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Biomedical subjects

D Schiffer

Publications and source records attributed to D Schiffer.

At least 109 records · Page 6Linked to original sources
PubMed1990

Chondroitin 4-sulfate proteoglycan forms an extracellular network in human and rat central nervous system.

Chondroitin 4-sulfate proteoglycan (C4S-PG) was localized both in rat and human central nervous system (CNS) by monoclonal and polyclonal antisera recognizing the 4-sulfate disaccharide (C4S). In the rat the whole CNS was studied in serial coronal sections. A positive extracellular meshwork was observed both in white and grey matters. In the white matter (WM) C4S-PG formed a network around myelinated axons, sparing myelin sheaths and axoplasms. The neuropil of the grey matter (GM) showed a positive meshwork constituted by delicate intermingling filaments. The cytoplasms of neuronal, glial and endothelial cells were negative. Stronger straining than in the neuropil was observed around the soma and the proximal part of the cell processes of some neurons located in the cortex, in the deep cerebellar nuclei and in some other CNS nuclei. A similar pattern was also observed in human CNS, the only difference being a smaller amount of cortical neurons surrounded by a rim of C4S-PG. This study shows that a PG bearing C4S disaccharide is located extracellularly in the rodent and human CNS and that C4S disaccharides can be present in different types of CNS proteoglycans (PGs).

Aged↗
PubMed1990

Friedreich's ataxia: a descriptive epidemiological study in an Italian population.

All the cases of Friedreich's ataxia (FA) diagnosed between 1945 through 1984 among residents of a defined area of northwestern Italy were ascertained (N = 59). Cases were diagnosed according to the criteria of the "Quebec Cooperative Study on Friedreich's Ataxia (QCSFA)" with minor modifications. We identified 39 families with 47 probands and 12 secondary cases. Therefore ascertainment probability was 80%. Male to female ratio was 1:1. Pedigrees were compatible with autosomal recessive inheritance. Segregation ratio was 0.28 with both Weinberg's method and the "singles" method (under incomplete ascertainment). Point prevalence ratio was 1.2/100,000 population. Birth incidence rate was 1/36,000 live births. Gene frequency was estimated to be 1/191. The ratio of first-cousin marriages observed among parents of FA patients (3%) was lower than expected from Dahlberg's formula (8%). This finding is not compatible with the hypothesis of genetic heterogeneity for FA.

Adolescent↗
PubMed1989

Brain tumors of childhood: nosological and diagnostic problems.

Brain tumors containing undifferentiated cells were selected from a series of 504 childhood brain tumors; 117 were analyzed. Most tumors were medulloblastomas, followed by cerebral neuroblastomas, pineocytomas-blastomas, ependymoblastomas, and polar spongioblastomas. Of each oncotype, the main histological features were evaluated, including differentiation and the most important prognostic factors. The terminology and different tumor entities are discussed in light of the recent PNET system. The usefulness of its application is evaluated in relation to prognosis.

Brain Neoplasms↗
PubMed1989

The vascular response to tumor infiltration in malignant gliomas. Morphometric and reconstruction study.

Neo-vascularization and endothelial hyperplasia have been shown to be very active in malignant gliomas. In this contribution the vascularization of the cortex infiltrated by malignant gliomas is morphometrically studied and the endothelial proliferations are immunohistochemically investigated and reconstructed by a three-dimensional computer-assisted procedure. Vessel density increases after tumor infiltration in some cases only. The diameter of vessels increases and so does the number of nuclei/vessel after the complete invasion of the cortex when vascular glomeruli develop. In completely infiltrated cortex with development of glomeruli and circumscribed necroses, vessel density is very low. No neoformation of vessels takes place before the complete infiltration of the cortex by the tumor. The hyperplastic formations, usually arranged parallel to the deep or outer cortical layers, take origin from the radially penetrating vessels from the meninges and their lateral branching. The hyperplasia deforms the vascular network, making it often inadequate to supply tumor cells. Immunohistochemically, the cells composing the hyperplastic structures are variably positive for factor VIII/RAg and, at a lesser extent, for alpha-smooth muscle actin. The poorness of the vascular network in many instances of completely infiltrated cortex is responsible for the development of circumscribed necroses.

Brain Neoplasms↗
PubMed1989

Epidemiology of motor neuron disease in two Italian provinces. Analysis of secular trend and geographic distribution.

Incidence and prevalence rates of motor neuron disease in two Italian provinces (Asti and Cuneo, Piedmont region) in the period 1971 through 1985 were estimated. The data were omogeneous in the investigated area, but an increasing incidence of the disease during the period studied was found, particularly in older age groups and in females. An increasing trend in mean age of onset of symptoms was also found.

Aged↗
PubMed1989

Prognostic factors in well-differentiated cerebral astrocytomas in the adult.

