[Immediate postoperative color Doppler ultrasonography on the diagnosis of hemorrhagic complications of liver biopsy and its directed compression hemostasis]

Objective: To study the diagnostic value of immediate color Doppler ultrasonography on traumatic hepatic hemorrhage after tissue sampling with ultrasound-guided liver biopsy and the clinical effect of its-directed local compression hemostasis at puncture-site. Methods: 132 hospitalized patients with various liver diseases underwent ultrasound-guided hepatic puncture-biopsies, including 61 cases with diffuse parenchymal and 71 cases with focal liver lesions. Immediate postoperative color Doppler ultrasonography was performed following liver biopsy. Abnormal blood flow signal was observed at hepatic puncture biopsy site, and if there were hemorrhagic signals, ultrasound-directed local compression hemostasis was performed until the bleeding signal disappeared. F-test and Chi-square test were used for statistical analysis. Results: Immediate color Doppler ultrasonography showed traumatic hemorrhage in 36.1% (22/61) and 40.8% (29/71) cases of diffuse liver disease and focal liver disease group, respectively. All hemorrhagic signals were eventually disappeared after ultrasound-directed local compression hemostasis. The median hemostasis time was 2 min in both groups, and there was no statistically significant difference in bleeding rate and hemostasis time between the two groups (P>0.05). There were no serious complications and deaths. Conclusion: Traumatic hepatic hemorrhage along the needle puncture tract is a common accompanying condition during liver biopsy. Immediate postoperative color Doppler ultrasonography can trace bleeding signals in timely manner and direct effective compression hemostasis, so it should be used routinely to help avoid occurrence of severe hemorrhagic complications.

Electrochemically active biofilm-assisted biogenic synthesis of an Ag-decorated ZnO@C core–shell ternary plasmonic photocatalyst with enhanced visible-photocatalytic activity

An Ag–ZnO@C core–shell ternary photocatalyst was synthesized via a bio-catalytic route for photocatalytic degradation of RhB and 4-NP under visible light.

Influence of various levels of milk by-products in weaner diets on growth performance, blood urea nitrogen, diarrhea incidence, and pork quality of weaning to finishing pigs

OBJECTIVE

This study was conducted to evaluate various levels of milk by-product in weaning pig diet on growth performance, blood profiles, carcass characteristics and economic performance for weaning to finishing pigs.

METHODS

A total of 160 weaning pigs ([Yorkshire×Landrace]×Duroc), average 7.01±1.32 kg body weight (BW), were allotted to four treatments by BW and sex in 10 replications with 4 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with various levels of milk by-product (Phase 1: 0%, 10%, 20%, and 30%, Phase 2: 0%, 5%, 10%, and 15%, respectively). During weaning period (0 to 5 week), weaning pigs were fed experimental diets and all pigs were fed the same commercial feed during growing-finishing period (6 to 14 week).

RESULTS

In the growth trial, BW, average daily gain (ADG), and average daily feed intake (ADFI) in the nursery period (5 weeks) increased as the milk by-product level in the diet increased (linear, p<0.05). Linear increases of pig BW with increasing the milk product levels were observed until late growing period (linear, p = 0.01). However, there were no significant differences in BW at the finishing periods, ADG, ADFI, and gain:feed ratio during the entire growing-finishing periods. The blood urea nitrogen concentration had no significant difference among dietary treatments. High inclusion level of milk by-product in weaner diet decreased crude protein (quadratic, p = 0.05) and crude ash (Linear, p = 0.05) of Longissimus muscle. In addition, cooking loss and water holding capacity increased with increasing milk product levels in the weaner diets (linear, p<0.01; p = 0.05). High milk by-product treatment had higher feed cost per weight gain compared to non-milk by-products treatment (linear, p = 0.01).

CONCLUSION

Supplementation of 10% to 5% milk by-products in weaning pig diet had results equivalent to the 30% to 15% milk treatment and 0% milk by-product supplementation in the diet had no negative influence on growth performance of finishing pigs.

