Background. In atopic asthma, activated T helper lymphocytes are present in bronchial-biopsy specimens and bronchoalveolar-lavage (BAL) fluid, and their production of cytokines may be important in the pathogenesis of this disorder. Different patterns of cytokine release are characteristic of certain subgroups of T helper cells, termed TH1 and TH2, the former mediating delayed-type hypersensitivity and the latter mediating IgE synthesis and eosinophilia. The pattern of cytokine production in atopic asthma is unknown. Methods. We assessed cells obtained by BAL in subjects with mild atopic asthma and in normal control subjects for the expression of messenger RNA (mRNA) for interleukin-2, 3, 4, and 5, granulocytemacrophage colony-stimulating factor (GM-CSF), and interferon gamma by in situ hybridization with 32P-labeled complementary RNA. Localization of mRNA to BAL T cells was assessed by simultaneous in situ hybridization and immunofluorescence and by in situ hybridization after immunomagnetic enrichment or...

Predominant TH2-like bronchoalveolar T-lymphocyte population in atopic asthma

/pdf/pathology-and-genetics-of-tumours-of-the-digestive-system-3xy9cwrc3c.pdf

Pathology and genetics of tumours of the digestive system

The tachykinin peptide family certainly represents one of the largest peptide families described in the animal organism. So far, more than 40 tachykinins have been isolated from invertebrate (insects, worms, and molluscs), protochordate, and vertebrate (skin, gastrointestinal tract, peripheral and central nervous system) tissues. Substance P (SP), first identified by bioassay as early as 1931 but sequenced only in 1971, several years after the elucidation of the structure of eledoisin from molluscan tissues and of physalaemin from amphibian skin, may be considered as a prototype of the tachykinins. Hitherto, as many as 19 tachykinins have been isolated from amphibian integument, and eight additional peptides have been isolated from amphibian gut and brain. Counterparts of skin tachykinins in mammalian tissues are SP, neurokinin A, and neurokinin B. Three main receptor subtypes for the tachykinins have been identified (NK1, NK2, and NK3), but their number is probably destined to increase. It is obvious that the peripheral and central effects of the tachykinins may substantially vary depending on the activation of different receptor subtypes. Matters are further complicated by the frequent capacity of the single tachykinins to bind, although with different affinity, to more receptors. It has been recognized that tachykinins have a variety of effects in physiological and pathological conditions, and there is evidence suggesting intrinsic neuroprotective and neurodegenerative properties of these neuropeptides. This review provides an update on the current body of knowledge regarding tachykinin occurrence and distribution in the animal kingdom, from the lowest invertebrates to man, and the physiological and pharmacological actions of tachykinins outlining the pregnant importance of this large peptide family.

The Tachykinin Peptide Family

Pathology and genetics: Tumours of the digestive system

The tachykinins, exemplified by substance P, are one of the most intensively studied neuropeptide families. They comprise a series of structurally related peptides that derive from alternate processing of three Tac genes and are expressed throughout the nervous and immune systems. Tachykinins interact with three neurokinin G protein-coupled receptors. The signaling, trafficking, and regulation of neurokinin receptors have also been topics of intense study. Tachykinins participate in important physiological processes in the nervous, immune, gastrointestinal, respiratory, urogenital, and dermal systems, including inflammation, nociception, smooth muscle contractility, epithelial secretion, and proliferation. They contribute to multiple diseases processes, including acute and chronic inflammation and pain, fibrosis, affective and addictive disorders, functional disorders of the intestine and urinary bladder, infection, and cancer. Neurokinin receptor antagonists are selective, potent, and show efficacy in models of disease. In clinical trials there is a singular success: neurokinin 1 receptor antagonists to treat nausea and vomiting. New information about the involvement of tachykinins in infection, fibrosis, and pruritus justifies further trials. A deeper understanding of disease mechanisms is required for the development of more predictive experimental models, and for the design and interpretation of clinical trials. Knowledge of neurokinin receptor structure, and the development of targeting strategies to disrupt disease-relevant subcellular signaling of neurokinin receptors, may refine the next generation of neurokinin receptor antagonists.

/pdf/tachykinins-and-their-receptors-contributions-to-9p131ef91l.pdf

Tachykinins and Their Receptors: Contributions to Physiological Control and the Mechanisms of Disease

Estudios con immunofluorescencia realizados en al tracto gastro-intestinal de las aves (pollo y codornix) han demonstrado el origen celular y la distribucion de cuatro hormonas polipeptidicas: Gastrina, Secretina, Enteroglucagon y VIP. Las cuatro hormonas estan presentes en celulas argirofilas y no en las celulas argentafines (celulas enterocromafines).

