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Biomedical subjects

R Schober

Publications and source records attributed to R Schober.

At least 19 recordsLinked to original sources
PubMed1995

Multiple paraneoplastic syndromes in a patient with antibodies to neuronal nucleoproteins (anti-Hu).

We report the clinical and autopsy studies of a patient with an unusual combination of multiple paraneoplastic neurological syndromes in association with antibodies to a 35-40 kDa neuronal nucleo-protein (anti-Hu). Neurological disease preceded the detection of a small cell carcinoma of the lung. The patient had combined sensory and motor neuronopathy or neuropathy, cerebellar degeneration, brain-stem and limbic encephalitis, and clinical evidence of the Lambert-Eaton myasthenic syndrome and gastrointestinal pseudo-obstruction of paraneoplastic origin.

Autoantibodies↗
PubMed1993

Fine structure of zonal changes in experimental Nd:YAG laser-induced interstitial hyperthermia.

Interstitial thermotherapy using Nd:YAG-laser induced hyperthermia is a new stereotactic method for the treatment of brain tumors in poorly accessible regions. To provide a basis for the underlying tissue alterations, we have analyzed the spatial and temporal pattern of interstitial laser hyperthermia lesions in the normal rat brain by histological, immunohistochemical, and electron microscopical methods. The acute changes corresponded to the temperature gradient surrounding the laser probe and showed a distinct zonal architecture. Membrane destruction on a cellular and subcellular level appears to be of major significance in the pathogenesis of the laser lesion. The tissue reaction followed the course known for coagulation necrosis and resulted in a well-defined defect. These results, although limited by the choice of the experimental model, may be helpful in the interpretation of images obtained in future applications of interstitial thermotherapy.

Aluminum Silicates↗
PubMed1993

Symmetrical neurofibroma with Schwann cell predominance and focal formation of microneurinomas.

A case of symmetrical neurofibroma with onion bulbs in various stages of development and progression to microneurinomas is presented. Immunohistochemistry with differentiation and growth factor markers as well as electron microscopy showed a Schwann cell origin of the concentrically arranged cells. The onion bulbs differed from those of hypertrophic neuropathy by their more compact structure. A partial expression of cellular proliferation markers in the onion bulbs was consistent with a multifocal proliferative activity, confirming the neoplastic nature of the lesion.

Adult↗
PubMed1992

Gliofibroma: immunohistochemical analysis.

A case of gliofibroma occurring in an adult patient as a large circumscribed supratentorial tumor is reported. The bimorphic pattern was substantiated and further analyzed by immunohistochemistry. Some evidence in favor of collagen production by mesenchymal and/or inflammatory cells leading to a progressive fibrous replacement of the glial cells in this particular tumor type is presented.

Adolescent↗
PubMed1992

Occlusive microangiopathy by immunoglobulin (IgM-kappa) precipitation: pathogenetic relevance in paraneoplastic cryoglobulinemic neuropathy.

Histological, immunohistochemical and ultrastructural sural nerve and skin biopsy findings in a case of cryoglobulinemia secondary to an IgM-kappa-producing non-Hodgkin lymphoma are described. The main finding was an occlusive microangiopathy present in both the sural nerve and the skin. Widespread cryoglobulin deposits of the proliferated vasa nervorum were associated with pronounced changes probably evoked by ischemia. Moderate perivascular inflammation, but no florid vasculitis was additionally present. Our observations indicate that occlusive microangiopathy by precipitated cryoglobulins may be a relevant pathogenetic factor in cryoglobulinemic peripheral neuropathy.

B-Lymphocytes↗
PubMed1992

Vascular permeability changes in tumours of the peripheral nervous system.

