Activation of the inducible form of nitric oxide synthase in the brains of patients with multiple sclerosis

Nitric oxide (NO) has been implicated as a pathogenic mediator in a variety of central nervous system (CNS) disease states, including the animal model of multiple sclerosis (MS) and experimental allergic encephalomyelitis. We have examined post-mortem brain tissues collected from patients previously diagnosed with MS, as well as tissues collected from the brains of patients dying without neuropathies. Both Northern blot analysis and reverse transcriptase (RT)-driven in situ PCR (RT-in situ PCR) studies demonstrated that inducible NO synthase (iNOS) mRNA was present in the brain tissues from MS patients but was absent in equivalent tissues from normal controls. We have also performed experiments identifying the cell type responsible for iNOS expression by RT-in situ PCR in combination with immunohistochemistry. Concomitantly, we analyzed the tissues for the presence of the NO reaction product nitrotyrosine to demonstrate the presence of a protein nitrosylation adduct. We report here that iNOS mRNA was detectable in the brains of 100% of the CNS tissues from seven MS patients examined but in none of the three normal brains. RT-in situ PCR experiments also demonstrated the presence of iNOS mRNA in the cytoplasm of cells that also expressed the ligand recognized by the Ricinus communis agglutinin 1 (RCA-1), a monocyte/macrophage lineage marker. Additionally, specific labeling of cells was observed when brain tissues from MS patients were exposed to antisera reactive with nitrotyrosine residues but was significantly less plentiful in brain tissue from patients without CNS disease. These results demonstrate that iNOS, one of the enzymes responsible for the production of NO, is expressed at significant levels in the brains of patients with MS and may contribute to the pathology associated with the disease.

In vivo expression of inducible nitric oxide synthase in experimentally induced neurologic diseases

The purpose of this study was to investigate the induction of inducible nitric oxide synthase (iNOS) mRNA in the brain tissue of rats and mice under the following experimental conditions: in rats infected with borna disease virus and rabies virus, in mice infected with herpes simplex virus, and in rats after the induction of experimental allergic encephalitis. The results showed that iNOS mRNA, normally nondetectable in the brain, was present in animals after viral infection or after induction of experimental allergic encephalitis. The induction of iNOS mRNA coincided with the severity of clinical signs and in some cases with the presence of inflammatory cells in the brain. The results indicate that nitric oxide produced by cells induced by iNOS may be the toxic factor accounting for cell damage and this may open the door to approaches to the study of the pathogenesis of neurological diseases.

Osteoprotegerin inhibits prostate cancer-induced osteoclastogenesis and prevents prostate tumor growth in the bone

Prostate cancer (CaP) forms osteoblastic skeletal metastases with an underlying osteoclastic component. However, the importance of osteoclastogenesis in the development of CaP skeletal lesions is unknown. In the present study, we demonstrate that CaP cells directly induce osteoclastogenesis from osteoclast precursors in the absence of underlying stroma in vitro. CaP cells produced a soluble form of receptor activator of NF-kappaB ligand (RANKL), which accounted for the CaP-mediated osteoclastogenesis. To evaluate for the importance of osteoclastogenesis on CaP tumor development in vivo, CaP cells were injected both intratibially and subcutaneously in the same mice, followed by administration of the decoy receptor for RANKL, osteoprotegerin (OPG). OPG completely prevented the establishment of mixed osteolytic/osteoblastic tibial tumors, as were observed in vehicle-treated animals, but it had no effect on subcutaneous tumor growth. Consistent with the role of osteoclasts in tumor development, osteoclast numbers were elevated at the bone/tumor interface in the vehicle-treated mice compared with the normal values in the OPG-treated mice. Furthermore, OPG had no effect on CaP cell viability, proliferation, or basal apoptotic rate in vitro. These results emphasize the important role that osteoclast activity plays in the establishment of CaP skeletal metastases, including those with an osteoblastic component.

