Myostatin induces mitochondrial metabolic alteration and typical apoptosis in cancer cells

Myostatin, a member of the transforming growth factor-β superfamily, regulates the glucose metabolism of muscle cells, while dysregulated myostatin activity is associated with a number of metabolic disorders, including muscle cachexia, obesity and type II diabetes. We observed that myostatin induced significant mitochondrial metabolic alterations and prolonged exposure of myostatin induced mitochondria-dependent apoptosis in cancer cells addicted to glycolysis. To address the underlying mechanism, we found that the protein levels of Hexokinase II (HKII) and voltage-dependent anion channel 1 (VDAC1), two key regulators of glucose metabolisms as well as metabolic stress-induced apoptosis, were negatively correlated. In particular, VDAC1 was dramatically upregulated in cells that are sensitive to myostatin treatment whereas HKII was downregulated and dissociated from mitochondria. Myostatin promoted the translocation of Bax from cytosol to mitochondria, and knockdown of VDAC1 inhibited myostatin-induced Bax translocation and apoptosis. These apoptotic changes can be partially rescued by repletion of ATP, or by ectopic expression of HKII, suggesting that perturbation of mitochondrial metabolism is causally linked with subsequent apoptosis. Our findings reveal novel function of myostatin in regulating mitochondrial metabolism and apoptosis in cancer cells.

Expression of rat bone sialoprotein promoter in transgenic mice

Bone sialoprotein (BSP) is a major protein of the mineralized bone extracellular matrix that has been implicated in the nucleation of hydroxyapatite crystals. Our previous studies have demonstrated that BSP mRNA is expressed by differentiated osteoblasts, odontoblasts, and cementoblasts involved in de novo mineralized tissue formation in a tissue-specific and developmentally regulated manner. To determine the basis of the selective expression of the BSP gene, we have generated four transgenic mouse lines in which 2.7 kb of the rat BSP promoter ligated to a luciferase reporter gene has been stably integrated into the mouse genome. Assays of luciferase activities in 5-day-old animals has revealed consistently high levels in bone tissues with negligible activities in various other organs including kidney, liver, stomach, intestine, and spleen. In some animals, variable expression was observed in brain and skin. Temporal analyses revealed the highest luciferase expression in neonatal bones, with expression decreasing markedly with subsequent growth and development, as observed previously for the endogenous gene in rats. Immunohistochemical analysis of luciferase activity and in situ hybridization of luciferase mRNA in bone tissues show that differentiated osteoblasts express the highest levels of luciferase, consistent with the induction of endogenous gene expression. These studies demonstrate that the regulation of the BSP gene during osteoblastic differentiation, together with its tissue-specific, developmentally regulated expression, is primarily mediated within the 2.7 kb region of the promoter.

Predominant etiology of adnexal torsion and ovarian outcome after detorsion in premenarchal girls

BACKGROUND/PURPOSE

Consensus has not been reached regarding the treatment of ovarian torsion in premenarchal girls. If viable adnexa can be salvaged, the future reproductive potential of the girl is maximized. The authors determined the predominant etiology, evaluated the restoration of ovarian function and anatomic structure postoperatively in premenarchal girls with adnexal torsion, and discuss the most appropriate treatment.

METHODS

Sixty-six premenarchal girls with twisted adnexa underwent salpingoophorectomy (27 cases), or detorsion and adnexal conservation surgery (39 cases), according to the extent of adnexal damage found intraoperatively. These patients' data were collected and analyzed. The typical presentation, predominant etiology, surgical outcome, and restoration of ovarian function postoperatively were investigated.

RESULTS

Of all torsive ovaries, histopathology verified that 2 (3.0%) cases were malignant, 8 (12.1%) cases were normal, and 56 (84.9%) cases were benign. After operation and menarche, ultrasound showed that the involved ovaries were of normal size with normal follicular development in 33 of the 35 (94.3%) patients who received detorsion and adnexal conservation surgery. In the remaining two (5.7%) of the 35 detorsion patients, the affected ovaries were atrophied (small sized) and there was no ultrasound evidence of follicular development.

