bluuebunny/crossref_metadata_2025 huggingface dataset:
OXIDATIVE ENZYMES RESPONSIBLE FOR THE CONVERSION OF 3,4-DIHYDROXYPHENYLALANINE TO MELANIN IN THE SMALL INTESTINE OF RODENTS
Authors: MARSDEN C. D.
Published: April 2011

The known capacity of certain cells in the rodent intestine to convert dopa to melanin has been investigated. The cells become pigmented following incubation in dopa solutions at pH 6.8 for 24 hr, but not when incubated in tyrosine. The reaction is prevented by pretreatment with buffer solution at 100°C and ethylene glycol, but not by buffer at 60°C, ethanol or benzene. The reaction is inhibited by sodium azide, ascorbic acid and catalase, but not by protamine sulphate, 4-chlororesorcinol and sodium diethyldithiocarbamate. These results suggest that the enzyme concerned is a peroxidase. The cells concerned are confined to the lamina propria mucosae, and are found in the connective tissue of the spleen and liver. They are also present in peripheral blood. They are eosinophilic and have an affinity for pyronin. They do not contain chromaffin material, nor do they stain with nuclear fast red. It is concluded that they are granular leucocytes, probably eosinophil granulocytes.
CORRELATION OF ACID PHOSPHATASE ACTIVITY WITH DEGREE OF BACTERIAL INFECTION IN HELA CELLS
Authors: JERVIS HELEN ROLAND , LABREC EUGENE H.
Published: April 2011

Acid phosphatase activity has been demonstrated in HeLa cells grown in monolayers on coverslips, using the histochemical method of Barka and Anderson. In normal interphase cells variable enzymatic activity may always be demonstrated in a juxtanuclear position. When the culture medium is inoculated with a virulent strain of Shigella flexneri 2a, a certain number of cells in invaded by the organisms. In the presence of one organism, the acid phosphatase activity of the infected cell appears to increase, but as more organisms are found in individual cells, the intensity of the cells enzymatic reaction decreases. Biochemical assays on whole cell monolayers to quantitate this decrease have failed to show a significant change in enzymatic activity between infected and control cultures, possibly due to the high percentage of cells in any culture that were not infected or infected only slightly.
QUANTITATIVE FLUORESCENCE MICROSCOPY: FLUORESCENT ANTIBODY AUTOMATIC SCANNING TECHNIQUES
Authors: MANSBERG H. P. , KUSNETZ J.
Published: April 2011

The application of microscanning techniques to the detection, classification and counting of fluorescence-tagged microorganisms presents unique and somewhat more severe optical and photometric problems than those encountered in absorption type microscanning. Low fluorescence emission, autofluorescence of optics, filters and specimen mounting media and the close proximity of the excitation and emission wavelengths of typical fluorochromes impose severe limitations on sensitivity and maximum scanning rates. By the use of bright field illumination, liquid dye immersion filters, and careful matching of light source and filter spectral characteristics to those of the fluorochromes, fluorescence output was increased 10-100 times with negligible increase in background level. The effectiveness of a number of light sources filters and phototubes in producing maximal signals from fluorescein isothiocyanate-tagged microorganisms in an experimental fluorescence microscanner are compared. Proper selection produced increases in sensitivity of more than 10 times the initial sensitivity obtained with standard fluorescence microscopes and illuminators. Image plane, object plane and flying spot scanning techniques are compared as to their suitability for fluorescence microscanning. Practical scanner designs are illustrated. A consideration of the advantages of laser excitation of fluorochromes indicates that in addition to greatly simplifying filtering problems, a 102 increase in irradiance can be expected. The possibility of differential diagnosis based upon two color fluorescence discrimination is explored. Overlapping emission spectra presents the major difficulties in such a system. An experimental two color fluorescence microscanner and the optical and electronic techniques employed for the discrimination of overlapping color spectra is described.
HIGH RESOLUTION AUTORADIOGRAPHY WITH DRY MOUNTED, FREEZE-DRIED FROZEN SECTIONS COMPARATIVE STUDY OF SIX METHODS USING TWO DIFFUSIBLE COMPOUNDS H-ESTRADIOL AND H-MESOBILIRUBINOGEN
Authors: STUMPF WALTER E. , ROTH LLOYD J.
Published: April 2011

Localization of two soluble compounds, 3H-estradiol in liver and uterus and 3H-mesobilirubinogen in liver, has been studied by six autoradiographic methods: (I) Frozen sections, freeze-dried, dry mounted on emulsion-coated slides; (II) Frozen sections thawed on emulsion-coated slides; (III) Frozen sections thawed on glass slides and dipped in liquid emulsion; (IV) Freeze-dried tissue, vapor-fixed, epoxy-embedded, sectioned, dipped in liquid emulsion; (V) Freeze-dried tissue, paraffin-embedded, sectioned, deparaffinized, dipped in liquid emulsion; and (VI) Formalin-fixed tissue, paraffin-embedded, sectioned, deparaffinized and dipped in liquid emulsion. Methods II-VI show varying degrees of diffusion, and in some cases loss of activity from tissue, when compared with results obtained by dry mounting of freeze-dried frozen sections. Autoradiograms prepared by dry mounting of 0.75-, and 1-µ thick sections, cut and dried below –60°C, have been found superior.
ENZYMES IN HOG KIDNEY HYDROLYZING AMINO ACID NAPHTHYLAMIDES
Authors: VANHA-PERTTULA T. , HOPSU V. K. , GLENNER G. G.
Published: April 2011

