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Biomedical subjects

W Wechsler

Publications and source records attributed to W Wechsler.

At least 55 records · Page 3Linked to original sources
PubMed1988

Emery-Dreifuss muscular dystrophy: disease spectrum and differential diagnosis.

We report six patients with Emery-Dreifuss muscular dystrophy (EDMD) and four patients including one female with EDMD phenotype (EDMDP). This series includes one sporadic case who had previously been reported in this journal under the diagnosis of "rigid spine syndrome" in 1977. Time of observation ranged from three to ten years. Detailed cardiological assessment was performed in all patients, skeletal muscle biopsies were obtained from 9 out of 10 and cardiac muscle biopsies from 2 out of 10 patients. One patient showed evidence of cardiomyopathy in the absence of clinically apparent neuromuscular disease and one sibling of another EDMD patient reportedly had a similar combination of symptoms which, to our knowledge, has not yet been reported. Cardiac involvement was found to consist of four independent, albeit often combined features: 1) impairment of impulse generating cells; 2) conduction defects with atrial preponderance; 3) increased atrial and ventricular heterotopia; and 4) functional impairment of ventricular myocardium. Ventricular involvement as apparent from ventricular heterotopia, abnormal enddiastolic diameter, decrease of contractility and/or morphological evidence of ventricular myocardial disease was found in 7 out of 10 patients and confirmed by myocardial histopathology in two EDMD patients. In one myocardial biopsy extensive accumulations of intermediate filaments were observed, a rare finding, which has not been linked to EDMD before. Skeletal muscle biopsies showed evidence of myopathy throughout but several equivocal features such as fibre type grouping in EDMD and fibre type disproportion in EDMDP were also observed. The variability of clinical manifestation of both cardiac and neuromuscular disease encompassed a broader spectrum than apparent from the literature. The consequences for the inherent differential diagnosis are discussed.

Adolescent↗
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

Distribution of anti-Leu-7, anti-Leu-11a and anti-Leu-M1 immunoreactivity in the brain of the adult rat.

This study reports a specific cross-reactivity of the three anti-human-hematopoietic-cell monoclonal antibodies, anti-Leu-7 (HNK-1), anti-Leu-11a (NKP-15), and anti-Leu-M1 (MMA), with different epitopes in the brain of the adult rat. The distribution of these epitopes in rat brain is determined by means of immunohistochemistry in paraffin-embedded frontal serial sections. The reaction pattern of anti-Leu-11a monoclonal antibody is very similar to that of polyclonal antibodies against the myelin basic protein. Both antisera give a specific reaction with myelinated fibers. Immunoreaction products with the anti-Leu-7 monoclonal antibody are found as diffuse, mostly punctiform material in the neuropil and even more evident as small granules coating the cell surface of many neurons. In the white matter anti-Leu-7 reveals a moderate reactivity, which occurs predominantly as spots and fine-stranded material within the myelinated fiber tracts. Anti-Leu-M1 immunoreactivity is present between myelinated fiber bundles of the white matter, where it has a reticulate appearance, and as fine-granulated material within the grey matter of the cortex and the nuclei. The characteristic feature in the grey matter is that of irregularly shaped immunopositive plaques, which are often located around small blood vessels. The cytoplasm of glial and neuronal cells appeared negative with this MAB. The exact topographical distribution of the Leu-7 and Leu-M1 epitopes throughout the rat brain is described. The present hypotheses concerning the nature of this shared antigenicity between hematopoietic cells and nervous tissue are discussed.

Animals↗
PubMed1987

Magnetic resonance imaging of colloid cysts of the third ventricle.

Two cases of colloid cyst of the third ventricle are reported. Their computed tomographic (CT), magnetic resonance (MR) and neuropathological features are presented. The MR findings were different in the two cases for reasons not yet fully explained, full biochemical and biophysical analyses of the cyst contents not being available. Neuropathologically, the only significant difference was the abundant presence of cholesterin crystals in the colloid of case 1 and their absence in case 2. One of our cases is also peculiar from a CT point of view, since it was primarily hypodense and did not enhance on intravenous contrast administration.

Brain Diseases↗
PubMed1987

Differential expression of glial- and neuronal-associated antigens in human tumors of the central and peripheral nervous system.

