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Biomedical subjects

Y Terada

Publications and source records attributed to Y Terada.

At least 271 records · Page 15Linked to original sources
PubMed1993

[A case of coronary artery bypass grafting (CABG) with acquired tracheobronchomalacia].

Acquired tracheobronchomalacia is often overlooked because the symptoms are similar to those of chronic obstructive lung disease. A 55-year-old man underwent an emergency CABG because of unstable angina pectoris. CABG was performed uneventfully. On the third day after operation, severe cough and dyspnea were persisted, followed by the episode of ventricular fibilliration. Cardiopulmonary resuscitation was necessary. CT scan of the chest showed crescent narrow deformity from the lower trachea to the right main bronchus. Bronchoscopic examination revealed 90% stenosis of the trachea during coughing, and edematous tracheal mucosa. Acquired tracheobronchomalacia is an illness of the middle-aged and the elderly and tends to be progressive. Recently, because the patients for CABG have become older, tracheobronchomalacia should be taken into consideration.

Angina, Unstable↗
PubMed1993

[Two episodes of fatal ventricular arrhythmia associated with use of electrosurgical unit during redo MVR procedure].

We report a case of ventricular fibrillation in the first episode and ventricular tachycardia in the second episode that occurred with use of electrosurgical unit during redo MVR procedure. Both arrhythmia occurred five to ten seconds after application of the electrosurgical knife in the coagulation mode to the sternal periosteum. The patient was immediately resuscitated with return to sinus rhythm using direct-current electroshock. In the literature, it was reported that large direct-current potentials were generated during electrosurgery and that these potentials increased with increasing sparking at the active electrode. Care should be always taken because they may cause fatal ventricular arrhythmia.

Adult↗
PubMed1993

[Hemodynamic situation immediately after cardiopulmonary bypass in cases of coronary artery bypass grafting (CABG) using both bilateral internal thoracic arteries (ITAs) and right gastroepiploic artery (GEA)].

Hemodynamic situation immediately after cardiopulmonary bypass was studied in cases of CABG using bilateral ITAs and right GEA. Though cardiac output was kept greater than 4.0 l/min, the blood pressure soon after weaning from cardiopulmonary bypass was low in patients who necessitated further circulatory assist, intraaortic balloon pumping (IABP) and/or additional surgical bypass procedure. In cases of CABG using arterial grafts and no vein graft, the perfusion pressure is most important to stabilize the hemodynamic status because low pressure may provoke peripheral vasoconstriction resulting in spastic reaction of the ITA and GEA. These arterial grafts seemed to keep the characteristics as the peripheral artery. Some papers pointed out less flow capacity of arterial grafts compared with that of saphenous vein graft, but CABG with arterial grafts alone was safe clinically if care is taken for keeping the perfusion pressure as high as preoperatively.

Adult↗
PubMed1993

[A case report of surgically treated tracheobrachiocephalic artery fistula following tracheostomy].

The patient was a 17 year-old-boy with mental retardation and cerebral palsy, who underwent tracheostomy because of tracheobronchomalacia and tongue swallowing three months ago. After minimal tracheostomy bleeding was noted for a few days, massive hemorrhage occurred suddenly. The patient was severely hypotensive. The cuff on the tracheostomy tube was hyperinflated, which stopped the bleeding temporarily. Through a median sternotomy and collar incision, a pin hole-sized defect in the medial surface of the brachiocephalic artery at the tracheal balloon was repaired by suture. The tracheal defect allowed visualization of the tracheal cannula balloon. The pectoralis major muscle flap was interposed between the tracheal defect and the artery. The tracheal defect was packed with muscle. Seven days after the operation, the second operation was done for recurrent bleeding. The defective segment of brachiocephalic artery was resected and the ends were oversewn with monofilament sutures. Continuous irrigation with povidone-iodine solution was continued for purulent mediastinitis. We believe that interruption of blood flow of the brachiocephalic artery, interposition and packing of muscle flap over the tracheal defect and continuous irrigation for infection were effective treatment of choice.

Adolescent↗
PubMed1993

[Case report of MRSA sepsis required two valve replacement twice a year--trying case with hyperthermal extracorporeal circulation].

We report a case in conjunction with MRSA sepsis, who needed re-mitral valve replacement (re-MVR) and re-tricuspid valve imposition (re-TVI), and who was successfully treated with a number of antibiotics in conjunction with hyperthermal extracorporeal circulation. Initially, we performed MVR and tricuspid valve superimposition on a 62-year-old woman lationing under the MRSA sepsis condition to control against heart failure. However, she developed a fever following the first operation, and MRSA was detected from her blood cultivation. She thus underwent treatment employing many kinds of antibiotics. A thickened C.E. valve at the tricuspid valve cardiac echogram suggested PVE, we performed a second operation of re-MVR and re-TVI about a year after the first operation. We used a tangl of antibiotics during the operation, adding Vancomycin into the extracorporeal circulation, and utilized hyperthermal extracorporeal circulation. This patient's postoperative course was uneventful, with no recurrence arising at 23 months after the second operation.