High lung volume increases stress failure in pulmonary capillaries

We previously showed that when pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to test whether stress failure occurred more frequently at high than at low lung volumes for the same Ptm. Lungs of anesthetized rabbits were inflated to a transpulmonary pressure of 20 cmH2O, perfused with autologous blood at 32.5 or 2.5 cmH2O Ptm, and fixed by intravascular perfusion. Samples were examined by both transmission and scanning electron microscopy. The results were compared with those of a previous study in which the lung was inflated to a transpulmonary pressure of 5 cmH2O. There was a large increase in the frequency of stress failure of the capillary walls at the higher lung volume. For example, at 32.5 cmH2O Ptm, the number of endothelial breaks per millimeter cell lining was 7.1 +/- 2.2 at the high lung volume compared with 0.7 +/- 0.4 at the low lung volume. The corresponding values for epithelium were 8.5 +/- 1.6 and 0.9 +/- 0.6. Both differences were significant (P less than 0.05). At 52.5 cmH2O Ptm, the results for endothelium were 20.7 +/- 7.6 (high volume) and 7.1 +/- 2.1 (low volume), and the corresponding results for epithelium were 32.8 +/- 11.9 and 11.4 +/- 3.7. At 32.5 cmH2O Ptm, the thickness of the blood-gas barrier was greater at the higher lung volume, consistent with the development of more interstitial edema. Ballooning of the epithelium caused by accumulation of edema fluid between the epithelial cell and its basement membrane was seen at 32.5 and 52.5 cmH2O Ptm. At high lung volume, the breaks tended to be narrower and fewer were oriented perpendicular to the axis of the pulmonary capillaries than at low lung volumes. Transmission and scanning electron microscopy measurements agreed well. Our findings provide a physiological mechanism for other studies showing increased capillary permeability at high states of lung inflation.

Characterization of a unique variant of bat rabies virus responsible for newly emerging human cases in North America

The silver-haired bat variant of rabies virus (SHBRV) has been identified as the etiological agent of a number of recent human rabies cases in the United States that are unusual in not having been associated with any known history of conventional exposure. Comparison of the different biological and biochemical properties of isolates of this virus with those of a coyote street rabies virus (COSRV) revealed that there are unique features associated with SHBRV. In vitro studies showed that, while the susceptibility of neuroblastoma cells to infection by both viruses was similar, the infectivity of SHBRV was much higher than that of COSRV in fibroblasts (BHK-21) and epithelial cells (MA-104), particularly when these cells were kept at 34 degrees C. At this temperature, low pH-dependent fusion and cell-to-cell spread of virus is seen in BHK-21 cells infected with SHBRV but not with COSRV. It appears that SHBRV may possess an unique cellular tropism and the ability to replicate at lower temperature, allowing a more effective local replication in the dermis. This hypothesis is supported by in vivo results which showed that while SHBRV is less neurovirulent than COSRV when administered via the intramuscular or intranasal routes, both viruses are equally neuroinvasive if injected intracranially or intradermally. Consistent with the above findings, the amino acid sequences of the glycoproteins of SHBRV and COSRV were found to have substantial differences, particularly in the region that contains the putative toxic loop, which are reflected in marked differences in their antigenic composition. Nevertheless, an experimental rabies vaccine based on the Pittman Moore vaccine strain protected mice equally well from lethal doses of SHBRV and COSRV, suggesting that currently used vaccines should be effective in the postexposure prophylaxis of rabies due to SHBRV.

