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1.
Langenbecks Arch Surg ; 409(1): 200, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38935194

ABSTRACT

PURPOSE: Robotic assisted surgery is an alternative, fast evolving technique for performing colorectal surgery. The primary aim of this single center analysis is to compare elective laparoscopic and robotic sigmoid colectomies for diverticular disease on the extent of operative trauma and the costs. METHODS: Retrospective analysis from our prospective clinical database to identify all consecutive patients aged ≥ 18 years who underwent elective minimally invasive left sided colectomy for diverticular disease from January 2016 until December 2020 at our tertiary referral institution. RESULTS: In total, 83 patients (31 female and 52 male) with sigmoid diverticulitis underwent elective minimally invasive sigmoid colectomy, of which 42 underwent conventional laparoscopic surgery (LS) and 41 robotic assisted surgery (RS). The mean C-reactive protein difference between the preoperative and postoperative value was significantly lower in the robotic assisted group (4,03Ā mg/dL) than in the laparoscopic group (7.32Ā mg/dL) (p = 0.030). Similarly, the roboticĀ“s hemoglobin difference was significantly lower (p = 0.039). The first postoperative bowel movement in the LS group occurred after a mean of 2.19 days, later than after a mean of 1.63 days in the RS group (p = 0.011). An overview of overall charge revealed significantly lower total costs per operation and postoperative hospital stay for the robotic approach, 6058 Ā€ vs. 6142 Ā€ (p = 0,014) not including the acquisition and maintenance costs for both systems. CONCLUSION: Robotic colon resection for diverticular disease is cost-effective and delivers reduced intraoperative trauma with significantly lower postoperative C-reactive protein and hemoglobin drift compared to conventional laparoscopy.


Subject(s)
Colectomy , Cost-Benefit Analysis , Laparoscopy , Robotic Surgical Procedures , Humans , Male , Female , Robotic Surgical Procedures/economics , Laparoscopy/economics , Laparoscopy/methods , Colectomy/economics , Colectomy/methods , Retrospective Studies , Middle Aged , Aged , Adult , Sigmoid Diseases/surgery , Sigmoid Diseases/economics , Colon, Sigmoid/surgery , Diverticulitis, Colonic/surgery , Diverticulitis, Colonic/economics
2.
J Clin Invest ; 99(10): 2452-61, 1997 May 15.
Article in English | MEDLINE | ID: mdl-9153289

ABSTRACT

Galectin-9, a beta-galactoside binding lectin, has recently been isolated from murine embryonic kidney. In this study, its biological functions and expression in embryonic, newborn, and adult mice tissues were investigated. By Northern blot analyses, it was found widely distributed and its expression was developmentally regulated. In situ hybridization studies revealed an accentuated expression of galectin-9 in liver and thymus of embryonic mice. In postnatal mice, antigalectin-9 immunoreactivity was observed in various tissues, including thymic epithelial cells. The high expression of galectin-9 in the thymus led us to investigate its role in the clonal deletion of thymocytes. Fusion proteins were generated, which retained lactose-binding activity like the endogenous galectin-9. Galectin-9, at 2.5 microM concentration, induced apoptosis in approximately 30% of the thymocytes, as assessed by terminal deoxytransferase-mediated dUTP nick end labeling method. The apoptotic effect was dose dependent and lactose inhibitable. At higher concentrations, it induced homotypic aggregation of the thymocytes. Electron microscopy revealed approximately 60% of the thymocytes undergoing apoptosis in the presence of galectin-9. By immunofluorescence microscopy, some of the thymocytes undergoing apoptosis had plasmalemmal bound galectin-9. Galectin-9 failed to induce apoptosis in hepatocytes. Taken together, these findings indicate that galectin-9, a developmentally regulated lectin, plays a role in thymocyte-epithelial interactions relevant to the biology of the thymus.


