Biomedical subjects

Y Kitano

Publications and source records attributed to Y Kitano.

At least 55 records · Page 3Linked to original sources

PubMed1999

Influence of increased abdominal pressure on steady-state cardiac performance.

The effect of steady-state increases in abdominal pressure (Pab) on cardiac performance was studied in seven acutely instrumented swine with pneumoperitoneum (PP). The animal was placed on volume-preset ventilation, and PP was created by air insufflation. Cardiac output (CO), right atrial (Pra), left atrial (Pla), pericardial (Ppe), and abdominal inferior vena cava pressures (Pivc) were measured while Pab was increased from baseline to 7.5, 15, and 30 mmHg (PP7.5, PP15, and PP30, respectively). Cardiac function curves of the right and left ventricle (RV and LV, respectively) were compared between baseline and PP30. CO presented biphasic changes, with an inital slight increase at PP7.5 followed by a fall at PP30. A significant discrepancy was observed between Pra and Pivc at PP15 and PP30, consistent with development of a "vascular waterfall." Transmural Pla (Pla - Ppe) showed parallel changes with CO, whereas transmural Pra (Pra - Ppe) exhibited a sustained increase. The RV cardiac-function curve was more depressed than was that of the LV at PP30; this suggests an increased RV afterload produced by the elevated airway pressure. These results support the hypothesis that our previously proposed concept of abdominal vascular zone conditions (M. Takata, R. A. Wise, and J. L. Robotham. J. Appl. Physiol. 69: 1961-1972, 1990) is also applicable to steady-state hemodynamic analyses. The abdominal zones appear to play an important role in determining CO, with increases in Pab, by modulating systemic venous return and the LV preload. Simultaneous measurements of Pra and Pivc may provide useful information in the hemodynamic care of patients with elevated Pab.

Abdomen↗

PubMed1999

Fetal tracheal occlusion in the rat model of nitrofen-induced congenital diaphragmatic hernia.

Prenatal tracheal occlusion (TO) consistently accelerates lung growth in the sheep model of congenital diaphragmatic hernia (CDH). However, significant variability in lung growth has been observed in early clinical trials of TO. We hypothesized that lung hypoplasia created at relatively late stages of lung development may not be equivalent to human CDH-induced lung hypoplasia, which begins early in gestation. To test this hypothesis, we performed TO in the rat model of nitrofen-induced CDH. Left-sided CDH was induced by administering 100 mg of nitrofen to timed pregnant rats on day 9 of gestation. On day 19 of gestation, four to five fetuses per dam underwent surgical ligation of the trachea. At death (day 21.5), lungs from non-CDH (non-CDH group), left-CDH (CDH group), and trachea-occluded left-CDH fetuses (CDH-TO group) were harvested and compared by weight, DNA and protein content, and stereological morphometry. Wet and dry lung weight-to-body weight ratio, total lung DNA and protein contents, the volume of lung parenchyma, and the total saccular surface area of the CDH-TO group were significantly increased relative to the CDH group and were either greater than or comparable to the non-CDH controls. We conclude that TO accelerates lung growth and increases lung parenchyma in an early-onset model of CDH-induced lung hypoplasia.

Animals↗

PubMed1999

Electrophysiologic parameters to predict clinical recurrence of ventricular tachycardia in patients under electrophysiologic study-guided effective pharmacological therapy.

