Biomedical subjects

J Roth

Publications and source records attributed to J Roth.

At least 253 records · Page 14Linked to original sources

PubMed1994

Substance P and calcitonin gene-related peptide modulate leukocyte infiltration to mouse skin during allergic contact dermatitis.

The effects of the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) on leukocyte infiltration during allergic contact dermatitis (ACD) in mice were studied. Concomitant topical application of SP or CGRP with the allergen oxazolone resulted in enhanced leukocyte recruitment at the sites of challenge. Immunohistochemical studies revealed that the numbers of T-helper (L3T4+) and cytotoxic (Lyt-2) lymphocytes and infiltrating macrophages (BM8+) were increased. In addition, ICAM-1 and MHC class II molecule expression by these cells was enhanced after neuropeptide application. Analysis by confocal laser scanning microscopy revealed an increase in the immunoreactivity for SP and CGRP in nerve fibres during the course of ACD. Flow cytometry studies showed that SP and CGRP did not upregulate expression of the adhesion molecules ICAM-1 and VCAM-1 by murine endothelial cell lines in vitro. This suggests that increased infiltration of leukocytes during ACD is not a consequence of direct neuropeptide-promoted upregulation of endothelial adhesion molecules in vivo. In conclusion, our observations provide evidence for a modulatory role of neuropeptides in the pathogenesis of ACD.

Animals↗

PubMed1994

Identifying the mental health needs of children living in families with AIDS or HIV infection.

The present article highlights the mental health needs of children living with loved ones who have AIDS or HIV infection. In addition the article describes an intervention program which is being developed to meet the needs of the children and their families. Children who live in families affected by AIDS and HIV infection, like children who live with other life-threatening illnesses, are vulnerable to psychological distress. They experience numerous separations from parents, changes in the nature and predictability of emotional nurturing, concerns about loss, disruptions in routine and contact with peers, and economic hardship. AIDS and HIV infection present the additional stressors that stem from discrimination, stereotyping, and social ostracism. Finally, many families living with AIDS or HIV infection are disenfranchised, living under the pall of poverty and substance abuse. The intervention program described is being implemented in an urban community mental health clinic to meet the diverse mental health needs of the children living in these families. Preliminary implications of the program are discussed so as to begin a dialogue with other agencies who are challenged to meet the needs of this heterogeneous population.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Mutational analysis of the first 14 exons of the adenomatous polyposis coli (APC) gene.

In the present study, the polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) technique has been applied to the mutation analysis of the adenomatous polyposis coli (APC) gene. We examined the first 14 exons of the APC gene in 46 polyposis coli patients. Five germline mutations were observed, including a single-nucleotide substitution and small (1-4 bp) deletions leading, in 4 cases, to a stop codon. A missense mutation in exon 3 and a 1 bp deletion in exon 4 of the APC gene were observed in patients presenting with the attenuated form of FAP.

Adenomatous Polyposis Coli↗

PubMed1994

Evaluation of methods for hepatitis C virus detection in archival liver biopsies. Comparison of histology, immunohistochemistry, in-situ hybridization, reverse transcriptase polymerase chain reaction (RT-PCR) and in-situ RT-PCR.

To evaluate reliable methods for detection of hepatitis C virus (HCV) infection in routinely processed liver biopsies we analyzed formaldehyde-fixed and paraffin-embedded liver specimens of 10 patients with serological confirmed HCV infection. We compared (1) conventional histology; (2) indirect immunofluorescence using the mAb TORDJI-22 (Clonatec, Paris, France); (3) RT-PCR using total RNA and Southern blotting with chemiluminescent detection; (4) non-radioactive in-situ hybridization (ISH) with digoxigenin-labeled oligo- and cRNA probes; (5) direct in-situ RT-PCR with incorporation of labeled nucleotides into PCR-products, and (6) indirect in-situ RT-PCR using subsequent ISH for the visualization of intracellular PCR-products. Our results indicate that: (1) using the histological criteria described by Lefkowitch et al. [Gastroenerology 1993;104:595] together with clinical data, most chronic HCV infections can be diagnosed by conventional histology, if liver biopsies specimens are adequate; (2) the commercially available mAb TORDJI-22 appears to crossreact with non-HCV epitopes, resulting in false positives; (3) molecular methods performed on routinely fixed and processed liver biopsies frequently yield false negative results due to sampling problems, low viral copy number and RNA degradation in infected cells; (4) analysis of HCV-RNA by RT-PCR of extracted total RNA is more sensitive than indirect in-situ RT-PCR or ISH; and (5) direct in-situ RT-PCR is not reliable despite the use of modifications such as DNase pretreatment and hot-start procedures. It is concluded, that several molecular methods for HCV detection must await further improvements of protocols to be suitable for routine diagnostics on paraffin-embedded liver biopsies.

