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Biomedical subjects

P Puri

Publications and source records attributed to P Puri.

At least 91 records · Page 5Linked to original sources

Megaprepuce associated with vesicoureteric reflux.

OBJECTIVE: To describe 4 patients in whom megaprepuce was associated with vesicoureteric reflux (VUR). PATIENTS AND METHODS: Four boys aged 6, 4, 5 and 7 months, respectively, presented with dribbling of urine, gross penile swelling and inability to void spontaneously. The first 3 patients had a history of documented urinary tract infection. Micturating cystourethrogram (MCUG) revealed grade III VUR on the right in the first patient, grade V on the left in the second patient, grade III on the right and grade IV in both moieties of left duplex system in the third patient and bilateral grade III in the fourth patient. All patients underwent circumcision. RESULTS: Follow-up MCUG demonstrated complete resolution of VUR in 2 patients after circumcision. One patient with bilateral VUR showed resolution of VUR on right side but persistence of VUR into the lower moiety of left duplex system after circumcision. Vesicoureteric reflux was downgraded from grade 5 to grade 3 after circumcision in one patient. CONCLUSION: These cases demonstrate for the first time the association of megaprepuce with VUR. VUR associated with megaprepuce is usually resolved after circumcision.

Circumcision, Male↗

Absence of Epstein-Barr virus in smooth muscle cells of idiopathic hypertrophic pyloric stenosis.

CONTEXT: The etiology of idiopathic hypertrophic pyloric stenosis (IHPS) is unknown. Epstein-Barr virus (EBV) infects smooth muscle cells and is associated with leiomyomas and leiomyosarcomas of immunocompromised persons, including persons with the acquired immunodeficiency syndrome. OBJECTIVE: To determine whether EBV is causally associated with IHPS. DESIGN: Biopsy samples of the pylorus were obtained from 10 infants with projectile vomiting and pyloric hypertrophy on ultrasound, with confirmation of hypertrophy at the time of pyloromyotomy. The presence of EBV infection was tested by in situ hybridization for EBV-encoded RNA 1 (EBER1) in smooth muscle cells of IHPS. SETTING: Biopsy specimens were obtained from children treated for IHPS at a tertiary referral hospital and were tested in a clinical molecular diagnostics laboratory. RESULTS: All of the 10 smooth muscle biopsies were negative for EBER1. Cellular U6 RNA was detected in all smooth muscle samples, confirming that the RNA in the specimens was intact and capable of detection by in situ hybridization. CONCLUSIONS: The absence of EBER1 in 10 cases of clinically diagnosed and histopathologically confirmed cases of IHPS effectively excludes EBV infection of smooth muscle cells as a causal factor in the pathogenesis of IHPS.

Biopsy↗

Evidence of an inflammatory pathologic condition in "normal" appendices following emergency appendectomy.

BACKGROUND: Appendices removed from patients with suspected appendicitis often appear normal on histologic examination. OBJECTIVE: To study appendix specimens for the expression of inflammatory markers as an indicator of presence of an inflammatory response in this subgroup of patients. METHODS: Cyclooxygenase 1 and 2, prostaglandin E(2), inducible nitric oxide synthase, and major histocompatibility complex class II were investigated by immunofluorohistochemistry using confocal laser microscopy in 15 acutely inflamed appendix specimens, 39 histologically classified "normal" appendices, and 11 negative control specimens. RESULTS: Strong expressions of all the inflammatory mediators were found in the mucosa of inflamed appendices, in approximately 50% of histologically normal appendices from patients with a clinical diagnosis of appendicitis, and in none of the normal control specimens. CONCLUSION: This study confirms the existence of a subgroup of appendicitis within the so-called histologically normal appendices in which evidence of an inflammatory pathologic condition is only obvious at a molecular level. The initiating signal for this and all other forms of clinical appendicitis still remains elusive.

Appendectomy↗

Three-dimensional morphology of c-Kit-positive cellular network and nitrergic innervation in the human gut.

