bluuebunny/crossref_metadata_2025 huggingface dataset:
Pigeon Fanciers' Lung: The Mucin Antigen Is Present in Pigeon Droppings and Pigeon Bloom
Authors: Baldwin Christopher I. , Stevens Beverley , Connors Samantha , Todd Anthony , Bourke Stephen J. , Calvert Jane E. , Allen Adrian
Published: April 2003

Background: Pigeon intestinal mucin has been implicated as an important antigen pigeon fanciers' lung. This study investigated whether mucin is detectable in pigeon droppings and bloom, the likely antigenic sources in disease. Methods: Soluble extracts of a number of materials found in a pigeon loft were prepared and specific IgG subclass antibodies to these antigens were measured in 14 antibody–positive pigeon fanciers. Cross–reactivity between these materials and purified pigeon intestinal mucin was investigated by inhibition of anti–mucin ELISA. Mucin was purified from the soluble extracts of these crude antigen mixtures by CsCl density gradient centrifugation. Results: The patterns of IgG subclass responses to purified pigeon intestinal mucin and to the four materials collected from the pigeon loft were similar. Subclass differences between symptomatic and asymptomatic individuals, demonstrable against purified mucin, were similarly seen against pigeon droppings and pigeon bloom. Both pigeon droppings and pigeon bloom were capable of inhibiting IgG binding to purified pigeon mucin, and mucin inhibited substantially the binding of IgG to these materials. Glycoprotein with a density similar to that described for pigeon intestinal mucin was purified from each source. Conclusion: Pigeon intestinal mucin is present in a variety of materials found in the environment of the pigeon loft in a form capable of reacting with anti–mucin antibodies in the sera of exposed individuals. Reduction in exposure to these materials may decrease the likelihood of developing pigeon fanciers' lung and minimise reactions in sensitised individuals.
Atypical CD3+ CD4low Cell Population in a Boy with Fatal EBV–Infection
Authors: Gruber Rudolf , Krauss-Etschmann Susanne , Jäger Gundula , Belohradsky Bernd H. , Koletzko Sibylle
Published: April 2003

A previously healthy 10–year–old Greek boy born to nonconsanguineous healthy parents developed progressive liver disease after acute infectious mononucleosis. EBV–induced autoimmune hepatitis was suspected and treatment was started with high–dose prednisolone, acyclovir and intravenous immunoglobulins. Despite therapy, his liver function continuously deteriorated and the child died 9 months later in profound immune deficiency from candida septicemia. Flow cytometric analysis of his lymphocytes revealed a major subpopulation of atypical cells (20.3%) which were CD3+, fitted into the lymphocyte gate but showed a very low level of CD4 expression, comparable to that of monocytes. After short–time cell culture, the cells became adherent and developed granules and dendrites. We conclude that these cells may represent strongly activated CD4+ T lymphocytes with downregulated CD4 expression or a subtype of dendritic cells.
Regulation of Allergic Inflammation by Skin–Homing T Cells in Allergic Eczema
Authors: Akdis Cezmi A. , Akdis Mübeccel , Simon Hans-Uwe , Blaser Kurt
Published: April 2003

Background: In allergic inflammations of the skin, the pivotal role of CD45RO+ (memory/effector) T cells expressing the cutaneous lymphocyte–associated antigen (CLA) was demonstrated. In both atopic dermatitis (AD) and contact dermatitis (CD), T cells specific to skin–related allergens were confined to the CLA+ T cell population. Our research was aimed to further characterize these T cells in AD. Methods: CD4+ and CD8+ subsets of CLA+ CD45RO+ T cells were purified from peripheral blood of AD patients and healthy control individuals. We studied, in vivo activation patterns, cytokine profiles, immunoglobulin isotype regulation and the influence of these cells on eosinophil survival and apoptosis. Results: The CLA+ CD45RO+ T cells represent an in– vivo–activated memory/effector T cell subset as shown by surface expression of activation markers, spontaneous proliferation and a lower activation threshold via TCR/CD3 triggering. These cells contain and spontaneously release high amounts of preformed IL–5 and IL–13 but only very little IL–4 and IFN–γ in their cytoplasm, as demonstrated by intracellular cytokine staining immediately after purification. Moreover, CLA+ memory/ effector T cells induce IgE production in B cells and enhance eosinophil survival by inhibiting eosinophil apoptosis in AD. In comparison, the CLA– population represents a resting memory T cell fraction, induces rather IgG4 in B cells and does not show any effect on eosinophil survival and apoptosis. Conclusion: Our results indicate that in–vivo–activated both CD4+ and CD8+ memory/effector T cells with skin–homing property play a specific and decisive role in the pathogenesis and exacerbation of AD. In contrast, resting memory T cells of atopic individuals retain normal, nonallergic immune functions.
Cloning of the Human Homolog of Mouse Transmembrane Tryptase
Authors: Wong Guang W. , Tang Yinzi , Stevens Richard L.
Published: April 2003

Background: Three functionally distinct tryptases have been identified in the mouse, one of which encodes an unusual protease that possesses a membrane–spanning domain located in its C terminus. Methods and Results: Using the deduced nucleotide sequence of this mouse transmembrane tryptase (mTMT) gene in a polymerase chain reaction approach, cDNAs were isolated from a number of tissues which encode its human homolog. The amino acid sequences of hTMT and mTMT are 74% identical, and the human tryptase also has the novel membrane–spanning domain. Conclusion: The discovery that the human genome contains a large number of homologous, but distinct, tryptase genes suggests that the individual members of this family of proteases evolved to carry out discrete functions in mast cell–mediated allergic reactions.
Immunological Mechanisms Operative in Allergen–Specific Immunotherapy
Authors: Ebner Christof
Published: April 2003