Eighty-five "well-differentiated" astrocytomas in adults (age, greater than or equal to 18 years), operated on between 1950 and 1982, were retrospectively reviewed. The pilocytic variant was not included. Twenty-four clinical and 8 histological factors were analyzed to investigate their importance in predicting length of survival. Multivariate analysis showed that the following variables were correlated with survival time (P less than 0.01): extent of surgical removal, altered consciousness during preoperative examination, focal deficit as presenting symptom, performance status (Karnofsky rating) after surgery, and vessel size in the surgical specimen. Total removal of the tumor was related to a higher 5-year survival rate (51%) than subtotal removal (23.5%), and none of the patients with partial removal survived more than 5 years. Postoperative radiotherapy (40-55 Gy) improved only the 1- and 3-year survival rates. Based on the significant factors provided by multivariate analysis, a score was developed to detect subgroups with different prognoses. Median survival time ranged from 383 days for patients with a score greater than or equal to 2.5 to 1,533 days for those with a score less than 0.5; no patient with a score greater than or equal to 1.5 survived more than 10 years. The percentage of recurring astrocytomas that showed anaplastic areas in the second biopsy specimen was 79%. Total surgical removal is the most important factor in the management of well-differentiated astrocytomas, whereas the efficacy of postoperative radiotherapy still needs to be confirmed by prospective and randomized studies. The rationale for treating incompletely resected astrocytomas with radiation therapy could lie in the high incidence of malignant transformation.

Adolescent↗
PubMed1989

Biochemical, histochemical and immunohistochemical study of glycosaminoglycans in human meningiomas.

The localization and quantitation of glycosaminoglycans classes (GAGs) were studied in human meningiomas. Meningiomas presented high amounts of these compounds and electrophoretic separation revealed that they were 90% sulphated. The Alcian method and a polyclonal antiserum against chondroitin sulphate were used to localize the different GAGs in tissue sections. Quantitative and qualitative differences and different tissue distributions of GAGs were observed among transitional, syncytial and fibroblastic meningiomas. Syncytial meningiomas presented the lowest amount of GAGs and the immuno- and histochemical studies showed that they were located only in vessels and connectival trabeculae. Transitional meningiomas contained the highest concentration of GAGs; the percentage of the different GAG classes was similar to that observed in the syncytial oncotype indicating a quantitative but not qualitative difference between the two oncotypes. The high amount of GAGs in transitional meningiomas was attribute to the whorls, the structures stained by the histochemical and immunohistochemical techniques. The tumoral parenchyma of these two oncotypes was negative. On the contrary, fibroblastic meningiomas showed a fine meshwork among tumoral cells containing chondroitin sulphate and heparan sulphate. Biochemical data were consistent with the histochemical and immunohistochemical findings revealing a high percentage of chondroitin sulphate and heparan sulphate in fibroblastic meningiomas. This study suggests that the three meningioma types have different abilities to produce extracellular matrix components.

Glycosaminoglycans↗
PubMed1988

Reactive astrocytes in the morphologic composition of peripheral areas of gliomas.

The participation of reactive astrocytes in the morphologic composition of peripheral areas of 25 gliomas was investigated. Reactive astrocytes were studied by the immunohistochemical demonstration of glial fibrillary acidic protein and vimentin. Reactive astrocytes were more abundant around malignant gliomas than around well-differentiated astrocytomas. They underwent modifications when entrapped within the tumor proliferation and became indistinguishable from tumor astrocytes. Mitoses occurred in both types of cells. Reactive astrocytes did participate in the cell composition of gliomas. They might have contributed to tumor growth. Practically, their occurrence might lead to an erroneous diagnosis when small fragments of tissue are examined.

Astrocytes↗
PubMed1988

Prognostic value of histologic factors in adult cerebral astrocytoma.

Surgical specimens from 165 adults with cerebral astrocytoma were reviewed to establish the prognostic value of histologic factors when studied both individually and in combination. Glioblastomas were excluded. Nine morphologic parameters and 25 clinicotherapeutic factors were correlated with survival. Cell density, endothelial hyperplasia, number of mitoses X 10 high-power field (HPF), and vessel frequency appeared to be highly significant prognostic factors (P less than 0.001). Nuclear polymorphism, microcysts, and vessel size were significant moderately (P less than 0.01). Microcysts, vessel size, endothelial hyperplasia, and number of mitoses X 10 HPF remained significant statistically after a multivariate analysis that also included clinicotherapeutic factors. Survival was similar for astrocytomas with "extensive malignancy" and astrocytomas with only "slight and localized malignancy." Multivariate analysis showed that the presence or absence of malignancy was more important prognostically than the clinical variables (i.e., postoperative Karnofsky status or extent of surgical removal).

