To investigate the change in myocardial phospholipids after the administration of isoproterenol and its prevention by pretreatment with phospholipase inhibitors and calcium antagonists, we determined the phospholipid species in the heart of female Wistar rats. Isoproterenol (40 mg/kg) was administered 24 h before excising the heart, and chlorpromazine, mepacrine (phospholipase inhibitors), nifedipine, verapamil (calcium antagonists) and propranolol (beta-adrenoceptor blocker) were injected intraperitoneally 30 min prior to isoproterenol administration. The phospholipid species were quantified using silica gel precoated thin-layer rods and the hydrogen flame ionization method. Isoproterenol induced significant increases in heart/body weight ratio, myocardial protein/heart weight ratio and lysophosphatidylcholine (LPC), and significant decreases in myocardial total phosphorus, creatine kinase (CK) activity, phosphatidylethanolamine and phosphatidylcholine (PC). The significant decrease in PC and increase in LPC indicated the degradation of myocardial phospholipids. Pretreatment with nifedipine (30 mg/kg), verapamil (50 mg/kg) or propranolol (20 mg/kg) completely prevented the occurrence of myocardial injury through the preservation of myocardial phospholipid composition, total phosphorus, CK activity and heart/body and protein/heart weight ratios. On the other hand, chlorpromazine (30 mg/kg) and mepacrine (50 mg/kg) partially prevented myocardial damage through the preservation of myocardial phospholipid composition, total phosphorus and CK activity. Results suggest that not only calcium influx but also phospholipase activation plays an important role in the development of myocardial injury induced by isoproterenol.

Animals↗

PubMedDate not supplied

Alteration in 1,2-diacylglycerol level and its fatty acid composition in hearts during the growth of hamsters.

We measured the amount of 1,2-diacylglycerol (DAG) and its fatty acid composition in hamster hearts of various ages because 1,2-DAG has been recognized to be one of the intracellular second messengers. The highest level in 1,2-DAG was detected in 30-day-old hamster hearts. The heart weight increased about 2.5 times between 30 and 90 days of age. Hamster hearts at 90 days of age had 72% of the 1,2-DAG content at 30 days of age. The amount of 1,2-DAG at 240 days of age was a little lower than that in 90-day-old and 160-day-old hamsters, whereas there was no significant increase in heart weight and only a little gain in body weight between 90 and 240 days of age. The analysis of the fatty acid composition of 1,2-DAG showed an increase in the percentage of 18:0 accompanied by a change in the percentages of other fatty acids with the growth of hamsters. The largest amount of arachidonic acid expressed as 20:4 (n-6) was found at 30 days of age. On the other hand, triglyceride, cholesterol, and major phospholipid components of hamster hearts increased in accordance with growth. In particular, the increase in triglyceride content was remarkable, indicating that myocardial lipidosis may be induced by aging. These results demonstrate that 1,2-DAG may be involved in the synthesis of protein during heart growth and that the alteration of its fatty acid composition is related to the growth of hamsters.

Animals↗

PubMedDate not supplied

1,2-diacylglycerol content in myocardium from spontaneously hypertensive rats during the development of hypertension.

1,2-Diacylglycerol (DAG) has been considered to play an important role as an activator of protein kinase C in the signal transduction of inositol phospholipid metabolism. To examine the relation of 1,2-DAG in heart tissues to cardiac hypertrophy associated with hypertension, we measured the amount of 1,2-DAG in spontaneously hypertensive rat (SHR) hearts at 4, 10 and 20 weeks of age, and in age-matched normotensive Wistar-Kyoto (WKY) rat hearts using thin-layer chromatography with flame ionization detection (TLC-FID). Significant cardiac hypertrophy was found in 4-week-old SHR, while SHR did not yet have significant hypertension. Major phospholipids such as phosphatidylcholine and phosphatidylethanolamine increased from 4 to 20 weeks in the myocardium, but there was no difference between the two strains. The cholesterol levels of 4- and 20-week-old SHR were significantly higher than WKY rats. The 1,2-DAG contents of SHR hearts were significantly higher than WKY rats at 4 weeks. An increase in the RNA content was also observed in 4-week-old SHR hearts. However, analysis of the fatty acid composition of 1,2-DAG revealed no difference between the two strains. However, there was no significant difference in the 1,2-DAG content or in its fatty acid composition between SHR and WKY rat hearts at 10 and 20 weeks of age. It is suggested that an increase in the 1,2-DAG content of SHR hearts during the early stages appears related to the initiation of cardiac hypertrophy in SHR hearts before developed hypertension.