Specific immunotherapy (SIT) is the practice of administering increasing doses of allergen extracts to selected subjects suffering from IgE–mediated hypersensitivity, with the ultimate aim of ameliorating the symptoms associated with exposure to the causative allergen. The process is often called hyposensitization or desensitization because one consequence of the treatment is a reduction in sensitivity of the target organ after challenge with the relevant allergen. SIT has been practiced as treatment of type I allergy caused by inhalant allergens and Hymenoptera venoms for more than 80 years on an empirical basis. Today, numerous double–blind, placebo–controlled studies prove the therapeutic effect of SIT. However, the immunological mechanisms underlying successful specific immunotherapy have still not been completely elucidated. This review focuses on recent attempts to characterize the immunological events associated with SIT.
T Cell Receptor Vβ Repertoire in Bronchoalveolar Lavage in Wegener’s Granulomatosis and Sarcoidosis
Authors: Schnabel A. , Renz H. , Petermann R. , Csernok E. , Gross W.L.
Published: April 2003

Background: Lymphocytic alveolitis is a common feature of Wegener’s granulomatosis (WG) and sarcoidosis. In pulmonary sarcoidosis analysis of the T cell receptor (TCR) configuration disclosed a biased TCR repertoire in cells obtained by bronchoalveolar lavage (BAL), suggesting that the pulmonary T cell population contains an oligoclonal, probably antigenically selected component. We examined whether this is also a feature of WG. Methods: The distribution of 16 TCR Vβ phenotypes on BAL cells was compared with the distribution on autologous blood cells in 8 WG patients with lymphocytic alveolitis. A control group was composed of 5 patients with active pulmonary sarcoidosis. The two groups were comparable with respect to the lymphocyte count in BAL and the distribution of the CD4+ and CD8+ T cell subsets in BAL and the blood. Overutilization of individual Vβ phenotypes on BAL cells was considered to be significant when the percentage of positive cells in BAL doubled than in the blood and the frequency in BAL was at least 10% of total BAL T cells. Results: All 5 sarcoidosis patients showed substantial overutilization of individual Vβ families in BAL as compared with the blood. By contrast, only 2 of the 8 WG patients showed overutilization of individual Vβ phenotypes in BAL. Conclusions: These findings do not suggest that the T cell population in BAL of WG patients contains a prominent oligoclonal component. While BAL is a convenient approach to obtain T cells from a site of active disease, BAL cells do not appear to be good material for the isolation of clonally selected T cells in WG.
Molecular Breeding of Allergy Vaccines and Antiallergic Cytokines
Authors: Punnonen Juha
Published: April 2003

Molecular breeding, also called DNA shuffling, is a technology that enables the generation of large libraries of novel genes and vectors, from which improved variants can be selected based on functional properties. In a common format, it involves recursive recombination and mutation, performed by random fragmentation of related DNA sequences, followed by reassembly of the fragments in a self-priming polymerase chain reaction. As in natural evolution, the technique takes advantage of crossovers, deletions, insertions, inversions and point mutations of genes to generate large pools of related sequences. Molecular breeding can be used to generate improved variants of proteins used as therapeutics, such as vaccine antigens, growth factors and immunomodulatory molecules. Moreover, the technology can be applied to evolve entire viruses or vectors, including DNA vaccines. Cytokines downregulating allergic immune responses and allergens are attractive targets for evolution by molecular breeding. This review describes approaches to generate chimeric allergens with T cell epitopes from multiple allergen homologues, while reducing the recognition by preexisting IgE. In addition, the results and applications of molecular breeding in the evolution of improved antiallergic cytokines are discussed.
The Th2 Cytokine Environment of the Placenta
Authors: Dealtry Gillian B. , O’Farrell Minnie K. , Fernandez Nelson
Published: April 2003

It is now accepted that local changes to the balance of Th1/Th2-type cytokines occur during pregnancy within the maternal uterus and fetoplacental unit. These changes in cytokine profiles contribute to implantation of the embryo, development of the placenta, and survival of the fetus to term. Overall within the placenta there is a bias in the ratio of Th1:Th2 cytokines towards the Th2-type cytokines. However, there are specific fluctuations in this balance at implantation and during the initiation of parturition. The predominant cytokines at each stage of gestation function both to limit maternal immune rejection of the semi-allogeneic embryo/fetus, especially at the maternofetal interface; and to facilitate the on-going physiological processes within the maternal reproductive tract. These two, at times conflicting, roles are discussed in this review, with key evidence concerning cytokine expression and function from mouse and humans.
Differential Expression of αv Integrins in K1735 Melanoma Cells
Authors: Li Xiaowu , Chen Bing , Blystone Scott D. , McHugh Kevin P. , Ross F. Patrick , Ramos Daniel M.
Published: April 2003

