Search PubMed⌕ Search

Biomedical subjects

R Schober

Publications and source records attributed to R Schober.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1987

Prolonged extracorporeal CO2-removal in severe adult respiratory distress syndrome. Neuropathological observations in two cases.

Extracorporeal CO2-removal (EC-CO2-R) using a membrane lung system was applied for 12 and 20 days respectively in two young men with adult respiratory distress syndrome (ARDS). Neuropathological examination revealed only moderate hypoxic changes of unusual distribution. In the first case nerve cell loss in Sommer's sector of the hippocampus and focal incomplete necroses in both putamina were interpreted as the result of cardiac arrest at the onset of the disease rather than of chronic hypoxia. Findings in the second case were confined to nerve cell necroses of a minor degree in the cerebral cortex. Remarkably, the cerebellum was spared in both cases. Our observations suggest that EC-CO2-R was not associated with neuropathological findings which could be attributed specifically to this procedure.

Adolescent↗
PubMed1986

Laser-induced alteration of collagen substructure allows microsurgical tissue welding.

Tissue welding is a potentially important biomedical application of laser technology. The structural alterations basic to this phenomenon were studied in experimental repair of lesions of the rat carotid artery and sciatic nerve. A modified neodymiumdoped yttrium-aluminum-garnet laser operating at a wavelength of 1.319 micrometers was used in conjunction with conventional suture techniques. Histological and fine-structural analysis revealed a homogenizing change in collagen with interdigitation of altered individual fibrils that appeared to be the structural basis of the welding effect.

Animals↗
PubMed1986

Osteoclastomas of the petrous bone.

Two cases of osteoclastoma of the petrous bone are presented that were clinically taken for tumors of the glomus jugulare. The petrous bone is a very uncommon location for such tumors, and only six cases have been reported in the English literature. The histopathological features as well as the clinical course are described, and the literature is critically reviewed.

Female↗
PubMed1986

Cohort analysis of Ontario suicide rates, 1877-1976.

Birth cohort studies of suicide rates in Alberta, the United States and Australia indicate that within each generation, suicide rates increase with age. Such studies argue that cohort-specific suicidal risk, together with present high suicide rates among young people predict even higher rates as these generations grow older. Ontario data from a 100-year period demonstrate that within birth cohorts suicide rates consistently increase with age, peak between ages 50 and 70, then decline. Gradual increases in mean suicide rates result in every birth cohort having higher suicide rates than the preceding cohort at almost every age level. These trends combine to produce a regular birth cohort effect and a steady shift in cross-sectional data to higher rates of suicide among younger age groups. Abrupt increases in suicide rates occurring during the Great Depression had only transient effects on birth cohort and cross-sectional curves. Results provide weak support for the hypothesis of cohort-specific suicidal risk and clarify the factors which produce birth cohort effects.

Adolescent↗
PubMed1983

[Fine structure of intrafusal and extrafusal nerve segments of the rat muscle spindle after sciatic nerve transsection].

Intrafusal and extrafusal nerve segments in muscle spindles from lumbricalis muscles of the hindpaw of the rat were studied by electron microscopy from 10 h to 5 days after severance of the sciatic nerve. In several spindles examined, nerve fascicles piercing the spindle capsule in the equatorial region contained a large myelinated, a smaller myelinated, and an unmyelinated fiber. Unmyelinated fibers were not present in small fascicles leading to the polar region. The changes in the extrafusal nerve segments followed the pattern of Wallerian degeneration. Intra-axonal glycogen deposits were prominent in sensory fibers. The unmyelinated fibers were the earliest to degenerate, the large myelinated ones the latest. Differences between motor and sensory fiber degeneration emerged in their preterminal intrafusal segments and were analogous to those of the nerve endings. Terminal nerve fibers in the spindle equator succumbed to attack of mesenchymal cells, leaving extensive basement membrane reduplications around myelin debris-laden Schwann cells, while polar fibers were engulfed by Schwann cell processes, leaving regular bands of Büngner.

Animals↗
PubMed1983

An unusual cytoplasmic organelle of the perineurium in a case of Duchenne muscular dystrophy.

An unusual cytoplasmic organelle was found in the perineurial sheath of intramuscular nerves in a case of Duchenne muscular dystrophy. It was composed of alternating layers of ribosomes and fibrillar material helically wound around a core of cytoplasm. Comparable organelles have been described in leukemic and other neoplastic cells as well as in the developing cutaneous sensory corpuscle of Grandry.

Biopsy↗
PubMed1982

[On the fine structure of muscle spindle terminal in the lumbricalis muscles of the rat after section of the nerve (author's transl)].

The nerve endings in muscle spindles from lumbricalis muscles of the hindpaw of the rat were studied by electron microscopy from 10 h to 7 days after section of the sciatic nerve. No sensory endings were found after 5 days and no motor endings after 3 days. Early changes in sensory endings included accumulation of lamellar bodies, mitochondrial swelling or shrinkage, an edematous appearance of the cytoplasm and disruption of membranes. The predominant way of removal was phagocytosis by activated mesenchymal cells; other endings were incorporated into the sarcoplasm as electron dense bodies. Early changes in motor endings included aggregation or swelling of synaptic vesicles, swelling or shrinkage of mitochondria, edematous change of the cytoplasm and disruption of membranes. The predominant way of removal was incorporation into the cytoplasm of adjacent Schwann cells and degradation to phagolysosomes. Sites of removed sensory endings could be identified by basement membrane reduplication, while the intact subsynaptic apparatus of removed motor endings was either loosely covered by Schwann cell processes, or by fibrillar material, or appeared empty.

Animals↗
PubMed1979

[Cranial mucormycosis with thrombosis of the sinus cavernosus (author's transl)].

A case of mucormycosis in a 45 year-old woman with uncontrolled diabetes is reported. Following dental extractions, the patient presented with total ophthalmoplegia, chemosis and complete sensory loss of the right fifth cranial nerve. Exophthalmus was not present. Although a fungal infection was suspected, administration of Amphotericin B was avoided because of renal insufficiency. After temporary clinical improvement with high doses of antibiotics, signs of right seventh and eighth cranial nerve paralysis and of thrombosis of the right ophthalmic artery developed. The patient expired after six days. Autopsy disclosed extensive mucormycosis with involvement of the nasal cavity and paranasal sinuses, soft tissues and bones of face and orbit, cranial nerves, meninges and base of the brain, as well as mycotic thrombosis of the right cavernous sinus and the internal carotid, ophthalmic and maxillary arteries. The spread of infection is detailed, and the importance of an early diagnosis is stressed.

Carotid Artery Diseases↗