Biomedical subjects
Publications and source records attributed to H Shima.
We present a case of low-flow priapism that was successfully treated. A 21-year-old man with a history of schizophrenia was admitted with a painful complete erection. He had taken propericiazine, phenothiazine derivatives, before hospitalization and was treated with a glandular-cavernosal shunt (El-Ghorab's procedure). Currently, he is able to have erections without any changes in his quality of life.
PURPOSE: The form and function of the heart are the final result of an integration of cells, tissues, and extracellular material. The extracellular matrix (ECM) is a complex array of different molecular components, and it plays an important role for the transfer of mechanical force in both contraction and relaxation phases in the cardiac cycle. ECM plays also a significant role in the development of the heart. The aim of this study was to evaluate the expression of important ECM components in the heart of rats with induced CDH to test the hypothesis that an alteration of ECM may contribute to the cardiac maldevelopment, which recently has been identified as a contributive factor for the high mortality rate in babies with congenital diaphragmatic hernia (CDH). METHODS: CDH model was induced in pregnant rats after administration of 100 mg of 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 into 2 groups: normal control (n = 10) and nitrofen-induced CDH (n = 10). Reverse transcription polymerase chain reaction (RT-PCR) was performed to evaluate the relative amount of tropoelastin and alpha1 (I) procollagen mRNA expression. Elastin protein content was measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: There was a reduction in tropoelastin mRNA (P <.05) and procollagen mRNA (P <.05) in CDH compared with controls. The cardiac alpha-elastin content also was reduced in CDH (P <.01). CONCLUSIONS: The reduced cardiac tropoelastin and procollagen gene expression and the reduced alpha-elastin content indicate that the heart in CDH structurally is immature. The reduced production of cardiac ECM may contribute to a contractile dysfunction, which makes the heart unable to respond to the hemodynamic load accompanying persistent pulmonary hypertension (PPH).
BACKGROUND/PURPOSE: Increasing evidence suggests that the enteric nervous system is under the control of neurotrophins. Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5), promote differentiation, growth, and survival of various central and peripheral nervous system neurons. The biological effects of neurotrophins are mediated by the interactions with high-affinity tyrosine kinase receptors (TrkA, TrkB, TrkC). Recently, abnormalities of intramuscular innervation have been reported in infantile hypertrophic pyloric stenosis (IHPS). To further understand the reported abnormalities in pyloric innervation in IHPS, the authors analyzed the expression of Trk receptors and the neurotrophins content in IHPS. METHODS: Full-thickness muscle biopsy specimens were obtained from 8 IHPS patients (age range, 23 to 41 days) at pyloromyotomy and from 8 age-matched controls without gastrointestinal disease at autopsy performed within 12 hours after death. Indirect immunohistochemistry was performed using ABC (Avidin Biotin peroxidase Complex) method with anti-Trk specific antibodies (A,B,C). Quantitative analysis was performed using sandwich-type ELISA for NGF, BDNF, NT-3, and NT-4/5. RESULTS: The intensity of staining of the myenteric plexus for TrkA, TrkB, and TrkC was similar among IHPS and controls. There was a lack of TrkA-positive nerve fibers in IHPS compared with controls. The quantity of total NGF, NT-3, and BDNF in IHPS was significantly lower than in controls. CONCLUSIONS: The reduced production of neurotrophins in IHPS may be responsible for the delay in the functional and structural maturation of pyloric innervation in IHPS. The lack of TrkA-positive nerve fibers in pyloric muscle may explain the abnormal intramuscular innervation in IHPS.
BACKGROUND/PURPOSE: The aim of this study was to determine the gene and protein levels of atrial natriuretic peptide (ANP) in the heart of nitrofen-induced congenital diaphragmatic hernia (CDH) in rats and to evaluate the effect of antenatal dexamethazone (Dex) treatment. METHODS: CDH model was induced in pregnant rats after administration of 100 mg of nitrofen on day 9.5 of gestation (term, day 22). Dexamethazone (Dex, 0.25 mg/kg) was given by intraperitoneal injection on days 18.5 and 19.5 of gestation. Cesarean section was performed on day 21 of gestation. The fetuses were divided into 3 groups: group I, control (n = 10); group II, nitrofen-induced CDH (n = 10); group III, nitrofen-induced CDH with antenatal Dex treatment (n = 10). ANP protein was measured using enzyme-linked immunosorbent assay (ELISA) technique. Reverse transcription polymerase chain reaction (RT-PCR) was performed to evaluate the relative amount of atrial natriuretic peptide (ANP) mRNA expression. RESULTS: There was a significant reduction in ANP mRNA (P <.05) and protein (P <.01) levels in heart of group II (CDH) compared with group I. Antenatal Dex treatment significantly increased both ANP mRNA and protein levels in the heart of CDH animals (P <.05). CONCLUSIONS: The reduced cardiac ANP gene expression and ANP synthesis indicates that the heart in CDH is functionally immature and may be unable to respond to hemodynamic load accompanying persistent pulmonary hypertension (PPH). ANP or drugs such as steroids, which raise endogenous ANP levels, may have a therapeutic application in CDH complicated by PPH.
