Tolerance to experimental cardiac allografts produced by neonatal intrathymic injection of donor cells

Intrathymic inoculation of allogeneic cells after systemic administration of antilymphocyte serum in adult experimental animals has produced donor-specific tolerance to cardiac allografts. We investigated whether thymic injection of allogeneic cells without antilymphocyte serum in neonatal Lewis rats (day 1 of life) with immature immune systems also produced tolerance to cardiac grafts. Intrathymic or intraperitoneal injection of 5 x 10(7) Lewis (control) or Lewis-Brown Norway (allogeneic) spleen cells in Lewis neonates was followed by heterotopic cardiac transplantation using Lewis, Lewis-Brown Norway, or Wistar Furth (third-party allograft) hearts at 6 to 8 weeks of age. Graft survival was prolonged with both intraperitoneal and intrathymic allogeneic cells. Recipients of cells by the intrathymic route had longer graft survival, and 2 of 5 animals achieved permanent graft acceptance (longer than 100 days). As expected, Lewis isografts survived indefinitely, whereas third-party Wistar Furth allografts were rejected in the usual time frame. Intrathymic introduction of allogeneic cells in a neonatal recipient with an immature immune system can produce donor-specific tolerance to a subsequent graft without the need for a systemic immunosuppression regimen, even transiently.

Chromogranin A and B in neuronal elements in Hirschsprung's disease: an immunocytochemical and radioimmunoassay study

Chromogranin A and B (CAB) occur in several peptide hormone-producing cells and in neurons of the brain. The aim of the present study was to investigate the possible neuronal localization of these chromogranins in the ganglionic and aganglionic bowel in Hirschsprung's disease by immunocytochemistry and radioimmunoassay, using antibodies recognizing either chromogranin A or both chromogranin A and B. Further, the coexistence of chromogranins and other neuronal constituents was studied. CAB were found in nerve fibers and occasionally in nerve cell bodies of submucous and myenteric ganglia in the ganglionic bowel, indicating that at least a population of chromogranin-immunoreactive nerve fibers is intrinsic in origin. CAB-immunoreactive fibers were numerous in the muscle layers of the aganglionic segment. These fibers contained tyrosine hydroxylase (TH), which indicates that they are adrenergic, in both ganglionic and aganglionic bowel. In the muscle layers of aganglionic (but not ganglionic) bowel, chromogranin A coexisted with galanin, neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP). The concentration of CAB in smooth muscle specimens was higher in the aganglionic bowel than in the ganglionic bowel. Thus, chromogranins are present in the human enteric gut hyperinnervating the aganglionic bowel of Hirschsprung's disease.

Effects of specific fatty acid acylation of phospholipase A2 on its interfacial binding and catalysis

Monomeric phospholipase A2 (PLA2) from the venom of Agkistrodon piscivorus piscivorus (App-D49) was treated with 3-acyloxy-4-nitrobenzoic acids to acylate the epsilon-amino groups of two lysines (Lys-7 and Lys-10) in the amino terminal region. Resulting 7,10-diacylated-App-D49s, with acyl groups ranging from lauroyl to palmitoyl, spontaneously aggregated in solution. By contrast, 7,10-dioctanoyl-App-D49 existed as a monomer under the same condition. Kinetic and interfacial binding properties of diacylated enzymes indicated that they catalyzed the hydrolysis at the interface as a monomer. When compared to nonacylated App-D49, diacylated enzymes showed slightly increased activity or decreased activity toward monodispersed 1,2-dibutyryl-sn-glycero-3-phosphocholine, Triton X-100/1,2-dilauroyl-sn-glycero-3-phosphocholine mixed micelles, and small unilamellar vesicles (SUV) of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Toward densely-packed liquid-crystalline phospholipid bilayers, such as large unilamellar vesicles (LUV) of POPC, however, diacylated enzymes exhibited a large increase in activity, which reacted up to 250-fold for 7,10-dilauroyl-App-D49 ((kcat/Km)app = (1.0 +/- 0.02) x 10(6) M-1 s-1). Measurements of the penetration of individual diacylated enzymes into 2-oleoyl-3-palmitoyl-sn-glycero-1-phosphocholine (i.e., D-POPC) monolayers indicated that the acyl groups enhanced the interfacial binding of protein by interacting with hydrocarbon moieties of phospholipids and that these hydrophobic interactions remained effective even when the phospholipid packing density was high. Furthermore, fluorometric measurements of the binding of diacylated enzymes to polymerized vesicles of 1,2-bis[12-(lipoyloxy)dodecanoyl]-sn-glycero-3-phosphocholine showed that the hydrophobic interactions increased the enzymatic activity toward LUV by accelerating the migration of enzyme molecules to vesicle surfaces. The analysis of the kinetic course of POPC LUV hydrolysis showed that diacylated enzymes as a catalyst were superior to nonacylated App-D49 in that they were not only more catalytically efficient but also able to catalyze more turnovers without being trapped in product-containing vesicles. In summary, the acylation of App-D49 by 3-acyloxy-4-nitrobenzoic acids provides a simple and convenient way of converting the enzyme into a highly active form toward densely-packed liquid-crystalline phospholipid bilayers, which might have potential industrial and biomedical applications.

