bluuebunny/crossref_metadata_2025 huggingface dataset:
A new technique for staining sections and recovering celloidin film in high resolution autoradiography.
Authors: Pradal G , Barriere P , Mollat F , Lefranc G
Published: April 2011

Ultrathin sections are stained immediately after cutting by placing them in contact with staining solution and then placed on a slide covered by a celloidin film. This method largely avoids precipitates of heavy metals. The recovering of celloidin film is improved using a stainless steel basket. This technique is far more reliable than that involving use of a filter paper.
Immunocytochemical visualization of luteinizing hormone-human chorionic gonadotropin (LH-hCG) receptors in Leydig cells in primary culture.
Authors: Begeot M , Mombrial C , Dubois P M , Dubois M P , Dazord A , Haour F
Published: April 2011

Visualization of human chorionic gonadotropin (hCG) binding sites was obtained by immunocytochemical reaction on Leydig cells cultured in chemically defined medium. After a short in vitro incubation with hCG or luteinizing hormone (LH), the cells were fixed and the bound molecules were revealed using anti-hCG or anti-LH antisera. In both cases the immunocytochemical reaction appeared as granulations at the cell surface. After prolonged (48 hr) culture in the presence of 0.5, 5, or 50 ng/ml of hCG, the hormone receptor complex is still visible. Similarly, following short exposure to hCG (0.5 or 50 ng/ml) and one or two days of culture without hCG, the immunocytochemical reaction is still present. These observations suggest that the half-life of the bound hormone is very long. This in vitro system in which the amount and time of hormone exposure are precisely defined provides arguments in favor of a long-term maintenance of the receptor complexes at the cell surface.
Immunohistochemical demonstration of H2 antigens in mouse tissue sections.
Authors: Ponder B A , Wilkinson M M , Wood M , Westwood J H
Published: April 2011

The immunohistological demonstration of H2 antigens in cryostat sections of a wide variety of mouse tissues is reported. The purpose in developing the method was to use H2 antigens as cellular markers in studies of mouse chimeras. Monoclonal anti-H2 antibodies were used, either with a hapten-sandwich technique using biotin or arsanilate, or as direct enzyme conjugates. The direct antibody-enzyme conjugates were simpler to use, provided an intensity of specific staining which was comparable to that obtained with the hapten-sandwich systems, and gave fewer problems of background when simultaneous double staining was attempted. The results provide a description of the distribution of H2 antigens in many of these tissues. The intensity of H2 staining varied widely from tissue to tissue, but also within tissues and between individual mice of the same litter. Quantitation by autoradiography suggests that there is a fivefold variation in available H2 antigen between tissues which are stained strongly or weakly by our technique.
A comparative study of polyclonal and monoclonal antibodies for immunocytochemical localization of cytosolic aspartate aminotransferase in rat liver.
Authors: Lin C T , Chen L H , Chan T S
Published: April 2011

The rabbit antiserum and mouse monoclonal hybridoma antibody against porcine cytosolic aspartate aminotransferase (c-AAT) (or cytosolic glutamic oxaloacetic transaminase (c-GOT)) were produced and compared for the localization of c-AAT in rat liver. An indirect immunocytochemical technique was performed using peroxidase-conjugated goat immunoglobulin (Ig) G anti-rabbit IgG and peroxidase-conjugated rabbit IgG anti-mouse IgG as the second antibody. Rats were perfused with paraformaldehyde-lysine-periodate fixative and the liver fragments were immersed in 4% paraformaldehyde and transferred to 10% dimethyl sulfoxide overnight and subjected to cryostat sectioning. The rabbit IgG antibody, 3 individual monoclonal antibodies, and a mixture of these 3 monoclonal antibodies were applied to the tissue sections, respectively, using the same concentration. Under the same experimental conditions, the c-AAT was localized in each individual hepatocyte by both monoclonal and polyclonal antibodies. However, a mixture of three monoclonal antibodies gave stronger staining than a single monoclonal antibody; although two antibodies yield more intense staining than just one, it was still less intense than for three. The conventional rabbit polyclonal antibody against c-AAT produced more reaction product than the combined three monoclonal antibodies. It is concluded that for immunocytochemical study, the use of a single monoclonal antibody is sensitive enough to localize its tissue antigen under the present experimental condition. To obtain a stronger reaction product, a combination of several monoclonal antibodies, at least three or more, may give better staining.
Effects of endogenous antidiuretic hormone (ADH) on macrophage phagocytosis.
Authors: Fernandez-Repollet E , Opava-Stitzer S , Tiffany S , Schwartz A
Published: April 2011

Although several studies have indicated that antidiuretic hormone (ADH) enhances the phagocytic function of the reticuloendothelial system (RES) in shock syndromes, it remains unknown what influence ADH exerts upon the individual phagocytic components of this system. The present investigation was designed to evaluate the effects of endogenous ADH on the phagocytic activity of peritoneal macrophage cells. As a phagocytic stimuli, fluorescent methacrylate microbeads were injected intraperitoneally into Brattleboro (ADH deficient) and normal Long Evans rats in the presence and absence of exogenous ADH. Peritoneal cells were harvested 19-22 hr after the administration of the microbeads and the percent phagocytosis was determined in macrophage cells using a fluorescence-activated cell sorter (FACS II). Our results indicate that the percentage of peritoneal macrophages ingesting the fluorescent methacrylate microbeads was significantly reduced in the absence of ADH (Brattleboro rats: 5.4 +/- 0.6% versus Long Evans rats: 16.8 +/- 2.3%; p less than 0.001). In addition, our data demonstrate that exogenous administration of ADH significantly enhanced macrophage phagocytosis in Brattleboro (14.7 +/- 2.2%) and normal Long Evans (49.6 +/- 4.5%) rats. These data suggest, for the first time, that endogenous ADH might play a modulatory role in the phagocytic activity of a specific component of the RES, namely, the macrophage cell.
Combined quantitative cytophotometric method for staining indolyl and sulfhydryl groups and protein.
Authors: Nakae Y , Shono M , Ishizuka H
Published: April 2011