Rabies virus quasispecies: implications for pathogenesis

Passage of the mouse-adapted rabies virus strain CVS-24 (where CVS is challenge virus standard) in BHK cells results in the rapid selection of a dominant variant designated CVS-B2c that differs genotypically and phenotypically from the dominant variant CVS-N2c present in mouse-brain- or neuroblastoma-cell-passaged CVS-24. The glycoprotein of CVS-B2c has 10 amino acid substitutions compared with that of CVS-N2c. Because CVS-B2c can be reproducibly selected in BHK cells, it is likely to be a conserved minor subpopulation of CVS-24. CVS-N2c is more neurotropic in vitro and in vivo than CVS-B2c, which replicates more readily in nonneuronal cells in vitro and in vivo. These characteristics appear to be relevant to the pathogenicity of the two variants. CVS-N2c is more pathogenic for adult mice than CVS-B2c. In contrast, CVS-B2c is more pathogenic for neonatal mice. These differences in pathogenicity are reflected in the selection pattern when mixtures of CVS-N2c and CVS-B2c were used to infect neonatal and adult mice. Although CVS-N2c was highly selected in adult mice, no selection for either variant was seen in neonates, suggesting that certain aspects of development, such as maturation of the nervous and immune systems, may contribute to the selection process. We speculate that the existence of different variants within a rabies virus strain may facilitate the virus in overcoming barriers to its spread, both within the host and between species.

Immunization against rabies with plant-derived antigen

We previously demonstrated that recombinant plant virus particles containing a chimeric peptide representing two rabies virus epitopes stimulate virus neutralizing antibody synthesis in immunized mice. We show here that mice immunized intraperitoneally or orally (by gastric intubation or by feeding on virus-infected spinach leaves) with engineered plant virus particles containing rabies antigen mount a local and systemic immune response. After the third dose of antigen, given intraperitoneally, 40% of the mice were protected against challenge infection with a lethal dose of rabies virus. Oral administration of the antigen stimulated serum IgG and IgA synthesis and ameliorated the clinical signs caused by intranasal infection with an attenuated rabies virus strain.

Expression of the rabies virus glycoprotein in transgenic tomatoes

We have engineered tomato plants (Lycopersicon esculentum Mill var. UC82b) to express a gene for the glycoprotein (G-protein), which coats the outer surface of the rabies virus. The recombinant constructs contained the G-protein gene from the ERA strain of rabies virus, including the signal peptide, under the control of the 35S promoter of cauliflower mosaic virus. Plants were transformed by Agrobacterium tumefaciens-mediated transformation of cotyledons and tissue culture on selective media. PCR confirmed the presence of the G-protein gene in plants surviving selection. Northern blot analysis indicated that RNA of the appropriate molecular weight was produced in both leaves and fruit of the transgenic plants. The recombinant G-protein was immunoprecipitated and detected by Western blot from leaves and fruit using different antisera. The G-protein expressed in tomato appeared as two distinct bands with apparent molecular mass of 62 and 60 kDa as compared to the 66 kDa observed for G-protein from virus grown in BHK cells. Electron microscopy of leaf tissue using immunogold-labeling and antisera specific for rabies G-protein showed localization of the G-protein to the Golgi bodies, vesicles, plasmalemma and cell walls of vascular parenchyma cells. In light of our previous demonstration that orally administered rabies G-protein from the same ERA strain elicits protective immunity in animals, these transgenic plants should provide a valuable tool for the development of edible oral vaccines.

Delineation of putative mechanisms involved in antibody-mediated clearance of rabies virus from the central nervous system

The in vitro biological activities of several rabies virus-neutralizing monoclonal antibodies (mAbs) were compared with their ability to prevent a lethal rabies virus encephalomyelitis. The protective activity of a particular mAb in vivo did not correlate with its virus-neutralizing activity in vitro; rather it was related to the mAb's ability to inhibit virus spread from cell to cell and to restrict rabies virus RNA transcription. Since treatment of rabies virus-infected cells with virus-neutralizing mAbs results in an endocytosis of the antibody, we hypothesize that an antibody may exert its inhibitory activity even after uptake by the cell. Post-exposure treatment of rats with a mAb that inhibited both virus spread and virus RNA transcription in vitro resulted in viral clearance from the central nervous system and protected the animals against a lethal rabies virus infection.