Tumor cell adherence to and migration on the extracellular matrix is an important aspect of cancer progression. This interaction with the extracellular matrix is mediated primarily through the integrin class of cell adhesion molecules. We identified a restricted expression of αvβ3 in highly metastatic K1735M2 and of αvβ5 in poorly metastatic K1735C23 murine melanoma cells. The highly metastatic cells were ten times more motile on vitronectin and fibronectin and approximately three times more invasive through a reconstituted basement membrane than the poorly metastatic cells. This motility was inhibited by addition of anti-β3 antibodies. Injection of the αvβ3-negative K1735C23 cells into syngeneic mice resulted in the generation of a metastatic variant (K1735C23PM) that neo expressed the αvβ3 complex, indicating that expression of αvβ3 is required for K1735 melanoma metastasis. Injection of highly metastatic K1735M2 cells in the presence of blocking antibody to β3 reduced tumor size by approximately 80%. Treatment of the K1735M2 cells with a retroviral antisense β3 construct significantly reduced their expression of αvβ3 and also reduced their motility on extracellular matrix ligands and their invasion through a reconstituted basement membrane. In contrast, when the K1735C23 cells were treated with a construct containing the full-length β3 cDNA, their motility on extracellular matrix proteins and invasion of a reconstituted basement membrane were significantly increased. These results indicate that αvβ3 is required for migration and invasion of K1735 melanoma cells in vitro and primary tumor growth and metastasis in vivo.
Stimulation of Motility of Human Renal Cell Carcinoma by SPARC/Osteonectin/BM-40 Associated with Type IV Collagen
Authors: Kato Yasumasa , Sakai Naoki , Baba Masaya , Kaneko Shigeki , Kondo Keiichi , Kubota Yoshinobu , Yao Masahiro , Shuin Taro , Saito Shigeru , Koshika Shinri , Kawase Toshio , Miyagi Yohei , Aoki Ichiro , Nagashima Yoji
Published: April 2003

SPARC is known to be important in development and tissue remodelling. Here, we examined the effects of SPARC (secreted protein, acidic and rich in cysteine; osteonectin) derived from a rat osteosarcoma cell line on migration of renal cell carcinoma (RCC) by a Boyden chamber assay. YCR RCC cells migrated through type IV collagen-coated filters without stimuli (basal level). SPARC in the lower compartment stimulated chemotactic activity to 120% of the basal level, whereas premixing of YCR with purified SPARC before inoculation reduced their migration to 72% of the basal level. Furthermore, SPARC mixed with type IV collagen more efficiently stimulated their migration in a concentration-dependent manner (up to 170% of the basal level). This suggests that SPARC bound to type IV collagen plays a role in tumor invasion.
Distribution of Non-Diploid Flow-Cytometric DNA Indices and Their Relation to the Nodal Metastasis in Squamous Cell Carcinomas of the Head and Neck
Authors: Wennerberg Johan , Baldetorp Bo , Wahlberg Peter
Published: April 2003

Squamous cell carcinomas of the head and neck (HNSCC) evolve from diploid epithelial cells of the mucosa. At the time of diagnosis about two thirds of clinically diagnosed HNSCC are non-diploid according to flow-cytometric (FCM) analysis, indicating that during tumour progression there must be an acquisition and accumulation of chromosomal aberrations. At diagnosis one third to one half of HNSCC have clinically positive neck nodes. The objective of the present study was to see whether the progression to a metastatic phenotype is reflected in the distribution of FCM DNA ploidy in node-negative and node-positive HNSCC. The series comprised 200 patients with HNSCC. Tumour samples were obtained from diagnostic biopsies or primary surgery. A multistep preparation method and propidium iodide staining of nuclear DNA content was used for FCM. One hundred and forty one (71%) of the tumours were non-diploid. Only two tumours were hypodiploid (DNA index 0.73 and 0.93, respectively). Ten of the tumours exhibited two non-diploid stem cell lines. The frequency of non-diploidy in node-negative tumours was 65% and in node-positive ones about 80%. The frequency distribution of non-diploid DNA indices clustered in the hypotetraploid region (with a modal value of 1.71–1.74) and did not differ between node-negative and node-positive tumours. The hypothesis that the disposition to metastasis is reflected in the frequency distribution of non-diploid DNA indices could thus not be verified.
c-K-ras Overexpression Is Characteristic for Metastases Derived from a Methylcholanthrene-Induced Fibrosarcoma
Authors: Algarra Ignacio , Perez Matias , Serrano M. José , Garrido Federico , Gaforio José Juan
Published: April 2003

We investigated the relationship between the activation of the c-myc and c-K-ras proto-oncogenes and the acquisition of metastatic potential in a methylcholanthrene-induced BALB/c fibrosarcoma. The murine fibrosarcoma GR9 was originally induced in BALB/c mice following exposure to the carcinogenic chemical 3-methylcholanthrene. To induce spontaneous metastasis, we used two tumor cell clones (B9 and G2) known to differ in their metastatic potential, local tumor growth, H-2 class I expression and sensitivity to natural killer (NK) cells. The metastatic nodes were obtained from the lung, liver and kidney. The results showed: (1) amplification of the c-myc proto-oncogene in original tumor clones as well as in all metastatic nodes; (2) mRNA overexpression without amplification of the K-ras proto-oncogene in the metastatic cells, regardless of their anatomical location; (3) no c-K-ras point mutations at codons 12 and 61, and (4) in general, a statistically significantly reduced in vitro sensitivity of metastatic tumor cells to NK cells as compared with the tumor clones used to induce them (p < 0.05). These results therefore suggest that overexpressed c-K-ras mRNA is important during tumor progression, perhaps rendering metastatic tumor cells more resistant to lysis by NK cells.
Epitope Mapping of Antibodies Recognising the N-Terminal Domain of Simian Virus Large Tumour Antigen
Authors: Lindner Karola , Mole Sara E. , Lane David P. , Kenny Mark K.
Published: April 2003