CONCLUSIONS

Premenarchal girls with adnexal torsion more commonly had a benign ovarian tumor or no underlying abnormality as an etiology; ovarian malignancy was rare. In the management of these cases, detorsion and adnexal conservation surgery should be considered in cases with adnexa appearing to be ischemic or hemorrhagic infarction.

Requirement of cysteines and length of the human respiratory syncytial virus M2-1 protein for protein function and virus viability

The M2-1 protein of human respiratory syncytial virus (hRSV) promotes processive RNA synthesis and readthrough at RSV gene junctions. It contains four highly conserved cysteines, three of which are located in the Cys(3)-His(1) motif at the N terminus of M2-1. Each of the four cysteines, at positions 7, 15, 21, and 96, in the M2-1 protein of hRSV A2 strain was individually replaced by glycines. When tested in an RSV minigenome replicon system using beta-galactosidase as a reporter gene, C7G, C15G, and C21G located in the Cys(3)-His(1) motif showed a significant reduction in processive RNA synthesis compared to wild-type (wt) M2-1. C96G, which lies outside the Cys(3)-His(1) motif, was fully functional in supporting processive RNA synthesis in vitro. Each of these cysteine substitutions was introduced into an infectious antigenomic cDNA clone derived from hRSV A2 strain. Except for C96G, which resulted in a viable virus, no viruses were recovered with mutations in the Cys(3)-His(1) motif. This indicates that the Cys(3)-His(1) motif is critical for M2-1 function and for RSV replication. The functional requirement of the C terminus of the M2-1 protein was examined by engineering premature stop codons that caused truncations of 17, 46, or 67 amino acids from the C terminus. A deletion of 46 or 67 amino acids abolished the synthesis of full-length beta-galactosidase mRNA and did not result in the recovery of viable viruses. However, a deletion of 17 amino acids from the C terminus of M2-1 reduced processive RNA synthesis in vitro and was well tolerated by RSV. Relocation of the M2-1 termination codon upstream of the M2-2 initiation codons did not significantly affect the expression of the M2-2 protein. Both rA2-Tr17 and rA2-C96G did not replicate as efficiently as wt rA2 in HEp-2 cells and was restricted in replication in the respiratory tracts of cotton rats.

An essential role for CCAAT/enhancer binding protein beta in bleomycin-induced pulmonary fibrosis

Pulmonary fibrosis is characterized by inflammation, genesis of myofibroblasts, and abnormal tissue repair. Despite extensive research, its pathogenesis remains incompletely understood. Previously, the transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) was found to be a key regulator of myofibroblast differentiation in vitro, and to be involved in the acute phase and inflammatory responses. In an attempt to test the role of C/EBPbeta in the development of pulmonary fibrosis, experiments using C/EBPbeta null mice and their wild-type littermates were conducted. Our findings indicated that, compared to wild-type mice, animals deficient in C/EBPbeta showed significantly reduced fibrotic lesions and collagen deposition in the lung upon endotracheal injection of bleomycin. Further studies on the mechanisms by which C/EBPbeta regulates fibrosis indicated that knockout of C/EBPbeta attenuates inflammatory cytokine expression in bleomycin-treated mice. The reduced alpha-smooth muscle actin gene expression in either isolated lung fibroblasts or lung tissue from bleomycin or saline-treated C/EBPbeta deficient mice suggests that C/EBPbeta regulates myofibroblast differentiation during fibrosis. Consistent with this finding, cells from C/EBPbeta deficient mice exhibited higher proliferative rates than those from wild-type mice. These data suggest that C/EBPbeta plays an essential role in pulmonary fibrosis and that this role appears to be multifactorial with respect to cytokine expression, cell differentiation, and proliferation.