The immunoreactivity of a panel of poly- and monoclonal antibodies raised against different glial and neuronal antigens was investigated in paraffin-embedded specimens of 116 human tumors of the central and peripheral nervous system. We used antibodies against the HNK-1 epitope, which is shared between natural killer cells and the nervous system, glial fibrillary acidic protein (GFAP), vimentin, neurofilaments, S-100 protein, neuron-specific enolase (NSE) and myelin basic protein (MBP). HNK-1 immunoreactivity was detectable in nearly all neuroectodermal tumors. Especially in those derived from the neuroepithelium, which include the various types of gliomas, we observed a strong staining with this antibody. The only exceptions were the choroid plexus papillomas and individual ependymomas. In tumors derived from the neural crest HNK-1 reactivity was more variable and less intense. In other tumors of the nervous system HNK-1 was not detectable, except for two out of four malignant lymphomas. In addition to its reactivity with human lymphocytes HNK-1, therefore, seems to be a useful 'marker' for neurogenic tumors in general. GFAP expression was prominent in all astrocytomas and the astrocytic cells within mixed gliomas and gangliogliomas. Immunoreactivity was more variable in glioblastomas and ependymomas, while only isolated GFAP-positive cells were present in oligodendrogliomas, medulloblastomas, one plexus papilloma, and some neurinomas. Vimentin immunoreactivity was found in tumor cells of nearly all tumors of the central nervous system with the exception of oligodendrogliomas, most plexus papillomas, neuronal tumors and most medulloblastomas.

Antibodies, Monoclonal↗
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

The influence of magnetic resonance tomography on diagnosis and therapy in patients with intracranial manifestation of neurofibromatosis (Recklinghausen disease).

Recent research into the natural course of neurofibromatosis has revealed an outstandingly high proportion of central nervous system malignancies as well as cancers of various other organs. Due to the lack of ionizing radiation, the extraordinary reconstruction in the frontal and parasaggital planes as well as the diagnosis of intracanalicular acoustic neurinomas and intraorbital tumors, magnetic resonance tomography (MRT) is indicated for control of patients with neurofibromatosis.

Adolescent↗
PubMed1987

Neurological manifestations in three German children with AIDS.

We report the neurological findings in two children with AIDS and one child with lesser AIDS. The first patient developed acute encephalopathy 37 months after having received a blood transfusion from a HTLV-III positive donor. CCT showed ring-enhancement and hypodense lesions with homogenous enhancement. Autopsy revealed CNS toxoplasmosis. The second child with AIDS, born to an iv drug-addicted mother, had one seizure at four months of age, but other neurologic signs were absent. She died of pneumonia due to Pneumocystis carinii at seven months of age. Postmortem examination of the brain revealed extensive nerve cell damage in the cerebral cortex and cerebellum, probably due to terminal hypoxemia and not AIDS-related. In both children clinical features of childhood AIDS like failure to thrive, lymphadenopathy, oral thrush and chronic pulmonary infiltrates were absent. The hallmark of the third child's clinical course was a progressive loss of psychomotor abilities with onset of the neurological symptoms nine months before other signs of AIDS occurred. AIDS should be suspected or excluded in children at increased risk for AIDS presenting with either acquired atypical CNS infection or unexplained developmental regression, even in the absence of other clinical symptoms of pediatric AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Subcapsular renal transplantation of neurogenic tumors and tumor spheroids. A comparative study of RN6 and RG2 tumor clones after syngeneic and allogeneic transplantation.