Slowly activating voltage-dependent K+ conductance is apical pathway for K+ secretion in vestibular dark cells

Dark cell epithelium secretes K+ into the lumen of the vestibular labyrinth by a previously unidentified apical transport mechanism. Previous single-channel patch-clamp studies demonstrated nonselective cation channels and maxi-K+ channels in the apical membrane, but in too low a density to account for transepithelial K+ transport. In this report, we demonstrated with the cell-attached macro-patch-clamp technique an outward apical membrane current at 0-mV pipette voltage, which was stimulated by elevating bath K+ concentration from 3.6 to 25 mM and inhibited by 10 microM bumetanide, similar to their known effects on transepithelial short-circuit current and K+ secretion. Furthermore, the patch current was activated over several seconds by a sustained depolarization and deactivated over several hundred milliseconds by a hyperpolarization. Current-voltage relationships from tail currents were obtained with either NaCl or KCl in the pipette. Depolarization from -40 to +40 mV led to an increased conductance by a factor of 7.3 +/- 1.7 (n = 7) and 19.2 +/- 7.6 (n = 6) for NaCl and KCl, respectively, and to a reversal voltage near the presumed equilibrium potential for K+. The results demonstrate that dark cell K+ secretion occurs via K(+)-selective channels with characteristics similar to those associated with the IsK protein.

Conformation of the central, three-helix junction of the 5 S ribosomal RNA of Sulfolobus acidocaldarius

The current investigation has focused on the structure of the central, three-helix junction of the 5 S ribosomal RNA from Sulfolobus acidocaldarius, a thermoacidophilic archaebacterium. The 5 S molecule from S. acidocaldarius represents a paradigm for the study of the 5 S junction (and branched RNA structures in general) due to its unusually high degree of predicted secondary structure and stability. In order to study the junction in isolation, a set of three RNA heteroduplex molecules was assembled in which pairs of helices bounding the junction were extended by 70 base-pairs per helix. Since the extended helices comprise more than 95% of the heteroduplex structure, the relative solution conformations of the heteroduplex molecules, in effect, "report" the interhelix (branch) angles bounded by the extended pairs of helices. Examination of these heteroduplex molecules, using a combination of gel electrophoresis and transient electric birefringence measurements, has revealed a tertiary structure for the central branch in which helices I and V are essentially collinear, and in which helix II is relatively free to reorient with respect to the I-V axis.

Enhanced cytochrome P450 (Cyp1b1) expression, aryl hydrocarbon hydroxylase activity, cytotoxicity, and transformation of C3H 10T1/2 cells by dimethylbenz(a)anthracene in conditioned medium

The basal and benz(a)anthracene-induced aryl hydrocarbon hydroxylase activities of C3H 10T1/2 mouse embryo fibroblasts have been shown to vary with population growth. We report here that, in the case of dimethylbenz(a)anthracene, cytotoxicity and transformation (neoplastic/morphological transformation and focus formation) increased as a consequence of population growth and, at high cell densities, DNA adduct formation was elevated. Among the factors that may contribute to these changes, we have found that conditioning of the medium with population growth plays a significant role. Cells treated with medium conditioned by several days of cell growth supported increases in the dimethylbenz(a)anthracene induction of mRNA expression of a new mouse cytochrome P450 gene designated Cyp1b1, aryl hydrocarbon hydroxylase activity, cytotoxicity, and the frequency of neoplastic transformation. These results suggest a cause and effect relationship between the enhanced expression of Cyp1b1 due to medium conditioning and the enhanced expression of the cellular endpoints cytotoxicity and transformation.

Three-dimensional echocardiography: in vitro and in vivo validation of left ventricular mass and comparison with conventional echocardiographic methods

OBJECTIVES

This study aimed to validate a method for mass computation in vitro and in vivo and to compare it with conventional methods.

BACKGROUND

Conventional echocardiographic methods of determining left ventricular mass are limited by assumptions of ventricular geometry and image plane positioning. To improve accuracy, we developed a three-dimensional echocardiographic method that uses nonparallel, nonintersecting short-axis planes and a polyhedral surface reconstruction algorithm for mass computation.

METHODS

Eleven fixed hearts were imaged by three-dimensional echocardiography, and mass was determined in vitro by multiplying the myocardial volume by the density of each heart and comparing it with the true mass. Mass at diastole and systole by three-dimensional echocardiography and magnetic resonance imaging (MRI) was compared in vivo in 15 normal subjects. Ten subjects also underwent imaging by one- and two-dimensional echocardiography, and mass was determined by Penn convention, area-length and truncated ellipsoid algorithms.

RESULTS

In vitro results were r = 0.995, SEE 2.91 g, accuracy 3.47%. In vivo interobserver variability for systole and diastole was 16.7% to 27%, 14% to 18.1% and 6.3% to 12.8%, respectively, for one-, two- and three-dimensional echocardiography and was 7.5% for MRI at end-diastole. The latter two agreed closely with regard to diastolic mass (r = 0.895, SEE 11.1 g) and systolic mass (r = 0.926, SEE 9.2 g). These results were significantly better than correlations between MRI and the Penn convention (r = 0.725, SEE 25.6 g for diastole; r = 0.788, SEE 28.7 g for systole), area-length (r = 0.694, SEE 24.2 g for diastole; r = 0.717, SEE 28.2 g for systole) and truncated ellipsoid algorithms (r = 0.687, SEE 21.8 g for diastole; r = 0.710, SEE 24.5 g for systole).

CONCLUSIONS

Image plane positioning guidance and elimination of geometric assumptions by three-dimensional echocardiography achieve high accuracy for left ventricular mass determination in vitro. It is associated with higher correlations and lower standard errors than conventional methods in vivo.

cDNA cloning, sequence analysis, and induction by aryl hydrocarbons of a murine cytochrome P450 gene, Cyp1b1

C3H mouse embryo fibroblast cells, designated 10T1/2, can be transformed by physical and chemical agents including polycyclic aromatic hydrocarbons. In a previous report (Shen et al., Proc. Natl. Acad. Sci. USA 90, 11483-11487, 1993), we identified a cytochrome P450 gene induced by polycyclic aromatic hydrocarbons (PAHs) that is different from 1A1 or 1A2, and which we tentatively named P450CMEF. Here, we report the entire cDNA sequence of P450CMEF (5,128 bp) and the amino acid sequence deduced from it (543 residues). A comparison of the latter sequence with known cytochrome P450s indicates that P450CMEF is in a new subfamily of family 1 of the P450 superfamily. Accordingly, the Committee on Standardized Cytochrome P450 Nomenclature designated the gene Cyp1b1. Exposure to various aryl hydrocarbons (2.5 hr) induced Cyp1b1 mRNA in 10T1/2 cells to different degrees: 2,3,7,8-tetrachlorodibenzo-p-dioxin, 7,12-dimethylbenz[a]anthracene, benz[a]anthracene, benzo[a]pyrene, and beta-naphthoflavone were strong inducers; alpha-naphthoflavone and 3-methylcholanthrene, were moderate inducers; and benzo[e]pyrene was a weak inducer.