Subject(s)
Aging/metabolism , Apoptosis , Galectins , Gene Expression Regulation, Developmental , Lectins/biosynthesis , Lectins/pharmacology , Transcription, Genetic , Animals , Animals, Newborn , Cells, Cultured , Clonal Anergy , Epithelium/physiology , Fetus , Intestine, Small/physiology , Kidney/physiology , Lectins/physiology , Liver/cytology , Liver/drug effects , Liver/physiology , Mice , Mice, Inbred ICR , Organ Specificity , RNA, Messenger/biosynthesis , T-Lymphocytes/cytology , T-Lymphocytes/drug effects , T-Lymphocytes/physiology , Thymus Gland/immunology , Thymus Gland/physiology
3.
J Clin Invest ; 98(11): 2478-88, 1996 Dec 01.
Article in English | MEDLINE | ID: mdl-8958210

ABSTRACT

An organ culture system was used to study the effect of D-glucose on embryonic kidneys, and to delineate the mechanism(s) relevant to their dysmorphogenesis. Metanephroi were cultured in the presence of 30 mM D-glucose. A notable reduction in the size and population of nephrons was observed. Ureteric bud branches were rudimentary and the acuteness of their tips, the site of nascent nephron formation, was lost. Metanephric mesenchyme was atrophic, had reduced cell replication, and contained numerous apoptotic cells. Competitive reverse transcriptase-PCR analyses and immunoprecipitation studies indicated a decrease in expression of heparan sulfate proteoglycan (perlecan). Status of activated protein-2 was evaluated since its binding motifs are present in the promoter region of the perlecan gene. Decreased binding activity of activated protein-2, related to its phosphorylation, was observed. D-glucose-treated explants also had reduced levels of cellular ATP. Exogenous administration of ATP restored the altered metanephric morphology and reduced [35S]sulfate-incorporated radioactivity associated with perlecan. The data suggest that D-glucose adversely affects the metanephrogenesis by perturbing various cellular phosphorylation events involved in the transcriptional and translational regulation of perlecan. Since perlecan modulates epithelial/mesenchymal interactions, its deficiency may have led to the metanephric dysmorphogenesis and consequential atrophy of the mesenchyme exhibiting accelerated apoptosis.


Subject(s)
Gene Expression/drug effects , Glucose/toxicity , Heparan Sulfate Proteoglycans , Kidney/embryology , Teratogens/toxicity , Actins/biosynthesis , Adenosine Triphosphate/metabolism , Adenosine Triphosphate/pharmacology , Animals , Base Sequence , Collagen/biosynthesis , DNA Primers , Female , Fetus , Fibronectins/biosynthesis , Heparitin Sulfate/biosynthesis , Integrins/biosynthesis , Kidney/drug effects , Kidney/pathology , Laminin/biosynthesis , Mesoderm/drug effects , Mesoderm/pathology , Mesoderm/ultrastructure , Mice , Mice, Inbred ICR , Microscopy, Electron , Molecular Sequence Data , Nephrons/drug effects , Nephrons/metabolism , Nephrons/pathology , Organ Culture Techniques , Polymerase Chain Reaction , Pregnancy , Proteoglycans/biosynthesis , Receptors, Fibroblast Growth Factor/biosynthesis , Sulfates/metabolism , Thymidine/metabolism
4.
J Clin Invest ; 90(4): 1205-18, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1401058

ABSTRACT

Because various fetal anomalies are seen in diabetic offspring, we examined the effects of sugars on proteoglycans (PGs): extracellular matrix (ECM) macromolecules modulating morphogenesis. 13-d-old mouse metanephric kidney explants were exposed to mannose for 7 d and labeled with [35S]sulfate, [35S]-methionine, or [3H]thymidine. Mannose exposure caused reduction in kidney size and disorganization of ureteric bud branches with inhibition of glomerulogenesis. Tissue autoradiographic and immunofluorescence studies indicated decreased expression of sulfated PGs in ECMs. Helix pomatia lectin binding to D-GalNAc residues of glomerular epithelial cells was also reduced. Biochemical studies revealed decreased synthesis of sulfated PGs. PGs were of lower molecular weight with reduced charge density and increased chondroitin/heparan sulfate ratio. Immunoprecipitation of [35S]methionine-labeled proteins confirmed the reduction of PG core peptides. Intracellular ATP levels were reduced. The addition of 0.1 mM ATP to culture media restored kidney size, the population of glomeruli, and the synthesis and characteristics of PGs to almost normal, with no detectable effect on the replication of cells as determined by [3H]thymidine incorporation. The effect of ATP could be partially blocked by the P2y-purinoreceptor, i.e., reactive blue-2. Data suggest that mannose causes energy depletion by cellular ATP consumption and thus selectively alters the synthesis of heavily glycosylated proteins with rapid turnover, such as PGs, resulting in renal dysmorphogenesis.


