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Biomedical subjects

D R Adams

Publications and source records attributed to D R Adams.

At least 37 records · Page 2Linked to original sources
PubMed1991

Distribution of cytochrome P-450 monoxygenase enzymes in the nasal mucosa of hamster and rat.

Deposition of inhaled particulates onto the respiratory mucosa is relatively great in that portion of the nasal cavity unprotected by ciliated, goblet, or keratinized superficial cells. The cytochrome P-450 system is an important enzyme system involved in the biotransformation of xenobiotics into metabolites that are more readily absorbed. To examine the transitional region caudal to the nasal vestibule, nasal tissues of hamster and rat were prepared for immunocytochemistry. Blocks of tissue representing four levels along the long axis of the nasal cavity were examined. Paraffin sections were processed through the avidin-biotin peroxidase procedure, with diaminobenzidine tetrahydrochloride as the chromagen. Enzyme localization was accomplished through the use of antibodies for three rabbit cytochrome P-450 isozymes; 2, 5, and 6 (subfamilies IIB, IVB, and IA, respectively); and for rabbit NADPH-cytochrome P-450 reductase. Enzyme distribution was similar in both hamster and rat nasal tissues except in cells of striated and intercalated ducts of nasal glands and in cells of the nasolacrimal duct where immunoreactivity was greater in the hamster. Immunoreactivity for reductase and isozyme 2 was intense in nonciliated cells lining the nonolfactory epithelium, in sustentacular cells of the olfactory epithelium, and in acinar cells of olfactory glands. Distribution of reaction products to isozyme 5 and 6 were similar to but not so intense as those of reductase and isozyme 2. Reaction products for reductase and isozyme 2 occurred generally in the same cellular and intracellular regions with the following exceptions: isozyme 2 was more concentrated in cells of striated ducts and of the nasolacrimal duct, and reductase was more abundant in intercalated ducts of nasal glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Evaluation of monoclonal antibody-based capture enzyme immunoassays for detection of specific antibodies to measles virus.

Monoclonal antibodies to the hemagglutinin protein, fusion protein, phosphoprotein, matrix protein, and nucleoprotein of measles virus were evaluated as detector antibodies in capture enzyme immunoassays (EIAs) for the detection of specific serum immunoglobulin G (IgG), IgA, and IgM antibodies to measles virus. A pool of monoclonal antibodies to hemagglutinin protein and nucleoprotein proved optimal and was further evaluated. Specific IgM was detected in 97% of adolescents with clinical measles, 97% of infants 3 weeks postvaccination, and less than 1% of normal serum specimens. Specific IgA antibodies were found in 97% of adolescents with clinical measles, 97% of infants 3 weeks postvaccination, and less than 1% of normal serum specimens. Specific IgA antibodies were found in 97% of clinical measles cases and vaccinees, in 26% of healthy persons, and in 36% of infants 8 months postvaccination; consequently, IgA antibodies were not a useful indicator of recent measles infection. A significant increase in IgG antibodies between paired specimens was detected in 92% of clinical cases and all vaccinees. Only 59% of infant specimens had persistent IgG antibodies as detected by capture EIA at 8 months postvaccination, whereas all specimens had antibodies as detected by hemagglutination inhibition and plaque neutralization. An alternative indirect EIA, in which antigen was directly absorbed to the solid phase, was more sensitive than the capture design, detecting IgG antibodies in all infants postvaccination. When standardized with a microneutralization assay for the detection of persistent antibodies, the indirect IgG EIA gave predictive values for positive and negative tests exceeding 90%. Our capture IgM and indirect IgG EIAs provide a practical combination of serologic tests for the determination of acute measles virus infection and past exposure to measles virus or vaccine, respectively.

Antibodies, Monoclonal↗
PubMed1991

[Synthesis of 1-substituted nitroimidazoles and its evaluation as radiosensitizing agents].

