PubMed Health⌕ Search

Biomedical subjects

R C Moretz

Publications and source records attributed to R C Moretz.

27 records · Page 2Linked to original sources
PubMed1981

A simple screening procedure for evaluating central nervous system tissue sections showing structural and cytochemical alterations of the blood-brain barrier.

A simple method for rapidly screening and evaluating many areas of central nervous system tissue before and after flat embedding in Beem capsules is described. This method uses light microscopy to select regions surrounding needle track injuries of brain tissue for subsequent fine structural and enzyme cytochemical analysis of the blood-brain barrier. The mouse cerebral cortex was sectioned with a tissue chopper at 40-50 micrometers and reacted with diaminobenzidine to demonstrate the presence of exogenous horseradish peroxidase near an injured central nervous system site. Following the enzyme reaction, both osmicated and unosmicated tissue slices were processed for routine electron microscopy, infiltrated with unpolymerized resin, and evaluated on glass slides by light microscopy prior to flat embedding and polymerization. Numerous tissue specimens can be screened in this way for maximum information per tissue slice, and extra tissue samples can be polymerized on the glass slides and conveniently stored for future sectioning.

Animals↗
PubMed1979

Alzheimer neurofibrillary tangles in diseases other than senile and presenile dementia.

A brief description is given of neurofibrillary changes of the paired helical filament type in a variety of chronic neurological diseases. These include subacute sclerosing panencephalitis, lead encephalopathy, tuberous sclerosis, Down syndrome, Hallervorden-Spatz disease, and lipofuscinosis. In these conditions, with the exception of Hallervorden-Spatz disease neurofibrillary changes were previously recognized but paired helical filaments were identified only in some cases. Moreover, in the present series, the age of patients at death was often younger than in previously recorded cases.

Adolescent↗
PubMed1976

T and B cell patterns in irreversibly rejected human renal allografts. Correlation of morphology with surface markers and cytotoxic capacity of the isolated lymphoid infiltrates.

To define the composition and proliferative and functional activity of the rejection formed sheep erythrocyte rosettes (T cells), expressed surface Ig (B cells) or Fc receptors and specific lymphocyte-mediated cytotoxic activity. Small clumped lymphocytes (48.8 +/- 18.9 per cent) and plasma cells (18.8 +/- 10.9 per cent) were most common and correlated negatively (p less than 0.01). Percentages of surface Ig-bearing and small clumped lymphocytes correlated directly (p less than 0.05) as did the percentages of E rosette-forming and plasma cells (p less than 0.05). The percentages of surface Ig-bearing B cells correlated negatively with E rosette-forming T cells (p less than 0.05). Within this spectrum of rejection, three patterns could be identified. In the first pattern, humoral rejection (by immunofluorescence) was intense and cellular infiltration was primarily by surface Ig and Fc receptor-positive small clumped B lymphocytes. The second and most common pattern consisted of a mixed T and B cell infiltrate with intermediate to high lymphocyte-mediated cytotoxic activity and variable humoral rejection. In the third pattern, invitro studies showed primarily E rosette-forming T cells with paradoxically low lymphocyte-mediated cytotoxic activity. However, morphologic studies also revealed the highest percentages of plasma cells but only mild humoral rejection. Thus, combined morphologic and in vitro studies identified three patterns of protracted renal allograft rejection. Thus, combined morphologic and in vitro studies identified three patterns of protracted renal allograft rejection for which the percentages of plasma cells may provide a distinguishing morphologic marker. Furthermore, the degree of lymphocytic invasion of renal tubules and blood vessels may provide an estimate of lymphocyte-mediated cytotoxic activity.

Antibody Formation↗
PubMed1976

Successful short-term modification of hyperacute renal allograft rejection in the primate. Intrarenal effects of phenoxybenzamine and methylprednisolone combined with heparin.

Inhibition of renal vasoconstriction during hyperacute rejection by phenoxybenzamine or methylprednisolone combined with either the antiplatelet agent pyridinolcarbamate or heparin was evaluted in primates. Phenoxybenzamine plus pyridinolcarbamate did not prolong kidney survival. Phenoxybenzamine plus heparin uniformly prolonged low rates of venous flow to 180 minutes and delayed secondary C3 consumption, sequestration of erythrocytes and platelets, coagulation, and fibrinolysis; neutrophil sequestration and vascular injury and obstruction were more marked than with heparin alone. Host pretreatment with methylprednisolone plus heparin also prolonged the low rates of venous flow to 180 minutes, further reduced secondary alterations, and resulted in the least vascular injury. When intact donor kidneys were also pretreated with methylprednisolone, persistently normal rates of venous flow were achieved. Despite marked consumption of Factor XII, the consumption of C3, other coagulation factors, prekallikrein, and sequestration of formed elements was minimal, and the histology appeared compatible with even more prolonged survival.

Animals↗
PubMed1972

Electron diffraction of wet proteins: catalase.

Electron diffraction patterns having 3500 reflections out to 2 angstromns were obtained from wet microcrystals of catalase. No diffraction was obtained if the water vapor pressure was set below 90 percent of the equilibrium value.

Catalase↗