bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative morphology and cytology of the olfactory organs in moray eels with remarks on their foraging behavior
Authors: Fishelson Lev 
Published: February 2005

AbstractBackground. This study compares the morphology and cytology of olfactory organs in moray eels (Muraenidae), particularly Siderea grisea and some species of the genera Echidna, Gymnothorax, and Lycodontis, fishes that are top predators in shallow‐water marine habitats. Some of the species search visually for food while others search by olfaction.Methods. The morays were collected in the Red Sea; the nasal olfactory organs were dissected and fixed in Bouin's solution for light‐microscopy, and 3.5% glutaraldehyde for electron‐microscopy studies.Results. In each studied species the olfactory rosettes are elongated structures situated in closed olfactory chambers between anterior tubular inlet nares and slit‐form posterior outlet openings. The double row of lamellae constituting these rosettes are round in Siderea and Echidna and elongated in the other species. They are attached at their base to a median raphe and range in number from 20 in the youngest observed Siderea to 168 in Gymnothorax of 1,500 mm total length. As in other teleosts, the lamellae are covered by a ciliated epithelium composed of three types of sensory cells: two of these, ciliated sensory neurons and ciliated supporting cells, differ in detail, length, and thickness of their cilia and intracellular rootlet system; the third type of sensory cells bears microvillae as well as cilia. Proximal, axonal extensions of the ciliated cells cross the basal lamina in bundles and combine to form fila olfactoria from which the two olfactory nerves extend towards the olfactory bulbs. Lateral extensions at the basal parts of these ciliated cells, the so‐called spines, cross the membranes of neighboring cells as dendrites, possibly changing part or all of the ciliated epithelium into an olfactory field. The density and number of sensory cells on the lamellae, as well as observed differences in their foraging behavior in nature and captivity, enable the morays to be divided into two groups: one group, in which the lamellae are richly covered with stereocilia, includes species of the genera Siderea and Echidna, that search for food by olfaction, and the second group, which has a great deal less cells with stereocilia and includes the studies species of Gymnothorax and Lycodontis, locates its food visually. © 1995 Wiley‐Liss, Inc.
Surface coat of sheep pulmonary intravascular macrophages: Reconstitution, and implication of a glycosyl‐phosphatidylinositol anchor
Authors: Singh Baljit , Ireland William P. , Minhas Kanwaljit , Atwal Onkar S. 
Published: February 2005

AbstractBackground: Pulmonary intravascular macrophages (PIMs) of sheep have a globular surface coat that facilitates endocytosis of tracer particles and Escherichia coli lipopolysaccharide, and is disrupted by the heparin and Brefeldin A treatments. The present study investigated the in vivo dynamics of the coat globules following heparin‐mediated removal, and the mechanism of globule organization on the plasma membrane of PIMs in vitro.Methods: Sheep were administered heparin at a dose of 50 IU/kg body weight IV, and euthanised at 30 min, 3, 6, 12, 48, and 120 hr (n = 2 for each treatment) after the treatment. Control sheep (n = 2) were injected with normal saline solution. The tissues were processed for an ultrastructural examination and acid phosphatase (ACPase) cytochemistry. Heparintreated lungs were subjected to morphometric analysis of the coat globules. Lung tissues from normal sheep (n = 2) were incubated with phosphatidylinositol‐specific‐phospholipase C (PIPLC; 2 IU/ml PBS) in vitro for 30 and 75 min.Results: Heparin study: The ultrastructural and morphometric data showed that the coat globules were removed at 30 min and reconstituted within 48 hr of the treatment. The PIMs showed priminent Golgi complexes associated with secretory vesicles, microtubules, and centriole between 3–12 hr of heparin treatment. Acid phosphatase cytochemistry also demonstrated secretory activity in the Golgi complexes of PIMs during the coat reconstitution. PIPLC study: The coat globules of PIMs were removed in a time‐dependent mode by the PIPLC treatment without damage to other cell organelles.Conclusions: This study demonstrates a time‐dependent reconstitution of the coat of PIMs in conjunction with secretory activity following heparinmediated removal, probably through sequenstration of the globules from blood. This ability is of functional significance as the coat mediates particle endocytosis by the PIMs. The results also suggest the presence of a glycosyl‐phosphatidylinositol (GPI) anchor in tethering of globules on the plasma membrane of PIMs to offer a structural basis for their integrity in pulmonary vascular flow. © 1995 Wiley‐Liss, Inc.
Rat hippocampal mossy fibers contain cholecystokinin‐like immunoreactivity
Authors: Chandy Joby , Pierce Joseph P. , Milner Teresa A. 
Published: February 2005