The subcapsular renal transplantation tumor model was explored to standardize the growth of rat RN6 neurinoma and RG2 glioma nitrosourea-induced clonal cell lines in syngeneic and allogeneic systems. Growth of RN6 and RG2 tumor spheroids was compared with that of solid subcutaneous tumor pieces transplanted under the renal capsule. Two morphometrical methods were applied to evaluate growth rates. Tumor specimens were examined histologically with regard to their morphology, extent of immune reactions, and development of tumor necroses. The take rate was 98%. In the syngeneic system linear progressive tumor growth was found, while in preirradiated allogeneic rats this was only the case up to 21 to 25 days post transplantation (p.t.). Strong rejection reactions in the allogeneic RN6 tumors were noted from 4 to 7 days p.t. resulting in total tumor rejection after 10 to 14 days. Both kinds of tumors, especially in the first days of growth, were characterized by strong desmoplastic reaction with rich reticulin fiber formation. However, after 10 days, in the center of RG2 subcapsular renal tumors (SRT) this kind of reaction was found only in the vicinity of tumor vessels, while RN6 SRT demonstrated reticulin fibers around tumor cells in all cases studied. The transplantation experiments revealed that the malignant RN6 and RG2 spheroids represent a suitable tool to study three-dimensional early tumor growth in both in vivo and in vitro cultures. The model of spheroid transplantation under the renal capsule is simple to handle and well reproducible. Compared with subcutaneous tumors the SRT model has advantages in early stages of tumor growth because the tumors are clearly visible grossly and can be easily submitted to adequate morphometry, indicating that this model may be suitable for experimental chemotherapy and radiotherapy studies.

Animals↗
PubMed1986

Binding specificity of two monoclonal antiglioma antibodies: immunocytochemical studies using a new tissue embedding technique.

The binding specificities of two monoclonal antiglioma antibodies (MAB) derived from hybrids GE2 and BF7 (Schnegg et al. 1981) were tested by indirect immunofluorescence (IF) and two immunoperoxidase (IP) methods. Studies were done on biopsies from 33 human CNS tumors, human derived glioma cells, and N-ethylnitrosourea-induced neurogenic rat cells in culture. The immunohistochemical reactions of MAB were investigated in snap-frozen tumor material, conventionally paraffin-embedded material, and tumors embedded in formol sucrose/gum sucrose/paraffin (FSGSP) by the new tissue processing technique of Bolton and Mesnard (1982), which preserves and enhances the antigenicity of tissues. The FSGSP processing offered a better immunocytochemical staining with MAB as compared to cryostat material, while the conventionally embedded paraffin sections of tumors did not stain at all. The binding of MAB revealed an affinity to both glial tumor cells and normal astrocytes. The techniques described are suitable for the identification of an astrocytic subpopulation within gliomas, and may improve the understaining of antigen expression in various stages of astrocytic dedifferentiation.

Animals↗
PubMed1986

Regional metabolism of experimental brain tumors.

Experimental brain tumors were produced in rats by stereotactical implantation of various neoplastic cell lines (RG 2, RG1 2.2, G 13/11, F 98, RN 6, B 104, and E 367). Using autoradiographic, bioluminescence, and fluoroscopic methods, the following regional hemodynamic and metabolic parameters were measured on intact brain sections: blood flow, glucose utilization, pH, and the tissue content of ATP, glucose, and lactate. Tumors exhibited a considerable diversity of regional blood flow and metabolic activity which did not correlate with the implanted cell line, location, or growth pattern. In solid regions of tumors the most consistent finding was a higher glucose utilization rate, a higher lactate, and a higher pH than in the surrounding brain tissue. Tumor ATP was slightly higher and glucose slightly lower than in the brain. In large spherical tumors a declining gradient of blood flow, glucose, and ATP from the periphery to the central parts was frequently observed, the decline being more pronounced for glucose than for ATP. In regions with high ATP tissue pH was usually higher than in the brain, but it decreased in areas in which ATP was depleted. The results obtained indicate that tumors are able to control tissue pH despite increased glycolysis and lactate production, as long as the energy state is not impaired. The mechanisms of pH regulation, therefore, have to be considered for establishing therapeutic procedures which intend to lower tumor pH for induction of tissue necrosis.

Adenosine Triphosphate↗
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

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

RG2 glioma growth in rat cerebellum after subdural implantation.

The nitrosourea-induced rat glioma clone RG2 was tested for its capacity to form multicellular tumor spheroids (MTS's). Resulting spheroids were investigated by light and electron microscopy with regard to their proliferation patterns and morphological features. Using microsurgical techniques and avoiding mechanical injury of the brain tissue, the authors successfully transplanted avascular MTS's under the dura of the cerebellum, above the vermis, in 43 adult syngeneic Fischer CD rats. The rate of tumor establishment was 93%, and the tumors that were solid and spheroid in shape grew exponentially. Neovascularization could be observed at 3 days after implantation, and invasion of the cerebellum occurred by 3 to 5 days. Neurological deterioration, including ataxia, impairment of walking, and apathy, could be observed after 10 days. The mean survival time was approximately 16 days. The subdural cerebellar tumors were studied by histological techniques, and two morphometric methods were applied to check the growth of implanted spheroids. All tumors were deeply stained with the Evans blue dye-albumin complex, demonstrating disturbance of the blood-brain barrier. The easy accessibility of the cerebellar vermis in rats, the microsurgical implantation of glioma spheroids under the dura avoiding nerve tissue disruption, and the high percentage of reproducible establishment of tumors favor this experimental brain-tumor model. This should be an excellent model for study of experimental therapies.

