Vitamin E deficiency intensifies the myocardial injury of coxsackievirus B3 infection of mice

Feeding a vitamin E-deficient diet increases pathology in hearts of mice infected with a myocarditic coxsackievirus B3 (CVB3/20). Hearts from infected mice fed a vitamin E-deficient diet rich in highly unsaturated fat (menhaden oil) exhibited more severe pathology than hearts from infected mice fed a vitamin E-deficient diet based largely on saturated fat (lard). Furthermore, a cloned and sequenced amyocarditic coxsackievirus B3 (CVB3/0), which caused little or no pathology in the hearts of vitamin E-supplemented mice, induced extensive cardiac pathology in vitamin E-deficient mice. In infected mice, both mitogen and antigen responses were depressed by vitamin E deficiency, although neutralizing antibody responses were unaffected. Natural killer cell responses were comparable in infected mice fed a lard-based diet with or without supplemented vitamin E. However, a menhaden oil-based diet, whether supplemented with vitamin E or not, significantly depressed natural killer cell activity in infected mice compared with mice fed the lard-based diet. Coxsackievirus B3/0 recovered from the heart of a vitamin E-deficient donor mouse, passaged one time onto HeLa cells, caused significant heart damage when passed back into vitamin E-supplemented recipient mice, demonstrating that the amyocarditic CVB3/0 had changed to a virulent phenotype. Enhanced virulence was also seen with CVB3/20 virus similarly passaged in a vitamin E-deficient donor. Our work demonstrates the important role of host nutritional antioxidant status in determining the severity of certain viral infections.

Anti-AIDS agents, 10. Acacetin-7-O-beta-D-galactopyranoside, an anti-HIV principle from Chrysanthemum morifolium and a structure-activity correlation with some related flavonoids

An active anti-HIV principle, acacetin-7-O-beta-D-galactopyranoside, has been isolated from Chrysanthemum morifolium. Seven additional flavonoids isolated from this plant, 13 known related flavonoids, and 14 synthetic flavonoids were also evaluated as inhibitors of HIV replication in H9 cells. A known flavone, chrysin, was found to be the most promising compound in this series. Flavonoids with hydroxy groups at C-5 and C-7 and with a C-2-C-3 double bond were more potent inhibitors of HIV growth. In general, the presence of substituents (hydroxyl and halogen) in the B-ring increased toxicity and/or decreased activity.

Impact of regional ventricular function, geometry, and dobutamine stress on quantitative 99mTc-sestamibi defect size

BACKGROUND

Serial myocardial perfusion imaging with 99mTc-sestamibi (MIBI) was used to evaluate infarct risk area and salvage after thrombolysis. The purpose of this investigation was to determine whether changes in MIBI defect size observed after reperfusion may result in part from distortion of regional and global left ventricular geometry.

METHODS AND RESULTS

Twenty-five open-chest dogs were subjected to either 15 minutes (groups 1A and 1B) or 3 hours (group 2) of left anterior descending coronary artery occlusion followed by 3 hours of reperfusion. MIBI was injected before occlusion (group 1A) or during occlusion (groups 1B and 2), and serial ECG-gated planar imaging was performed. Dobutamine was infused after 3 hours of reperfusion (groups 1B and 2) to transiently alter left ventricular size and function. Perfusion defect magnitude (DM) and extent (DE) were serially quantified with circumferential profile analysis of end-systolic (ES), end-diastolic (ED), and summed images. Flow was assessed with radiolabeled microspheres and correlated with myocardial MIBI activity. Myocardial thickening was assessed in the risk area with sonomicrometers. In group 1A dogs, ischemic dyskinesis produced large artifactual quantitative MIBI defects on ES images (DM, 9.3 +/- 1.3; DE, 27.8 +/- 6.0) that were significantly smaller on ED images (DM, 4.5 +/- 0.9, P < .05; DE, 4.4 +/- 2.3, P < .05). In addition, DM and DE correlated inversely with myocardial thickening on ES images (DM, r = -.84; DE, r = -.78) and summed images (DM, r = -.72; DE, r = -.61) but not ED images (DM, r = -.12; DE, r = -.15). An index of defect reduction derived from summed images correlated well with thickening fraction in stunned dogs (group 1B, r = .89) but poorly in infarcted dogs (group 2, r = .41) subjected to dobutamine stress.

CONCLUSIONS

99mTc-MIBI defect size may be affected by alteration of left ventricular geometry. Changes in regional function may confound analysis of risk area and myocardial salvage with serial 99mTc-MIBI imaging and may also affect defect size during pharmacological stress with dobutamine. Dobutamine 99mTc-MIBI imaging may be useful for distinguishing viable and nonviable myocardium.