Altered expression of bone sialoproteins in vitamin D-deficient rBSP2.7Luc transgenic mice

Bone sialoprotein (BSP) and osteopontin (OPN) are two major noncollagenous matrix proteins in mineralized connective tissue that have discrete roles in bone matrix formation, mineralization, and remodeling. The osteotropic secosteroid, 1,25-dihydroxyvitamin D3, a potent regulator of bone remodeling required for normal bone development, has been shown to exert differential effects on OPN and BSP expression by bone cells in vitro. To investigate these effects in vivo, we induced vitamin D3 deficiency in a transgenic mouse line (rBSP2.7Luc) that has a 2.7 kb rat BSP promoter linked to a luciferase reporter gene in its genome. Pregnant rBSP2.7Luc mice were fed vitamin D3-deficient food and demineralized water for 6 weeks. Their offspring were weaned at 3 weeks of age and then fed vitamin D-deficient food for an additional week. The control group were fed normal rodent pellets and water during the entire experimental procedure. Bone tissues from 40, 4-week-old offspring in each group were analyzed for BSP, OPN and luciferase expression. Vitamin D3-deficient mice displayed a rachitic phenotype that included reduced size and malformation of bones. Assays of the BSP promoter transgene in calvariae, mandibles, and tibiae of the rachitic mice showed increases in luciferase activity of 3.1-, 1.9-, and 4.6-fold, respectively, when compared with control littermates. Semiquantitative reverse transcriptase polymerase chain reaction assays of BSP mRNA revealed increases of 7-, 74-, and 66-fold, respectively, in the same rachitic bones, while OPN mRNA was reduced 12.5-fold in calvariae and 2-fold in tibiae and mandibles. In situ hybridization using mouse cRNA probes revealed that the increased BSP expression and decreased OPN expression in the vitamin D3-deficient mice was primarily in osteoblastic cells on the surface of calvariae and endosteal spaces of alveolar bone, on newly formed epiphyseal bone, and in cementoblasts and in hypertrophic chondrocytes. These studies are the first to show that BSP and OPN are differentially regulated by vitamin D3 in vivo, reflecting the diverse roles of these protein in bone remodeling. Moreover, the increased expression of the BSP transgene in the rachitic mice demonstrates that vitamin D3 regulation of BSP expression is mediated, in part, by element(s) within the 2.7 kb promoter region.

SS18-SSX2 and the mitochondrial apoptosis pathway in mouse and human synovial sarcomas

Synovial sarcoma is a deadly malignancy with limited sensitivity to traditional cytotoxic chemotherapy. SS18-SSX fusion oncogene expression characterizes human synovial sarcomas and drives oncogenesis in a mouse model. Elevated expression of BCL2 is considered a consistent feature of the synovial sarcoma expression profile. Our objective was to evaluate the expression of apoptotic pathway members in synovial sarcomas and interrogate the impact of modulating SS18-SSX expression on this pathway. We show in human and murine synovial sarcoma cells that SS18-SSX increases BCL2 expression, but represses other anti-apoptotic genes, including MCL1 and BCL2A1. This repression is achieved by directly suppressing expression via binding through activating transcription factor 2 (ATF2) to the cyclic adenosine monophosphate (AMP) response element (CRE) in the promoters of these genes and recruiting TLE1/Groucho. The suppression of these two anti-apoptotic pathways silences the typical routes by which other tumors evade BH3-domain peptidomimetic pharmacotherapy. We show that mouse and human synovial sarcoma cells are sensitive in vitro to ABT-263, a BH3-peptidomimetic, much more than the other tested cancer cell lines. ABT-263 also enhances the sensitivity of these cells to doxorubicin, a traditional cytotoxic chemotherapy used for synovial sarcoma. We also demonstrate the capacity of ABT-263 to stunt synovial sarcomagenesis in vivo in a genetic mouse model. These data recommend pursuit of BH3-peptidomimetic pharmacotherapy in human synovial sarcomas.