Although an electrophysiologic study (EPS) is the most reliable method for selecting the treatment for a patient with sustained ventricular tachycardia (VT), VT recurrence may occur even during EPS-guided effective therapy. Electrophysiologic parameters were compared between patients with and without arrhythmic events under EPS-guided effective therapy to identify the predictive parameters of VT recurrence during the clinical course. The study population consisted of 77 consecutive patients with sustained VT who were receiving long-term pharmacological therapy that was demonstrated to be effective by the EPS assessment. The VT induction protocol employed 1-3 extrastimuli and rapid ventricular pacing at 2 right ventricular sites and 1 left ventricular site, and isoproterenol was infused when VT was not induced. To determine the 'effective' antiarrhythmic drug, all sustained ventricular arrhythmias had to be prevented during the whole induction protocol, but repetitive ventricular responses (RVR) were allowed to remain for up to 5 beats when they were in the same QRS configurations as the clinical VT and up to 12 beats when they were in polymorphic QRS configurations. The effective refractory periods (ERPs) at the 3 ventricular pacing sites and their difference (i.e., ERP-dispersion) and the maximum number of RVR beats were evaluated in an EPS during the control state and at the time of drug assessment. In the comparison of patients with and without VT recurrence, there was no significant difference in clinical characteristics or ERPs, but the deltaERP-dispersion (i.e., the increase in ERP-dispersion caused by the antiarrhythmic drug) and the maximum number of RVRs were significantly smaller in the group of patients without VT recurrence (deltaERP-dis, -3+/-8 vs. 6+/-12, p = 0.0027; maxRVR, 3+/-3 vs. 5+/-4, p = 0.0160). The VT recurrence rate was significantly lower in the patients with deltaERP-dis < or =0 or maxRVR<6 in comparison with the others (p = 0.01 14 and p = 0.0360). Patients with VT recurrence showed greater deltaERP-disp and a longer duration of RVRs at the time of drug assessment in comparison with the patients without VT recurrence. The prognosis of patients under EPS-guided therapy may be improved by the use of stricter criteria for drug assessment in the EPS, although this may decrease the number of drug responders determined in the EPS.

Adolescent↗

PubMed1999

Importance of retrograde atrial activation in atrial fibrillation genesis in the initiation of atrial fibrillation in Wolff-Parkinson-White syndrome. Comparison of atrial electrophysiologic parameters between patients with different atrial fibrillation genesis (initiation sites) in atria.

The changes in the duration of atrial electrograms during different atrial activation sequences from a sinus rhythm were evaluated to test the hypothesis that the prolongation of atrial electrogram duration caused by the different atrial activation sequence is more prominent at the site of atrial fibrillation (Afib) genesis (initiation site) than other areas. In 39 patients with single retrograde left-sided accessory connection who had inducible transient atrial fibrillation during an electrophysiologic study, the site of Afib genesis was determined and classified into three groups, i.e., 1) high right atrial genesis (HRA), 2) low right atrial genesis (LRA), and 3) left atrial genesis (LA). Single premature extrastimuli after 8 basic drive trains (600 ms) were delivered at the HRA and the right ventricular apex. Three atrial electrophysiologic parameters were evaluated at three atrial sites, i.e., 1) HRA, 2) LRA, and 3) coronary sinus. The atrial vulnerability parameters were as follows; 1) %A2/A1: % prolongation of atrial electrogram duration during premature beat (A2) in comparison with basic drive (A1), 2) wavelength index (WLI): calculated as [effective refractory period]/[A2], and 3) retrograde activation index (RAI): calculated as [A1 during retrograde activation; i.e., RVA pacing/[A1 during antegrade activation, i.e., HRA pacing], shown as a percentage. The Afib genesis was HRA in 20, LRA in 12 and LA in 7 patients. At the HRA recording site, %A2/A1 and RAI were the largest and WLI the shortest in the HRA genesis group in comparison with the other two groups. Similarly, at the LRA and LA recording sites, %A2/A1 and RAI were the largest and WLI the shortest in the groups with Afib genesis at these recording sites. In patients with inducible Afib, %A2/A1 and RAI were the highest and WLI the shortest at the atrial recording site close to the site of Afib genesis. Atrial wave prolongation during retrograde atrial activation, possibly the anisotropic conduction, was considered to play a role in initiating Afib as well as a conduction delay during the atrial premature beat.

Adult↗

PubMed1999

Predicting the effect of gonadotropin-releasing hormone (GnRH) analogue treatment on uterine leiomyomas based on MR imaging.

PURPOSE: To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue. MATERIAL AND METHODS: The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length x width x depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound. RESULTS: The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29+/-0.11). The size ratio for the hypointense tumors was 0.82+/-0.14, and 0.82+/-0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01). CONCLUSION: Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas.

