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R J Seitz

Publications and source records attributed to R J Seitz.

124 records · Page 7Linked to original sources
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↗
PubMed1987

Immunohistochemical demonstration of serum proteins in human cerebral gliomas.

The leakage of different serum proteins, including immunoglobulins, into human cerebral gliomas was studied by use of the unlabeled peroxidase-antiperoxidase (PAP) method on cryostat and paraffin sections. Our series of 50 tumour biopsies included 21 isomorphic astrocytomas and oligodendrogliomas (grade II), 19 anaplastic astrocytomas and oligodendrogliomas (grade III), and 10 glioblastomas (grade IV). The immunohistochemical staining of the serum proteins was similar on paraffin and cryostat sections and graded with respect to occurrence, distribution, and intensity. Serum proteins of a small hydrodynamic radius with a low serum concentration (prealbumin) or with a high serum concentration (albumin) were diffusely present in the interstitial spaces of all glioma types. Serum proteins with a medium molecular size and variable serum concentrations, i.e. IgG, IgA, and ceruloplasmin, were detected preferentially in anaplastic gliomas and in glioblastomas (grade III and IV) displaying comparable distribution patterns but different intensities. Alpha-2-macroglobulin a serum protein with a large hydrodynamic radius was also demonstrated in grade III and IV gliomas, whereas IgM and beta-lipoprotein being the largest serum proteins tested were almost restricted to blood vessels and tumour necroses. In addition, most serum proteins occurred with high intensities in those areas of isomorphic grade II gliomas that showed a macro- or microcystic or mucinous tissue degeneration. The varying immunohistochemical staining results for the serum proteins studied indicate that the blood-brain barrier within isomorphic and anaplastic gliomas is not completely disturbed. It appears that the vascular permeability is preferentially increased for small-sized serum proteins, whereas the leakage of larger serum proteins into the glioma interstitium seems to depend on the tumour type and on increasing malignancy.

Blood Proteins↗
PubMed1987

The leakage of serum proteins across the blood-nerve barrier in hereditary and inflammatory neuropathies. An immunohistochemical and morphometric study.

The leakage of eight different serum proteins and immunoglobulins across the blood-nerve barrier (BNB) was studied by means of the peroxidase-antiperoxidase method in hereditary and inflammatory neuropathies and graded semiquantitatively with respect to endoneurial staining intensity and distribution. These data were compared with the degree of alterations of the myelinated nerve fibre population evaluated by morphometric analysis. Our series of 18 human sural nerve biopsies included seven hereditary neuropathies (three HMSN I, two HMSN II, two tomaculous neuropathies), nine inflammatory neuropathies (seven polyneuritis, two hypertrophic neuritis) and two normal controls. In HMSN II and in tomaculous neuropathy there was no enhanced endoneurial staining for serum proteins despite of a severe nerve fibre loss, whereas in HMSN I a rise of serum proteins of small and moderate molecular size like albumin and IgG was demonstrated in the endoneurial space indicating an impaired BNB function. Qualitative changes of the BNB with leakage also of high molecular weight proteins were observed in polyneuritis and hypertrophic neuritis, irrespective of the degree of nerve fibre changes. Our results show that fibre loss and alteration of the BNB are not correlated. The unselective leakage of serum proteins through the BNB appears to be a characteristic change in inflammatory neuropathies leading to proteinous edema. With regard to the subperineurial accentuation of the endoneurial edema it will be discussed that the vascular diffusion barrier is more fragile than the perineurial diffusion barrier.

Adolescent↗
PubMed1987

Ultralong-lasting nerve block: triethyldodecyl ammonium bromide is probably a neurotoxin rather than a local anesthetic.