Chronic alcohol ingestion induces osteoclastogenesis and bone loss through IL-6 in mice

To investigate the role of IL-6 in alcohol-mediated osteoporosis, we measured a variety of bone remodeling parameters in wild-type (il6(+/+)) or IL-6 gene knockout (il6(-/-)) mice that were fed either control or ethanol liquid diets for 4 months. In the il6(+/+) mice, ethanol ingestion decreased bone mineral density, as determined by dual-energy densitometry; decreased cancellous bone volume and trabecular width and increased trabecular spacing and osteoclast surface, as determined by histomorphometry of the femur; increased urinary deoxypyridinolines, as determined by ELISA; and increased CFU-GM formation and osteoclastogenesis as determined ex vivo in bone marrow cell cultures. In contrast, ethanol ingestion did not alter any of these parameters in the il6(-/-) mice. Ethanol increased receptor activator of NF-kappaB ligand (RANKL) mRNA expression in the bone marrow of il6(+/+) but not il6(-/-) mice. Additionally, ethanol decreased several osteoblastic parameters including osteoblast perimeter and osteoblast culture calcium retention in both il6(+/+) and il6(-/-) mice. These findings demonstrate that ethanol induces bone loss through IL-6. Furthermore, they suggest that IL-6 achieves this effect by inducing RANKL and promoting CFU-GM formation and osteoclastogenesis.

Short-term reversibility of ultrastructural changes in pulmonary capillaries caused by stress failure

We previously showed that when the pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to determine whether some of the ultrastructural changes are rapidly reversible when the capillary pressure is reduced. To test this, the Ptm was raised to 52.5 cmH2O for 1 min of blood perfusion and then reduced to 12.5 cmH2O for 3 min of saline-dextran perfusion, followed by intravascular fixation at the same pressure. In another group of animals, the pressure was elevated for 1 min of blood and 3 min of saline-dextran before being reduced. The results were compared with previous studies in which the capillary pressures were maintained elevated at 52.5 cmH2O during the entire procedure. Control studies were also done at sustained low pressures. The results showed that the number of endothelial and epithelial breaks per millimeter and the total fraction area of the breaks were reduced when the pressure was lowered. For example, the number of endothelial breaks per millimeter decreased from 7.1 +/- 2.1 to 2.4 +/- 0.7, and the number of epithelial breaks per millimeter fell from 11.4 +/- 3.7 to 3.4 +/- 0.7. There was evidence that the breaks that closed were those that were initially small and were associated with an intact basement membrane. The results suggest that cells can move along their underlying matrix by rapid disengagement and reattachment of cell adhesion molecules, causing breaks to open or close within minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Silver-haired bat rabies virus variant does not induce apoptosis in the brain of experimentally infected mice

To examine whether induction of apoptosis plays a role in the pathogenesis of street rabies, we compared the distribution of viral antigens, histopathology, and the induction of apoptosis in the brain of mice infected with a street rabies virus (silver-haired bat rabies virus, SHBRV) and with a mouse-adapted laboratory rabies virus strain (challenge virus standard, CVS-24). Inflammation was identified in the meninges, but not in the parenchyma of the brain of mice infected with either CVS-24 or SHBRV. Necrosis was present in numerous cortical, hippocampal, and Purkinje neurons in CVS-24-infected mice, but only minimal necrosis was identified in mice infected with SHBRV. Likewise, extensive terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling (TUNEL) staining was observed in the brain of mice infected with CVS-24 but little or none in the brain of mice infected with SHBRV. Rabies virus antigens were distributed similarly in the CNS infected with either virus. However, the expression of the glycoprotein (G) is more widespread and the staining of G is generally stronger in CVS- than SHBRV-infected mice, whereas the expression of rabies virus nucleoprotein (N) is similar in mice infected with either CVS or SHBRV. The positive TUNEL staining thus correlates with the high level of G expression in CVS-infected mouse brain. Northern blot hybridization revealed that the ratio between the N and G transcripts is similar in brains infected with either virus, indicating that the reduced expression of G protein is not caused by reduced transcription in SHBRV-infected animals. Taken together, these observations suggest that apoptosis is not an essential pathogenic mechanism for the outcome of a street rabies virus infection and that other pathologic processes may contribute to the profound neuronal dysfunction characteristic of street rabies.