CONTEXT: -c-Kit-positive interstitial cells of Cajal (ICC) appear to play a key role in the normal motility function and development of intestine. Nitric oxide is considered to be the most important messenger of inhibitory nonadrenergic, noncholinergic nerves in the enteric nervous system. OBJECTIVES: The aims of this study were to examine the distribution of nitrergic innervation and ICCs in normal human bowel and to demonstrate interconnections between ICCs and nitrergic nerves and smooth muscle fibers using histochemical and immunohistochemical double-staining methods with a whole-mount preparation technique and confocal laser scanning microscopy. METHODS: Full-thickness small and large bowel specimens were obtained at autopsy from 18 children who died of nongastrointestinal diseases. A whole-mount preparation was performed for all specimens, and double staining was carried out with nicotinamide adenine dinucleotide phosphate (reduced form, NADPH)-diaphorase and c-Kit immunohistochemistry. Double immunofluorohistochemistry with neuronal nitric oxide synthase and c-Kit using confocal laser scanning microscopy was also performed in all specimens. RESULTS: The whole-mount preparation facilitated 3-dimensional visualization of the meshlike network of NADPH-diaphorase-positive nerve fibers in the myenteric plexus surrounded by a reticular network of c-Kit-positive ICCs. The dense c-Kit-positive cellular network located between longitudinal and circular muscle layers and at the innermost part of circular muscle layer intermingled with the myenteric plexus. Short, fine processes of ICCs made connections with the muscle fibers and c-Kit-positive cells. CONCLUSIONS: The development of double-NADPH-diaphorase histochemistry and c-Kit immunohistochemistry staining technique in a whole-mount preparation provides an easy and useful method for investigating the association between c-Kit-positive cellular network and nitrergic neuronal network in the human bowel wall. The characteristic profiles of the c-Kit-positive cellular network and nitrergic neuronal network and their relationship with the smooth muscle fibers provide a morphologic basis for investigating intestinal motility disorders.

Fluorescent Antibody Technique↗

Demonstration of neuronal networks in the human upper urinary tract using confocal laser scanning microscopy.

PURPOSE: To our knowledge innervation of the upper urinary tract and its role in motility and sensation are not clearly understood. The whole mount preparation technique provides 3-dimensional (D) morphology of the innervation and its relationship of branching and interconnecting nerve fibers to each other and to the neighboring tissues. Confocal laser scanning microscopy provides dramatic optical advantages for detecting 3-D structures in thick specimens. We investigated the distribution and morphology of the neuronal structures in the human upper urinary tract using the whole mount preparation technique and confocal laser scanning microscopy. MATERIALS AND METHODS: Whole mount preparations of the human renal pelvis and ureter were stained by standard immunohistochemical method using various neuronal markers (protein gene product 9.5, neuron specific enolase and neurofilament). The 3-D architecture of the specimens was investigated with the help of confocal laser scanning microscopy. RESULTS: We detected 2 mesh-like neuronal networks or plexus in the human upper urinary tract. The first and more prominent plexus was located in the submucosa between the lamina propria and tunica muscularis, and the second neuronal network was found between the smooth muscle fibers of the ureteral wall. There were frequent interconnections between the 2 networks in the ureteral wall. CONCLUSIONS: To our knowledge our study shows for the first time that there are 2 well formed mesh-like neuronal plexus in the human upper urinary tract. Our findings suggest that the autonomic nervous system of the human upper urinary tract may have a significant role in the propagation, coordination and modulation of ureteropelvic peristalsis.

Adolescent↗

[Increase of the chondroitin-sulfate proteoglycan, fibronectin and fibroblasts in infantile hypertrophic pyloric stenosis].