The profile and duration of action of triethyldodecyl ammonium bromide (TEA-C12) on natural spike activity of rabbit aortic nerve was examined. To study the profile of action, a segment of the aortic nerve of anesthetized rabbits was placed in a perfusion chamber and exposed to increasing concentrations of TEA-C12 and, for comparison, of procaine. Total nerve activity was recorded continuously and its change related to drug concentrations (concentration/effect curves). The half-lives of onset time after drug administration and recovery following drug-washout were also determined. To study the duration of conduction block induced by TEA-C12, the aortic nerve of anesthetized rabbits was exposed to a concentration slightly higher than the minimal blocking concentration for an average time of 130 min after complete conduction block occurred. Three to 40 days later, the nerves were examined both neurophysiologically and neuropathologically. TEA-C12 blocked nerve activity in a concentration-related manner, as did procaine; however, the onset time (t1/2) was much slower for TEA-C12 (9.2 min) than for procaine (2.2 min). Most importantly, TEA-C12 block could not be reversed within 9 h of drug-washout, whereas all the procaine-blocked nerves completely recovered (t1/2 = 3.0 min). Nerve activity was completely blocked by TEA-C12 and nerve block was accompanied by severe morphological damage with complete loss of myelinated nerve fibers and severe axonal edema of the remaining axons for about 4 weeks. Nerve function completely recovered, but with only partial morphological restoration between day 30 and 40 after the initial block.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1986

Hypomyelination neuropathy in a female newborn presenting as arthrogryposis multiplex congenita.

A female newborn delivered at 32 weeks of gestation presented with multiple joint contractures consistent with arthrogryposis multiplex congenita (AMC). The girl died after a four days course of severe respiratory distress. Autopsy revealed slightly hypoplastic and immature lungs with acute necrotizing bronchopneumonia, and marked consecutive hypoxic brain lesions with severe periventricular haemorrhages. The peripheral nerves including the cranial and spinal nerve roots showed a hypomyelination radiculoneuropathy with well preserved axons and a normal content of Schwann cells. In the skeletal muscles of the arms and legs some fascicles of the extensors were replaced by lipomatous tissue. Since myelination of the white matter in the central nervous system was adequate to the age, this case represents an exclusive maturation disorder of the peripheral myelin sheaths that may be considered causal for AMC.

Arthrogryposis↗
PubMed1986

Application of the avidin-biotin system for post-embedding cytochemical demonstration of a biotin-labeled IgG tracer.

The capacity of the avidin-biotin system for post-embedding cytochemical detection of a biotin-labeled proteinaceous tracer was investigated. By testing modifications of the fixatives, the epoxy embedding medium, and various etching solutions, a procedure was developed to localize specifically the biotinylated tracer on 1-micron thick and thin sections. By use of this technique, a systemically administered IgG tracer was demonstrated after 24 hr throughout the endomysium of mouse skeletal muscle. In the adjoining sciatic nerve, the tracer IgG occurred at the perineurium and within endoneurial blood vessels, although the endoneurium itself was spared because of the presence of the blood-nerve barrier. Because of the small size of the biotin ligand and the non-denaturing method of labeling proteins, our mode of application of the avidin-biotin system appears suitable for tracer studies.

Animals↗
PubMed1985

An immunohistochemical and electron-microscopic study of vascular endothelial cells in vocal fold polyps.

Gelatinous and telangiectatic types can be differentiated among the human vocal fold polyps. Telangiectatic polyps are characterized by eosinophilic deposits consisting of fibrin and cellular blood constituents. Labyrinthine vascular channels are characteristic of these polyps, and are partially or completely lined by a single layer of flat cells. Using electron microscopy and immunohistochemical stainings (antibodies against factor VIII-related antigen, Ulex europaeus I lectin, and antibodies against lysozyme), we found that the lining cells are true vascular endothelial cells and are not organizing histiocytic cells that are arranged in an endothelial-like pattern.

Antigens↗
PubMed1985

Affinity cytochemistry of vascular endothelia in brain tumors by biotinylated Ulex europaeus type I lectin (UEA I).