Crystal structure of glycine N-methyltransferase from rat liver

Glycine N-methyltransferase (GNMT) from rat liver is a tetrameric enzyme with 292 amino acid residues in each identical subunit and catalyzes the S-adenosylmethionine (AdoMet) dependent methylation of glycine to form sarcosine. The crystal structure of GNMT complexed with AdoMet and acetate, a competitive inhibitor of glycine, has been determined at 2.2 A resolution. The subunit of GNMT forms a spherical shape with an extended N-terminal region which corks the entrance of active site of the adjacent subunit. The active site is located in the near center of the spherical subunit. As a result, the AdoMet and acetate in the active site are completely surrounded by amino acid residues. Careful examination of the structure reveals several characteristics of GNMT. (1) Although the structure of the AdoMet binding domain of the GNMT is very similar to those of other methyltransferases recently determined by X-ray diffraction method, an additional domain found only in GNMT encloses the active site to form a molecular basket, and consequently the structure of GNMT looks quite different from those of other methyltransferases. (2) This unique molecular structure can explain why GNMT can capture folate and polycyclic aromatic hydrocarbons. (3) The unique N-terminal conformation and the subunit structure can explain why GNMT exhibits positive cooperativity in binding AdoMet. From the structural features of GNMT, we propose that the enzyme might be able to capture yet unidentified molecules in the cytosol and thus participates in various biological processes including detoxification of polycyclic aromatic hydrocarbons. In the active site, acetate binds near the S-CH3 moiety of AdoMet. Simple modeling indicates that the amino group of the substrate glycine can be placed close to the methyl group of AdoMet within 3.0 A and form a hydrogen bond with the carboxyl group of Glu15 of the adjacent subunit. On the basis of the ternary complex structure, the mechanism of the methyl transfer in GNMT has been proposed.

Alveolar hypoxia increases gene expression of extracellular matrix proteins and platelet-derived growth factor-B in lung parenchyma

The walls of pulmonary capillaries are extremely thin, and wall stress increases greatly when capillary pressure rises. Alveolar hypoxia causes pulmonary vasoconstriction and hypertension, and if this is uneven, some capillaries may be exposed to high transmural pressure and develop stress failure. There is evidence that increased wall stress causes capillary remodeling. In this study we exposed Madison strain Sprague-Dawley rats to normobaric hypoxia (10% oxygen) for 6 h or 3 d (short-term group), and for 3 d or 10 d (long-term group). Peripheral lung tissue was then collected and messenger RNA (mRNA) levels were determined for extracellular matrix (ECM) proteins and growth factors. Collagen content (hydroxyproline) was also measured. Levels of mRNA for alpha2(IV) procollagen increased sixfold after 6 h of hypoxia and sevenfold after 3 d of hypoxia, and then decreased after 10 d exposure. Levels of mRNA for platelet-derived growth factor-B (PDGF-B) doubled after 6 h of hypoxia but returned to control values after 3 d. mRNA levels for alpha1(I) and alpha1(III) procollagens and fibronectin were increased after 3 d of hypoxia (by seven- to 12-fold, 1.6- to eightfold, and 12-fold, respectively), then decreased toward control values after 10 d. In contrast, neither levels of mRNA for vascular endothelial growth factor (VEGF) nor collagen content changed. These results suggest that alveolar hypoxia causes vascular remodeling in lung parenchyma, and are consistent with capillary wall remodeling in response to increased wall stress.