Administration, Inhalation↗

PubMed1999

[Cochlear implantation in children with inner ear malformation and postoperative performance].

Cochlear implantation in children with cochlear malformation is on the rise. However, only one case has been reported in Japan. The objective of this paper is to report the authors' experiences with cochlear implants in children with cochlear malformations and, to investigate the morphological classification of cochlear malformation, surgical procedure, complications, and speech perceptions after implantation. Five children (6 ears, including 1 Usher's syndrome and 1 CHARGE association) with congenital inner ear malformations were implanted with multichannel cochlear implants (Nucleus Mini 22 device) between 1994 and 1998. Malformations included common cavity deformity 2, and incomplete partition 4. On the other hand, 4 cases with incomplete partition deformity underwent cochlear implantation by the transmastoid facial recess approach, 2 patients with common cavity deformity received implantation by the transmastoid labyrinthotomy approach. Complications such as facial twitching, cerebrospinal fluid (CSF) gusger, and flap-related problems were encountered. Facial twitching occurred in 1 of 2 patients with common cavity where the electrode array extended into the internal auditory canal. CSF gusher was encountered in 1 of 4 patients with incomplete partition, and revision surgery was performed one week later. One patient had delayed cochlear implant infection and a split pericranial flap was used to cover the defect in the skin flap. Within 6 months, however, the revised pedestal site broke down because of recurrent flap infection. Finally, the cochlear implant was explanted, and the patient underwent a new cochlear implantation in the contralateral ear. All the patients had satisfactory speech reception and word acquisition, but still poor phonetic expression.

Cerebrospinal Fluid Otorrhea↗

PubMed1999

[Clinical outcome of catheter fragmentation and aspiration therapy in patients with acute pulmonary embolism].

The clinical usefulness of catheter fragmentation and aspiration therapy was studied in 8 patients with acute pulmonary embolism who received thrombolytic therapy using urokinase or tissue-type plasminogen activator (t-PA) (thrombolysis group) and 8 patients who underwent catheter fragmentation and aspiration therapy using a percutaneous transluminal coronary angioplasty (PTCA) guide catheter (catheter group). The patients were selected from 20 patients with a definite diagnosis of acute pulmonary embolism based on pulmonary arteriography and nuclear imaging. Urokinase (48 x 10(4) to 96 x 10(4) unit/day) or t-PA (12 x 10(6) unit/day) was administered intravenously for mean 4 days in the thrombolysis group. Pulmonary artery pressure was first measured using a Swan-Ganz catheter via the jugular vein or the femoral vein in the catheter group. Then, a PTCA guide catheter was advanced into the pulmonary artery, and the thrombus was disrupted repeatedly using a Radifocus wire, followed by manual aspiration. Subsequent treatment consisted of intravenous infusion of heparin (10,000 to 15,000 unit/day) and urokinase (24 x 10(4) to 48 x 10(4) unit/day) for mean 6 days. Partial revascularization was achieved in all patients in both groups. Five patients in the thrombolysis group died within 1 month due to respiratory failure, re-embolization, and/or hemorrhagic complications. One patient in the catheter group died of hemorrhagic shock. Pulmonary artery systolic pressure in the catheter group was significantly reduced from 47.4 to 26.5 mmHg (p < 0.01). Catheter treatment of acute pulmonary embolism associated with acute circulatory failure such as shock can lead to rapid hemodynamic improvement. In contrast, thrombolysis is an effective treatment, but bleeding problems are common and caution is required. Catheter fragmentation and aspiration therapy is effective for acute pulmonary embolism, is minimally invasive, and should be considered the treatment of first choice.

Acute Disease↗

PubMed1998

Constitutively active Galpha12, Galpha13, and Galphaq induce Rho-dependent neurite retraction through different signaling pathways.