Base Sequence↗

PubMed1994

Polysialic acid of the neural cell adhesion molecule (N-CAM) is widely expressed during organogenesis in mesodermal and endodermal derivatives.

We have studied the expression of homopolymers of alpha 2,8-linked sialic acid (polySia) and the neural cell adhesion molecule (N-CAM) during the embryonic and fetal development of rat, chicken and man using immunocytochemistry and immunoblotting. During development, polySia and N-CAM were widely expressed in mesodermally and neuro-ectodermally derived elements. In specific developmental processes, cells of endodermal and ectodermal (non-neural) origin were also immunoreactive for these molecules. Loss of polySia and N-CAM immunoreactivity often accompanied differentiation of mesodermally derived cells. In cartilage formation for instance, cells in precartilaginous mesenchymal condensations stained for N-CAM and polySia until the first appearance of specific chondrocyte function, independent of the stage of development. Transient de novo expression of polySia, in newly induced ectodermal cells, paralleled the reciprocal inductive interactions of mesodermally derived cells with cells of ectodermal origin during hair follicle formation. All ectodermally derived hair follicle cells, except the putative stem cells, later ceased expression of these molecules. Ectodermal expression of polySia and N-CAM was otherwise rare. The endodermally derived epithelium of the digestive and respiratory tracts were polySia and N-CAM immunoreactive early in organogenesis (embryonic day 12 in mouse). Cells of this derivation later all became unreactive, although decrease in immunoreactivity during development was faster in derivatives of more cranial portions of the endoderm. In general, during organogenesis, epithelial elements showed polySia and N-CAM expression before and during epithelium formation, thereafter losing immunoreactivity, irrespective of the developmental origin of the epithelial cells. PolySia and N-CAM staining in the chicken respiratory tract epithelium was more wide-spread and lasted significantly longer than in either man or rat. Cells that expressed N-CAM, but not polySia, were found during the development of both skin and pancreas, indicating independent control of polySia expression. Outside the nervous system no cells that expressed polySia but not N-CAM were observed.

Animals↗

PubMed1994

Suppressors of recB mutations in Salmonella typhimurium.

Using a screen that directly assesses transductional proficiency, we have isolated suppressors of recB mutations in Salmonella typhimurium. The alleles of sbcB reported here are phenotypically distinct from those isolated in Escherichia coli in that they restore recombination proficiency (Rec+), resistance to ultraviolet light (UVR), and mitomycin C resistance (MCR) in the absence of an accompanying sbcCD mutation. In addition the sbcB alleles reported here are co-dominant to sbcB+. We have also isolated insertion and deletion mutants of the sbcB locus. These null mutations suppress only the UVS phenotype of recB mutants. We have also isolated sbcCD mutations, which map near proC. These sbcCD mutations increase the viability, recombination proficiency and MCR of both the transductional recombination suppressors (sbcB1 & sbcB6) and the sbcB null mutations. S. typhimurium recB sbcB1 sbcCD8 strains are 15-fold more recombination proficient than wild-type strains. The increase in transductants in these strains is accompanied by a loss of abortive transductants suggesting that these fragments are accessible to the mutant recombination apparatus. Using tandem duplications, we have constructed sbcB merodiploids and found that, in a recB mutant sbcCD+ genetic background, the sbcB+ allele is dominant to sbcB1 for transductional recombination but co-dominant for UVR and MCR. However, in a recB sbcCD8 genetic background, the sbcB1 mutation is co-dominant to sbcB+ for all phenotypes. Our results lead us to suggest that the SbcB and SbcCD proteins have roles in RecBCD-dependent recombination.