The vascularization of 50 tumors of the central nervous system (CNS) including 17 meningiomas, 25 neuroectodermal tumors, i.e., astrocytomas, oligodendrogliomas, mixed gliomas, glioblastomas, medulloblastomas, seven metastatic carcinomas, and one malignant hemangioendothelioma were investigated using biotinylated Ulex europaeus type I lectin (UEA I) in an indirect avidinbiotin-peroxidase procedure. The cytochemical staining pattern of UEA I on paraffin sections was compared with that of biotinylated Dolichos biflorus lectin (DBA), and with the immunocytochemical staining of factor VIII related antigen (F VIII/RAG) by polyclonal antisera using the PAP technique. UEA I visualized the endothelia of blood vessels with equal intensity, sensitivity, and reliability in normal brain and in tumor tissue with neovascularization. While large, medium, and small vessels were equally well demonstrated by UEA I and antibodies against FVIII/RAG, capillaries and endothelial sprouts were stained more consistently and intensely by UEA I. No reliable cytochemical staining could be obtained by DBA regardless of tissue or cell type investigated. It is concluded that UEA I is a highly useful cytochemical marker for the identification of vascular endothelia in paraffin sections of human brain tumors.

Antibodies↗
PubMed1985

The mouse blood-brain barrier and blood-nerve barrier for IgG: a tracer study by use of the avidin-biotin system.

To study the permeability of the blood-brain barrier (BBB) and the blood-nerve barrier (BNB) for immunoglobulin G (IgG) we adapted the avidin-biotin system for postembedding demonstration of the tracer IgG in the central and peripheral nervous system (CNS, PNS). Normal mouse and human IgG were biotinylated and injected daily into the intraperitoneal (i.p.) space of adult BDF1 mice. After 24h, IgG was detected in blood vessels and in the interstitium of various organs, but staining was restricted to the dura mater in the CNS, to the spinal ganglia, and to the perineurium of peripheral nerves. After 4 days, IgG was also present in the endoneurial connective tissue of peripheral nerves, while the brain, spinal cord, and spinal roots remained free of IgG. Our results show a partial permeability of the normal mouse BNB for homologous and heterologous IgG.

Animals↗
PubMed1985

Immunocytochemical studies of serum proteins and immunoglobulins in human sural nerve biopsies.

Post-embedding immunocytochemical studies on immunoglobulins (Ig) and other serum proteins were carried out on 38 human sural nerve biopsies using the PAP method. In addition to toxic, hereditary, metabolic, dysproteinemic, and vasculitic-neuritic neuropathies, morphologically normal sural nerves were included as controls. The intensity of the immunocytochemical reactions was strong for proteins, such as IgG, the light chains of Igs, and albumin, but weak or absent for others like complement component C3, IgA, ceruloplasmin, and alpha-1-antitrypsin (AAT) in normal nerve biopsies and in all pathologic groups. IgG, the light chains of immunoglobulins, and albumin could readily be detected in perineurium, endoneurial interstitium, and blood vessel walls. IgM, C3, and beta-lipoprotein (BLP) were largely confined to the walls of blood vessels and perineurium, thus indicating that they do not penetrate the blood nerve barrier. Only in a few cases, in vasculitic-neuritic and dysproteinemic neuropathies, staining of the endoneurial interstitium for IgM and C3 was observed. Increased staining for the corresponding heavy or light chains was not detected in the endoneurium in any of the neuropathies associated with gammopathy. The results stress that PAP immunocytochemistry is suitable for studying the blood-nerve barrier (BNB) and provides new aspects to the concept of the BNB with respect to the steady state of serum proteins between endoneurial and vascular spaces. It is suggested that, in addition to serum concentration and molecular weight of serum proteins, the permeability of the BNB is influenced by other yet undefined factors.

Adolescent↗
PubMed1985

[Acute course of Leigh syndrome with hypertrophic cardiomyopathy in a female infant].

A female infant already as a newborn progressively developed nutritional disturbances, metabolic acidosis, muscular hypotension and other neurologic changes, and on its 20th day of life suffered from an acute cardiac and respiratory insufficiency due to pericardial effusions causing cardiac tamponade. In spite of intensive care including mechanical ventilation the child died on the 58th day of life. Cardiac changes and cranial CT-scans are demonstrated. The characteristic symptomatology as well as blood chemistry led to the tentative diagnosis of Leigh's disease. Postmortem examination confirmed this diagnosis.