The large tumour antigen (TAg) of simian virus 40 is the main regulatory protein in viral replication. We have investigated possible functional roles for the N-terminal domain of TAg while defining the epitopes of antibodies binding within that region. The epitopes recognised by eight monoclonal anti-TAg antibodies were identified using synthetic peptides in an enzyme-linked immunosorbent assay. For antibodies PAb 223, 281, 211, 219 and 224, epitopes varied in length between ten and fifteen amino acids. Two antibodies, PAb 210 and PAb 419, could not be mapped any further using this technique. Antibody PAb 416 recognised a pentapeptide WEQWW that could be involved in topoisomerase I binding and possibly in the interaction between topoisomerase I and simian virus reverse transcriptase.
Subclinical Reactivation of Varicella-Zoster Virus in Immunocompromised and Immunocompetent Individuals
Authors: Schünemann S. , Mainka C. , Wolff M.H.
Published: April 2003

The occurrence of subclinical reactivation of varicella-zoster virus (VZV) in peripheral blood mononuclear cells (PBMC) from immunocompetent subjects >60 years old without any signs of VZV-caused illnesses, and from immunocompromised patients was investigated. Altogether, 223 samples were tested by nested ORF 63 PCR assay. In addition, all positive samples were tested by ORF 14, ORF 29 and ORF 63 PCR assays, as well as by ORF 63 and ORF 68 nucleic acid sequence-based amplification assays. In 5 samples, VZV-specific DNA, but no transcripts, could be detected. Three of them belonged to the group of >60-year-olds, 1 was HIV positive, the other was being treated with chemotherapy. The results confirm the observation of other authors that subclinical reactivation occurs in both immunocompromised and healthy individuals. The failure to detect DNA in samples taken from 2 individuals several weeks later excludes a long-lasting infection of VZV in PBMC.
Rubella Virus Genome Diagnosis during Pregnancy and Mechanism of Congenital Rubella
Authors: Katow Shigetaka
Published: April 2003

Fetal infection with rubella virus was diagnosed based on the detection of viral genome in the fetus-derived tissues. While viral genomes were detected in 41 of those 112 cases (36.7%) where rubella virus infection of the mother was apparent, only 7 of 141 cases (5.0%) showed evidence of fetal infection when maternal rubella infection was inapparent. All 184 babies born of genome-negative mothers have no congenital disorder, while 2 out of 7 genome-positive babies have a congenital disorder (28.6%). Rubella virus was not transmitted across the placenta when infection occurred prior to gestation. Transmission rate increased to a maximum level during the first trimester and declined to 0% until 20 weeks of gestation. Interval of viral transmission from the onset of rash in the mother was about 10 days to the placental villi and 20–30 days to the fetus. A phylogenetic tree of 61 virus isolates suggested no difference of virulence/teratogenicity among the virus isolates.
A Putative Host Cell Receptor for Tick-Borne Encephalitis Virus Identified by Anti-Idiotypic Antibodies and Virus Affinoblotting
Authors: Kopecký Jan , Grubhoffer Libor , Kovář Vojtěch , Jindrák Libor , Vokurková Doris
Published: April 2003

Anti-idotypic monoclonal antibodies (anti-ID MAbs) were made against two mouse MAbs that neutralize the infectivity of the tick-borne encephalitis (TBE) virus. Three of the anti-ID MAbs (1) inhibited the binding of respective idiotypic MAb to the TBE virus antigen, (2) inhibited the infectivity of TBE virus when preincubated with virus-susceptible cells, and (3) bound to the surface of virus-susceptible but not virus-nonsusceptible cells. They recognized a 35-kD protein in immunoblotting analysis. Identification of this protein as a component of a putative TBE virus receptor was supported by the viroblot technique. In this assay, two polypeptide signals of 35 and 18 kD were obtained after incubation of blotted cell membrane proteins with the TBE virion antigen.
The Clinical Features of Chronic Hepatitis C Are Not Affected by the Coexistence of Hepatitis B Virus DNA in Patients Negative for Hepatitis B Surface Antigen
Authors: Nirei Kazushige , Kaneko Miki , Moriyama Mitsuhiko , Arakawa Yasuyuki
Published: April 2003

Hepatitis B virus (HBV) DNA has been detected in the sera of hepatitis patients who are negative for hepatitis B surface antigen (HBsAg) by polymerase chain reaction (PCR). The purpose of the present study was to clarify the clinical characteristics of patients with chronic hepatitis C who are negative for serum HBsAg and positive for HBV DNA. The subjects included 49 patients with chronic hepatitis C who were negative for serum HBsAg and 119 blood donors who served as healthy controls. Serum samples were tested for the presence of HBV DNA by the nested PCR method. Serum HBV DNA was detected in 18 (37.7%) of the 49 chronic hepatitis C patients and in none (0%) of the 119 blood donors. Among the hepatitis C patients, HBV DNA was detected in 20.7% of those who were negative for all HBV-associated markers and in 57.1% of those who were positive for one or more HBV-associated marker. The HBV DNA-positive rate among those in each F stage did not significantly differ. The liver function parameters of the HBV DNA-positive and the HBV DNA-negative chronic hepatitis C patients did not significantly differ. These results suggest that hepatitis C virus is frequently coinfected with serum HBsAg-negative HBV, and that the incidence of HBV infection in blood donors is low. However, it is considered that HBsAg-negative HBV infection does not modify the blood biochemical features of chronic hepatitis C.
Sequence Analysis and Variation of EBNA-1 in Epstein-Barr Virus-Related Herpesvirus of Cynomolgus Monkey
Authors: Ohara Nobuya , Hayashi Kazuhiko , Teramoto Norihiro , Oka Takashi , Fujimoto Koji , Yoshikawa Yasuhiro , Castanos-Velez Esmeralda , Biberfeld Peter , Akagi Tadaatsu
Published: April 2003