Aging↗

PubMedDate not supplied

Lipid metabolism in perfused human nonatherosclerotic coronary arteries and saphenous veins.

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Acetates↗

PubMedDate not supplied

A study on the release mechanism of vasopressin and oxytocin.

The changes in plasma levels of arginine-vasopressin (AVP) and oxytocin (OXT) of rabbits by intraventricular administration of various drugs and their effects on the release of both hormones from the isolated posterior pituitary of rats were examined. An intraventricular injection of hypertonic saline, carbachol, angiotensin II, prostaglandin E2 or histamine to a rabbit increased the concentrations of plasma AVP and OXT, whereas serotonin decreased their plasma levels. Noradrenaline increased the concentration of OXT, but not that of AVP. Dopamine did not significantly affect the plasma level of either hormone. The release of AVP and OXT from the posterior pituitary fragments of rats was stimulated by changing the osmolality of the perfusion medium in vitro. Perfusion with medium containing dopamine suppressed the release of both hormones. However, the other bioactive amines and the drugs mentioned above did not affect the release of AVP and OXT.

Angiotensin II↗

PubMedDate not supplied

Biorhythm of arginine- vasopressin in the paraventricular, supraoptic and suprachiasmatic nuclei of rats.

The diurnal variations in content of arginine-vasopressin in the supraoptic nucleus, the paraventricular nucleus and the suprachiasmatic nucleus of rats were determined using radioimmunoassay. In the supraoptic nucleus and the paraventricular nucleus the arginine-vasopressin level was relatively constant during the light phase (the inactive phase). When it became dark, the level of arginine-vasopressin lowered during the early and middle dark phase and then increased to the highest level during the late dark phase. In the suprachiasmatic nucleus the level was stable during the light phase, while in the early and the late dark phase it was significantly higher than that in the middle dark phase.

Animals↗

PubMedDate not supplied

Characteristics of hepatocytes derived from early ES cells and treatment of surgically induced liver failure rats by transplantation.

BACKGROUND: Although liver transplantation has become a standard therapy for diseases such as fulminant hepatitis and cirrhosis, the lack of donor organs remains a major problem. One solution is the development of transplantable hepatocytes. The metabolic characteristics as well as function and adaptation of hepatocytes (R-EES-hep cell) derived from rat early embryonic stem cells were examined after transplantation into rats with surgically induced liver failure. METHODS: Rat hepatocyte cell lines were established from early embryonic stem cells cultured in the presence of embryotrophic factors by colony cloning methods. The cell lines were established from two cell embryos taken from spontaneous dwarf rats using the novel method of Ishiwata et al. Morphologic differentiation as well as albumin and bilirubin production were observed by immunostaining. R-EES-hep cells were transplanted into the spleens of 90% hepatectomized, surgically induced liver failure rats to analyze survival rates. RESULTS: When cultured in type I collagen gel the cells formed cordlike structures resembling the liver. Both albumin and bilirubin production were observed when transplanted; the spleen was converted into a liver-like structure with prolonged survival of the 90% hepatectomized rats for up to 3 months up to the time of killing. CONCLUSIONS: R-EES-hep cells showed many of the distinctive metabolic characteristics of the liver. These cells may be efficient for further research and application for hepatic cell transplantation to treat liver insufficiency patients and as biologic artificial organs.

Animals↗

PubMedDate not supplied

Pentosidine and autofluorescence in lenses of diabetic patients.