Sulfenylation with 2-nitrophenylsulfenyl chloride (NPS-Cl), which is specific for tryptophyl and cysteinyl residues in protein, was applied to quantitative histochemistry. By measurement of the absorbance values at 370 nm of sections stained with NPS-Cl, Beer-Lambert's law was found to hold for NPS staining. Treatment of NPS-stained sections with 2-mercaptoethanol (ME) (NPS-ME staining) resulted in sulfenylation of tryptophyl residues only. For determination of the amounts of tryptophyl and cysteinyl residues per unit of protein, protein staining with Coomassie Brilliant Blue (CB) was combined with NPS and NPS-ME staining. CB and NPS-CBB staining also followed Beer-Lambert's law. By measuring the absorbance values at 370 and 650 nm of doubly stained sections, the relative contents of tryptophyl and cysteinyl residues in various tissue proteins were calculated. This method will be useful for the investigation of changes in both protein amount and composition.
Enzyme modulation of the Golgi apparatus and GERL: a cytochemical study of parotid acinar cells.
Authors: Oliver C , Hand A R
Published: April 2011

The distribution of thiamine pyrophosphatase (TPPase) and acid phosphatase (AcPase) has been examined in resting parotid acinar cells as well as during decreased and increased secretory granule production. In resting acinar cells, TPPase activity was restricted to the trans Golgi saccules and AcPase activity was localized in GERL and immature secretory granules. Although secretory granule production is diminished during ethionine intoxication, no significant alteration in the distribution of either TPPase or AcPase was noted. However, marked changes in enzyme localization, especially of TPPase, occurred during accelerated secretory granule production. The alterations were essentially the same for all of the conditions studied (recovery from ethionine treatment, recovery from a protein depletion diet, secretory stimulation with isoproterenol, and postnatal maturation of the parotid gland). During maximal secretory granule production, TPPase activity was localized not only in the trans Golgi saccules, but also in GERL-like cisternae and immature secretory granules. The immature secretory granules were often in continuity with the GERL-like cisternae. At the same time that the TPPase activity was increased, the AcPase activity was frequently diminished. These modulations in enzyme activity provide evidence that GERL is derived from the trans Golgi saccule.
Ultrastructural identification of noradrenergic nerve terminals and vasopressin-containing neurons of the paraventricular nucleus in the same thin section.
Authors: Silverman A J , Hou-Yu A , Oldfield B J
Published: April 2011

Since many peptidergic cell groups receive a diverse and complex monoaminergic innervation, we have developed a double-label procedure to visualize a peptide and a catecholamine in the same ultrathin section. Radiolabeled norepinephrine (NE) is applied locally and its reuptake into NE terminals is demonstrated by ultrastructural radioautography. Controls in this and other studies demonstrate that the NE labels only NE (and possibly epinephrine) terminals and not dopaminergic or serotonergic terminals. In the same tissue, vasopressin is localized by immunocytochemistry on unembedded sections that are subsequently embedded in epoxy resins for thin sectioning. The procedure as described here shows that NE terminals in the periventricular zone of the paraventricular nucleus of the hypothalamus innervate both vasopressin-positive and vasopressin-negative structures. This technique is useful in determining the chemical connectivity of the hypothalamus.
Elimination of cross-reactivity to some component of erythrocytes in an antiserum to parathyroid hormone by absorption with fixed erythrocytes.
Authors: Rao L G , Murray T M , Heersche J N
Published: April 2011

Cross-reactivity to some component of rat erythrocytes with an antiserum to parathyroid hormone (anti-PTH) was detected in fixed demineralized sections of bone using the peroxidase-antiperoxidase method. The cross-reactivity was eliminated by the preabsorption of anti-PTH with fixed, washed rat erythrocytes. This technique provides an easy and rapid method with which to eliminate cross-reactivity to erythrocytes whenever such a situation is encountered in immunohistochemical procedures.
Localization of calcium in red blood cells.
Authors: Borgers M , Thone F J , Xhonneux B J , De Clerck F F
Published: April 2011

The distribution of calcium is demonstrated in human red blood cells (RBC) with a combined phosphate-pyroantimonate technique (PPA). Freshly collected blood and tissue biopsies were initially fixed in potassium phosphate-glutaraldehyde and the complexed calcium was subsequently visualized on Vibratome sections with potassium pyroantimonate. The majority of cells, both in isolated as well as "in situ" preparations, show a fine granular precipitate located at the inner leaflet of the plasma membrane. A minority of cells lack these membrane-associated deposits, exhibiting instead a random distribution of very fine precipitate in their cytoplasm. Capillary endothelial cells and pericytes are devoid of plasma membrane-bound precipitate. When irreversible crenation of RBC is induced by exposure to ionophore A 23187 and calcium, the sphero-echinocytes loose their membrane-bound precipitate, whereas the cells that retain their discocyte shape demonstrate the usual pattern of membrane-bound deposits. Contrarily, cells showing reversible shape changes induced by either A 23187-Ca2+ challenge, by adenosine triphosphate depletion during aging, or contact with lysolecithin, retain or regain the membrane-bound calcium. This cytochemical demonstrable calcium at the inner leaflet of the plasma membrane is probably bound to acidic phospholipids, since it is readily extractable with the nonionic detergent Triton X-100.
Apparent failure of 2-hydroxy-3-naphthoic acid hydrazide to block the periodic acid-Schiff reactivity of sialic acids. Implications for the PANFOPAS method.
Authors: Reid P E , Culling C F
Published: April 2011

