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Biomedical subjects

R W Miller

Publications and source records attributed to R W Miller.

At least 127 records · Page 7Linked to original sources
PubMed1985

Congenital PCB poisoning: a reevaluation.

A review of the literature reveals a need to clarify the pathologic physiology of congenital polychlorinated biphenyl (PCB) poisoning, which is characterized by intrauterine growth retardation, brown staining of the skin and mucous membranes, as in Addison's disease, natal teeth, widely open fontanelles and sagittal suture and apparent overgrowth of the gingiva. The skull abnormalities may represent irregular calcification, with natal teeth appearing because the bone of the mandible is penetrated more easily than usual. Some fetuses were poisoned at the time the mothers ingested the oil; others were affected in the subsequent years from residual contamination in the mothers' bodies. The misadventure in Japan was repeated in Taiwan in 1979. The seven congenital cases in Taiwan reported thus far seem to differ from those in Japan. In Taiwan the noses were somewhat black, two of the infants did not have low birth weight and the osseous abnormalities of the skull and gingival hyperplasia were not observed. Systematic followup studies should be made in Taiwan of the children born within 2 years of maternal poisoning with PCBs. Special attention should be given to age at first dentition and skull X-rays for spotty calcification, among other measures of physical, neurologic and intellectual development.

Calcinosis↗
PubMed1984

Digital subtraction angiography in head and neck radiology.

Intravenous digital subtraction angiography (IVDSA) was used to evaluate 44 patients with suspected otolaryngologic abnormalities. Sixteen had IVDSA for pulsatile tinnitus or suspected glomus tumor of the petrous bone. Nine patients were evaluated because of pulsatile neck masses, and 12 others had suspected tumors of the neck, face, and paranasal sinuses. Seven had IVDSA following head and neck trauma. The technique of examination is described. The current indications of IVDSA in head and neck radiology are discussed. It is concluded that IVDSA is a suitable substitute for conventional angiography for many otolaryngologic conditions and, because of its safety, can be used more liberally.

Adult↗
PubMed1984

Antigen-induced production of lymphokines by human T cell clones specific for hepatitis B surface antigen.

The secretion of gamma-interferon (IFN-gamma), Interleukin-2 (IL-2), and B cell growth factor (BCGF) by human T cell clones specific for hepatitis B surface antigen (HBsAg) was examined. Antigenic stimulation by HBsAg but not by influenza A virus resulted in IFN-gamma and BCGF synthesis by the T cell clones. No detectable amounts of IL-2 were obtained in the supernatants of any of the HBsAg-specific T cell clones when cultured in the presence or absence of antigen. IFN-gamma and BCGF were produced, even when cell proliferation was inhibited, suggesting that the secretion of these T cell factors occurred regardless of cell proliferation. The significance of the various factors in the immune response against hepatitis B virus infection is discussed.

Clone Cells↗
PubMed1984

Membrane Organization of the Desiccation-Tolerant Moss Tortula ruralis in Dehydrated States.

Membrane organization of the desiccation tolerant moss Tortula ruralis was studied in several intensely dehydrated states (75% relative humidity [RH], 90% RH, plasmolysis in molar salt, freezing to -20 degrees C) by (31)P nuclear magnetic resonance and ultrastructural analyses. Both methods revealed that even at 75% RH (-400 bars), the moss cellular membranes retained extended phospholipid bilayers. Ultrastructural analyses of the fully hydrated moss showed an extensive proliferation of membrane vesicles in the endoplasmic reticulum. During dehydration, these vesicles form layers of membrane under the plasmalemma and in some cases appear to fuse with the surface membrane. This suggests that these vesicles may serve as a reservoir of membranes to accommodate for membrane surface area changes during desiccation and subsequent rehydration.

Journal Article↗
PubMed1984

Feeding BAY Vi 7533 to hens.

BAY Vi7533 (2-chloro-N-[[[4-(trifluoromethoxy)phenyl] amino] carbonyl] benzamide) was fed to White Leghorn and Vedette Mini-broiler breeder hens at concentrations ranging from 0 to 25 ppm in the ration. Concentrations of 15 and 25 ppm resulted in greater than 95% mortality of house flies, Musca domestica L., seeded as larvae into the droppings. Concentration of 25 ppm reduced egg production in the White Leghorn but not in the Vedette Mini-broiler hens. At each concentration (except 5 ppm for Vedette Mini-broilers) residues of the compound were detected in the eggs. These residues, however, had no adverse effects on fertility or hatchability of the eggs.

Animals↗
PubMed1984

Susceptibility and immunity to hepatitis B and rubella in a dental school population.