In neuronal cells, activation of a certain heterotrimeric G protein-coupled receptor causes neurite retraction and cell rounding via the small GTPase Rho. However, the specific heterotrimeric G proteins that mediate Rho-dependent neurite retraction and cell rounding have not yet been identified. Here we investigated the effects of expression of constitutively active Galpha subunits on the morphology of differentiated PC12 cells. Expression of GTPase-deficient Galpha12, Galpha13, and Galphaq, but not Galphai2, caused neurite retraction and cell rounding in differentiated PC12 cells. These morphological changes induced by Galpha12, Galpha13, and Galphaq were completely inhibited by C3 exoenzyme, which specifically ADP-ribosylates and inactivates Rho. The tyrosine kinase inhibitor tyrphostin A25 blocked the neurite retraction and cell rounding induced by Galpha13 and Galphaq. However, tyrphostin A25 failed to inhibit the Galpha12-induced neuronal morphological changes. On the other hand, inhibition of protein kinase C or elimination of extracellular Ca2+ blocked the neurite retraction and cell rounding induced by Galphaq, whereas the morphological effects of Galpha12 and Galpha13 did not require activation of protein kinase C and extracellular Ca2+. These results demonstrate that activation of Galpha12, Galpha13, and Galphaq induces Rho-dependent morphological changes in PC12 cells through different signaling pathways.

ADP Ribose Transferases↗

PubMed1998

Enhancement of immobility in mouse forced swimming test by treatment with human interferon.

We investigated the depression induced by human interferons using the forced swimming test in mice. Intravenous (i.v.) administration of interferon-alpha s (natural interferon-alpha, recombinant interferon-alpha-2a and recombinant interferon-alpha-2b, 600-60000 IU/kg) increased the immobility time in the forced swimming test in a dose-dependent manner, but natural interferon-beta and recombinant interferon-gamma-1a did not affect the immobility time. The increase in the immobility time induced by recombinant interferon-alpha-2b peaked at 15 min after dosing. Administration of recombinant interferon-alpha-2b (6000 IU/kg, i.v.) once daily for 7 consecutive days increased the immobility time, but natural interferon-beta and recombinant interferon-gamma-la did not. Recombinant interferon-alpha-2b in combination with the anti-depressants imipramine (10 mg/kg, i.p.) and mianserin (20 mg/kg, i.p.) did not increase the immobility time. These results suggest that interferon-alpha has a greater potential for inducing depression than interferon-beta and -gamma, and that anti-depressants are effective against interferon-alpha-induced depression.

Animals↗

PubMed1998

Osteogenic potential of cultured periosteal cells in a distracted bone gap in rabbits.

Osteogenesis of cultured periosteal cells was investigated in a bone-defective gap that was created artificially by distraction in the tibia of 12-week-old rabbits. A 10-mm circumferential length of periosteum was stripped from each stump of the osteotomized tibia, and the tibia was distracted rapidly (2 mm/day), resulting in disturbance of callus formation. Periosteal-derived cells, which were isolated from the contralateral tibia, were introduced into cell culture, subcultured twice to a population of 5 x 10(7) cells, and then injected into the defective bone gap when distraction was complete. Following inoculation of the cultured cells, significant new bone formation in the bone gap was observed. The control group which did not undergo cell transplantation showed only slight new callus formation which is supposed to be formed by osteogenic cells from the bone marrow. The bone mineral content of newly formed bone between the distracted tibia was analyzed quantitatively on radiographs. Histologically, the transplanted cells initially formed a mass at the injected site and then gradually differentiated into bone tissue from the peripheral region. Bromodeoxyuridine immunohistochemical stain was utilized to investigate the localization of the transplanted cells. The present study confirms that the orthotopically implanted periosteum-derived cells facilitate osteogenesis in a bone defect created using distraction in rabbits.

Animals↗

PubMed1998

New stacking variant of Laves phase found in (Ti0.95 V0.05) Co2 alloy.

