Partitioning and membrane disordering effects of ethanol and other n-alkanols in phosphatidylcholines and biologically relevant lipid mixtures.
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Alcohols↗
Biomedical subjects
H Chang
Publications and source records attributed to H Chang.
Ion channel activities of cultured rat mesangial cells.
We used the patch-clamp technique to clarify the nature of ion channels in renal mesangial cells in culture. In the cell-attached mode most patches were silent in the absence of agonists. In some patches a 25-pS nonselective channel was observed. This 25-pS cation channel was consistently observed in inside-out patches, and it was activated by intracellular Ca2+. Excised patch experiments also revealed the existence of a 40-pS K+ channel, which was activated by intracellular Ca2+. This 40-pS K+ channel was observed infrequently in the cell-attached mode. The activities of both channels were increased by arginine vasopressin or angiotensin II, resulting from an increase in intracellular Ca2+ concentration.
Angiotensin II↗
Abnormalities of carbohydrate and lipid metabolism in Dahl rats.
Plasma glucose, insulin, and triglyceride concentration, blood pressure, and insulin action on isolated adipocytes were determined in weight-matched Sprague-Dawley, Dahl salt-resistant, and Dahl salt-sensitive rats. Blood pressure and plasma glucose concentrations were not significantly different in the three groups. However, Dahl salt-sensitive rats had significantly higher plasma insulin (39 +/- 2 microunits/ml) and triglyceride (213 +/- 11 mg/dl) concentrations than did Sprague-Dawley rats (27 +/- 2 microunits/ml and 101 +/- 6 mg/dl, respectively). Values for insulin (34 +/- 4 microunits/ml) and triglyceride (159 +/- 11 mg/dl) were intermediate in Dahl salt-resistant rats. In contrast, maximal insulin-stimulated glucose transport was significantly lower in adipocytes isolated from Dahl salt-sensitive as compared with Sprague-Dawley rats (400 +/- 16 versus 523 +/- 14 fl/cell/sec), with Dahl salt-resistant rats again having intermediate values. However, the ability of insulin to maximally inhibit catecholamine-stimulated lipolysis was similar in all three groups, averaging approximately 20% of the activity present in the absence of insulin. All of these differences were seen when the rats were eating conventional chow and did not change in Dahl rats after 2 weeks of an 8% NaCl diet. On the other hand, the predicted rise in blood pressure took place in Dahl salt-sensitive rats, increasing from 147 +/- 4 to 181 +/- 6 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)
Adipose Tissue↗
Heterotopic heart transplantation--a life-saving procedure with a size-mismatched donor.
A 32-year-old B-type male weighing 60 kg suffered from end-stage dilated cardiomyopathy. Although aggressive medical treatment with dobutamine 21 micrograms/kg/min, dopamine 17 micrograms/kg/min, digoxin 0.25 mg i.v. once daily, furosemide 40 mg i.v. every 6 h, and bumetanide 0.5 mg i.v. every 6 h were given, he was finally ventilator dependent for the last 3 weeks until a B-type donor weighing 42.5 kg was found. Because of the 29.2% weight mismatch, a heterotopic heart transplantation was performed. Posterior plication mitral annuloplasty was also performed to correct the severe mitral regurgitation of the recipient heart. Postoperatively the patient remained respirator dependent for 17 days and was finally discharged in good condition on the 46th postoperative day.
ABO Blood-Group System↗
Concomitant occurrence of subchondral cyst and ruptured anterior crucial ligament at knee joint: new findings by MRI.
The magnetic resonance imaging (MRI) in 4 cases of subchondral cyst at the knee joint region, were acquired from a 1.5 Tesla imager. We found a high incidence of concomitant occurrence of subchondral cysts with a ruptured anterior cruciate ligament (ACL) in all of these cases. The 2 men and 2 women, had an average age of 35. Clinically, they complained of dull knee pain and mild instability. Conventional radiography detected subchondral cysts in 3 of them, while MRI disclosed that all of the subchondral cysts were at the tibial plateau, close to the intercondyloid eminence. To date, MRI is the only imaging modality which can depict the concomitant occurrence of a subchondral cyst and a ruptured anterior cruciate ligament at the knee joint. Whether these subchondral cysts were the consequences of the ruptured anterior cruciate ligaments as one of the causes in addition to synovial fluid intrusion and bony contusion, need further clinical observation and investigation.
