Types Of Immunoreactive Cells Research Articles

Research progress of tumor-infiltrating lymphocytes in malignant hematological diseases

In recent years, immunotherapy has been progressing rapidly in tumor treatment, among which, adoptive immunotherapy of immunologically active cells has also gained increasing attention in the treatment of malignant hematological diseases. Tumor-infiltrating lymphocytes are a heterogeneous class of T-cell-based lymphocytes with high heterogeneity. As an important component of the tumor microenvironment, TILs are crucial in the development of malignant tumors. TILs are a new type of immunoreactive cells discovered after lymphokine-activated killer cells, which can show high specificity and efficacy without the need for large amounts of interleukin-2. Tumor immunotherapy with TILs has shown encouraging results and is valuable in determining patient prognosis. In this paper, we review the composition and characteristics of TILs and their progress in malignant hematologic diseases.

Ependymal and Neural Stem Cells of Adult Molly Fish (Poecilia sphenops, Valenciennes, 1846) Brain: Histomorphometry, Immunohistochemical, and Ultrastructural Studies.

This study was conducted on 16 adult specimens of molly fish (Poecilia sphenops) to investigate ependymal cells (ECs) and their role in neurogenesis using ultrastructural examination and immunohistochemistry. The ECs lined the ventral and lateral surfaces of the optic ventricle and their processes extended through the tectal laminae and ended at the surface of the tectum as a subpial end-foot. Two cell types of ECs were identified: cuboidal non-ciliated (5.68 ± 0.84/100 μm2) and columnar ciliated (EC3.22 ± 0.71/100 μm2). Immunohistochemical analysis revealed two types of GFAP immunoreactive cells: ECs and astrocytes. The ECs showed the expression of IL-1β, APG5, and Nfr2. Moreover, ECs showed immunostaining for myostatin, S100, and SOX9 in their cytoplasmic processes. The proliferative activity of the neighboring stem cells was also distinct. The most interesting finding in this study was the glia–neuron interaction, where the processes of ECs met the progenitor neuronal cells in the ependymal area of the ventricular wall. These cells showed bundles of intermediate filaments in their processes and basal poles and were connected by desmosomes, followed by gap junctions. Many membrane-bounded vesicles could be demonstrated on the surface of the ciliated ECs that contained neurosecretion. The abluminal and lateral cell surfaces of ECs showed pinocytotic activities with many coated vesicles, while their apical cytoplasm contained centrioles. The occurrence of stem cells in close position to the ECs, and the presence of bundles of generating axons in direct contact with these stem cells indicate the role of ECs in neurogenesis. The TEM results revealed the presence of neural stem cells in a close position to the ECs, in addition to the presence of bundles of generating axons in direct contact with these stem cells. The present study indicates the role of ECs in neurogenesis.

Atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging of Neospora caninum-infected cell monolayers.

Neospora caninum is an obligate intracellular protozoan parasite of the phylum Alveolata (subphylum Apicomplexa) which has not been studied extensively in a biochemical context. N. caninum is a primary cause of reproductive disorders causing mummification and abortion not only in cattle but also in other small ruminant species resulting in a substantial economic impact on the livestock industry. In canids, which are the final hosts of N. caninum, clinical disease includes neuromuscular symptoms, ataxia, and ascending paralysis. Fatal outcomes of neosporosis have also been reported depending on the host species, age and immune status, however, its zoonotic potential is still uncertain. Therefore, N. caninum should be thoroughly investigated. Matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry (MS) and MS imaging (MSI) were used, combined with high-performance liquid chromatography (HPLC) to investigate these intracellular parasites. The aim of this study was to identify molecular biomarkers for N. caninum tachyzoite-infected host cells and to further clarify their functions. By atmospheric-pressure scanning microprobe MALDI MS(I), sections of N. caninum-infected and non-infected host cell pellets were examined in order to determine potential markers. In vivo, N. caninum infects different types of nucleated cells, such as endothelial cells which represent a highly immunoreactive cell type. Therefore, primary bovine umbilical vein endothelial cells were here used as a suitable infection system. For comparison, the permanent MARC-145 cell line was used as an additional, simplified in vitro cell culture model. HPLC-tandem MS (HPLC-MS/MS) experiments combined with database search were employed for structural verification of markers. The statistically relevant biomarkers found by MS and identified by HPLC-MS/MS measurements were partly also found in infected monolayers. Marker signals were imaged in cell layers of N. caninum-infected and non-infected host cells at 5µm lateral resolution.