Histocompatibility differences and cardiac transplant tolerance produced by intrathymic pretreatment

Control of cardiac transplant rejection without toxic immunosuppressive drugs remains an unreached goal. Our laboratory and others have shown that intrathymic inoculation of donor-specific allogeneic spleen cells can produce tolerance to a subsequent cardiac allograft. The present experiments were designed to investigate whether the degree of donor-recipient histoincompatibility influenced the efficacy of this technique. Four congeneic strains of rats with different degrees of histoincompatibility were studied. Heterotopic cardiac transplantation was done with the following congeneic strain combinations: DA donor into PVG recipient (full major histocompatibility complex and nonmajor histocompatibility complex incompatibility); PVG.RT1a donor into PVG recipient (full major histocompatibility complex incompatibility); PVG.RT1a donor into PVG.R1 recipient (partial major histocompatibility complex incompatibility). Prospective graft recipients underwent intraperitoneal injection of 1 ml antilymphocyte serum and intrathymic injection of 5 x 10(7) prospective donor spleen cells. Three weeks later, heterotopic cardiac transplantation was done with a heart from a donor of the same strain as that used to obtain splenocytes for intrathymic injection. Prolongation of graft survival was observed in pretreated recipients in all strain combinations but was greatest in recipients that differed from donors at fewer histocompatibility loci. Complete graft tolerance was not seen in strain combinations that included nonmajor histocompatibility complex incompatibilities. DA heart survival in PVG recipients was 50.6 days (p < 0.04 versus controls); PVG.RT1a graft survival in PVG hosts was 165.8 days (p < 0.02 versus control) and in PVG.R1 recipients 163.8 days (p < 0.02 versus controls) with four of five grafts in each group surviving indefinitely (more than 200 days).

Immunocytochemical evidence for chromogranin A and B in neuronal elements in human gut

Chromogranins are a family of acidic proteins known to occur in the secretory granules of endocrine cells and neurons in mammals. The aim of the present study was to investigate the possible neuronal localisation of chromogranins in human intestine and their relationship with other neuronal constituents using one antibody recognizing both chromogranin A and B (CAB) and others recognizing only chromogranin A. Immunoreactive CAB was found to occur in mucosal endocrine cells and in neuronal elements of all layers throughout human gut. A few to large number of CAB-immunoreactive nerve fibers were seen in smooth muscles as well as in submucous and myenteric ganglia and they were regularly found around blood vessels. Occasional CAB immunoreactive nerve cell bodies could be demonstrated in both submucous and myenteric ganglia indicating a local origin of some of the immunoreactive fibers. Most of these neurons seemed to lack acetylcholine esterase, and could be classified as non-cholinergic. CAB coexisted with the catecholamine-synthesizing enzyme tyrosine hydroxylase indicating the presence of chromogranins in noradrenergic nerve fibers. The presence of CAB-immunoreactive nerve cell bodies indicates that some CAB-containing fibers are intrinsic in origin. The distribution of chromogranin A and B immunoreactive nerve fibers in all layers of the gut wall suggests multiple targets for neuronal CAB, and/or their processing products.

Correlations among tyrosine phosphorylation of Shc, p72syk, PLC-gamma 1, and [Ca2+]i flux in Fc gamma RIIA signaling

Tyrosine phosphorylation plays a critical role in Fc gamma RIIA signaling. In a mouse macrophage cell line transfected with human Fc gamma RIIA, cross-linking Fc gamma RIIA led to the transient generation of inositol 1, 4, 5-trisphosphate (IP3), [Ca2+]i flux, and rapid tyrosine phosphorylation of cellular substrates, including Shc, PLC-gamma 1, and a tyrosine kinase p72syk. In addition, tyrosine phosphorylated Fc gamma RIIA was co-precipitated with activated PLC-gamma 1. In contrast, no tyrosine phosphorylation of Shc or PLC-gamma 1 was detected in cells transfected with mutant receptors that failed to trigger [Ca2+]i flux. PMA inhibits both tyrosine phosphorylation of Shc and IP3 production leading to [Ca2+]i flux. However, PMA does not affect tyrosine phosphorylation of PLC-gamma 1 and p72syk. These results suggest that tyrosine phosphorylation of Shc and PLC-gamma 1 is important for the initiation of [Ca2+]i flux, and that activation of protein kinase C may modulate the activity of PLC-gamma 1 through serine/threonine phosphorylation.

Correlations among tyrosine phosphorylation of Shc, p72syk, PLC-gamma 1, and [Ca2+]i flux in Fc gamma RIIA signaling

Tyrosine phosphorylation plays a critical role in Fc gamma RIIA signaling. In a mouse macrophage cell line transfected with human Fc gamma RIIA, cross-linking Fc gamma RIIA led to the transient generation of inositol 1, 4, 5-trisphosphate (IP3), [Ca2+]i flux, and rapid tyrosine phosphorylation of cellular substrates, including Shc, PLC-gamma 1, and a tyrosine kinase p72syk. In addition, tyrosine phosphorylated Fc gamma RIIA was co-precipitated with activated PLC-gamma 1. In contrast, no tyrosine phosphorylation of Shc or PLC-gamma 1 was detected in cells transfected with mutant receptors that failed to trigger [Ca2+]i flux. PMA inhibits both tyrosine phosphorylation of Shc and IP3 production leading to [Ca2+]i flux. However, PMA does not affect tyrosine phosphorylation of PLC-gamma 1 and p72syk. These results suggest that tyrosine phosphorylation of Shc and PLC-gamma 1 is important for the initiation of [Ca2+]i flux, and that activation of protein kinase C may modulate the activity of PLC-gamma 1 through serine/threonine phosphorylation.