Prostaglandin F2 alpha induces cardiac myocyte hypertrophy in vitro and cardiac growth in vivo

Several prostaglandins [prostaglandin (PG) A2, -B2, -D2, -E2, -F2 alpha, and -I2 and carbaprostacyclin] and the thromboxane analogue U-46619 were analyzed for the ability to induce hypertrophy of rat neonatal cardiac ventricular myocytes. Myocyte hypertrophy was induced specifically by PGF2 alpha. Myocytes exposed to this prostanoid in culture increased in size and protein content. The contractile fibrils within the cells became organized into parallel arrays, and the cells tended to cluster and beat spontaneously. PGF2 alpha also induced the expression of c-fos, atrial natriuretic factor (ANF), and alpha-skeletal actin in these cells. The effects of PGF2 alpha were compared with several known cardiac myocyte hypertrophy factors (phenylephrine, endothelin-1, leukemia inhibitory factor, cardiotrophin-1, and angiotensin II). PGF2 alpha was found to be intermediate in potency among the factors but induced a level of ANF production that was approximately 10-fold higher than any of the other effectors. Responsiveness to PGF2 alpha was not limited to neonatal cardiocytes. Ventricular myocytes isolated from adult rats also responded specifically to PGF2 alpha with a morphological change similar to that observed with phenylephrine and by producing ANF. In rats, chronic administration of fluprostenol, a potent agonist analogue of PGF2 alpha, resulted in a dose-dependent increase in heart weight- and ventricular weight-to-body weight ratios. The amount of PGF2 alpha extractable from the hearts of rats with cardiac hypertrophy induced by myocardial infarction was also found to be greater than that in sham-operated control rats. These results indicate that PGF2 alpha may play an important role in inducing cardiac hypertrophy.

Elimination of palmitoylation sites in the human dopamine D1 receptor does not affect receptor-G protein interaction

We have eliminated putative palmitoylation sites in the carboxyl tail of the human dopamine D1 receptor by replacing the two cysteine residues with alanines either separately or together. The wild type and the three mutated dopamine D1 receptors were stably expressed in baby hamster kidney cells and characterized to detect any resulting alterations in receptor-G protein interactions. The three mutant dopamine D1 receptors retained the same proportion of high affinity state for agonists as wild type receptors and also no difference was observed in the stimulation of adenylyl cyclase activity. Our results are in contrast to those observed with the beta 2-adrenoceptor and consistent with similar studies of luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptors, alpha 2-adrenoceptors, muscarinic M2 receptors and thyrotropin releasing hormone (TRH) receptors. Thus, we suggest that palmitoylation appears to play a unique role in the beta 2-adrenoceptors, and appears not to be essential in G protein coupling for the dopamine D1 receptors.

Production of AMP and adenosine in the interstitial fluid compartment of the isolated perfused normoxic guinea pig heart

The pathway of production of AMP and adenosine in the myocardial interstitial fluid compartment was studied in the isolated perfused normoxic guinea pig heart by collecting the transmyocardial effluent (t.m.e.) with the method of De Deckere and Ten Hoor (1977). Besides adenosine and inosine, AMP was found in t.m.e. Infusion of alpha,beta-methylene adenosine 5'-diphosphate (AOPCP), a specific inhibitor of the ecto 5'-nucleotidase, resulted in increases in t.m.e. AMP and inosine and a decrease in adenosine. Infusion of acetate producing a nearly twofold increase in myocardial AMP content did not increase the t.m.e. AMP even in the presence of AOPCP. In preparations made from 6-OH dopamine treated animals, the t.m.e. adenosine and inosine were reduced and AOPCP produced smaller increases in AMP and inosine, indicating that most if not all of the t.m.e. AMP originated from the sympathetic nerve terminals. Infusions of beta,gamma-imidoadenosine and beta,gamma-methylene adenosine 5'-triphosphate (AMPPNP and AMPPCP), non-hydrolysable analogs of ATP, resulted in dose-dependent increases in the t.m.e. AMP, which were much augmented in the presence of AOPCP. AMPPNP produced similar effects in 6-OH dopamine-treated preparations. As AMPPNP and AMPPCP are good substrates of ATP pyrophosphohydrolase, these findings indicate the presence of ATP pyrophosphohydrolase in the myocardial interstitial space.