Immunohistochemical and ultrastructural studies on the endocrine polypeptide (APUD) cells of the avian gastrointestinal tract

Several studies have shown the use of non-radioactive labelled DNA probes for in situ hybridisation, mainly to identify cellular DNA. In this study mRNA in situ hybridisation was performed on rat pituitary with biotinylated complementary (c) RNA probes for rat prolactin and growth hormone (GH), and compared with radioactive 35S-radiolabelled probes. Biotinylated cRNA probes were labelled with either biotin-11-UTP or with allylamine-UTP, the latter method being able to produce a higher yield of labelled RNA. Different detection systems were tested, and hybridisation signal was seen in cells of anterior pituitary with both types of biotinylated probes. The signals were detected using either avidin-biotin-complex with peroxidase (ABC), peroxidase-anti-peroxidase (PAP) or gold-silver methods. ABC peroxidase detected using glucose oxidase-diaminobenzidine (DAB)-nickel solution appeared to be the best method for detecting labelled RNA probes, with very strong signal and low background. The biotinylated probes were comparable in sensitivity to the radiolabelled probes in detecting prolactin and GH mRNAs in the anterior lobe of the rat pituitary. These results indicate an alternative methods of labelling and detection of biotinylated probes which could have a potential role in research and diagnostic techniques.

Non-isotopic RNA probes. Comparison between different labels and detection systems.

Mid-gut carcinoid tumors have been shown to produce substance P, a tachykinin. A recent addition to this family of peptides is neurokinin A which is cleaved from the same precursor as substance P; beta-pre-pro-tachykinin. The authors have examined mid-gut and pulmonary carcinoid tumors for the presence of the two tachykinins, using immunocytochemical study and radioimmunoassay, and have applied the techniques of in situ hybridization and Northern blot analysis to investigate the expression of mRNA for beta-pre-pro-tachykinin. All gut tumors (n = 8) and three of the six lung tumors examined were found by immunocytochemical study to contain both tachykinins or neurokinin A alone. Chromatographic analysis of tumor extracts suggests that this peptide is being detected as a separate molecule and/or as the C-terminal portion of a larger, uncleaved form. Three of the cases positive for tachykinins showed no detectable serotonin immunoreactivity. Strong hybridization signals for beta-pre-pro-tachykinin mRNA were seen in all but one of the cases studied which contained tachykinin immunoreactivity. Intact mRNA and positive hybridization was found by Northern blot analysis in two mid-gut tumors. Concentrations of tachykinins were found by radioimmunoassay to be higher in mid-gut tumors (substance P 27.2 +/- 19.7 pmol/g; neurokinin A 31.8 +/- 24.2 pmol/g; mean +/- SEM, n = 5) than in lung cases (substance P mean 0.8, range 0.5-1.0 pmol/g; neurokinin A mean 11.0, range 10.0-12.0 pmol/g; n = 3). These results show that mid-gut and pulmonary carcinoid tumors produce tachykinins, which are detected, in some cases, where no serotonin immunoreactivity can be found, possibly because of a high rate of amine secretion. Screening for tachykinins may prove to be a useful diagnostic adjunct for these tumors.

Expression of tachykinins by ileal and lung carcinoid tumors assessed by combined in situ hybridization, immunocytochemistry, and radioimmunoassay

http://rd.springer.com/content/pdf/10.1007%2FBF00315974.pdf

Comparison between different labels and detection systems

The malignant transformation of congenital nevocellular nevi, both large and small, is controversial and presents problems in management. The size of the lesion is taken to indicate potential malignant transformation, but this is an arbitrary scale. A more reliable biological indicator is needed to help predict the lesions at risk. Following the localization of neuron-specific enolase to most cells of the diffuse neuroendocrine system and their neoplasms (including benign and malignant melanocytic lesions), it has been suggested that its level is related to tumor activity. In a prospective trial, the presence of neuron-specific enolase immunoreactivity, its concentration, and gene expression in nevus cells were studied in 31 congenital melanocytic nevi of various sizes (1.5 cm to bathing trunk) using immunocytochemistry, biochemical assay, and in situ hybridization. Twenty-five of the 31 congenital nevi were immunoreactive to neuron-specific enolase antiserum, with stronger immunostaining in the larger lesions. There is an apparent linear relationship between the size of the nevi and the level of neuron-specific enolase (expressed as nanograms per milligram protein). Neuron-specific enolase mRNA was highly expresed in most of large congenital nevi (>15 cm in diameter), as revealed by autoradiography following in situ hybridization. Our results show that neuron-specific enolase and its mRNA are expressed to a greater extent in large congenital nevi compared with smaller lesions. This might prove to be a useful indicator of those lesions at risk of malignant transformation.

Neuron-specific enolase and its mRNA are highly expressed in large congenital nevi: a study using immunocytochemistry, biochemical assay, and in situ hybridization.

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