Hydrolysis of β-naphthylamides of a number of amino acids and dipeptides and of a number of di- and tripeptides by hog kidney homogenate and by fractions obtained by various fractionation procedures has been studied. The substrates were found to be split by a soluble, apparently sulfhydryl-dependent enzyme, and by a particle-bound, metal-activated enzyme. The former constituted only a small part of the total activity. The latter was subfractionated by starch gel electrophoresis into two fractions with identical characteristics. The soluble and particle-bound enzymes differed also in their substrate specificity. The latter enzyme was solubilized, partially purified, characterized by some modifier compounds and compared with enzyme preparations obtained by various fractionation procedures presented by other investigators. Thus enzyme showed ion-determined substrate specificity, i.e., hydrolysis of some of the amino acid naphthylamides was found to be activated by Co++ while the hydrolysis of others was inhibited by the same metal ion.
A DIAZOSULFANILIC ACID AZURE A SEQUENCE FOR TISSUE PROTEIN
Authors: LILLIE R. D. , PALMER R. W. , GUTIÉRREZ A.
Published: April 2011

When azo coupling of tissue with freshly diazotized sulfanilic acid at 20-25 mM concentration in a bicarbonate solution is followed by acid washing and staining with dilute azure A or safranium O solutions at pH 1, the azo coupling sites in tissue are demonstrated with green to greenish black or red colors of sufficient intensity to render the method useful for the study of the distribution of reactive proteins. Erythrocytes react more strongly by this method than with most other diazonium salts. The method also affords a procedure for creating readily demonstrable sulfonic acid groups in tissue sections, for the study of their reactions in comparison with those of ester sulfuric acid groups.
SUBCELLULAR LOCALIZATION OF RAT BRAIN ESTERASES
Authors: BERNSOHN JOSEPH , BARRON KEVIN D. , DOOLIN PAUL F. , HESS ADELINE R. , HEDRICK MARJORIE T.
Published: April 2011

The localization and properties of soluble and bound esterases of subcellular fractions of rat brain have been investigated. Bound esterases were extracted with 1% Triton X-100 and separated by starch gel electrophoresis. By these means a molecular population of isoenzymes was demonstrable that was quantitatively different from the isoenzyme population of the watersoluble esterase activity. The highest specific activity for α-naphthyl acetate hydrolysis was contained in the microsomal fraction and could be extracted by Triton. In contradistinction to whole brain and to other subcellular fractions, microsomes contained a molecular population of esterase isozymes which was qualitatively distinct from that of water extracts in that the fast moving A-type esterases were absent. In addition, there was present a heavy concentration of slow movinig B-esterase. Acetylcholinesterase could also be extracted from this fraction by Triton, migrated with B-esterase and actively hydrolyzed αnaphthyl acetate. Combined electron microscopic and quantitative chemical analysis of the subcellular fractions suggested that some bound nonspecific esterase may be localized in sub-synaptic membranes.

The pI50 values for E 600 of the soluble and insoluble, Triton X-100-extracted and Triton X-100-insoluble esterases are, respectively, 5.3, 7.5, 7.5 and 7.4. It is noted that these results may be determined in part by the participation of acetylcholinesterase in hydrolysis of the substrate. Mitochondria are virtually devoid of esteratic activity. C-type esterase (CMB-activated, E 600-resistant) occurred in both the bound and soluble state. A-, B- and C-type esterases exist in both bound and soluble forms and their chemical properties appear to be independent of their site of localization. Histochemical studies indicate that the B-type esterase is localized predominantly to cytoplasm of neurons and to neuropil. A-esterase is localized to droplets (presumed lysosomes) of neurons and other cell types, e.g., pericytes. The histochemical localization of C-esterase could not be determined.
DETECTION OF HISTAMINE BY A NEW FLUORESCENT o-PHTHALALDEHYDE STAIN
Authors: JUHLIN LENNART , SHELLEY WALTER B.
Published: April 2011

A simple, rapid technique has been developed for the visualization of histamine in its cellular depots throughout the body. Based on the yellow fluorochrome formed by the interaction of o-phthalaldehyde and histamine, this procedure permits direct fluorescence microscopy of the "histaminocytes." Study of fresh blood and tissues from man and many animals revealed histamine its the mast cells, blood vessels, gastric mucosa, and in some species, platelets.
GLYCOGEN SYNTHETASE AND PHOSPHORYLASE IN RED AND WHITE MUSCLE OF RAT AND RHESUS MONKEY
Authors: BOCEK ROSE MARY , BEATTY CLARISSA H.
Published: April 2011

Homogenates of red and white muscles from rats and monkeys were assayed for total phosphorylase and phosphorylase a and for the total and independent forms of glycogen synthetase. Total and phosphorylase a activities were higher in the supernatant fraction of homogenates of white as compared with red muscle from both rats and monkeys. Both forms of phosphorylase were higher in white muscle from rats when assayed on whole homogenates. The total and d form of glycogen synthetase activities were higher in red muscle from both species of animals. The ratio of I/total synthetase was 2- to 3-fold higher in muscle from monkeys as compared with that from rats. These results support histochemical evidence that phosphorylase is higher in white muscle fibers and glycogen synthetase is higher in red muscle fibers.
USE OF THE DIRECT-COLORING THIOCHOLINE TECHNIQUE FOR DEMONSTRATION OF INTRACELLULAR NEURONAL CHOLINESTERASES
Authors: BELL CHRISTOPHER
Published: April 2011