Alleles↗

PubMed1994

Polysialic acid of the neural cell adhesion molecule in the human thyroid: a marker for medullary thyroid carcinoma and primary C-cell hyperplasia. An immunohistochemical study on 79 thyroid lesions.

We recently reported that the gold-labeled monoclonal antibody MAb 735, reactive with a long-chain form of alpha-2,8-linked polysialic acid (polySia) found on the neural cell adhesion molecule (NCAM), is useful to immunohistochemically distinguish small-cell lung carcinomas from neuroendocrine carcinomas with higher grade of differentiation (carcinoids) and other types of lung carcinomas (Am J Pathol 1991;139:297). In this study, we tested the occurrence of polySia in various types of malignant thyroid tumors and C-cell hyperplasia to determine whether polySia is a useful adjunct for the differential diagnosis of medullary thyroid carcinoma (MTC) and other thyroid neoplasms and to distinguish primary from secondary (reactive) C-cell hyperplasia (CCH). We examined formaldehyde-fixed and paraffin-embedded sections of 79 thyroid lesions, consisting of 33 MTC (14 familial and 19 sporadic tumors), 13 follicular, 11 papillary, 16 anaplastic carcinomas, and four glands with primary and two with secondary CCH. We applied a direct and an indirect immunogold-silver technique for polySia, CT, and CEA detection, respectively. All 33 MTC showed a strong cell-surface-associated immunoreactivity for polySia, which was sensitive to endoneuraminidase digestion. The polySia immunoreactivity of nerves served as an internal control in all specimens. Immunoreactivity for CT and CEA was present in all MTC with the exception of one recurrent tumor with features of an anaplastic MTC type. All other thyroid neoplasms were nonreactive for polySia, CT, and CEA. Primary CCH associated with MTC showed a strong polySia immunostaining, which was less intense in primary CCH not combined with MTC. In normal-appearing C cells and in secondary CCH, staining for polySia was absent in the majority of cases. We conclude that polySia of NCAM is a valuable marker to distinguish medullary carcinomas from other types of thyroid carcinomas. Furthermore, it allows for the discrimination of primary from secondary C-cell hyperplasia and may be helpful to better define the normal range of C cells in unaffected members of a family with a history of multiple endocrine neoplasia (MEN)-II.

Adolescent↗

PubMed1994

Differential regulation of the macrophage-specific surface antigen RM3/1 by cyclosporine, azathioprine, and dexamethasone.

CsA, AZA, and dexamethasone (DEX) were examined for their ability to modulate expression of surface antigens on human monocytes. Peripheral blood monocytes were cultured for 1 day, treated with various concentrations of immunosuppressants, and subsequently analyzed for expression of macrophage differentiation antigen RM3/1, intercellular adhesion molecule-1 (CD54), beta 2-integrin (CD18), and HLA-DR using flow cytometry and indirect immunofluorescence microscopy. The RM3/1 antigen was found to be significantly down-regulated by CsA and AZA in a dose-dependent manner, whereas DEX led to a marked up-regulation of the RM3/1 molecule. In contrast, expression of CD54, CD18, and HLA-DR by macrophages was not affected by treatment with these immunosuppressants. Effects of AZA, CsA, and DEX on RM3/1 surface expression were shown to be mediated via modulation of RM3/1 de novo synthesis. Immunohistochemical analysis of rejected renal allografts revealed that the RM3/1 antigen is expressed by the majority of infiltrating macrophages. Our data demonstrate that CsA, AZA, and DEX differentially affect gene expression, resulting in distinct macrophage phenotypes. Characterization of the RM3/1+ macrophage population in vitro and during the course of allograft rejection in vivo may thus provide further insights regarding the mode of immunosuppressant action on nonspecific effector mechanisms.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1994

Apomorphine induced cognitive changes in Parkinson's disease.