The direct effect of graft compliance mismatch per se on development of host arterial intimal hyperplasia at the anastomotic interface

To study the direct and sole effect of compliance mismatch on anastomotic intimal hyperplasia of the host arterial wall and to minimize possible confounding factors, dogs with a low thrombotic potential were selected as experimental subjects. Externally supported 6 cm x 5 mm Dacron grafts with a compliance value of approximately 1/300 of the host artery were implanted into the carotid arteries with end-to-end anastomoses on one side and end-to-side anastomoses on the other. The control graft was an autogenous carotid artery segment 4 cm in length transplanted into the femoral artery. Eight cases (24 grafts) were studied for 1 year and three (nine grafts) for 6 months. All were patent throughout the study period except for two noncompliant grafts with end-to-end anastomoses; thrombosis was the documented cause of occlusion. For the patent grafts, follow-up arteriograms showed no progressive narrowing of noncompliant anastomoses. Whether compliant or noncompliant, light microscopy studies showed slight intimal thickening within 1 to 2 mm of the anastomotic line, possibly the result of the normal healing response to stitch and surgical trauma. Quantitatively, 22 measurements representing longitudinal and circumferential thickness of the neointima were taken at each of the 40 patent noncompliant and 22 patent compliant control anastomoses. There was no statistically significant difference in anastomotic neointimal thickness in compliant and noncompliant grafts or for the different implantation periods. These data suggest that graft/host artery compliance mismatch does not cause arterial intimal hyperplasia at the anastomotic interface.

Cytoplasmic accumulation of a normally mitochondrial malonyl-CoA decarboxylase by the use of an alternate transcription start site

Malonyl-CoA decarboxylase, a normally mitochondrial enzyme, accumulates in the cytoplasm of specialized glands to cause production of multiple methyl-branched fatty acids. Evidence was presented that a single copy of the decarboxylase gene present in the goose genome codes for both the mitochondrial form found in extremely low amounts in the liver and the cytosolic form found in large amounts in uropygial glands. To elucidate how a single gene encodes both forms, the malonyl-CoA decarboxylase gene and the cDNAs for both the mitochondrial (liver) and the cytoplasmic (gland) species were cloned and sequenced. The decarboxylase gene, found in a 21-kb segment of cloned genomic DNA, is composed of five exons of 0.521, 0.118, 0.156, 0.145, and 1.93 kb interrupted by 6.9, 1.5, 0.45, and 9.3-kb introns. Exon 1 revealed two ATGs in frame 150 bp apart. cDNA for the cytoplasmic form and mitochondrial form showed identical nucleotide sequence, except that the latter was longer than the former. The longest cDNA for the cytoplasmic form of the enzyme extended only 44 bp 5' to the second ATG and the position corresponded to the transcription initiation site of the cytoplasmic form revealed by primer extension and RNase protection. The cDNA for the mitochondrial form isolated from the library extended 19 bp further upstream. Primer extension and RNase protection indicated that transcripts for the mitochondrial form initiated upstream from the first ATG. The N-terminal segment of the open reading frame initiated at the first ATG showed an amphipathic signal sequence appropriate for mitochondrial import. A putative full length mRNA for the mitochondrial form of the enzyme when translated in vitro yielded a 55-kDa primary translation product which was processed by removal of about 5 kDa during uptake into goose liver mitochondria. These results strongly suggest that in most tissues transcription initiates 5'- to the first ATG, generating a transcript that would generate a protein with an N-terminal leader for transport into mitochondria. In the uropygial gland the use of an alternate promoter generates transcripts initiated between the two ATGs and the translation product accumulates in the cytoplasm since it lacks a mitochondrial targeting sequence.

Analysis of the upstream regulatory region of human ventricular myosin light chain 1 gene

To explore the mechanisms regulating expression of ventricular myosin light chain 1, the human gene including 5'-flanking DNA was cloned and characterized by Southern blot and restriction mapping. A 2 kb 5'-flanking DNA was sequenced and linked to a chloramphenicol acetyltransferase reporter gene. The constructs then were transfected into cultured human and rat cardiomyocytes as well as rat aortic endothelial cells. Deletion analysis of constructs revealed that the basal promoter sequences, which were located within 62 base pairs of the cap site, could direct high levels of chloramphenicol acetyltransferase gene expression in the cardiomyocytes and endothelial cells. The region between -62 to -312 base pairs strongly repressed the chloramphenicol acetyltransferase gene expression in the cardiomyocytes and endothelial cells. Positive elements were found between -312 and -2000 base pairs of the cap site. These results are indicative, among other possibilities, that the human ventricular myosin light chain 1 gene is turned on in cardiomyocytes by the presence of trans-acting factors that are bound to upstream positive elements and is turned off in non-muscle cells by the presence of repressor-binding proteins. But this mechanism remains to be established.

