Dietary effect of a symmetrical triacylglycerol, 1,3-biseicosapentaenoyl-2-γ-linolenoyl glycerol, on fatty acid composition of guinea pigs

The dietary effect of 1,3-biseicosapentaenoyl-2-γ-linolenoyl glycerol (STG) on the fatty acid composition of guinea pigs was examined and compared with that of an eicosapentaenoic acid ethyl ester (EPA-F) and of a soybean oil (SBO) diet. In terms of content of plasma lipid, EPA-E had a greater hypolipidemic effect than STG. On the other hand, in terms of EPA incorporation, contents of EPA in liver lipid were almost the same in the STG and EPA-E groups. Considering that the amount of EPA administered in the EPA-E group was almost 1.5 times that of the STG group, FPA may be absorbed more effectively as the glycerol ester than as the ethyl ester in guinea pigs. In all the tissue lipids, the STG group had a higher unsaturation index (UI) than the EPA-E group even though there is a lower UI in the STG diet than the EPA-E diet. These results suggest that greater amounts of desaturase products as a whole were synthesized in the STG group than in the other two groups. The dihomo-γ-linolenic acid/arachidonic acid (DGLA/AA) ratio in plasma total lipids in the STG group was 3.5 times that of SBO group, and the DGLA/AA ratio in the EPA-E group was half that of the SBO group. In liver lipid, the ratios of DGLA/AA and EPA/AA in the STG group were 0.687 and 0.488 (phosphatidylcholine fraction) and 0.237 and 0.752 (phosphatidylethanolamine fraction), respectively. The ratio of DGLA/AA as well as the high EPA/AA ratio obtained in the present study with the STG diet may lead to physiological alterations, including enhanced synthesis of 1-and 3-series eicosanoids.     

Radiation doses to neonates during X ray computed tomography examinations

As the survival rate of newborns has increased, the number of X ray computed tomography (CT) examinations performed on neonates has been increasing. The exposure doses from CT examinations are known to be higher than those from conventional radiography. Although radiation sensitivity of neonates is higher than that of adults, there are few reports on dose estimates of neonates in CT examinations. Four cylindrical phantoms and one neonatal phantom have been developed to estimate doses to neonates during CT examinations. Using these phantoms and glass dosemeters, absorbed doses were measured. Estimated exposure doses to neonates were higher than those to adults, and our results suggest a need to optimise carefully CT examinations in newborns.     

Species differences in brain adenosine A1 receptor pharmacology revealed by use of xanthine and pyrazolopyridine based antagonists

1. The pharmacological profile of adenosine A1 receptors in human, guinea-pig, rat and mouse brain membranes was characterized in a radioligand binding assay by use of the receptor selective antagonist, [3H]-8-cyclopentyl-1,3-dipropylxanthine ([3H]-DPCPX). 2. The affinity of [3H]-DPCPX binding sites in rat cortical and hippocampal membranes was similar. Binding site affinity was higher in rat cortical membranes than in membranes prepared from guinea-pig cortex and hippocampus, mouse cortex and human cortex. pKD values (M) were 9.55, 9.44, 8.85, 8.94, 8.67, 9.39 and 8.67, respectively. The binding site density (Bmax) was lower in rat cortical membranes than in guinea-pig or human cortical membranes. 3. The rank order of potency of seven adenosine receptor agonists was identical in each species. With the exception of 5'-N-ethylcarboxamidoadenosine (NECA), agonist affinity was 3.5-26.2 fold higher in rat cortical membranes than in human and guinea-pig brain membranes; affinity in rat and mouse brain membranes was similar. While NECA exhibited 9.3 fold higher affinity in rat compared to human cortical membranes, affinity in other species was comparable. The stable GTP analogue, Gpp(NH)p (100 microM) reduced 2-chloro-N6-cyclopentyladenosine (CCPA) affinity 7-13.9 fold, whereas the affinity of DPCPX was unaffected. 4. The affinity of six xanthine-based adenosine receptor antagonists was 2.2-15.9 fold higher in rat cortical membranes compared with human or guinea-pig membranes. The rank order of potency was species-independent. In contrast, three pyrazolopyridine derivatives, (R)-1-[(E)-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl) acryloyl]-2-piperidine ethanol (FK453), (R)-1-[(E)-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl) acryloyl]-piperidin-2-yl acetic acid (FK352) and 6-oxo-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-1(6H)-pyridazinebutyric acid (FK838) exhibited similar affinity in human, guinea-pig, rat and mouse brain membranes. pKi values (M) for [3H]-DPCPX binding sites in human cortical membranes were 9.31, 7.52 and 7.92, respectively. 5. Drug affinity for adenosine A2A receptors was determined in a [3H]-2-[4-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamido ade nosine ([3H]-CGS 21680) binding assay in rat striatal membranes. The pyrazolopyridine derivatives, FK453, FK838 and FK352 exhibited pKi values (M) of 5.90, 5.92 and 4.31, respectively, compared with pKi values of 9.31, 8.18 and 7.57 determined in the [3H]-DPCPX binding assay in rat cortical membranes. These novel pyrazolopyridine derivatives therefore represent high affinity, adenosine A1 receptor selective drugs that, in contrast to xanthine based antagonists, exhibit similar affinity for [3H]-DPCPX binding sites in human, rat, mouse and guinea-pig brain membranes.     