Reelin Immunoreactivity in the Adult Spinal Cord: A Comparative Study in Rodents, Carnivores, and Non-human Primates.

Reelin is a large extracellular matrix (ECM) glycoprotein secreted by several neuronal populations in a specific manner in both the developing and the adult central nervous system. The extent of Reelin protein distribution and its functional role in the adult neocortex is well documented in different mammal models. However, its role in the adult spinal cord has not been well characterized and its distribution in the rodent spinal cord is fragmentary and has not been investigated in carnivores or primates as of yet. To gain insight into which neuronal populations and specific circuits may be influenced by Reelin in the adult spinal cord, we have conducted light and confocal microscopy study analysis of Reelin-immunoreactive cell types in the adult spinal cord. Here, we describe and compare Reelin immunoreactive cell type and distribution in the spinal cord of adult non-human primate (macaque monkeys, Macaca mulatta), carnivore (ferret, Mustela putorius) and rodent (rat, Rattus norvegicus). Our results show that in all three species studied, Reelin-immunoreactive neurons are present in the intermediate gray matter, ventricular zone and superficial dorsal horn and intermedio-lateral nucleus, while positive cells in the Clarke nucleus are only found in rats and primates. In addition, Reelin intermediolateral neurons colocalize with choline acetyltransferase (ChAT) only in macaque whilst motor neurons also colocalize Reelin and ChAT in macaque, ferret and rat spinal cord. The different expression patterns might reflect a differential role for Reelin in the pathways involved in the coordination of locomotor activity in the fore- and hind limbs.

The topography and proliferative activity of cells immunoreactive to various growth factors in rat femoral bone tissues after experimental fracture and implantation of titanium implants with bioactive biodegradable coatings.

Biodegradable implant coatings promote proliferation and expression of BMP-2, VEGF, and TGF-β2 genes and enhance BMP-2, VEGF, and TGF-β2 regulatory effects at different stages of reparative osteogenesis. To study the topography and ratio of PCNA-, VEGF-, BMP-2-, and TGF-β2-immunoreactive cells in rat femoral bone after closed fracture and implantation of titanium implants with biodegradable calcium phosphate and hydroxyapatite coatings. Standard titanium implant screws and similar implants with bioactive coatings were used. A total of 18 rats were randomly divided into three groups, two experimental and a control one. The rats in the first experimental group were implanted with implants without specific coating, while those in the second group, with implants with specific coatings. The control rats were subjected to the same fracture as the experimental ones without subsequent implantation. On days 7, 14, and 30 of experiment, the rats were sampled for histological examination. Histological sections were prepared and processed for PCNA, BMP-2, VEGF, and TGF-β2 immunoreactivity. In the regeneration zone, PCNA-immunoreactive cells substantially outnumbered other immunoreactive cell types. During the first two weeks after fracture, in the immediate vicinity of implant surface, the rate of VEGF production increased in osteoblast subpopulations and level of TGF-32 immunoreactivity decreased in chondroblasts. The level of TGF-32 was maximum on day 30 of experiment. BMP-2-immunoreactive osteocytes were found in the zone of external general plates. They accumulated at implants with calcium phosphate coating. Their number gradually increased by day 30 of experiment. The present data suggest that biodegradable implant coatings promote proliferation and expression of BMP-2, VEGF, and TGF-β2 genes and enhance BMP-2, VEGF, and TGF-β2 regulatory effects at different stages of reparative osteogenesis.

