A Tentative Tamdy Orthonairovirus Related to Febrile Illness in Northwestern China

BACKGROUND

Many novel tick-borne viruses have been discovered by deep-sequencing technology in recent years; however, their medical significance is unknown.

METHODS

We obtained clinical data of a patient from Xinjiang, China. Possible pathogens were detected by metagenomic analysis; the causative pathogen Tacheng tick virus 1 (TcTV-1) was found and further confirmed by reverse transcriptase-polymerase chain reaction, viral culture, and sequence analyses. Epidemiological investigation was conducted in the local human population, domestic animals, and ticks by serological/molecular methods.

RESULTS

A 62-year-old woman with a history of tick bite in Qinghe, Xinjiang, presented with fever and rashes. These symptoms were relieved after clinical treatment. TcTV-1 (strain QH1) was isolated from the patient's cerebrospinal fluid, throat swabs, and urine on day 47 after illness onset. Although the blood and urine showed viral RNA positive on day 73 after illness onset, the virus was only isolated from urine. Serological detection revealed a virus neutralizing antibody titer of 1:40 and 1:80 on day 47 and 73 after illness onset, respectively. No coinfection with other pathogens was detected, suggesting TcTV-1 may be the potential causative pathogen. We detected anti-TcTV-1 antibodies (immunoglobulin G: 10.1%; immunoglobulin M: 4.8%) in the local human population. The viral RNA was also found in cattle (4.9%), sheep (9.2%), and ticks, including Dermacentor marginatus (14.3%), Dermacentor silvarum (11.8%), Dermacentor nuttalli (6.7%), and Hyalomma asiaticum (4.8%).

CONCLUSIONS

TcTV-1 may be associated with a febrile illness syndrome, and epidemiological data of the virus in humans and animals necessitate disease surveillance of TcTV-1 infection in China.

Bond graph modelling of chemoelectrical energy transduction

Energy‐based bond graph modelling of biomolecular systems is extended to include chemoelectrical transduction thus enabling integrated thermodynamically compliant modelling of chemoelectrical systems in general and excitable membranes in particular. Our general approach is illustrated by recreating a well‐known model of an excitable membrane. This model is used to investigate the energy consumed during a membrane action potential thus contributing to the current debate on the trade‐off between the speed of an action potential event and energy consumption. The influx of Na+ is often taken as a proxy for energy consumption; in contrast, this study presents an energy‐based model of action potentials. As the energy‐based approach avoids the assumptions underlying the proxy approach it can be directly used to compute energy consumption in both healthy and diseased neurons. These results are illustrated by comparing the energy consumption of healthy and degenerative retinal ganglion cells using both simulated and in vitro data.

Synergy between seeking safety and twelve-step affiliation on substance use outcomes for women

OBJECTIVE

The Recovery Management paradigm provides a conceptual framework for the examination of joint impact of a focal treatment and post-treatment service utilization on substance abuse treatment outcomes. We test this framework by examining the interactive effects of a treatment for comorbid PTSD and substance use, Seeking Safety, and post-treatment Twelve-Step Affiliation (TSA) on alcohol and cocaine use.

METHOD

Data from 353 women in a six-site, randomized controlled effectiveness trial within the NIDA Clinical Trials Network were analyzed under latent class pattern mixture modeling. LCPMM was used to model variation in Seeking Safety by TSA interaction effects on alcohol and cocaine use.

RESULTS

Significant reductions in alcohol use among women in Seeking Safety (compared to health education) were observed; women in the Seeking Safety condition who followed up with TSA had the greatest reductions over time in alcohol use. Reductions in cocaine use over time were also observed but did not differ between treatment conditions nor were there interactions with post-treatment TSA.

CONCLUSIONS

Findings advance understanding of the complexities for treatment and continuing recovery processes for women with PTSD and SUDs, and further support the chronic disease model of addiction.