Metal-Free Carbon-Based Materials: Promising Electrocatalysts for Oxygen Reduction Reaction in Microbial Fuel Cells

Microbial fuel cells (MFCs) are a promising green approach for wastewater treatment with the simultaneous advantage of energy production. Among the various limiting factors, the cathodic limitation, with respect to performance and cost, is one of the main obstacles to the practical applications of MFCs. Despite the high performance of platinum and other metal-based cathodes, their practical use is limited by their high cost, low stability, and environmental toxicity. Oxygen is the most favorable electron acceptor in the case of MFCs, which reduces to water through a complicated oxygen reduction reaction (ORR). Carbon-based ORR catalysts possessing high surface area and good electrical conductivity improve the ORR kinetics by lowering the cathodic overpotential. Recently, a range of carbon-based materials have attracted attention for their exceptional ORR catalytic activity and high stability. Doping the carbon texture with a heteroatom improved their ORR activity remarkably through the favorable adsorption of oxygen and weaker molecular bonding. This review provides better insight into ORR catalysis for MFCs and the properties, performance, and applicability of various metal-free carbon-based electrocatalysts in MFCs to find the most appropriate cathodic catalyst for the practical applications. The approaches for improvement, key challenges, and future opportunities in this field are also explored.

Electrochemically synthesized sulfur-doped graphene as a superior metal-free cathodic catalyst for oxygen reduction reaction in microbial fuel cells

Electrochemically synthesized S-GN was proved to be an efficient alternative cathode catalyst to Pt/C in microbial fuel cell.

Three-dimensional, highly porous N-doped carbon foam as microorganism propitious, efficient anode for high performance microbial fuel cell

Microbial fuel cell based on as-prepared N-doped carbon foam produced 2 times higher power density than the commercial graphite felt.

Fibrous polyaniline@manganese oxide nanocomposites as supercapacitor electrode materials and cathode catalysts for improved power production in microbial fuel cells

Fibrous Pani–MnO₂ nanocomposites were prepared using a one-step and scalable in situ chemical oxidative polymerization method.

Positively charged gold nanoparticles synthesized by electrochemically active biofilm--a biogenic approach

Positively charged gold nanoparticles [(+) AuNPs] of 5-20 nm were synthesized by using electrochemically active biofilm (EAB) formed on a stainless steel mesh, within 30 minutes, in aqueous solution containing HAuCl4 as a precursor and sodium acetate as an electron donor. Electrochemically active bacteria present on biofilm oxidize the sodium acetate by producing electrons. Simultaneously, stainless steel also provides electrons because of the Cl- ions penetration into the stainless steel. Combined effect of both the EAB and stainless steel mesh enhances the availability of electrons for the reduction of Au3+ in the solution, which makes this synthesis efficient and fast. Therefore, small size, positively charged (+32.72 mV), monodispersed, controlled, easy separation and extracellular synthesis of (+) AuNPs makes this protocol highly significant. As-synthesized AuNPs were characterized by UV-vis, DLS, XRD, TEM, HRTEM, EDX and SAED. (+) AuNPs shows remarkable enhancement in the rate of reduction of methyl orange by NaBH4 because of the electron relay effect.

Synthesis of positively charged gold nanoparticles using a stainless-steel mesh

A novel, rapid, one-pot, and facile approach was developed to synthesize positively charged gold nanoparticles [(+) AuNPs] by employing an aqueous solution of HAuCl4 x 3H2O as a precursor at 30 degrees C and a stainless-steel mesh as a reducing agent. The penetration of Cl- ions into the stainless-steel surface results in corrosion on the stainless-steel surface and excretion of electrons which are used for reduction of Au3+ --> Au0. As a result, (+) AuNPs 5-20 nm in size, mostly monodispersed, were synthesized within 3 h. The as-synthesized AuNPs were charaterized by UV-vis, DLS, XRD, TEM, HR-TEM, EDX and SAED. The utilization of non-toxic chemicals and easily available materials, and the non-requirement of energy input, make this methodology easy, inexpensive, and efficient. The new findings about the role of the stainless-steel mesh, which provides electrons in the presence of Cl- ions, for the reduction of Au3+ --> Au0, makes it a novel material for (+) AuNPs synthesis.

Environmental factors affecting indole production in Escherichia coli

A variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole as an intercellular signal in microbial communities. Biosynthesis of indole is well-studied, and while carbon sources and amino acids are important environmental cues for indole production in Escherichia coli, other environmental factors affecting indole production for this strain are less clear. This study demonstrates that the environmental cue pH is an important factor for indole production that further controls biofilm formation of E. coli. Moreover, E. coli produced a higher level of extracellular indole in the presence of the antibiotics ampicillin and kanamycin, and the increased indole enhanced cell survival during antibiotic stress. Additionally, we found here that temperature is another important factor for indole production; E. coli produces and accumulates a large amount of indole at 50 °C, even at low cell densities. Overall, our results suggest that indole is a stable biological compound, and E. coli may utilize indole to protect itself against other microorganisms.