Intraspinal grafting of fibroblasts genetically modified by recombinant adenoviruses

Intracerebral or intraspinal grafting of genetically modified primary fibroblasts has been shown to enhance functional recovery in several models of CNS disease, including spinal cord injury. Most of these studies utilized retrovirus vectors. In this report, we describe in vitro conditions for genetically modifying primary fibroblasts with recombinant adenovirus vectors carrying the lacZ or green fluorescent protein (GFP) genes. As intraspinal allografts in animals immunosuppressed by cyclosporin A, the genetically modified cells survived and expressed the transgenes for at least 2 months. We conclude that recombinant adenovirus vectors are efficient and convenient tools for ex vivo gene therapy in the CNS.

Estimating influences of unemployment and underemployment on mental health during the COVID-19 pandemic: who suffers the most?

OBJECTIVES

The aim of the study was to evaluate whether unemployment and underemployment are associated with mental distress and whether employment insecurity and its mental health consequences are disproportionately concentrated among specific social groups in the United States during the COVID-19 pandemic.

STUDY DESIGN

This is a population-based longitudinal study.

METHODS

Data came from the Understanding America Study, a population-based panel in the United States. Between April and May 2020, 3548 adults who were not out of the labor force were surveyed. Analyses using targeted maximum likelihood estimation examined the association of employment insecurity with depression, assessed using the 2-item Patient Health Questionnaire, and anxiety, measured with the 2-item Generalized Anxiety Disorder scale. Stratified models were evaluated to examine whether employment insecurity and its mental health consequences are disproportionately concentrated among specific social groups.

RESULTS

Being unemployed or underemployed was associated with increased odds of having depression (adjusted odds ratio [AOR] = 1.66, 95% confidence interval [CI] = 1.36-2.02) and anxiety (AOR = 1.50, 95% CI = 1.26, 1.79), relative to having a full-time job. Employment insecurity was disproportionately concentrated among Hispanics (54.3%), Blacks (60.6%), women (55.9%), young adults (aged 18-29 years; 57.0%), and those without a college degree (62.7%). Furthermore, Hispanic workers, subsequent to employment insecurity, experienced worse effects on depression (AOR = 2.08, 95% CI = 1.28, 3.40) and anxiety (AOR = 1.95, 95% CI = 1.24, 3.09). Those who completed high school or less reported worse depression subsequent to employment insecurity (AOR = 2.44, 95% CI = 1.55, 3.85).

CONCLUSIONS

Both unemployment and underemployment threaten mental health during the pandemic, and the mental health repercussions are not felt equally across the population. Employment insecurity during the pandemic should be considered an important public health concern that may exacerbate pre-existing mental health disparities during and after the pandemic.

Synelfin regulation during the critical period for song learning in normal and isolated juvenile zebra finches

Male zebra finches (Taeniopygia guttata) learn to sing during a critical period in adolescence. We previously described a presynaptic protein, synelfin, whose mRNA is increased early in this critical period in a brain nucleus specifically implicated in song learning, lateral MAN (lMAN). In the current study, in situ hybridization was used to map this change in gene expression to the subregion of lMAN that projects to the robust nucleus of the archistriatum (RA), the principal motor output of the telencephalic circuit that controls song production. Using confocal immunofluorescence microscopy, we detected numerous puncta of synelfin immunoreactivity that apparently represent presynaptic terminals from lMAN in the RA of young males. Synelfin immunoreactivity in RA declined abruptly between 40 and 45 days of age, a time of major synaptic reorganization in RA. This change did not occur until about 10 days after the decline in synelfin mRNA in cell bodies within lMAN, indicating a relatively slow turnover of the protein in presynaptic terminals and suggesting that some of the functional changes that occur during the critical period may arise from regulatory decisions that were initiated a week or more earlier. Depriving birds of tutoring did not halt or delay the decline of synelfin mRNA in lMAN. This change in gene expression must not be a consequence of early song learning, but may reflect an innate or programmed step in song circuit development.