Dose measurement for medical staff with glass dosemeters and thermoluminescence dosemeters during 125I brachytherapy for prostate cancer

Photoluminescence glass dosemeters (PLDs) and thermoluminescence dosemeters (TLDs) are commonly used as a personal monitoring dosemeter. PLDs and TLDs were used for surface dose monitoring of medical staff involved in (125)I brachytherapy for prostate cancer because these dosemeters have a wide dose-response linearity and high sensitivity for low photon energy. Surface doses measured with PLDs agreed with those with TLDs within ～20 % except for a few cases. Surface doses at a surgeon's left hand and arm were higher than those at the other measuring points. A surgeon received a maximum dose of 650 μGy at the back of left hand. Surface doses to an assistant were <100 μGy. Surface doses to a nurse, a radiologist, an anaesthesiologist and a radiological technologist were <10 μGy. The occupational exposure to a surgeon could be reduced by the adjustment of fluoroscopic parameters and the use of lead gloves.     

Effect of KSG-504, a new CCK-A-receptor antagonist, on experimental acute pancreatitis in rats and mice

We investigated the protective and/or therapeutic effects of a new cholecystokinin receptor antagonist, KSG-504, on different types of experimental pancreatitis in the rat and mouse. The intravenous injection of KSG-504 (10, 25, 50 and 100 mg/kg) before caerulein administration to the rat inhibited the increases in plasma amylase, lipase and of pancreatic wet weight in a dose-dependent manner. The histological changes due to caerulein-induced acute pancreatitis were also decreased by KSG-504 when KSG-504 (25, 50 and 100 mg/kg) was administered after the induction of acute pancreatitis; the increases in plasma amylase, lipase and pancreatic wet weight were reduced, but the histological changes of the pancreas were not decreased significantly. In the second experiment, acute pancreatitis was induced in rats by injecting 0.3 ml of 6% sodium taurocholate into the pancreatic interstitial tissue. KSG-504 administered immediately and 1.5 hr after sodium-taurocholate injection at 100 mg/kg reduced the increases of pancreatic enzymes in the plasma, pancreatic wet weight and ascites. Moreover, KSG-504 (50 and 100 mg/kg, i.v., x 2) mitigated the histological changes of taurocholate-induced acute pancreatitis. Another type of acute pancreatitis was induced in mice by dl-ethionine (0.5 g/kg, p.o., x 4) and a choline-deficient diet. KSG-504 (10, 30 and 100 mg/kg) was subcutaneously administered five times every 12 hr during the experiment. KSG-504 elongated the survival of mice in a dose-dependent manner. These findings suggest that KSG-504 has potent protective and/or therapeutic effects against acute pancreatitis and that cholecystokinin may be involved in the development of pancreatitis.     

Pharmacological characterization of a simple behavioral response mediated selectively by central adenosine A1 receptors, using in vivo and in vitro techniques

Mouse embryonic carcinoma P19 cell aggregates treated with retinoic acid (RA) sequentially differentiate into neurons and astrocytes, whereas attached cells develop a mesodermal phenotype. The expression of calcitonin (CT) and PTH/PTH-related protein (PTHrP) receptors was investigated in embryonic cells, and during neural and mesodermal differentiation. In embryonic P19 cells, specific binding of [125I]salmon (s) CT(1-32) ([125I]sCT(1-32)) was 56 fmol/mg protein, and of [125I]chicken (ch) [Tyr36]PTHrP(1-36) amide ([125I]chPTHrP(1-36)) < 0.5 fmol/mg protein. Correspondingly, cAMP was maximally stimulated 47-fold by sCT(1-32) (EC50 0.05 nM) and 3-fold by chPTHrP(1-36) (EC50 1.3 nM). Receptor autoradiography revealed specific binding of [125I]sCT(1-32) to the undifferentiated P19 cells, but not to RA induced neurons and astrocytes. At the same time, [125I]sCT(1-32) binding and cAMP accumulation by sCT were gradually decreased. But, specific binding of [125I]chPTHrP(1-36) was raised at least 6-fold compared with embryonic cells to 3 fmol/mg protein, in parallel with a 10-fold higher maximal cAMP accumulation. A similar, but delayed suppression of CT and stimulation of PTH/PTHrP receptor expression was observed during mesodermal cell differentiation. The results indicate that CT receptors are associated with undifferentiated P19 cells, whereas PTH/PTHrP receptors are expressed in RA induced neural and mesodermal cells.     

