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Biomedical subjects

H J Synowitz

Publications and source records attributed to H J Synowitz.

At least 19 recordsLinked to original sources
PubMed2003

Pitfalls in surgery of meningeomas of the free tentorial edge.

Clinical experiences from 15 meningeomas located on the free edge of the tentorium are reported. Unexpected findings and complications found in five patients are presented in detail: Despite successful removal without postoperative morbidity after a presigmoid approach the preoperative loss of function of the ophthalmic nerve may cause increasing keratitis, which may result in blindness over the years after surgery. Before a presigmoid approach is performed, angiography or magnetic resonance angiography is advised, because the patient may have only one sigmoid sinus on the tumor side. An acute subdural hematoma as a complication of surgery may not only occur after, but also during surgery with the patient in the semi-sitting position. When a space occupying tumor of the tentorium is discovered, there may be an additional spinal one. If total removal of an extensive tumor of the free edge of the tentorium appears too hazardous, a two-stage strategy with a one year interval may lead to success.

Aged↗
PubMed2000

Practicability of intraoperative microvascular Doppler sonography in aneurysm surgery.

Inadvertent narrowing of parent or branching vessels is one major cause of unfavorable outcome from aneurysm surgery. Intraoperative micro-Doppler sonography of arterial brain vessels during surgery for cerebral aneurysms of the anterior circulation was performed in 50 patients and compared retrospectively with 50 patients, who were operated upon without micro-Doppler sonography. Intraoperative micro-Doppler sonography demonstrated the need for repositioning of the clip in 12 instances. Outcome after surgery with micro-Doppler sonography appeared slightly better than without. Micro-Doppler sonography is concluded to be a practicable adjunct to routine aneurysm surgery.

Adult↗
PubMed1999

Selective proteolytic cleavage of IL-2 receptor and IL-6 receptor ligand binding chains by neutrophil-derived serine proteases at foci of inflammation.

Traumatic brain injuries induce a strong, locally restricted inflammatory response. Here we demonstrate that activated neutrophils infiltrate the site of tissue destruction and release large amounts of enzymatically active elastase, cathepsin G, and proteinase 3. High intracerebral protease concentrations were found to be accompanied by a reduced inhibitory potential at foci of inflammation. In 39 neurotrauma patients, a temporal correlation between the protease release from neutrophils and the solubilization of interleukin-2 (IL-2) receptor and IL-6 receptor ectodomains at sites of tissue destruction was observed, suggesting that neutrophil-derived proteases may play a crucial role in the cytokine receptor shedding at foci of inflammation. Under in vitro conditions, the cleavage of membrane-bound IL-2Ralpha was found to be predominantly catalyzed by elastase and, to a lesser extent, by proteinase 3. Cathepsin G was found to be incapable of solubilizing this receptor. In contrast, the cleavage of the IL-6R 80 kDa chain was catalyzed by cathepsin G but not by elastase or proteinase 3. The receptor fragments released by the action of these enzymes were found to retain their ligand-binding capacity. These results strongly suggest a pathophysiologic role of neutrophil-derived serine proteases, particularly in regulation of the expression of functional IL-2 and IL-6 receptors at foci of inflammation.

Adolescent↗
PubMed1997

Immunohistochemical detection of vascular growth factors in angiomatous and atypical meningiomas, as well as hemangiopericytomas.

The arachnoideal compartment provides the vascular sources for three different tumor types rich in vessels: angiomatous meningioma, some atypical meningioma with high vascularity and meningeal hemangiopericytoma. We investigated immunohistochemically the expression and distribution of vascular mitogenes in 7 angiomatous meningiomas, 8 atypical meningiomas with high vasculature and 4 hemangiopericytomas. On the one hand it should be studied which vascular growth factors such as VPF/VEGF-1, VPF/VEGF-2, bFGF, PDGF and TGF-alpha could be responsible for the close meshwork of vessels within the tumors. On the other hand we were interested in whether or not there are differences in vascular mitogens between slowly growing angiomatous meningiomas and both other types with their increased tendency to recur. PDGF and TGF-alpha were extensively expressed in the endothelium and smooth muscle cells of the vessels, as well as tumor cells. VEGF-2 could only be found in endothelial cells of all three tumor entities. bFGF was localized in some vessels of angiomatous meningiomas and VEGF-1 revealed a very low expression with a localization comparable with VEGF-2. Moreover, uPAR was diffusely expressed in nearly all tumor cells and endothelial cells. The fact that tumor cells of hemangiopericytomas and meningiomas did not show any immunohistochemical reaction with VEGF's could indicate a lower priority of these growth factors for neovascularization in this type of neoplasm. A different expression of vascular mitogens between benign angiomatous meningiomas and atypical meningiomas as well as hemangiopericytomas with their tendency for recurrence could not be observed. The morphological evidence for extravasates of IgG-proteins, Fibrin and Fibronectin due to VPF-effects seems not to be a renouncable condition for neoangiogenesis in the tumors investigated.