Microstructures of the Laves phase alloy, (Ti0.95 V0.05) Co2, were studied by high resolution electron microscopy and electron diffraction. In this alloy system, coexistence of several kinds of layered structures was observed. Among these structures, a new stacking variant was found and was analyzed to be ABCAB'A'C'BCA'C'B'. This structure belongs to the trigonal system of the space group P3m1 (no. 164). The lattice parameters presented in the hexagonal system are a = 0.4727 +/- 0.0009 nm and c = 4.628 +/- 0.008 nm. This structure is called 12T in the Ramsdell notation and 4323 in the Zhdanov symbol, and is classified into hP3m1-(6i)5(3f)(3e)(2d)12(2c)6 using the Wyckoff notation.

Alloys↗

PubMed1998

Cloning and sequence analysis of the poly (3-hydroxyalkanoic acid)-synthesis genes of Pseudomonas acidophila.

Pseudomonas acidophila can grow with CO2 as a sole carbon source by the possession of a recombinant plasmid that clones genes that confer chemolithoautotrophic growth ability derived from the H2-oxidizing bacterium Alcaligenes hydrogenophilus. H2-oxidizing bacteria produce poly(3-hydroxybutyric acid) (PHB) from CO2, but recombinant P. acidophila can produce the more useful biopolymer poly(3-hydroxyalkanoic acid) (PHA). In this study, the pha genes of P. acidophila were cloned and a sequence analysis was carried out. A gene library was constructed using the cosmid vector pVK102. A recombinant cosmid carrying the pha genes was selected by the complementation of a PHB-negative mutant of Alcaligenes eutrophus H16. The resulting recombinant cosmid pIK7 contained a 14.8-kb DNA insert. Subcloning was done. and the recombinant plasmid pEH74 was selected by hybridization with the A. eutrophus H16 pha genes. Escherichia coli possessing pEH74 produced PHB, indicating that pEH74 contained the pha genes of P. acidophila. The nucleotide sequences of the PHA-synthesis genes phaA (beta-ketothiolase), phaB (acetoacetyl-CoA reductase), and phaC (PHA synthase) in pEH74 were determined. The homologies of phaA, phaB, and phaC between P. acidophila and A. eutrophus H16 were 64.7, 76.1 and 56.6%, respectively.

Acetyl-CoA C-Acyltransferase↗

PubMed1998

Tracheal occlusion in the fetal rat: a new experimental model for the study of accelerated lung growth.

BACKGROUND: Prenatal tracheal occlusion accelerates fetal lung growth, but the mechanism of this phenomenon is unknown. Previous animal models have been limited by expense, lack of species-specific molecular probes, or the stage of lung development when studies could be performed. To provide a model that is more amenable to systematic analysis, we have developed an in vivo rat model of prenatal tracheal occlusion. METHODS: Time-dated pregnant rats underwent laparotomy at 19 days' gestational age (term, 22 days). The fetal head and neck were exteriorized through a hysterotomy, and the trachea was ligated under a dissecting microscope. The fetus was returned to the amniotic cavity, and the uterine and maternal abdominal incisions were closed. The dam and the fetuses were killed at 21.5 days' gestational age, and the fetal lungs were assessed for lung growth and compared with nonoperated littermate controls. RESULTS: Thirty-two of 50 manipulated fetuses survived. Of the 32 survivors, successful tracheal ligation was confirmed in 20, and these 20 fetuses were compared with 33 littermate controls. Fetal body weight (4.81+/-0.26 g v 4.87+/-0.41 g) and heart weight (0.05+/-0.01 g v 0.05+/-0.01 g) were not significantly different between ligated fetuses and littermate controls, whereas the wet lung weight (0.30+/-0.06 g v 0.13+/-0.02 g, P<.01), lung-to-body-weight ratio (6.34+/-1.16% v 2.64+/-0.41%, P<.01), dry lung weight (17.4+/-2.45 mg v 12.1+/-1.87 mg, P<.01), total lung DNA (1210+/-371 microg v 828+/-208 microg, P<.01), and total lung protein (14.3+/-5.3 mg v 8.7+/-1.7 mg, P<.01) were increased significantly in the ligated fetuses. The enlarged lung demonstrated normal histology findings after inflation fixation. CONCLUSIONS: Prenatal tracheal occlusion during the canalicular stage of lung development accelerates lung growth in the rat. In comparison with other large animal models, this relatively inexpensive small animal model has the distinct advantages of a short gestation, a large number of fetuses per litter, the availability of a developmental model of congenital diaphragmatic hernia, and the availability of well-defined molecular probes to investigate the mechanism of tracheal occlusion-induced lung growth.