Histochemical studies of the mechanism of staining of the periodic acid/2,-hydroxy-3-naphthoic acid hydrazide/Fast Black B/saponification/periodic acid-Schiff (PANFOPAS) method indicate that while 2-hydroxy-3-naphthoic acid hydrazide blocks the periodate engendered Schiff reactivity of vicinal diols unassociated with anionic groups, it fails to block such reactivity in sialic acid residues. It is suggested, therefore, that the positive Schiff staining observed following application of the PANFOPAS method to colonic epithelial mucins may be due to sialic acids without side chain substituents (or which are substituted at C7 or C9) in addition to sialic acids substituted at C8 (or which are di- or trisubstituted). Consequently the PANFOPAS method cannot be used to study the side chain substitution pattern of the sialic acids of epithelial mucins.
Demonstration of beta-adrenergic receptors in rat bronchiolar epithelial cells employing 9-amino-acridyl propranolol fluorescent microscopy.
Authors: Massaro G D , Davis L D
Published: April 2011

Prior work has provided ultrastructural evidence that beta-adrenergic agonists stimulate secretion by nonciliated bronchiolar epithelial (Clara) cells of the rat (J Clin Invest 67:345, 1981). However, since the lung is a multicellular organ it is not clear if the beta-agonists act directly on the Clara cell. The absence in Clara cells of beta-adrenergic receptors would indicate an indirect action of the beta-adrenergic agonists. In the present study, we used 9-amino-acridyl propranolol in an attempt to determine if beta-adrenergic receptors are present in rat bronchiolar Clara cells. Discrete, intense yellow fluorescent dots were identified microscopically in ciliated and in Clara cells of the rat. This anatomical localization of beta-adrenergic receptors supports the notion that beta-adrenergic agonists stimulate secretion by acting directly on Clara cells.
Immunocytochemistry with monoclonal anti-immunoglobulin as a developing reagent: application to immunoperoxidase staining and radioimmunocytochemistry.
Authors: MacMillan F M , Sofroniew M V , Sidebottom E , Cuello A C
Published: April 2011

The development of two monoclonal antibodies for use as second antibodies in immunocytochemistry is described. The antibodies are produced by mouse X mouse hybrid myelomas, and are both of the IgG type. The two antibodies, RB23 and ND13, were used to detect neurophysin by three-step peroxidase-antiperoxidase (PAP) immunostaining, and were "internally labeled" with 3H-lysine for the radioimmunocytochemical localization of neurophysin, substance P, and tyrosine hydroxylase using rabbit first antibodies. The binding sites of RB23 and ND13 on the rabbit IgG antibodies were determined by solid-phase radioimmunoassay, using allotype-specific rabbit serum to compete with RB23 and ND13. It was found that both RB23 and ND13 are directed against the B4 kappa-light-chain allotype. The immunocytochemical localization of adrenocorticotropic hormone and somatostatin with rabbit primary antibodies was not achieved with RB23 or ND13, and it is proposed that these antibodies are not of the B4 allotype. The findings demonstrate that monoclonal second antibodies can be useful general reagents for conventional immunocytochemistry as well as for radioimmunocytochemistry. Furthermore, allotype-specific monoclonal second antibodies may prove useful in the simultaneous immunohistochemical localization of more than one antigen in a given tissue section.
Cytochemical studies of myocardial adenylate cyclase after its activation and inhibition.
Authors: Slezak J , Geller S A
Published: April 2011

Incubation medium, as previously described (J Histochem Cytochem 27:774, 1979), was used to demonstrate the presence of adenylate cyclase (AC) in myocardium. NaF and ouabain were used to inhibit adenosine triphosphatases (ATP) and NaF and isoproterenol were used as activators of AC. The inhibitory effect of adenosine on AC was blocked by the addition of adenosine deaminase. The addition of tetramisol blocked the influence of the alkaline phosphatases on adenylyl imidodiphosphate hydrolysis. The use of these substances resulted in specific precipitation localized in junctional sarcoplasmic reticulum and sarcolemma. The reaction product was dramatically intensified after activation of AC by NaF or isoproterenol. Preincubation in 10-100 mM of propranolol, for 30 min, blocked AC stimulation by isoproterenol and prevented the appearance of the specific precipitate. The localization of specific precipitate in junctional sarcoplasmic reticulum and subsarcolemmal cisternae corresponds to the localization of Na+, K+ ATPase and may reflect the similar role that AC and Na+, K+ ATPase play in calcium release from sarcoplasmic reticulum of internal and peripheral couplings.
An improved method for freeze-fracture radioautography of tissues and cells, as applied to duodenal epithelium and thymic lymphocytes.
Authors: Kan F W , Kopriwa B M , Leblond C P
Published: April 2011