A study has been made of factors influencing the effectiveness of the "direct-coloring" thiocholine technique in demonstrating intracellular cholinesterases in motor neurons. It has been found that certain procedures likely to produce disruption of the neuronal membrane are necessary for efficient penetration of the ferricyanide component of the staining medium. The procedures used were osmotic shock and brief freezing of the tissue. The results are discussed with regard to application of the direct-coloring technique to electron-microscopy.
THE DEMONSTRATION OF ACID HYDROLASE, THERMOSTABLE REDUCED DIPHOSPHOPYRIDINE NUCLEOTIDE TETRAZOLIUM REDUCTASE AND PEROXIDASE ACTIVITIES IN HUMAN LIPOFUSCIN PIGMENT GRANULES
Authors: GOLDFISCHER SIDNEY , VILLAVERDE HUMBERTO , FORSCHIRM REGINA
Published: April 2011

The characterization of human lipofuscin pigment granules as lysosomes is strengthened by the cytochemical demonstration of β-glucuronidase and glucosaminidase activities in hepatocyte pigment granules which also have acid phosphatase activity. Lysosomes of parenchymal cells and macrophages are seen to differ in their content of cytochemically demonstrable hydrolase activities. Reduced diphosphopyridine nucleotide tetrazolium reductase and peroxidase activities that are remarkably resistant to heat (90°C for 15 min) and prolonged fixation are also visualized in lipofuscin granules. It is suggested that these oxidative activities reflect the presence of heme compounds that accumulate during the degradation of cytoplasmic constituents in autophagic vacuoles or dense bodies. The presence of metabolites with peroxidase activity within lysosomes may be responsible for the oxidation of melanin precursors to melanin and unsaturated fat to the alcohol-insoluble lipid of lipofuscin pigment. Cytoplasmic iron (hemosiderin) that is stained by Perls' ferrocyanide or Quinke's sulfide procedures is also visualized by incubating sections for peroxidase activity in Karnovsky's 3,3'-diaminobenzidine medium. This activity disappears following the extraction of stainable iron in Lillie's dithionite medium. However, the heme-associated peroxidase activity is unaffected.
A HISTOCHEMICAL AND BIOCHEMICAL STUDY OF NUCLEAR ADENOSINE TRIPHOSPHATE HYDROLYSIS IN EMBRYO HEART
Authors: KLEIN RICHARD L.
Published: April 2011

A correlative histochemical study using cryostat sections and a biochemical study using isolated nuclei were undertaken to characterize nuclear adenosine triphosphate (ATP) hydrolysis in embryonic myocardium of the chick. Qualitatively, the data give an unequivocal positive correlation between the two studies except for minor sensitivity differences. A variety of criteria establish the enzymatic nature of the nuclear ATP hydrolysis and affirm the presence of at least one ATP phosphohydrolase. Enzyme activity is probably localized both at the nuclear surface and in the nucleoplasm. Mg++-activated ATP phosphohydrolase is predominant over the Ca++-activated enzyme, and the former is stimulated by the addition of NaCl. The characteristics of the enzyme activity and the combined methods employed eliminate the possibility that the observed activity is due to artifact or to contamination by other cell fractions.
Mobile communication in the global south
Authors: Ling Rich , Horst Heather A.
Published: April 2011

Mobile communication has become a common phenomenon in most parts of the world. There are indeed more mobile subscriptions than there are people who use the internet. For many people outside of the metropolitan areas of Europe and North America, this is literally their first use of electronically mediated interaction. This preface to the special issue of New Media & Society examines mobile communication in a global context. Through an overview of eight articles situated in the global south, we describe how mobile communication sheds light upon notions of information, appropriation and development and how it is challenging, and in many cases changing, notions of gender. While the mobile phone reshapes development and micro dynamics of gendered interactions, it is not necessarily a revolutionary tool. Existing power structures may be rearranged, but they are nonetheless quite stable. The analysis of mobile communication in the global south helps us to understand the rise of innovative practices around information and communication technologies and, in turn, enables us to develop theory to understand these emergent empirical realities.
‘We use it different, different’: Making sense of trends in mobile phone use in Ghana
Authors: Sey Araba
Published: April 2011

Drawing on ideas from the sustainable livelihoods approach to poverty reduction and the concept of technology appropriation, this article discusses findings from a mixed methods study exploring mobile phone use in Ghana. The results suggest that most respondents value their phone for the connectivity it affords with a variety of personal and professional contacts. In this sense, the mobile phone is not an overt means of poverty reduction for respondents but an integral part of their lives, in which it serves multiple functions. The study contributes empirical data to the emerging body of research on mobile phone communication in African countries.
User production reconsidered: From convergence, to autonomia and cultural materialism
Authors: Hamilton James F. , Heflin Kristen
Published: April 2011

This article addresses the phenomenon of user production. Upon addressing critically the concept of convergence, it suggests autonomia as an alternative perspective that is exceptionally sensitive to the novelty of digital-media work. However, its value remains limited due not only to a residual technological determinism, but also due to lacking a means of concrete, historical analysis of practice. We propose melding the insights of autonomia with a sustained analysis of practice through the cultural materialism of Raymond Williams. The article concludes with an analysis of user involvement at the cable-television and internet commercial company Current TV, which demonstrates the value of this melded perspective for making sense of user production.
An evaluation of students’ perceptions and engagement with e-learning components in a campus based university
Authors: Ituma Afam
Published: April 2011

This article explores the pattern of use of a typical e-learning system by students in a campus based university. Whilst numerous studies of e-learning have provided fascinating insights into its potential benefits, a common concern is that mainstream studies in this area have focused largely on staff experience with limited attention paid to students’ perceptions and engagement. This study goes some way in bridging this gap by exploring students’ perceptions and patterns of use of a typical e-learning system. The findings suggest that a large percentage of the students had very positive perceptions and the frequency of usage of the e-learning system was also very high, with the vast majority using it frequently to supplement the traditional face-to-face classroom method. These results were irrespective of gender, age and nationality. Some of the implications of the findings are discussed.
Preserving the ‘‘us identity’’ through marriage commitment while living with early-stage dementia
Authors: Davies Judie C.
Published: April 2011