Regional differences in the density of Langerhans cells, CD8-positive T lymphocytes and CD68-positive macrophages: a preliminary study using elderly donated cadavers.

To provide a better understanding of the local immune system in the face and external genitalia, i.e., the oral floor, lower lip, palpebral conjunctiva, anus and penis, we examined the distribution and density of CD1a-positve Langerhans cells, CD8-positive suppressor T lymphocytes and CD68-positive macrophages using specimens from 8 male elderly cadavers. The density of Langerhans cells showed an individual difference of more than (or almost) 10-fold in the lip (oral floor). In the oral floor, Langerhans cells were often spherical. Submucosal or subcutaneous suppressor lymphocytes, especially rich in the oral floor and penile skin, migrated into the epithelium at 4 sites, except for the anus. In the conjunctiva, macrophage migration into the epithelium was seen in all 8 specimens. The density of suppressor lymphocytes showed a significant correlation between the oral floor and the lip (r=0.78). In contrast, the anal and penile skins showed no positive correlation in the density of all three types of immunoreactive cells examined. Overall, irrespective of the wide individual differences, the oral floor and conjunctiva seemed to be characterized by a rich content of all three cell types, whereas the penile skin was characterized by an abundance of suppressor lymphocytes. Based on the tables, as mean value, the relative abundance of three different cell types were as follows; CD1a-positive Langerhans cells (anus), CD8-positive lymphocytes (penis), and CD68-positive macrophages (lip). The present observations suggest that the local immune response is highly site-dependent, with a tendency for tolerance rather than rejection.

Identification and characterization of gastrointestinal hormone immunoreactive cells in the skin and parotoids of Chinese toad Bufo gargarizans.

The skin and skin secretion of Chinese toad Bufo gargarizans have long been used in traditional Chinese medicine. However, the exact types and location of bioactive substances in Bufo gargarizans skin still have not been fully elucidated. The aim of the study was to investigate the distribution and density of six types of gastrointestinal (GI) hormone immunoreactive (IR) cells in the skin and parotoids of Bufo gargarizans. Immunohistochemistry was used for qualitative and semiquantitative analysis of GI hormone presence in the dorsal and ventral skin, and parotoids of eight adult Chinese toads. Six types of IR cells were found: serotonin (5-HT), glucagon (GLU), gastrin (GAS), somatostatin (SS), pancreatic polypeptide (PP) and neuropeptide Y(NPY) IR cells. They were mainly present in the epidermis and skin glands. 5-HT-IR cells were distributed in all layers of epidermis and glands, with higher density in the glands. Glucagon was prominently expressed in the epidermis and the bottle-shaped glands of parotoids; however, it was not present in the granular glands of skin and parotoids. The distributions of GAS and SS-IR cells were similar since they were present mainly in mucous, granular and bottle-shaped glands, while these cell types were absent in the differentiated glands of parotoids. PP-IR cells were predominant in the granular glands and the bottle-shaped glands. The expression of NPY was high in epidermal stratum granulosum and mucous glands of the dorsal skin, the bottle-shaped glands and differentiated glands of parotoids, while NPY-IR was rarely seen in the granular glands of ventral skin, and not present in the granular glands of dorsal skin and parotoids. The expression of several types of GI hormones in the skin and parotoids of Bufo gargarizans varies depending on tissue and type of glands.

Evaluation of immunohistochemical expression of ghrelin-producing rectal cells in Wistar rats underwent to the cafeteria diet

To investigate the impact of cafeteria diet on ghrelin expression in rectal tissue and identify the morphologic cell type. Twenty-four male Wistar rats were divided into four subgroups of six animals each: RC1 (rat chow 1) and CAF1 (cafeteria diet 1) for a period of 30 days; RC2 (rat chow 2) and CAF2 (cafeteria diet 2) for a period of 60 days. The animal and rectal weight, the number and the type of immunoreactive ghrelin cells were recorded and compared between the subgroups. The statistical study was established by ANOVA and Student's t test. There was no difference in the total of immunoreactive cells (p=0.685) between the subgroups nor between weight and presence or absence of ghrelin expression (p=0.993). All the immunoreactive cells identified were closed-type. The cafeteria diet did not have influence on the amount of immunoreactive rectal cells of ghrelin and only one type (closed-type) of immunoreactive cells was expressed in the rectum.