Exogenous myristic acid can be partially degraded prior to activation to form acyl-acyl carrier protein intermediates and lipid A in Vibrio harveyi

To study the involvement of acyl carrier protein (ACP) in the metabolism of exogenous fatty acids in Vibrio harveyi, cultures were incubated in minimal medium with [9,10-3H]myristic acid, and labeled proteins were analyzed by gel electrophoresis. Labeled acyl-ACP was positively identified by immunoprecipitation with anti-V. harveyi ACP serum and comigration with acyl-ACP standards and [3H]beta-alanine-labeled bands on both sodium dodecyl sulfate- and urea-polyacrylamide gels. Surprisingly, most of the acyl-ACP label corresponded to fatty acid chain lengths of less than 14 carbons: C14, C12, C10, and C8 represented 33, 40, 14, and 8% of total [3H]14:0-derived acyl-ACPs, respectively, in a dark mutant (M17) of V. harveyi which lacks myristoyl-ACP esterase activity; however, labeled 14:0-ACP was absent in the wild-type strain. 14:0- and 12:0-ACP were also the predominant species labeled in complex medium. In contrast, short-chain acyl-ACPs (< or = C6) were the major labeled derivatives when V. harveyi was incubated with [3H]acetate, indicating that acyl-ACP labeling with [3H]14:0 in vivo is not due to the total degradation of [3H]14:0 to [3H]acetyl coenzyme A followed by resynthesis. Cerulenin increased the mass of medium- to long-chain acyl-ACPs (> or = C8) labeled with [3H]beta-alanine fivefold, while total incorporation of [3H]14:0 was not affected, although a shift to shorter chain lengths was noted. Additional bands which comigrated with acyl-ACP on sodium dodecyl sulfate gels were identified as lipopolysaccharide by acid hydrolysis and thin-layer chromatography. The levels of incorporation of [3H] 14:0 into acyl-ACP and lipopolysaccharide were 2 and 15%, respectively, of that into phospholipid by 10 min. Our results indicate that in contrast to the situation in Escherichia coli, exogenous fatty acids can be activated to acyl-ACP intermediates after partial degradation in V. harveyi and can effectively label products (i.e., lipid A) that require ACP as an acyl donor.

Reconstruction of refractory defect of scalp and skull using microsurgical free flap transfer

Ten patients--six with acute burns, two with old accident or surgical trauma, and two with cranial carcinoma--experienced extensive full-thickness necrosis of the scalp and necrosis or defect of underlying skull bone. Microsurgical free flaps were used for the repair. Four latissimus dorsi, two rectus abdominis, one greater omentum, one prefabricated omentum-cutaneous flap, and two vascularized outer-table of the cranial bone flaps were used with complete survival. The heat-devitalized cranial bone covered by living tissue flaps healed well and substantial "regeneration" of previously necrosed bone was shown by roentgenogram, bone scan, and histopathological examination in the postoperative follow-up. Choosing an artery with high perfusion, bypassing from the carotid artery to support a massive free flap, is recommended.

Development of tolerance to experimental cardiac allografts in utero

"Actively acquired tolerance" to foreign cells was described in 1953 by Medawar and colleagues and formed the basis for subsequent efforts in organ transplantation. We have applied these historic principles of intrauterine immune manipulation in a vascularized cardiac allograft model. Allogeneic Lewis-Brown Norway (LBN) splenocytes (0 to 5 x 10(7) cells) were injected intraperitoneally into each fetus of a pregnant Lewis rat at day 14 to 16 of gestation, when T cells are "educated" to distinguish self from foreign. This manipulation causes fetal attrition inversely proportional to the number of cells injected. Heterotopic transplantation using an LBN heart was carried out in each surviving fetus at 6 to 8 weeks of age. Untreated Lewis rats rejected LBN hearts within 7.6 days. Rats receiving LBN splenocytes in utero demonstrated prolongation of graft survival proportional to the number of cells given. Surviving animals exposed to 5 x 10(7) allogeneic cells in utero (n = 4) had graft survivals of 24 to more than 150 days (mean, 88.0 days), significantly longer than control animals (6 to 10 days; mean, 7.6 days; p < 0.02). Significant prolongation of cardiac allograft survival and in some cases complete tolerance can be achieved by intrauterine exposure to allogeneic cells at a critical period of immunologic development. Because many serious cardiac defects amenable to treatment by cardiac transplantation can be detected by ultrasound early in gestation, treatment based on this strategy may become useful in pediatric heart transplantation.

Fc receptor-mediated signal transduction

Receptors for the Fc domain of IgG (Fc gamma Rs) on leukocytes mediate a pleiotropic response following cross-linking by immune complexes. Signaling events following cross-linking of B and T cell antigen receptors, Fc epsilon RI, and Fc gamma Rs share common elements. In each, signaling is initiated by receptor cross-linking by antigen or immune complexes and results in the activation of src family kinases and ZAP-70-related tyrosine kinases, which associate with members of the receptor complex. Subsequent events include phosphorylation on tyrosine of multiple cellular substrates including phospholipase C gamma 1 and PI3-kinase. The [Ca2+]i flux is an event secondary to phospholipase C gamma 1 activation. Protein tyrosine kinase inhibitors block both early events such as [Ca2+]i flux and the later effects of cytokine release and cellular proliferation.