Vector prime protein boost vaccination in the setting of myeloablative-induced lymphopenia suppresses growth of leukemia and solid tumors

We have developed a vaccine, which is designed to induce tumor-associated antigen (TAA)-specific T cells and antibodies in the setting of profound lymphopenia induced by myeloablative therapy and T-cell-depleted bone marrow transplantation. Test mice were injected subcutaneously (sc) with the 32DP210Bcr-Abl cell line, which is positive for the p210Bcr-Abl protein (Group 1). In Group 2, 7 days after injection of the 32DP210Bcr-Abl positive cell line, the mice received 900 cGy total body irradiation (TBI) followed in 1 h by the intravenous infusion of 10 million T-cell-depleted syngeneic bone marrow cells (TCDBMT) (Group 2). The leukemia-bearing group received an intravenous injection of 10 million spleen cells (donor lymphocyte infusions) from unvaccinated (Group 3) and TAA/ecdCD40L-vaccinated (Group 4) syngeneic mice 3 days after completion of the TBI and TCDBMT. Groups 3 and 4 mice received three additional sc vaccinations at 7-day intervals with the TAA/ecdCD40L vaccine, in which the TAA was taken from the junctional peptide of the P210bcr-Abl protein. The survival of Groups 3 and 4 mice was significantly longer than that in Groups 1 and 2 mice. Vaccinated mice from Group 4, which developed complete responses, survived up to 350 days post-injection of the leukemia cells without any evidence of leukemia regrowth.

Decomposition of 1,4-dioxane by photo-Fenton oxidation coupled with activated sludge in a polyester manufacturing process

The cyclic ether 1,4-dioxane is a synthetic industrial chemical that is used as a solvent in producing paints and lacquers. The EPA and the International Agency for Research on Cancer(IARC) classified 1,4-dioxane as a GROUP B2(probable human) carcinogen. 1,4-dioxane is also produced as a by-product during the manufacture of polyester. In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, Korea was investigated regarding the release of high concentrations of 1,4-dioxane (about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2010). A 10 ton/day pilot-scale treatment system using photo-Fenton oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2800 ppm H(2)O(2) and 1,400 ppm FeSO(4) were maintained along with 10 UV-C lamps (240 microW/cm(2)) installed and operated continuously during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L where TOC concentration in the effluent had been moreover increased due to decomposed products such as aldehydes and organic acids. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane and their by-products (i.e., TOC). As a result, 1,4-dioxane in the effluent has been decreased as low as 0.5 mg/L. The optimal conditions for the activated sludge process that were obtained are as follows: DO, 3-3.5 mg/L; HRT, 24 h; SRT 15 d; MLSS, 3,000 mg/L. Consequently, photo-Fenton oxidation coupled with activated sludge can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.

Molecular characterization of T-type Ca(2+) channels responsible for low threshold spikes in hypothalamic paraventricular nucleus neurons

The hypothalamic paraventricular nucleus (PVN) is composed of functionally heterogeneous cell groups, possessing distinct electrophysiological properties depending on their functional roles. Previously, T-type Ca(2+) dependent low-threshold spikes (LTS) have been demonstrated in various PVN neuronal types, including preautonomic cells. However, the molecular composition and functional properties of the underlying T-type Ca(2+) channels have not been characterized. In the present study, we combined single cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry and patch-clamp recordings to identify subtypes of T-type Ca(2+) channels expressed in PVN cells displaying LTS (PVN-LTS), including identified preautonomic neurons. LTS appeared at the end of hyperpolarizing pulses either as long-lasting plateaus or as short-lasting depolarizing humps. LTS were mediated by rapidly activating and inactivating T-type Ca(2+) currents and were blocked by Ni(2+). Single cell RT-PCR and immunohistochemical studies revealed Cav3.1 (voltage-gated Ca(2+) channel) as the main channel subunit detected in PVN-LTS neurons. In conclusion, these data indicate that Cav3.1 is the major subtype of T-type Ca(2+) channel subunit that mediates T-type Ca(2+) dependent LTS in PVN neurons.

The neck crease as a landmark of Chassaignac's tubercle in stellate ganglion block: anatomical and radiological evaluation

BACKGROUND

Stellate ganglion block (SGB) is most commonly performed at the transverse process of the sixth cervical vertebra, the identification of which could be difficult in patients with short and wide necks. This study was conducted to evaluate whether the neck skin crease is a reliable indicator of the C6 level.