AbstractBackground: The possibility that mossy fiber endings in the rat hippocampal formation may contain cholecystokinin (CCK) was reexamined.Methods: For this, CCK‐immunoreactivity was examined by light and electron microscopy using the avidin‐biotin complex method.Results: At the light level, the topographical distribution of perikarya and processes with CCK‐like immunoreactivity (CCK‐LI) was similar to that previously described by others. Ultrastructural analysis of the dentate gyrus and CA3 region of the hippocampus revealed that some mossy fiber terminals contained CCK‐LI most often affiliated with large, dense‐core vesicles (DCV). Quantitative analysis revealed that 4–8% of the mossy terminal profiles examined (n = 350) contained CCK‐labeled DCVs, which corresponded to 0.03–0.2 labeled DCVs per 100 μm2 of neuropil.Conclusions: The presence of CCK‐LI within mossy fibers in the rat suggests that there is less species variability in peptide expression in this pathway than formerly believed. © 1995 Wiley‐Liss, Inc.
Potential neuroprotective effect of t‐butylhydroquinone against neurotoxicity—Induced by 1‐methyl‐4‐(2′‐methylphenyl)‐1,2,3,6‐tetrahydropyridine (2′‐methyl‐MPTP) in mice
Authors: Abdel‐Wahab M. H. 
Published: February 2005

AbstractDopaminergic damage inducing Parkinson's disease (PD) is ubiquitous neurodegenerative disorder, characterized by the progressive loss of dopaminergic neurons in the nigrostriatal pathways. The etiology and pathogenic factors implicated in dopaminergic damage are still unexplored to develop causal therapeutic strategies aimed to halt its progressive loss. The neurotoxicity induced by 1‐methyl‐4‐(2′‐methylphenyl)‐1,2,3,6‐tetrahydropyridine (2′CH3‐MPTP), which is more potent neurotoxic than MPTP in mice, is one of the most valuable models for analyzing pathological feature of dopaminergic damage. Herein, we investigated the neuroprotective effect of the potent antioxidant tertiary butylhydroquinone (TBHQ) against 2′CH3‐MPTP‐induced neurotoxicity in mice as well as the possible mechanism underlying such neurotoxicity. Male albino mice were injected with two doses of 2′CH3‐MPTP (20 mg/kg, i.p) for two consecutive days. Animals were killed after 2 weeks from the last dose of 2′CH3‐MPTP. Control animals received 10 mL/kg body weight i.p of distilled water. In both groups, brain stems containing the nigrostriatal pathways were dissected and reduced glutathione (GSH), malonyldialdehyde (MDA) contents, and superoxide dismutase (SOD) activity were estimated. Also, brain stem histopathological and histochemical changes were examined. The results of this study revealed that i.p injection of 2′CH3‐MPTP caused decrease in the brain stem content of GSH. On the other hand, the content of MDA and SOD activity was increased as compared with control groups. Also, 2′CH3‐MPTP showed severe histopathological changes including swelling of cytoplasm, interstitial edema, and complete loss of the neurons with reactive microglial proliferation and gliosis. Furthermore, histochemical examination of brain stem qualitatively showed depletion of dopaminergic neurons of nigrostriatum. Oral administration of TBHQ (100 mg/kg) prior to 2′CH3‐MPTP for 7 days caused normalization of GSH content and SOD activity and ameliorated the MDA content but still above the control value. Pretreatment with TBHQ slightly mitigated the histopathological and histochemical changes observed in 2′CH3‐MPTP‐treated mice. Based on these observations, it can be concluded that the antioxidant TBHQ has the ability to reverse the oxidative stress caused by 2′CH3‐MPTP in mice while failed to challenge the histopathological and histochemical changes induced by that toxicant. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:32–41, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20053
Usefulness of studies on the molecular mechanism of action of herbals/botanicals: The case of St. John's wort
Authors: Choudhuri Supratim , Valerio Luis G. 
Published: February 2005