Recognizing the impact of marriage commitment to living with early-stage dementia has important implications for developing proactive care for individuals with dementia and their families. This mixed method study of six couples experiencing early-stage Alzheimer’s dementia explored how married couples experienced the meaning of commitment through memory loss represented by the transitional process of pre-diagnosis, diagnosis, and post-diagnosis. Narrative analysis was used to identify shared themes from couples’ accounts through semi-structured interviews and supported by questionnaires related to commitment and marriage satisfaction. Couples’ commitment was expressed by four major themes: ‘partnership for life’, ‘reciprocity’, ‘resilience’, and ‘forgiveness’. Couples’ experienced an undisturbed, enduring commitment to their relationship in spite of the diagnosis of dementia. The ‘us identity’ of the couple, living-in-relationship, remained intact. Couples considered the challenge of dementia to be a collaborative venture — a journey into the unknown.
DELAYED AND DIRECT LABELING AFTER A SYSTEMIC INJECTION OF THYMIDINE-3H
Authors: GALASSI LEONE
Published: April 2011

The variation in the radioautographic pattern of labeling was studied in uteri during decidual proliferation for some days after a systemic and after a local injection of thymidine-3H. In the systemically injected animals the decidual cells showed a delayed uptake of thymidine-3H from the circulation, which was responsible for up to 100% labeling of these cells, 48 hr after injection, against the 20% labeling of locally injected uteri, after an identical length of time. An analysis of the grain count distributions revealed that 10% of cells with high grain density was present in both preparations. It thus appeared that all the "high" cells derived their label by direct uptake. Because of the difference in concentration and duration of availability of tritiated thymidine, immediately after injection and during delayed release, criteria could also be established to differentiate, on the basis of different grain patterns, between directly and indirectly labeled nuclei among the population of "low" cells.
NONSPECIFIC ESTERASES IN RAT PROSTATIC EPITHELIAL CELLS
Authors: FROST JAMES L. , BRANDES DAVID
Published: April 2011

Prostates from normal and recently castrated rats were examined for the localization of esterase activity using Holt's indoxyl acetate method. Tissue fixed in formalin mixtures containing sucrose showed preservation of abundant cytoplasmic esterase activity while tissue fixed in formalin mixtures lacking sucrose had little cytoplasmic esterase activity. Esterase activity in droplets was abundant after both fixations. The difference could not be explained by ferroferricyanide inhibition, pH or osmolality of the fixative, and is attributed to a protective effect of sucrose during fixation. E600 greatly reduced cytoplasmic esterase activity in normal and castrated rats. Esterase activity in droplets was resistant to E600 in both normals and castrates. Ribonuclease extraction reduced cytoplasmic esterase activity in both normal and castrated rats only slightly, indicating no association of cytoplasmic esterases with ribosomal ribonucleic acid. Cytoplasmic esterase activity is reduced in castrates in which the epithelial cells of the prostate also show a decrease in endoplasmic reticulum and ribosomes. Similarity of location of droplet esterase activity and of lysosomes marked by acid phosphatase and reduction in droplet esterase activity by saline extraction are cited as evidence for a lysosomal localization of E600-resistant esterase.
CERTAIN DEHYDROGENASE ACTIVITIES AND DRY WEIGHT OF NORMAL AND MALIGNANT MAST CELLS
Authors: DIAMANT BERTIL , GLICK DAVID
Published: April 2011

Total dry weight of individual lyophilized peritoneal malignant mouse mast cells (line P-815, Dunn-Potter) was found to have a mean value of 219 ±7 pg compared with 2.4 times this for normal rat peritoneal mast cells. Lactic, glucose 6-phosphate, 6-phosphogluconate and isocitric dehydrogenase activities in suspensions of whole and of disrupted malignant cells were measured fluorometrically. The lactic dehydrogenase activity per unit weight of protein of the malignant cells was found to be about 19 times that of the normal cells, and the other enzymes, which do not appear to be present in the normal cells, were demonstrated in the malignant cells. Freeze-thawing, temperature and time of storage and presence of protein influenced the individual enzyme activities differently. Protein was generally protective against inactivation, and that due to freeze-thawing, which was used to disrupt cells for enzyme liberation, was minimized in the presence of serum or plasma albumin. Protein did not, however, protect against enzyme inactivation because of prolonged storage of the cells in the frozen state.
THE FINE STRUCTURE OF CEROID IN HUMAN ATHEROMA
Authors: GYÖRKEY FERENC , SHIMAMURA TETSUO , O'NEAL ROBERT M.
Published: April 2011

Ceroid in human atherosclerotic aorta was identified with histochemical tests (acid-fast, oil red O and periodic acid-Schiff techniques) applied to Epon-Araldite- and methacrylate-embedded tissues from which immediately adjacent ultrathin sections were studied with the electron microscope. The fine structure of ceroid in the human atherosclerotic aorta appears to be heterogeneous, showing uniquely wavy, irregularly arranged lamellae lying within granular material of varying electron density. The lamellar structure shows regular and alternating parallel electron-dense and electron-lucent zones which we believe to be characteristic of ceroid.
METAL SALTS-HEMATOXYLIN STAINING OF SKIN KERATOHYALIN GRANULES
Authors: PIZZOLATO PHILIP , LILLIE R. D.
Published: April 2011