Auditory event related potentials (ERPs) and visual evoked potentials (VEPs) were recorded from eight patients with Parkinson's disease, before and after a single dose of apomorphine. To assess the treatment effects, the patients' motor state, Benton visual retention test (BVRT), and digit span tests were also examined. After apomorphine, although motor performance improved, the ERP latencies were delayed and the N2-P3 ERP amplitude was significantly diminished by comparison with pretreatment values. These data suggest that apomorphine induces, besides its motor effects in patients with Parkinson's disease, a slowing down of cognitive processing. Preferential stimulation of dopamine autoreceptors in mesocortical and mesolimbic systems may represent a neural mechanism for these effects. Also, the posttreatment BVRT rotation errors significantly increased, suggesting an apomorphine induced impairment of visuospatial perception.

Apomorphine↗

PubMed1994

Antipyresis caused by stimulation of vasopressinergic neurons and intraseptal or systemic infusions of gamma-MSH.

Antipyretic properties have been ascribed to arginine vasopressin (AVP), and the site where its antipyretic effects are mediated in the brain was identified as the ventrolateral septum of the limbic system. In guinea pigs, the majority of AVP projections to the septum originate from parvocellular neurons of the hypothalamic paraventricular nucleus (PVN). Electrical stimulation of the PVN with 10-s trains of current pulses (duration 1 ms, frequency 20 Hz, amplitude 8 V, current 0.205 +/- 0.017 mA) reduced the febrile response to an intramuscular injection of 20 micrograms/kg lipopolysaccharide (LPS from Escherichia coli, 0111: B4) by 54% compared with unstimulated animals. This reduction in fever by electrical PVN stimulation was partly reversed by a simultaneous intraseptal microinfusion of the vasopressinergic V1-receptor antagonist d(CH2)5[Tyr(Met)2]AVP at a concentration of 10(-5) mol for 6 h with an infusion speed of 0.1 microliter/min. We further investigated the effects of intraseptal microinfusions or systemic infusions of the gamma-melanocyte-stimulating hormone (gamma-MSH), a derivative of the proopiomelanocortin, on LPS-induced fever. Intraseptal microinfusions of gamma-MSH at a concentration of 10(-5) mol/l for 6 h with an infusion speed of 0.1 microliter/min caused a 38% reduction in fever. A significantly greater 57% reduction in fever was observed when the intraseptal microinfusion of gamma-MSH was combined with electrical stimulation of the PVN (for parameters see above). A systemic infusion of 0.261 mumol gamma-MSH for 6 h reduced LPS fever to approximately 50% compared with animals infused with vehicle (0.9% saline).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Incretin hormones regulate glucose-dependent insulin secretion in RIN 1046-38 cells: mechanisms of action.

Glucagon-like peptide-1-(7-36) amide (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are known incretin hormones, released from enteroendocrine cells in response to food, that enhance insulin secretion, but only in the presence of elevated blood glucose. We used a rat insulinoma cell line, RIN 1046-38, to study the mechanisms underlying the interaction of incretins and glucose. We measured insulin secretion using RIA and the reverse hemolytic plaque assay. GLP-1 stimulates insulin secretion, with a half-maximal concentration of 34 pM. GLP-1 is approximately 2 orders of magnitude more potent than GIP. GLP-1 and GIP have additive effects at submaximal concentrations, but probably not at maximal concentrations, suggesting a common signal transduction pathway. The glucose requirement for GLP-1 action can be replaced by cell membrane depolarization (20 mM KCl in the extracellular medium), suggesting that a rise of intracellular Ca2+ may be an early step required for GLP-1 action. GLP-1 stimulates insulin secretion by significantly increasing the maximum rate of insulin secretion from 10.3 +/- 2.25 to 25.2 +/- 2.94 ng insulin/mg protein.h. GLP-1 acts by recruiting 1.5-fold more cells to secrete insulin as well as enhancing insulin secretion by individual cells. Combinations of stimuli, such as glucose, cell membrane depolarization, and GLP-1, can recruit 90% of RIN 1046-38 cells to secrete insulin.