INTRODUCTION: Infantile hypertrophic pyloric stenosis (IHPS) consists of hypertrophy of the muscular layer of the pylorus. Its etiology is still unknown. In the last years only few jobs that studied the extracellular matrix (ECM) in the muscular layer in the IHPS have been reported. Our aim was to investigate the expression of two ECM molecules: chondroitin-sulfate proteoglycan (CSPG) and fibronectin (FN), and fibroblasts. MATERIAL AND METHODS: Full-thickness muscle biopsy specimens were obtained from 33 IHPS patients at pyloromyotomy and 12 controls. Indirect immunohistochemistry was performed using CSPG, FN and fibroblasts monoclonal antibodies. The results were showed by a semiquantitative scale as follows: strong (++), moderate (+), weak (+/-), and absent (-). RESULTS: We demonstrated that the CSPG immunoreactivity was localized in the connective tissue septa and the expression of FN molecules in the pericellular space. Both molecules were significantly the increased in the muscle layer of the pylorus with IHPS in relation to control pylorus. We also demonstrated a marked increased expression in the number of fibroblasts in the muscle layer of the pylorus with IHPS. Even-though the most striking increase was localized in the septa, we also observed great number of fibroblasts amongst the smooth muscle cells. CONCLUSIONS: We suggest that IHPS is characterized, not only by the muscle layer hypertrophy, but also by the increase of several ECM molecules, such as CSPG and FN. We also think that the increase of fibroblast could explain the higher expression of both ECM molecules in the muscle layer of pylorus in IHPS.

Chondroitinases and Chondroitin Lyases↗

UltraRapid communication : nuclear factor-kappaB and cAMP response element binding protein mediate opposite transcriptional effects on the flk-1/KDR gene promoter

-The vascular endothelial growth factor receptor Flk-1/KDR is highly expressed during development and almost disappears in adult tissues. Despite its biological relevance, little is known about the molecular mechanisms controlling its expression. In the present work, it is shown that cAMP response element binding protein (CREB) and nuclear factor-kappaB (NF-kappaB)-related antigens bind specific sequences in the Flk-1/KDR promoter. Functional studies demonstrate that cAMP represses whereas tumor necrosis factor-alpha, an activator of NF-kappaB, stimulates promoter activity. Histone acetyltransferases (HATs) P/CAF and CBP/p300 together with p65/RelA, the catalytic subunit of NF-kappaB, increase Flk-1/KDR promoter activity 10- to 20-fold. Consistently, inhibition by cAMP is reverted by increasing intracellular HATs and is completely abolished by site-specific mutagenesis of the cAMP response element. In contrast, specific mutations in the NF-kappaB response element abolish responsiveness to p65/RelA and HATs without affecting cAMP-dependent repression. These results suggest that opposing signaling pathways, activating NF-kappaB or CREB and requiring HAT molecules, control Flk-1/KDR promoter activity. texfThe full text of this article is available at http://www.circresaha.org. Key Words: vascular endothelial growth factor receptor promoter nuclear factor-kappaB transcription angiogenesis Web Site Feature

Journal Article↗

Nuclear factor-kappaB and cAMP response element binding protein mediate opposite transcriptional effects on the Flk-1/KDR gene promoter.

-The vascular endothelial growth factor receptor Flk-1/KDR is highly expressed during development and almost disappears in adult tissues. Despite its biological relevance, little is known about the molecular mechanisms controlling its expression. In the present work, it is shown that cAMP response element binding protein (CREB) and nuclear factor-kappaB (NF-kappaB)-related antigens bind specific sequences in the Flk-1/KDR promoter. Functional studies demonstrate that cAMP represses whereas tumor necrosis factor-alpha, an activator of NF-kappaB, stimulates promoter activity. Histone acetyltransferases (HATs) P/CAF and CBP/p300 together with p65/RelA, the catalytic subunit of NF-kappaB, increase Flk-1/KDR promoter activity 10- to 20-fold. Consistently, inhibition by cAMP is reverted by increasing intracellular HATs and is completely abolished by site-specific mutagenesis of the cAMP response element. In contrast, specific mutations in the NF-kappaB response element abolish responsiveness to p65/RelA and HATs without affecting cAMP-dependent repression. These results suggest that opposing signaling pathways, activating NF-kappaB or CREB and requiring HAT molecules, control Flk-1/KDR promoter activity.

Acetyltransferases↗

Effect of hyperoxia on surfactant protein gene expression in hypoplastic lung in nitrofen-induced diaphragmatic hernia in rats.