Distribution of Gastrin Immune Reactive Cells in the Alimentary Canal of a Stomachless Hill Stream Loach, Lepidocephalus guntea (Hamilton): An Immuno-Histochemical study

The presence of gastrin producing enteroendocrine cells characteristic of so called stomach were also present in stomachless loach Lepidocephalus guntea (Hamilton). The immunohistochemical response reveals their presence in the anterior and middle regions of the intestine. Both open and closed type of cells have been recorded but the former type predominates. Some of the open type of gastrin immune reactive cells, amidst mucosal epithelium have been observed to release their content into the lumen of the intestine, suggesting hormone–parahormone–lumone role of gastrin. The closed type of gastrin immunoreactive cells are mostly located in the sub-mucosal region with characteristic cytoplasmic extensions projecting towards both lumen as well as basal zone of the villi. Keeping their morphological appearance in consideration, the present authors propose that both the types of cells are interconvertible as per their requirement as hormone or parahormone or lumone.

Cardiac telocytes — their junctions and functional implications

Telocytes (TCs) form a cardiac network of interstitial cells. Our previous studies have shown that TCs are involved in heterocellular contacts with cardiomyocytes and cardiac stem/progenitor cells. In addition, TCs frequently establish ‘stromal synapses’ with several types of immunoreactive cells in various organs (www.telocytes.com). Using electron microscopy (EM) and electron microscope tomography (ET), we further investigated the interstitial cell network of TCs and found that TCs form ‘atypical’ junctions with virtually all types of cells in the human heart. EM and ET showed different junction types connecting TCs in a network (puncta adhaerentia minima, processus adhaerentes and manubria adhaerentia). The connections between TCs and cardiomyocytes are ‘dot’ junctions with nanocontacts or asymmetric junctions. Junctions between stem cells and TCs are either ‘stromal synapses’ or adhaerens junctions. An unexpected finding was that TCs have direct cell–cell (nano)contacts with Schwann cells, endothelial cells and pericytes. Therefore, ultrastructural analysis proved that the cardiac TC network could integrate the overall ‘information’ from vascular system (endothelial cells and pericytes), nervous system (Schwann cells), immune system (macrophages, mast cells), interstitium (fibroblasts, extracellular matrix), stem cells/progenitors and working cardiomyocytes. Generally, heterocellular contacts occur by means of minute junctions (point contacts, nanocontacts and planar contacts) and the mean intermembrane distance is within the macromolecular interaction range (10–30 nm). In conclusion, TCs make a network in the myocardial interstitium, which is involved in the long-distance intercellular signaling coordination. This integrated interstitial system appears to be composed of large homotropic zones (TC–TC junctions) and limited (distinct) heterotropic zones (heterocellular junctions of TCs).

Caloric restriction attenuates age-related changes of DNA methyltransferase 3a in mouse hippocampus