An improved method has been devised for the localization of radioactive substances to either one of the leaflets of cellular membranes. After tissue specimens are freeze-fractured and covered with a platinum-carbon replica, they are freeze-dried to allow coating with radioautographic emulsion at room temperature. After exposure at 4 degrees C and development, the emulsion is protected by layers of carbon and grease before the tissue underlying the replica is dissolved in sodium hypochlorite. The grease is removed in Freon 14 and the replica with its emulsion cover is mounted on a specimen grid for electron microscopic examination. The accuracy of radioactivity localization was demonstrated using 3H-thymidine-labeled liver by finding silver grains over the same sites after freeze-fracture as after thin section radioautography. Tests with 3H-methacrylate revealed that the interposition of a platinum-carbon replica decreased the radioautographic reaction by over 80%; hence, the need for long exposure. Only 67% of the silver grains came from radiation sources located beyond the upper 0.05 micron of the specimen and, therefore, the emulsion could be affected by radiation sources located not only within membrane leaflets but also in nearby cytoplasm. Thus, when 3H-fucose was injected into rats to locate newly formed glycoproteins within intestinal epithelium membranes, some of the silver grains found over E and P faces might be produced by radiation coming from the adjacent cytoplasm. To localize label within membrane leaflets in the absence of radiation sources in the cytoplasm, lymphocyte suspensions were incubated with 3H-concanavalin A at 0 degrees C. The plasmalemma radioactivity was then restricted to the two membrane leaflets, with 87-93% of the silver grains on the E leaflet and 7-13% on the P leaflet. It appears that, under these conditions, the technique provides adequate localization of radioactivity to the leaflets of the cell membrane.
Immunocytochemistry for LHRH neurons in the arcuate nucleus area of the rat: fact or artifact?
Authors: Kozlowski G P , Dees W L
Published: April 2011

Antisera to luteinizing hormone-releasing hormone (LHRH) generated against hapten-conjugates in which BSA (bovine serum albumin) is used as a carrier can contain both anti-LHRH and anti-BSA antibodies. Such antisera can cause the false-positive staining of neuronal cell bodies and other elements of the medial basal hypothalamus owing to the presence of anti-BSA, which cross-reacts with albuminoid substances within these cells. Differential blocking experiments using either BSA or LHRH or both BSA and LHRH as immunoabsorbents demonstrated that recent reports of LHRH-containing neurons in the medial basal hypothalamus of the rat have arisen from false-positive results due to the presence of anti-BSA within the anti-LHRH antisera used. Immunocytochemical evidence of LHRH-containing cell bodies in the medial basal hypothalamus (especially within the arcuate nucleus) of the rat remains unproven.
Immunocytochemical assays of amylase and chymotrypsinogen in rat pancreas secretory granules. Efficacy of using immunogold-labeled ultrathin cryosections to estimate relative protein concentrations.
Authors: Posthuma G , Slot J W , Geuze H J
Published: April 2011

An exploration was conducted as to whether the relative concentration of two intracellular proteins could be evaluated quantitatively from their labeling densities in ultrathin cryosections labeled with the immunogold technique. As a model rat pancreatic cells were used in which the content of amylase (Am) and chymotrypsinogen (Ch) was experimentally altered. Rats were fed either normal laboratory chow or food containing soybean trypsin inhibitor (STI), which affects the Am/Ch ratio in the tissues. The changes in Am and Ch protein levels and enzyme activities were measured biochemically in cell suspension homogenates or in zymogen granule fractions. Within 5 days a maximal change in the Am/Ch was observed as a result of adaptation to the STI diet. The Am/Ch ratio determined biochemically was compared with that from counts of gold particles bound to the respective protein in immunogold-labeled cryosections. The two data sets matched fairly well, indicating that the intensity of the immunoreaction is a reliable reflection of antigen concentration in this system.
Immunocytochemical detection of oncomodulin in tumor tissue.
Authors: Brewer L M , Durkin J P , MacManus J P
Published: April 2011

Using the rat hepatoma calcium-binding protein, oncomodulin, from Morris hepatoma 5123tc, an antiserum has been raised in rabbits useful for immunostaining of this tumor protein. The peroxidase-antiperoxidase (PAP) technique has been used to demonstrate oncomodulin in sections of Morris rat hepatomas 5123D, 5123tc, 7288Ctc, and 7777 fixed with Bouin's or Carnoy's fixatives, or using freeze substitution. Oncomodulin-specific staining was also shown by a hepatoma metastasis in lung. Optimal conditions for the indirect fluorescent antibody technique were established to demonstrate oncomodulin in virally transformed NRK cells (ASV-NRK). In both tumors and cultured neoplastic cells staining appeared which suggested that oncomodulin might occur in nucleus and cytoplasm. Normal untransformed tissues and uninfected cells did not show oncomodulin staining.
Immunoanatomic dissection of the human urinary tract by monoclonal antibodies.
Authors: Cordon-Cardo C , Bander N H , Fradet Y , Finstad C L , Whitmore W F , Lloyd K O , Oettgen H F , Melamed M R , Old L J
Published: April 2011

The immunoanatomy of the human kidney and urinary tract has been analyzed by a panel of mouse anti-human monoclonal antibodies that define specific domains and structures. The differentiation antigens detected by these monoclonal antibodies represent a series of glycoproteins characteristic of different cell types. They differ from the blood group antigens and appear to be distinct from other antigens previously described within the kidney or urinary tract. The antigens recognized by these monoclonal antibodies represent an immunohistologic dissection of the human nephron. These antibodies have a broad range of potential applications in studying embryogenesis and pathogenesis of nonneoplastic and neoplastic diseases of the human kidney and urothelium.
Topography and dynamics of receptors for acetylated and malondialdehyde-modified low-density lipoprotein in the plasma membrane of mouse peritoneal macrophages as visualized by colloidal gold in conjunction with surface replicas.
Authors: Robenek H , Schmitz G , Assmann G
Published: April 2011