The stratum granulosum of the mammalian skin contains keratohyalin granules which have been shown to have an affinity for salts of aluminum, chromium, copper and iron. To determine whether these granules have an affinity for other elements and whether the granule-metal complexes can be stained, salts of 64 metals were tested. Histologic sections of animal and human skin were treated with 0.01 M solution of various metal salts for 4 hr, washed in distilled water and stained with 1:10,000 dilution of unoxidized hematoxylin in 0.01 M phosphate butffer, pH 7.0, for 4 hr. In the cationic state, Al, Cr, Ga, Hf, In, Fe and Zr formed dark blue granules. Be, Dy, Ho, Ir, Pb, Mn, Mo, Nd, Ni, Pt, Rh, Tb, U, Yb and Zn produced lighter blue granules. The granules produced by Bi were purple; Ta, brown-red; Nb and Ti, brown; Cu, greenish blue; Sn and Th, purplish red; Os, blue- or green-brown. The metals were not extracted by washing in water up to 72 hr. Some metals were extracted by 1 N HCl and by 10% Versene.
THE FORMALDEHYDE FLUORESCENCE METHOD FOR THE HISTOCHEMICAL DEMONSTRATION OF BIOGENIC MONOAMINES A REVIEW ON THE METHODOLOGY
Authors: CORRODI HANS , JONSSON GÖSTA
Published: April 2011

The histochemical fluorescence method of Falck and Hillarp for the demonstration of biogenic monoamines is based on the finding that the amines can be condensed with formaldehyde to yield strongly fluorescent compounds, provided that they are enclosed in a dried protein layer, as in freeze-dried or air-dried tissues. This review deals mainly with certain principal features of the method: its chemistry, sensitivity, specificity and possibilities for histochemical differentiation between the various amines. Some comments are made on certain of the results obtained with this method.
DIFFERENTIATION OF RED AND WHITE FIBERS IN MUSCLE FROM FETAL, NEONATAL AND INFANT RHESUS MONKEYS
Authors: BEATTY CLARISSA H. , BASINGER GLAYDIS M. , BOCEK ROSE MARY
Published: April 2011

The hydroxyproline (collagen) content of muscle in terms of wet weight was lowest at 90 days gestational age (rhesus monkey) and increased until birth. Histologic techniques also demonstrated a progressive increase in staining density for connective tissue with increasing fetal age. However, when expressed in terms of nitrogen content of muscle, the hydroxyproline concentrations were similar from the 90-day fetal through the 2-6-week infant series, and were consistently higher in rapidly growing as compared to adult muscle. The succinic dehydrogenase activity (soleus), on the basis of wet weight or of nitrogen, was lowest in the 90-day fetal series and reached a plateau by 120 days. The histochemical data indicated an increase in staining density for succinic dehydrogenase in muscle as the fetus matured. By 90 days gestational age, the hydroxyproline concentration of red muscle was lower as compared to that of white muscle, and this difference was also apparent histologically. The succinic dehydrogenase activity was higher in red as compared to white muscle at all ages, and histochemical differentiation was apparent at 120 days fetal age.
DETERMINATION OF 3β-HYDROXYSTEROID DEHYDROGENASE SYSTEM IN MICROGRAM SAMPLES OF TISSUE, QUANTITATIVE HISTOLOGIC DISTRIBUTION OF THE ENZYME IN THE RAT ADRENAL AND EFFECTS OF ADRENOCORTICOTROPIN
Authors: SCHOR NORBERTO A. , GLICK DAVID
Published: April 2011

A fluorometric method for determination of the 3β-hydroxysteroid dehydrogenase system in microgram samples of tissue, based on nicotinamide adenine dinucleotide reduction by pregnenolone, was developed and applied to the quantitative histologic distribution of the enzyme in the adrenal gland of the rat. Single subcutaneous injections of adrenocorticotropin in saline solution (25 mg/kg) and daily injections for 6 days of the same dose in gel resulted in no demonstrable influence on either the activity or distribution of the enzyme. The distribution observed was relatively uniform throughout the cortex, although a tendency to greater activity in the glomerulosa was found in some cases, and no appreciable activity was seen in the medulla. The data supported those in the literature, indicating that this enzyme is not rate limiting in the biosynthesis of corticosterone in the adrenal following stimulation by adrenocorticotropin.
IN VITRO EFFECTS OF FLUORIDE ON TRICARBOXYLIC ACID CYCLE DEHYDROGENASES AND OXIDATIVE PHOSPHORYLATION: PART I
Authors: LOVELACE C. JAMES , MILLER GENE W.
Published: April 2011

Studies were conducted on the in vitro effect of fluoride on the succinic oxidase system utilizing mitochondria obtained from cauliflower. Preincubation of mitochondria with fluoride did not increase inhibition of succinic oxidase. Various other tricarboxylic acid cycle substrates were used to determine their sensitivity to fluoride; only succinate oxidation was affected. A series of succinate concentrations in the presence and in the absence of fluoride showed increased activity of succinic dehydrogenase, which indicated competitive inhibition. Various concentrations of phosphate in the absence of fluoride showed that phosphate had only slight effects on the succinic 2,6-dichlorophenolindophenol reductase component of the succinic oxidase system. In the absence of phosphate, various concentrations of fluoride showed an initial increase in activity followed by a decrease in activity of succinic 2,6-dichlorophenolindophenol reductase. In the presence of phosphate, fluoride caused marked inhibition of succinic 2,6-dichlorophenolindophenol reductase. It is believed that this inhibition results from an enzyme-fluorophosphate complex which has a lower dissociation constant than that of the enzyme-substrate complex. An oxidative phosphorylation study indicated that both respiration and phosphorylation were inhibited.
THE USE OF PHENAZINE METHOSULFATE FOR IMPROVING THE HISTOCHEMICAL LOCALIZATION OF KETOSE REDUCTASE (l-IDITOL: NAD OXIDOREDUCTASE, OR SORBITOL DEHYDROGENASE)
Authors: JOHNSON ANNE B.
Published: April 2011