Recent studies have suggested that DNA methylation is implicated in age-related changes in gene expression as well as in cognition. DNA methyltransferase 3a (Dnmt3a), which catalyzes DNA methylation, is essential for memory formation and underlying changes in neuronal and synaptic plasticity. Because caloric restriction (CR) and upregulation of antioxidants have been suggested as strategies to attenuate age-related alterations in the brain, we hypothesized that both a diet restricted in calories and transgenic overexpression of normal human Cu/Zn superoxide dismutase 1 (SOD) attenuate age-related changes in Dnmt3a in the aging mouse hippocampus. For this purpose, we performed qualitative and quantitative analyses of Dnmt3a-immunoreactivity (IR) for the hippocampal dentate gyrus (DG), CA3 and CA1-2 regions in 12- and 24-month-old mice from 4 groups, i.e. (1) wild-type (WT) mice on a control diet (WT-CD), (2) SOD-CD mice, (3) WT mice on CR (WT-CR), and (4) SOD–CR. Qualitative analyses revealed two types of Dnmt3a immunoreactive cells: type I cells – present throughout all hippocampal cell layers showing moderate levels of nuclear Dnmt3a-IR, and type II cells – a subpopulation of hippocampal cells showing very intense nuclear Dnmt3a-IR, and colocalization with Bromodeoxyuridine. Quantitative analyses indicated that the age-related increase in Dnmt3a-IR within the CA3 and CA1-2 in type I cells was attenuated by CR, but not by SOD overexpression. In contrast, the density of type II Dnmt3a immunoreactive cells showed an age-related reduction, without significant effects of both CR and SOD. These changes in Dnmt3a levels in the mouse hippocampus may have a significant impact on gene expression and associated cognitive functioning.

Abstract 4959: Multispectral imaging of chromogenic multiplex IHC assays as an alternative to fluorescent methods

Abstract Detection and analysis of two or more co-localized antigens by light microscopy has been hindered by the difficulty in discerning and quantifying overlaying chromogens. Performing multi-analyte immunohistochemistry has many potential benefits and applications in the field of drug target evaluation and patient screening, including: 1) determination and quantification of immunoreactivity co-localization; 2) evaluation of spatial relationships between immunoreactive cell types; 3) signal transduction pathway activation studies; 4) reduction in tissue depletion; and 5) decreased reagent utilization. Multiplex immunofluorescence is not widely used as an analytical technique for clinical samples due to its lower sensitivity than chromogenic methods and concerns about autofluorescence in formalin-fixed tissue. Through the use of multispectral imaging, the absorption pattern of overlapping chromogens can be spectrally unmixed into quantitative individual dye components. This process works accurately when chromogens are developed to a lower intensity than typical for most standard pathology laboratories. The chromogens must be developed to a point where they do not scatter light or block subsequent chromogenic development. The current study was performed to define the accuracy of spectral unmixing of chromogens and evaluate whether interference existed between chromogens. Stained samples were imaged using multispectral imaging, and quantitative grayscale images for each analyte were created by spectral unmixing. The grayscale images were analyzed using image analysis software to determine the overall expression levels of each analyte. Development with Vulcan Red followed by DAB produced little interference, while high density development with DAB decreased the subsequent Vulcan Red staining intensity. Vulcan Red, DAB and hematoxylin unmixed properly and quantitatively. In summary, when multiplexed chromogenic IHC assays were developed using methods optimized for multispectral imaging, the technique demonstrated excellence performance characteristics without suffering from drawbacks commonly associated with fluorescence-based techniques. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4959.

An immunohistochemical study of pancreatic endocrine cells in SKH-1 hairless mice.

The regional distribution and frequency of the pancreatic endocrine cells in the SKH-1 hairless mouse were studied by an immunohistochemical (peroxidase anti-peroxidase; PAP) method using four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). The pancreas of mice were divided into three portions; pancreatic islets, exocrine and pancreatic ducts. The pancreatic islets were further subdivided into three regions (central, mantle and peripheral region) according to their located types of immunoreactive cells. In the pancreatic islet portions, insulin-immunoreactive cells were located in the central and mantle regions with 84.60 +/- 7.65 and 33.00 +/- 12.45/100 cells frequencies, respectively, but most of somatostatin-, glucagon- and PP-immunoreactive cells were detected in the mantle and peripheral regions. In the mantle region, somatostatin-, glucagon- and PP-immunoreactive cells were demonstrated with 28.70 +/- 9.91, 52.00 +/- 14.05 and 2.60 +/- 1.51/100 cells frequencies, respectively, and showed 6.20 +/- 2.86, 15.30 +/- 5.31 and 21.50 +/- 10.28/100 cells frequencies, respectively in peripheral regions. However, glucagon-immunoreactive cells were also demonstrated in the central regions with 4.00 +/- 2.83/100 cells frequency. In the exocrine portions, insulin-, glucagon-, somatostatin- and PP-immunoreactive cells were demonstrated in the SKH-1 mouse with 0.90 +/- 0.74, 0.80 +/- 0.79,4.90 +/- 3.54 and 2.70 +/- 1.34/100 cells frequencies, respectively. In the pancreatic duct portions, insulin-, glucagon- and somatostatin-immunoreactive cells were demonstrated in the subepithelial connective tissues and showed islet-like appearances with 30.30 +/- 14.67, 2.70 +/- 3.13 and 5.90 +/- 4.23/100 cells frequencies, respectively. However, no PP-immunoreactive cells were demonstrated in these regions. In conclusion, some peculiar distributional patterns of pancreatic endocrine cells were found in the SKH-1 hairless mouse.