Animals↗

PubMed1998

Tracheal occlusion reverses the high impedance to flow in the fetal pulmonary circulation and normalizes its physiological response to oxygen at full term.

PURPOSE: The authors hypothesized that in utero tracheal occlusion would reverse the high impedance to pulmonary blood flow associated with congenital diaphragmatic hernia (CDH) and normalize the fetal physiological response to oxygen at term. METHODS: Three experimental groups were studied. Six fetal lambs (CDH group) underwent creation of a left CDH at 80 days' gestation, an additional six fetal lambs underwent left CDH creation at 80 days' gestation followed by fetal tracheal occlusion performed at 108 days' gestation (CDH + TO group), and four control fetal lambs (control group) underwent a sham procedure at 80 days gestation. All lambs were followed up at 2-week intervals by pulse wave Doppler echocardiography. At each time-point the pulsatility index (PI) was calculated for the left branch pulmonary artery from the Doppler blood velocity waveform. Near term (term, 145 days gestation) at 136 days gestation, measurements were repeated under maternal normoxia and hyperoxia. The fetal lungs were harvested and processed for morphometric analysis by radial alveolar counts (RAC) and lung-to-body-weight ratios (LBWR) as measures of lung growth. RESULTS: At 136 days' gestation the PI of the CDH + TO group (2.88 +/- 0.29) and control group (3.97 +/- 0.37) were significantly lower compared with the PI of the CDH group (9.02 +/- 0.50). There was a significant decrease in the PI of both the CDH + TO group and the control group with maternal hyperoxia at term, whereas the CDH group showed no change. The lungs of the CDH group fetuses were significantly smaller by LBWR and RAC than both CDH + TO and control fetuses. CONCLUSIONS: An elevated PI is associated with pulmonary hypoplasia, fetal tracheal occlusion reverses this finding, and results in a normal fetal physiological response to changes in oxygen tension at term.

Analysis of Variance↗

PubMed1998

Gastrointestinal amyloidosis secondary to hypersensitivity vasculitis presenting with intestinal pseudoobstruction.

A 22-year-old woman developed sudden hepatic encephalopathy and severe intestinal bleeding. She was diagnosed with acute fatty liver and hypersensitivity vasculitis and was successfully treated with whole plasma exchange, methylprednisolone pulse therapy, and transcatheter arterial embolization. Twenty-seven months later, she began complaining of lower abdominal fullness, tenderness, and nausea and vomiting. Histologic examination showed that she had developed gastrointestinal and renal amyloidosis with intestinal pseudoobstruction and proteinuria. The immunohistochemical study of the stomach, rectum, and kidney with anti-amyloid A fluorescent antibody showed that the systemic amyloid deposit was secondary to her underlying disease. This is the first report of amyloidosis occurring secondary to hypersensitivity vasculitis.

Adult↗

PubMed1998

Quantification of human lithostathine S2-5 forms using the antibody to the N-terminal peptide region.

Lithostathine S2-5 inhibits in vitro crystal growth of CaCO3. We developed an antibody against the peptide region responsible for inhibitory effect to determine whether lithostathine S2-5 levels are different in the pancreatic juice of patients with and without chronic pancreatitis. The antibody against the synthetic peptide of the N-terminal end of lithostathine S2-5 detected lithostathine S2-5 but not lithostathine S1 or lithostathine extracted from pancreatic calculi. Lithostathine S2-5 was detected in samples of pancreatic juice protein by immunoblotting using the specific antibody. The concentration of lithostathine S2-5 was compared between control and chronic pancreatitis groups. The mean concentrations of lithostathine S2-5 were significantly (p=0.002) lower in chronic pancreatitis, 16.3 microg/mg of total protein, than in the control, 47.1 microg/mg of total protein. A decreased concentration of lithostathine S2-5 seems to increase the risk of stone formation in the ducts during the course of chronic pancreatitis because of insufficient inhibition of CaCO3 crystal growth.