Pulmonary microvascular permeability. Responses to high vascular pressure after induction of pacing-induced heart failure in dogs

The pressure threshold for injury of pulmonary capillaries is approximately 50 to 55 cm H2O in the canine lung, as measured by changes in the filtration coefficient (Kf,c). Since the pulmonary endothelial basement membrane has been observed to thicken in patients with heart failure and pulmonary venous hypertension, we hypothesized that both baseline permeability and the threshold for high-vascular-pressure injury would be altered as a result. Dogs (n = 12) were chronically paced at 245 beats per minute for approximately 4 weeks, then were paced at 225 beats per minute for an additional 3 weeks. Lung lobes from anesthetized paced dogs and additional control dogs (n = 14) were then isolated, ventilated, and perfused with blood. Although vascular resistance was increased nearly threefold and vascular compliance reduced by 50% in the paced group, Kf,c referenced to 1 g blood-free dry weight was no different from control. Despite this lack of difference at normal pulmonary vascular pressures, several significant results were obtained. First, in the paced group there was a significant increase in the threshold for high-vascular-pressure injury: Kf,c measured at pulmonary vascular pressures commonly seen in heart failure (20 to 50 cm H2O) were significantly less in this group compared with control. Model predictions showed that in vivo, this difference in Kf,c would result in a 50% reduction in the amount of water and protein cleared across the pulmonary capillary endothelial barrier in the paced group.(ABSTRACT TRUNCATED AT 250 WORDS)

Severity of neurological signs and degree of inflammatory lesions in the brains of rats with Borna disease correlate with the induction of nitric oxide synthase

The putative role of nitric oxide in the neuropathogenesis of Borna disease was investigated by determining changes in the expression of inducible nitric oxide synthase (iNOS) mRNA and constitutively expressed NOS (cNOS) mRNA in brains of Borna disease virus (BDV)-infected rats. iNOS mRNA was not detected in normal rat brain but was identified in BDV-infected brain at 14 days postinfection (p.i.), reaching maximum levels at 21 days p.i., when neurological signs and inflammatory reactions in the brain were also at a peak. cNOS mRNA was expressed in both normal brain and infected brain, increasing markedly at 17 days p.i. and reaching a peak at 21 days p.i. In situ hybridization analysis revealed iNOS mRNA in some, but not all, BDV-infected regions of the brain, particularly in the basolateral cortex and the hippocampus. iNOS-positive cells, as identified immunohistologically, were preferentially localized in perivascular areas of the hippocampus and in outer cortical layers. These iNOS-positive cells resembled monocytes/macrophages in morphology and distribution pattern but were significantly fewer. The correlation of iNOS and cNOS mRNA expression with the development of neurological disease, as well as the enhanced expression of iNOS within brain regions with inflammatory lesions, strongly suggests that NO may contribute to pathogenesis of Borna disease.

Nutritional and hormonal factors control the gene expression of FoxOs, the mammalian homologues of DAF-16

Transcription factors of the FoxO family in mammals are orthologues of the Caenorhabditis elegans forkhead factor DAF-16, which has been characterized as a target of insulin-like signalling. Three members of this family have been identified in rodents: FoxO1, FoxO3 and FoxO4, originally termed FKHR, FKHRL1 and AFX respectively. A number of in vitro studies have revealed that FoxOs are regulated through phosphorylation in response to insulin and related growth factors, resulting in their nuclear exclusion and inactivation. To clarify the mechanisms involved in the regulation of these factors in vivo, we investigated in the present study whether or not, and if so how, their mRNA levels in rat liver respond to the stimuli of several nutritional and hormonal factors. Imposed fasting for 48 h significantly elevated mRNA levels of FoxO1 (1.5-fold), FoxO3 (1.4-fold), and FoxO4 (1.6-fold). Refeeding for 3 h recovered the induced mRNA levels of FoxO1 and FoxO3 to the control levels, but did not affect that of FoxO4. FoxO1 and FoxO4 mRNA levels were proved to be highly reflective of their protein levels measured by Western immunoblotting. Of the three FoxO genes, FoxO4 only showed altered levels of mRNA (a 1.5-fold increase) in response to a protein-free diet. Streptozotocin-induced diabetes for 28 days decreased hepatic mRNA levels of FoxO1 and FoxO3 and increased the level of FoxO4 mRNA, but short-term (7 days) diabetes had fewer effects on the expression of these genes. Insulin replacement partially restored the FoxO1 and FoxO4 mRNA levels, but had no effect on the FoxO3 mRNA level. Daily administration for 1 week of dexamethasone, a synthetic glucocorticoid, increased the mRNA levels of FoxO1 (1.8-fold) and FoxO3 (2.4-fold). These results show that the FoxO genes respond differently to nutritional and hormonal factors, suggesting a new mechanism for the regulation of FoxO-dependent gene expression by these factors. Moreover, changes of FoxO1 and FoxO4 in the nucleus in response to fasting also suggest that the regulation of nucleus/cytoplasm translocation actually functions in vivo.