Adult↗
Surgical treatment of thoracoabdominal aortic aneurysm with graft inclusion technique.
Two male patients with huge thoracoabdominal aortic aneurysms were treated surgically at the National Taiwan University Hospital (NTUH) during the last 6 years. Case 1 was 70 years old with a case of malignant lymphoma. A huge thoracoabdominal aortic aneurysm was found which ruptured suddenly during the course of chemotherapy for malignant lymphoma. An emergency operation was performed because the patient suffered from profound shock. Case 2 was 34 years old and was referred to our hospital with a huge pulsating mass over his abdomen and progressive dysphagia. Both had atherosclerosis, thought to be the underlying etiology. The surgical technique we employed was the graft inclusion technique with major branch vessel reattachment to the side holes of the graft. Postoperative surgical results were excellent. Neither spinal cord complications nor visceral organ failure was found in either case. Case 1 unfortunately died 3 months after surgery because of advanced lymphoma with many organs being involved and upper GI bleeding. Case 2 is doing well and being followed up at our OPD at present.
Adult↗
Aneurysm arising from the branch of the superior mesenteric artery.
Superior mesenteric branch aneurysms are rare and usually become symptomatic at the time of rupture. Pain, gastrointestinal blood loss and intra-abdominal hemorrhage draw attention to the presence of aneurysms in 70% of the reported cases. We report on a 64-year-old male patient who had an emergent laparotomy for acute abdominal pain at a local hospital in Changhua in March of 1988. The operative finding was an unresectable mesentric mass, and the pathologic finding of the biopsy was a chronic abscess. Because of two episodes of tarry stools after the operation, the patient was referred to the National Taiwan University Hospital for further evaluation of the intra-abdominal mass. After admission in April of 1990, abdominal sonogram and CT examinations demonstrated the presence of a multilobulated mass which was suspected to be an aneurysm. Selective superior mesenteric arteriography confirmed this diagnosis and showed that the aneurysm arose from the origin of the ileocolic branch. At surgery, the aneurysm was found to have a fistula tract communicating with the terminal ileum. The aneurysm and the associated segment of the terminal ileum were successfully removed. We herein report this unusual case.
Aneurysm↗
Anti-hypertensive effect of auriculo-acupoint pressing therapy--clinical analysis of 274 cases.
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Acupuncture Points↗
Phosphatidylinositol synthetase activities in neuronal nuclei and microsomal fractions isolated from immature rabbit cerebral cortex.
The synthesis of phosphatidylinositol was studied using a nuclear fraction N1, a microsomal fraction P3, rough (R) and smooth (S) microsomal fractions and a microsomal fraction P derived from isolated nerve cell bodies. Each fraction was prepared using cerebral cortices of 15-day-old rabbits. In assays using CDP-diacylglycerol (prepared from egg phosphatidylcholine) and myo[3H]inositol at pH 7.4, fraction N1 had the highest maximal specific rates of phosphatidylinositol synthetase (EC 2.7.8.11) (expressed per mumol phospholipid in the fraction). However the three microsomal fractions achieved maximal specific activities at liponucleotide concentrations close to 50 microM, while fraction N1 required 200 microM concentrations. In certain cases (25-120 microM CDP-diacylglycerol, and at higher pH values) fraction R had specific activities which equalled or surpassed those of N1. However, with respect to inositol, fraction N1 had a distinctly lower Km than was shown for fractions R or P3. Each of the microsomal fractions and N1 required Mg2+ for the reaction, but for N1, maximal rates could be sustained at 0.1 mM, while for the microsomal fractions the optimal Mg2+ concentration was 1 mM. For each fraction Mn2+ could not replace Mg2+ in the reaction and Mn2+ was inhibitory. The optimal pH for the reaction was between 8.0 and 9.0. Phosphatidylinositol synthetase could also be shown using fraction N1 enriched in endogenous CDP-diacylglycerol. The relatively high specific activities of fraction N1, and the differences found between N1 and the microsomal fractions, for optimal CDP-diacylglycerol and Mg2+ concentrations and for Km values for inositol, support the existence of a neuronal nuclear phosphatidylinositol synthetase.
Animals↗
Ligamentous laxity across C0-C1-C2 complex. Axial torque-rotation characteristics until failure.