Identification of a cytochrome P450 gene by reverse transcription--PCR using degenerate primers containing inosine

A cytochrome P450-like gene, tentatively named P450CMEF, was amplified by a mixed oligonucleotide-primed amplification of cDNA from C3H mouse embryo fibroblast cells, designated 10T1/2, that had been treated with 7,12-dimethylbenz[a]anthracene (DMBA) or benz[a]anthracene (BA). A set of inosine-containing degenerate primers that were targeted to two conserved regions of known cytochrome P450 cDNAs were used. One primer was coded for the well-described and conserved heme-binding region of P450 enzymes, and the second was designed based upon other considerations of homology among P450 molecules. One of the four PCR-amplified cDNA products hybridized to two major RNA bands, 4.2 and 5.3 kb, that were induced by DMBA or BA. The amino acid sequence of the fragment deduced from the base-sequence data indicate that the amplified cDNA has a 50-55% identity with the cytochrome P450 subfamily 1A. The induction of P450CMEF mRNA preceded the induction of aryl hydrocarbon hydroxylase activity after DMBA or BA treatment, suggesting that the product of P450CMEF is involved in the metabolism of these polycyclic aromatic hydrocarbons in 10T1/2 cells. From the partial sequence of the cDNA identified by this procedure, we propose that P450CMEF is a member of the P450 superfamily, possibly in a subfamily of family 1, that is induced in 10T1/2 cells by DMBA and BA. This method should be useful in identifying additional P450 genes and genes in other gene families.

Diagnostic value of left ventricular dyssynergy patterns in ischemic and non-ischemic cardiomyopathy

BACKGROUND

The distinction between ischemic and non-ischemic cardiomyopathy has important clinical implications. The objective of the present study was to investigate whether left ventricular dyssynergy patterns, detected by quantitative analysis of ultrasound images, differed in these two pathological processes.

METHODS

Fifty-six consecutive patients with congestive heart failure (New York Heart Association functional class II-IV) secondary to depressed left ventricular systolic function (ejection fraction < or = 35% during diagnostic cardiac catheterization) were studied. Twenty patients were eliminated from further analysis because they met one or more exclusion criteria. The remaining 36 were divided into two groups based on the presence (ischemic cardiomyopathy) or absence (non-ischemic cardiomyopathy) of a > or = 50% narrowing of the luminal diameter in one or more coronary arteries. In all patients, a standard two-dimensional echocardiographic study was obtained. Apical four- and two-chamber views with optimal endocardial and epicardial resolution were selected for analysis, and the left ventricular contour was divided into six segments of interest. Optimal endocardial and epicardial resolution were defined according to an original internal quality score system. For each of the six segments of interest, regional ejection fraction and regional segmental thickening were estimated. Data analysis was then performed on the average values of regional ejection fraction and regional segmental thickening obtained across the entire left ventricular contour. In each patient, regional ejection fraction range and regional segmental thickening range were calculated by subtracting the minimum from the maximum value of regional ejection fraction and regional segmental thickening obtained across a left ventricular contour.

RESULTS

Regional ejection fraction and regional segmental thickening did not differ significantly between the two groups. However, regional ejection fraction range and regional segmental thickening range were significantly greater in patients with ischemic cardiomyopathy than in patients with non-ischemic cardiomyopathy [28.32 +/- 11.17 versus 14.74 +/- 7.73% (P < 0.001) and 47.80 +/- 16.00 versus 24.64 +/- 9.39% (P < 0.001), respectively]. Overlap of findings was observed in 20% of the values for regional ejection fraction range but in only 14% of those for regional segmental thickening range.

CONCLUSIONS

Patients with ischemic cardiomyopathy demonstrate a non-uniform dyssynergy that can be differentiated from a more uniform hypokinesis observed in those with non-ischemic cardiomyopathy. Computerized ultrasonic image analysis can distinguish characteristic dyssynergic patterns in patients with cardiomyopathy. Measurements of segmental wall thickening provide a more accurate assessment of regional function.

Peptide-containing neurons remain unaffected after intestinal autotransplantation: an experimental study in the piglet

The gut is richly supplied with peptide-containing nervous elements. In the present immunocytochemical study the origin, occurrence and topographical distribution of nerves containing vasoactive intestinal polypeptide (VIP), enkephalin, substance P (SP), somatostatin, neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), gastrin-releasing peptide (GRP) and galanin were investigated in the porcine small intestine. In order to study the origin (extrinsic or intrinsic) of the nerve fibers, specimens from autotransplanted and extrinsically denervated jejunum were examined. Furthermore, possible changes in the distribution of intrinsic neurons after extrinsic denervation were studied. In the control jejunum each nerve fiber population had its own characteristic topographic distribution. There was no overt difference in distribution pattern of peptide-containing nerve fibers and cell bodies between the transplanted and the control segment except that NPY-, SP- and CGRP-containing nerve fibers disappeared around blood vessels. Thus VIP-, somatostatin-, GRP-, enkephalin- and galanin-containing nerve fibers were visibly unchanged in the transplanted segment. The results support the view that the peptide-containing nerve fibers are mainly intrinsic in origin except the NPY-, SP- or CGRP-containing perivascular nerve fibers which are extrinsic to the gut wall. In addition, the results of the present study suggest that transplantation and extrinsic denervation have no major effect on the distribution pattern of the intrinsic neuronal systems.