PURPOSE: We reviewed 54 pediatric patients with ectopic ureter treated at our institution from 1975 to 1999. MATERIALS AND METHODS: Our series comprised 40 female and 14 male children, with age from 1 month to 11 years. Clinical records of the patients were reviewed retrospectively. RESULTS: Chief complaint was urinary incontinence in 24, high fever in 18, abdominal mass in 6, scrotal swelling in 3 and growth retardation in 2 patients. Two patients were found to have ectopic ureters without symptom during urological work-ups for their anorectal anomaly. The ectopic ureters opened into vagina in 19, vestibulum in 8, bladder neck in 7, urethra in 17, seminal vesicle in 2 and ejaculatory duct in 1 patient (s). Treatment was ureterocystoneostomy in 30, nephroureterectomy in 19, hemi-nephroureterectomy in 2, and ureteral ligature in 1 patient (s). Postoperatively, most of the patients became symptom free except for 6 patients in whom urinary incontinence was not cured due to mal-development of the bladder neck and sphincter, and due to Gartner's duct cyst. CONCLUSION: Urinary incontinence and urinary tract infection are most frequent presentations of ectopic ureter in children. Although most of the patients are cured with ureterocystoneostomy or nephroureterectomy, some incontinent girls continue to have urinary incontinence due to mal-development of the bladder neck and sphincter or Gartner's duct cyst.
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I-2(PP2A)/SET, an inhibitor of protein phosphatase 2A, is supposed to be one of the oncoproteins associated with human myeloid leukemia. The I-2(PP2A)/SET gene expression was observed ubiquitously among all the rat tissues examined, but low in liver. Of interest is that the expression in the rat primary hepatomas and hyperplastic nodules was significantly elevated. The experiments using regenerating livers after partial hepatectomy showed that the expression of I-2(PP2A)/SET mRNA was low at the quiescent hepatocytes, but up-regulated at 12-24 h after partial hepatectomy, which corresponds to the mid G1 to S transition in the cell cycle. These results suggested the importance of I-2(PP2A)/SET in the hepatocarcinogenesis and hepatic cell proliferation.
We have isolated human cDNA for a novel type 1 protein phosphatase (PP1) inhibitory protein, named inhibitor-4 (I-4), from a cDNA library of germ cell tumors. I-4, composed of 202 amino acids, is 44% identical to a PP1 inhibitor, inhibitor-2 (I-2). I-4 conserves functionally important structure of I-2 and exhibited similar biochemical properties. I-4 inhibited activity of the catalytic subunit of PP1 (PP1C), specifically with an IC(50) of 0.2 nM, more potently than I-2 with an IC(50) of 2 nM. I-4 weakly inhibited the activity of myosin-associated phosphates (PP1M). However, the level of inhibition of PP1M was increased during preincubation of PP1M with I-4, suggesting that the inhibition is caused by interaction of I-4 with PP1C in such a manner that it competes with the M subunit of PP1M. Gel overlay experiments showed that I-4 binds PP1C directly. Three I-4 peptides containing the N-terminal residues 1-123, 1-131, and 1-142 all showed strong binding ability to PP1C but did not show PP1 inhibitory activity, whereas an I-2 peptide (residues 1-134), lacking the corresponding C-terminal residues, potently inhibited PP1C activity as previously reported. Removal of the 18 N-terminal amino acid residues from I-4 dramatically reduced the PP1 binding activity with a correlated loss of inhibitory activity, whereas removal of the 10 N-terminal residues had only a little effect. The two peptides GST-I-4(19-131) and GST-I-4(132-202) showed ability to bind to PP1C, albeit very weakly. These results strongly suggest a multiple-point interaction between I-4 and PP1C, which is thought to cause the inhibition of I-4 which is stronger than the inhibition of I-2.
