PubMed Health⌕ Search

Biomedical subjects

R L Schelper

Publications and source records attributed to R L Schelper.

43 records · Page 3Linked to original sources
PubMed1984

Orbital malignant melanoma and oculodermal melanocytosis: report of two cases and review of the literature.

Oculodermal melanocytosis is a congenital melanoblastic hamartoma affecting ocular tissues and facial skin. It is seen more commonly in oriental and black patients. Malignant degeneration, once believed to be rare in this syndrome, occurs in 4.6% of all reported cases, and is more frequent in whites. The actual incidence of malignant melanoma in this syndrome is difficult to determine as many uncomplicated cases go unreported. The most common site of malignant melanoma associated with this entity is in the choroid. Four previously described orbital tumors represent the second most frequent area of presentation. A review of the literature in this disease is discussed as well as a new case of orbital malignant melanoma associated with it. A second case of presumed orbital melanoma associated with oculodermal melanocytosis is also discussed.

Adolescent↗
PubMed1980

Non-specific esterase activity in reactive cells in injured nervous tissue labeled with 3H-thymidine or 125iododeoxyuridine injected before injury.

Tritiated thymidine (3H-TdR) injected before a stab wound of the spinal cord or transection of the hypoglossal nerve has resulted in many labeled reactive cells in the CNS after injury, most of which have the ultrastructural features of microglia. To test for the possible origin of these labeled cells from monocytes, we examined them for the presence of sodium fluoride- (NaF) sensitive non-specific esterase (NSE), an enzyme characteristic of monocytes. Some of the labeled cells in stab wounds had NaF-sensitive NSE, but no such cells were found in the nucleus of the injured hypoglossal nerve. To test for the possibility that the NSE-negative labeled cells had been labeled by reutilization of 3H-TdR, we used 125I-5-iodo-2'-deoxyuridine (125I-UdR), a thymidine analogue with a much lower rate of reutilization, to label blood mononuclear cells prior to either a spinal cord stab wound or hypoglossal axotomy. The number of labeled cells was decreased in the spinal cord wound, but more than half were NSE-negative. No labeled blood mononuclear cells were found in the hypoglossal nucleus, although there was no decrease in the hyperplasia of unlabeled non-neuronal cells. When 125I-UdR was injected on the fourth day after hypoglossal axotomy, or when both 3H-TdR and 125I-UdR were injected simultaneously before hypoglossal axotomy, many labeled cells were found in the hypoglossal nucleus, indicating that 125I-UdR can be used by the reactive cells and that it did not inhibit their proliferation. Therefore, the microglial cells that proliferate in response to peripheral nerve injury are not recently derived from any type of circulating large blood mononuclear cell. The most likely explanation for the presence of the 3H-TdR-labeled cells in the nucleus of the injured hypoglossal nerve is that they were proliferating intrinsic cells labeled by reutilization of 3H-TdR.

Animals↗
PubMedDate not supplied

Accelerated myelination in early Sturge-Weber syndrome demonstrated by MR imaging.

Magnetic resonance imaging of the brain in two infants with Sturge-Weber syndrome has demonstrated a pattern of accelerated myelination in the abnormal cerebral hemisphere. The extent of myelination was most apparent on the T1-weighted inversion recovery sequence while the T2-weighted images demonstrated concomitant changes in hydration of the brain. We propose an explanation for this finding based on cerebral ischemia underlying the leptomeningeal angioma.

Angiomatosis↗
PubMedDate not supplied

Quantitative assessment of ALZ-50 immunoreactivity in Alzheimer's disease.

A quantitative assay for ALZ-50 immunoreactivity was evaluated in samples of superior temporal gyrus taken at autopsy from 13 Alzheimer patients and 11 controls. The assayable immunoreactivity appears to be stable for at least 24 hours postmortem but was lost with formalin fixation. The mean value of the Alzheimer patients was tenfold higher than that of the controls (P less than .002). The values of four Alzheimer samples overlapped with the low levels seen in controls, but no controls had elevated levels. In this sample population, therefore, the assay had a sensitivity of 69% and specificity of 100%.

Aged↗
PubMedDate not supplied

Studies of the endothelial origin of cells in systemic angioendotheliomatosis and other vascular lesions of the brain and meninges using ulex europaeus lectin stains.

Ulex europaeus agglutinin I (UEA-I) is a plant lectin which binds specifically to alpha-L-fucose moieties on the surface glycoproteins of human endothelial cells. The binding is completely inhibited by preincubation of the lectin with fucose. UEA-I can be conjugated directly to fluorescein or peroxidase and can be used to stain endothelium of paraffin embedded tissues. UEA-I staining was evaluated on normal and infarcted brain, systemic angioendotheliomatosis, metastatic epidural angiosarcoma, hemangioendothelioma, hemangioblastoma, angioblastic meningioma of both the hemangioblastic and hemangiopericytic types, and vascular meningioma. The endothelium, but not neuropil of normal and infarcted brain was positive for UEA-I. The tumor cells of hemangioendothelioma and angiosarcoma also stained. However, no staining was seen in malignant intravascular cells of angioendotheliomatosis, the stromal cells of hemangioblastoma, or pericytes of angioblastic meningioma. It is concluded that the malignant cells in angioendotheliomatosis, the stromal cells of hemangioblastoma and the pericytes of angioblastic meningioma do not produce surface glycoproteins characteristic of endothelial cells.

Brain Neoplasms↗
PubMedDate not supplied

Ependymal cyst of the subarachnoid space. Cytologic diagnosis and developmental considerations.

Fluid aspirated from a subarachnoid cystic lesion that covered and compressed part of the left frontal lobe was examined cytologically and compared with histologic sections of the cyst wall. The fluid contained epithelial and histiocytelike cell populations. The epithelial cells were tall columnar, occurring singly or in clusters or sheets. Many cells were ciliated and their cytoplasm showed characteristic refractile granules. The differential diagnosis of this rare type of subarachnoid cyst and the mechanism of the development are discussed. Cytologic evaluation of the fluid of the subarachnoid cysts is potentially a more accurate method of classification of these lesions than is random biopsy of the cyst wall. It is of particular importance in cases with a history of growth, in which the progressive expansion results in attenuation of the diagnostic epithelial lining of the cyst.

Adult↗