Experiments in cardiac xenotransplantation. Response to intrathymic xenogeneic cells and intravenous cobra venom factor

Permanent tolerance to an experimental cardiac allograft can be achieved by pretransplantation intrathymic inoculation of donor-specific lymphoid cells. We studied the effects of intrathymic inoculation of xenogeneic cells and intravenous cobra venom factor in a rodent model of cardiac xenotransplantation. Lewis rats underwent intraabdominal heterotopic heart transplantation with Syrian hamster donors. In untreated animals, mean graft survival time was 3 days. Five rats had 1 ml of antilymphocyte serum administered intraperitoneally. One day later, 2.5 x 10(7) hamster spleen cells were inoculated into the thymus under direct vision. Twenty-one days after antilymphocyte serum was given, heterotopic heart transplantation with a hamster donor was carried out. In all cases, rejection was accelerated and occurred between 20 minutes and 1 day after transplantation. Mean graft survival time was 5.2 hours (p < 0.0001 versus control). Six animals treated with antilymphocyte serum and intrathymic xenogeneic cells had 0.5 ml of cobra venom factor, a complement antagonist, administered intravenously 3 hours before transplantation and every other day thereafter. Mean graft survival was 3 days, which was not different from the response of naive animals. Animals treated with antilymphocyte serum only had no prolongation of graft survival (mean survival time 3 days, p = not significant). Animals treated with cobra venom factor alone (n = 5) before transplantation and on alternate days subsequently had mild graft prolongation with a mean survival time of 4 days (p = 0.0133). In contrast to experimental allograft models, intrathymic inoculation of xenogeneic cells produces hyperacute rejection in these naturally concordant species. The administration of cobra venom factor abrogates the hyperacute response, but the combination of cobra venom factor and intrathymic inoculation does not produce long-term graft survival.

Cycle sequencing using degenerate primers containing inosines

A modified protocol for cycle sequencing DNA amplified by polymerase chain reaction (PCR) is described. The method involves two sequential linear PCR amplifications using a small amount of double-stranded DNA as a template and a stringent annealing temperature: 1) alpha-35S-dATP labeling of specific primers initially in degenerate primer mixture and 2) dideoxy-ribonucleotide termination of the extended and alpha-35S-dATP-labeled specific primers. The method does not require end labeling and is useful in sequencing PCR-amplified DNA sequences from highly degenerate primers when the sequences of the regions flanking those to be primed are unknown.

Successful experimental heart transplantation without immunosuppressive drugs

Donor-specific unresponsiveness is an important goal of heart transplantation research. Work by other investigators has shown that intrathymic transplantation of pancreatic islet cells not only leads to factor permanent acceptance of the intrathymic graft but tolerance to subsequent extrathymic islet cell transplants. We applied this concept to a model of heart allotransplantation in the rat. Recipient Lewis rats were treated with 1 ml of antilymphocyte serum and 5 x 10(7) Lewis-Brown Norway spleen cells injected into the thymus under direct vision. Twenty-one days later, heterotopic heart transplantation was performed with Lewis-Brown Norway (allograft) and Wistar-Furth (third-party allograft) donors. Control Lewis recipients received no treatment, antilymphocyte serum alone, or antilymphocyte serum plus intrathymic syngeneic Lewis spleen cells. Another group of animals received intravenous Lewis-Brown Norway cells before transplantation with Lewis-Brown Norway heart donors. Untreated control animals had heart graft survival of 6 to 10 days (mean, 7.6 days) and 7 to 9 days (mean, 7.8 days) for Lewis-Brown Norway (n = 5) and Wistar-Furth (n = 5) donors, respectively. Antilymphocyte serum alone (n = 10) failed to prolong survival of Lewis-Brown Norway grafts (mean, 10.7 days; p = not significant). Antilymphocyte serum plus intrathymic Lewis cells (n = 5) did not prolong survival of a subsequent Lewis-Brown Norway graft (mean, 9.2 days; p = not significant). Survival of Wistar-Furth third-party allografts (n = 10) was not prolonged by intrathymic Lewis-Brown Norway cells (mean survival, 13.9 days; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

[Studies on percutaneous absorption of ruyi jinhuang san patcher with radioisotope tracer]

Berberine is one of the active ingredients in Ruyi Jinhuang San Patcher. With 3H-berberine as the tracer, a radio-labelled method was used for determining percutaneous rate and drug concentration of berberine in plasma in vivo and in vitro. A study on the percutaneous rate of different technological plasters and various animal skins was also carried out.

Prediction of single and multivessel coronary disease in patients after myocardial infarction according to quantitative ultrasound wall-motion analysis

Regional changes in left ventricular size and function characterize left ventricular remodeling and start very early after myocardial infarction. We studied the diagnostic value of left ventricular dyssynergic patterns in predicting the presence of single versus multivessel disease (MVD). Fifty-three consecutive patients with acute myocardial infarction were studied by ECG, two-dimensional echocardiography, and angiography during the same hospitalization. Thirty-eight normal subjects served as the control group. According to the angiographic findings, the patients were categorized as having: single-vessel disease (SVD, n = 17), two-vessel disease (n = 17), and three-vessel disease (n = 19). Two-dimensional echocardiography was performed and optimal frames from five cardiac cycles were digitized and quantitatively analyzed off-line with a microcomputer. Echocardiographic wall-motion analysis demonstrated a depressed regional segmental thickening in the infarcted area that was characteristic for each echocardiographic view. In the segments remote from the infarcted area, however, the three patient groups displayed differences in function that ranged from hyperkinetic in patients with SVD to hypokinetic in patients with MVD. Patients with SVD constantly displayed a wider range of segmental thickening when compared with patients with MVD and the control group (p < 0.05). In conclusion, patients with SVD after myocardial infarction display compensatory hyperkinesis of remote segments, which is attenuated in patients with MVD. The present study introduces new parameters of segmental myocardial function that might be helpful in predicting SVD and MVD in patients after myocardial infarction.