We engineered and expressed both a wild-type and mutant cytosolic isoform of PTPepsilon (PTPepsilonC) in murine M1 leukemic cells, which can be induced to growth arrest and monocytic differentiation by interleukin (IL)-6 and leukemia inhibitory factor (LIF). Forced expression of PTPepsilonC inhibited IL-6- and LIF-induced monocytic differentiation and apoptosis in M1 cells, whereas expression of PTPepsilonM, a transmembrane isoform of PTPepsilon, did not. PTPepsilonC expression resulted in lower levels of IL-6-induced tyrosine phosphorylation of Jak1, Tyk2, gp130, and Stat3 compared with parent cells. In M1 transfectants expressing an inactive mutant of PTPepsilonC, both tyrosine phosphorylation and apoptosis induced by IL-6 and LIF were potentiated rather than inhibited. These results suggest an important role for PTPepsilonC in negative regulation of IL-6- and LIF-induced Jak-STAT signaling.
Two cDNAs sequences (1320 bp and 1180 bp) of the 55-kDa subunit associated with a testis-specific serine/threonine protein phosphatase 1gamma2 (PP1gamma2) were cloned. They were the same up to 1180 bp, suggesting that they may be generated by alternative splicing. Sequence studies showed that the 1320 bp-cDNA is a homolog of the human sds22alpha(1) (thus, named rat sds22alpha(1)). The 1180 bp-cDNA is a new splice-variant since its sequence at the 3' end has not been identified in human sds22 genes (named rat sds22alpha(3)). The 1320 bp-cDNA is ubiquitously expressed in various tissues including the immature testis. However, the expression of 1180 bp-cDNA was only observed in the testis after puberty. This expression pattern matches very well with that of PP1gamma2, suggesting that 1180 bp-cDNA may encode the 55-kDa subunit to associate with PP1gamma2 in rat testis and is involved in spermatogenesis by controlling PP1gamma2 activity.
Despite the physiological importance of serine/threonine protein phosphatase type 2B (PP2B/calcineurin), an accurate assay method of PP2B in crude tissue extracts has not been established. By using recombinant protein phosphatase inhibitor-1 as a substrate and ascorbic acid as an antioxidant, we developed an improved assay method for PP2B activity in crude extracts from mouse tissues and investigated tissue distribution of its activity. Under the assay conditions, the PP2B activities were stable for at least 30 min with more than 100-fold higher sensitivity than those previously reported. The specific activities of PP2B were 22.3, 0.85, 2.9, 0.36, and 1.5 mU/mg protein in mouse brain, heart, spleen, liver, and testis, respectively, and furthermore in each region of the brain they were 26.1, 13.7, 42.8, 40.5, 15.1, and 8.6 mU/mg protein in cerebrum, midbrain plus interbrain, striatum, hippocampus, cerebellum, and brain stem, respectively. This is the first paper to demonstrate a close correlation between tissue distributions and content of PP2B. These results showed that the present assay method is extremely powerful for precise measurement of a wide range of PP2B activities including not only high PP2B activity in the brain but also low PP2B activities in other tissues.
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.
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.
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.
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.
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.
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.
The aim of this study was to investigate the effect of antenatal glucocorticoid therapy on smooth-muscle-cell (SMC) DNA synthesis in the pulmonary arteries (PA) in a nitrofen-induced congenital diaphragmatic hernia (CDH) rat model following nitrofen administration on day 9.5 of gestation. Antenatal dexamethasone (DEX) was given intraperitoneally on days 18.5 and 19.5 of gestation. Bromodeoxyuridine (BrdU) was injected via a jugular vein into the dam 1 h before the fetuses were killed by cesarean section at term. The fetuses were divided into three groups: group I (n = 10): normal controls; group II (n = 10): nitrofen-induced CDH; group III (n = 10): nitrofen-induced CDH with antenatal DEX treatment. Immunostaining of the lungs with anti-BrdU antibody was obtained by a standard avidin-biotin complex method. The number of immunopositive cells in the PA media and adventitia were counted using an image analyzer and analyzed statistically. The number of BrdU-immunopositive cells in the media was significantly increased in group II (16.83 +/- 3.01) compared to groups I (9.16 +/- 2.20) and III (6.83 +/- 1.70) (P < 0.01). There was no significant difference between groups I and III. The number of BrdU-immunopositive cells in the adventitia was not significantly different between the three groups. Antenatal DEX treatment inhibits SMC DNA synthesis in PA media in CDH lungs. This may be a possible mechanism by which antenatal DEX prevents structural PA changes in nitrofen-induced CDH in rats.