Animals↗

PubMed1994

Glucagon-like peptide-1(7-36) amide (GLP-1) enhances insulin-stimulated glucose metabolism in 3T3-L1 adipocytes: one of several potential extrapancreatic sites of GLP-1 action.

We investigated the effects of glucagon-like peptide-1(7-36) amide, GLP-1, on glucose metabolism in 3T3-L1 adipocytes and we used polymerase chain reaction to search for the presence of GLP-1 receptors in various rat tissues. GLP-1 at 1 nM significantly increased insulin-mediated 2-deoxyglucose uptake by 40% while having no effect on basal uptake. In conjunction with the elevated uptake, the insulin-dependent incorporation of 14C-glucose into fatty acids was also increased. Moreover, neither glycogen synthesis nor insulin binding to its receptor were affected by GLP-1. In addition to the presence of GLP-1 receptor in pancreas we found messenger RNA for this receptor in brain, kidney, heart, fat, skeletal muscle, liver, and intestine. This study indicates that GLP-1, in addition to its well known effect of stimulating insulin secretion, may improve insulin responsiveness by promoting fatty acid synthesis in adipose cells and possibly modulating insulin signaling in other insulin sensitive tissues.

3T3 Cells↗

PubMed1994

Xenopus laevis oocytes, eggs and tadpoles contain immunoactive insulin.

Insulin is a multifunctional polypeptide hormone that regulates metabolic processes and promotes mitogenesis and differentiation in vitro in the cells and tissues of several species. Its role in vivo during embryogenesis is still poorly understood. We have previously found insulin mRNA in mature Xenopus laevis oocytes and in embryos during neurulation (before organogenesis of the pancreas takes place). We have now measured insulin immunoactivity in mature oocytes, unfertilized eggs and day-2 tadpoles. Using reversed phase high performance liquid chromatography, we found low levels of insulin in extracts of oocytes (stage VI). Both Xenopus insulin I and II were detected in unfertilized eggs. The day-2 tadpoles (stages 31-33) also contained immunoactive insulin, and in swimming tadpoles (stage 46) a few clusters of cells containing insulin immunoactivity could be identified by indirect immunofluorescence. Immunoblot analysis was relatively insensitive, detecting insulin only in the adult Xenopus pancreas. In summary, insulin (from maternal origin and embryonic expression) appears to be present early enough in Xenopus laevis to influence developmental processes such as neurulation.

Animals↗

PubMed1994

Detection of Epstein-Barr virus DNA in Hodgkin- and Reed-Sternberg-cells by single cell PCR.

The Epstein-Barr virus (EBV) can be detected in the majority of lymph nodes involved by Hodgkin's lymphoma using the highly sensitive polymerase chain reaction (PCR). However, the rate of EBV-DNA detection by in-situ hybridisation, which allows allocation of EBV to a defined cell population, i.e. the neoplastic H&RS-cells, is lower. In an attempt to combine the advantages of the high sensitivity of the PCR and the possibility of cellular allocation by in-situ hybridisation, we established a single-cell PCR of Hodgkin- and Reed-Sternberg (H&RS)-cells isolated by micromanipulation from biopsy tissues. We amplified EBV sequences from the BamW-region by single-cell PCR. Using this method we were able to detect EBV-DNA in the H&RS-cells from 4 of 6 patients. In EBV positive cases all H&RS-cells of a given patient were positive, proving the high sensitivity and reproducibility of the method. Other cells in the biopsy tissue involved by EBV-positive H&RS-cells were shown to be negative. This indicates that EBV may have a role in the pathogenesis of many but not all cases of Hodgkin's disease.

Adolescent↗

PubMed1994

Cytochemical staining for beta 1,6 branching of asparagine-linked oligosaccharides in variants of metastatic human colon carcinoma cells.