Anti-Bacterial Agents↗
PubMed1993

[Mitral valve re-replacement for a patient with multiple myeloma].

Mitral valve re-replacement was successfully undertaken in a 70-year-old female patient with primary tissue failure of mitral bioprosthesis and multiple myeloma (MM) through right lateral thoracotomy with minimum dissection. Considering the post-operative anti-coagulant therapy, bioprosthesis was chosen in this complicated case. Patients with MM usually show a bleeding tendency associated with abnormally elevated IgG which covers the surface of coagulation factors. Safety range of serum IgG concentration in the patients with MM who require open heart surgery, have not defined yet. Excessive serum IgG leads the coagulation disorder and organ perfusion problem because of increase of blood viscosity. Those problems become serious when the serum IgG concentration exceed 2,500 mg/dl. (1) Only if serum IgG level below 2,5000 mg/dl, valve replacement will be able to perform safely with minimum dissection through the thoracotomy for patients with MM. (2) Bioprosthesis might be optionally chosen in such case (3). In case of serum IgG level over 2,500 mg/dl, preoperative plasma ex-change should be recommended.

Aged↗
PubMed1992

Availability of the in situ right gastroepiploic artery for coronary artery bypass.

The right gastroepiploic artery (GEA) has been successfully used as a coronary bypass graft recently. We examined the in situ GEA graft length required from the pyloric portion to the site of coronary anastomosis at the time of operation. Measured GEA length was 17.0 +/- 1.7 cm for the posterior descending artery anastomosis in 17 patients, 17.8 +/- 1.7 cm for the main right coronary artery anastomosis in 13 patients, 22.0 +/- 2.3 cm for the posterolateral branch anastomosis in 7 patients, and 21.0 cm for the left anterior descending artery anastomosis in 1 patient. We examined 228 randomly selected abdominal angiograms and measured the internal diameter of the right GEA at every 2-cm interval from its origin. Probability of availability of the in situ GEA graft for each site of anastomosis was 97% to the right coronary artery and 88% to the anterior descending or the circumflex artery when the internal diameter of GEA was 1.5 mm or greater. From an anatomical standpoint, we concluded that the GEA can be assumed available without preoperative angiography.

Adult↗
PubMed1992

Renal effects of alacepril in essential hypertension.

Short-term effects of alacepril, an angiotensin-converting enzyme inhibitor (ACEI), on renal function and hemodynamics were investigated in 10 hypertensive subjects (aged 55.7 +/- 9.5 years, mean +/- SD). Renal plasma flow (RPF) and glomerular filtration rate (GFR) were examined before and after 12-week administration of alacepril, by [131I]hippuran and [99mTc]DTPA, respectively. Alacepril (50 mg/day) caused a significant decrease in both systolic and diastolic blood pressure (SBP and DBP, from 161 +/- 8 to 140 +/- 10 mm Hg and from 100 +/- 3 to 90 +/- 5 mm Hg, respectively). Alacepril increased GFR (from 63.4 +/- 22.2 to 69.1 +/- 22.1 ml/min/1.73 m2, p less than 0.05) without changing RPF (from 438 +/- 194 to 432 +/- 148 ml/min/1.73 m2, p greater than 0.05). Serum creatinine and electrolytes were not changed by alacepril administration. These data show that short-term alacepril administration improves renal function, probably owing to relaxation of renal vasoconstriction.

Adult↗
PubMed1992

Hormone and autacoid regulation of cAMP production in rat IMCD subsegments.