Adult↗
PubMed1996

Immunohistochemically detectable p53 and mdm-2 oncoprotein expression in astrocytic gliomas and their correlation to cell proliferation.

The aim of this report was to investigate the expression of the p53 and mdm-2 oncoproteins in astrocytic gliomas and to assess their interrelation to proliferating activities. Using monoclonal antibodies directed against p53 and mdm-2, these proteins were stained immunohistochemically in 60 astrocytic brain tumors with different histologic grade. Positive p53 stained nuclei were detected in 25.4% of the tumor cases. Mdm-2 staining products were only localized in 10.5% of specimens. Significant correlations could be found between p53, MIB-1, PCNA and mitotic index on the one hand, and tumor grade on the other hand. There were no clear relations between mdm-2 expression and proliferation markers. The grade of ploidy has a lower priority for the proliferating activity. In most cases mdm-2 immunoreactivity was strongly associated with a low or negative p53 expression.

Astrocytoma↗
PubMed1993

[Primary leptomeningeal sarcomatosis in a 26-year-old patient].

Primary malignant mesenchymal tumours were seen in 2.4 per cent of all autopsy cases with primary CNS-tumours. Primary leptomeningeal sarcomatosis is rare in this group of tumours. We discuss the rare disease on the basis of the case history of a 26-year-old patient.

Adult↗
PubMed1989

[A completely thrombosed giant aneurysm in an infant].

In a 16-month-old boy completely thrombosed aneurysm in the midline region (Regio pinealis) was successfully extirpated. The clinical symptoms were reduced by a pressure hydrocephalus, which was caused by an occlusion of the passage of the cerebrospinal fluid at the level of the aquaeductus. In the histological picture the inner third of the wall of the aneurysm was imposing as a necrosis with a membrane-like layer of elastin-like proteins on the outward side and adjacent loose connective tissue.

Arteries↗
PubMed1989

[Cerebral artery aneurysm of the para-ophthalmic artery segment of the internal carotid artery (C4 section)].

The number of surgically treated patients with aneurysms included 14 aneurysms located in the Paraophthalmica segment of the A. carotis interna. In six patients only indirect methods (wrapping, establishment of an extra-cranial-intracranial microanastomosis) were used. Clipping of the aneurysmal neck with resection of the aneurysm was reached in six patients. In each case the Processus clinoideus anterior was milled off and the aneurysmal neck was prepared in a sufficient manner for the establishment of the clipping. Intraoperative problems with rupture of the aneurysm and the requirement of definite clipping of the A. carotis interna occurred in two patients. Both patients survived the intervention. One death occurred, it was a young man with a primarily inconspicuous postoperative course and the death was caused by a thrombosis in the carrier vessel.

Adult↗
PubMed1989

[Manifestation of sarcoidosis of the optic nerve].

Under the suspicion of an optic nerve glioma a resection of the optic nerve tumour was carried out in a 58-year-old female patient with an amaurosis on the right side. The diagnosis of the sarcoidosis of the Nervus opticus was only established on the basis of the histological findings obtained in the resected optic nerve. Even after a period of observation of five years no further general pathologic signs of the sarcoidosis appeared, so that it could be assumed that this was the case of an isolated sarcoid affection of the optic nerve.

Cranial Nerve Neoplasms↗
PubMed1988

[Meningitis as a complication of anterior-sacral meningocele].

A 19-year-old young man was admitted with a serious clinical picture of an infected anterior sacral meningocele. Escherichia coli was identified as the pathogenic organism in the spinal putrid fluid. A catheter percutaneously introduced in the hernial sac served as an external drainage of the fluid. At the same time a systemic antibiotic treatment was carried out. After the sanation, the opening of the meningocele was surgically closed in the interval transdurally from the dorsal direction. For this fibrinous adhesive was used in addition to the suture. After six months the hernial sac closure could be demonstrated in the check-up myelo- and computer tomogram.