Electron microscopic study of (A)BC excinuclease. DNA is sharply bent in the UvrB-DNA complex

Nucleotide excision repair in Escherichia coli is initiated by the UvrA, UvrB and UvrC proteins. UvrA is the damage recognition subunit, makes an A2B1 complex with the targeting subunit UvrB, and the complex binds to the lesion site; UvrA dissociates leaving behind a very stable UvrB-DNA complex that is recognized by the trigger subunit, UvrC, and the ensuing UvrB-UvrC heterodimer makes two incisions, one on either side of the lesion. Using electron microscopy, we investigated the structures of these early A, A-B intermediates on DNA containing ultraviolet light photoproducts. UvrA, which is known to bind to DNA as a dimer and produce a DNase I footprint of 33 base-pairs does not change the trajectory of DNA appreciably. The A2B1 complex clearly shows a bipartite structure and its effect on the trajectory of the DNA was not consistently straight or kinked. In contrast, the DNA in the preincision UvrB-DNA complex appears to be severely kinked; 43% of the molecules are bent by 80 degrees or more, with an average bending angle of 127 degrees. It appears that protein-induced bending is an important step on the pathway leading to excision of the damaged nucleotide by (A)BC excinuclease.

[Chemical components of the leaves of Pistacia Chinensis Bge]

Six compounds have been isolated from the leaves of Pistacia chinensis, a species of Anacardiaceae family. Their structures were identified on the basis of UV, IR, NMR, and MS as gallic acid, m-digallic acid, quercetin, 6-0-galloyl arbutin-quercitrin and quercetin-3-0(6''-galloyl)-beta-D-glucosides.

Experimental evaluation of ten clinically used arterial prostheses

The arterial grafts currently in use are classified into five basic categories; 10 different commercially available prostheses were chosen to represent these categories. The Vascutek and Bionit are made from knitted Dacron and have medium porosity, requiring preclotting by the surgeon. The DeBakey Soft Woven and Plasma TFE grafts are made from woven Dacron and have low porosity, not requiring preclotting under most circumstances. Also studied were woven and knitted grafts with leakage resistance referred to as "impervious" Dacron grafts: the Vascutek Gelseal, the Bard Albumin Coated DeBakey Vasculour II, the Microvel with Hemashield, and the albumin saturated, autoclaved DeBakey Soft Woven graft. Gore-Tex and Impra are expanded polytetrafluoroethylene grafts which do not require preclotting. For each type, five grafts 6 cm long and 8 mm in diameter were implanted in the descending thoracic aorta of healthy adult dogs for 16 weeks. The physical characteristics, biocompatibility, and healing patterns varied according to the structure and treatment of the grafts. Pretreatment with biomaterials during manufacture is quite effective in preventing transinterstices blood loss during implantation, but results in altered physical qualities, increased thrombogenicity and delayed healing in comparison to the effects of preclotting with autogenous blood at the time of implantation.

An endodermal sinus tumor in the cerebellopontine angle

Immunohistochemical and ultrastructural findings in a primary intracranial endodermal sinus tumor are reported in this paper. The tumor cells exhibited AFP, CEA and anti-alpha-1-trypsin positive immunoreactivity immunocytochemically. Aggregates of electron-dense material in the extra- and intracellular spaces and amorphous basement membrane-like substance were seen extracellularly by electron microscopy. The clinicopathological, immunocytochemical and ultrastructural features were consistent with the criteria for primary intracranial sinus tumor.

recA gene dependence of replication of the Escherichia coli chromosome initiated by plasmid pUC13 integrated at predetermined sites

Plasmid pUC13 was used to clone DNA fragments of known sites from the chromosome of Escherichia coli. Each chimeric plasmid was introduced individually into the same dnaA46 mutant strain LC381 and suppressive integration (Sin) strains were selected. By means of cotransduction the null mutation recA56 was then introduced into each Sin strain and growth of each recA56 derivative at 42 degrees C was scored. Strains that failed to grow at 42 degrees C depended upon the recA gene for replication. Three factors were shown to limit the viability of LC381 harboring different chimeric plasmids and affect the degree of recA gene dependence of chromosome replication in the Sin strains at 42 degrees C. It is suggested that these three constraints are the consequence of the organization of the E. coli chromosome, particularly the unique ability of terC to retard the progression of replication forks. Two classes of hypotheses concerning the function of the recA gene are considered.

