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G Pendl

Publications and source records attributed to G Pendl.

At least 55 records · Page 3Linked to original sources
PubMed1997

The binding of T cell-expressed P-selectin glycoprotein ligand-1 to E- and P-selectin is differentially regulated.

The HECA452 carbohydrate epitope, also termed cutaneous lymphocyte antigen, is known to bind to E-selectin and defines a human T cell subset preferentially found in inflamed skin. Activated T cells can express a functional form of the P-selectin glycoprotein ligand-1 (PSGL-1), the major ligand known for P-selectin. Here we show that PSGL-1 can exist in two forms, of which only one carries the HECA452 epitope and binds to E-selectin, while the other only binds to P-selectin. We have analyzed the glycoprotein ligands for E- and P-selectin on the mouse CD8+ T cell clone 4G3 at 4, 8, and 12 days after antigen-specific activation. Only at day 4 did the cells bind to E-selectin, whereas cells at all three activation stages bound to P-selectin. Expression of the HECA452 epitope correlated with E-selectin binding. In affinity isolation experiments, PSGL-1 was isolated as the major ligand by E-selectin-IgG and by P-selectin-IgG; however, PSGL-1 only bound to E-selectin at day 4, whereas it bound to P-selectin at all three activation stages. Immunoprecipitated PSGL-1 from cells at day 4, but not from cells at days 8 and 12, was recognized in immunoblots by monoclonal antibody HECA452. In immunoblots of total extracts of cells at day 4, HECA452 recognized a 240/140-kDa pair of protein bands as the major antigen. These bands could be completely removed by depletion of cell extracts with anti-PSGL-1 antibodies. Our data suggest that the carbohydrate requirements for binding of PSGL-1 to P-selectin differ from those necessary for binding to E-selectin. Furthermore, we conclude that the major glycoprotein carrier for the HECA452 epitope on activated 4G3 cells is PSGL-1.

Animals↗
PubMed1997

Ruptured vertebrobasilar junction aneurysm associated with basilar artery fenestration.

A case of a ruptured saccular aneurysm arising from the proximal portion of a partially duplicated basilar artery in a 36-year-old woman is reported. CT and lumbar puncture confirmed subarachnoid haemorrhage. Cerebral angiography detected a vertebrobasilar junction aneurysm associated with basilar artery fenestration. The patient underwent successful clipping and coating of the aneurysm by a right lateral suboccipital osteoclastic approach. Embryological development, pathogenesis, diagnostic and therapeutic difficulties of this vascular malformation are discussed in this report.

Adult↗
PubMed1997

Stereotactic radiosurgery of skull base meningiomas.

Between April 1992 and February 1996, 97 patients with skull base meningiomas were treated at our department. The age of these patients ranged from 10 to 80 years. The male/female ratio was 1/2. Fifty-three of these patients had primary open surgery for partial removal or recurrent growth and subsequent radiosurgical treatment. Radiosurgery was performed as a primary treatment in 44 patients. The mean tumor volume was 13.7 cm3 (range: 0.8-82 cm3). These tumor volumes could be covered by mean isodose volumes of 45% (range: 20-70%) and were treated by a mean dose of 13.8 Gy (range: 7-25 Gy) at the tumor border. Six patients underwent radiosurgery with a staged treatment protocol with 4.6-6 months interval. In 78 patients, a total of 102 follow-up scans were available. The remaining 19 patients have not been included in the post-radiosurgical evaluation since the observation time was either too short or the patients were lost for follow-up. The mean interval between gamma knife treatment and last follow-up scan was 18.5 months, with a range from 6 to 46 months. Follow-up imaging (CT, MRI or both) revealed a decreased volume of the tumor in 31 cases (40%). In 44 cases (56%), tumor progression was stopped, and in 3 cases (4%) increased tumor volumes could be observed. In 8 cases marked central tumor necrosis was seen. Neurological follow-up examinations in 76 patients showed a stable neurological status in 71%, ameliorated status in 24% and worsening in 5% of the patients.

Adolescent↗
PubMed1997

Radiosurgical lesioning of the caudate nucleus as a treatment for parkinsonism: a preliminary report.

In ten patients with parkinsonism a radiosurgical operation with the Gamma Knife was performed in which a small lesion was created in the head of the caudate nucleus bilaterally. Preoperatively, in all cases bradykinesia was the main complaint and in all patients conventional drug treatment no longer resulted in a satisfactory response. After a follow-up period of one month six patients showed clear benefit. There was no complication or side effect that could be related to this form of treatment. Pre- and post-operative testing was performed with the Unified Parkinson Rating Scale and with objective motor tasks. The main improvement seen concerned bradykinesia and rigidity: tremor was ameliorated to a lesser extent. Possible mechanisms underlying the improved motor function are discussed as well as the role of lesioning of the striatum in light of transplantation neurosurgery.