Objectives: The Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is an important protein for immortalization and tumorigenesis of infected cells. EBNA-1 gene variants may play a role in tumorigenesis. We determined the nucleotide and amino acid (aa) sequences of EBNA-1 in EBV-related herpesviruses from cynomolgus monkeys (cynomolgus-EBV) which induced malignant lymphomas in its natural host and in rabbits, and compared them with sequences of EBV and other lymphocryptoviruses (LCVs). Methods: Polymerase chain reaction and direct sequencing methods were performed using extracted DNA from cynomolgus-EBV-infected cell lines. Results: The amino acid sequences of cynomolgus-EBV EBNA-1 from two cell lines (Si-IIA: 588 aa; Ts-B6: 619 aa) which are antigenically cross-reactive to human EBV EBNA-1 showed homology with human EBV (Si-IIA: 53%; Ts-B6: 58%) and other LCVs from baboons (54 and 52%) and rhesus monkeys (60 and 58%), especially in the C-terminal unique domain. Homology of the EBNA-1 sequence between Si-IIA and Ts-B6 was 92%. The sequence difference between EBV and the related LCVs was manifested mainly in the length of the internal repeat 3-corresponding region, which contains serine in the glycine/alanine repeat region of nonhuman LCVs. Conclusion: Sequence variation of cynomolgus-EBV EBNA-1 from different cell lines was observed. However, their sequences show a relatively high homology with human EBV and share the common features of EBNA-1 of EBV and other LCVs.
Neural Control of Coronary Blood Flow
Authors: Feigl Eric O.
Published: April 2003

Parasympathetic control of coronary blood flow has been extensively studied in dogs, and a clear vasodilator effect not dependent on changes in myocardial metabolism was observed. Parasympathetic vasodilatation is mediated via nitric oxide (EDRF) and is activated during carotid baroreceptor and chemoreceptor reflexes. Intracoronary infusions of acetylcholine in humans results in increased coronary blood flow and epicardial coronary artery dilatation except in atherosclerotic epicardial coronary vessels, which show a paradoxical vasoconstriction. Sympathetic α-adrenoceptor-mediated coronary vasoconstriction has been repeatedly demonstrated whenever there is adrenergic activation of the heart, as during exercise or a carotid sinus baroreceptor reflex in dogs or during a cold pressor reflex in humans. Recent evidence indicates that there is a beneficial effect of this paradoxical vasoconstrictor influence in that it helps preserve flow to the vulnerable inner layer of the left ventricle, but only when both heart rate and coronary flow are high. β-Adrenoceptor-mediated coronary vasodilatation also occurs during adrenergic activation of the heart. The dominant site for β-vasodilatation is in small arterioles, while the dominant site for α-vasoconstriction is in microvessels larger than ∼100 µm diameter. The β-adrenoceptor coronary vasodilatation is an example of feedforward open-loop control that complements the closed-loop negative feedback control by local metabolic factors. The combined feedback and feedforward control mechanism has the advantage of an excellent match between coronary blood flow and myocardial oxygen consumption with a rapid response time but without the instability inherent in high gain feedback systems.
Gene Expression of Endothelin-1 and ETA and ETB Receptors in Human Cirrhosis: Relationship with Hepatic Hemodynamics
Authors: Leivas Albert , Jiménez Wladimiro , Bruix Jordi , Boix Loreto , Bosch Jaime , Arroyo Vicente , Rivera Francisca , Rodés Joan
Published: April 2003

Previous experimental studies have suggested that the paracrine endothelin system may participate in the regulation of hepatic hemodynamics in cirrhosis. The present study assesses the relationship between increased portal pressure and preproET-1, ETA receptor and ETB receptor gene expression in human cirrhosis. PreproET-1, ETA receptor and ETB receptor mRNA abundance was estimated by quantitative PCR in human hepatic tissue from subjects with normal liver and in cirrhotic patients in whom a hepatic hemodynamic study was performed. The expression of the three transcripts was significantly higher in liver samples of cirrhotic patients than in those obtained from subjects without any histological alteration. Moreover, while no significant correlation was found between preproET-1 mRNA abundance and portal pressure, there was a highly significant direct relationship between ETA and ETB receptor gene expression and portal pressure in cirrhotic patients. These results indicate that the liver paracrine endothelin system is overactivated in human cirrhosis and that a direct relationship exists between endothelin receptor mRNA abundance and the degree of portal hypertension in these patients.
Differential Expression of the α1 Type VIII Collagen Gene by Smooth Muscle Cells from Atherosclerotic Plaques of Apolipoprotein-E-Deficient Mice
Authors: Yasuda Osamu , Zhang Sunny H. , Miyamoto Yasuhide , Maeda Nobuyo
Published: April 2003

We have investigated the morphology, growth and gene expression of smooth muscle cell (SMC) cultures derived from advanced atherosclerotic plaques and from non-plaque-containing aorta of individual apolipoprotein-E-deficient mice. The initial outgrowth of cells was faster from plaques (P) than from non-plaque segments (NP), but the cells in P cultures divided more slowly than NP cells in subcultures. By the 6th passage, the general growth pattern, morphology, ploidy and response to mitogenic factors of the cells were no longer consistently different in P and NP cultures. However, by the use of differential display, several transcripts were identified that were differentially expressed in three independent pairs of P and NP cultures. One of the transcripts, from a type VIII collagen gene, was elevated in all the P cultures compared to their NP counterparts even at the 40th passage. The α1 type VIII collagen transcripts were also readily detectable by RT-PCR in freshly dissected plaques, but not in the normal parts of aortas from the apolipoprotein-E-deficient mice. In situ hybridization showed that the transcripts were limited to the fibrous cap of plaques. Thus, SMCs from atherosclerotic plaques produce type VIII collagen and this differential expression continues when the cells are maintained in tissue culture.
Progression of Diabetic Nephropathy
Authors: Phillips A.O. , Janssen U. , Floege J.
Published: April 2003