Prevalence and extent of right-to-left shunt in migraine: a survey of 217 Chinese patients

BACKGROUND

Recently, contrast-enhanced transcranial Doppler (cTCD) studies have shown that right-to-left shunt (RLS) may be a risk factor for migraine in Westerners; however, limited data in the literature describes the prevalence of RLS in Chinese patients with migraine.

OBJECTIVE

To assess the prevalence of RLS in patients with migraine in China and to evaluate the relationship between the extent of RLS and migraine.

METHODS

A total of 217 consecutive patients with a diagnosis of migraine and 100 volunteers were recruited. cTCD was used to assess the prevalence and the extent of RLS in all subjects.

RESULTS

In the migraine group, the rate of positive RLS was 44.2% (96/217), with 23.5% (51/217) of these being large. In the healthy group, 28.0% (28/100) were positive for RLS overall, and 5.0% (5/100) were large (P = 0.006; P < 0.001). In patients having migraines with aura (MwA), 66.1% (39/59) were positive for RLS overall, and 37.3% (22/59) were large, which was significantly higher when compared with the healthy group (P < 0.001; P < 0.001); in patients having migraines without aura (MwoA), 36.1% (57/158) were positive for RLS overall, and 18.4% (29/158) were large, which was against significantly higher (P < 0.001; P = 0.003). In the MwoA group, the large RLS rate was also higher than in the healthy group (P = 0.002).

CONCLUSIONS

A close correlation has been documented between RLS and migraine, especially MwA, but these relationships exist only when the shunts were large.

Structural studies of Escherichia coli UDP-N-acetylmuramate:L-alanine ligase

Uridine diphosphate N-acetylmuramate:L-alanine ligase (EC 6.3.2.8, UNAM:L-Ala ligase or MurC gene product) adds the first amino acid to the sugar moiety of the peptidoglycan precursor, catalyzing one of the essential steps in cell wall biosynthesis for both gram-positive and gram-negative bacteria. Here, we report our studies on the secondary and quaternary structures of UNAM:L-Ala ligase from Escherichia coli. The molecular weight of the purified recombinant enzyme determined by electrospray ionization mass spectrometry agreed well with the molecular weight deduced from the DNA sequence. Through sedimentation equilibrium analysis, we show that the enzyme exists in equilibrium between monomeric and dimeric forms and that the dissociation constant of the dimer, Kd, was determined to be 1.1 +/- 0.4 microM at 37 degrees C and 0.58 +/- 0.30 microM at 4 degrees C. A very similar Kd value was also obtained at 37 degrees C by gel filtration chromatography. The secondary structure of the enzyme was characterized by circular dichroism spectroscopy. No change in the secondary structure was observed between the monomeric and dimeric forms of the enzyme. The activity assays at enzyme concentrations both below and above the determined Kd value lead to the conclusion that the enzyme is active both as dimers and as monomers and that the specific activity is independent of the oligomerization state.

Expression of functional Bunyamwera virus L protein by recombinant vaccinia viruses

A cDNA containing the complete coding sequence of the Bunyamwera virus (family Bunyaviridae) L genome segment has been constructed and cloned into two recombinant vaccinia virus expression systems. In the first, the L gene is under control of vaccinia virus P7.5 promoter; in the second, the L gene is under control of the bacteriophage T7 phi 10 promoter, and expression of the L gene requires coinfection with a second recombinant vaccinia virus which synthesizes T7 RNA polymerase. Both systems express a protein which is the same size as the Bunyamwera virus L protein and is recognized by a monospecific L antiserum. The expressed L protein was shown to be functional in synthesizing Bunyamwera virus RNA in a nucleocapsid transfection assay: recombinant vaccinia virus-infected cells were transfected with purified Bunyamwera virus nucleocapsids, and subsequently, total cellular RNA was analyzed by Northern (RNA) blotting. No Bunyamwera virus RNA was detected in control transfections, but in cells which had previously been infected with recombinant vaccinia viruses expressing the L protein, both positive- and negative-sense Bunyamwera virus S segment RNA was detected. The suitability of this system to delineate functional domains within the Bunyamwera virus L protein is discussed.