The topography and dynamics of receptors for acetylated (acetyl) and malondialdehyde-modified (MDA) low-density lipoprotein (LDL) in the plasma membrane of cultured mouse peritoneal macrophages were investigated using a new technique. Modified LDL labeled with gold particles was used to visualize LDL receptors in the plane of the plasma membrane in platinum-carbon surface replicas of critical point-dried cells. It was found that the native distribution of unoccupied acetyl-LDL receptors is diffuse, whereas unoccupied MDA-LDL receptors are preclustered in the plasma membrane. Competition and double labeling experiments suggest the existence of two distinct classes of receptor sites for acetyl-LDL and MDA-LDL.
Glial fibrillary acidic protein in regenerating teleost spinal cord.
Authors: Anderson M J , Swanson K A , Waxman S G , Eng L F
Published: April 2011

Immunohistological and ultrastructural studies were carried out on normal and regenerating spinal cord of the gymnotid Sternarchus albifrons, and in the brain and spinal cord of the goldfish Carassius auratus, to examine the distribution of glial fibrillary acidic protein (GFAP) in these tissues. Sections of normal goldfish brain and spinal cord exhibited positive staining for GFAP. In normal Sternarchus spinal cord, electron microscopy has revealed filament-filled astrocytic processes; however, such astrocytic profiles were more numerous in regenerated cord. Likewise, while normal Sternarchus spinal cord showed only a small amount of GFAP staining, regenerated cords were strongly positive for GFAP. Positive staining with anti-GFAP was observed along the entire length of the regenerated cord in Sternarchus, and was especially strong in the transition zone between regenerated and unregenerated cord. Both regeneration of neurites and production of new neuronal cell bodies occur readily in such regenerating Sternarchus spinal cords (Anderson MJ, Waxman SG: J Hirnforsch 24: 371, 1983). These results demonstrate that the presence of GFAP and reactive astrocytes in Sternarchus spinal cord does not prevent neuronal regeneration in this species.
A perfusion-fixation procedure for the concurrent demonstration of Timm's, horseradish peroxidase (HRP), and acethycholinesterase (AChE) histochemistry.
Authors: Moss M B , Rosene D L
Published: April 2011

The sulfide-silver method of Timm has been a widely used histochemical technique to demonstrate the presence of heavy metals in biological tissue, particularly in the central nervous system. However, the use of this method or its several modifications results in less than optimal morphological preservation and requires embedding the tissue in paraffin or freezing it and cutting it directly onto slides with a cryostat. These procedures can decrease the sensitivity and limit the application of other histochemical procedures, particularly when experiments necessitate processing large specimens or reaction procedures require techniques using free-floating sections. A perfusion-fixation protocol is described that yields sufficient fixation to cut whole frozen blocks of tissue with a sliding microtome, permits the use of free-floating sections, and allows the concurrent demonstration of horseradish peroxidase and acetylcholinesterase histochemistry without loss of sensitivity. The method consists of a short initial exposure to a sodium sulfide solution followed by a prolonged exposure to a combined sulfide-aldehyde fixative solution.
Ultrastructural immunocytochemistry of particulate fractions using polyvinyl chloride microculture wells.
Authors: Wray B E , Sealock R
Published: April 2011

A method is described for immunoelectron microscopy of particulate subcellular fractions using polyvinyl chloride (soft) microculture wells as mechanical supports and reaction vessels. Appropriate quantities of particles are centrifuged onto the well bottoms, fixed and permeabilized if necessary, then labeled by standard procedures, fixed in glutaraldehyde and tannic acid, and prepared for thin section electron microscopy. The centrifugation, the fixations, and the embedment in Epon are discussed in detail.
Ultrastructural localization of nucleic acids through several cytochemical techniques on osmium-fixed tissues: comparative evaluation of the different labelings.
Authors: Bendayan M , Puvion E
Published: April 2011

Several cytochemical techniques, such as sodium tungstate, acid hydrolysis phosphotungstic acid (HAPTA), ethylenediaminetetraacetic acid (EDTA), RNase-gold, and osmium-ammine, have been applied for the ultrastructural demonstration of nucleic acids on sections of tissues fixed in glutaraldehyde postfixed with osmium tetroxide and embedded in Epon. In order to obtain specific results, the sections had to be treated with sodium metaperiodate prior to performing the labeling protocol. The results for each method were identical to those obtained on nonosmicated tissues; the main difference being the enhancement in the ultrastructural preservation, which allowed for higher resolution. In addition to these techniques, and for comparative evaluations, DNA was also revealed by the DNase-gold approach on nonosmicated tissue sections. The consistency in the results, obtained over the nucleus with either EDTA or the RNase-gold complex for revealing RNA and those obtained with either osmium-ammine or DNase-gold for revealing DNA, supports the high specificity of the RNase-gold, DNase-gold, and osmium-ammine techniques. Furthermore, these results demonstrate the possibility of performing various cytochemical techniques on tissues processed for routine electron microscopy.
Immunocytochemical study of collagen in epidermal growth factor (EGF)-treated osteoblastic cells.
Authors: Osaki Y , Tsunoi M , Hakeda Y , Kurisu K , Kumegawa M
Published: April 2011