Subject(s)
Adenosine Triphosphate/physiology , Kidney/abnormalities , Mannose/toxicity , Proteoglycans/physiology , Animals , Autoradiography , Congenital Abnormalities/etiology , Immunohistochemistry , Kidney/embryology , Kidney/pathology , Methionine/metabolism , Mice
5.
Biochim Biophys Acta ; 968(3): 331-9, 1988 Mar 11.
Article in English | MEDLINE | ID: mdl-2449912

ABSTRACT

Radioactively labelled transferrin was injected into rats intravenously and its uptake and subcellular distribution in the liver was investigated. The amount of radioactivity in the liver remained constant from 10 min after injection. It was not influenced by asialoglycoproteins. The radioactive label was identified as asialotransferrin. After subcellular fractionation by differential and zonal sucrose density-gradient centrifugation the label was enriched in a low-density endocytic compartment showing fluorescence quenching of acridine orange and N-ethylmaleimide-sensitive ATPase activity. The data fit into a model of continuous transferrin-receptor-mediated recycling through the hepatocyte's endocytic compartment.


Subject(s)
Asialoglycoproteins , Liver/metabolism , Transferrin/pharmacokinetics , Animals , Cell Membrane/metabolism , Centrifugation, Density Gradient , Endocytosis , Fetuins , Injections, Intravenous , Liver/ultrastructure , Lysosomes/metabolism , Male , Mitochondria, Liver/metabolism , Rats , Tissue Distribution , Transferrin/administration & dosage , Transferrin/analogs & derivatives , Transferrin/pharmacology , alpha-Fetoproteins/pharmacology
6.
Arch Intern Med ; 157(17): 1921-9, 1997 Sep 22.
Article in English | MEDLINE | ID: mdl-9308504

ABSTRACT

A critical review of published literature was performed to assess the impact of medication adherence on morbidity and mortality among patients with or at risk for coronary artery disease and congestive heart failure. Twenty-one original research articles that met our inclusion criteria and related medication adherence to morbidity and mortality are summarized. No clinical trials that specifically tested the impact of a compliance-enhancing intervention on outcome in coronary heart disease were identified. Among 12 studies that compared hospitalization rates and mortality between adherers and nonadherers, 7 showed a significant relationship between medication adherence and outcomes. Three studies showed that adherence to placebo was associated with improved outcomes, suggesting that adherent behavior may be a marker of better prognosis or confers a protective effect on patients with coronary heart disease. Further study is necessary to determine whether adherent behavior can be taught and whether compliance-enhancing strategies improve outcomes in coronary heart disease.


Subject(s)
Coronary Disease/drug therapy , Treatment Refusal , Clinical Trials as Topic , Coronary Disease/mortality , Female , Heart Failure/drug therapy , Heart Failure/mortality , Humans , Male , Risk Factors , Treatment Outcome , Treatment Refusal/statistics & numerical data
7.
Eur J Cell Biol ; 65(2): 378-91, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7720730

ABSTRACT

Many hormones/factors influence the total body growth and development during embryonic life, and very few studies have been carried out to ascertain their effects on the individual organ system. In this study, the effect of exogenous insulin-like growth factor-I (IGF-I) on embryonic kidneys was investigated, and correlated with phenotypic and gene expression and synthesis of extracellular matrix (ECM) proteoglycans (PGs). Antisense experiments were carried out to elucidate the role of endogenous (IGF-I in metanephric development. Mouse metanephroi, harvested at 13th day of gestation, were exposed to IGF-I (100 ng/ml) in an organ culture for 7 days. An enlargement of the metanephroi with accentuation of its lobules, and increase in the nephron population and [3H]thymidine incorporation was observed. Immunofluorescence studies and Southern blot analysis of polymerase chain reaction products indicated augmented expression of the ECM PGs. A heavy concentration of [35S]sulfate-associated radioactivity over the tips of ureteric bud branches and ECM components of maturing glomeruli was seen. Maximal effect of radioincorporation was observed on day-4 of the culture, the period when the concentration of endogenous IGF-I is the highest. PGs synthesized had elevated proportions of chondroitin sulfate vs heparan sulfate and of free chains, and reduced charge-density characteristics. Immunoprecipitation studies of [35S]methionine-labeled glycoproteins revealed an increased synthesis of core-peptide of the PGs. IGF-I antisense oligonucleotide caused retardation in the growth of the kidneys along with the decrease in de novo synthesis of PGs. These findings indicate that IGF-I, a polypeptide essential to the renal growth and development, has a trophic effect on the embryonic kidney during the postinductive period of metanephric development, and the observed response has a temporal relationship with the increased synthesis of the PGs.