Nephropathy in patients with type I and II diabetes mellitus is a rapidly increasing problem worldwide. Studies using both glomerular and tubular cells have delineated some of the consequences induced by acute hyperglycemia. In vitro studies have clearly demonstrated that exposure of cultured renal cells, such as glomerular mesangial cells and proximal tubular epithelial cells, to elevated glucose concentrations, may alter cell proliferation and/or extracellular matrix turnover. The latter is effected both directly and indirectly by the alteration of cytokine generation. Furthermore, these in vitro studies have allowed detailed examination of the mechanisms by which exposure of these cells to high ambient glucose concentrations may alter cell function. Extension of these studies to the experimental in vivo situation has confirmed most of the in vitro findings. Important insights gained from models of type I diabetes (i.e. streptocotocin–induced diabetes) as well as type II diabetes (i.e. Goto–Kakizaki (GK) rats and obese Zucker rats) include: (1) The demonstration that increased glomerular cell proliferation and renal matrix accumulation, driven by TGF–β and/or PDGF, occur in streptocotocin–induced diabetes, yet that nephropathy in these rats does not progress to renal failure. (2) The demonstration that prolonged mild type II diabetes does induce morphological changes characteristic of pre–clinical diabetic nephropathy in GK–rats but does not result in albuminuria or progressive renal disease. (3) The demonstration that the association of type II diabetes with hyperlipidemia in obese Zucker rats results in early podocyte damage and subsequent progression to glomerulosclerosis, tubulointerstitial damage, and renal insufficiency. Identification of the mediators involved in the above processes and in particular of the conditions that will determine progression of subclinical morphological changes to overt nephropathy and renal failure will likely result in future novel therapeutic approaches to diabetic nephropathy.
Suppressed Activities of Cathepsins and Metalloproteinases in the Chronic Model of Puromycin Aminonucleoside Nephrosis
Authors: Huang Shaoming , Schaefer Roland M. , Reisch Stefan , Paczek Leszek , Schaefer Liliana , Teschner Markus , Sebekova Katarina , Heidland August
Published: April 2003

Glomerulosclerosis and tubulointerstitial fibrosis are the hallmarks of chronic renal diseases. In the present study, we have investigated the potential involvement of various proteinases in these alterations in the model of puromycin aminonucleoside (PAN) nephrosis. Two groups of male Wistar rats were given either three or seven injections of PAN (2.0 mg/100 g body weight) over a 4– and 12–week period, respectively. The two control groups received saline injections. Activities of cathepsins (B, H and L) were determined in isolated glomeruli and proximal tubules. Moreover, collagenaselike and gelatinaselike activities were analyzed in isolated glomeruli. Three weeks after weekly PAN injection, the rats developed heavy proteinuria (140.8±22.0 vs. 13.5±3.29 mg/day; p<0.001), and at week 11 protein excretion reached 606.6±23.00 vs. 22.8±1.5 mg/day. Renal morphology revealed minimal glomerular mesangial changes at the 4th week after PAN administration. At the 12th week a marked mesangial matrix accumulation as well as severe tubulointerstitial infiltration and fibrosis associated with tubular dilation and atrophy were observed. Glomerular cathepsins B, H, and L and gelatinaselike activities decreased at the 4th week after the first PAN injection and remained at this low level throughout the entire study period. Glomerular collagenaselike activity decreased at the 4th week (p<0.05) and was still mildly lower than that of the control group at the 12th week, but without significance. In the isolated proximal tubules, the activities of cathepsins B, H, and L showed the same pattern of decreases as those found in the glomeruli over the whole experimental period. Taken together, our data in the model of chronic PAN nephrosis suggest that the suppressed activities of cathepsins as well as the decreased gelatinase– and collagenaselike activities participate in the accumulation of extracellular matrix and thereby may contribute to the development of glomerulosclerosis and tubulointerstitial fibrosis.
Grass Carp (Ctenopharyngodon idellus) Bile may Inhibit the Release of Renal Dipeptidase from the Proximal Tubules by Nitric Oxide Generation
Authors: Choi Kyong , Park Sung Wook , Lee Kwang Jae , Lee Hwanghee Blaise , Han Ho Jae , Park Sung Kwang , Park Haeng Soon
Published: April 2003

There are many reports on acute renal failure (ARF) after ingestion of grass carp bile (CB; Ctenopharyngodon idellus). Renal dipeptidase (RDPase; EC 3.4.13.19) is a glycosylphosphatidylinositol–anchored ectoenzyme within the renal proximal tubules (PTs) and is proposed as a diagnostic enzyme of renal disease. We examined the release of RDPase following treatment with CB and various nitric oxide (NO) related compounds in porcine PTs. The RDPase release from PTs was inhibited by CB in a concentration–dependent manner and was also inhibited by sodium nitroprusside (direct NO donor) and L–arginine (NO synthase substrate) in the tested range (0–12 mM). CB–treated (0.1 mg/ml) PTs showed a decreased RDPase activity in comparison with the control group. This inhibition was blocked by 2 mM L–NAME (NO synthase inhibitor) and U73122 (inhibitor of phosphatidylinositol–specific phospholipase C) in a concentration–dependent manner. Eel bile (0–0.1 mg/ml), used as the control, did not significantly affect the RDPase release from PTs. The NO concentration was observed as nitrite, the degradation product of the NO metabolism, increased in proportion to CB and L–arginine. The increase of nitrite to 151.5% by CB treatment (0.1 mg/ml) was blocked by 2 mM L–NAME (95.5%). When the phospholipase C pathway was blocked by 10 and 20 μM U73122, the nitrite generation decreased to 122.7 and 89.4%, respectively. These results strongly suggest that NO generation and the phospholipase C pathway affect the RDPase release from the PTs and that they may be involved in the development of ARF in vivo following CB ingestion. The release of RDPase from PTs could be a useful tool not only for this CB–caused ARF, but also for the elucidation of other biochemical mechanisms.
Recent Advances in Autonomic Function Tests of the Cardiovascular System in Children
Authors: Tanaka Hidetaka , Tamai Hiroshi
Published: April 2003