The alteration of collagen components in clone MC3T3-E1 cells by epidermal growth factor (EGF) was investigated immunocytochemically, using antibodies to type I and type III collagens. EGF transformed those cells that had become more slender than those of control cultures. Type I and type III collagens were observed in the same cells in both EGF-treated and control cultures. Type I collagen was decreased by EGF, whereas type III collagen appeared to be increased. However, no cells with only type III collagen were observed, suggesting that EGF influences collagen metabolism in clone MC3T3-E1 cells.
Growth hormone releasing factor (GRF) immunoreactivity in human and rat gastrointestinal tract and pancreas.
Authors: Bosman F T , Van Assche C , Nieuwenhuyzen Kruseman A C , Jackson S , Lowry P J
Published: April 2011

Rabbit antisera were raised against a synthetic growth hormone releasing factor, which was originally isolated from a human pancreatic endocrine tumor (hpGRF-44). The antisera obtained showed no significant cross-reactivity with a variety of neurohormonal peptides. In addition to its occurrence in the human, but not in the rat, hypothalamus, hpGRF-44-like immunoreactivity was identified in human gastric antrum and human as well as rat pancreatic islets, using an indirect immunoperoxidase technique. Staining of serial sections and double staining revealed that in the gastric antrum the immunoreactivity was largely confined to gastrin (G) cells, whereas in pancreatic islets polypeptide (pp) cells were reactive. The physiological significance of these findings remains to be established.
Bombesin/gastrin-releasing peptide (GRP)- and Met5-enkephalin-Arg6-Gly7-Leu8-like immunoreactivities in small intensely fluorescent (SIF) cells and nerve fibers of rat sympathetic ganglia.
Authors: Helén P , Panula P , Yang H Y , Rapoport S I
Published: April 2011

Superior cervical and hypogastric ganglia were removed from rats that had been perfused with a mixture of 4% paraformaldehyde and 0.25% glutaraldehyde. Specific antisera against Met5-enkephalin-Arg6-Gly7-Leu8 (MEAGL) and bombesin/gastrin-releasing peptide (BN/GRP) were used in the immunofluorescence procedure. In hypogastric ganglia, a subpopulation of small intensely fluorescent (SIF) cells, as identified by their aqueous aldehyde (Faglu)-induced fluorescence, showed MEAGL- and BN/GRP-like immunolabeling. SIF cells in the superior cervical ganglia were unlabeled. In both ganglia, varicose nerve fiber networks and nerve terminals surrounding principal ganglion cells showed MEAGL- and BN/GRP-like immunoreactivities. Unlabeled SIF cells often were in close contact with nerve fibers that had MEAGL-like immunolabeling. Immunoreactivities against MEAGL- and BN/GRP-like neuropeptides in nerve fibers and terminals suggest a neurotransmitter or neuromodulator role for these peptides. In addition, labeling in SIF cells implies their possible endocrine function.
Scanning electron microscopy and X-ray microprobe analysis in detection of acetylcholinesterase in cultured embryonal carcinoma cells.
Authors: Rechardt L , Lehtinen S , Wartiovaara J
Published: April 2011

Mouse F9 cells, induced by retinoic acid and dibutyryl cyclic adenosine monophosphate (cAMP) to differentiate into neural-type cells, were incubated for localization of specific acetylcholinesterase (AChE) activity according to the Karnovsky-Roots method where the final enzymatic reaction product is crystalline cupric ferrocyanide and cuprous thiocholine iodide. By scanning electron microscopy (SEM) neural-type cells with long processes were seen. Most of these cells exhibited crystalline precipitates on their surface that in microprobe analysis contained copper, iron, and sulfur. These elements were also detected in some of the neural-type cells that had no visible surface precipitates. Thus, the X-ray analysis also revealed intracellular enzymatic activity. Undifferentiated rounded cells, devoid of AChE activity at the light microscope level, did not show any surface precipitates by SEM and lacked copper, iron, and sulfur emission peaks in the elementary analysis. These results demonstrate that elementary analysis of cytochemical enzymatic reaction products by SEM can be used in identifying cells.
Cytochemical staining of the endoplasmic reticulum and glycogen in mouse anterior pituitary cells.
Authors: Cataldo A M , Broadwell R D
Published: April 2011

The endoplasmic reticulum (ER) and glycogen in secretory cells of anterior pituitary glands from control and fasted mice were investigated ultrastructurally using cytochemical staining techniques. Potential enzyme cytochemical markers for the ER included glucose-6-phosphatase (G6Pase) and nucleoside diphosphatase (NDPase) activities. Presumptive glycogen particles were identified in tissue postfixed in 1% osmium tetroxide-1.5% potassium ferrocyanide or in ultrathin sections poststained with periodic acid-thiocarbohydrazide-silver proteinate. The ER appeared to be related structurally and cytochemically to the nuclear envelope and cis Golgi saccules. Similar relationships between the ER and the trans Golgi saccules or GERL were not observed. In anterior pituitary glands from control mice, G6Pase activity was prominent within the lumen of the ER, nuclear envelope, and cis Golgi saccules of all cells; reaction product was absent in the trans Golgi saccules and in GERL. G6Pase activity was sparse to non-existent in anterior pituitary cells from fasted mice. The cytochemical reaction utilizing the Gomori lead capture method indicated that G6Pase in anterior pituitary cells may function as a phosphohydrolase for converting glucose-6-phosphate to glucose. Cytochemical localization of NDPase activity was not evident in the ER; reaction product was localized consistently in one or two trans Golgi saccules and occasionally in GERL and nascent secretory granules. Presumptive glycogen particles in each of the different secretory cell types from control mice appeared as 20-30 nm wide, electron-dense particles scattered as single entities throughout the cytoplasm. Anterior pituitary glands from fasted mice exhibited conspicuous and numerous clumps of glycogen particles in addition to scattered particles in all cell types except corticotrophs, which appeared to be devoid of glycogen. Glycogen particles were absent in anterior pituitary cells incubated in a medium containing diastase. Our results suggest that in anterior pituitary cells of the mouse: 1) the phosphohydrolytic activity of G6Pase is a reliable cytochemical marker for the ER; 2) the ER is associated morphologically and cytochemically with the cis face but not with the trans face of the Golgi apparatus or with GERL; 3) some glucose-6-phosphate, a possible substrate for G6Pase in vivo, may be derived indirectly from glycogen stores; and 4) modulations in G6Pase activity and glycogen storage during fasting may reflect an alteration in energy metabolism.
Histochemical localization of gamma glutamyl transpeptidase in the paranodal region of peripheral nerve.
Authors: Mrsulja B J , Gulati A K , Zalewski A A
Published: April 2011

