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PubMed1971

Isolation and fractionation of the photosynthetic membranous organelles from Rhodopseudomonas spheroides.

Molecular sieve chromatography and sucrose gradient centrifugation were used to prepare large quantities of purified chromatophores from Rhodopseudomonas spheroides. Electron micrographs of these chromatophores revealed that the final preparations were very homogeneous and free of non-chromatophore particulate material. As an additional check on purity, (14)C-l-phenylalanine-labeled aerobic cells, devoid of chromatophores, were mixed with unlabeled photosynthetic cells. The resulting preparation contained less than 1% of the radioactivity, originally located in non-chromatophore protein. The purified chromatophores were solubilized in 2-chloroethanol and separated into two fractions. Fraction P(1) contained 3 to 5% of the total chromatophore protein and could be resolved into 10 electrophoretic components. The second fraction, P(II), contained five electrophoretic components. One of these components had associated with it all of the pigment and phospholipid present in P(II). Preliminary immunochemical studies on these fractions are also reported.

Alcohols↗
PubMed1970

Stalked bacteria: properties of deoxriybonucleic acid bacteriophage phiCbK.

The Caulobacter crescentus bacteriophage phiCbK was studied with respect to the physical and chemical properties of both the phage and its deoxyribonucleic acid (DNA). Electron micrographs reveal the phage to be among the largest DNA bacteriophages reported, with head dimensions of 64 by 195 nm and a flexible tail 275 nm in length. The phage is composed of 57% DNA. This DNA is double-stranded as indicated by (i) the sharp increase in extinction coefficient over a narrow range of temperature increase, (ii) an increase in density in CsCl upon thermal denaturation, and (iii) the equivalence of guanine and cytosine as well as adenine and thymine, determined by chemical analysis. phiCbK DNA cosediments with Escherichia coli phage T2 DNA and has therefore been assigned an S(20,w) value of 63.5S. The size of the phage and its DNA and the percentage of DNA indicate that the phiCbK phage head is relatively loosely packed. The properties of the DNA from bacteriophage phiCbK are similar to those of host C. crescentus DNA with respect to buoyant density, thermal transition point, and guanine plus cytosine content.

Adenine↗
PubMed1992

Alternative staining methods for Lowicryl sections.

A number of stains and stain combinations have been identified that, when used with the hydrophilic resin Lowicryl K11M, produce marked improvements over aqueous uranyl and lead salts (UA-Pb) in terms of low granularity, specificity, and range of components contrasted. Three test specimens, tobacco mosaic virus (TMV), starfish sperm, and cultured mouse fibroblasts, were used to evaluate stain characteristics. UA-Pb showed a preference for nuclei acids, which were stained specifically by osmium ammine-B at pH 1.5. A number of stain combinations in which UA was followed or preceded by salts containing barium, manganese, tungsten, molybdenum, and vanadium provided excellent staining of protein-containing components, each stain combination being unique in terms of the degree to which specific components were discriminated. These stains were particularly effective for visualizing internal components of the nucleus where a number of fibrillar and particulate structures not seen with UA-Pb were well contrasted.

Acrylic Resins↗
PubMed2004

Interrelationships among microbiological, physicochemical, and biochemical properties of Terrincho cheese, with emphasis on biogenic amines.

Changes in the microbiological, physicochemical, and biochemical characteristics of Terrincho cheese as represented by native microflora, pH, water activity, soluble nitrogen fractions, free amino acids, and biogenic amines (e.g., ethylamine, dimethylamine, tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyramine, cystamine, and spermine) during ripening were monitored. Terrincho is a traditional Portuguese cheese manufactured from raw ewe's milk. The main groups of microorganisms (lactococci, lactobacilli, enterococci, pseudomonads, staphylococci, coliforms, yeasts, and molds) were determined following conventional microbiological procedures. Free amino acids and biogenic amines were determined by reverse-phase high-performance liquid chromatography, following extraction from the cheese matrix and derivatization with dabsyl chloride. The total content of free amino acids ranged from 1,730 mg/kg of dry matter at the beginning of the ripening stage to 5,180 mg/kg of dry matter by day 60 of ripening; such an increase was highly correlated with the increase of water-soluble nitrogen in total nitrogen, 12% trichloroacetic acid-soluble nitrogen in total nitrogen, and 5% phosphotungstic acid-soluble nitrogen in total nitrogen throughout ripening. Histamine was consistently present at very low levels, whereas putrescine, cadaverine, and tryptamine were the dominant biogenic amines and increased in concentration during ripening. Ethylamine, tryptamine, phenylethylamine, and cystamine reached maxima by 30 days of ripening and decreased thereafter. Significant correlations between amino acid precursors and corresponding biogenic amines, as well as between biogenic amines and microbial viable numbers, were observed.