Aged↗
PubMed1996

Gamma knife for glioma: selection factors and survival.

PURPOSE: To determine factors associated with survival differences in patients treated with radiosurgery for glioma. METHODS AND MATERIALS: We analyzed 189 patients treated with Gamma Knife radiosurgery for primary or recurrent glioma World Health Organization (WHO) Grades 1-4. RESULTS CONCLUSION: The median minimum tumor dose was 16 Gy (8-30 Gy) and the median tumor volume was 5.9 cc (1.3-52 cc). Brachytherapy selection criteria were satisfied in 65% of patients. Median follow-up of all surviving patients was 65 weeks after radiosurgery. For primary glioblastoma patients, median survival from the date of pathologic diagnosis was 86 weeks if brachytherapy criteria were satisfied and 40 weeks if they were not (p = 0.01), indicating that selection factors strongly influence survival. Multivariate analysis showed that increased survival was associated with five variables: lower pathologic grade, younger age, increased Karnofsky performance status (KPS), smaller tumor volume, and unifocal tumor. Survival was not found to be significantly related to radiosurgical technical parameters (dose, number of isocenters, prescription isodose percent, inhomogeneity) or extent of preradiosurgery surgery. We developed a hazard ratio model that is independent of the technical details of radiosurgery and applied it to reported radiosurgery and brachytherapy series, demonstrating a significant correlation between survival and hazard ratio. CONCLUSIONS: Survival after radiosurgery for glioma is strongly related to five selection variables. Much of the variation in survival reported in previous series can be attributed to differences in distributions of these variables. These variables should be considered in selecting patients for radiosurgery and in the design of future studies.

Adolescent↗
PubMed1996

Craniocerebral birth trauma caused by vacuum extraction: a case of growing skull fracture as a perinatal complication.

A case of growing skull fracture following birth trauma and caused by vacuum extraction is reported in order to emphasize the incidence of this peculiar head injury at the beginning of extrauterine life and to point out its relation to possible neuropsychological disturbances that may appear later in childhood. Delivery by vacuum extraction increases the incidence of perinatal injuries and consequently the incidence of neurological deficits in children. Neurosurgical repair is advocated as the appropriate treatment, with the aim not only of cosmetically correcting the lesion's typical subgaleal protuberance with cranioplasty, but also of performing a water-tight closure of the dura, enabling the cerebral cortex to "fill in" the intracerebral lesion. The surgical technique and gross pathology of the lesion are described together with radiological findings before and after surgery. Reports by other authors are reviewed in an attempt to identify the conditioning factors and pathological features of this traumatic injury to skull and brain in neonates and infants. The literature on cranial fractures associated with intracerebral lesions at this age shows a significant difference in recovery and outcome from that after similar lesions in older children.

Female↗
PubMed1996

Na2B12H11SH (BSH) in combination with systemic hyaluronidase: a promising concept for boron neutron capture therapy for glioblastoma.

OBJECTIVE: In an attempt to optimize the therapeutic potential of Na2B12H11SH (BSH) for boron neutron capture therapy for glioblastoma, the present study investigates the influence of systemically applied hyaluronidase (a glycolytic enzyme that enhances the activity of chemotherapeutic agents in different types of cancer) on the biodistribution of BSH in patients with glioblastoma. METHODS: Patients in two uniform groups (Groups A and B, each of which had 10 patients with histologically confirmed glioblastomas) received BSH at a dose used in earlier therapeutic trials (75 mg/kg of body weight, administered intravenously) 24 hours before surgical debulkment. Patients from Group B received additional hyaluronidase (200,000 IU, administered intravenously) immediately before BSH infusion. Boron concentrations were analyzed by inductively coupled plasma-atomic emission spectroscopy. RESULTS: The application of hyaluronidase was associated with a statistically significant improvement in the tumor (maximum)-to-blood concentration ratio of 1.83 (range, 0.68-3.67) compared with 1.31 (range, 0.8-1.78) with BSH alone. Moreover, with the use of hyaluronidase, there was a tendency for a higher maximal concentration in tumor (not statistically significant). Boron accumulation in glioblastoma tissue was highly selective in both groups, with tumor-to-healthy brain concentration ratios ranging from 6:1 to 20:1. CONCLUSION: These preliminary data suggest that hyaluronidase improves BSH biodistribution and, consequently, the therapeutic potential of this boron carrier. This finding might be of clinical value in the future.

Adult↗
PubMed1996

Acoustic neurinomas with macrocysts treated with Gamma Knife radiosurgery.