The synthesis of various substituted nitroimidazoles with lipophilic and hydrophilic side chains as potential radiosensitizing agents is described. The starting material employed was 4(5)-nitroimidazole, which was alkylated via the sodium salt with various chloro-methylated, substituted alcohols and esters, in order to obtain analogues of misonidazole, metronidazole and desmethylmisonidazole of known radiosensitizing and bactericidal activity. Some final products were assayed for their radiosensitizing properties giving negative results under the testing conditions used.

In Vitro Techniques↗
PubMed1990

Structure and organization of the subepithelial microvasculature in the canine nasal mucosa.

To quantitatively characterize the epithelial microvasculature in the transitional nasal mucosa of the dog, septal, dorsal conchal, and ventral conchal tissues were prepared for light microscopy. Subsequent to the drilling of orientation holes perpendicularly into the epithelium, serial 1.0-micron sections were cut parallel to the epithelial plane. A computerized data acquisition system was used in which the sections were aligned and the lumen/wall interfaces of capillaries digitized. Information stored in the program included the position of capillaries, their diameter, their major axis length, and the angle between their major axis and the X axis of the coordinate system. The intraepithelial capillary loops constituted 9% of the epithelial volume, and had a surface area of 31.18 mm2/mm3 of epithelium, and a length of 1055 mm/mm3 of tissue. Their diameters ranged from 9.1 to 11.3 microns for the three tissues sampled. The distances between afferent and efferent limbs of capillary loops were 4.4, 4.5, and 13.8 microns for nasal septum, alar fold, and dorsal concha, respectively. Additional analyses indicated that capillary loops were neither arranged in rows nor oriented to airflow. Rather than conducting heat to the luminal surface, the primary function of these vessels may be to transport cells and/or cytokines to and from a specialized epithelium, one that is adapted to metabolizing contaminants deposited during breathing.

Analysis of Variance↗
PubMed1990

Synthesis of 1-substitutes-5(6)-nitrobenzimidazoles as potential antiviral compounds.

The synthesis of 1-substituted, acyclic nucleoside derivatives of 5(6)-nitrobenzimidazoles and their pharmacological evaluation as antiviral compounds is described. The compounds were synthesized using 5(6)-benzimidazole as starting material with the appropriate chloromethylated substituted alcohols to obtain analogues of the known antiviral compounds, Acyclovir and Ganciclovir. The antiviral activity of these compounds was evaluated using strains of Herpes Simplex 1 and Poliovirus 1 and were found to be inactive as antiviral compounds under the testing conditions employed.

Antiviral Agents↗
PubMed1990

Epithelium lining the rostral portion of the porcine nasal mucosa.

Epithelial tissues from the rostral half of the pig nasal cavity were prepared for light and electron microscopy. The predominant epithelial cell type at the luminal surface was cuboidal with surface microplicae or microvilli and a multilobate nucleus. Pinocytotic vesicles were a common feature of the adluminal cytoplasmic zone of these superficial cuboidal cells. Other cell types included basal cells, intermediate cells and, occasionally, goblet and ciliated cells. Basal cells contained vesicles located adjacent to the basal lamina. This transitional mucosa may be specialised for sampling substances from the luminal surface preliminary to releasing cytokines and, or, presenting immunogens to intraepithelial lymphocytes.

Animals↗
PubMed1986

Transitional epithelial zone of the bovine nasal mucosa.

To determine the extent and ultrastructure of epithelium lining the transitional nasal mucosa of the neonate, gnotobiotic calf tissues were prepared for scanning and transmission electron microscopy. Stratified cuboid epithelium of the rostral 40% of the nasal cavity contained few ciliated cells; the next caudal 10-15%, although ciliated, had extensive nonciliated areas. The predominant type of surface cell was nonciliated, had short microvilli, and contained a multilobate nucleus and numerous pinocytotic vesicles. In some areas the surface of these cells presented a cobblestone appearance. Basal cells contained numerous bundles of filaments, ribosomes, and basal vesicles. Caudally, nonciliated columnar cells included a cell type similar to the more rostral cuboid cell, as well as brush cells and immature secretory and ciliated cells. Goblet cells were infrequently observed. Intraepithelial nerve terminals were abundant. Other intraepithelial cells, often difficult to identify owing to varying characteristics, included lymphocytes. Based upon comparisons of this neonatal epithelium with mature epithelium, observed in earlier studies of other mammalian species, the transitional mucosa is believed normally to occupy an extensive area of the nasal cavity.