Adult↗
PubMed1988

Motor neuron disease and malignancies: results of a population-based study.

Eight cases of malignancies with concurrent motor neuron disease (MND), derived from an unselected population representing all cases of MND diagnosed during a 15-year period in two Italian provinces, were studied to verify the existence of paraneoplastic forms of the disease. No statistically significant association between the two diseases was found. Therefore, from our findings the occurrence of a neoplasm in a patient affected by MND can be considered a chance association.

Adult↗
PubMed1988

A follow-up study of 60 cases of chronic spinal muscular atrophy.

60 cases of chronic spinal muscular atrophy (CSMA) were followed-up for a period varying from 5 to 40 years. The neuromuscular impairment was evaluated by Norris' ALS score, both at the time of last examination and retrospectively at the time of diagnosis. Age at onset of symptoms was the most important factor in the progression of the neuromuscular damage. Monomelic or asymmetric location of symptoms at the time of diagnosis and duration of the disease were not significantly correlated to the worsening of ALS score.

Adult↗
PubMed1988

Glutamate dehydrogenase (GDH) deficiency in different types of progressive hereditary cerebellar ataxia.

Leukocyte glutamate dehydrogenase (GDH) was studied in 29 patients affected by progressive cerebellar ataxia (PCA) and in 20 healthy controls. Eight GDH-deficient patients, with GDH activity 2 SD below mean value of controls, were identified. GDH deficiency did not identify a subgroup of PCA by characteristic pattern of inheritance and/or age of onset of disease. However, the GDH-deficient patients presented more neurological signs than non-GDH-deficient patients. A significant correlation was observed between GDH deficiency and the presence of extrapyramidal signs, supranuclear palsy, absence of osteotendineal reflexes and neurogenic electromyographical findings.

Adolescent↗
PubMed1988

Post-poliomyelitic motor neuron disease. Clinical aspects and its relation to typical motor neuron disease.

Eighteen cases of post-poliomyelitic motor neuron disease (PPMND) were found in a series of 869 subjects affected by motor neuron disease (MND). The mean age of onset of acute anterior poliomyelitis (AAP) was 43.6 months. The mean age of onset of MND was 45.9 years. No case had a bulbar onset and hyperreflexia was found in only 2 subjects, one of them having also bilateral extensor plantar response. The survival curve showed a better course of these cases, compared to typical MND (TMND). The present study seems to indicate that PPMND and TMND are different diseases.

Adult↗
PubMed1988

Free cytoplasmic Ca++ at rest and after cholinergic stimulus is increased in cultured muscle cells from Duchenne muscular dystrophy patients.

We used a fluorescent dye, quin 2, to measure intracellular free calcium ([Ca++]i) in cultured skeletal muscle cells and skin fibroblasts from five Duchenne muscular dystrophy (DMD) patients and from five controls. We observed an enhanced [Ca++]i level, at rest and after acetylcholine (ACh) stimulation, in DMD muscle cells, but we did not detect any difference between DMD and normal skin fibroblasts. The abnormally higher [Ca++]i transient induced by ACh suggests that it plays a critical role in muscle degeneration. The skin fibroblast results suggests that there is no generalized membrane defect.

Acetylcholine↗
PubMed1988

Friedreich's disease: survival analysis in an Italian population.

This investigation is the first population-based study of survival in Friedreich's disease (FD). All cases of FD diagnosed between 1945 through 1984 among residents of a defined area of northwestern Italy were ascertained (N = 58). These patients were followed to death or to December 31, 1984 (whichever came first) to determine the patterns of survival. The 10-, 20-, and 30-year survival rates were respectively 96%, 80%, and 61%, suggesting a better prognosis than previously reported. Survival of FD patients was poorer than expected from the general population. Survival for males was poorer than for females even after adjustment for expected survival. Age of onset was not a significant prognostic factor. Survival for patients diagnosed in 1960 or later was better than for those diagnosed before 1960; however, the difference was not statistically significant.

Adolescent↗
PubMed1987

Primary lymphomas of the brain: a clinico-pathologic review of 37 cases.

The clinico-pathologic data of 37 primary lymphomas of the brain were retrospectively reviewed. The tumors were classified according to the Kiel classification and the Working Formulation System. They represented 1.02% of all primary intracranial tumors of our series. The radiologic prediction appeared to be difficult: the suspicion was maximal when the absence of pathologic vessels at angiography occurred in a meningioma-like lesion at CT. Median survival was 4.53 months in the 16 cases who underwent surgery only versus 25.7 months in the 8 cases operated and irradiated with 40-60 Gy (p less than 0.01). The prognosis of lymphomas of the CNS, even if radioresponsive tumors, remains poor. Most patients relapse after treatment, most often locally in the brain, with a variable frequency of spinal or systemic localization.

Adolescent↗