Animals↗
PubMed1986

[Application of renal subcapsular assay to rat malignant brain tumor].

As a rapid screening method for testing chemotherapeutic agents against human tumor explants, renal subcapsular assay has been established by Bogden et al (1978). The authors investigated the effectiveness of the technique of Bogden for rat glioma. Preselected 1 mm3 fragments of viable tumor tissue of rat (CDF) were implanted under the renal capsule of normal immunocompetent rats. Then initial and final tumor sizes (formula; see text) were measured in situ with an oculometer inserted into a surgical microscope, and evaluated the changes of tumor sizes. The experiments were divided into three groups. The first group was that tumor pieces of rat (CDF) were implanted under the renal capsule of the syngenetic rats (CDF). Non-irradiated and preirradiated (400 rad) heterogenetic rats (Wistar) were used as the second and third groups. The explanted tumor pieces grew rapidly in the first group (syngenetic rats). On the other hand, poor growth of the second group (non-irradiated heterogenetic rats) was seen within 7 days after implantation, and rejected completely until 15 days after implantation. Explanted tumor pieces in the third group (pre-irradiated heterogenetic rats), however, grew enough big, though the change of tumor sizes was less than that of the first group. Histological examination was also performed. In the first and third group, proliferation of glioma cells was remarkable under the renal capsule, and neovascularization in the explanted tumor tissue was provided from the capsule, first, and then parenchym of the kidney. Even necrosis and hemorrhage were seen in the tumor tissue 15 days after implantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

[Responsiveness of brain tumors to chemotherapeutic agents in the subrenal capsule assay].

The 6-day subrenal capsule assay was used to determine chemotherapeutic sensitivities of brain tumors. Twenty-nine brain tumors were obtained at the time of surgical resection. A minced tumor fragment (1-mm cube) was implanted under the renal capsule of 5- to 8- week-old normal female ddY mice. Each fragment was measured at two diameters using ocular micrometer unit (10 omu = 1.0 mm). The animals were randomized, usually 5 to 7 per group, and treated with anticancer drugs on day 1 through 5. On day 6, the mice were killed. The kidney was exteriorized and the tumor was again measured. The change in tumor size was obtained for each animal by ratio of the final tumor size/the initial tumor size. Sensitivities of tumors to anticancer agents were determined by comparing differences in mean values of the change in tumor size between control and treated group. Twenty-seven out of 29 specimens (93%) were submitted to evaluable assay. The response rate of 11 malignant gliomas (grade 3 and 4) was 44% and that to anticancer drugs tested were as follow: 5-FU 78%, ACNU and CPA 50%, VCR 40%, CDDP 36%. The response rate of 3 medulloblastomas was 36%: MTX 67%, CPA 50%, ACNU and CDDP 33%. That of two low-grade gliomas (grade 2) was 29%, while that of 4 malignant brain tumors (2 metastasis, chordoma, malignant fibrous histiocytoma) was 60%. Four neurinomas and 3 meningiomas were not sensitive to Tamoxifen and none were determined for estrogen receptor. In histological analysis, the transplanted tumor retained similar characteristics to the original tumor in the cases of neurinomas, meningiomas and some gliomas. Lymphocytic infiltration was observed in many cases. In the cases of metastasis (adenocarcinomas), considerable mesenchymation and lymphocytic infiltration was observed, tumor cells were reduced in number with poor preservation. Clinical response in 9 cases treated with sensitive drugs were 1 complete response, 2 partial response, 5 stable and 1 progressive disease in CT examination. The subrenal capsule assay is therefore considered to be very useful for determining suitable chemotherapeutic agents for brain tumors.

Animals↗