Subject(s)
Extracellular Matrix/metabolism , Insulin-Like Growth Factor I/pharmacology , Nephrons/drug effects , Proteoglycans/biosynthesis , Animals , Antisense Elements (Genetics) , Autoradiography , Base Sequence , Gene Expression , Immunohistochemistry , Mice , Molecular Sequence Data , Morphogenesis , Nephrons/growth & development , Precipitin Tests
8.
Endocrinology ; 134(1): 358-70, 1994 Jan.
Article in English | MEDLINE | ID: mdl-8275951

ABSTRACT

Hypophysectomy leads to growth retardation of the animals, which is believed to be related to the deficiency of certain growth factors influencing the metabolism and synthesis of glycoproteins. Conceivably, the extracellular matrix proteins (ECM) are also affected, in particular the sulfated proteoglycans (PGs). In this study, we investigated the status of the ECM proteins and sulfated PGs, and the expression and de novo synthesis of insulin-like growth factor-I (IGF-I) receptor (IGF-IR) in hypophysectomized (Hx) rats. The studies were extended to ascertain the effect of IGF-I on the de novo synthesis of glomerular ECM glycoproteins in Hx rats. An organ perfusion system was used in which isolated rat kidneys were radiolabeled with either [35S]sulfate or [35S]methionine, after which IGF-IR and ECM macromolecules were isolated and characterized by biochemical and tissue autoradiographic procedures. Hypophysectomy resulted in a fall in IGF-I levels in serum and isolated renal glomeruli. Reduced synthesis of ECM proteins, i.e. type IV collagen, laminin, and sulfated PGs, and reduced synthesis and mRNA expression of IGF-IR were observed in the glomeruli of the Hx rats. Tissue autoradiographic studies revealed a reduced grain density (concentration of radiation) over various cell types of the glomerulus. After inclusion of IGF-I in the perfusion medium not only was synthesis restored to normal in Hx rats, but it far exceeded the control basal values in the intact animals. Under the influence of IGF-I, the magnitude of increased synthesis of the ECM proteins, in particular the sulfated PGs, was highly accentuated in the kidneys of the Hx group compared to the controls. Also, a remarkably increased [35S]sulfate incorporation was observed in the glomerular mesangial cells. The analysis of IGF-IR by specific binding studies revealed a decreased concentration of the receptors, but an increased IGF-I-binding affinity, the latter of which probably contributed to the IGF-I-induced accentuated synthesis of renal glomerular PGs in the Hx group.


Subject(s)
Hypophysectomy , Insulin-Like Growth Factor I/pharmacology , Kidney/metabolism , Proteoglycans/metabolism , Receptor, IGF Type 1/physiology , Animals , Autoradiography , Chromatography , Culture Media/metabolism , Extracellular Space/metabolism , Glycoproteins/metabolism , Glycosaminoglycans/metabolism , Kidney Glomerulus/cytology , Kidney Glomerulus/metabolism , Methionine/metabolism , Rats , Rats, Sprague-Dawley , Receptor, IGF Type 1/metabolism
9.
Microsc Res Tech ; 39(3): 261-84, 1997 Nov 01.
Article in English | MEDLINE | ID: mdl-9372499

ABSTRACT

Mammalian nephrogenesis constitutes a series of complex developmental processes in which there is a differentiation and rapid proliferation of pluripotent cells leading to the formation of a defined sculpted tissue mass, and this is followed by a continuum of cell replication and terminal differentiation. Metanephrogenesis ensues with the intercalation of epithelial ureteric bud into loosely organized metanephric mesenchyme. Such an interaction is reciprocal, such that the intercalating ureteric bud induces the conversion of metanephric mesenchyme into an epithelial phenotype, while the mesenchyme stimulates the iterations of the ureteric bud. The induced mesenchyme then undergoes a series of developmental stages to form a mature glomerulus and tubular segments of the kidney. Coincidental with the formation of these nephric elements, the developing kidney is vascularized by the process of vasculogenesis and angiogenesis. Thus, the process of metanephric development is quite complex, and it involves a diverse group of molecules who's biological activities are inter-linked with one another and they regulate, in a concerted manner, the differentiation and maturation of the mammalian kidney. This diverse group of molecules include extracellular matrix (ECM) proteins and their receptors, ECM-degrading enzymes and their inhibitors, growth factors and their receptors, proto-oncogenes and transcription factors. A large body of literature data are available, which suggest a critical role of these molecules in metanephric development, and this review summarizes the recent developments that relate to metanephrogenesis.