Acidosis↗
PubMed1984

Adult-onset mixed myopathy with nemaline rods, minicores, and central cores: a muscle disorder mimicking polymyositis.

A woman, aged 75 years, presented with a 15-year history of progressive, generalized, painful muscle weakness and wasting. Clinical and laboratory investigation revealed a sporadic muscle disorder. Muscle biopsy showed a mixed pattern of nemaline myopathy with minicores and central cores and severe atrophy of type-1 and type-2 fibers. A trial of immunosuppressive treatment did not improve her condition, which clinically mimicked chronic progressive polymyositis. Mixed myofibrillar myopathies of this type have so far only been described among the group of congenital myopathies.

Age Factors↗
PubMed1984

Congenital Leigh's disease: panencephalomyelopathy and peripheral neuropathy.

A dystrophic newborn girl (38th week of gestation) presented as a floppy infant with relapsing episodes of lactic acidosis and progressive cerebral deterioration. She died after serious apnoea at the age of 8 weeks. Neuropathological examination demonstrated widespread changes of Leigh's subacute polioencephalomyelopathy affecting the cerebral cortex, basal ganglia, mesencephalon and spinal cord. In addition, there was severe leukoencephalopathy of the cerebral hemispheres with sudanophilic tissue degregation, advanced axonal loss and reactive astrocytic gliosis. There was marked demyelination of the sciatic nerves. Electron-microscopical examination of the hypertrophic heart revealed pathological mitochondria with tubular inclusions suggestive of primary mitochondrial cardiomyopathy. Similar mitochondrial changes were not detected in the CNS and PNS. The complex of neuropathological alterations in this case is nevertheless consistent with a congenital variant of Leigh's disease.

Brain↗
PubMedDate not supplied

Variability of the regional cerebral blood flow pattern studied with [11C]-fluoromethane and position emission tomography (PET).

The mean regional cerebral blood flow (rCBF) pattern measured with [11C]-fluoromethane and positron emission tomography (PET) in 26 healthy subjects was heterogenous throughout the brain showing the highest rCBF in the medial prefrontal cortex and the lowest rCBF in the inferior temporal cortex. Right/left asymmetry of the mean rCBF was not significant. The variability of the rCBF pattern was assessed by dividing the subjects into one group of naive subjects and one group of subjects who had habituated to the scanning procedure. Naive subjects had a significantly higher mean rCBF (p less than 0.05) in defined areas of the higher order association cortices predominantly in the right cerebral hemisphere, but a virtually identical mean rCBF in the primary cortical input and output areas. These findings suggest a raised level of mental activity in subjects undergoing the first PET measurement.

Adult↗
PubMedDate not supplied

Identification of task-specific rCBF changes in individual subjects: validation and application for PET.

OBJECTIVE: A method for identification and quantitative evaluation of task-specific changes of the regional cerebral blood flow (rCBF) measured with PET in activation studies of individual subjects is presented. The method is based on the statistical distributions of the quantitative and spatial information of regions of interest in rCBF subtraction images. METHODS: For validation, a cylindrical phantom of 20 cm diameter containing six spheres of 10-30 mm in diameter was used. The spheres representing the specific signals were filled with 18F, while one-tenth of this activity concentration was filled into the background compartment of the phantom representing "noise." Of a sequence of dynamically recorded frames, subtraction images with different signal-to-noise ratios were calculated. RESULTS: In these subtraction images, our method allowed us to identify the larger spheres accurately and to quantify the signals. Comparison with t map analysis in averaged subtraction images revealed a high correspondence with the results obtained by our method in individual subtraction images. Based on this phantom validation, the method was applied for mapping of rCBF changes in humans. The rCBF was measured with [15O]butanol in four subjects during unilateral somatosensory discrimination and during rest. CONCLUSION: The method proved to be capable of identifying task-specific rCBF changes in the contralateral motor, premotor, and sensory cortex accurately and with high quantitative and anatomical precision in each subject.

Adult↗