Adult↗

PubMed1998

[Investigation of the influence of hemodialysis membranes and factors associated with hemodialysis on serum (1-->3)-beta-D-glucan].

The measurement of serum (1-->3)-beta-D-glucan (beta-glucan) is commonly used in the clinical stage. Although it has been considered very useful in the early diagnosis of deep mycosis, it is influenced by several factors, one of which is hemodialysis. Therefore, we decided to investigate clinically the influence of hemodialysis membranes on serum beta-glucan. Plasma samples were collected from 26 patients receiving hemodialysis in Kawasaki Medical School Hospital. The kinds of hemodialysis membranes examined were four synthetic polymers and three natural polymers. We also measured beta-glucan in five washing liquids used in the hemodialysis circuit, five dialyzates, two sodium heparin and two filling liquids for wet type dialyzers to investigate the influence of other factors associated with hemodialysis on serum beta-glucan. Elevations of beta-glucan were observed in some cases treated by hemodialysis apparatus using a saponified cellulose acetate membrane. But, in all cases treated by hemodialysis using a cellulose triacetate membrane, slight elevations of beta-glucan were observed. No significant increases in beta-glucan after hemodialysis were observed in the cases treated by hemodialysis using a synthetic polymer membrane. Elevations of beta-glucan is sodium heparin and in one of the filling liquids for the wet type dialyzer were observed. We, therefore, concluded that there are some other factors having an effect on serum beta-glucan besides the hemodialysis membrane in the patients treated by hemodialysis.

Adolescent↗

PubMed1998

Gene expression of bone matrix proteins and endothelin receptors in endothelin-1-deficient mice revealed by in situ hybridization.

Endothelin-1 (ET-1) was first found as a vasoconstrictor protein excreted by vascular endothelial cells, but recently ET-1 has been considered to have widespread functions that include regulation of osteochondrogenic metabolism. We analyzed sections of head regions in ET-1 knockout mice that are known to have abnormalities in pharyngeal arch-derived tissues and found that there was severe hypoplasia in facial bones. The hypoplasia suggests that the matrix mineralization system of facial bones is disrupted in ET-1-/- homozygous mice. To elucidate whether osteogenic cells in facial bones are the targets for ET-1 and whether expression of bone matrix genes are modulated by ET-1, we examined gene expression of ET-1 receptors, ETA and ETB, and that of the bone matrix proteins, osteonectin (ON) and osteopontin (OP), both in the head regions of ET-1+/- heterozygous and ET-1-/- homozygous mice by means of in situ hybridization. Different patterns of expression between ETA and ETB mRNAs were observed in both groups. In 18.5 days post coitus fetuses, ETA mRNA was most strongly expressed in osteogenic cells along craniofacial bones, but ETB mRNA was most strongly expressed in trunks of trigeminal nerve. This finding suggests that ET-1 may modulate osteogenic cells through ETA receptor but not through ETB receptor. The expression patterns of ETA, OP, and ON mRNAs were distinct between the two groups. In the lower jaw of ET-1+/- heterozygous mice, the ETA, ON, and OP mRNA positive cells were scattered in the inner and outer regions of the thick bone matrix, but in ET-1-/- homozygous mice, cells containing those mRNAs were located close to each other at the surface of thin bone matrix. However, cellular expression of ON and OP mRNAs in osteogenic cells of ET-1-/- homozygous mice was not suppressed as compared with ET-1+/- heterozygous mice. We conclude that ET-1 may regulate proliferation and migration of osteogenic cells in the maxillofacial region, rather than modulating the expression level of ON and OP mRNAs.

Animals↗