Recent advances in computer technology have made it possible to noninvasively determine fast and dynamic changes in autonomic nervous activity in humans. Power spectral analysis of heart rate variation, beat-to-beat blood pressure analysis, skin blood flow by the laser Doppler technique, sensitive sudorometry and direct measurement of sympathetic nervous discharge have been successfully applied in adults, but there are still only few studies reported in children and adolescents. This article reviews the usefulness of these autonomic function tests in the pediatric field including reliability and methodological limits. Power spectral analysis of heart rate variability seems to be a new potential method, but there have been only few studies in children. Orthostatic maneuvers with noninvasive beat-to-beat measurement of finger arterial pressure, especially during active standing, is useful for the evaluation of orthostatic intolerance in children as well as adults with autonomic failure. A new pharmacological method using multiple autonomic agents might indicate a more precise information including alpha- and beta-adrenoceptor sensitivity. It should be realized that a single test cannot identify impaired autonomic functions, and a combination of several autonomic tests should be employed. Moreover, age-related changes and racial differences in autonomic function should be considered when interpreting obtained results.
The Etiology of Acute Scrotal Swelling on Surgical Exploration among Children and Adolescents in Jahra
Authors: Grover Vinod K. , Adib Salim M. , Joseph Leons , Nur Ali M. Ali
Published: April 2003

Objective: To describe the clinical presentation as well as the outcome of surgically explored acute scrotal swellings among children and adolescents recorded at the Al-Jahra Hospital, Kuwait during the period 1985–1995. Methods: Hospital records of 120 cases were reviewed. Results: Seventeen percent of the cases were found to be testicular torsions (TT) and 40% torsions of testicular appendages (TAT). Other etiologies included traumatic swelling (15%), idiopathic edema (13%), epididymo-orchitis (10%), hydroele (4%) and others (2%). Ages of patients ranged from 6 months to 18 years, averaging 9.3 years (SD = 2.9) for TAT cases and 10.1 years (SD = 6.4) for TT cases. Swelling and pain were located on the left side for 65% of the torsion cases. Direct trauma was reported in 22% of the torsion cases. In 90% of TT cases, orchidopexy was performed with success. Subsequent testicular atrophy occurred in only 1 patient who had symptoms for more than 48 h prior to surgery. Orchidectomy was directly performed on necrosed testes in a patient with signs lasting more than 48 h, and another patient with signs lasting 4 days. Conclusions: Primary health care physicians in Jahra district should continue to educate parents and adolescents to recognize the gravity of scrotal pain, and the importance of early response as a way of avoiding testicular necrosis.
Rising Incidence of Beta-Lactam Resistance among Pneumococci in Kuwait: Failure of Cefotaxime Therapy in Pneumococcal Meningitis
Authors: Johny Molly , Narayanan S. , Murad M.A.
Published: April 2003

Objective: Pneumococcal resistance to antimicrobial agents has become a global problem. This study was done to evaluate the resistance of Streptococcus pneumoniae (pneumococci) to penicillin G in Kuwait, and to assess the efficacy of other β-lactam agents (cefotaxime or ceftriaxone) in the management of invasive pneumococcal infections. Methods: Surveillance studies were done in a general teaching hospital in Kuwait for penicillin G resistance (intermediate or high level resistance) of pneumococci isolated from clinical specimens by agar diffusion method using oxacillin (1 µg) disc. In cases of pneumococcal meningitis, minimum inhibitory concentrations (MICs) of penicillin and cefotaxime were determined by agar dilution method, to differentiate intermediate resistance and high level resistance. Results: An increase in the incidence of penicillin G-resistant pneumococci from 20.6% (94 out of 457 isolates) for the period 1985–1988 to 28.5% (40 out of 140 isolates) during 1992–1994 and 38.3% (43 out of 112 isolates) during 1995/96 was observed. During the period 1992–1994, 40–45% (7 out of 16 isolates) blood culture isolates of pneumococci were intermediate or highly resistant to penicillin. Therapy with cefotaxime or ceftriaxone produced a positive outcome in 6 of the 7 patients. However, failure of cefotaxime therapy to achieve a cure was noted in 1 patient who had systemic lupus erythematosus and intermediate resistant (penicillin MIC 0.5 mg/l; cefotaxime MIC 1 mg/l) pneumococcal septicaemia complicated with meningitis. A cure was however achieved with the addition of chloramphenicol to the regimen. Conclusion: Resistance of pneumococci to penicillin G and other β-lactam agents is increasing in Kuwait. Penicillin-resistant pneumococcal bacteraemia in an immunosuppressed setting, if managed with cefotaxime or ceftriaxone, should be given high doses (cefotaxime 12 g/day or ceftriaxone 4 g/day) from the beginning. Cases of pneumococcal meningitis with cefotaxime-intermediate resistant strains (MIC 0.5–1 mg/l) on monotherapy consisting of cefotaxime or ceftriaxone should be viewed with caution. Chloramphenicol or vancomycin with rifampicin should be added to the regimen if therapeutic failure is suspected.
Transport Kinetics of Alpha-Aminoisobutyric Acid in the Perfused Human Placental Lobule in vitro
Authors: Nandakumaran Moorkath , Makhseed Ma’asoumah , Al-Rayyes Samer , Sugathan Thattaruparambil N.
Published: April 2003