Abstract C80: Characterizing models for personalized medicine: Endosialin in sarcoma from cultured cells to mice to humans

Abstract A survey of endosialin by IHC was previously conducted in 250 clinical specimens of cancer, revealing a key difference between sarcomas and carcinomas: in sarcomas, endosialin was expressed in tumor cells, stromal fibroblasts and perivascular cells, while in carcinomas tumor cells were negative. Endosialin expression was frequent among sarcoma patients and reached high levels: 70 of 86 sarcomas (81%) were positive for endosialin, with 44 (51%) displaying at least 50% coverage of all 3 immunoreactive cell types as a whole. Staining intensity was scored on the scale 0, 1+, 2+, 3+: all 9 sarcoma subtypes surveyed included specimens reaching 2+ and 3+. Endosialin emerged from that study as a potential molecular target for sarcomas. However, despite frequent expression and high levels observed in patients, some sarcomas are endosialin-negative and some express low levels. Therefore, targeting endosialin would mandate a personalized medicine approach where patients are tested for endosialin expression in order to determine eligibility for endosialin-directed therapy. We characterized the expression of endosialin in human tumor cell lines in vitro and in vivo, from mRNA and protein in cell culture to protein in xenograft tumors. Thirty-seven human sarcoma cell lines and one neuroblastoma cell line were assayed for endosialin by real-time PCR and flow cytometry. Eighteen cell lines were positive for the protein at various levels. There was a positive correlation between transcript and protein expression, with a few exceptions: 3 cell lines expressed very low levels of the transcript yet clearly detectable protein and one cell line expressed detectable transcript yet no protein. Fifteen of the 18 cell lines positive for the protein in vitro were implanted in mice subcutaneously. Eight of the 15 cell lines implanted failed to form tumors. Seven formed tumor nodules that were excised and tested for endosialin by IHC using the same assay as that used for clinical specimens. Protein expression was not always as robust in vivo as the in vitro expression might have suggested. Staining in the xenograft tumors was scored on the same scale as the clinical specimens. Some models showed robust and homogeneous expression throughout the tumor tissue (SK-N-AS neuroblastoma), while others showed highly heterogeneous staining. In one model representing extreme heterogeneity (SJSA-1 osteosarcoma), endosialin was highly regional, with areas staining positive at the 3+ intensity level and adjacent areas being negative. Both homogeneous and heterogeneous staining was seen in human clinical specimens. Our work demonstrates the importance of characterizing disease models to ascertain target expression at all stages of testing from in vitro to mice and to humans, since expression in vivo cannot be assumed from expression in cell culture and expression patterns in mice may or may not be similar to expression patterns in humans. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C80.