The hypoplastic lung in congenital diaphragmatic hernia (CDH) has both a quantitative and qualitative reduction in surfactant. Recently, the role of oxygen (O2) as a regulator of pulmonary surfactant-associated protein (SP) gene expression has been reported. The mRNA level of SP has been demonstrated to be increased in the lungs of animals exposed to hyperoxia. The aim of this study was to investigate SP mRNA expression in hypoplastic CDH lung in rats during mechanical ventilation in order to determine the effect of O2 on SP synthesis in CDH. A CDH model was induced in pregnant rats following administration of nitrofen. The newborn rats with CDH and controls were intubated and ventilated. Ventilation was continued for 6 h under 100% oxygen. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to evaluate the relative amounts of mRNA expression of SP-A, SP-B, SP-C, and SP-D. Relative amounts of SP-A, SP-B, and SP-D mRNA expression in CDH lung were significantly decreased compared to controls at birth and 6 h after ventilation. There was no significant difference in SP-C mRNA expression between CDH animals and controls. Upregulated mRNA expression of SP-A, SP-B, and SP-D in lungs of control animals at 6 h after ventilation suggests that oxygenation accelerates postnatal SP synthesis in normal lungs. The inability of O2 to increase SP mRNA expression in hypoplastic CDH lung suggests that the hypoplastic lung is not responsive to increased oxygenation for the synthesis of SP.

Abnormalities, Drug-Induced↗

The hypoplastic heart in congenital diaphragmatic hernia: reduced expression of basic fibroblast growth factor and platelet-derived growth factor.

Newborn infants with congenital diaphragmatic hernia (CDH) still have high mortality. Recently, the possible role of a cardiac maldevelopment in the high mortality has been suggested. Human and animal studies have demonstrated that heart weight is significantly reduced in the presence of CDH. Basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) are pleiotropic regulatory peptides that are expressed in myocardium in precise developmental and spatial programs. PDGF and bFGF both stimulate cardiac growth by inducing cell proliferation and stimulating the synthesis of extracellular matrix. The aim of this study was to investigate the presence of heart hypoplasia in nitrofen-induced CDH in rats and the role of specific tissue growth factors (bFGF and PDGF) in its genesis. CDH was induced in pregnant rats following administration of 100 mg nitrofen on day 9.5 of gestation (term 22 days). In control animals the same dose of olive oil was given without nitrofen. Cesarean section was performed on day 21 of gestation. The fetuses were divided in two groups: normal controls (n = 8) and nitrofen-induced CDH (n = 8). Total RNA, DNA, and soluble proteins were extracted from the heart in each group and measured. mRNA was extracted from total RNA and a reverse transcription-polymerase chain reaction (RT-PCR) was performed to evaluate mRNA expression of bFGF and PDGF. The heart/body weight ratio (HBWR) and DNA content were significantly decreased (P < 0.01) in CDH animals compared to controls. RNA and protein content were also reduced in CDH. The expression of bFGF and PDGF mRNA was significantly reduced in the CDH group compared to controls (P < 0.01). The decreased HBWR, DNA, RNA, and protein content in the CDH heart indicates that the heart is hypoplastic in nitrofen-induced left CDH. The downregulation of bFGF and PDGF gene expression in the CDH heart suggests that these regulating peptides may play an important role in the genesis of cardiac hypoplasia in CDH.

Actins↗

Antenatal dexamethasone improves atrial natriuretic peptide receptors in hypoplastic lung in nitrofen-induced diaphragmatic hernia in rats.