The axial torque until failure of the ligamentous occipito-atlanto-axial complex (C0-C1-C2) subjected to axial angular rotation (theta) was characterized using a biaxial MTS system. A special fixture and gearbox that permitted right axial rotation of the specimen until failure without imposing any additional constraints were designed to obtain the data. The average values for the axial rotation and torque at the point of maximum resistance were, respectively, 68.1 degrees and 13.6 N-m. The specimens offered minimal resistance (approximately 0.5 N-m), up to an average axial rotation of 21 degrees across the complex. The torque-angular rotation (T-theta) curve can be divided into four regions: regions of least and steadily increasing resistances, a transition zone that connects these two regions, and the increasing resistance region to the point of maximum resistance. The regions of least and steadily increasing resistances may be represented by two straight lines with average slopes of 0.028 and 0.383 N-m/degree, respectively. Post-test dissection of the specimens disclosed the following. The point of maximum resistance corresponded roughly to the value of axial rotation at which complete bilateral rotary dislocation of the C1-C2 facets occurred. The types of injuries observed were related to the magnitude of axial rotation imposed on a specimen during testing. Soft-tissue injuries alone (like stretch/rupture of the capsular ligaments, subluxation of the C1-C2 facets, etc.) were confined to specimens rotated up to or close to the point of maximum resistance. The specimens that were subjected to rotations up to the point of maximum resistance of the curve spontaneously reduced completely on removal from the testing apparatus. Spontaneous reduction was not possible for specimens tested slightly beyond their points of maximum resistance.(ABSTRACT TRUNCATED AT 250 WORDS)
Biomechanical Phenomena↗
Direct effects of endothelin in the rat kidney.
In the present study, we tested the direct effects of endothelin (ET) on rat kidney in vivo. ET was infused into the left renal artery of anesthetized rats at a rate of 0.5, 5, 20, or 40 pmol/h. ET reduced ipsilateral urine volume (V), clearance of inulin (CIN), and clearance of p-aminohippuric acid (CPAH) in a dose-dependent manner. Thus ET at 20 pmol/h did not change V but decreased renal plasma flow (RPF) and glomerular filtration rate (GFR) by 27.6 +/- 14.3 and 30.8 +/- 10.4%, respectively, in the ipsilateral kidney. ET at 0.5 pmol/h was without effect and at 5 pmol/h had only minor effects on CIN and CPAH of ipsilateral kidney. At 40 pmol/h, ET reduced ipsilateral V, GFR, and RPF by 52.3 +/- 21.4, 58.4 +/- 14.5, and 72.5 +/- 10.6%, respectively. Filtration fraction and fractional excretion of Na remained unchanged during ET infusion. ET, 40 pmol/h, infused into the renal artery together with atrial natriuretic peptide (ANP) at a rate of 12 pmol/h reduced the ipsilateral V, GFR, and RPF by 33.2 +/- 6.3, 26.1 +/- 6.0, and 27.2 +/- 7.1%, respectively, decrements less than those with ET alone. When a calcium-channel blocker nicardipine was infused at a rate of 2.5 micrograms/h into the renal artery together with ET, 20 pmol/h, there was little change in the ipsilateral V, RPF, and GFR; ET, 40 pmol/h, with nicardipine did not change V and decreased GFR and RPF by 25.9 +/- 5.6 and 23.1 +/- 10.8%, respectively, decrements less than those without nicardipine.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
The use of TDMAC-heparin-impregnated shunt for managing aneurysm of the descending thoracic aorta.
From April 1981 to December 1988, a total of 23 patients were operated upon for the repair of an aneurysm of the descending thoracic aorta with a tridodecylmethylammonium chloride (TDMAC)-heparin-impregnated shunt. There were 20 men and 3 women. The ages ranged from 29 to 72 years with a mean of 52.3 years. The major pathological change of the aortic wall was medial cystic necrosis in 19 patients and atherosclerosis in 4. Among them, only 6 patients underwent elective surgery, while 17 patients underwent emergency operations with the surgical indication being shock in 4, oliguria in 3, persistence of chest pain in 2, massive hemoptysis in 1, rapid size progression of the aneurysm in 3, and impending rupture of the aneurysm in 4. During surgery, the aortic cross-clamping time ranged from 40 to 76 minutes with a mean of 54 minutes. Hospital death was limited to 2 patients with a mortality rate of 8.7%. Postoperative complications were noted in 5 patients, cerebrovascular accidents in 4 and transient paraparesis in 1. However, the clinical conditions recovered before those patients were discharged. The follow-up period ranged from 4 to 84 months with a mean of 32.3 months. Except for 1 patient who died of anaphylactic shock due to drug allergy, the other 20 survivors had an apparent improvement of their clinical status and life quality.