AbstractThe use of herbals/botanicals has been gaining wide popularity in recent years in the United States as well as in other parts of the world. The mechanism of action of most of these herbals/botanicals has not been subjected to thorough scientific investigations. St. John's wort (Hypericum perforatum) represents a useful case study in this sense. Traditionally, it is used as a natural treatment for depression; however, in recent years its molecular mechanism of action has been elucidated by a number of laboratories across the world. Such studies have helped understand potential interactions of St. John's wort with drugs and other xenobiotics. St. John's wort activates a nuclear receptor called pregnane X receptor (PXR). PXR is a ligand‐activated transcription factor that induces a number of xenobiotic‐metabolizing enzymes and transporters including cytochrome P4503A4 (CYP3A4) in humans. Because CYP3A4 alone metabolizes about 60% of all clinically relevant drugs, induction of CYP3A4 may result in the rapid elimination of these drugs and a consequent reduction in drug efficacy. Ironically, such enzyme‐inducing effects may not produce any immediate adverse symptomatology in the person taking St. John's wort. Therefore, the case of St. John's wort should serve as a good example of the usefulness and importance of studies on the mechanism of action of the herbals/botanicals, particularly those with widespread use. Scientists, physicians, and other health professionals can make use of the knowledge from such studies as an additional risk management tool. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:1–11, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20057
The effect of bile salts on oxygen consumption, oxidative phosphorylation and ATP‐ase activity of mucosal homogenates from rat Jejunum and Ileum
Authors: Faust Robert G. , Wu Shih‐Min Liu 
Published: February 2005

AbstractThe conjugated bile salts, sodium taurocholate and glycocholate, inhibited oxygen consumption and uncoupled oxidative phosphorylation of mucosal homogenates from rat jejunum and ileum. These bile salts also were capable of increasing the ATP‐ase activity, in the presence of Na+ + K+ with Mg++, of both mucosal homogenates. Consequently, it was concluded from the results of this investigation that the previously observed decrease in ATP levels of rat jejunum and ileum, in the presence of bile salts, can be accounted for by both a complete uncoupling of oxidative phosphorylation and by an increase in ATP‐ase activity. Furthermore, the mechanism of bile salt inhibition of tissue ATP levels was discussed in relation to a regulatory role played by bile salts in the active transport of water soluble substances across the small intestine.
Possible role of Ca ions in the resting metabolism of frog sartorius muscle during potassium depolarization
Authors: Novotný I. , Vyskočil F. 
Published: February 2005

AbstractOxygen consumption and Ca exchangeability at different levels of potassium depolarization were studied in frog sartorius muscle. It was found that the changes in oxygen consumption parallel the changes in Ca exchangeability. Procaine (10−3 M) and CaCl2 (2.10−2 M) suppressed both extra oxygen consumption and Ca exchangeability at low values of depolarization. At higher values of depolarization procaine and CaCl2 differed in their action. Procaine favored inhibition of these processes, CaCl2 caused their activation. The effects of these compounds was not a result of a change in the membrane potential, since their effect on potassium depolarization was found to be small.Relations between oxygen consumption and Ca exchangeability similar to those observed at potassium depolarization seem to exist under conditions where caffeine was applied. It is proposed that the extra oxygen consumption caused by potassium depolarization or on application of caffeine and unaccompanied by mechanical changes is related to the release of Ca from its bound form. Oxygen consumption in isotonic sucrose solution was also studied, but some different data from the above were obtained.
The in vitro response of thymic lymphocytes of the pig to phytohemagglutinin
Authors: Weber W. T. 
Published: February 2005

AbstractThe response of thymic lymphocytes of the pig to phytohemagglutinin was studied with H3 thymidine in cultures, from 0–72 hours. At the beginning of the culture period 6–18% of lymphocytes were in DNA synthesis. during the first 24 hours a sharp decrease in the number of DNA synthesizing cells was observed in both pha and control cultures, although pha cultures consistently showed small but significantly greater numbers of DNA synthesizing cells. this was followed by a definite peak in DNA synthesis and mitotic response of a minority of the cells in pha cultures between 48–54 hours, whereas in control cultures activity ceased. in addition, a small proportion of the progeny of initially DNA synthesizing medium sized lymphocytes was apparently stimulated by pha and found in mitosis by 48 hours.It was concluded that the thymus contains a fraction of lymphocytes, not in the mitotic cycle, which are capable of being transformed by pha to mitotic activity. the data also suggests some stimulation of cells already in the mitotic cycle.
Isolation and characterization of an isoantigenic variant from a heterozygous mouse lymphoma in culture
Authors: Papermaster Ben W. , Herzenberg Leonard A. 
Published: February 2005