Purification and characterization of fatty acyl-acyl carrier protein synthetase from Vibrio harveyi

A Vibrio harveyi enzyme which catalyzes the ATP-dependent ligation of fatty acids to acyl carrier protein (ACP) has been purified 6,000-fold to apparent homogeneity by anion-exchange, gel filtration, and ACP-Sepharose affinity chromatography. Purified acyl-ACP synthetase migrated as a single 62-kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as an 80-kDa protein by gel filtration under reducing conditions. Activity of the purified enzyme was lost within hours in the absence of glycerol and low concentrations of Triton X-100. Acyl-ACP synthetase exhibited Kms for myristic acid, ACP, and ATP of 7 microM, 18 microM, and 0.3 mM, respectively. The enzyme was specific for adenine-containing nucleotides, and AMP was the product of the reaction. No covalent acyl-enzyme intermediate was observed. Enzyme activity was stimulated up to 50% by iodoacetamide but inhibited > 80% by N-ethylmaleimide: inhibition by the latter was prevented by ATP and ACP but not myristic acid. Dithiothreitol and sulfhydryl-directed reagents also influenced enzyme size, activity, and elution pattern on anion-exchange resins. The function of acyl-ACP synthetase has not been established, but it may be related to the capacity of V. harveyi to elongate exogenous fatty acids by an ACP-dependent mechanism.

Evaluation of 90:10 poly(D,L-lactide-co-glycolide) microspheres containing norethisterone: drug release and biodegradation

Poly(D,L-lactide-co-glycolide) (PLG, 90:10) microspheres containing 20% norethisterone (NET) were prepared by solvent evaporation method. Microspheres in the size ranges of 65 to 100 microns were sterilized by irradiation and used for further study. In vitro release showed fairly constant release of NET from the above microspheres over more than 90 days. However, in vivo drug release determined by residual NET analysis after i.m. injection in rats indicated a faster release rate. About 95% of NET was released in a period of 45 days. At the dose of 80 mg of microspheres, vaginal estrus cycles were inhibited for 45 days compared to 27 days for the same dose of NET crystals in rats. Biodegradation of the microspheres was tested by direct measurement of molecular weight losses and SEM observation of morphological changes of the microspheres, which showed continuous erosion in the internal matrix of microspheres with the decrease of molecular weight of PLG until total collapse of microspheres, and biodegradation was faster in rats than in human serum at 37 degrees C in vitro. Total degradation of 90:10 PLG microspheres was less than 7 months in rats and more than 9 months in vitro.

Automated detection and quantification of venous beading using Fourier analysis

Venous beading associated with diabetic retinopathy is currently assessed by means of subjective comparison to standard photographs from the modified Airlie House classification scheme. We describe a computerized grading scheme for venous beading. The algorithm, based on Fourier analysis of vessel width measurements, generates a venous beading index (VBI) for digitized colour fundus photographs. Colour photographs of local vessel segments about 1200 microns in length were evaluated by experienced graders. A comparison between the VBI and subjective grading showed good agreement. The mean VBI values across the four levels of clinical grading were significantly different (p = 0.000). Multiple comparison testing indicated that the VBI was able to significantly differentiate between all four categories except the "questionable" (grade 1) category (p < 0.05). We also found that progression of venous beading can be followed with the VBI. The results indicate that further development of automated grading of venous beading is warranted.

A novel neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP), in human intestine: evidence for reduced content in Hirschsprung's disease

A novel neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP), exhibits sequence homology with vasoactive intestinal polypeptide (VIP) and occurs in the mammalian brain, lung and gut. The distribution of PACAP in ganglionic and aganglionic portions of the large intestine of patients with Hirschsprung's disease was examined by immunohistochemistry and radioimmunoassay. PACAP-immunoreactive nerve fibers were distributed in all layers of the ganglionic and aganglionic segments of the intestine, although they were less numerous in the latter, and PACAP-immunoreactive nerve cell bodies were seen in the ganglionic portion of the intestine. The concentration of immunoreactive PACAP was lower in the aganglionic than in the ganglionic segment of the intestinal wall. PACAP and VIP were found to coexist in both ganglionic and aganglionic segments of the intestine. Apparently, PACAP participates in the regulation of gut motility. The scarcer PACAP innervation of the aganglionic segment may contribute to the defect in intestinal relaxation seen in patients with Hirschsprung's disease.

The cadC gene product of alkaliphilic Bacillus firmus OF4 partially restores Na+ resistance to an Escherichia coli strain lacking an Na+/H+ antiporter (NhaA)

A 5.6-kb fragment of alkaliphilic Bacillus firmus OF4 DNA was isolated by screening a library of total genomic DNA constructed in pGEM3Zf(+) for clones that reversed the Na+ sensitivity of Escherichia coli NM81, in which the gene encoding an Na+/H+ antiporter (NhaA) is deleted (E. Padan, N. Maisler, D. Taglicht, R. Karpel, and S. Schuldiner, J. Biol. Chem. 264:20297-20302, 1989). The plasmid, designated pJB22, contained two genes that apparently encode transposition functions and two genes that are apparent homologs of the cadA and cadC genes of cadmium resistance-conferring plasmid pI258 of Staphylococcus aureus. E. coli NM81 transformed with pJB22 had enhanced membrane Na+/H+ antiporter activity that was cold labile and that decreased very rapidly following isolation of everted vesicles. Subclones of pJB22 containing cadC as the only intact gene showed identical complementation patterns in vivo and in vitro. The cadC gene product of S. aureus has been proposed to act as an accessory protein for the Cd2+ efflux ATPase (CadA) (K. P. Yoon and S. Silver, J. Bacteriol. 173:7636-7642, 1991); perhaps the alkaliphile CadC also binds Na+ and enhances antiporter activity by delivering a substrate to an integral membrane antiporter. A 6.0-kb fragment overlapping the pJB22 insert was isolated to complete the sequence of the cadA homolog. A partial sequence of a region approximately 2 kb downstream of the cadA locus shares sequence similarity with plasmids from several gram-positive bacteria. These results suggest that the region of alkaliphile DNA containing the cadCA locus is present on a transposon that could reside on a heretofore-undetected endogenous plasmid.

