The location of the tumors was anterior fossa (n = 4), sphenoorbital (n = 2), sellar region (n = 5), cavernous sinus (n = 26), petroclival (n = 12), and occipital foramen (n = 1). The tumor volume ranged from 0.6 to 20 cm3 (mean 8.6 cm3). The mean values for dose planning were edge isodose (EI) 46.7%, edge dose (ED) 18.0 Gy, maximum dose 39.8 Gy, average dose (AD) 25.4 Gy, and average number of isocentres 5.7. The patients were analyzed for five parameters: tumor volume (< 7.5 vs. > or = 7.5 cm3); EI (< 50 vs. > or = 50%); ED (< 18 vs. > or = 18 Gy); AD (< 25 vs. > or = 25 Gy), and primary versus residual or recurrent tumors. The overall frequency of tumor growth control (TGC) was 98%, with 1- and 2-year TGC rates of 97% and 100%, respectively. The most favorable neurological results were obtained with a tumor volume < 7.5 cm3 (p < 0.05), EI > or = 50% (NS), ED > or = 18 Gy (NS) and with primary SBMs (p < 0.01). A favorable TGC was demonstrated at follow-up imaging examinations when the tumor volume was > or = 7.5 cm3 (100% TGC rate), EI < 50% (100%), ED > or = 18 Gy (100%), AD > 25 Gy (100%), in both primary SBMs (100%) and residual or recurrent SBMs (96.5%). To date, only 3 (6%) of the 50 patients have presented signs of neurological worsening related to the Gamma Knife radiosurgery. While no early complications were noted, neuroradiological follow-up did show delayed transient imaging complications (3 edema and 1 radionecrosis; 8% of all patients). In conclusion, our preliminary results seem to confirm that Gamma Knife radiosurgery is an effective and safe adjuvant or a feasible alternative primary treatment in controlling or preventing SBM progression.

Gamma Knife radiosurgery for intracranial metastases: from local tumor control to increased survival.

We have analyzed a series of 225 patients with intracranial metastases (343 lesions), treated in our department by Gamma Knife radiosurgery over a 30-month period. We have used a modified Pittsburgh protocol and performed 242 procedures on 164 single/78 multiple lesions. Primary tumors were mostly carcinomas of the lung (52%) and breast (11.6%). Neuroradiological localization of the target was usually performed by stereotactic computed tomography. Magnetic resonance imaging was only used in special circumstances. Routine dose planning was assisted by three-dimensional reconstruction programs. Mean tumor volume was larger than expected (5.7 ml). Mean prescription dose and average dose were 21.1 and 29.9 Gy, respectively. Middle- and long-term results were evaluated in a subset of 152 patients (236 lesions) with adequate (> 4 months) follow-up. Mean follow-up was 53.1 weeks with 61/152 patients still living. There was a predominance of retrospectively classified 'not fully eligible cases' among the survivors, mainly because of uncontrolled primary tumor. The 1-year local tumor control rate was 88.2%. Treatment-related radiological (3.9%) and clinical (1.6%) sequelae were minimal. Overall mean survival in these patients (40 weeks) turned out to be higher than that commonly reported after conventional surgical-radiation treatments. It was encouraging that the mean survival of 'fully' eligible patients was 51 weeks. Karnofsky performance status and neurological (Order Grading) performance scores were consistently high for most of the follow-up period. Functional Independence and the Palliative Index were not far from the value of mean survival. The main cause of death remains uncontrolled systemic disease (64.8%). On the other hand, the relative incidence of intracranial tumor progression was considerably decreased. This indicated that these patients should perhaps be treated more aggressively and underlines the need for randomized trials to determine the optimal treatment.

Gamma Knife stereotactic radiosurgery for uveal melanoma: clinical results after 2 years.

We report on 36 cases of uveal melanoma treated at our center between March 1993 and September 1995. There were 16 men and 20 women, aged 57 +/- 11 years. The choroid was affected in 35 patients and the ciliary-body in 1. The same preoperative and follow-up protocol was adopted for all cases. The procedure included fixation and positioning of the eye with a retrobulbar injection of long-lasting anesthetic and two extraocular muscle sutures, application of the frame, computed tomography scan localization, dose planning and treatment with the Gamma Knife. The patients were divided into three groups. Group A: 10 patients with a follow-up of 24 +/- 4 months, treated with a high dose (surface dose 58 +/- 9 Gy, maximum dose 81 +/- 15 Gy, mean dose 66 +/- 11 Gy). Group B: 9 patients with a follow-up of 16 +/- 2 months, treated with a lower dose (surface dose 41 +/- 3 Gy, maximum dose 76 +/- 10 Gy, mean dose 53 +/- 11 Gy). Group C: 17 patients with a follow-up of 6 +/- 3 months, treated with a lower dose (surface dose 42 +/- 3 Gy, maximum dose 72 +/- 16 Gy, mean dose: 54 +/- 6 Gy). In group A, we observed marked tumor regression in 9 cases, tumor recurrence in 1 case and severe complications in 5 cases (neovascular glaucoma and/or radiation retinopathy and/or radiation optic neuropathy). In group B, significant local control of the tumor was obtained with minor complications (cotton wool spots hard exudates, intraretinal hemorrhages). In group C, to date we have observed a regression of the tumor in 7 cases and 1 severe complication (neovascular glaucoma). Our data show that uveal melanomas may be adequately controlled by a high radiosurgical dosage (50-70 Gy), though there are significant side effects. Comparable levels of local tumor control may be obtainable using lower doses (40-45 Gy) which would hopefully reduce the rate of complications. However, a longer follow-up is needed for further validation of these results.

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.

A euristic approach to the volume reconstruction of arteriovenous malformations from biplane angiography.

Three-dimensional (3D) volume reconstruction is easily feasible with axial, coronal or sagittal CT and MRI scans. On the other hand, radiosurgical treatment of arteriovenous malformations (AVMs) 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 volume reconstruction starting from two stereotactic orthogonal projections. This has been achieved using a euristic approach which has been widely adopted in the artificial intelligence domain. Tests on phantoms of different complexity have shown excellent results. The importance of the algorithm is considerable. Firstly, it allows calculations of complex structures far removed from a regular ellipsoid. Secondly, it permits shape recovery. Thirdly, it provides AVM visualization on axial planes.