Blood pressure and levels of Fe, Ca, Mg, Zn, Cu, Na and K in the hair of young Bantu men from Tanzania

Mineral imbalance in the body may significantly contribute to the development and course of hypertension. In this paper, blood pressure figures have been linked to the levels of Fe, Ca, Mg, Zn, Cu, Na and K in hair. The research sample was composed of young men (n = 91) aged 13-21, from the town of Mafinga, Iringa District, Tanzania. The data collected included their age, tribal background and weekly diet. Based on body mass index, the participants were categorised into pre-defined subgroups. To examine how the minerals in question affect blood pressure, correlation analysis and multiple ridge regression analysis were performed. Analysis of ridge regression findings for the researched group (n = 91) shows that the minerals under scrutiny account for systolic blood pressure variation in 13 % and in 15 % for diastolic blood pressure variation. After including two additional variables-calendar age and body mass index-in regression analysis, the ultimate coefficient of determination (R (2)) changes for systolic blood pressure and remains the same for diastolic blood pressure (R (2) = 0.194 and R (2) = 0.156, respectively). Nutritional analysis shows that the students included in the study received insufficient calories per day (1,500-2,200 kcal). The group of students with abnormal blood pressure were not aware of their poor health. Research findings may result from progressive environmental changes and poor nutrition in terms of food quantity and quality, which had an impact on the subjects' blood pressure. Hair analysis used to determine mineral content in the body may be an auxiliary tool in identifying the links between factors leading to the development of hypertension.

Evidence for a potential tumor suppressor role for the Na,K-ATPase beta1-subunit

The Na,K-ATPase, consisting of two essential subunits (alpha, beta), plays a critical role in the regulation of ion homeostasis in mammalian cells. Recent studies indicate that reduced expression of the beta1 isoform (NaK-beta1) is commonly observed in carcinoma and is associated with events involved in cancer progression. In this study, we present evidence that repletion of NaK-beta1 in Moloney sarcoma virus-transformed Madin-Darby canine kidney cells (MSV-MDCK), a highly tumorigenic cell line, inhibits anchorage independent growth and suppresses tumor formation in immunocompromised mice. Additionally, using an in vitro cell-cell aggregation assay, we showed that cell aggregates of NaK-beta1 subunit expressing MSV-MDCK cells have reduced extracellular regulated kinase (ERK) 1/2 activity compared with parental MSV-MDCK cells. Finally, using immunohistochemistry and fully quantitative image analysis approaches, we showed that the levels of phosphorylated ERK 1/2 are inversely correlated to the NaK-beta1 levels in the tumors. These findings reveal for the first time that NaK-beta1 has a potential tumor-suppressor function in epithelial cells.

Dopamine receptor modulation of hypoxic-ischemic neuronal injury in striatum of newborn piglets

Dopamine receptors regulate glutamatergic neurotransmission and Na(+),K(+)-ATPase via protein kinase A (PKA) and dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32)-dependent signaling. Consequently, dopamine receptor activation may modulate neonatal hypoxic-ischemic (H-I) neuronal damage in the selectively vulnerable putamen enriched with dopaminergic receptors. Piglets subjected to two durations of hypoxia followed by asphyxic cardiac arrest were treated with a D1-like (SCH23390) or D2-like (sulpiride) receptor antagonist. At 4 days of recovery from less severe H-I, the remaining viable neurons in putamen were 60% of control, but nearly completely salvaged by pretreatment with SCH23390 or sulpiride. After more severe H-I in which only 18% of neurons were viable, partial neuroprotection was seen with SCH23390 pretreatment (50%) and posttreatment (39%) and with sulpiride pretreatment (35%), but not with sulpiride posttreatment (24%). Dopamine was significantly elevated in microdialysis samples from putamen during asphyxia and the first 15 mins of reoxygenation. Pretreatment with SCH23390 or sulpiride largely attenuated the increased nitrotyrosine and the decreased Na(+),K(+)-ATPase activity that occurred at 3 h after severe H-I. Pretreatment with SCH23390, but not sulpiride, also attenuated H-I-induced increases in PKA-dependent phosphorylation of Thr34 on DARPP-32, Ser943 on the alpha subunit of Na(+),K(+)-ATPase, and Ser897 of the N-methyl-D-aspartate (NMDA) receptor NR1 subunit. These findings indicate that D1 and D2 dopamine receptor activation contribute to neuronal death in newborn putamen after H-I in association with increased protein nitration and decreased Na(+),K(+)-ATPase activity. Furthermore, mechanisms of D1 receptor toxicity may involve DARPP-32-dependent phosphorylation of NMDA receptor NR1 and Na(+),K(+)-ATPase.