AbstractA cell line from a mouse lymphoma heterozygous at the chromosome region for the H‐2d and H‐2k alleles was originally obtained from a transplantable lymphoma in the (C3H × DBA/2)F1 hybrid (H‐2d/H‐2k) and cultured in vitro. The original cultured line, termed parent line, was susceptible to the cytotoxic action of antibodies directed against antigenic components of both the d and k alleles. The parent line also absorbed hemagglutinins from both anti‐d anti‐k antisera. A resistant, variant subline was selected from the original population by immunoselection in vitro with anti‐H‐2d antibody and complement in a cytotoxic system. After one year in continuous culture in the absence of selecting antisera, the variant subline was still resistant to the cytotoxic action of anti‐H‐2d antibody. Serologic analysis of the variant indicated that it had lost the D antigenic component of the d allele, had a reduced amount of the H component, controlled by both the d and k alleles, and had retained the K component of the k allele. Possible genetic mechanisms that might account for the emergence of the variant line are discussed. While the results do not necessarily support an analysis based on mitotic recombination, ascribing other mechanisms is also difficult because of aneuploidy in the cell line. Finally, the experiments point out the advantages of using in vitro immunoselective methods in the genetics of mammalian somatic cells.
5‐Hydroxytryptamine in frog's skin
Authors: Welsh John H. , Zipf Joyce B. 
Published: February 2005

AbstractThe amounts of 5‐hydroxytryptamine (5‐HT) in the skin of nine species of anurans were estimated by the fluorescence method. Relatively large quantities of 5‐HT were found in the dorsal skin of five species of semi‐terrestrial frogs, while in the skins of four highly aquatic species none, or only a trace, was found. Using the histochemical fluorescence method of Falck, 5‐HT was located in the granules of the venom glands of Rana pipiens, a semi‐terrestrial species, while no fluorescing glands were found in R. catesbeiana, a highly aquatic species. The results of Erspamer and others are discussed. It is suggested that the most probable role of 5‐HT in frog skin is that of defense against land predators.
The effect of fluoride and calcium ions upon the insulin plus lactate‐stimulated K uptake and respiratory rate of frog muscles
Authors: O'Niell K. E. , Manery J. F. , Dryden E. E. 
Published: February 2005

AbstractUsing paired frog muscles it was shown that fluoride caused no observable change in the rate of oxygen consumption in Ca++‐free Ringer's solution, but stimulated the rate in Ca++‐containing Ringer's; the obvious explanation for this stimulation is the spontaneous activity of the muscle caused by the rapid lowering of Ca++ ion concentration when fluoride was added. Fluoride had no effect on potassium movement in these experiments. In a Ca++‐free solution fluoride (0.03 M) inhibited the insulin + lactate‐stimulated oxygen consumption of muscles which had been adapted to the absence of calcium by overnight soaking. In Ca++‐containing Ringer's there was no net effect of fluoride, demonstrating the fact that the direct inhibition of oxygen consumption was cancelled by the indirect stimulation caused by the fluoride‐lowering of the Ca++ ion concentration. Fluoride depressed the IL‐induced K uptake but for this effect some calcium, albeit a very low concentration, was necessary. Fluoride did not alter the muscle glycogen concentrations.The only observable effect of calcium (in the absence of fluoride) was a rise in respiration caused by exposure to a sudden reduction in Ca++ ion concentration. Both the IL‐stimulated O2 rate and K uptake were independent of Ca++ ions since they occurred in Ca++‐free adapted muscles, in muscles exposed to a rapid reduction of Ca++ ions as well as in muscles in a Ca++‐containing Ringer's solution.
Microelectrode analysis of light responses in the brain of the cricket (Gryllus domesticus)
Authors: Dingle Hugh , Fox Stephen S. 
Published: February 2005