An improved histochemical localization of the activity of ketose reductase, a nicotinamide adenine dinucleotide-dependent enzyme, was achieved by using an incubating medium containing phenazine methosulfate. Fixed sections of mouse male accessory reproductive glands, liver and kidney reacted faster in the presence of phenazine methosulfate, yet without the false localizations found with media lacking this compound. At the cytologic level, phenazine methosulfate caused a fine deposition of formazan in the cytoplasm of all reactive tissues, whereas without it granules presumed to represent mitochondria were stained. Phenazine methosulfate is believed to produce these effects by serving as an intermediate electron acceptor between reduced coenzyme and tetrazolium. Thus detectable diffusion of reduced coenzyme did not occur because phenazine methosulfate improved trapping. The concentrations of both phenazine methosulfate and coenzyme were critical in obtaining accurate cytologic localization. The use of cyanide with phenazine methosulfate, although necessary with unfixed tissues, was not essential with fixed tissues.
CYTOCHEMICAL DEMONSTRATION OF GLUTATHIONE REDUCTASE (EC 1.6.4.2) IN SACCHAROMYCES CEREVISIAE
Authors: REISS JÜRGEN
Published: April 2011

A method for the cytochemical demonstration of glutathione reductase in unfixed yeast cells ( Saccharomyces cerevisiae) is described using reduced glutathione as substrate, nicotinamide adenine dinucleotide phosphate (nicotinamide adenine dinucleotide) as coenzyme and nitro blue tetrazolium as indicator. An essential prerequisite is an exactly controlled pH level (pH 6.5) of the complete incubation medium.
MOTOR END PLATE REACTIVITY TO DIVALENT METAL IONS HISTOCHEMICAL STUDIES
Authors: NAKAMURA TOSHIO , NAMBA TATSUJI , GROB DAVID
Published: April 2011

Motor end plates in the tibialis anterior muscle of the rat were demonstrated by metal sulfide deposits following injection of aqueous solutions of lead, stannous, cadmium, zinc or cupric ions into the muscle in vivo or in vitro. The appearance of the end plates was similar to the structure demonstrated by cholinesterase staining, with visualization of the subneural apparatus. Neither metal binding nor cholinesterase activity was affected 4 weeks after dissection of the sciatic nerve, indicating that the metal binding site is postsynaptic. Freezing or formalin fixation of muscle prevented binding of all metal ions to the end plate without greatly affecting cholinesterase activity, indicating that these two activities of the end plate are distinct. Prior administration of acetylcholine, d-tubocurarine, neostigmine or diisopropyl fluorophosphate inhibited binding to the end plate of cadmium and zinc ions but did not alter binding of lead and stannous ions. By formation of a lake with alizarin red S previously injected in vivo intramuscularly, the release of calcium ions at the motor end plate following stimulation of the muscle through the nerve or administration of neostigmine was demonstrated. These results suggest a close relationship of the site of binding of divalent metal ions in the motor end plate to the site of calcium release, and a close but not identical relationship to the site of cholinesterase activity and the acetylcholine receptor.
p-HYDROQUINONE AND p-BENZOQUINONE AS HISTOCHEMICAL REAGENTS I. A NEW TETRAZOLIUM METHOD FOR AMINO GROUPS, AND THE MECHANISM OF FORMAZAN STAINING OF PARAFFIN AND FRESH FROZEN SECTIONS
Authors: CARMICHAEL G. G. , MANDER STEPHANIE T. K.
Published: April 2011

The staining of amino groups by formazan when dehydrated paraffin sections are incubated in a mixture of hydroquinone and 3-(4,5-dimethyl thiazolyl-2)-2 ,5-diphenyl-2H-tetrazolium bromide at an acid pH is reported. The mechanism of this reaction and of the cytoplasmic deposition of formazan in fresh frozen sections incubated under similar conditions is investigated. It is shown that the oxidation of hydroquinone to semiquinone is responsible for the reaction, the tetrazole acting as electron acceptor. The tissue amino groups, exposed by dehydration and thermal shrinkage, and the nitrogen groupings of phosphobipid behave as "catalysts." The relevant properties of the hydroquinone-benzoquinone oxidation-reduction system are described, and the reactions between benzoquinone and tissue constituents are reviewed.
LOCALIZATION OF MYOGLOBIN IN HUMAN SKELETAL MUSCLE USING FLUORESCENT ANTIBODY TECHNIQUE
Authors: KAGEN LAWRENCE J. , GUREVICH RAYA
Published: April 2011

Rabbit antiserum to human myoglobin was used with the indirect fluorescent antibody technique to localize this protein in human skeletal muscle. Specific fluorescence was noted, in rapidly frozen and acetone-fixed sections, to be located at the transverse striations, at the sarcolemmal regions and at certain fibrillar structures within the cell. The antibody fluorescence reaction was shown to be specific for myoglobin, and was not produced by normal rabbit serum of serum of rabbits immunized with bacterial antigens. The reaction was abolished by prior absorption of the antimyoglobin serum with myoglobin, and was found to be absent in tissues deficient in myoglobin (lung, kidney, spleen, liver and uterus). Omission of acetone fixation or delayed freezing resulted in leakage of myoglobin from the cell and loss of specific intracellular localization. Sarcolemmal localization appeared to be somewhat more stable.
ON THE LOCALIZATION OF SOME PHOSPHATASES IN THREE DIFFERENT SEGMENTS OF THE PROXIMAL TUBULES IN THE RAT KIDNEY
Authors: JACOBSEN N. O. , JØRGENSEN F. , THOMSEN Å. C.
Published: April 2011