Animals↗
PubMed1986

The bovine vomeronasal organ.

Vomeronasal tissues from four male gnotobiotic calves were prepared for transmission and scanning electron microscopy. Features described include: non-myelinated nerves in the non-neurosensory lamina propria, capillaries in the base of the neurosensory epithelium, sustentacular cells with microvilli 22-26 micron long, neurosensory cells with numerous apical vesicles, cells with cytoplasmic projections containing dense bundles of filaments, and brush cells. The structurally well developed bovine vomeronasal organ is similar in other respects to that reported for a number of other mammals.

Animals↗
PubMed1984

The canine vomeronasal organ.

The vomeronasal organ was studied in mature dogs with the optical, transmission electron, and scanning electron microscopes. The canine vomeronasal complex is structurally well developed. Large blood vessels are present deep to both the lateral, 'non-receptor' and medial, 'receptor' epithelia. In addition to the unmyelinated vomeronasal nerves in the lamina propria deep to the 'receptor' epithelium, numerous nerves containing both myelinated and unmyelinated fibres are present deep to the 'non-receptor' epithelium. The 'non-receptor' epithelium consists of basal cells, ciliated and non-ciliated columnar cells, and globular cells packed with mitochondria. Contained within the 'non-receptor' epithelium are leucocytes, plasma cells, and nerve endings. The 'receptor' epithelium consists of basal, sustentacular, and ciliated receptor cells. The microtubules in cilia of the receptor cells do not appear to have dynein arms or radial spokes.

Animals↗
PubMed1982

Hamster nasal glands: their structure, sialic acid content, and vulnerability to actinomycin D.

This study examines the structure of mucosal glands in the walls of the hamster maxillary recess, compares the histochemical appearance of nasal glands to their sialic acid content, and determines the vulnerability of nasal glands to actinomycin toxicity. Observations were made on plastic-embedded tissue with light and transmission electron microscopes. Determinations of total sialic acid in mucosal samples were conducted with thiobarbituric acid. Experimental hamsters were administered 0.2 micrograms of actinomycin D (IP)/gm body weight/day for five days. Types of granules present in the later nasal gland (LNG) and glands of the maxillary recess (MRGs) include: 2.0 micrometers lightly basophilic, lightly electron-dense granules and 1.5 micrometers strongly basophilic, electron-dense granules in the same acinar cell type in both the LNG and MRGs; 1.5 micrometers metachromatic granules in some acinar cells of the LNG; 1.0 micrometer moderately electron-dense granules in cells of MRG ducts; and 0.7 micrometers electron-dense granules in cells of LNG intercalated ducts. Acid glycoproteins, demonstrable by histochemistry, are present in the LNG but not in the MRGs. However, the total sialic acid content of tissues from MRG tissue is greater than that of other tissues measured. A minor number of LNG acini, those with metachromatic granules, have branching basal cytoplasmic projections. Many dark cells are present in striated ducts of the LNG. Histological alteration due to actinomycin-D toxicity, conspicuous in parotid salivary parenchyma, is greater in MRG than in LNG tissue.

Animals↗
PubMed1981

The lateral nasal gland of dog: its structure and secretory content.

Lateral nasal glands of 12-15 weeks old pups are immature. Gland acini of pups and mature dogs contain numerous electron-lucent vacuoles with basophilic, electron-dense cores. The vacuoles contain both acid and neutral glycoproteins, sialated glycoproteins being the dominant acidic moiety. Lateral and basal cytoplasmic extensions of the acinar cytoplasm greatly increase the cell surface are. Electron-dense granules, smaller and less numerous than the lucent vacuoles of acini, occur in intercalated duct cells. Secretions collected form the excretory duct of the lateral nasal gland from conscious dogs contain 235 mg protein/100 ml secretory fluid. Immunoglobulin A accounts for 14% of the secretory protein. Total sialic acid content is 0.024% of the secretion by weight.

Age Factors↗