Biomedical subjects

V M Elner

Publications and source records attributed to V M Elner.

79 records · Page 5Linked to original sources

PubMed1984

Immunohistochemical localization of apolipoprotein B in human atherosclerotic lesions.

A peroxidase-antiperoxidase immunohistochemical method was used to detect the presence of intracellular and extracellular apolipoprotein B (apo B) in paraffin sections of human abdominal aortas and coronary arteries with and without atherosclerotic involvement. The four aortas studied disclosed both intracellular and extracellular apo B in areas in which lipid was found by oil red O staining. Coronary arteries also demonstrated abundant extracellular apo B but failed to disclose intracellular apo B in cells with stainable lipid. Immunohistochemical detection of intracellular apo B in raised aortic lesions but not in cells of coronary lesions suggests that arteries that contain detectable amounts of intracellular apo B correspond to arteries that usually have earlier atherosclerotic involvement.

Adult↗

PubMed1983

An avidin-biotin-peroxidase method for Fc receptors on macrophages isolated from and in sections of rat lung.

Receptors for the Fc region of immunoglobulin G (Fc receptors) were detected on pulmonary macrophages by adapting an avidin-biotin-peroxidase technique to isolated cells and sections of rat lung. After incubation with soluble rabbit immunoglobulin G (IgG), surface bound IgG was identified consistently and reproducibly on glass-adherent pulmonary macrophages and on macrophages in tissue sections made from incubated lung slices. Control experiments indicated that binding was specifically mediated by surface Fc receptors. This method may be useful for identifying macrophages in intact tissues.

Animals↗

PubMed1983

Identification of macrophages in sections of rabbit lung using acetoacetylated lipoproteins.

Macrophages were labeled in sections of rabbit lung with acetoacetylated low density lipoprotein (LDL), a marker internalized by cultured macrophages but not by other connective tissue cells. Using a modified technique, thin slices of fresh rabbit lung were incubated in 3,3'-dioctadecylindocarbocyanine (DiI)-labeled, acetoacetylated LDL, fixed in paraformaldehyde, and sectioned. Alveolar macrophages incorporated the fluorescently labeled, modified LDL, but surrounding stroma and parenchyma did not stain. Our results indicate that DiI-labeled, acetoacetylated LDL may be used to identify mononuclear phagocytes in tissue sections.

Animals↗

PubMed1981

Immunophagocytic properties of retinal pigment epithelium cells.

Retinal pigment cells were dislodged from normal monkey eyes and incubated in glass-slide chambers. All viable pigment cells adhered strongly to glass. They demonstrated surface receptors for the Fc portion of immunoglobulin G and for the third component of complement by selectively binding and phagocytizing antibody or complement-coated erythrocytes. These phagocytic cells with receptors were identified as retinal pigment cells by characteristic ultrastructural features. Thus, retinal pigment cells, which are generally believed to be derived from neural tissue, are not only scavengers of photoreceptor cell debris, but also have surface receptors and phagocytic functions that may be important in ocular defense.

Animals↗

PubMed1978

Acid lipase: a histochemical and biochemical study using triton X100-naphtyl palmitate micelles.

Hydrolsis of a-naphtyl palmitate dispersed with the detergent Triton X-100 at acid pH was studied by a histochemical diazocoupling technique in both fixed sections and cultures of primate tissues as well as by a biochemical assay employing the same chromogenic substrate. Evidence for the exclusive hydrolysis of this artificial fatty acid ester substrate by acid lipases was gathered from (1) comparison of isoelectric focusing zymograms developed with different substrates, (2) kinetic analysis of enzyme activity in the presence or absence of inhibitors, including a natural substrate of acid lipase, trioleylglycerol, (3) specific localization of marked enzyme activity in certain tissues, and (4) absence of detectable enzyme activity in a case of human acid lipase deficiency (Wolman's disease). Histochemically, acid lipase activity was most readily detected in cells active in the uptake and processing of neutral lipids, i.e., the phagocytes of the reticuloendothelial system, the adrenal cortex and the lipid-storing cells in the athero-sclerotic plaques of arteries.

Animals↗

PubMedDate not supplied

Fat adherence syndrome treated with intraoperative mitomycin-C: a rabbit model.

We used an animal model of restrictive strabismus analogous to the fat adherence syndrome in humans to test the efficacy of topical intraoperative mitomycin-C (MMC) in preventing the development of restrictive scar tissue. A cicatricial adhesion was created between the inferior rectus muscle and the inferior orbital rim of each eye in eight rabbits, and passive forced ductions were quantitatively measured with a spring scale. Eight eyes were treated intraoperatively with topical MMC 0.5 mg/mL, the other eight with sterile water. Passive forced ductions were again measured 4 weeks postoperatively and representative orbits were exenterated for histopathologic examination. Significant restriction of motility was produced in six of the eight control eyes. Though prophylactic treatment with MMC may have been beneficial in some cases, on average, the restriction developing in these eyes did not significantly differ from that in the control eyes. In addition, longer exposure times to MMC led to marked orbital inflammation and severe restriction of ocular motility. Finally, histopathologic evaluation of the orbits of the MMC-treated eyes revealed marked fibrosis of perimuscular connective tissues. Although MMC may have a role in the management of fat adherence syndrome, further study is needed to establish safe and efficacious methods of delivery.

Adipose Tissue↗

PubMedDate not supplied

Photodisruption in the human cornea as a function of laser pulse width.

BACKGROUND: We investigated the role of laser pulse width in determining fluence thresholds and efficiency for corneal photodisruption. METHODS: A laser system that delivers a wide range of pulse energies and pulse widths was used to produce ablations at pulse widths from 100 femtoseconds (fs) to 7 nanoseconds (ns). The laser-induced breakdown fluence threshold at each pulse width was determined by monitoring individual plasma emissions. Using multiple shots, the photodisruption threshold and cutting depth at each pulse width were determined histologically. RESULTS: Corneal breakdown thresholds decreased at a faster rate from 7 ns to approximately 10 picoseconds (ps), compared to further reductions in pulse width below 10 ps, where little variation was seen. Breakdown for pulse widths below 10 ps showed little intershot variability, resulting in highly reproducible fluence thresholds. Corneal tissue examined histologically showed similar fluence dependency. CONCLUSIONS: Corneal tissue photodisruption thresholds demonstrate pulse width dependence. At pulse widths less than 10 ps and with fluences near the breakdown threshold, ablations are maximally precise and efficient. These findings suggest optimal laser parameters for corneal surgery.

Cornea↗