Gamma glutamyl transpeptidase (GGT), an amino acid transport enzyme, was investigated in normal and degenerated sciatic nerve of rat. The enzyme activity, which is considered to be a marker for cerebrovascular endothelium, was found to be absent in microvessels of normal and degenerated nerves. In the perineurium of normal nerve, GGT activity was faint, while in degenerated nerve, it increased. The most striking finding of this study was the observation of GGT activity at the paranode of each normal myelinated axon. It is interesting that after axotomy (8 weeks), no GGT activity was observed in the Schwann cells of degenerated nerve. Thus, Schwann cell plasmalemma contributed to GGT staining only when this cell was in contact with an axon mature enough to cause it to produce myelin. We conclude that, in peripheral nerve, transmembrane amino acid transport is apparently regional and associated with the paranodal region of myelinated nerve fibers.
Catecholaminergic and GABAergic anatomical relationship in the rat substantia nigra, locus coeruleus, and hypothalamic median eminence: immunocytochemical visualization of biosynthetic enzymes on serial semithin plastic-embedded sections.
Authors: Berod A , Chat M , Paut L , Tappaz M
Published: April 2011

The visualization of protein antigens has been performed on semithin sections embedded in Araldite. After partial removal of the resin and a light proteolytic treatment of the tissue we were able to localize several biosynthetic enzymes: tyrosine hydroxylase (TH), phenylethanolamine N-methyltransferase (PNMT), and glutamic acid decarboxylase (GAD), which are, respectively, markers of catecholaminergic, adrenergic, gamma-aminobutyric acid (GABA)ergic systems. This technique afforded a high resolution of light microscopy details and immunostaining of TH, GAD, and PNMT on serial sections enabled us to compare with great precision GABAergic and adrenergic innervations in the rat locus coeruleus. In addition, it allows us to study the possible relationship between these terminals and the noradrenergic neurons. We also compared the general pattern of distribution of TH- and GAD-positive endings in the hypothalamic median eminence. The preliminary results obtained with this technique revealed some interesting facts previously unseen when preparations with lower histological resolution were used.
The sessile drop method for immunohistochemical processing of unmounted sections of nervous tissue.
Authors: Nadelhaft I
Published: April 2011

A novel method for the immunohistochemical processing of free-floating tissue sections is described. Sections are immersed within drops of solution arranged on a hydrophobic surface. The procedure consists of sequentially suctioning away one fluid drop and replacing it by another, while the section remains in place. The technique permits easy testing of different antiserum dilutions, comparisons among different immunohistochemical protocols, and comparison of different antisera on serial tissue sections. Comparison is made to processing mounted sections.
Electron microscopic localization of neuron-specific enolase in rat and mouse brain.
Authors: Vinores S A , Herman M M , Rubinstein L J , Marangos P J
Published: April 2011

The cellular distribution and intracellular localization of neuron-specific enolase (NSE) has been studied by electron microscopic immunocytochemistry in the brain of the rat and of the mouse. Although the intensity of staining was less in the mouse, the same structures were positive in both species. In the cerebrum, the neuronal perikarya and dendrites were intensely stained, but staining was almost entirely absent in the presynaptic terminals. The deep neurons of the brain stem were also positive. In the cerebellum, perikarya, axons, and parallel fibers of the granule cell neurons were stained as were the synaptic vesicles and presynaptic membranes of the synapses between the parallel fibers and the Purkinje cell dendrites. Golgi cell dendrites, basket cells and their axons, and mossy fibers were also positive. In contrast, the Purkinje cells including their dendrites, and the climbing fibers that formed synapses with the Purkinje cell dendrites were not stained. The majority of the myelinated axons in both the cerebrum and the cerebellum did not stain, but the fibrillary astrocytic processes between myelinated axons in the white matter did. Oligodendroglia, protoplasmic astrocytes, Bergmann glia, astrocytes investing capillaries, and vascular endothelial cells were negative for reaction product. In the positively staining cells and their processes, the positivity was dispersed throughout the cytoplasm and corresponded most closely to the distribution of ribosomes, the granular endoplasmic reticulum, and microtubules. Nuclei, mitochondria, the cisternae of the Golgi complex, myelin lamellae, and most membranes were not stained.
Entrance of cholera enterotoxin subunits into thymus cells.
Authors: Tsuru S , Matsuguchi M , Watanabe M , Taniguchi M , Zinnaka Y
Published: April 2011