Vascular permeability changes were examined in 34 tumours of the peripheral nervous system by immunohistochemical demonstration of serum proteins as endogenous tracers. The blood-tumour barrier was impaired in the reticular (Antoni type B) portions of neurinomas (Schwannomas) and in cutaneous neurofibromas but was similar to the normal blood-nerve barrier in fibrillary (Antoni type A) neurinomas, in most neurofibromas, in ganglioneuromas and in anaplastic tumours. These differences in permeability are discussed in relation to aspects of pathological tumour vascularization, the histogenesis of microcystic changes, and systemic therapeutic approaches.

Adult↗
PubMed1992

Immunotherapy with stimulated autologous lymphocytes in a case of a juvenile anaplastic glioma.

The effect of immunotherapy with stimulated autologous lymphocytes (SAL) in malignant gliomas is documented and discussed in a bioptical and autoptical case study. A five-year-old child with a recurrently operated and radiated right hemispheric anaplastic astrocytoma died six weeks after immunotherapy with mitogen-activated killer cells and recombinant Interleukin-2. The autopsy revealed a large butterfly glioma with partially necrotic gelatinous tissue at the site of the SAL reservoir. The tumor cell density on the right was less than on the left hemisphere, and T-lymphocyte content was higher on the right hemisphere. These results demonstrate a local effect of SAL therapy in vivo, although the tumor progression as a whole could not be stopped. They also demonstrate the need of a detailed neuropathological examination in all cases of immunotherapy of malignant gliomas.

Brain Neoplasms↗
PubMed1991

Stereotactic laser therapy in cerebral gliomas.

The 1.06 micron Nd:YAG laser and a new fiberoptic delivery system, the Interstitial Thermo-Therapy (ITT) laser fibre, allows stereotactic interstitial irradiation of cerebral tumours. In experimental rat brain studies we found typical laser-tissue effects with a central necrosis and a sharply demarcated oedema towards the normal brain. The size of the lesion depended on the energy and exposure time applied. In a pilot series we treated 5 patients with cerebral gliomas WHO grade II-III in functionally important regions and monitored the therapeutic effects by MR imaging and PET scan. Early post-operative results showed irreversible necrotic changes in the tumour centre and reversible oedematous changes at the tumour margin. Long-term results will show if stereotactic interstitial laser therapy is a useful supplementary method in the treatment of malignant cerebral tumours.

Animals↗
PubMed1991

Gliomatosis cerebri: bioptical approach and neuropathological verification.

Gliomatosis cerebri is rarely encountered and its intra vitam diagnosis has remained difficult. We present biopsy and autopsy findings in three cases that are representative of diffuse glioma, gliomatosis cerebri and diffuse glioblastosis, a modification of the subclassification proposed by Zülch31. Stereotactic biopsy in conjunction with nuclear magnetic resonance tomography (MRT) is recommended as the diagnostic procedure in suspected cases. Immunohistochemical examination with a panel of neuroectodermal markers is helpful in the differential diagnosis but has to take into account that reactive astrocytes may be closely intermingled with the neoplastic glial cells.

Adult↗
PubMed1991

Encephalo-myelo-radiculo-ganglionitis presenting as pandysautonomia.

A 68-year-old man developed pandysautonomia with severe orthostatic dysfunction, fixed heart rate, low serum levels of norepinephrine and epinephrine, absent sympathetic skin responses, and pupillary abnormalities. CSF protein was 92 mg/dl. In spite of a good recovery following corticosteroid administration, a relapse occurred, with accompanying sensory symptoms confined to both arms. Fatal sudden cardiac arrest occurred after 4 months. Autopsy revealed numerous lymphocytic infiltrates, predominantly in autonomic and sensory ganglia and, to a lesser extent, in the nerve roots, spinal cord, and brainstem without evidence for an underlying tumor. This case provides histopathologic evidence for an inflammatory etiology of panautonomic neuropathy in some patients.

Aged↗
PubMed1989

Primary intracerebral malignant lymphoma presenting with ophthalmological symptoms: bioptical and autoptical case study.