The inner medullary collecting duct (IMCD) of the rat consists of two structurally and functionally distinct segments, i.e., the initial and the terminal IMCD. To identify factors that may regulate the transport function in the IMCD segments, we assessed whether catecholamines, carbachol, prostaglandin E2 (PGE2), bradykinin, glucagon, calcitonin, parathyroid hormone, or epidermal growth factor affects adenosine 3',5'-cyclic monophosphate (cAMP) production in microdissected tubules in the presence and absence of arginine vasopressin (AVP, 0.1 nM). All experiments were performed in the presence of 3-isobutyl-1-methylxanthine, and cAMP was measured by radioimmunoassay. Epinephrine (greater than or equal to 50 nM) and clonidine (greater than or equal to 1 microM) markedly decreased AVP-induced cAMP levels in both IMCD segments. However, phenylephrine did not show an effect. The inhibitory effect of epinephrine was blocked by yohimbine (50 nM) but not by prazosin (50 nM). In isolated perfused terminal IMCDs, epinephrine inhibited AVP-stimulated urea permeability. Isoproterenol (1 microM), in the absence of AVP, caused a significant increase in cAMP level only in the initial IMCD. Propranolol (1 microM) inhibited this isoproterenol effect, but atenolol did not. Dopamine (less than or equal to 1 microM) had no effect on cAMP levels in either IMCD segment. Carbachol, PGE2, and the various peptide hormones had no effect on cAMP levels (+/- AVP) in either IMCD segment. We conclude that an adrenergic beta 2-receptor is present only in the initial IMCD, where its occupation increases cAMP production. We conclude also that an adrenergic alpha 2-receptor is present in both IMCD segments, where its occupation inhibits AVP-induced cAMP production.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Age-related changes in alpha 1- and alpha 2-chain type IV collagen mRNAs in adult mouse glomeruli: competitive PCR.

Studies of age-related changes in glomerular extracellular matrix (ECM) synthesis in normal mice have been hampered by the difficulty of isolating sufficient numbers of intact glomeruli and by the inability to quantify different mRNA species. The purpose of this study was to identify and quantitate the individual mRNAs coding for alpha 1- and alpha 2-chains of type IV collagen in isolated, single glomeruli of normal mice at different ages. These data on normal ECM synthesis were necessary for the understanding of glomerulosclerosis, a condition characterized by excess deposition of collagen. Pools of freshly microdissected adult mouse glomeruli were reverse transcribed in situ, and alpha 1-IV and alpha 2-IV collagen mRNAs were individually amplified by means of specific primers and the polymerase chain reaction (PCR), according to a previously published method. A competitive PCR assay, based on utilization of mutated cDNAs, allowed the reproducible, quantitative, and separate determination of the absolute amounts of both alpha 1-IV and alpha 2-IV mRNAs measured, as their respective cDNAs, in one-tenth of one glomerulus. The levels of alpha 1-IV and alpha 2-IV collagen mRNA were 208 +/- 36.0 x 10(-4) and 161.2 +/- 18.6 x 10(-4) amol/glomerulus in 5-wk-old mice. There were no significant age-related differences at 8, 12, and 24 wk. The mean levels over this period were 60.2 +/- 4.9 x 10(-4) for alpha 1-IV collagen mRNA and 63.9 +/- 5.8 x 10(-4) amol/glomerulus for alpha 2-IV collagen mRNA. Two of three 24-wk-old mice had mild glomerulosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1992

Different localization of two types of endothelin receptor mRNA in microdissected rat nephron segments using reverse transcription and polymerase chain reaction assay.

Recent studies have revealed that endothelins (ETs) have at least two types of receptors. One receptor has high affinity to ET-1 and ET-2 and low affinity to ET-3 (A type). The other receptor binds almost equally to ET-1, ET-2, and ET-3 (B type). In this study, microlocalization of mRNA coding for the A-type and B-type ET receptors was carried out in the rat kidney using a reverse transcription and polymerase chain reaction assay of individual microdissected renal tubule segments along the nephron, glomeruli, vasa recta bundle, and arcuate arteries. Large signals for the B-type receptor polymerase chain reaction product were detected in the initial and terminal inner medullary collecting duct and the glomerulus, while small signals were found in the cortical collecting duct and outer medullary collecting duct, vasa recta bundle, and arcuate artery. In contrast, A-type receptor mRNA was detected only in the glomerulus, vasa recta bundle, and arcuate artery. Thus, the two ET receptor subtypes are distributed differently along the nephron. This suggests that the two types of receptors and ET families may affect kidney functioning in different ways.

Animals↗
PubMed1992

Polymerase chain reaction localization of constitutive nitric oxide synthase and soluble guanylate cyclase messenger RNAs in microdissected rat nephron segments.

Stimulation of the release of nitric oxide (NO) in the kidney has been shown to result in renal hemodynamic changes and natriuresis. NO is a potent stimulator of soluble guanylate cyclase, leading to an increase of cyclic GMP. The precise localization of NO synthase and soluble guanylate cyclase in the renal structure is not known. In this study, the microlocalization of mRNAs coding for constitutive NO synthase and soluble guanylate cyclase was carried out in the rat kidney, using an assay of reverse transcription and polymerase chain reaction in individual microdissected renal tubule segments along the nephron, glomeruli, vasa recta bundle, and arcuate arteries. A large signal for constitutive NO synthase was detected in inner medullary collecting duct. Small signals were detected in inner medullary thin limb, cortical collecting duct, outer medullary collecting duct, glomerulus, vasa recta, and arcuate artery. Soluble guanylate cyclase mRNA is expressed largely in glomerulus, proximal convoluted tubule, proximal straight tubule, and cortical collecting duct, and in small amounts in medullary thick ascending limb, inner medullary thin limb, outer medullary collecting duct, inner medullary collecting duct, and the vascular system. Our data demonstrate that NO can be produced locally in the kidney, and that soluble guanylate cyclase is widely distributed in glomerulus, renal tubules, and the vascular system.