Pentosidine, an advanced glycation endproduct, may cause the increased fluorescence found in the lenses of diabetic patients. We measured the autofluorescence in human lenses, in vitro, and quantified the pentosidine to examine its relationship to the autofluorescence. Lens autofluorescence was higher in diabetic than non-diabetic subjects; pentosidine quantities were significantly higher in the diabetic than the non-diabetic group indicating that pentosidine was involved in the greater intensity of autofluorescence in the lenses of patients with diabetes mellitus.

Aged↗

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Insertion of intradermal needles into painful points provides analgesia for intractable abdominal scar pain.

BACKGROUND AND OBJECTIVES: Conventional treatments are often ineffective for patients having painful abdominal scars. There are painful points in and around scar tissue. We tested the hypothesis that insertion of intradermal needles into these painful points reduces scar pain. METHODS: Patients with abdominal scar pain with painful points that is not relieved by conventional treatments were allocated to a treatment group (n = 23), a sham-treatment group (n = 23), or a control group (n = 24). In the treatment group, intradermal needles were inserted into painful points detected by a pressure threshold meter (pain < or = 2.5 kg/cm(2)). In the sham-treatment group, the same needles were inserted into nonpainful points. The needles were kept in place for 24 hours. This process was repeated 20 times over a 4-week period. Responses were evaluated before and at the end of treatment, and 4 and 26 weeks after the treatment. Continuous and lancinating pain was evaluated on a 10-cm visual analog scale. We measured the area of pain and the pressure required to initiate painful-point pain. All patients took diclofenac as needed and completed a diary of daily diclofenac consumption. RESULTS: Patients in the treatment group showed a marked reduction in all pain parameters (>70%). In contrast, analgesia was minimal in the other groups. The decreases in the pain threshold pressure correlated with the decreases in continuous and lancinating pain (r =.57 and r =.63, respectively). CONCLUSION: Our data suggest that insertion of intradermal needles into painful points is a remarkably effective treatment for intractable abdominal scar pain. Analgesia presumably results from inactivation of painful points, through a yet to be elucidated mechanism.

Abdomen↗

PubMedDate not supplied

The effect of methotrexate (MTX) on expression of signalling lymphocytic activation molecule (SLAM) in patients with rheumatoid arthritis (RA) and its role in the regulation of cytokine production.

OBJECTIVE: To investigate the effect of methotrexate (MTX) on cytokine production by activated CD4+ T-cells in patients with rheumatoid arthritis (RA). METHODS: The effect of MTX on intracellular expression of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), and cell surface expression of signalling lymphocytic activation molecule (SLAM) from freshly isolated peripheral blood mononuclear cells (PBMCs), and after in vitro culture with or without MTX, was analysed with flow cytometry in 18 patients with RA and 20 healthy controls. RESULTS: Intracellular expression of IFN-gamma and IL-4 on freshly isolated CD4+ T-cells was significantly higher in patients with RA than in the controls (p<0.05). Intracellular expression of both IFN-gamma and IL-4 after culture with MTX was significantly lower than those after culture without MTX in patients with RA. Although no significant difference was observed in SLAM expression on freshly isolated CD4+ T-cells between patients with RA and the controls, MTX significantly decreased SLAM expression on both activated IFN-gamma+ and IL-4+CD4+ T-cells in patients with RA. CONCLUSION: In vitro modulation of the cytokine network by MTX, IFN-gamma, and IL-4 is one of the major targets for MTX, and production of IFN-gamma and IL-4 by PBMCs may be suppressed by SLAM on activated CD4+ T-cell in patients with RA.

Aged↗

PubMedDate not supplied

Computed tomography of ovarian masses.