Upregulation of T-bet expression in peripheral blood mononuclear cells during Vogt-Koyanagi-Harada disease

AIM

To test the hypothesis that T-bet expression is altered in patients with Vogt-Koyanagi-Harada (VKH) disease.

METHODS

Peripheral blood was withdrawn from 16 VKH patients before and after immunosuppressive treatment and from 16 healthy individuals. IFN-gamma, IL-2, and IL-4 in the serum and the supernatants of peripheral blood mononuclear cells (PBMC) cultured with or without phytohaemagglutinin (PHA) were measured by ELISA. T-bet mRNA and protein expression in PBMC cultured with or without PHA was detected by RT-PCR and western blot, respectively.

RESULTS

The level of IFN-gamma, but not IL-2 and IL-4, was significantly higher in the supernatants of stimulated PBMC in patients than in controls. A significantly increased T-bet mRNA was found in VKH patients during an active uveitis episode, but not in quiescent patients, compared to controls. T-bet protein was detectable in VKH patients during an active uveitis episode, but not in quiescent patients nor in the healthy controls. Stimulation of PBMC with PHA resulted in a marked upregulation of T-bet mRNA and protein expression for both patients and controls with no significant difference between the two groups.

CONCLUSIONS

Upregulation of T-bet may be associated with the development of a Th1 mediated immune response in VKH disease.

Protection against rat endotoxic shock by p55 tumor necrosis factor (TNF) receptor immunoadhesin: comparison with anti-TNF monoclonal antibody

The protective efficacy of a p55 tumor necrosis factor receptor immunoadhesin (TNFR-IgG) was compared with that of an anti-TNF monoclonal antibody (MAb) in a rat endotoxic shock model. TNFR-IgG (5 mg/kg), given 30 min before endotoxin (LPS), attenuated LPS induction of hypotension and tachycardia and eliminated LPS induction of serum TNF activity. In contrast, anti-TNF MAb (5 mg/kg) had little effect on LPS-induced hemodynamic changes and neutralized only partially the excessive serum TNF activity. The 6-day survival was 1 of 10 controls; 6 of 11, 5 of 7, and 8 of 9 rats receiving 0.2, 1.0, or 5.0 mg/kg TNFR-IgG, respectively; and 3 of 8 rats receiving 5 mg/kg anti-TNF MAb. These results indicate that TNFR-IgG is more potent than anti-TNF MAb at neutralizing excessive TNF activity in vivo.

Antiviral properties of a series of 1,6-naphthyridine and 7, 8-dihydroisoquinoline derivatives exhibiting potent activity against human cytomegalovirus