Regulation of transcription of the cell division gene ftsA during sporulation of Bacillus subtilis

Three distinct 5' ends of ftsA mRNA were identified by S1 mapping and by primer extension analysis. These are thought to represent three transcription start sites. The transcripts from the downstream and upstream sites were detected throughout growth. The transcript from the middle site was not detected during exponential growth but was detected within 30 min of the start of sporulation, when it was the predominant transcript. Insertion of a cat cassette in the middle promoter, ftsAp2 (p2), did not affect vegetative growth but prevented postexponential symmetrical division and spore formation. Transcription from p2 was dependent on RNA polymerase containing sigma H, and promoter p2 resembled the consensus sigma H promoter. Transcription from p2 did not require expression of the spo0A, spo0B, spo0E, spo0F, or spo0K loci. Northern (RNA) blot analysis indicated that ftsA is cotranscribed with the adjacent ftsZ gene. Multiple promoters provide a mechanism by which essential vegetative genes can be subjected to sporulation control independent of control during vegetative growth. In the case of ftsA,Z, the promoters provide a mechanism to permit septum formation in conditions of nutrient depletion that might be expected to shut down the vegetative division machinery.

Preparation of fatty-acylated derivatives of acyl carrier protein using Vibrio harveyi acyl-ACP synthetase

A simple two-step purification of Vibrio harveyi fatty acyl-acyl carrier protein (acyl-ACP) synthetase, which is useful for the quantitative preparation and analysis of fatty-acylated derivatives of ACP, is described. Acyl-ACP synthetase can be partially purified from extracts of this bioluminescent bacterium by Cibacron blue chromatography and Sephacryl S-300 gel filtration and is stable for months at -20 degrees C in the presence of glycerol. Incubation of ACP from Escherichia coli with ATP and radiolabeled fatty acids (6 to 16 carbons in length) in the presence of the enzyme resulted in quantitative conversion to biologically active acylated derivatives. The enzyme reaction can be monitored by a filter disk assay to quantitate levels of ACP or by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography to detect ACP in cell extracts. With its broad fatty acid chain length specificity and optimal activity in mild nondenaturing buffers, the soluble V. harveyi acyl-ACP synthetase provides an attractive alternative to current chemical and enzymatic methods of acyl-ACP preparation and analysis.

The use of an external tibial fixator in the treatment of genu varum

This paper reports 72 cases of genu varum treated by a U-shaped osteotomy of the tibia and an oblique osteotomy of the fibula in combination with immobilization effected by a specially designed external tibial fixator. Owing to this modified approach, the patients were able to stand up and move about much earlier than usual. Our trial yielded 80.7% excellent, 16.6% good and 2.7% fair results. The treatment course was shortened to two thirds of the time required when using previously described techniques.

[Effects of caffeine on shuttle, operating behaviors, and brain metabolism in rats]

Effects of caffeine (30, 60, and 120 mg.kg-1, ip) on shuttling and operating behaviors in 80 rats were studied. Effects of caffeine (60, 120 mg.kg-1, ip) on contents of dinucleotides and pterins in 6 brain areas of 18 rats were investigated by HPLC with fluorescent detector. The results showed that the dose of caffeine that induced augment of shuttle behavior was lower than that induced operating behavior. Caffeine 120 mg.kg-1 inhibited both shuttling and operating behavior, decreased FAD content in caudate nucleus; caffeine 60 mg.kg-1 increased FAD in cerebellum and brain stem. Caffeine 60, 120 mg.kg-1 increased brain NADH contents, decreased pterin contents, and increased biopterin contents in some brain areas.

Effects of PGE2 and a thromboxane A2 analogue on uptake of IgG complexes and LDL by mesangial cells

Vasoactive agents such as angiotensin (ANG) and eicosanoids can influence macromolecular deposition in the glomerular mesangium. We studied whether prostaglandin E2 (PGE2) and U-46619 (a stable analogue of thromboxane A2) could directly affect the uptake of immunoglobulin G (IgG) complexes or low-density lipoprotein (LDL) by cultured rat mesangial cells (MC). Preincubation of MC with PGE2 (10(-6) M) resulted in decreased uptake (in counts.min-1.well-1) of IgG complexes (PGE2, 2,589 +/- 72; control, 3,840 +/- 114; P less than 0.001) and LDL particles (PGE2, 23,176 +/- 1,145; control, 37,216 +/- 4,520; P less than 0.05). MC preincubated with forskolin (10(-5) M) also showed decreased uptake of IgG complexes (forskolin, 2,896 +/- 196; control, 3,840 +/- 114; P less than 0.005) and LDL particles (forskolin, 23,176 +/- 1,145; control, 37,216 +/- 4,520; P less than 0.05). In contrast, preincubation with ANG II (5 x 10(-7) M) showed significantly higher uptake of IgG complexes (ANG II, 4,475 +/- 282; control, 3,787 +/- 277; P less than 0.05) and LDL (ANG II, 48,573 +/- 1,079; control, 44,697 +/- 770; P less than 0.05). Similarly, preincubation with U-46619 (10(-6) M) resulted in significantly higher uptake of IgG complexes (U-46619, 5,370 +/- 300; control, 3,659 +/- 307; P less than 0.02) and LDL (U-46619, 48,298 +/- 1,418; control, 44,697 +/- 770; P less than 0.05). After preincubation with cyclooxygenase inhibitor meclofenamate (10(-6) M), ANG II (5 x 10(-7) M) resulted in a significantly higher uptake of IgG complexes compared with uptake by MC treated with ANG II alone (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)