Atrial natriuretic peptide (ANP) plays a major role in electrolyte and volume homeostasis through potent biological effects including vasorelaxation, bronchorelaxation, lung permeability, and clearance. There are two distinct biochemical and functional classes of ANP receptors, guanylate cyclase receptor (GC-R) and clearance receptors (clearance-R). Two subtypes of GC-R have been described, GCA-R and GCB-R. Antenatal glucocorticoid therapy (AGT) has been demonstrated to improve pulmonary immaturity and abnormal structure of pulmonary arteries in animal models of congenital diaphragmatic hernia (CDH). The aim of this study was to investigate the effect of antenatal glucocorticoid administration on the ANP system in nitrofen-induced CDH hypoplastic lung in rats. A CDH model was induced in pregnant rats following administration of nitrofen on day 9.5 of gestation. Dexamethasone (Dex) was given intraperitoneally on days 18.5 and 19.5; cesarean section was performed on day 21. Reverse transcription polymerase chain reaction was performed to evaluate the relative amounts of GCA-R, GCB-R and clearance-R mRNA expression. The mRNA expression of GCA-R, GCB-R, and clearance-R was significantly increased in CDH compared to control lung. ANP receptor mRNA expression was significantly decreased in CDH lung with compared to without Dex treatment. Our finding of increased ANP receptor mRNA expression in CDH lung suggests that the hypoplastic lung has high sensitivity for ANP. Decreased mRNA expression of ANP receptors in CDH lung after Dex treatment suggests that AGT may improve pulmonary physiological function of ANP in hypoplastic CDH lung.

Animals↗

Muscarinic acetylcholine receptor expression in aganglionic bowel.

In Hirschsprung's disease (HD) there exists an overabundance of acetylcholine (ACh), which in turn stimulates excessive production of the enzyme acetylcholinesterase. Muscarinic ACh receptors (mAChRs) play an important role in smooth-muscle contraction. Recent studies have indicated five different subtypes of mAChRs encoded by five different genes, ml to m5. The purpose of this study was to investigate the expression of each mAChR subtype in aganglionic (AG) colon to further understand the pathophysiology of HD. Entire colon resected at the time of pull-through operation for HD was obtained from 14 patients. Specimens obtained at autopsy from 8 age-matched patients without gastrointestinal disease acted as controls. Frozen sections were used for indirect immunohistochemistry as well as in-situ hybridization. Immunohistochemistry was performed using specific antiserum against each mAChR subtype and in-situ hybridization was performed using specific oligonucleotide probes against ml to m5 subtypes. Messenger RNA (mRNA) was extracted from normoganglionic (NG) and AG bowel of HD patients and normal control bowel. Reverse transcription-polymerase chain reaction was performed to evaluate mRNA levels of each mAChR subtype. To adjust the levels of mRNA expression, a housekeeping gene G3PDH, known to be expressed normally, was used as an internal control. Strong m2 and m3 immunoreactivity was observed in the mucosal layer, smooth-muscle layers, and myenteric plexus of NG bowel, whereas ml immunoreactivity was only detected in the mucosal layer. The most striking finding was the abundance of m3-immunoreactive fibers in muscle layers of NG bowel while there was a total lack of m3 fibers in smooth-muscle of AG bowel. Intense mRNA signals encoding m2 and m3 and to a lesser degree ml were detected in NG bowel, and these signals were weak in AG bowel. Immunoreactivity and mRNA expression of m4 and m5 was not detected in NG or AG bowel. The lack of m3-immunoreactive fibers in the smooth-muscle layers of AG bowel and decreased m2 and m3 mRNA expression in AG bowel may be responsible for the motility dysfunction in the aganglionic segment.

Child↗

The innervation of human bowel mucosa and its alterations in Hirschsprung's disease using a whole-mount preparation technique.

The innervation of the human bowel wall and its structural and functional changes in Hirschsprung's disease (HD) are well-recognised. The luminal surface of the bowel acts as a multifunctional barrier, and modifications in its physiochemical properties can result in serious complications such as enterocolitis (EC). The whole-mount preparation (WMP) technique produces a three-dimensional (3D) picture to better demonstrate the neuronal networks and the relationship of branching and interconnecting nerve fibres to each other. The aim of this study was to investigate the innervation of the mucosal layer in normal and HD bowel using a WMP immunohistochemistry technique in order to better understand the pathophysiology of HD. Full-thickness bowel specimens were collected from 9 HD patients at pull-through operation. Normal control small- and large-bowel specimens were collected from 10 patients at the time of bladder augmentation. Suction rectal biopsies from 8 patients with chronic constipation and 2 patients with HD were also included in this study. A WMP of the mucosal layer was made and stained with various neuronal markers (S100, PGP 9.5, and LICAM) using fluorescein immunohistochemistry. PGP 9.5, S100, and L1CAM immunofluorescence staining of the normal mucosa demonstrated a characteristic 3D meshlike neuronal network of uniform thickness surrounding the crypts. In the aganglionic bowel S100, PGP 9.5, and L1CAM-positive meshlike networks were replaced by thick nerve trunks in the muscosa without any interconnecting network. The present study demonstrates for the first time the 3D morphology of mucosal innervation in normal and aganglionic bowel. The WMP technique clearly demonstrated that the mucosal innervation in HD is morphologically abnormal, and this may adversely influence secretory and absorptive functions of the bowel. WMPs using suction rectal biopsy specimens may be a useful additional technique to diagnose HD.