A positive correlation between tumor progression in human colon and increased beta 1,6 branching in oligosaccharides has recently been demonstrated. The present study was undertaken to elucidate whether such a correlation can be extended to variants of metastasizing human colon carcinoma HCT116 cells. The Phaseolus vulgaris leukoagglutinating lectin, which binds to beta 1,6 branched oligosaccharides, was employed. In blots, a band of approximately 140 kd was detectable in both the HCT116a and HCT116b sublines. However, in the more aggressive subline HCT116a, the intensity of this band was increased by 100%, and additional reactive bands of approximately 100 kd and approximately 170 kd were observed. Analysis by electron microscopy revealed lectin labeling in the Golgi apparatus, lysosomal elements, mucus droplets, cytoplasmic vesicles, and at the plasma membrane. Quantification of the lectin plasma membrane labeling revealed a significantly higher labeling intensity in HCT116a cells than in HCT116b cells. The difference in lectin plasma membrane labeling intensity could also be observed in paraffin sections. Thus, variants of metastatic HCT116 colon carcinoma cells differ quantitatively and qualitatively in glycoproteins carrying beta 1,6 branches.

Asparagine↗

PubMed1994

[Pronounced flush symptoms in carcinoid syndrome without liver metastases].

The case of a 78 years old patient with impressive flush symptoms is reported. 5-Hydroxyindoleacetic acid and serotonin were elevated. The responsible pathomorphological structure is a 8 x 4.5 x 6 cm ileocaecal neoplasm. Pre-, intra- and postoperatively liver metastases could not be detected during a 18 month period. After surgery of the carcinoid flush disappeared, so that the tumour seize resulting in enormous secretion of metabolites with endocrine activity should be claimed responsible for causing this symptom.

Aged↗

PubMed1994

[Tumors--disorders of cell adhesion].

Cell adhesion molecules are of pivotal importance during organogenesis and fulfil important functions in maintaining normal organ architecture in the adult. Furthermore, they are involved in diverse and specialized functions such as migration and activation of leukocytes in immunosurveillance and inflammation, and homophilic as well as heterophilic interactions of cells with others and the extracellular matrix. In tumors, various cell adhesion molecules play a role in the complex process of tumor dissemination including metastatic spread. In addition, immunohistochemical detection of certain cell adhesion molecules in tumors has been shown to be of value in predicting the clinical course of the tumor disease. This short review focuses on the polysialic acid of the neural cell adhesion molecule NCAM, integrins and CD44.

Animals↗

PubMed1994

[Comparison of histology, immunohistochemistry, RT-PCR, in situ hybridization, and in situ RT-PCR for demonstration of hepatitis C virus in paraffin-embedded liver biopsies].

To compare immunohistochemical and molecular methods for the detection of hepatitis C virus (HCV) infection in archival liver biopsies we analyzed formalin-fixed and paraffin-embedded liver specimens of 10 patients with serologically confirmed HCV infection. Methods employed included indirect FITC-immunofluorescence, reverse-transcriptase polymerase chain reaction (RT-PCR) using extracted RNA and Southern blotting with chemiluminescence-based detection, non-radioactive in situ hybridization (ISH) with digoxigenin-labeled oligo- and cRNA probes, direct in situ RT-PCR with incorporation of labeled nucleotides into PCR-products, and indirect in situ RT-PCR using subsequent ISH for the visualization of intracellular PCR-products. Our results indicate that: (1) using the histological criteria described by Lefkowitch et al. (Gastroenterology 1993; 104-595) together with clinical data, most chronic HCV infections can be diagnosed by conventional histology, if liver biopsies are representative; (2) the commercially available mAB TORDJI-22 appears to cross-react with non-HCV epitopes; (3) molecular methods performed on routinely fixed and processed liver biopsies frequently yield false negative results due to sampling problems, low viral copy number and RNA degradation in infected cells; (4) analysis of HCV-RNA by RT-PCR of extracted total RNA is more sensitive than indirect in situ RT-PCR or ISH; and (5) direct in situ RT-PCR is not reliable despite the use of modifications such as DNase pretreatment and hot-start procedures. Further studies are required to define both optimal methods for sample processing and improvements of protocols, in order to increase detection sensitivity and specificity of HCV infection by immunohistochemical and molecular methods.

Biopsy↗