Detection of Borna disease virus-reactive antibodies from patients with affective disorders by western immunoblot technique

Borna disease (BD) virus is a partially characterized neurotropic agent with a predilection for neurons and astrocytes in the limbic system and cerebrum of infected hosts. Although it usually causes a fatal encephalitis, some laboratory animals which have been experimentally inoculated can develop a persistent non-fatal infection characterized by a neuro-behavioral syndrome akin to human manic-depression. Using immunofluorescent techniques, we previously observed BD virus-specific antibodies in the sera of 4.5% of affectively ill patients, with the highest titers present in bipolar patients. More recently, we have developed a sensitive Western blot assay for the detection of anti-BD virus antibodies to a 38/40 kDa and 24 kDa protein in human serum. In the present study, we screened 138 affectively ill patients and 117 healthy controls and observed a significantly great proportion of patients with antibodies to the 38/40 kDa protein (P < 0.0001), the 24 kDa protein (P < 0.05) and both the 38/40 kDa and 24 kDa proteins (P < 0.025). These data extend prior reports on the presence of BD virus-specific antibodies in psychiatric patients, and suggest that a BD virus-like agent may be associated with affective illness in humans.

Chiral P,N-ligands based on ketopinic acid in the asymmetric Heck reaction

[figure: see text] Novel chiral P,N-ligands were synthesized from (1S)-(+)-ketopinic acid using palladium-catalyzed coupling reaction of a vinyl triflate and either a diarylphosphine or a dialkylphosphine as the key step. Palladium complexes of these ligands are efficient catalysts for asymmetric Heck reaction between aryl or alkenyl triflates and cyclic alkenes. Products were obtained with good to excellent enantioselectivity from arylation and alkenylation of 1,2-dihydrofuran, cyclopentene, and 4,7-dihydro-1,3-dioxepin.

Very high pressures are required to cause stress failure of pulmonary capillaries in thoroughbred racehorses

Thoroughbred horses develop extremely high pulmonary vascular pressures during galloping, all horses in training develop exercise-induced pulmonary hemorrhage, and we have shown that this is caused by stress failure of pulmonary capillaries. It is known that the capillary transmural pressure (Ptm) necessary for stress failure is higher in dogs than in rabbits. The present study was designed to determine this value in horses. The lungs from 15 Thoroughbred horses were perfused with autologous blood at Ptm values (midlung) of 25, 50, 75, 100 and 150 mmHg, and then perfusion fixed, and samples (dorsal and ventral, from caudal region) were examined by electron microscopy. Few disruptions of capillary endothelium were observed at Ptm < or = 75 mmHg, and 5.3 +/- 2.2 and 4.3 +/- 0.7 breaks/mm endothelium were found at 100 and 150 mmHg Ptm, respectively. Blood-gas barrier thickness did not change with Ptm. At low Ptm, interstitial thickness was greater than previously found in rabbits but not in dogs. We conclude that the Ptm required to cause stress failure of pulmonary capillaries is between 75 and 100 mmHg and is greater in Thoroughbred horses than in both rabbits and dogs.