Antigens, Differentiation↗

Structural immaturity of the pylorus muscle in infantile hypertrophic pyloric stenosis.

Recent reports indicate that extracellular matrix and cytoskeleton plasmalemmal elements are altered in infantile hypertrophic pyloric stenosis (IHPS). Desmin is a cytoskeletal protein that is important for the organization and function of muscular fibers. It has been found to be increased in the smooth muscle in chronic intestinal pseudo-obstruction and in skeletal muscle in some forms of myopathies as well as in unexplained hypertrophic cardiomyopathies. The aim of this study was to analyze the expression of desmin in IHPS. Full-thickness muscle-biopsy specimens were obtained from 8 IHPS patients (age range 23 to 41 days) at pyloromyotomy, from 8 age-matched controls without evidence of gastrointestinal (GI) disease at autopsy, and from 2 stillborns who died at 27 and 30 weeks of gestation without evidence of GI disease. Indirect immunohistochemistry was performed using the avidin-biotin-peroxidase complex method with anti-desmin and visualized by development with 3-diaminobenzidine tetrahydrochloride. Pyloric muscle in IHPS demonstrated strong desmin immunoreactivity. The expression of desmin was also strong in the muscular layers of fetal pylorus. In the age-matched controls absent or weak desmin immunoreactivity was seen in the pyloric muscle layer. The increased amount of desmin in hypertrophied pyloric muscle in IHPS may result in inco-ordination of contraction and relaxation of the pylorus, thus causing motility dysfunction. The similar pattern of desmin expression in IHPS and fetal pylorus suggests that the organization of intermediate filaments in IHPS is in a fetal stage of development.

Desmin↗

Increased expression of fibroblast growth factors in segmental renal dysplasia.

Renal dysplasia (RD) is a disorganized development of renal parenchyma that results in a deficit of functional renal tissue. Dysplastic renal tissue is characterized by primitive tubular epithelium associated with increased mesenchyme. Several polypeptide growth factors (GF), which interact with target cells through a cell-surface membrane receptor, have been reported to be involved in the regulation of urothelial cell growth in normal and neoplastic states. Recent reports have demonstrated that basic fibroblast GF (bFGF, FGF-2) is a mitogen for renal proximal-tubule epithelial cells. Keratinocyte GF (KGF, FGF-7), which belongs to the FGF family, is believed to be a paracrine mediator of epithelial-cell proliferation. The aim of this study was to investigate the immunoactivity of bFGF and KGF and their receptors in the dysplastic kidney in order to further understand the pathogenesis of RD. Specimens of dysplastic upper poles of duplex kidneys were surgically resected from ten patients. Age-matched control material included six kidney specimens taken at autopsy from patients without evidence of urologic disease. Indirect immunohistochemistry was performed using the Strept-ABC method with four antibodies: bFGF, KGF, FGF receptor (flg), and KGF receptor (bek). There was absent or weak bFGF, KGF, flg, and bek immunoreactivity in normal kidneys. In the dysplastic kidneys, there was strong immunoreactivity of bFGF and KGF and their receptors in the epithelium of primitive tubules. Increased local expression of bFGF and KGF and their receptors in primitive tubules suggests that bFGF and KGF may play an important role in the development of RD.

Child↗