Branchial ammonia excretion in the Asian weatherloach Misgurnus anguillicaudatus

The weatherloach, Misgurnus anguillicaudatus, is a freshwater, facultative air-breathing fish that lives in streams and rice paddy fields, where it may experience drought and/or high environmental ammonia (HEA) conditions. The aim of this study was to determine what roles branchial Na +/K +-ATPase, H +-ATPase, and Rhcg have in ammonia tolerance and how the weatherloach copes with ammonia loading conditions. The loach's high ammonia tolerance was confirmed as was evident from its high 96 h LC 50 value and high tissue tolerance to ammonia. The weatherloach does not appear to make use of Na +/NH 4 +-ATPase facilitated transport to excrete ammonia when exposed to HEA or to high environmental pH since no changes in activity were observed. Using immunofluorescence microscopy, distinct populations of vacuolar (V)-type H +-ATPase and Na +/K +-ATPase immunoreactive cells were identified in branchial epithelia, with apical and basolateral staining patterns, respectively. Rhesus C glycoprotein (Rhcg1), an ammonia transport protein, immunoreactivity was also found in a similar pattern as H +-ATPase. Rhcg1 (Slc42a3) mRNA expression also increased significantly during aerial exposure, although not significantly under ammonia loading conditions. The colocalization of H +-ATPase and Rhcg1 to the similar non-Na +/K +-ATPase immunoreactive cell type would support a role for H +-ATPase in ammonia excretion via Rhcg by NH 4 + trapping. The importance of gill boundary layer acidification in net ammonia excretion was confirmed in this fish; however, it was not associated with an increase in H +-ATPase expression, since tissue activity and protein levels did not increase with high environmental pH and/or HEA. However the V-ATPase inhibitor, bafilomycin, did decrease net ammonia flux whereas other ion transport inhibitors (amiloride, SITS) had no effect. H +-ATPase inhibition also resulted in a consequent elevation in plasma ammonia levels and a decrease in the net acid flux. In gill, aerial exposure was also associated with a significant increase in membrane fluidity (or increase in permeability) which would presumably enhance NH 3 permeation through the plasma membrane. Taken together, these results indicate the gill of the weatherloach is responsive to aerial conditions that would aid ammonia excretion.

Immunocytochemical study of gastrintestinal endocrine cells in insectivorous bats (Mammalia: Chiroptera)

The regional distribution and relative frequency of endocrine cells in the stomach and intestine of Phyllostomidae: Lonchorhina aurita and Molossidae: Molossus molossus bats were studied immunohistochemically. Three types of immunoreactive (IR) endocrine cells--to serotonin (5-HT), gastrin (GAS) and enteroglucagon (GLUC)--were found in the gastric mucosa and four types of IR cells were identified in the intestinal mucosa. This study showed an interespecfic difference in the regional distribution and relative frequency of endocrine cells in the Chiropteran alimentary tract.

Shifting of parvalbumin expression in the rat retina in experimentally induced diabetes

The AII amacrine cell, a unique rod signal integrator passing through the cone bipolar cell to ganglion cells, uses parvalbumin as a transducer of cytosolic calcium ion signals in the mammalian retina. For clarification of whether AII amacrine cell network contributes to the early neuropathogenesis of diabetic retinopathy, this study first analyzed alteration of parvalbumin expression in experimental diabetic retinas using immunohistochemical methods. Parvalbumin immunoreactivity was found in AII amacrine cells, some amacrine cells of a wide-field type, and displaced amacrine cells of the normal rat retina. During diabetes, cell density of each parvalbumin immunoreactive amacrine cell type showed no large changes despite decrease in immunoreactivity especially in AII amacrine cells. In addition to these parvalbumin immunoreactive amacrine cell types, a type of cone bipolar cells co-expressing glutamate transporter 1b and connecting electrically with AII amacrine cells appeared clearly by 4 weeks of diabetes, and thereafter sharply increased in number to that of AII amacrine cells. Protein levels of parvalbumin throughout the diabetic retinas also showed no large changes, except a transitional slight increase at 4 weeks of diabetes. These results suggest that the parvalbumin expression propagates from AII amacrine cells to a type of cone bipolar cell through electrical synapses due to dysfunction of biased mechanism in calcium ion buffering, caused by diabetic injury, and thus AII amacrine cells are closely involved in neuropathogenesis of ongoing diabetic retinopathy.