Role of homologous ASP334 and GLU319 in human non-gastric H,K- and Na,K-ATPases in cardiac glycoside binding

Cardiac steroids inhibit Na,K-ATPase and the related non-gastric H,K-ATPase, while they do not interact with gastric H,K-ATPase. Introducing an arginine, the residue present in the gastric H,K-ATPase, in the second extracellular loop at the corresponding position 334 in the human non-gastric H,K-ATPase (D334R mutation) rendered it completely resistant to 2mM ouabain. The corresponding mutation (E319R) in alpha1 Na,K-ATPase produced a approximately 2-fold increase of the ouabain IC(50) in the ouabain-resistant rat alpha1 Na,K-ATPase and a large decrease of the ouabain affinity of human alpha1 Na,K-ATPase, on the other hand this mutation had no effect on the affinity for the aglycone ouabagenin. These results provide a strong support for the orientation of ouabain in its biding site with its sugar moiety interacting directly with the second extracellular loop.

CRYM mutations cause deafness through thyroid hormone binding properties in the fibrocytes of the cochlea

BACKGROUND

In a search for mutations of mu-crystallin (CRYM), a taxion specific crystalline which is also known as an NADP regulated thyroid hormone binding protein, two mutations were found at the C-terminus in patients with non-syndromic deafness.

OBJECTIVE

To investigate the mechanism of hearing loss caused by CRYM mutations

METHODS

T3 binding activity of mutant mu-crystallin was compared with that of wild-type mu-crystallin, because mu-crystallin is known to be identical to T3 binding protein. To explore the sites within the cochlea where mu-crystallin is functioning, its localisation in the mouse cochlea was investigated immunocytochemically using a specific antibody.

RESULTS

One mutant was shown to have no binding capacity for T3, indicating that CRYM mutations cause auditory dysfunction through thyroid hormone binding properties. Immunocytochemical results indicated that mu-crystallin was distributed within type II fibrocytes of the lateral wall, which are known to contain Na,K-ATPase.

CONCLUSIONS

CRYM mutations may cause auditory dysfunction through thyroid hormone binding effects on the fibrocytes of the cochlea. mu-Crystallin may be involved in the potassium ion recycling system together with Na,K-ATPase. Future animal experiments will be necessary to confirm a causal relation between Na,K-ATPase, T3, and deafness.

Phenelzine treatment increases transcription factor AP-2 levels in rat brain

BACKGROUND

The elevations of noradrenaline (NA) and serotonin (5-HT) levels in response to acute serotonin reuptake inhibitor (SSRI) or tricyclic antidepressant (TCA) exposure are not consistent with the time course for the therapeutic action of these antidepressants. Thus, neuronal adaptations are needed for the therapeutic effect to arise. Transcription factor Activating Protein -2 (AP-2) is critical for mammalian neural gene expression. Several genes involved in brainstem CNS transmitter systems, especially the monoamines, have AP-2 binding sites in their regulatory regions. We have previously shown that treatment with citalopram and imipramin resulted in a decrease in AP-2alpha and AP-2beta levels in rat brain. We have also reported an association between a specific genotype of AP-2beta to personality traits, binge-eating disorder and platelet monoamine oxidase (MAO) activity.