Six cases of acoustic neurinomas with macrocystic components are presented. In three cases the cystic portion was within the tumor, while in the other three, the cyst was peritumoral, in the form of a cul-de-sac within the arachnoid, in other words it was not a true tumor cyst. The six tumors are from a series of 74 acoustic neurinomas treated by radiosurgery with a minimum follow-up of 18 months. In all cases, enlargement of the associated cyst was observed as early as 4 months after radiosurgery. Clinical signs and symptoms such as facial weakness, trigeminal symptoms, vertigo and dizziness and coordination disorders developed between 4 and 8 months. In three cases (two intramural cysts and one combined peri- and intramural cyst), subacute microsurgery was performed to treat the progression of neurological symptoms. One case had spontaneous rupture of an intramural cyst, one case of a peritumoral cyst, after progression showed a slow spontaneous size decrease after 2 years, and one case is still under observation. In the reported series, the dose at the tumor margin ranged between 11 and 17 Gy (mean 13.8 +/- 2.5 [SD] Gy) and the maximal dose between 24 and 40 Gy (mean 30.6 +/- 6.2 Gy). In view of the findings in this study, one should perhaps be cautious in advising radiosurgery for this subgroup of acoustic tumors.

Aged↗
PubMed1996

Radiation-induced edema after Gamma Knife treatment for meningiomas.

A retrospective study was performed to analyze some parameters in a consecutive series of 35 Gamma Knife treatments in 34 patients with benign meningiomas. The minimum dose to the tumors was never less than 12 Gy. The follow-up period was from 1 to 3 years. A semiquantitative method of tumor volume assessment was used to measure the tumor response to treatment. The presence and clinical significance of postradiation edema were noted. Even in this short follow-up period, 11 of the 35 tumors were reduced in volume. No tumors increased in size. Edema developed preferentially in nonbasal tumors, especially those around the midline and sagittal sinus. In all but one case where radiation-induced edema was observed was the margin tumor dose 18 Gy or more. It is suggested that doses of 18 Gy or more should probably be avoided in the Gamma Knife treatment of meningiomas and that the greatest care should be taken in selecting non-skull base tumors for this form of treatment.

Adult↗
PubMed1996

Dynamic and static scintigraphic evaluation of cerebral arteriovenous malformations to evaluate radiosurgical treatment.

The radiobiologic changes induced by cobalt-60 gamma irradiation in cerebral arteriovenous malformations (AVMs) is a torpid process. Complete obliteration may take 1 or 2 years or even longer. Neuroradiological modalities like magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) do not provide sufficient information to comprehend this process. Digital subtraction angiography represents an invasive method and is therefore most often performed when complete obliteration is expected. The purpose of this study was to investigate the value of blood pool scintigraphy and functional imaging, such as single photon emission computed tomography (SPECT), to gain more knowledge about the volumetric changes of AVMs treated by radiosurgery. Twenty consecutive candidates for Gamma Knife treatment were selected for comparative MRI/ MRA and scintigraphic studies. All lesions ranging from 0.6 to 18.6 cm3 could be identified on blood pool and SPECT images. Seven patients had repetitive examinations at 3-month intervals to compare the relative volumetric change of the lesion. In 5 cases, a marked decrease in blood pooling was noticed after 3 months, and in 2 patients no significant change was evident. In contrast, MRI/MRA scans done at the same time did not similarly indicate progressive obliteration changes. This preliminary result indicates that scintigraphic evaluation using the blood pool technique is a very sensitive method to describe the relative volumetric change of radiosurgically treated AVMs.

Adolescent↗
PubMed1995

Bovine dowels for anterior cervical fusion: experience in 66 patients with a note on postoperative CT and MRI appearance.

Anterior cervical discectomy and vertebral interbody fusion is a widely used technique in the treatment of radicular or cord compression. Instead of using autologous bone removed from the iliac crest, a heterologous bovine dowel was used for fusion. Sixty-six patients presenting with radicular pain or myelopathy were entered into the study retrospectively. Medial herniated, soft or calcified disc, osteophytes with and without herniated disc material, and bony stenosis at one or two levels were shown by CT or MRI studies. Postoperatively, 88% of the patients noted relief of pain and motor improvement. Most of the patients' sensory deficits and myelopathy improved within 6-12 months. No complications occurred and only one re-operation had to be performed at the same level. In the follow-up period between 1-4 years, no cases of instability after surgery were reported. Operating time and postoperative pain were reduced because bone harvest from the iliac crest was not necessary. In postoperatively performed CT and MRI, the bovine dowel was surrounded by a "halo"-like structure and the specific structure of the bovine implant was still present. No real bony fusion occurred, but clinical stability was equivalent to autologous bone fusion reported in the literature. However, there was no MRI evidence of "living bone tissue" within the bovine dowel. This finding is in contrast to the current belief that the bovine implant is replaced or infiltrated by bony growth.