High lung inflation increases mRNA levels of ECM components and growth factors in lung parenchyma

Remodeling of pulmonary capillaries occurs after chronic increases in capillary pressure (e.g., mitral stenosis). Also, remodeling of pulmonary arteries begins within 4 h of increased wall stress and is endothelium dependent. We have previously shown that high lung inflation increases wall stress in pulmonary capillaries. This study was designed to determine whether high lung inflation induces remodeling of the extracellular matrix (ECM) in lung parenchyma. Open-chest rabbits were ventilated for 4 h with 9-cmH2O positive end-expiratory pressure (PEEP) on one lung and 1-cmH2O PEEP on the other (High-PEEP group), or with 2-cmH2O PEEP on both lungs (Low-PEEP group). An additional untreated control group was also included. We found increased levels of mRNA in both lungs of High-PEEP rabbits (compared with both the Low-PEEP and untreated groups) for alpha1(III) and alpha2(IV) procollagen, fibronectin, basic fibroblast growth factor, and transforming growth factor-beta1. In contrast, alpha2(I) procollagen and vascular endothelial growth factor mRNA levels were not changed. We conclude that high lung inflation for 4 h increases mRNA levels of ECM components and growth factors in lung parenchyma.

Differential effects of rabies and borna disease viruses on immediate-early- and late-response gene expression in brain tissues

In situ hybridization and Northern blot analysis were used to examine expression of the immediate-early-response genes (IEGs) egr-1, junB, and c-fos, and the late response gene encoding enkephalin in the brains of rats infected intranasally with Borna disease virus (BDV) or rabies virus. In both Borna disease and rabies virus infections, a dramatic and specific induction of IEGs was detected in particular regions of the hippocampus and the cortex. Increased IEG mRNA expression overlapped with the characteristic expression patterns of BDV RNA and rabies virus RNA, although relative expression levels of viral RNA and IEG mRNA differed, particularly in the hippocampal formation. Furthermore, the temporal relationship between viral RNA synthesis and activation of IEG mRNA expression in BDV infection differed markedly from that in rabies virus infection, suggesting that IEG expression is upregulated by different mechanisms. Expression of proenkephalin (pENK) mRNA was also significantly increased in BDV infection, whereas in rabies virus infection, pENK mRNA levels and also the levels of glyceraldehyde-3-phosphate dehydrogenase mRNA were reduced at terminal stages of the disease, probably reflecting a generalized suppression of cellular protein synthesis due to massive production of rabies virus mRNA. The correlation between activated IEG mRNA expression and the strong increase in viral RNA raises the possibility that IEG products induce some phenotypic changes in neurons that render them more susceptible to viral replication.

Successful transplantation of porcine livers after warm ischemic insult in situ and cold preservation including postconditioning with gaseous oxygen

BACKGROUND

In order to reduce the shortage of viable donor livers for organ transplantation, a method has been developed that allows even predamaged livers from nonheartbeating donors to be used as transplantable organs.

METHODS

Porcine livers were harvested 45 min after cardiac arrest of the nonheparinized donor, preflushed with heparinized saline solution, and subsequently rinsed with University of Wisconsin solution, to which superoxide dismutase was added as an oxygen free radical scavenger. Thereafter, the livers were persufflated with gaseous oxygen via the venous vascular system while immersed in University of Wisconsin solution at 4 degrees C for 4 to 5 hr.

RESULTS

After orthotopic transplantation, all of the livers conditioned with gaseous oxygen were able to support life-sustaining function during the whole observation period of 7 days post transplantation, while no survival of the recipients could be obtained without the described treatment.

CONCLUSIONS

The present study establishes a new perspective for the use of ischemically altered livers from nonheartbeating donors for organ transplantation under clinical circumstances.