METHODS

Forty-nine relatively obese pain clinic patients were investigated. They assumed a standard position for SGB. A radiopaque wire was placed along the neck skin crease caudad to the thyroid cartilage. Next, a radiopaque indicator was placed on the skin above the tubercle found to be most prominent by palpation. X-rays of the neck were obtained after each procedure.

RESULTS

The probability that the neck crease would cross C5, C6 and C7 was 16%, 71%, and 12%, respectively. The most prominent tubercle corresponded to the C5, C6 and C7 levels in 16%, 69% and l4% of cases, respectively.

CONCLUSION

The studied means to identify the C6 transverse process was found to correlate well with each other (P<0.001). Since in 30% of cases the C6 process could not be identified by any of the studied means, radiological guidance is recommended in order to ensure optimal safety and efficacy of SGB in selected cases.

The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases

PURPOSE

To report on the use of the laryngeal mask airway (LMA) for elective Cesarean section in 1067 consecutive ASA I-II patients preferring general anesthesia.

METHODS

Patients were excluded if they had pharyngeal reflux, a pre-pregnancy body mass index >30, or had a known/predicted difficult airway. Patients were fasted for six hours and given ranitidine/sodium citrate. A rapid sequence induction was performed with thiopentone and suxamethonium. The LMA was inserted by experienced users. Anesthesia was maintained with N(2)O and 50% O(2) and a volatile agent. Cricoid pressure was maintained until delivery, but was relaxed if insertion/ventilation was difficult. Patients were intubated if an effective airway was not obtained within 90 sec, or SpO(2) <94%, or end-tidal CO(2) >45 mmHg. Postdelivery, vecuronium and fentanyl were administered.

RESULTS

An effective airway was obtained in 1060 (99%) patients, 1051 (98%) at the first attempt and nine (1%) at the second or third attempt. Air leakage or partial airway obstruction occurred in 22 (21%) patients, and seven (0.7%) patients required intubation. There were no episodes of hypoxia (SpO(2) <90%), aspiration, regurgitation, laryngospasm, bronchospasm or gastric insufflation. Surgical conditions were satisfactory and all APGAR scores were >/=7 after five minutes.

CONCLUSION

We conclude that the LMA is effective and probably safe for elective Cesarean section in healthy, selected patients when managed by experienced LMA users.

Modulation of nitric oxide bioavailability by erythrocytes

Nitric oxide (NO) activates soluble guanylyl cyclase in smooth muscle cells to induce vasodilation in the vasculature. However, as hemoglobin (Hb) is an effective scavenger of NO and is present in high concentrations inside the red blood cell (RBC), the bioavailability of NO would be too low to elicit soluble guanylyl cyclase activation in the presence of blood. Therefore, NO bioactivity must be preserved. Here we present evidence suggesting that the RBC participates in the preservation of NO bioactivity by reducing NO influx. The NO uptake by RBCs was increased and decreased by altering the degree of band 3 binding to the cytoskeleton. Methemoglobin and denatured hemoglobin binding to the RBC membrane or cytoskeleton also were shown to contribute to reducing the NO uptake rate of the RBC. These alterations in NO uptake by the RBC, hence the NO bioavailability, were determined to correlate with the vasodilation of isolated blood vessels. Our observations suggest that RBC membrane and cytoskeleton associated NO-inert proteins provide a barrier for NO diffusion and thus account for the reduction in the NO uptake rate of RBCs.

14-3-3tau associates with and activates the MEF2D transcription factor during muscle cell differentiation

Myocyte enhancer binding factor 2 (MEF2) proteins belong to the MADS box family of transcription factors and four MEF2 proteins, MEF2A, MEF2B, MEF2C and MEF2D, have been found. MEF2 proteins have been shown to play critical roles in differentiation of muscles and neuronal tissues. How transactivational activity of MEF2 proteins is regulated is not fully understood. MEF2 proteins are activated by several kinases, including Erk5 and calcium/calmodulin-dependent kinase, and interact with repressors, including histone deacetylases 4 and 5 (HDAC4 and HDAC5) and Cabin1. During the effort to understand regulation of MEF2 activity, we identified 14-3-3tau as a MEF2D-interacting molecule by yeast two-hybrid screening. We found that 14-3-3tau forms a complex with MEF2D in vivo and specifically enhances MEF2 transactivational activity. The results from transient transfection and co-precipitation experiments suggest that 14-3-3tau activates MEF2D by competitively inhibiting HDAC4 from binding to MEF2D and thereby affects muscle cell differentiation.