Subject(s)
Kidney/embryology , Animals , Cell Adhesion Molecules/analysis , Epidermal Growth Factor/analysis , Extracellular Matrix/chemistry , Genes, Tumor Suppressor , Humans , Integrins/analysis , Kidney/chemistry , Proto-Oncogenes , Receptors, Growth Factor/analysis , Somatomedins/analysis , Transforming Growth Factor alpha/analysis
10.
Orv Hetil ; 132(51): 2851-2, 2857-8, 1991 Dec 23.
Article in Hungarian | MEDLINE | ID: mdl-1762762

ABSTRACT

In the diagnostics of the coronary artery disease different exercise tests are well-known to be important. On the basis of the increasing number of publications of the eighties the authors examined the applicability of dobutamin stress test in 89 patients, whose anamnesis did not contain any justification of coronary artery disease. All patients were examined by coronarography. The authors compared the results of different tests with the results of coronarography. They found the sensitivity of dobutamin stress test significantly higher and its specificity--although not significantly--lower, than the dynamic treadmill tests, however the combination of the two methods resulted in very good sensitivity and acceptable specificity.


Subject(s)
Coronary Disease/diagnosis , Dobutamine , Heart Function Tests/methods , Coronary Angiography/methods , Coronary Disease/diagnostic imaging , Exercise Test , Female , Humans , Male , Middle Aged
11.
Orv Hetil ; 134(18): 963-6, 1993 May 02.
Article in Hungarian | MEDLINE | ID: mdl-8483589

ABSTRACT

Authors performed dobutamin stress test since 1987 and combined their examinations with 2D-echocardiography in case of suspected coronary artery disease since October 1991. In this study they report on their experiences obtained in the course of the first 32 examinations. The results of the dobutamine stress echocardiography were analysed on the basis of coronarography which was performed in every patient. According to their observations dobutamine stress echocardiography has very good sensitivity and specificity and it is practically a harmless method, but as it requires instruments, assistants, time and work. Authors recommend the method first of all as a complementary to the physical loading method as well as alternative loading examination.


Subject(s)
Coronary Disease/diagnostic imaging , Dobutamine , Echocardiography , Exercise Test , Female , Humans , Male
14.
Anal Biochem ; 207(1): 40-3, 1992 Nov 15.
Article in English | MEDLINE | ID: mdl-1336936

ABSTRACT

We present a facile procedure for measuring adenylyl cyclase activity which circumvents the two-step chromatographic purification of 32P-labeled cAMP. cAMP produced by stimulated cell membrane preparations is easily purified by organic extraction and thus available for quantification using tritium-labeled tracer cAMP and commercially available cAMP-binding protein. The quantification of cAMP is unaffected by the extraction procedure and sample handling. Data obtained by this method were identical to those obtained by the chromatographic method. This procedure could be shown to be suitable for measuring receptor-mediated adenylyl cyclase modulation.


Subject(s)
Adenylyl Cyclases/analysis , Cyclic AMP Receptor Protein , Cyclic AMP/analysis , Alprostadil/pharmacology , Carrier Proteins/metabolism , Cell Membrane/drug effects , Cell Membrane/metabolism , Cells, Cultured , Chemistry Techniques, Analytical/methods , Chloroform , Cyclic AMP/biosynthesis , Embryo, Mammalian , Humans , Kidney/cytology , Kinetics , Methanol , Receptors, Cyclic AMP/metabolism , Stimulation, Chemical , Tritium
15.
J Biol Chem ; 268(7): 4637-42, 1993 Mar 05.
Article in English | MEDLINE | ID: mdl-8383121