Amino Acid Oxidoreductases↗
PubMed1992

Messenger RNA expression and synthesis of endothelin-1 along rat nephron segments.

The kidney both produces and responds to endothelin. We examined the production and the expression of mRNA of endothelin-1 (ET-1) in tubule suspensions and microdissected nephron segments. ET-1 production was measured by RIA using an ET-1-specific antibody. We applied the reverse transcription and polymerase chain reaction (PCR) technique to detect ET-1 mRNA along the nephron segments. Stimulation of ET-1 production was observed in the presence of FCS and transforming growth factor-beta (TGF-beta) in inner medullary tubules but not in cortical or outer medullary tubule suspensions. Among dissected nephron segments, ET-1 production was observed in glomeruli and inner medullary collecting ducts (IMCD), whereas it was negligible in proximal convoluted tubules (PCT) and medullary thick ascending limbs (MAL). In addition, the PCR product of ET-1 mRNA was also higher in glomeruli and IMCD, whereas it was undetectable in PCT and MAL. Furthermore, FCS and TGF-beta increased ET-1 mRNA in microdissected glomeruli and IMCD. These data clearly demonstrated that the production sites of ET-1 are glomeruli and IMCD among the nephron segments. ET-1 is an autocrine factor in these sites.

Animals↗
PubMed1992

Plasma high density lipoprotein in anemic cattle infected with Theileria sergenti.

Changes in plasma concentration of lipid composition were analysed in cattle with anemia due to Theileria sergenti infection. Plasma levels of phospholipids, cholesterol, free cholesterol, high density lipoprotein cholesterol, and vitamin E decreased to 40-67% of the pre-infection levels, corresponding to the decrease of PCV due to the infection. However, no definite changes were detected in plasma level of triglyceride. By gradient centrifugation, it was confirmed that lipid components, other than triglyceride, occur in high density lipoprotein (HDL) and these decreases lowered the HDL value. There was no correlation between this phenomenon and liver function. As similar changes in lipid composition were also observed in phlebotomized calves, it was considered that this phenomenon might partially depend on the acceleration of erythropoiesis as a reaction to anemia caused by T. sergenti infection.

Anemia↗
PubMed1992

The effects of cromolyn sodium in dogs undergoing high-frequency oscillation superimposed on conventional mechanical ventilation.

The effects on gas exchange of superimposition of high-frequency oscillation (HFO) (40 Hz) on conventional mechanical ventilation were investigated in mongrel dogs with eucapnic gas exchange on conventional mechanical ventilation (CMV). The dogs were anesthetized, paralyzed, and ventilated with CMV until stable. Oscillation was then superimposed for 15 min, followed by CMV alone for a further 30 min. During HFO superimposed on CMV (CMV-HFO), the arterial carbon dioxide tension (PaCO2) increased from 43.6 +/- 1.2 mm Hg to 47.2 +/- 1.4 mm Hg (p less than 0.02), whereas the arterial oxygen tension (PaO2) did not change at all. The change was inhibited completely by administration of intravenous cromolyn sodium (CS) (6 mg/kg/min). The mean pulmonary arterial pressure (mPAP), cardiac output (CO), pulmonary capillary wedge pressure (PCWP), and pulmonary vascular resistance (PVR) did not change during the experiment. These results demonstrate that CMV-HFO appears to cause CO2 accumulation and eliminates the impaired O2 transfer, and that these effects are inhibited completely by CS administration.

Animals↗
PubMed1992

[Endothelin, EDRF, CGRP].

Endothelin-1 is now known to synthesized in the kidney and influence the renal function. ET-1 mRNA was detected in glomerulus and inner medullary collecting ducts using RT-PCR technique. ETA receptor mRNA was detected only in glomerulus, vasa recta bundle, and arcuate artery. ETB receptor mRNA distributed mainly in glomerulus and collecting ducts. Endothelium derived relaxing factor (EDRF) was believed to be nitric oxide, was synthesized by nitric oxide (NO) synthase from L-arginine. NO stimulates soluble guanylate cyclase and increases cGMP level. NO synthase mRNA was detected in glomerulus and inner medulla. Soluble guanylate cyclase mRNA distributed widely along the nephron segments. NO and cGMP system seems to play some roles in modulating renal functions.

Amino Acid Oxidoreductases↗