Adult↗
PubMed1995

Localization of superficial cerebral lesions using a magnetic resonance imaging-guided localizer.

The localization of superficial cerebral lesions may be difficult even if they reach the surface of the cerebral cortex. Intraoperative ultrasound often fails to detect subcortical lesions. A localization device using multiplanar MR-imaging has been designed to project such lesions to the scalp. This device is a hood-shaped grid made of polyethylene tubing filled with paramagnetic contrast agent. In this hemispherical grid the tubes are arranged at a distance of 15 to 30 mm so that the MR-plane always slices perpendicular to the axis of the tubing and depicts a bright spot per tube. It is rapidly filled prior to each MR-examination, placed on the patient's head, and taped to his forehead to avoid unintentional displacement during and after the examination until the projection of the lesion is marked on the skin.

Brain Neoplasms↗
PubMed1995

Stereotactic radiosurgery of skull base meningiomas.

Between April 1992 and March 1994, 48 patients with skull base meningiomas were treated at our department. The age of these patients ranged from 10 to 76 years. The male:female ratio was 1:3. Thirty-seven of these patients had primary open surgery for partial removal and subsequent radiosurgical treatment. In 1 patient a recurrent meningioma after so-called total microsurgical removal was treated radiosurgically. Radiosurgery was performed as a primary treatment in 11 patients. The mean tumor volume was 13.7 cm3 (range: 0.8-82 cm3). These tumor volumes could be covered by mean isodose volumes of 44% (range: 30-70%) and were treated by a mean dose of 15 Gy (range: 8-25 Gy) at the tumor border. One patient underwent radiosurgery with a staged treatment protocol with a 4.6-month interval. In 37 patients, a total of 102 follow-up scans were available. The remaining 11 patients have not been included in the postradiosurgical evaluation, since the observation time was either too short or the patients were lost to follow-up. The mean interval between Gamma Knife treatment and the last follow-up scan was 12 months, with a range from 2.3 to 22.7 months. Follow-up imaging (CT, MRI or both) revealed a decreased volume of the tumor in 9 cases (24%). In 25 cases (68%), tumor progression was stopped, and in 3 cases (8%) increased tumor volumes could be observed (2 patients with malignant meningiomas). In 3 cases marked central tumor necrosis was seen. Neurological follow-up examinations (n = 38 patients) showed a stable neurological status in 74%, ameliorated status in 13% and worsening in 13% of the patients.

Adolescent↗
PubMed1995

Thalamotomy and caudatotomy with the Gamma Knife as a treatment for parkinsonism with a comment on lesion sizes.

Radiosurgery with the Gamma Knife was performed in 12 patients with parkinsonism. In 9 patients small lesions were created in the head of the caudate nucleus bilaterally. Two patients underwent radiosurgical thalamotomy, and 1 patient was treated with caudatotomy and thalamotomy. After a follow-up period of 1-12 months, 9 patients of the caudatotomy group and all patients with thalamotomies showed clear benefit. There was no complication or side effect that could be related to the treatment. Pre- and postoperative testing was performed with the Unified Parkinson Rating Scale and with objective motor tasks. Caudatotomy proved to be an effective treatment for bradykinesia and rigidity, while tremor was ameliorated by thalamotomy. Functional neurosurgery with the Gamma Knife would seem to be a good alternative to open procedures with low morbidity and no mortality. Advantages and drawbacks of radiosurgical techniques for the treatment of parkinsonism are discussed.

Aged↗
PubMed1995

Radiation sensitivity of visual and oculomotor pathways.

Adverse effects of stereotactic radiosurgery on cranial nerves, especially the optic nerve and its pathways, are not yet sufficiently understood. 29 patients who underwent Gamma Knife radiosurgery for benign skull base tumors were reviewed. In all of them, parts of the visual pathways and/or other cranial nerves in the middle cranial fossa received significant doses of radiation. The dose given was correlated with neuro-ophthalmological findings during a follow-up period of 6-24 months. Cranial nerves III, IV and VI within the cavernous sinus, exposed to a dose from 4.5 to 30 Gy, did not develop signs of a neuropathy. Neither did the trigeminal nerve which received between 5 and 20 Gy. In patients with normal neuro-ophthalmological findings prior to radiosurgery, the visual pathways tolerated a dose between 7.5 to 15 Gy. However, in a group of patients with visual deficits before treatment and where the visual fibers received between 6 and 16.6 Gy, 31% deteriorated afterwards. These results indicate that the visual pathways are more at risk for radiation damage than the other cranial nerves in the region and that they may be even more vulnerable to radiation if prior to radiosurgery their function has been compromised by tumor or previous surgery.

Brain Neoplasms↗