ABSTRACT

In guanine nucleotide-binding regulatory protein- (G protein) coupled receptors, an amphipathic alpha-helix has been postulated to be the common structural determinant in the NH2- and COOH-terminal portions of the third intracellular loop representing the major interaction site with the G proteins. Here we assessed the ability of six peptides derived from these sites of the human dopamine D1-, D2-, and beta 1-adrenergic receptors to either activate G proteins directly or to uncouple the activity of their respective receptors in a native membrane environment. In addition, the cross-reactivity was analyzed. Nonspecific effects occurring at high concentrations were differentiated from G protein-specific effects. The peptide D2N derived from the NH2-terminal part of the third intracellular loop of the dopamine D2 receptor was the only one capable of specifically reversing the action of its receptor, the dopamine-mediated inhibition of the adenylyl cyclase. Furthermore, only D2N stimulated pertussis toxin-sensitive G proteins. However, D2N as the only peptide exhibiting specific effects did not exhibit the predicted amphipathic alpha-helix observed for mastoparan (Higashijima, T., Burnier, J., and Ross, E. M. (1990) J. Biol. Chem. 265, 14176-14186) as demonstrated by circular dichroism spectroscopy. In contrast, a peptide for which a certain degree of helicality was verified spectroscopically (D1C) was neither active in GTPase and adenylyl cyclase determinations, nor did it block the receptor-mediated cyclase activation. Hence, the amphipathic alpha-helix does not represent the main structural determinant for the receptor-G protein interaction site.


Subject(s)
GTP-Binding Proteins/metabolism , Peptide Fragments/metabolism , Receptors, Adrenergic, beta/metabolism , Receptors, Dopamine D1/metabolism , Receptors, Dopamine D2/metabolism , Adenylyl Cyclases/metabolism , Amino Acid Sequence , Cell Membrane/metabolism , Cells, Cultured , Enzyme Activation , GTP-Binding Proteins/chemistry , Humans , Molecular Sequence Data , Peptide Fragments/chemical synthesis , Protein Conformation , Receptors, Adrenergic, beta/chemistry , Receptors, Adrenergic, beta/genetics , Receptors, Dopamine D1/chemistry , Receptors, Dopamine D1/genetics , Receptors, Dopamine D2/chemistry , Receptors, Dopamine D2/genetics , Transfection
16.
Lab Invest ; 76(5): 671-81, 1997 May.
Article in English | MEDLINE | ID: mdl-9166286

ABSTRACT

The offspring of severe juvenile diabetics suffer from a multitude of congenital anomalies, including genito-urinary defects. Whether these defects are related to hyperglycemic states remains to be determined. In this study, the effect of glucose on metanephric development and extracellular matrix proteoglycans (PG), the regulators of morphogenesis, was investigated. Metanephric explants, harvested at Day 13 of gestation, were exposed to 30 mM of D-glucose for 1 to 7 days in an organ culture system. Light microscopy revealed a significant reduction in the size of explants and the nephron population in metanephroi exposed to glucose. A marked dysmorphogenesis of the ureteric bud branches was also observed. They were swollen and had blunted tips. The latter are the site of nascent nephron formation. Electron microscopy revealed malformation of the S-shaped body nephrons, which had poorly formed clefts and lacked cells in their distal convolutions. The precapillary stage glomeruli showed effacement of the foot processes, attenuation of the glomerular basement membrane, decreased surface microvilli, and an increased number of intercellular junctions. Immunofluorescence microscopy indicated a decreased reactivity of antibody directed against basement membrane heparan sulfate-PG. By light microscopy-autoradiography, a generalized decrease in [35S] sulfate incorporation was observed, especially at the tips of the ureteric bud branches. Electron microscopy-autoradiography revealed a significant decrease in the silver grain density (concentration of radiation) in the matrix compartment of the nephrons, i.e., cleft of the S-shaped body and glomerular basement membrane of the precapillary-stage glomeruli. Biochemical studies revealed a decrease in the incorporated radioactivity associated with the fraction of PG. The newly synthesized PG had a reduction in their molecular weight and charge-density characteristics but had an increased proportion of chondroitin sulfate. These data suggest that D-glucose induces marked dysmorphogenesis of the embryonic kidney during in vitro metanephric development and that these alterations may be related to perturbations in the de novo synthesis of PG, one of the essential morphogenetic regulators of the extracellular matrix.


Subject(s)
Glucose/physiology , Kidney/embryology , Kidney/metabolism , Proteoglycans/metabolism , Animals , Autoradiography , Female , Immunohistochemistry , Kidney/drug effects , Kidney/pathology , Kidney/ultrastructure , Mice , Mice, Inbred ICR , Nephrons/drug effects , Nephrons/embryology , Nephrons/metabolism , Nephrons/pathology , Nephrons/ultrastructure , Organ Culture Techniques , Proteoglycans/biosynthesis , Proteoglycans/drug effects
17.
Kidney Int ; 39(6): 1140-55, 1991 Jun.
Article in English | MEDLINE | ID: mdl-1895669