Prevention of postoperative nausea and vomiting by continuous infusion of subhypnotic propofol in female patients receiving intravenous patient-controlled analgesia

In this prospective, randomized, double-blind, placebo-controlled study, the use of continuous subhypnotic propofol infusion as an antiemetic in fentanyl intravenous patient-controlled analgesia (i.v. PCA) was investigated during the first 24 h after surgery. One hundred female patients, ASA I-II, aged 20-71 yr, undergoing major gynaecological or orthopaedic surgery, were included. Either propofol 10 mg or placebo (1 ml of Intralipid) was given and one of the following five regimens was maintained for 24 h: propofol 5, 10, 15 or 20 microg kg(-1) min(-1) or Intralipid 1 ml h(-1) as a placebo. Fentanyl i.v. PCA was started in the postanaesthesia care unit for postoperative analgesia. Significantly more of the patients given propofol 15 and 20 microg kg(-1) min(-1) experienced no nausea or vomiting compared with those given placebo (65% and 70% versus 25%; P<0.05). Patients given propofol 20 microg kg(-1) min(-1) reported more sedation than those in the other groups 4 h after surgery (P<0.05).

Neutralization epitopes on the antigenic domain II of the Orientia tsutsugamushi 56-kDa protein revealed by monoclonal antibodies

Monoclonal antibodies (MoAbs) reactive with the authentic Orientia tsutsugamushi 56-kDa protein were generated. MoAb FS10 and FS15 showed in vitro, as well as, in vivo neutralizing activity upon O. tsutsugamushi infection. Deletion mutants of the gene for 56-kDa protein of O. tsutsugamushi Boryong were expressed to map the binding region. FS10 and FS15 are bound to amino acids (aa) located in an antigenic domain II, at residues 140-160 and 187-214, respectively. Computer modeling indicated that aa 146-153 were important for antigenicity against FS10. A sequence for aa 142-150 was highly homologous between oriential strains. These results suggest that the antigenic determinant for neutralizing MoAbs is an epitope within aa 140-160. Furthermore, this region may be important for the adhesion/invasion or intracellular survival of O. tsutsugamushi within host cells.

Genetic diversity of Chilean and Brazilian alstroemeria species assessed by AFLP analysis

One to three accessions of 22 Alstroemeria species, an interspecific hybrid (A. aurea x A. inodora), and single accessions of Bomarea salsilla and Leontochir ovallei were evaluated using the AFLP-marker technique to estimate the genetic diversity within the genus Alstroemeria. Three primer combinations generated 716 markers and discriminated all Alstroemeria species. The dendrogram inferred from the AFLP fingerprints supported the conjecture of the generic separation of the Chilean and Brazilian Alstroemeria species. The principal co-ordinate plot showed the separate allocation of the A. ligtu group and the allocation of A. aurea, which has a wide range of geographical distribution and genetic variation, in the middle of other Alstroemeria species. The genetic distances, based on AFLP markers, determined the genomic contribution of the parents to the interspecific hybrid.

Cellular invasion of Orientia tsutsugamushi requires initial interaction with cell surface heparan sulfate

Role of transmembrane heparan sulfate proteoglycans on invasion of Orientia tsutsugamushi into host cells was investigated. Pretreatment with heparan sulfate and heparin inhibited the infection of O. tsutsugamushi for L cell, mouse fibroblast, whereas other glycosaminoglycans had little effect. These same treatments were also shown to reduce the infection in a dose-dependent manner, and enzymatic treatment of cells with heparitinase, but not chondroitinase ABC, inhibited the infection. In addition, mutant cell lines of Chinese hamster ovarian cell defective in heparan sulfate synthesis but not chondrotin sulfate synthesis and defective in all glycosaminoglycan synthesis showed marked reduction in susceptibility to infection by O. tsutsugamushi. Also mutant cell lines, which express heparan sulfate proteoglycans at low level, showed intermediate level of infectivity. Finally O. tsutsugamushi bind to(35)S-labelled heparin. Collectively, these findings provide strong evidence that heparan sulfate proteoglycans contribute to the attachment of O. tsutsugamushi to the cells.