RESULTS

Subchronic administration (10 days) of phenelzine (PLZ) increased the levels of AP-2alpha, AP-2beta and the DNA binding activity of AP-2 in nuclear extracts prepared from rat whole brain when compared with sham treated animals.

CONCLUSION

These data suggest that AP-2 is not involved in the therapeutic effect of antidepressants. Rather, the effects of antidepressants seen on the levels of AP-2 might be involved in the expression of side-effects during the lag-period.

Epithelial Na, K-ATPase expression is down-regulated in canine prostate cancer; a possible consequence of metabolic transformation in the process of prostate malignancy

BACKGROUND: An important physiological function of the normal prostate gland is the synthesis and secretion of a citrate rich prostatic fluid. In prostate cancer, citrate production levels are reduced as a result of altered cellular metabolism and bioenergetics. Na, K-ATPase is essential for citrate production since the inward Na+ gradients it generates are utilized for the Na+ dependent uptake of aspartate, a major substrate for citrate synthesis. The objective of this study was to compare the expression of previously identified Na, K-ATPase isoforms in normal canine prostate, benign prostatic hyperplasia (BPH) and prostatic adenocarcinoma (PCa) using immunohistochemistry in order to determine whether reduced citrate levels in PCa are also accompanied by changes in Na, K-ATPase expression. RESULTS: Expression of Na, K-ATPase alpha1 and beta1 isoforms was observed in the lateral and basolateral plasma membrane domains of prostatic epithelial cells in normal and BPH prostates. Canine kidney was used as positive control for expression of Na, K-ATPase alpha1 and gamma isoforms. The alpha1 isoform was detected in abundance in prostatic epithelial cells but there was no evidence of alpha2, alpha3 or gamma subunit expression. In advanced PCa, Na, K-ATPase alpha1 isoform expression was significantly lower compared to normal and BPH glands. The abundant basolateral immunostaining observed in normal and BPH tissue was significantly attenuated in PCa. CONCLUSION: The loss of epithelial structure and function and the transformation of normal epithelial cells to malignant cells in the canine prostate have important implications for cellular metabolism and are accompanied by a down regulation of Na, K-ATPase.

Frequency dependence of muscarinic facilitation of transmitter release in urinary bladder strips from neurally intact or chronic spinal cord transected rats

1. Electrical stimulation evoked release of 3H-noradrenaline (NA) and 14C-acetylcholine (ACh), as well as neurally evoked contractions were measured at various (1-40 Hz, 100 shocks) stimulation frequencies in bladder strips from neurally intact (NI) and spinal cord transected (SCT) rats. 2. The frequency response curves for ACh and NA release were shifted to the left in SCT bladder strips as compared to NI bladder strips. 3. Atropine (1 microM) depressed ACh release in NI bladder strips at high frequency stimulation (10 and 40 Hz) but not at low frequency stimulation (2-5 Hz). However, in SCT bladders, atropine depressed ACh release both at low and high frequencies of stimulation, indicating that muscarinic facilitation occurs at lower frequencies. 4. Atropine depressed the release of NA in NI bladders at only 40 Hz stimulation, but depressed release at all frequencies in SCT bladders. 5. The amplitude of neurally evoked contractions of bladder strips from NI rats was enhanced as the frequency of stimulation was increased from 1 to 40 Hz (80 shocks). The frequency response curve was shifted to the left in SCT bladders. Atropine blocked the neurally evoked contractions in SCT bladder strips to a greater extent than the contractions in NI strips indicating a cholinergic dominance in the SCT bladders. 6. Maximal contractile force of SCT bladder strips evoked by neural stimulation at 20 Hz 10 shocks and 80 shocks was significantly lower than that of NI bladder strips, whereas the release of ACh was significantly higher in SCT than NI bladders indicating a postjunctional defect in the SCT preparations. 7. It is suggested that presynaptic muscarinic facilitatory mechanisms are upregulated in the cholinergic and adrenergic nerve terminals in SCT bladders leading to a larger relative contractile response at lower frequencies of stimulation (2-5 Hz). Thus the hyperreflexic bladder occurring after spinal cord injury may be due in part to an enhancement of transmitter release at bladder postganglionic nerve terminals.