Amino Acids↗
PubMed2006

Nasal oncocytoma in a domestic shorthair cat.

An oncocytoma was diagnosed in the nasal cavity of a 12-year-old Domestic Shorthair cat who presented with periocular swelling and sneezing. Histologic examination from biopsy material revealed monomorphic sheets, anastomosing cords, tubules, and acini composed of large polygonal to oval cells that contained abundant finely granular eosinophilic cytoplasm. No vascular or lymphatic invasions were noted. Histochemical stains revealed positive staining of tumor cells with periodic acid-Schiff (PAS) (before and after diastase digestion) and phosphotungstic acid-hematoxylin. Immunohistochemical evaluation of the tumor cells demonstrated positive staining for cytokeratin and negative staining for vimentin, desmin, S-100, glial fibrillar acidic protein, and neuronal specific enolase. Ultrastructurally, the tumor cells contained large numbers of mitochondria within their cytoplasm, which confirmed a diagnosis of oncocytoma.

Adenoma, Oxyphilic↗
PubMed1991

Hyaline globules in Kaposi's sarcoma: a light microscopic and immunohistochemical study.

Hyaline globules (HG) were detected in 51 of 54 Kaposi's sarcoma (KS) lesions (94.4%), including all four non-acquired immunodeficiency syndrome (AIDS) cases of cutaneous KS in this group of cases. Thus, there was no correlation between the presence of HG and the presence or absence of AIDS, nor could we demonstrate any relationship between the presence or prominence of HG and either the histologic pattern or anatomical distribution of KS. HG were located mainly in the cytoplasm of perivascular cells, histiocytoid cells, and spindle-shaped cells and occasionally in endothelial cells lining vessels or slit-like spaces. Extracellular HG were also seen. HG stained positively with periodic acid-Schiff with and without diastase digestion and with phosphotungstic acid-hematoxylin. HG were immunohistochemically negative for alpha 1-antitrypsin, alpha 1-antichymotrypsin, lysozyme, and Factor VIII-related antigen, but the cells containing HG were often positive for alpha 1-antichymotrypsin and occasionally for alpha 1-antitrypsin and Factor VIII-related antigen. HG were also detected in five of six angiosarcomas, two of ten pyogenic granulomas, and seven of 32 inflammatory granulation tissues. These were immunohistochemically similar to HG in KS. Thus, HG are not specific for KS. We support the interpretation that HG are most likely digested erythrocytes.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Intracytoplasmic eosinophilic hyaline globules in cartilaginous neoplasms: a surgical, pathological, ultrastructural, and electron probe x-ray microanalytic study.

Hyaline globules (HGs), spherical intracytoplasmic eosinophilic droplets, have been associated with a variety of conditions, including hepatocellular carcinoma, lung adenocarcinoma, and Kaposi's sarcoma, but they have not been described in cartilaginous tumors. In specimens of 60 cartilaginous neoplasms we found that 22 of 33 chondrosarcomas (67%), eight of 16 enchondromas (50%), and three of seven soft tissue chondromas (43%) exhibited HGs. HGs were seen more commonly in low grade chondrosarcoma (70%) and were relatively rare in high grade chondrosarcoma (25%). No HGs were identified in three osteochondromas, one synovial chondromatosis, or 15 normal cartilaginous tissues taken from various sites. Cartilage associated HGs ranged in size from 2 to 20 microns, were diastase resistant and periodic acid-Schiff (PAS) stain positive, demonstrated autofluorescence, and variably stained with Mallory's phosphotungstic acid-hematoxylin stain (PTAH). A panel of immunostains did not show any specific staining reactions with HGs. Ultrastructurally the HGs were spherical, non-membrane-bound bodies having complex architectural features associated with profiles of rough endoplasmic reticulum. Electron probe x-ray microanalytic (EPXMA) study showed significant peaks of sulphur and calcium. We conclude that HGs represent secretory products of probable glycoprotein nature, may accumulate in a variety of cartilaginous neoplasms, and may be seen more frequently in low grade chondrosarcomas.

Bone Neoplasms↗