Analysis of the staining of cholera enterotoxin on the surface of cells with specific antibodies against each subunit of cholera enterotoxin, using a fluorescence-activated cell sorter and electron microscopy, showed that not only subunit A but also subunit B penetrates the cell membrane. The detection of subunits inside the cell was facilitated by the use of saponin, an agent that increases membrane permeability.
Identification of glycoprotein storage diseases by lectins: a new diagnostic method.
Authors: Alroy J , Orgad U , Ucci A A , Pereira M E
Published: April 2011

The specific diagnosis of glycoprotein storage diseases is made by demonstrating a deficiency in enzyme activity or an elevation of undegraded oligosaccharides in cells or body fluids. Prospective sampling and expensive specialized biochemistry, which is also time consuming, are required for such studies. We used lectin reagents on paraffin-embedded tissue sections to identify the specific sugars in undegraded stored substances. We studied 22 cases of glycoprotein storage diseases and differentiated histochemically between alpha- and beta-mannosidosis, fucosidosis, and sialisidosis. Cells affected with alpha-mannosidosis stained with Concanavalia ensiformis (Con A), Triticum vulgaris (WGA), and succinyl-WGA (S-WGA), while beta-mannosidosis cells did not stain with any of the lectins used. In fucosidosis the affected cells stained with Ulex europeus-I (UEA-I), while sialisidosis-affected cells stained with WGA, and in three cases with Arachis hypogea (PNA). This study indicates that lectin histochemistry provides a reliable specific diagnostic pattern for some glycoprotein storage diseases using a simple and inexpensive method.
Stepwise amplified immunoperoxidase (PAP) staining. I. Cellular morphology in relation to membrane markers.
Authors: Lansdorp P M , van der Kwast T H , de Boer M , Zeijlemaker W P
Published: April 2011

A novel procedure for the assay of monoclonal antibodies is described. The technique is based on a combination of three principles. Unlabeled (sheep) antiserum to mouse immunoglobulin (Ig) and complexes of peroxidase with mouse monoclonal antiperoxidase (monoclonal PAP complexes) are used as reagents in a variant of the unlabeled antibody enzyme (PAP) method, described by Sternberger. The amount of peroxidase eventually bound to a monoclonal antibody can be varied over a wide range by repetition of incubation cycles with anti-mouse Ig and monoclonal PAP complexes. During the assay, incubations and wash steps are performed by immersion of whole slides. The influence of repetitive incubation cycles with anti-mouse Ig and monoclonal PAP complexes on background staining and detection of monoclonal antibodies at low concentrations was quantitated in a model system. At a given primary antibody concentration, a linear relationship was found between peroxidase activity and the number of incubation cycles. Application of the technique to the detection of monoclonal antibodies bound to cell-surface antigens is described. Peripheral blood cells were labeled in suspension with monoclonal antibodies. Cytocentrifuge preparations of labeled cells were prepared, and such preparations were fixed before stepwise-amplified PAP staining. Cells showed intense specific staining. Morphological detail of stained and unstained cells is preserved, allowing morphological analysis of labeled cells and rapid analysis of monoclonal antibody specificity. Because the reagents used in the assay can be produced in large quantities with uniform quality, the technique can be readily automated. This, together with the possibility to increase the sensitivity of antibody detection in a controlled, stepwise fashion to levels that cannot be reached with "single-step" techniques, may further expand the applications of monoclonal antibodies.
Binding of GRP(14-27) but not bombesin or GRP(1-27) to hypothalamic magnocellular elements: an immunohistochemical study.
Authors: Panula P A , Cosenza-Murphy D , Yang H Y , Costa E
Published: April 2011

Bombesin, gastrin-releasing peptide (1-27), and gastrin-releasing peptide (14-27) abolished the specific immunocytochemical staining revealed by antiserum directed to the C-terminus of gastrin releasing peptide (GRP) and bombesin (BN) in rat hypothalamus. When the antiserum was preabsorbed with GRP(14-27), a strong reaction appeared in hypothalamic magnocellular neurons. This staining of magnocellular elements was produced by lower concentrations of GRP(14-27) than were needed to block immunocytochemical staining revealed by the antiserum in other hypothalamic locations. The distribution of GRP(14-27)-induced immunostaining was similar to that of neurophysin. Since only GRP(14-27) but not GRP(1-27) or bombesin was found to bind to magnocellular cells, it was concluded that binding was due to the N-terminus of GRP(14-27), which resembles the structure of oxytocin and vasopressin. In agreement with this, oxytocin and vasopressin were found to prevent the binding of GRP(14-27) to magnocellular cells. The similarity in localization and the effect of oxytocin and vasopressin suggest that GRP(14-27) may bind to neurophysin at low concentrations. The results suggest that enhancement of staining after preabsorption of antisera with antigens must be interpreted with care. Enhancement can occur at antigen concentrations lower than those required to block the immunostaining. These results fail to support the premise that antigen-induced enhancement of staining is due to antigen binding to specific receptors and subsequent detection of the receptor-bound antigen with the antiserum.
A routine method for contrasting elastin at the ultrastructural level.
Authors: Franc S , Garrone R , Bosch A , Franc J M
Published: April 2011

A reliable, simple, and inexpensive method for ultrastructural investigation of elastin is described. This method uses uranyl acetate dissolved in absolute methanol, followed by an optional lead citrate counterstain. The procedure was tested on a number of animal and human tissues that had been fixed and processed differently.