Sp1 mediates constitutive and transforming growth factor beta-inducible expression of urokinase type plasminogen activator receptor gene in human monocyte-like U937 cells

Urokinase type plasminogen activator receptor (uPAR) is known to be involved in conversion of plasminogen into plasmin and its expression can be regulated by a variety of biological agents including transforming growth factor beta (TGF-beta). In the present study, we cloned the promoter region of the human uPAR (huPAR) gene (-653 to +61) and investigated the transcription regulatory mechanism of the expression of the huPAR gene upon treatment with TGF-beta in human monocyte-like U937 cells. By deletion and point mutational analysis of the huPAR gene promoter, it was found that the sequence positioned at -70 is required for both constitutive and TGF-beta-inducible expression of the huPAR gene in U937 cells. Using electrophoretic mobility shift assay, we could observe that Sp1 formed a DNA-protein complex at the -70 sequence. In addition, antisense oligonucleotide against human Sp1 blocked both constitutive and TGF-beta-inducible expression of the luciferase reporter gene driven by the huPAR gene promoter in U937 cells. These results led us to conclude that Sp1 transcription factor mediates constitutive and TGF-beta-inducible expression of the huPAR gene in U937 cells through binding to the sequence located at -70.

Expression of chemokine genes in murine macrophages infected with Orientia tsutsugamushi

Scrub typhus, caused by Orientia tsutsugamushi infection, is characterized by local as well as systemic inflammatory manifestations. Inflammation is initiated by O. tsutsugamushi-infected macrophages and endothelial cells in the dermis. We investigated the regulation of chemokine induction in macrophage cell line J774A.1 in response to O. tsutsugamushi infection. The mRNAs for macrophage inflammatory proteins 1alpha/beta (MIP-1alpha/beta), MIP-2, and macrophage chemoattractant protein 1 were induced within 30 min, and their levels showed a transitory peak for 3 to 12 h. However, the lymphotactin, eotaxin, gamma interferon-inducible protein 10, and T-cell activation gene 3 mRNAs were not detected by RNase protection assays. Heat-killed O. tsutsugamushi induced a similar extent of chemokine responses. Induction of the chemokine genes was not blocked by the eukaryotic protein synthesis inhibitor cycloheximide, suggesting that de novo synthesis of host cell protein is not required for these transcriptional responses. The induction of chemokine mRNAs by O. tsutsugamushi was blocked by the inhibitors of NF-kappaB activation. Furthermore, O. tsutsugamushi induced the nuclear translocation and activation of NF-kappaB. These results demonstrate that heat-stable molecules of O. tsutsugamushi induce a subset of chemokine genes and that induction involves activation of the transcription factor NF-kappaB.

Requirement of MEF2D in the induced differentiation of HL60 promyeloid cells

The regulatory role of MEF2 (myocyte enhancer binding factor 2) proteins in nonmuscle tissues has not been well characterized. We examined the expression of MEF2 family members, namely, MEF2A, -B, -C, and -D, in the differentiation of HL60 promyeloid cells and observed the remarkable increase in the expressions of MEF2A and MEF2D proteins during the differentiation process into monocytes. To examine the role of MEF2, we expressed a dominant-negative form of MEF2D, without its transactivation domain, in HL60 cells. When the HL60 cell line expressing the mutant MEF2D was induced to differentiate by VitD(3) treatment, cell surface expression of CD14 and the ability to reduce NBT, which are important characteristics of differentiated monocytes, were significantly decreased compared with control HL60 cells. These results show that MEF2D is required in the differentiation process along the monocyte/macrophage lineage,

CD28-mediated regulation of the c-jun promoter involves the MEF2 transcription factor in Jurkat T cells

Within a few minutes of T-cell activation, transcription of a set of genes including c-fos and c-jun is activated. For maximal induction of c-jun, at least two major signal pathways are required. One can be triggered by T-cell receptor engagement or phorbol esters and the other by anti-CD28 engagement. The c-jun promoter region between -117 and -50 contains binding sites for the transcription factors Spl, CTF, ATF/CREB, and MEF2. In this study, we sought to map the sequences in the c-jun promoter responsible for CD28-mediated induction in activated Jurkat T cell by point mutational analysis. We found that mutation of the c-jun MEF2 site strongly reduces CD28 induction of the promoter in Jurkat T cells and that MEF2D is the major binding molecule to the c-jun MEF2 site in Jurkat T cells. Mutation of the c-jun ATF site also partially reduced CD28 induction of the promoter. In addition, pretreatment with an endolysomotropic agent NH4Cl, an acidic sphingomyelinase inhibitor, completely inhibited the activation of the c-jun promoter by anti-CD28 antibody treatment, whereas pretreatment with wortmannin, a PI3-kinase inhibitor, did not affect the induction of the c-jun promoter. These results suggest that CD28 signaling leading to the c-jun promoter involves acidic sphingomyelinase, but not PI3-kinase, to activate factors binding to the MEF2 and ATF sites.