Over 1.3 /spl mu/m CW laser emission from InGaSb quantum-dot vertical-cavity surface-emitting laser on GaAs substrate

An Sb-based quantum-dot vertical-cavity surface-emitting laser (QD-VCSEL) operating in the 1.3 /spl mu/m optical communication waveband is presented. A QD-VCSEL containing high-density InGaSb QDs in the active region is fabricated on GaAs substrate. The density of InGaSb QDs is drastically increased using a new method of an Si atom irradiation technique. A long-wavelength laser emission at 1.34 /spl mu/m is successfully achieved on the InGaSb QD-VCSEL in CW operation at room temperature.     

Effects of Nd:YAG laser irradiation on morphometry and lung function in elastase-induced emphysema in rats

BACKGROUND & OBJECTIVE: Although thoracoscopic laser ablation therapy has been hailed as an effective surgical treatment for diffuse emphysema, no one has as yet made an in-depth study of the efficacy of this treatment. This investigation was undertaken to research the effects of laser pneumoplasty on an animal model of emphysema. STUDY DESIGN/MATERIALS AND METHODS: Eight weeks after elastase treatment, the rats' left lungs were irradiated using contact Nd:YAG laser. Pulmonary function tests were performed 4 weeks after irradiation and the lungs were prepared for histologic examination. RESULTS: Dense fibrous scars beneath the pleura were observed at 4 weeks after irradiation. Although mean linear intercept values of irradiated lungs were not much lower than those in the non-irradiated elastase-treated group, laser irradiation caused a significant decrease in lung volume. While there was no significant difference in quasistatic compliance, elastic recoil pressure of the lung increased to control levels at total lung capacity volume. CONCLUSION: We conclude that laser therapy does not cause normalization of compliance, or improvement in the deeper part of the emphysematous lung, but rather a peripheral volume reduction and "encasement effect" on the lungs as a result of fibrotic scars.     

Progress in instrument used for diagnosis of obstructive jaundice. 4. MRCP

OBJECTIVE: The objective of the study was to determine the prevalence and associations of abnormal alpha1-antitrypsin phenotypes in Caucasian adults with end stage liver disease with particular emphasis on heterozygous phenotypes and disease from hepatitis C virus. METHODS: All patients (788) with end stage liver disease considered for liver transplantation from July 1990 to June 1996 in a referral-based university hospital transplant center (University of Nebraska Medical Center, Omaha, NE) comprised the study population. Data for the study population was determined by retrospective review of the transplantation database at the transplant center. Hepatitis C virus infection was determined by a second generation ELISA method, and alpha1-antitrypsin phenotyping was performed on agarose gel with serum quantitation using a Behring Nephelometer. RESULTS: Among 683 Caucasian patients with severe liver disease, the prevalences of Pi ZZ, Pi MZ, and Pi MS were 0.4, 7.3, and 8.2%, respectively, compared with 0, 2.8, and 4.2% in the control population. The odds of having a heterozygous Z phenotype were significantly increased in Caucasian patients with hepatitis C virus (odds ratio (OR) = 4.3, 95% confidence interval (CI) = 2.1-9.0), alcoholic liver disease (OR = 5.0, 95% CI = 2.6-9.6), primary hepatic malignancy (OR = 7.4, 95% CI = 2.9-19.0), and cryptogenic cirrhosis (OR = 2.6, 95% CI = 1.1-6.3) compared with the control population. Caucasian patients with hepatitis C or B virus were 3.6 times more likely to have a heterozygous Z phenotype than a normal phenotype compared with patients with diseases of autoimmune etiology. CONCLUSION: This study provides evidence of an association of heterozygous Z alpha1-antitrypsin phenotype with end stage liver disease of several etiologies, not hepatitis C virus alone.