ABSTRACT

Effect of aminonucleoside of puromycin (PAN) on metanephric development and proteoglycans (PGs) was investigated. Murine metanephric tissues, obtained on the thirteenth day of gestation, were exposed to PAN in a culture medium for one to seven days and processed for morphological, histochemical and immunofluorescent studies. For tissue autoradiographic and biochemical studies, kidneys were labelled with a precursor product of PGs, that is, [35S]-sulfate. A generalized decrease in the glomerular population along with swelling and deformation in the ureteric bud branches was observed. These changes were accompanied with a diminution in the total incorporated radioactivity and a reduction in the autoradiographic grains, especially over the tips of ureteric bud branches. Sepharose CL-4B chromatography revealed a major high molecular weight PG (Mr greater than 2.5 x 10(6], and a relative increase in the chondroitinase-ABC sensitive PGs. The media PGs were of relatively smaller size. Immunoprecipitation experiments with [35S]-methionine-labeled tissues and immunofluorescent studies revealed a significant decrease of PGs in metanephric tissues, while type IV collagen and laminin were relatively unaffected. Significant glomerular changes included failure in differentiation of the visceral epithelial foot processes, formation of villi and in maturation of glomerular basement membrane. The latter was seen as fragments of extracellular matrices interspersed among undifferentiated podocytes and had reduced staining with ruthenium red--a dye marker for the PGs. This deficiency of PGs was confirmed by electron microscopic autoradiography, where a reduction in the number of silver grains was observed. The fact that the PAN-induced cellular and extracellular alterations were associated with perturbances in biosynthesis of PGs, suggests that the morphogenetic regulators, that is, PGs play a vital role in various differentiation processes involved during metanephric development.


Subject(s)
Fetus/anatomy & histology , Kidney/embryology , Puromycin/pharmacology , Animals , Autoradiography , Fetus/metabolism , Histocytochemistry , Immunohistochemistry , Kidney/metabolism , Kidney/ultrastructure , Leucine/metabolism , Methionine/metabolism , Mice , Mice, Inbred Strains , Microscopy, Electron
18.
Proc Natl Acad Sci U S A ; 94(13): 6758-63, 1997 Jun 24.
Article in English | MEDLINE | ID: mdl-9192638

ABSTRACT

The insulin family of peptides and their receptors influence cellular growth in very early preimplantation embryos. In this study their expression and role in renal organogenesis was investigated. By immunofluorescence microscopy and in situ hybridization, insulin receptor (IR) expression was seen in the ureteric bud branches and early nephron precursors in mouse metanephroi harvested at day 13 of gestation. The expression gradually decreased in successive stages of gestation, and it was confined mainly to renal tubules in 1-week-old mice. Similar developmental regulation of the IR and insulin was observed by reverse transcriptase-polymerase chain reaction (RT-PCR) analyses. Addition of insulin into the culture medium at low concentrations, ranging from 40 to 400 ng/ml, induced trophic changes and increased [3H]thymidine incorporation in the embryonic renal explants, and inclusion of IR beta-subunit-specific antisense oligodeoxynucleotide caused marked dysmorphogenesis and growth retardation of the metanephroi. Specificity of the antisense effect was reflected by immunoprecipitation experiments in which translational blockade of the beta subunit of the IR was observed. RT-PCR analyses revealed that the alpha subunit of the IR was unaffected by the antisense treatment of metanephric explants. Concomitantly, de novo synthesis of morphogenetic regulatory extracellular matrix proteins, especially the proteoglycans, was decreased. Gel-shift analyses indicated a failure in the activation of c-fos promoter region binding protein(s) by insulin in the antisense oligodeoxynucleotide-treated explants. These studies suggest that insulin and its putative receptor are developmentally regulated in the murine embryonic metanephros, and they play a role in renal organogenesis, possibly by affecting other modulators of morphogenesis-i.e., extracellular matrix proteins and protooncogenes.