A series of 1,6-naphthyridine (L. Chan, H. Jin, T. Stefanac, J. F. Lavallee, G. Falardeau, W. Wang, J. Bedard, S. May, and L. Yuen, J. Med. Chem. 42:3023-3025, 1999) and isoquinoline (L. Chan, H. Jin, T. Stefanac, W. Wang, J. F. Lavallee, J. Bedard, and S. May, Bioorg. Med. Chem. Lett. 9:2583-2586, 1999) analogues exhibiting a high level of anti-human cytomegalovirus (HCMV) activity were investigated in a series of studies aimed at better understanding the mechanism of action of some representatives of this class of compounds. In vitro antiviral profiling revealed that these compounds were active against a narrow spectrum of viruses, essentially the human herpesviruses and type 2 rhinovirus. In HCMV assays, a 39- to 223-fold lower 50% inhibitory concentration was obtained for compound A1 than for ganciclovir against strains AD 169 and Towne. In addition, ganciclovir, foscarnet, cidofovir, and BDCRB (2-bromo-5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole)-resistant HCMV strains remained susceptible to 1,6-naphthyridines and 7, 8-dihydroisoquinolines tested in this study, supporting the view that a novel mechanism of action could be involved. Drug combination studies showed a small but significant synergistic antiviral effect between compound B2 and ganciclovir. Cytotoxicity profiling of representative compounds under various cell growth conditions indicated a generally similar cytotoxic effect, relative to ganciclovir, in log-phase growing cells. However, in stationary cells, a relatively higher level of toxicity was observed than that for control compound. Effect of time of drug addition showed that the anti-HCMV activity of compound A1, ganciclovir, and cidofovir was lost at approximately the same time (72 h postinfection), indicating that the compound was affecting events at the early and late stage of virus replication. This interpretation is also supported by reduction of de novo synthesis of pp65 tegument protein and lack of any effect of the compound on viral adsorption. A reduction of the HCMV enhancer-promoter-directed luciferase expression was also observed in a stably transfected cell line when compound A1 was present at relatively high concentrations.

Identification of quantitative Loci for tolerance to barley yellow dwarf virus in oat

ABSTRACT Molecular markers linked to quantitative trait loci conditioning tolerance to barley yellow dwarf virus (BYDV) were identified in oat (Avena sativa) using amplified fragment length polymorphism (AFLP) analysis. Near-isogenic and recombinant inbred lines (NILs and RILs, respectively) derived from a cross of Clintland64 (BYDV-sensitive) and IL86-5698 (BYDV-tolerant) were evaluated for their responses to an Illinois isolate of the PAV strain of BYDV. Individual markers identified in the analysis of the NILs explained up to 35% of the variability seen in the tolerance response. Single-point analysis of the marker data from the RIL population identified 24 markers in three linkage groups that were associated with tolerance to BYDV infection at P </= 0.001. These markers defined three major loci, A, C, and E, that were contributed by the tolerant parent (IL86-5698) and explained 35.0, 20.6, and 17.0% of the variability, respectively. Three minor loci G, H(1), and R) were identified at P </= 0.01. These loci were contributed by the sensitive parent (Clintland64) and explained 5.8, 5.6, and 5.6% of the variability, respectively. Interval analysis showed that only the loci A, C, and E are associated significantly with BYDV tolerance at log of the likelihood ratio >/= 3.0. These loci explained about 50% total of the variation in BYDV tolerance in multimarker regression analysis in both years. The BYDV tolerance loci A, C, E, and R were mapped to hexaploid oat restriction fragment length polymorphism linkage groups 2, 8, 36, and 5, respectively, by analyzing the segregation of the AFLP markers in the Kanota x Ogle RIL population.

Autumn southward 'return' migration of the mosquito Culex tritaeniorhynchus in China

Direct evidence for a southward 'return' migration in autumn of the mosquito Culex tritaeniorhynchus in China was obtained by aerial sampling with a net suspended from a balloon. In a preliminary study between 2 and 20 September 1990 at Jiangpu, near Nanjing, in Jiangsu Province, 11 females and 4 males of this species were taken at heights of 150-250 m. During 17-26 October 1991 at Dongxiang in northern Jiangxi Province, 44 mosquitoes (8 males, 36 females) were caught in the aerial net at heights of 80-380 m in northeasterly winds (E-NNW). Most of the specimens were flying within the subsiding air-mass behind a cold front. Cx tritaeniorhynchus was the only species identified (31 females) among the mosquitoes from Dongxiang. Of 24 females dissected, 17 had N stage ovaries--interpreted as diapause, five had stage I ovaries, one had stage II ovaries, and one was gravid (stage V), but none was freshly blood-fed. Cx tritaeniorhynchus is the main vector of Japanese viral encephalitis in China, and it is possible that the virus is reintroduced to northern temperate areas in spring by northward migration of infected Cx tritaeniorhynchus females.