A case of primary malignant lymphoma of the brain with preceding first unilateral, then bilateral uveitis and retinochorioiditis is presented. The diagnosis was established on brain biopsy material using immuno-histochemical methods. The autopsy disclosed a polymorphous immunocytoma with bilateral brain involvement including structures of the posterior optic pathways. Clinical and pathogenetic implications regarding this "oculo-cerebral type" of malignant lymphoma, which has been only seldom reported in the literature are discussed.

Brain Neoplasms↗
PubMed1989

Variation in retinal changes and muscle pathology in mitochondriopathies.

A variety of retinal changes that have so far not been classified under mitochondriopathies can now be included in this group, since muscle biopsy has identified ragged-red fibers with pathological mitochondriae. The ophthalmological findings in our relatively large group of 12 patients with mitochondrial myopathies are compared with the spectrum of myopathic findings. No obvious correlation exists between the severity of the pathological retinal changes and the characteristic of the myopathic alterations. In addition to fine pigmentation and depigmentation, severe dystrophic changes of the retina, pigment epithelium, and the choroid were observed. In two patients with severe chorioretinal dystrophy the correlation with generalized mitochondriopathy was not suspected prior to muscle biopsy.

Adolescent↗
PubMed1989

[A rapidly expanding epithelial skull cyst of uncertain origin].

A rapidly expanding huge cystic lesion of the skull was the cause of unilateral exophthalmus in a 33 year old man. The differential diagnosis included an aneurysmal bone cyst, keratinous cyst, leptomeningeal cyst and intraosseous hemangioma. Although an epithelial lining was verified, the exact nature of the cyst could not be clarified despite immunohistochemical and electron microscopical investigations.

Adult↗
PubMed1988

Long-term investigations of laser-assisted microvascular anastomoses with the 1.318-micron Nd:YAG laser.

Laser-assisted microvascular anastomoses can be performed with the most diverse types of laser (Dujovny et al: 4th Annu Gen Sci Meet LANSI, 1986; Godlewski et al: World J Surg 10:329-333, 1986; Gomes et al: Rev Hosp Clin Fac Med Sao Paulo 37:255, 1982; Quigley et al: Laser Surg Med 5:357-367, 1985; Quigley et al: Lancet 1:334, 1985; Quigley et al: Neurosurgery 18(3):292-299, 1986; Jain: J Microsurg 1:436-439, 1980; Jain: Lancet 2:816-817, 1984; Krueger and Almquist: Lasers Surg Med 5:55, 1985; Neblett et al: Neurosurgery 19(6):914-934, 1986; Schober et al: Science 232:1421-1422, 1986; Ulrich et al: 2nd Annu Gen Sci Meet LANSI, 1984; Ulrich and Bock: Optoelectronics in Medicine, Spring-Verlag 418-423, 1986). However, postoperative complications in the form of thromboses and aneurysmatic sacs could be detected in 7-29.8% in longitudinal investigations. By conversion of the beam geometry (1.3 micron Nd:YAG laser, 200 micron light conductor) and use of three concentrically applied 10.0 backstitch sutures in 25 end-to-end anastomoses of the common carotid artery of adult albino rats 0.8-1.2 mm in diameter, early and late complications could be markedly reduced (12%).

Anastomosis, Surgical↗
PubMed1988

Congenital anaplastic astrocytoma with favorable prognosis. Case report.

A large intracranial tumor that caused macrocrania leading to dystocia was demonstrated by prenatal ultrasound examination. After birth, computerized tomography (CT) confirmed the presence of a giant supratentorial tumor with a large cyst. When the infant was 20 days old, the tumor was radically extirpated. Neuropathological examination revealed an astrocytoma with focal signs of anaplasia showing a macrocyst as well as multiple microcysts resulting from hemorrhages into the tumor. Although no adjuvant radio- or chemotherapy was administered, the child had nearly normal psychomotor development without clinical or CT evidence of tumor recurrence, and is now 3 years old.

Astrocytoma↗