Subject(s)
Gene Expression Regulation, Developmental , Insulin/biosynthesis , Kidney , Receptor, Insulin/biosynthesis , Animals , Female , Fluorescent Antibody Technique, Indirect , Insulin/genetics , Kidney/embryology , Kidney/growth & development , Kidney/metabolism , Male , Mice , Mice, Inbred ICR , Polymerase Chain Reaction , Receptor, Insulin/genetics
19.
Kidney Int ; 60(6): 2129-41, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11737587

ABSTRACT

BACKGROUND: Diabetic nephropathy accounts for over 30% of the end-stage renal disease (ESRD). A number of defined mechanisms and molecules that are involved in its pathogenesis are known, while others remain to be identified. METHODS: Suppression subtraction hybridization (SSH)-polymerase chain reaction (PCR) was employed to search for new genes that may be relevant to the pathogenesis of diabetic nephropathy during embryonic development, the time when the kidney is most susceptible to various forms of stress. A diabetic state was induced in pregnant mice at day-13 of gestation by administration of streptozotocin. The kidneys of newborn mice with blood glucose level> 200 mg/dL were harvested, mRNA isolated and subjected to SSH-PCR. Several differentially expressed cDNA fragments with up-regulated expression were isolated. One of the cDNA fragments had homology with human Ras-like guanine 5'-triphosphate (GTPase), Rap1b gene. By utilizing the lambdaZAP II mouse cDNA library and SMART RACE amplification, a full-length Rap1b cDNA was isolated. A recombinant protein was generated in pET15b bacterial expression system. An anti-Rap1b antibody was raised in rabbits by immunizing them with the fusion protein, and its specificity was confirmed by Western blot analysis. RESULTS: Rap1b cDNA had an open reading frame of 552 bp with a predicted putative protein size of approximately 21 kD. In vitro translation verified the authentication of the Rap1b cDNA clone. Northern blot analyses revealed a single approximately 2.3 kb Rap1b mRNA transcript. Its expression was up-regulated in several tissues, including the kidney of newborn diabetic mice. The degree of up-regulation of Rap1b mRNA expression was proportional to the blood glucose levels. Western blot analyses confirmed the hyperglycemia-induced up-regulation of the Rap1b expression. In situ hybridization and immunofluorescence studies revealed that Rap1b was expressed in the inner medullary collecting tubules. During hyperglycemia, its expression was accentuated and extended into the outer medullary and cortical collecting tubules. Similar up-regulation of Rap1b was observed when embryonic kidneys, harvested at day-13 of gestation, were exposed to high glucose ambience. CONCLUSION: The data suggest that Rap1b, a GTP-binding protein that plays a critical role in various signaling intracellular events, is another molecule that may be relevant to the pathobiology of diabetic nephropathy.


Subject(s)
rap GTP-Binding Proteins/metabolism , Amino Acid Sequence/genetics , Animals , Animals, Newborn/physiology , Base Sequence/genetics , DNA, Complementary/genetics , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/physiopathology , Embryo, Mammalian/metabolism , Gene Expression , Glucose/physiology , Hyperglycemia/genetics , Hyperglycemia/metabolism , Kidney/physiopathology , Mice , Mice, Inbred ICR , Molecular Sequence Data , Nucleic Acid Hybridization/methods , Polymerase Chain Reaction , Rabbits , Subtraction Technique , Up-Regulation , rap GTP-Binding Proteins/genetics
20.
Ren Fail ; 23(3-4): 301-10, 2001.
Article in English | MEDLINE | ID: mdl-11499546

ABSTRACT

Glucose is the main source or energy for the mammalian cells and its entry is mediated via various transporters. About 7 facilitative (GULT-1 to -7) and 2 concentrative glucose transporters (SGLT-1 and -2) have been identified. The facilitative glucose transporters allow the glucose entry into the cell interior due to the concentration gradient and the latter via the Na+-dependent electrochemical gradient. They have similar structural motifs with 12-14 putative transmembrane domains with a predicted protein size varying from 50 to 76kDa. Some of the facilitative glucose transporters (GLUT-1, -2, -4 and -5) and both the sodium glucose co-transporters (SGLT-1 and -2) are expressed in the kidney. The transporters that are involved in the major transport of glucose in the kidney include GLUT-2 and SGLT-2. They are of high capacity and low affinity type and are expressed in the S1 segment of the proximal tubule. All the transporters expressed in the kidney are developmentally regulated. The mRNA expression of renal GLUTs is variable during the fetal and postnatal periods. On the other hand the mRNA of SGLTs increases steadily from the fetal period to maturity along with the increase in their functional activity, i.e., glucose uptake. Recent studies indicate that the SGLTs are believed to selectively regulate tubulogenesis since they are expressed in the metanephric tubules very early in the embryonic life in mammals.


Subject(s)
Kidney/embryology , Kidney/metabolism , Monosaccharide Transport Proteins/physiology , Animals , Humans , Mammals , Monosaccharide Transport Proteins/metabolism
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