A retrospective analysis of CT images in 138 histologically proven ovarian masses in 100 patients was undertaken to evaluate the usefulness and limitation of CT in the diagnosis of ovarian tumors. Benign masses were purely cystic in 98 (94.2%) and had solid component (including thickened walls, thickened septa, papillary projections) in five of 104 lesions (4.8%) on CT. These five masses, which are classified as benign solid tumors, could not be differentiated from malignant tumors by either the size of the solid portion or the intensity of contrast enhancement. In the malignant tumors a solid portion was detected in 32 of 34 tumors (94%). When a solid component is detected in an ovarian mass, the mass should be considered malignant although a few cases will be benign solid tumors. In Krukenberg tumors, which were all of gastric origin, the solid component was so large that it occupied more than one-half the mass. Therefore, if the solid portion of the ovarian mass is large on CT, upper gastrointestinal study should be performed to rule out Krukenberg tumor.

Diagnosis, Differential↗

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Intramuscular solitary fibrous tumor: a clinicopathological case study.

We present a case of extrapleural solitary fibrous tumor arising within the muscle, an unusual and hitherto-undescribed tumor lesion. A 42-year-old woman presented a painless mass in her left thigh. The lesion was depicted as an intramuscular mass that enhanced on both CT and MRI, showing quite rich tumor vascularity. The histological features of the tumor were spindle cell proliferation with various histological patterns, typical fibrocollagenous background, and positive immunoreactivity for CD-34.

Adult↗

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Effects of commonly used cardioactive drugs on atrial and sinoatrial conduction in man.

Atrial and sinoatrial conduction intervals were measured in patients before and after the intravenous administration of one of four cardioactive drugs: procainamide, atropine, ouabain, and propranolol. Procainamide uniformly prolonged atrial conduction and shortened sinoatrial conduction. Atropine also shortened sinoatrial conduction but did not significantly alter atrial conduction. Ouabain prolonged sinoatrial conduction in patients with normal control sinoatrial conduction intervals and did not affect atrial conduction. Propranolol did not significantly alter sinoartrial conduction and only prolonged interatrial conduction in patients with normal base line atrial conduction intervals. Of the cardioactive drugs tested, only procainamide and propranolol significantly altered the atrial conduction intervals; furthermore, the effects of these cardioactive drugs on sinoatrial conduction were disparate from their effects on atrial conduction.

Adult↗

PubMedDate not supplied

Effects of nicardipine, a dihydropyridine calcium antagonist, on regional myocardial blood flow, myocardial oxygen tension, and electrical abnormalities during acute coronary artery occlusion in dogs.

Effects of nicardipine, a dihydropyridine calcium antagonist, on regional myocardial blood flow (RMBF), myocardial oxygen tension (PO2), and excitation and conduction abnormalities during the occlusion of the left anterior descending coronary artery (LAD) were examined in anesthetized dogs, and compared with those of nifedipine and dipyridamole. RMBF was calculated from the H2 gas clearance curves, and PO2 was measured using a membrane-coated Pt wire. Excitation and conduction abnormalities during the LAD occlusion were represented in terms of the degree of ST-T alternans (STTA), TQ depression, and conduction delay, which appeared in epicardial electrograms. Nicardipine and nifedipine in a dose of 10 micrograms/kg increased RMBF and PO2 levels in nonischemic and mildly ischemic tissues, but not in severely ischemic tissues. Nicardipine in a dose of 100 micrograms/kg and nifedipine in a dose of 10 micrograms/kg attenuated the degree of STTA, TQ depression, and conduction delay observed in severely ischemic tissues. In mildly ischemic tissues where only TQ depression was observed without STTA, nicardipine in a dose of 30 micrograms/kg attenuated TQ depression. Dipyridamole in a dose of 1 mg/kg produced only a slight attenuation of STTA and conduction delay. These results suggest that the beneficial effects of nicardipine as well as of nifedipine on myocardial ischemia are due to the increase in the myocardial PO2 levels caused by the increased RMBF and also to direct protecting effects on ischemic myocardial cells. In the severely ischemic tissues, the latter is a main effect of the drugs. In increasing the PO2 level, nicardipine was similarly potent as nifedipine, but in the direct effect, nicardipine was less potent, and dipyridamole was almost ineffective.

Animals↗