The incidence of hepatitis B infections and the rubella susceptibility of females was assessed in a dental school population, utilizing a commercially available enzyme immunosorbent assay. Surface antibody to hepatitis B virus was found in 8 percent of those individuals who provide direct patient care. The number of subjects nonimmune to rubella virus was 9 percent. Ninety percent of the individuals tested for past hepatitis B infection gave no knowledge of previous illness. More than half of the nonimmune rubella subjects gave a positive history of previous vaccinations or actual measles infection. This study supports the concern that patient histories present some shortcomings when used as monitors of disease history with regard to the rubella and hepatitis B viruses, and demonstrates the value of low-cost, expedient screening in institutions involved in educating health professionals.

Adolescent↗
PubMed1983

Ependymoma, glioblastoma, and acute leukemia in a child.

A 5-year-old boy developed an ependymoma; 3 years later, after chemotherapy and radiotherapy, he developed glioblastoma multiforme and acute myeloblastic leukemia. His maternal grandmother had died at a young age of colon cancer. Since ependymoma is not known to predispose to other cancers, the unusual sequence of malignant disease may have been due to combined therapy in a susceptible host.

Brain Neoplasms↗
PubMed1982

Stimulation of arterial endothelial cell prostacyclin synthesis by high density lipoproteins.

Prostacyclin (PGI2) is a vasoactive prostaglandin synthesized by vascular endothelial and smooth muscle cells. In order to investigate whether plasma lipoproteins influence the biosynthesis and release of prostacyclin by vascular tissues, human high density lipoproteins (HDL) and low density lipoproteins (LDL) were incubated with porcine arterial endothelial cells grown in tissue culture. PGI2 production was measured by radioimmunoassay of its stable metabolite, 6-keto-PGF1 alpha. In incubations of HDL with endothelial cells for 24 h, levels of 6-keto-PGF1 alpha in the medium increased significantly in a dose-dependent fashion to values 5-fold above control. This effect was less pronounced in confluent than in subconfluent cultures and did not occur in the presence of an inhibitor of cyclooxygenase. No significant stimulation of 6-keto-PGF1 alpha was observed when the endothelial cells were incubated with LDL. In time course experiments with HDL, 6-keto-PGF1 alpha levels increased continuously over 24 h. Rat HDL, containing a high content of arachidonate in its cholesterol ester fatty acids, caused a 2-4-fold greater release of 6-keto-PGF1 alpha than human HDL. The delipidated apoprotein of both human and rat HDL caused similar stimulation of 6-keto-PGF1 alpha production, but much less than intact HDL. The data indicate that HDL stimulates PGI2 synthesis by cultured arterial endothelial cells, possibly by providing the cells with arachidonate.

6-Ketoprostaglandin F1 alpha↗
PubMed1982

Effect of platelet-derived and endothelial cell-derived growth factors on the low density lipoprotein receptor pathway in cultured human fibroblasts.

Human platelet-derived growth factor (PDGF) has been previously shown to stimulate low density lipoprotein (LDL) receptor activity in cultured cells. Studies were conducted to delineate in detail the effects of PDGF on the LDL receptor pathway in normal human fibroblasts and to explore relationships between the effects of PDGF on LDL metabolism, on cholesterol metabolism, and on DNA synthesis. Increasing concentrations of PDGF stimulated parallel increases in both DNA synthesis and 125I-LDL cell surface binding. The effect of PDGF was due entirely to an increase (up to 4.3-fold) in the number of receptor sites per cell, and not to a change in receptor affinity (Kd approximately 2.0 nM). Parallel PDGF concentration-dependent increases in 125I-LDL binding, internalization, and degradation at 37 degrees C were observed. The results indicate that PDGF-stimulated cells metabolize receptor-bound LDL in a manner that is identical with that seen with quiescent cells. A single study with highly purified PDGF demonstrated that it was PDGF itself, and not some other component in the partially purified PDGF preparation used in most of this work, that was responsible for the observed effects. Studies were conducted on the effects of PDGF on hydroxymethylglutaryl CoA reductase activity, on cholesterol esterification, and on down-regulation by LDL of the LDL receptor. These studies indicated that LDL cholesterol taken into the PDGF-stimulated cell via the receptor pathway, appeared to become available normally and to have metabolic effects within the cell similar to those seen in quiescent cells. Fibroblasts from subjects with familial hypercholesterolemia showed a normal mitogenic response to PDGF, despite the absence or near absence of an effect on the LDL receptor pathway. Finally, studies were also conducted with endothelial cell-conditioned medium (ECCM), used as a source of the endothelial cell-derived growth factor. ECCM was similar to PDGF in stimulating LDL binding, but differed strikingly from PDGF in that the degradation of internalized LDL was inhibited. As a result, ECCM-treated cells did not effectively increase cholesterol esterification or suppress hydroxymethylglutaryl CoA reductase activity when LDL was present. These findings with substances produced by endothelial cells may have important implications for atherogenesis.

Binding, Competitive↗