Objective: The transports kinetics of α-aminoisobutyric acid (AIB) has been investigated in the human placenta in vitro using perfusion of isolated placental lobules. Methods: NCTC 135 tissue culture medium diluted with Earle’s salt solution was used as the perfusate, and tritiated water was used as the reference marker. Results: The transport fraction of AIB averaged 13.2% of that of tritiated water in 5 single-bolus injection experiments. The differential transport rates for 10, 25, 50, 75 and 90% cumulative efflux in the fetal vein of the study and the reference substances differed significantly as well. The transport kinetic parameters as area under the curve, clearance, elimination constant, time for maximum response, absorption rate and elimination rate of the amino acid averaged 0.12, 19.8, 0.78, 1.28, 0.10 and 0.06 times, respectively. Plotting of relative AIB transport ratios as a function of perfusion time demonstrated the active nature of amino acid transport in our perfusion conditions. Conclusions: The transport and kinetic parameters employed in the study may be useful in assessing dynamic placental membrane function of A type amino acids and other substances in varying experimental conditions as well as in disease states.
Acute Diverticulitis: 5 Years Experience in a Teaching Hospital in Kuwait
Authors: Afifi El-Sayed M. , Juma T.H. , Al-Sayer Hilal
Published: April 2003

Objective: To evaluate the diagnostic and therapeutic modalities of all patients admitted to a hospital over a period of time. Methods: Review of the medical files of 60 cases of colonic diverticulitis seen over a period of 5 years at the Amiri Hospital, Kuwait, which serves a population of about 150,000. Results: Two thirds of our patients were females. The age at presentation was lower (56.6 year) than in the West. The commonest presenting manifestation was left iliac fossa pain and tenderness. Plain abdominal X-ray and an erect chest X-ray were the most valuable diagnostic tools. Ultrasound scan was helpful in percutaneous drainage of pericolic abscesses. Combined CT scan with water-soluble enemas is recommended once the patient’s condition is stable. Conclusion: The majority of conservatively managed patients responded well to treatment. Surgery should be reserved for those presenting with generalized peritonitis (6/60), for the very few who do not respond to the conservative modality (4/54), or those who come back with recurrent diverticulitis.
Risk Factors and Outcome in Patients with Severe Acute Asthma Requiring Mechanical Ventilation
Authors: Onadeko B.O. , Khadadah M.E. , Mustafa H.T. , Metwali K.E.H.
Published: April 2003

Objective: Severe acute asthma has been recognized as a cause of significant morbidity and mortality. Mechanical ventilation may be necessary to support life in the most critically ill patients. In this study, we set out to identify factors which may affect the outcome of management in severe acute asthma. Methods: Patients with severe acute asthma admitted to the intensive care unit of the Mubarak Al-Kabeer Hospital, Kuwait, over a 2-year period (1996 and 1997) were recruited for the study. The clinical features at presentation, drug treatment and the type of ventilation used, the duration of ventilation and the outcome were monitored. PaCO2, pH, and ventilation parameters were monitored. Results: Thirty patients selected from a total of 36 patients admitted to the intensive care unit with diagnosis of severe acute asthma were studied. Twenty-one (70%) of these patients were mechanically ventilated. The duration of ventilation, and the duration in the intensive care unit for the patients who developed complications and for those who did not were found to be significant (p < 0.02 and p < 0.01, respectively). There was no statistical difference in patients with or without complications in the following parameters at presentation: pulse rate, respiratory rate, pH, PaCO2, duration of onset of symptoms, peak airway pressure, minute ventilation, tidal volume, and fraction of inspired oxygen. Two (9.5%) patients died. Factors found to affect outcome include duration of intubation, duration in intensive care unit and pulse rate at presentation. Conclusion: This study revealed that mechanical ventilation is effective and safe in management when it is critically applied and monitored.
Mutation and Linkage Analysis in Genetic Counseling for Phenylketonuria in Kuwait
Authors: Samilchuk Elena , Al-Suliman Ibrahim , Naqi Gadeer , Al-Awadi Sadika
Published: April 2003

Objective: Phenylketonuria (PKU) is caused by mutations in the PAH gene. More than 250 PAH mutations have been identified, and their distribution among different populations varies significantly. Though PKU is prevalent in Kuwait, the molecular bases of the underlying genetic variants have never been studied. Methods: DNA from 20 PKU patients belonging to 11 families of Arabic origin as well as 30 healthy relatives was extracted using a ‘salting-out’ method. DNA samples were analyzed by polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) tests for 5 common PAH mutations (IVS10nt546, R261Q, IVS12nt1, IVS2nt1, R408W). Linkage analysis and PAH haplotyping was carried out by the study of variable number tandem repeat and BglI, PvuII-a, PvuII-b, MspI, XmnI polymorphism by PCR or PCR/RFLP tests. Results: Seven patients from 4 families were found to be homozygous for IVS10nt546, thus proving the frequency of this mutation among PKU chromosomes in Kuwait to be 36.4%. The four other PAH mutations were absent among the patients studied. The linkage analysis was informative in all but 1 of the families. Seven PAH haplotypes were identified among 22 PKU chromosomes from Kuwait. All the IVS10nt546 chromosomes had identical haplotype.