Mapping of antigenic determinant regions of the Bor56 protein of Orientia tsutsugamushi

The 56-kDa protein (Bor56) of Orientia tsutsugamushi is an immunoprotective antigen and is the target molecule of neutralizing antibodies. This antigen is recognized by almost all of the serum antibodies produced by patients in the convalescence phase of scrub typhus. We expressed the Bor56 open reading frame in Escherichia coli and generated from it a series of deletion constructs as MalE fusion proteins. Antibody-binding domains were characterized by using patient sera, mouse monoclonal antibodies (MAbs), and Bor56-immunized-mouse sera. None of the antibodies bound to a fusion protein containing the carboxy-terminal 140 amino acids (aa) of the Bor56 protein, suggesting that the carboxy-terminal domain of Bor56 is not exposed on the surface of the molecule. Human immunoglobulin M (IgM) antibodies predominantly bound to antigenic domain I (AD I; amino acids [aa] 19 to 113) and AD III (aa 243 to 328). Human IgG antibodies also showed preferential binding to AD I. The epitope recognized by strain-specific MAb (KI4) or group-specific MAb (KI57) was mapped to AD II (aa 142 to 203). Mouse serum antibodies, elicited by immunization with deletion mutants, consistently bound to AD III. Moreover, the carboxy-terminal 140 aa of the Bor56 protein did not elicit an antibody response in C3H/HeDub mice. A model of the antigenic structure of Bor56 is presented and discussed. These results suggest that antigenic fragments from AD I and AD III are useful in the induction of humoral immunity against O. tsutsugamushi. These antigenic analyses provide an important foundation for further analyses of the neutralizing-antibody responses generated during rickettsial infections. They also provide potential peptide substrates for diagnostic assays and vaccine strategies.

Induction of neutralizing antibody in mice by immunization with recombinant 56 kDa protein of Orientia tsutsugamushi

Anti-oriential antibody inhibits Orientia tsutsugamushi attachment to, and penetration of, host cells. However, O. tsutsugamushi antigens that induce the production of a neutralizing antibody have not been identified. The authors immunized mice and rabbits with the recombinant 56 kDa protein of O. tsutsugamushi fused to the maltose binding protein of Escherichia coli (MBP-Bor56) and analysed their effect on O. tsutsugamushi attachment to or penetration of L929 cells. O. tsutsugamushi attachment and penetration were measured by using an indirect immunofluorescent antibody assay (IFA). O. tsutsugamushi growth in L929 cells was determined by [3H]thymidine uptake assay. By IFA, we observed a 96% reduction of attachment or penetration of O. tsutsugamushi treated with rabbit anti-MBP-Bor56 sera. [3H]thymidine uptake showed that mouse anti-MBP-Bor56 sera caused a 91% reduction in O. tsutsugamushi growth, when compared to mouse anti-MBP sera. These results suggest that the 56 kDa protein of O. tsutsugamushi plays an important role in O. tsutsugamushi attachment to or penetration of cells.

Isolation of a new Orientia tsutsugamushi serotype

Orientia tsutsugamushi, the etiological agent of scrub typhus, is an antigenically diverse organism and many serologically distinct strains have been identified. The 56 kDa protein of O. tsutsugamushi, a major protein in the outer membrane, has been thought to be responsible for this antigenic variability. A strain of O. tsutsugamushi isolated in Korea cross-reacted with both Gilliam strain-specific and Karp strain-specific monoclonal antibodies. When its 56 kDa protein gene was cloned and analyzed, its sequence showed variation especially between 1,200 and 1,250 bp, showing that this isolate is a new O. tsutsugamushi strain.

Regulatory role of MEF2D in serum induction of the c-jun promoter

Serum induction of c-jun expression in HeLa cells requires a MEF2 site at -59 in the c-jun promoter. MEF2 sites, found in many muscle-specific enhancers, are bound by a family of transcription factors, MEF2A through -D, which are related to serum response factor in their DNA binding domains. We have found that MEF2D is the predominant protein in HeLa cells that binds to the c-jun MEF2 site. Serum induction of a MEF2 reporter gene was not observed in a line of NIH 3T3 cells which contain low MEF2 site binding activity. Transfection of MEF2D into NIH 3T3 cells reconstituted serum induction, demonstrating that MEF2D is required for the serum response. Deletion analysis of MEF2D showed that its DNA binding domain, when fused to a heterologous transcriptional activation domain, was sufficient for serum induction of a MEF2 reporter gene. This is the domain homologous to that in the serum response factor which is required for serum induction of the c-fos serum response element, suggesting that serum regulation of c-fos and c-jun may share a common mechanism.