Adult↗
PubMed1987

[Recurrent meningioma. Analysis of 43 surgical interventions in meningioma of the sphenoid bone].

A total of 43 operations were carried out in 37 patients with a meningioma of the wing of the sphenoid bone or a Tuberculum sellae meningioma. In 18 cases the primary extirpation could be performed and in 18 patients the intervention only consisted of a resection. The removal of any meningioma tissue was classified as an extirpation. If a residual part of whatever size of the tumour was left, the intervention was declared to be a resection. Six patients died, 31 were submitted to a control examination. All 14 patients in whom an extirpation was carried out showed no signs of a renewed tumour growth within the observation period of 2 to 10 years after obtaining the computer-tomographical findings. In six of the 16 patients in whom only a resection was possible a second operation was carried out. An extirpation could be performed in four of these patients. Among the remaining ten patients (period of observation 2 to 6 years) five showed a further increase of the tumour size, in four patients no tendency of a growth could be proved, and one patient had died. In the postoperative assessment we distinguish between a residual tumour and a new tumour growth. A renewed tumour growth is present if the computer tomogram shows signs of meningioma tissue although earlier postoperative checks had not shown this. In the postoperative control examinations the residual tumours should be differentiated with respect to their importance as (a) a residual tumor with a growth tendency and (b) a residual tumour without a growth tendency.

Adolescent↗
PubMed1987

[The transcallosal approach--surgical technics].

The transcallosal access as a surgical route to the supratentorial ventricular system is discussed. The experience gained in 31 microneurosurgical interventions with this access is dealt with. This route in particular permits an assessment of the local operability. Among the 25 histologically confirmed tumours of this region 19 belonged to the neuroepithelial tumours. Because of the peculiarities of this tumour type the final results are unsatisfactory in spite of the microsurgical procedure and the utilisation of an optimum access.

Adolescent↗
PubMed1987

[Surgery of aneurysms of the cerebral arteries--results and problems].

Surgery has been performed on 100 intracranial aneurysms during the past seven years. Of these, 96 involved the application of microsurgical techniques and could definitely be clipped. Lethality was 8%. Post-surgical deterioration of the clinical neurological status was observed in another 20 patients, but vanished subsequently in 16 of them. Immediate surgery within 48 hours of the subarachnoidal hemorrhage is recommended to avoid subsequent hemorrhage and prevent severe vasospasmic phenomena. Only patients whose general status is good (Hunt and Hess degree 1 or 2) are suitable for immediate surgery.

Adolescent↗
PubMed1987

[Supratentorially located angioblastoma in childhood. Case report].

In an 11-year-old girl an angioblastoma in a left parietal position has been successfully removed by a surgical intervention. The process consisted of a highly vascularized tumour part of a firm consistency, which was located in a large cyst. The pre-operatively established computer tomogram showed a hypodensity in the sense of a left parietal cyst and a pronounced environmental oedema. The occurrence of this tumour form in childhood and in the supratentorial section is a rarity.

Brain Neoplasms↗
PubMed1987

[Aneurysm surgery in relation to secondary intracranial findings].

In 116 patients operated on because of aneurysms we found 125 aneurysms, one convexity meningioma, and one A. V. supratentorial angioma. In 9 patients (8%) more than one aneurysm were found. In 8 patients there were double aneurysms and on one case 4 aneurysms, 18 of these 20 aneurysms were clipped. If these were situated on the same side they were treated simultaneously. If they were situated on two sides, the aneurysms were clipped in two surgical interventions. In 2 patients one of the two aneurysms remained untreated. Two interventions were also carried out for the combination aneurysm/tumor. After clipping the aneurysm, the meningioma was removed after an appropriate interval.

Brain Neoplasms↗
PubMed1986

[A simple aid for the localization of intracranial tumors in cerebral computer tomography].

The exact localizing co-ordination of small intracranial, space-occupying processes is sometimes difficult. As a simple aid for exact localization of such processes a "rod headband" is presented, which consists of a leather strap with exchangeable plastic rods and can be put on the patient's forehead for a CT examination. The artifact-free representation of the little rods in the axial CT layers makes it possible to localize intracranial processes more exactly. Until now, the "rod headband" has been used for ten patients with the following indications: Needle biopsies of intracranial space-occupying processes, cerebral abscess punctures, haematoma punctures, and as a pre-operative localization aid for intracranial tumours.

Brain Abscess↗