The distribution of several phosphatases in three segments of the proximal tubules was studied in frozen sections of glutaraldehyde-fixed rat kidneys. Two segments of the convoluted tubules were identified by in vivo injection of trypan blue. By increasing the concentration of adenosine triphosphate to 3 mM in the Wachstein and Meisel ATPase medium, a clear segmental differentiation in the reaction pattern of the brush border, cytoplasmic bodies and basal infoldings of the proximal tubules was obtained. The specificity of the reaction was investigated by substituting adenosine diphosphate, adenosine monophosphate or β-glycerophosphate for adenosine triphosphate in the incubation medium and by employing cyanide or fluoride as inhibitors. The reaction pattern was also compared with the localization of acid and alkaline phosphatase activities. In addition, the distribution of glucose 6-phosphatase activity was studied which showed differences in the three segments of the proximal tubules.
THE HISTOCHEMICAL DEMONSTRATION OF INTESTINAL β-d-FUCOSIDASE WITH 5-BROMO-4-CHLOROINDOLE-3-yl-β-d-FUCOPYRANOSIDE
Authors: ESTERLY JOHN R. , STANDEN ALFRED C. , PEARSON BJARNE
Published: April 2011

Enzymatic hydrolysis of a halogen-substituted indolyl substrate for β-d-fucosidase shows a strong positive reaction in the interstitial mononuclear cells in the jejunum. This localization and the optimum pH are different from that of the analogous substrate for 3-d-galactosidase. The results of competitive inhibition of these substrates suggest that the reactions demonstrate distinct but similar tissue enzymes.
THE INFLUENCE OF DEVELOPMENT ON THE NUMBER AND APPEARANCE OF SILVER GRAINS IN ELECTRON MICROSCOPIC RADIOAUTOGRAPHY
Authors: KOPRIWA BEATRIX MARKUS
Published: April 2011

Under conditions similar to those in electron microscopic radioautography, the development of three different nuclear track emulsions—Ilford L4, Gevaert 307 and Kodak NTE—was investigated by varying the type of developer, duration of action and temperature. These three factors influence: (1) the number of silver grains produced from exposed silver bromide crystals and, therefore, the sensitivity of the emulsion; (2) the production of a few silver grains from silver bromide crystals, unexposed to radiation from the specimen, that is, the background fog; and (3) the size and shape of the developed silver grains, thus influencing the resolving power. The developed silver grains increase in number and in size with increasing duration of development. After complete development in most developers, the silver grains consist of highly convoluted silver filaments and are 2 or 3 times as large as the original silver bromide crystals. However, small grains may be obtained by brief development in Loveland's and p-phenylenediamine developers, in which case only development centers are revealed. Such small grain development improves resolving power, but decreases the number of developed silver grains, thus reducing sensitivity. The most satisfactory emulsion-developer combination under the conditions of the experiment appears to be Gevaert 307 emulsion developed for 2 min in D-19b. Data are also presented to facilitate the selection of the optimal emulsion-developer combination for various experimental situations.
QUANTITATIVE HISTOCHEMICAL ANALYSIS OF GLYCOLYTIC INTERMEDIATES AND COFACTORS WITH AN OIL WELL TECHNIQUE
Authors: MATSCHINSKY F. M. , PASSONNEAU J. V. , LOWRY O. H.
Published: April 2011

Quantitative histochemical measurements of glycolytic intermediates and cofactors in samples of the order of 0.1 µg dry weight have been made possible by the use of enzymatic fluorometric methods in combination with the technique of enzymatic cycling. In order to prevent evaporation of the necessarily small volumes of fluid and to avoid exposure to CO2 in the air, incubations are carried out under oil in wells drilled in Teflon. The general technique for conducting analyses in oil wells is described together with specific procedures for measuring glycogen, glucose, glucose 6-phosphate, uridine diphosphoglucose, fructose diphosphate, lactate, adenosine triphosphate, phosphocreatine and inorganic phosphate. The potential of the technique is illustrated by measurements of these compounds in each of nine discrete layers of the retina.
SUCCINYL LECITHIN AS A SUBSTRATE FOR SUCCINIC DEHYDROGENASE
Authors: ABDULLA Y. H. , ADAMS C. W. M. , BAYLISS O. B.
Published: April 2011

Succinyl lecithin has been used as substrate in the histochemical succinate-tetrazolium reductase system; it is as acceptable to the tissue system as is succinate. Cholesterol succinate, however, is not utilized by this system. It is inferred that the amphophilic nature of succinyl lecithin allows this substrate to penetrate lipid-rich mitochondrial membranes, whereas cholesterol succinate's more hydrophobic nature impedes its movement at such lipid-water interfaces. It must be emphasized that this study does not reveal whether or not succinyl lecithin is a physiologic substrate.
X-RAY DIFFRACTION STUDIES ON AMYLOID FILAMENTS
Authors: EANES E. D. , GLENNER G. G.
Published: April 2011

The filamentous protein component of amyloid-laden tissue was studied by x-ray diffraction procedures. The principal features of the x-ray pattern from nonoriented amyloid material consist of a sharp, intense ring at 4.75 Å overlaying a diffuse halo at 4.3 Å, and a broad and less intense ring at 9.8 Å. When oriented, the material gives a "cross-β" x-ray pattern. The x-ray findings are interpreted in terms of a "pleated sheet" structure formed by the amyloid polypeptide chain folding in a regular manner on itself such that adjacent chain segments are laterally arranged in an antiparallel manner. The x-ray patterns from oriented amyloid suggest further that the axes of the chain segments run transverse to the filament axis.
AN IMPROVEMENT OF THE HISTOCHEMICAL FLUOROSCENCE METHOD FOR MONOAMINES OBSERVATIONS ON VARYING EXTRACTABILITY OF FLUOROPHORES IN DIFFERENT NERVE FIBERS
Authors: BJÖRKLUND ANDERS , FALCK BENGT
Published: April 2011