Adult↗
Aortico--left ventricular communication: report of a case.
An 11-month-old male infant whose condition had been followed since birth was referred to the National Taiwan University Hospital for management of a congenital heart disease. On admission, this infant was noted to have a systolic and diastolic precordial thrill and a grade 4/6 systolic and diastolic murmur. Echocardiography, cardiac catheterization and cineangiogram revealed aortic stenosis, aortic regurgitation and dilatation of the aortic root. Surgical repair was performed to correct this congenital anomaly due to the progressive congestive heart failure. Intraoperatively, a breach between the aortic valve and the edge of the sinus of Valsalva along the aortic annulus was found. This congenital defect was repaired with a Teflon patch successfully. Postoperatively, this patient convalesced steadily and was discharged. We report this unique case with aortico-left ventricular communication which we believe to be the ninth case in the English-language literature and the first in the Republic of China.
Aortic Aneurysm↗
Emergency surgery of patients with ruptured great vessels and profound shock.
From October 1986 to March 1989, a total of 7 patients who had preoperative profound shock underwent surgical treatment at the National Taiwan University Hospital for a ruptured aorta or vena cava. All 7 patients were men. Their age ranged from 21 to 70 years with a mean of 45 years. Emergency operations were performed due to a ruptured abdominal aortic aneurysm in 2, a ruptured dissecting thoracic aneurysm in 1, a penetrating injury which transected the intrahepatic vena cava in 2, and blunt chest injury which resulted in acute traumatic aortic transection in 2. One of these 7 patients died of acute tubular necrosis, anoxic encephalopathy and secondary sepsis, in spite of successful restoration of circulation. Two patients had postoperative complications. One had a transient paraparesis after an aortic cross-clamp, and the other had a transient impairment of the hepatic function due to the penetrating hepatic injury and the hypoxic hepatic damage. All 6 survivors were restored to an excellent state of health and had minimal post-resuscitation sequelae. We emphasize the importance of aggressive surgical treatment for those patients with the threat of impending death due to massive hemorrhage from a ruptured great vessel.
Adult↗
Chronic intravascular hemolysis after valvular surgery.
The Phenomenon of intravascular hemolysis following cardiac valvular surgery was studied among 156 randomly selected patients. There were 76 men and 80 women, varying in ages between 15 and 71 years, with a mean age of 48.3 years. The time interval between the study and the operations ranged from 2 to 163 months with a mean of 41.1 months. The prosthetic valve was used in 129 patients; the xenograft tissue valve in 26 and the mechanical valve in 103. Subclinical hemolysis occurred in 68.9% of the 129 patients who had one or more prosthetic valve implants and in 14.8% of the 27 patients who underwent plastic repair of the mitral valve. Compared among the groups with different valve prosthesis, hemolysis could be detected in 81.6% of the patients with a mechanical prosthetic valve and in 23.1% of those with a bioprosthetic tissue valve (p less than 0.05). Twelve patients who had a valve prosthesis were documented to have symptomatic gallstones with an incidence of 9.3%. Among them, only 2 patients had biliary colic and required cholecystectomy to relieve the associated symptom. Anemia, secondary to the hemolysis, occurred in 3.8% of those with a xenograft tissue valve and 8.8% of those with a mechanical valve (p less than 0.05). None of them needed a blood transfusion. None had related renal impairment. In conclusion, the mechanical valve prosthesis has a higher incidence of hemolysis than the xenograft valve. Though the mechanical valve prosthesis has its own merits, the xenograft tissue prosthesis is superior in this respect.
Adolescent↗
Hemolysis following correction of ventricular septal defect.