Fe-catalyzed cleavage of the alpha subunit of Na/K-ATPase: evidence for conformation-sensitive interactions between cytoplasmic domains

Incubation of Na/K-ATPase with ascorbate plus H2O2 produces specific cleavage of the alpha subunit. Five fragments with intact C termini and complementary fragments with intact N termini were observed. The beta subunit is not cleaved. Cleavages depend on the presence of contaminant or added Fe2+ ions, as inferred by suppression of cleavages with nonspecific metal complexants (histidine, EDTA, phenanthroline) or the Fe3+-specific complexant desferrioxamine, or acceleration of cleavages by addition of low concentrations of Fe2+ but not of other heavy metal ions. Na/K-ATPase is inactivated in addition to cleavage, and both effects are insensitive to OH. radical scavengers. Cleavages are sensitive to conformation. In low ionic strength media (E2) or media containing Rb ions [E2(Rb)], cleavage is much faster than in high ionic strength media (E1) or media containing Na ions (E1Na). N-terminal fragments and two C-terminal fragments (N-terminals E214 and V712) have been identified by amino acid sequencing. Approximate positions of other cleavages were determined with specific antibodies. The results suggest that Fe2+ (or Fe3+) ions bind with high affinity at the cytoplasmic surface and catalyze cleavages of peptide bonds close to the Fe2+ (or Fe3+) ion. Thus, cleavage patterns can provide information on spatial organization of the polypeptide chain. We propose that highly conserved regions of the alpha subunit, within the minor and major cytoplasmic loops, interact in the E2 or E2(Rb) conformations but move apart in the E1 or E1Na conformations. We discuss implications of domain interactions for the energy transduction mechanism. Fe-catalyzed cleavages may be applicable to other P-type pumps or membrane proteins.

Equilibrium of phosphointermediates of sodium and potassium ion transport adenosine triphosphatase: action of sodium ion and Hofmeister effect

Sodium and potassium ion transport adenosine triphosphatase accepts and donates a phosphate group in the course of its reaction sequence. The phosphorylated enzyme has two principal reactive states, E1P and E2P. E1P is formed reversibly from ATP in the presence of Na+ and is precursor to E2P, which equilibrates with P(i) in the presence of K+. We studied equilibrium between these states at 4 degrees C and the effect of Na+ on it. To optimize the reaction system we used a Hofmeister effect, replacing the usual anion, chloride, with a chaotropic anion, usually nitrate. We phosphorylated enzyme from canine kidney with [32P]ATP. We estimated interconversion rate constants for the reaction E1P <--> E2P and their ratio. To estimate rate constants we terminated phosphorylation and observed decay kinetics. We observed E1P or E2P selectively by adding K+ or ADP respectively. K+ dephosphorylates E2P leaving E1P as observable species; ADP dephosphorylates E1P leaving E2P as observable species. We fitted a 2-pool model comprising two reactive species or a twin 2-pool model, comprising a pair of independent 2-pool models, to the data and obtained interconversion and hydrolysis rate constants for each state. Replacing Na+ with Tris+ or lysine+ did not change the ratio of interconversion rate constants between E1P and E2P. Thus Na+ binds about equally strongly to E1P and E2P. This conclusion is consistent with a model of Pedemonte (1988. J. Theor. Biol. 134:165-182.). We found that Na+ affected another equilibrium, that of transphosphorylation between ATP x dephosphoenzyme and ADP x E1P. We used the reactions and model of Pickart and Jencks (1982. J. Biol. Chem. 257:5319-5322.) to generate and fit data. Decreasing the concentration of Na+ 10-fold shifted the equilibrium constant 10-fold favoring ADP x E1P over ATP x dephosphoenzyme. Thus Na+ can dissociate from E1P x Na3. Furthermore, we found two characteristics of Hofmeister effects on this enzyme.