The fluorophores formed from catecholamines in certain fiber structures are easily extracted from their tissue sites by xylene or hot paraffin, in contrast to the fluorophores in the ordinary adrenergic nerve fibers, which are fairly resistant to such media. A modified histochemical procedure is described, which reduces to a minimum the exposure of the specimens to hot paraffin and xylene. With this procedure, a higher sensitivity and reproductiveness of the fluorescence method is achieved in many structures. Thus hitherto unknown monoamine-containing structures have been detected, e.g., in the mammalian pituitary gland.
HISTOCHEMISTRY OF MYELIN VI. SOLVENT ACTION OF ACETONE ON BRAIN AND OTHER LIPID-RICH TISSUES
Authors: ADAMS C. W. M. , BAYLISS O. B.
Published: April 2011

The solvent action of acetone on frozen sections of brain and other lipid-rich tissues has been assessed by quantitative and chromatographic techniques. Under these histochemical conditions, acetone extracts free and esterified cholesterol, triglycerides and free fatty acids. Lecithin is not significantly extracted, while cephalins and sphingolipids are insoluble.
A STUDY OF OSMIUM TETROXIDE FIXATION
Authors: BURKL W. , SCHIECHL H.
Published: April 2011

The specific conditions of osmium fixation have been studied on gelatin gels and bovine pancreas. Protein (gelatin)-bound osmium can be quantitated by a modification of the Majumdar and Sen Gupta test, free and tissue (pancreas)-bound osmium by a modified Bahr test. Using these two methods, the depth of OsO4 penetration after increasing the times of fixation, the osmium concentration gradients and the total concentration of free and bound osmium at given spots within gelatin and tissue blocks have been determined. Warburg type experiments on suspended yeast cells and leukocytes demonstrate that 1% OsO4 stops cell respiration completely only after 40-min incubation. Formalin, 1%, is a more effective respiratory inhibitor.
THE EFFECTS OF LEAD AND FIXATIVES ON ACTIVITY OF GLUTAMIC OXALACETIC TRANSAMINASE
Authors: LEE SIN HANG , TORACK RICHARD M.
Published: April 2011

Lead oxalacetate, a primary reaction product precipitate for the visualization of the activity of glutamic oxalacetic transaminase in tissue sections, is stable at a slightly alkaline pH. At concentrations which are used for tissue fixation a slight inhibitory effect on glutamic oxalacetic transaminase activity is produced by acetone while a glutaraldehyde-formaldehyde mixture results in marked reduction of activity. The concentration of lead which is used to form the primary reaction product does not significantly inhibit this enzyme activity.
PURIFICATION OF GLUTARALDEHYDE ITS SIGNIFICANCE FOR PRESERVATION OF ACID PHOSPHATASE ACTIVITY
Authors: FAHIMI H. DARIUSH , DROCHMANS PIERRE , POPOWSKI A.
Published: April 2011

The inhibition of acid phosphatase activity in rat liver homogenates after fixation in different lots of commercial glutaraldehyde is determined and compared with the inhibition following fixation with a distilled product. It is shown that commercial glutaraldehydes inhibit more of the enzyme activity than the distilled product. The acidic products of oxidation of glutaraldehyde do not increase the inhibition of the enzymatic activity. The presence of high concentration of inorganic phosphates in different lots of commercial glutaraldehyde, as presented here, suggests that probably such impurities may be responsible for increased inhibition of phosphatase activity noted after fixation in commercial glutaraldehydes.
CYTOCHEMICAL DETECTION OF SITES OF ANTIBODY TO HORSERADISH PEROXIDASE IN SPLEEN AND LYMPH NODES
Authors: STRAUS WERNER
Published: April 2011

After repeated injection of small amounts of horseradish peroxidase into the perivertebral muscle and footpads of rabbits, certain sites in spleen and popliteal lymph nodes showed intense adsorption of antigen (horseradish peroxidase) during treatment of fixed tissue sections in vitro. The reaction occurred in certain cells, probably plasma cells, and was also positive in the reticulum extending between lymphocytes. These sites were considered to contain antibodies against horseradish peroxidase, since sections from the same block, not treated with antigen in vitro, and corresponding sections from nonimmunized rabbits did not give a similar reaction. The blood sera of rabbits which showed specific binding of antigen in the spleen caused approximately 60% inhibition of horseradish peroxidase activity, but no inhibition was caused by the blood sera of nonimmunized control animals.
ULTRASTRUCTURAL AND CYTOCHEMICAL OBSERVATIONS ON B-16 AND HARDING-PASSEY MOUSE MELANOMAS THE ORIGIN OF PREMELANOSOMES AND COMPOUND MELANOSOMES
Authors: NOVIKOFF ALEX B. , ALBALA ARLINE , BIEMPICA LUIS
Published: April 2011

The B-16 and Harding-Passey mouse melanomas were studied by light microscopy (tyrosinase, acid phosphatase, aryl sulfatase, thiamine pyrophosphatase and inosine diphosphatase activities) and electron microscopy (morphology and tyrosinase and acid phosphatase activities). Lysosomal enzyme activity is present in individual premelanosomes and melanosomes as well as in compound melanosomes. Acid phosphatase and tyrosinase activities are present in a Golgi-associated system of smooth endoplasmic reticulum (GERL) and small vesicles related to it. The acid phosphatase and tyrosinase activities of premelanosomes, and morphologic appearances, support the hypothesis that the granules arise from GERL. On the basis of the evidence presented, it is suggested that compound melanosomes arise within melanoma cells by autophagy.