Hemolysis following repair of a ventricular septal defect (VSD) is an unusual complication. Three cases of patients who had simple VSD are described here. After repair of the VSD, the postoperative course was complicated by the intravascular hemolysis induced by the interaction between the red blood cells and the double velour Dacron patch. Thus the patients' hemodynamic status deteriorated. The first 2 patients had a course of hemoglobinuria, hyperamylasemia, hyperglycemia, malignant hypertension, hepatospenomegaly, acute renal failure and hypertensive encephalopathy. One patient, who did not undergo reoperation, died due to multiple organ failure; the other one, who underwent operation revision in order to arrest the hemolysis, died of sepsis. Early reoperation was performed in the remaining patient to replace the double velour Dacron patch with a pericardium-covered knitted Dacron patch, and he survived. Hemolysis ceased in both patients who had the double velour Dacron patch replaced with a pericardium-covered patch. A review of the literature failed to show previous reports concerned with hemolysis associated with repair of a simple VSD. We now report what we believe to be the first cases in the literature with this unique clinical course following hemolysis.
Blood Vessel Prosthesis↗
[Free amino acid and synthesis of polyamines in Plasmodium-berghei-infected RBC].
The contents of free amino acids and the activity of ornithine decarboxylase in infected RBC of chloroquine-sensitive strain of Plasmodium berghei(CS) were similar to those in chloroquine-resistant strain (CR). After treatment with chloroquine (10mg/kg im) no effect on the formation of free amino acids was found after 20th, but chloroquine (5mg/kg im) inhibited the enzymatic activity of the CS RBC by 79.6% whereas that of the CR by 55.7%. The contents of spermidine in CS and CR infected RBC were found to be 139 +/- 27 and 528 +/- 140 nmol/10(9) infected respectively. Cycloleucine inhibited the formation of spermidine by 44% in CS and 57% in CR groups, while co-administration of methionine (100mg/kg) with cycloleucine (80mg/kg) could reverse the inhibitory effect and raise the contents of spermidine to 294 +/- 56 and 657 +/- 129 nmol/10(9) infected RBC in CS and CR groups respectively. This indicates that methionine had significant effect on the formation of spermidine in CS strain, but there was still a remarkable difference, when compared with CR strain. It is suggested that the activities of S-adenosyl-methionine synthetase and other enzymes involved in polyamine formation might be the causal factors.
Amino Acids↗
Ruptured aneurysms of the sinus of Valsalva in Oriental patients.
Between 1964 and 1987, a total of 57 cases of ruptured aneurysm of the sinus of Valsalva underwent surgical correction at the National Taiwan University Hospital. This represents 0.96% of all cardiac operations. The origin of ruptured aneurysm of the sinus of Valsalva was the right coronary sinus in 46, the noncoronary sinus in nine, and the left coronary sinus in two. The aneurysms ruptured into the right ventricle in 44, into the right atrium in 11, into the left ventricle in one, and into both the right ventricle and right atrium in one. Associated congenital cardiac anomalies included ventricular septal defect in 30 patients, aortic regurgitation in 20, and infundibular pulmonic stenosis and coarctation of the aorta in one each. Operative death occurred in two patients (3.5%) and one patient had a successful reoperation. The remainder did well following surgery. To compare the differences between Oriental and Western countries in ruptured aneurysm of the sinus of Valsalva, 361 cases (195 Oriental patients versus 166 Western) were collected from the literature. Analyses of these cases revealed that ruptured aneurysm of the sinus of Valsalva in Oriental patients compared with Western series is characterized by a higher incidence (5 times), more aneurysms originating from the right coronary sinus (87.9% versus 63.6%), more aneurysm rupturing into the right ventricle (84.2% versus 56.6%), a higher incidence of association with ventricular septal defect (mainly supracristal) (59.0% versus 34.6%), less incidence of association with other congenital cardiac abnormalities (4.1% versus 21.5%), very few instances of rupturing into cardiac chambers other than the right ventricle and right atrium, and less incidence of occurrence in the extremities of ages (the youngest was 7 years in Oriental patients versus 11 months in the Western series). In other words, ruptured aneurysm of the sinus of Valsalva in Oriental patients is more or less a simple and uniform disease entity in contrast to the more diverse and protean pathologic profiles encountered in Western series. However, both Oriental patient and Western patient series have similar incidences of combination with aortic regurgitation (24.6% versus 20.0%), with 40.4% of Oriental patients and 60.6% of Western patients presenting with intact ventricular septum. Therefore the pathogenetic mechanisms of ruptured aneurysm of the sinus of Valsalva may at the same time contribute to the development of aortic regurgitation.
Adolescent↗