AbstractElectrical activity in response to light stimuli was recorded from the brain of the cricket (Gryllus domesticus) using stainless steel microelectrodes. Four basic types of elements were observed as follows: (1) units which registered ambient light intensity by frequency of firing as well as responding with transient changes in rate to stepwise increases or decreases in intensity; (2) units which fired at a higher frequency in dark than in light; (3) units which fired continuously at low level in light and responded with a transient high frequency burst to light off; and (4) units which responded with a brief burst to on and off, but tended to be “on‐dominant” or “off‐dominant.” Also observed were synchronized spikes in mushroom body responding primarily to light off, but also on occasion to light on, and often accompanied by single unit responses. The units registering intensity are probably homologous with units showing similar properties recorded from the visual systems of several other arthropods and usually referred to as “sustaining units.” On‐off, off, and dark units are also known from other forms. The mushroom body light responses were similar to synchronized spikes recorded in cockroach mushroom body following antennal stimulation.
Regeneration of sialic acid on the surface of Chinese hamster cells in culture. I. General characteristics of the replacement process
Authors: Kraemer Paul M. 
Published: February 2005

AbstractTreatment of cultured CHO cells with neuraminidase reduced the mean surface sialic acid density to less than 10% of pretreatment values. Upon return to culture the mean density returned to pretreatment values within 12‐‐16 hours. During the period of surface sialic acid deficiency, no effect on cell volume, cell division, or attachment and spreading of cells on glass could be discerned. Surface sialic acid regeneration occurred at the same rate in suspension and monolayer cultures. Cells treated with neuraminidase, then with 10 mM thymidine or 6 μg/ml actinomycin D, ceased division yet replaced their surface sialic acid at the usual rate. By contrast puromycin (50 μg/ml), while stopping cell division, caused rapid inhibition of the regeneration process. Puromycin did not prevent cells untreated with neuraminidase from maintaining their control amount of surface sialic acid per cell.
Effect of temperature on the activity of ribonuclease from Tetrahymena pyriformis
Authors: Lazarus Lawrence H. , Scherbaum Otto H. 
Published: February 2005

AbstractIntracellular ribonuclease from the ciliate Tetrahymena pyriformis GL was purified 10‐fold. After preheating for 20 minutes at 100°C of the ribonuclease preparation 80% of its activity was lost. Preheating under the same conditions, however, in the presence of RNA, did not affect the enzyme activity. Between 0°C and 41°C the apparent activation energy was 15,600 cal per deg. per mole.
Difference between medullary and cortical thymic lymphocytes of the pig in their response to phytohemagglutinin
Authors: Weber W. T. 
Published: February 2005

AbstractPig thymus tissue was cultured with organ culture techniques in the presence and absence of phytohemagglutinin in the culture medium. Morphologic and autoradiographic observations indicate that in the pig, lymphocytes capable of responding to phytohemagglutinin are located predominantly in the medulla of the thymus.
Immunogenetic analysis of microsomal and non‐microsomal lipoproteins from normal and malignannt mouse tissues for histocompatibility‐2 (H‐2) antigens
Authors: Palm Joy , Manson L. A. 
Published: February 2005

AbstractThe H‐2 antigenic properties of lipoprotein fractions from malignant (L‐5178Y leukemia) and normal (spleen, thymus, liver, kidney) mouse tissues have been studied by serological and immunological tests, and the results compared to the previously described activities of these fractions in homograft‐sensitization tests. Although, in general, the relative activities in the different assays parallel each other some notable exceptions were found. The non‐microsomal lipoproteins from leukemic tissue, inactive in homograft‐sensitization tests, did elicit H‐2 antibody. Also, the liver microsomal lipoproteins, which are inactive in homograft‐sensitization tests in amounts 400 × the minimal effective doses of spleen preparations, exhibited, in in vitro agglutinin‐inhibition tests, approximately one‐fourth the H‐2 activity of the latter. Other findings of note include the high antibody‐eliciting potency of the spleen and leukemia microsomal lipoproteins (15 μg protein was sufficient to initiate primary immunization and 1 μg protein to cause an anamnestic response); and the quantitive identity of H‐2 antigen activity of the microsomal lipoproteins from spleen and thymus.
Isolation and karyological characteristics of seven hybrids between somatic mouse cells in vitro
Authors: Yoshida Michihiro C. , Ephrussi Boris 
Published: February 2005

AbstractIn vitro hybridization of seven pairs of genetically different murine cell has been demonstrated by the use of karyological markers, and pure cultures of these hybrids have been isolated. All somatic hybrids showed a progressive loss of chromosomes during this proliferation in vitro.