Immunocytochemical study of the distribuition of endocrine cells in the pancreas of the Brazilian sparrow species Zonotrichia Capensis Subtorquata (Swaison, 1837)

In the present study, we investigated types of pancreatic endocrine cells and its respective peptides in the Brazilian sparrow species using immunocytochemistry. The use of polyclonal specific antisera for somatostatin, glucagon, avian pancreatic polypeptide (APP), YY polypeptide (PYY) and insulin, revealed a diversified distribution in the pancreas. All these types of immunoreactive cells were observed in the pancreas with different amounts. Insulin-Immunoreactive cells to (B cells) were most numerous, preferably occupying the central place in the pancreatic islets. Somatostatin, PPA, PYY and glucagon immunoreactive cells occurred in a lower frequency in the periphery of pancreatic islets.

TNF-α and oligodendrocyte apoptosis after cervical spinal cord injury (SCI) (96.11)

Abstract The mechanism of SCI induced oligodendrocyte apoptosis is poorly understood. Tumor necrosis factor alpha (TNF-α) is a pleiotropic cytokine that is involved in inflammatory mediated cell death and thought to play a pivotal role in secondary pathology after SCI, including oligodendrocyte cell death. Utilizing a contusive SCI model in rat, we characterized the spatial, temporal, and cellular profiles of tnf-α expression and production acutely post-injury. Temporally, tnf-α mRNA, as assessed by RT-PCR, increased within 1 h and remained elevated through 24 h, albeit to a much lesser extent. In situ hybridization performed at 1 h revealed tnf-α mRNA throughout a cross-sectional area of the spinal cord. Though the tnf-α mRNA was diffusely distributed in the white matter, it was predominantly expressed in the gray matter. On the other hand, TNF-α protein increased by 1 h post injury and peaked at 4 h as measured by ELISA. At 1 h, 4 h, or 24 h, TNF-α immunoreactivity was present both within and adjacent to the injury epicenter; in the ventral gray matter and throughout the majority of the white matter. Using a cell specific marker (CC1) we found that oligodendrocytes were the principle TNF-α immunoreactive cell type after SCI as analyzed by stereological methods. These oligodendrocytes were also TUNEL positive, suggesting that TNF-α might be cytotoxic to oligodendrocytes acutely following cervical SCI.

Changes in gastric endocrine cells in Balb/c mice bearing CT-26 carcinoma cells: an immunohistochemical study

The distribution and density of gastric endocrine cells in Balb/c mice bearing CT-26 carcinoma cells were studied immunohistochemically employing specific antisera against serotonin, somatostatin, glucagon, gastrin, cholecystokinin (CCK)-8 and human pancreatic polypeptide (hPP). The animals were divided into two groups, a non-implanted sham group and a CT-26 carcinoma cell-implanted group. Samples were collected from two regions of the stomach (fundus and pylorus) at 28 days after implantation of the medium or the CT-26 cells (1x10(5) cells/mouse). Five of the 6 types of immunoreactive (IR) cells were identified, with only the hPP IR cells not being detected. The regional distribution of the gastric endocrine cells in the CT-26 implanted group was similar to that of the non-implanted sham group. However, the endocrine cells were significantly decreased in the CT-26-implanted group as compared to those of the non-implanted sham group. Serotonin- and somatostatin-IR cells in the fundus and pylorus , and gastrin- and CCK-8-IR cells in the pylorus of the CT-26 implanted groups were significantly decreased compared to those of the sham group. In addition, glucagon-IR cells were restricted only to the fundus of the sham animals. hPP-IR cells were not detected in either the T-26 implanted- or the non-implanted group. Since endocrine cells are the anatomical units responsible for the production of gut hormones, a change in their density may reflect a change in their capacity to produce such hormones. Implantation of the tumor cell mass induced severe quantitative changes in gastric endocrine cell density, an abnormality which may contribute to the development of gastrointestinal symptoms, such as anorexia and indigestion, frequently encountered in cancer patients.