Re-endothelialization of isolated segments of the canine carotid artery with reference to the possible role of the adventitial vasa vasorum

This study was designed to determine if the adventitial vasa vasorum contribute to re-endothelialization of the canine carotid artery after removal of the endothelial flow surface. Casting studies demonstrated that vasa vasorum are present only in the adventitia of the canine carotid artery. Ninety autograft segments of the carotid artery from which the endothelium had been removed were implanted in both carotid arteries of 45 dogs. Glutaraldehyde-processed canine carotid allografts were positioned at each end to prevent pannus ingrowth and a Gore-Tex wrap to prevent periarterial tissue growth was placed into the outer wall. Three methods were used, with observations at 4 and 8 weeks. In method 1 the test segment was treated with superficial endarterectomy. In method 2 a balloon catheter was used to remove the endothelium. In method 3 balloon catheter denudation of the flow surface was also employed and, in addition, the adventitia was removed surgically as completely as possible, although a few vasa vasorum were shown to remain in some grafts. In method 1 all the patent endarterectomized arteries were partially re-endothelialized at both the 4- and 8-week intervals. In method 2, 72% of the balloon-denuded patent arteries with intact adventitial vasa vasorum were partially re-endothelialized at 4 weeks and 84% at 8 weeks. However, in method 3 the flow surfaces had no endothelium at 4 weeks and 83% still had none at 8 weeks. These findings suggest that, in the absence of pannus ingrowth, re-endothelialization of the canine carotid artery depends on not only the presence but also the number of adventitial vasa vasorum.

Implant site: a determinant of completeness of arterial prosthesis healing in the dog and possibly in humans

This paper compares the healing of supported knitted Dacron prostheses implanted in the descending thoracic aorta and in the subcutaneous carotid-femoral positions in each of 10 dogs. The descending thoracic aorta prostheses were 6 cm long and the carotid-femoral prostheses averaged 76 cm in length. The healing of four porous clinical axillofemoral grafts is compared to that of the experimental carotid-femoral grafts. There was little similarity between the healing observed in the descending thoracic aortic and subcutaneous positions; the descending thoracic aorta grafts healed rapidly and completely by eight weeks, with thrombus-free flow surfaces covered with confluent endothelial cells. However, the inner wall of the carotid-femoral grafts remained largely unhealed at one year, with endothelialization largely confined to a limited pannus ingrowth across the anastomoses. This indicates that the implant site in the dog is a primary determinant of the rapidity and completeness of healing. The clinical axillofemoral grafts explanted after 20 months to six and one-half years exhibited healing characteristics that were similar to those seen in the carotid-femoral position in the dog. These findings suggest that valid comparisons of interspecies healing require data obtained from similar implant locations. They present a challenge to the previously held concepts of major interspecies differences in speed and extent of tissue ingrowth based on data obtained from noncomparable implant sites.

Allogeneic bone marrow transplantation for the treatment of leukemia

Eighteen patients with leukemia have received HLA-identical allogeneic bone marrow transplantation (BMT) at our hospital since 1981. Fifteen of these patients have been living without relapse. for prophylaxis of GVHD, MTX was used in 8 patients, and cyclosporine (CSP) together with MTX in 6 patients, 3 received multiple agents at much smaller dosage, including monoclonal antibody. All patients received intravenous placental gamma-globulin, and 16 received garlic extract. Three patients died. One, who neither received MTX, nor CSP died of hyperacute GVHD, one who did not receive garlic extract died of GMV pneumonia, and the third one died of tuberculosis 18 months after BMT.

The evolution of a clinically relevant experimental model for the realistic evaluation of long-length (80-cm) arterial prostheses

A new carotid-femoral experimental model has been developed which has significant clinical relevance to human limb salvage bypass grafting in the areas of graft length, hemodynamics and tissue environment. More significantly, the graft healing pattern observed with this model is similar to what is seen in humans. Therefore, this experimental model provides a challenging and critical site for dynamic healing studies and comparisons of different types of vascular prostheses.

[Effect of myocardial alpha 1-adrenoceptor stimulation on the guinea-pig ventricular papillary muscle]

The alpha-adrenoceptor agonist phenylephrine (5.0 x 10(-6) mol/L) was used to stimulate myocardial alpha-adrenoceptors of the guinea-pig ventricular papillary muscle, and changes of transmembrane action potential and contractile force of the muscle were observed. The alpha 1-adrenoceptor blocker prazosin (5.0 x 10(-7) mol/L) and the alpha 2-adrenoceptor blocker yohimbine (5.0 x 10(-7) mol/L) were used to determine which subtype of alpha-adrenoceptor is responsible for the effects. The beta-adrenoceptor blocker propranolol (1.0 x 10(-6) mol/L) was used throughout the experiment. The results show that the myocardial alpha 1-adrenoceptor stimulation (1) increases the contractile force of the guinea-pig ventricular papillary muscle, (2) prolongs the time to peak contractile force while the duration of relaxation is not altered, (3) prolongs the fast response action potential duration, and (4) increases the maximal rate of depolarization during the phase 0 of the slow response action potential. It is suggested that the electrophysiological and positive inotropic effects of myocardial alpha 1-adrenoceptor stimulation might be due to the activation of the slow inward current and an increase in Ca2+ influx.