A fluorescent in situ hybridization analysis of the chromosome constitution of ejaculated sperm in a 47,XYY male

Two semen samples from a 47,XXY male were examined using chromosome-specific DNA probes and fluorescent in situ hybridization (FISH) to determine the distribution of sex chromosomes and an autosome (chromosome 17) in the sperm. A motile population of sperm was also prepared from one sample using the swim-up technique to compare the motile and total sperm populations. Chromosomes were localized using single FISH and a biotinylated chromosome 17 probe (TR17), or double FISH using a biotinylated X chromosome probe (TRX) and a digoxigenin-labelled Y chromosome probe (HRY). Labelling efficiencies were 95-98%. Ploidy levels were estimated by measurement against a microscope eye-piece graticule. The overall ratio of X- to Y-bearing sperm was 47% to 48.4% in the neat samples, and 48.4% to 45.3% in the swim-up fraction. Neither of the ratios was significantly different from 1:1. The frequencies of monosomic and disomic (but otherwise haploid sperm) were not different from the frequencies we observed in normal donors. In contrast, the frequencies of both diploid and tetraploid cells were increased in the neat samples of the XYY male. In the swim-up fractions, however, none of these parameters differed from those of ten normal semen donors. These results support the hypothesis that the extra Y chromosome in XYY men is eliminated during spermatogenesis.

Mapping of epidermal growth factor-, serum-, and phorbol ester-responsive sequence elements in the c-jun promoter

Expression of the nuclear proto-oncogene c-jun is rapidly and transiently induced by many growth factors, serum, and tumor promoters. The sequence elements in the c-jun promoter involved in serum or growth factor induction have not been identified. The c-jun promoter region between -117 and -72 contains binding sites for the transcription factors Sp1, CTF, and AP-1. An additional sequence element has been noted at position -59. This A+T-rich sequence, formerly proposed as a TFIID-binding site, conforms to the consensus binding sequence of a recently identified factor, RSRF (related to serum response factor). In this study, we mapped the sequences in the c-jun promoter responsible for epidermal growth factor (EGF), serum, and 12-O-tetradecanoylphorbol-13-acetate (TPA) induction by deletion and point mutational analysis. We found that the c-jun RSRF site is an important element for EGF and serum induction of the promoter and that there are several factors in HeLa nuclear extracts which specifically bind to this site. The RSRF site was also sufficient for EGF, serum, and TPA induction when assayed on a heterologous promoter. The c-jun AP-1 site was not required for EGF, serum, or TPA induction but was sufficient to mediate a weak response to these agents when assayed on a heterologous promoter. Double mutation of the RSRF and AP-1 sites suggests that there is an additional TPA-responsive element between -80 and +150 in the c-jun promoter.

A putative transmembrane protein with histidine-rich charge clusters encoded in the H-2K/tw5 region of mice

The H-2 complex of mice contains many genes in addition to the gene families involved in immune reactions. Some of them are believed to function in mouse development, as suggested by the findings that several embryonic lethal mutations map within or near the H-2 complex. We have analyzed the H-2K/tw5 region in an attempt to study non-H-2 genes encoded in this region. Overlapping cosmid clones spanning about 170 kilobase pairs of DNA, including the H-2K/tw5 region of the mouse, have been screened for genes expressed in embryonic carcinoma cells. A transcript of 2.8 kilobase pairs (K. Abe. J.-F. Wei, F.-S. Wei, Y.-C. Hsu, H. Uehara, K. Artzt, and D. Bennett, EMBO J. 7:3441-3449, 1988) encoded by the KE 4 gene flanking H-2K distally was identified. The transcript was abundantly expressed in embryonic carcinoma cells but was present at low levels in other tissues in adults. A cDNA for this transcript was isolated from the F9 embryonic carcinoma cell line and sequenced. It potentially encodes a protein of 436 amino acids with several interesting features. First, it contains two regions made of well-conserved repeats unusually rich in histidine residues. In the repeats, histidine alternates with other amino acids, notably glycine or serine. Second, the two histidine-rich regions are separated by three putative membrane-spanning domains. Third, the N-terminal part of the sequence shows characteristics of a signal peptide. The results indicate that the protein coded by the gene may be a transmembrane protein with histidine-rich charge clusters. A similar sequence motif found in other known genes allows speculation on the possible functional of this gene.