Two-dimensional Rydberg gases and the quantum hard-squares model

We study a two-dimensional lattice gas of atoms that are photoexcited to Rydberg states in which they interact via the van der Waals interaction. We explore the regime of dominant nearest-neighbor interaction where this system is intimately connected with a quantum version of Baxter's hard-squares model. We show that the strongly correlated ground state of the Rydberg gas can be analytically described by a projected entangled pair state that constitutes the ground state of the quantum hard-squares model. This correspondence allows us to identify a phase boundary where the Rydberg gas undergoes a transition from a disordered (liquid) phase to an ordered (solid) phase.

116 IMPROVED SURVIVAL BY CRYOPRESERVING RHESUS MACAQUE (MACACA MULATTA) SPERMATOZOA WITH DIRECTIONAL FREEZING TECHNIQUE

A significant increase in nonhuman primate models of human diseases will be expected in the near future since the successes in production of genetically engineered rhesus monkey models of human diseases. Sperm banking can provide an effective way to preserve valuable genetic resources. Our objective was to (1) develop a protocol using directional freezing technique (DFT) for rhesus monkey spermatozoa cryopreservation, which allows precise control of the velocity and the morphology of the ice-front propagation by transferring the tubes loaded with 2 mL sperm samples at a controllable velocity through two separate chambers with controllable temperature settings, and (2) achieve survival rate that was higher than that achieved with conventional freezing technique (CFT), by which sperm samples were cryopreserved in 0.25 mL straws with liquid nitrogen vapor in a styrofoam box. Sperm motility, acrosomal integrity, and in vitro fertilization (IVF) assay were used to assess the function of frozen-thawed spermatozoa. Data were analyzed by ANOVA and Fisher protected LSD test. Experiment 1 was aimed at optimizing the cooling rate using DFT. Tubes were frozen using the multi-thermal gradient freezing device (MTG 516, Harmony CryoCareTM, IMT Ltd.) at fast (16°C/min), medium (12°C/min), and slow (7°C/min) cooling rates, which corresponded to the transferring velocities (2.5, 1.5, and 0.5 mm s-1, respectively). The results showed that spermatozoa frozen at fast and medium cooling rates showed significantly higher frozen-thawed motility than those frozen at slow cooling rate (61% and 59% v. 50%, P < 0.05). However, no difference was observed on sperm acrosomal integrity among the experimental groups (84, 80, and 78%, respectively, P > 0.05). The purposes of Experiment 2 were determined to examine if using DFT at the optimized cooling rate (12°C/min) can improve the cryo-survival of rhesus monkey spermatozoa compared with CFT. Our results showed that spermatozoa cryopreserved by using DFT achieved significantly higher frozen-thawed sperm motility that those cryopreserved by using CFT (64 v. 54%, P < 0.05). However, no difference was observed on acrosomal integrity between spermatozoa cryopreserved by DFT and CFT (84 and 83%, respectively; P > 0.05). The function of spermatozoa cryopreserved by using DFT was further evaluated by IVF. Females were treated with rhFSH twice-daily for 8 days after the onset of menses and following a treatment of hCG injection on Day 9. Cumulus-oocyte complexes were collected by laparoscopic follicular aspiration 32 h later. Of the inseminated oocytes, 79% were fertilized and 90 and 53% of the resulting zygotes developed into 2-cell and blastocysts, respectively. The fertilization rate was lower and the blastocyst rate was slightly higher than our previous report when fresh spermatozoa were used for IVF (94 and 52%, respectively). Our results indicate that spermatozoa of rhesus monkeys can be effectively cryopreserved using DFT in large volume. This finding provided a new and effective way for genetics preservation purposes in this important species.

Spin-lattice order in frustrated ZnCr2O4

Using synchrotron x-ray and neutron diffraction, we disentangle spin-lattice order in highly frustrated ZnCr2O4 where magnetic chromium ions occupy the vertices of regular tetrahedra. Upon cooling below 12.5 K the quandary of antialigning spins surrounding the triangular faces of tetrahedra is resolved by establishing weak interactions on each triangle through an intricate lattice distortion. However, the resulting spin order is not simply a Néel state on strong bonds, but rather a complex coplanar spin structure, indicating that antisymmetric and/or further neighbor exchange interactions also play a role as ZnCr2O4 resolves conflicting magnetic interactions.

Weakly coupled s=1/2 quantum spin singlets in Ba3Cr2O8

Using single crystal inelastic neutron scattering with and without the application of an external magnetic field and powder neutron diffraction, we have characterized magnetic interactions in Ba3Cr2O8. Even without a field, we found that there exist three singlet-to-triplet excitation modes in the (h, h, l) scattering plane. Our complete analysis shows that the three modes are due to spatially anisotropic interdimer interactions that are induced by lattice distortions of the tetrahedron of oxygens surrounding the Jahn-Teller active Cr5+(3d1). The strong intradimer coupling of J0=2.38(2) meV and weak interdimer interactions (|Jinter|< or =0.52(2) meV) makes Ba3Cr2O8 a good model system for weakly coupled s=1/2 quantum spin dimers.

Tripterygium wilfordii hook f increase the blood concentration of tacrolimus

OBJECTIVE

To observe the influence of the Tripterygium wilfordii Hook F (T II) on the blood concentration of tacrolimus and analyze the impact of this effect.

METHOD

Twenty-two renal transplant receipts taking tacrolimus combined with the T II were selected for this study. We analyzed the blood concentrations and the rate of concentration compared with dosage (C/D rate) pre- and postcombination over 6 months. All cases underwent the CYP3A5 genotype test.

RESULT

The concentrations of tacrolimus were raised to a certain degree after the combination in all the cases. The first-time elevation differed from 1 week to 4 months. The C/D rate increased by 1.7 to 7.2 times with most evaluated C/D rates ranging from 1.8 to 3.8. The elevated C/D rate of the subgroup of CYP3A5 1/1 and 1/3 (n = 10) contrasted with the 3/3 genotype subgroup (n = 12: 2.99 +/- 1.71 vs 2.55 +/- 1.07; P = .472). The mycophenolate mofetil subgroup (n = 17) was not contrasted to the mizoribine subgroup (n = 5: 2.85 +/- 1.51 vs 2.31 +/- 0.26; P = .498).

CONCLUSION

T II considerably increased the blood concentration and the C/D rate of tacrolimus. The degree of increase was probably not related to the CYP3A5 genotype and the combination of immunosuppressive agents.

External magnetic field effects on a distorted kagome antiferromagnet

We report bulk magnetization, and elastic and inelastic neutron scattering measurements under an external magnetic field H on the weakly coupled distorted kagome system, Cu2(OD)3Cl. Our results show that the ordered state below 6.7 K is a canted antiferromagnet and consists of large antiferromagnetic ac components and smaller ferromagnetic b components. By first-principles calculations and linear spin wave analysis, we present a simple spin Hamiltonian with nonuniform nearest neighbor exchange interactions resulting in a system of coupled spin trimers with a single-ion anisotropy that can qualitatively reproduce the spin dynamics of Cu2(OD)3Cl.

Observation of efficacy and safety of converting the calcineurin inhibitor to sirolimus in renal transplant recipients with chronic allograft nephropathy

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of converting from a calcineurin inhibitor (CNI) to sirolimus among renal transplant recipients with chronic allograft nephropathy (CAN).

METHODS

In 16 patients with CAN, substituted sirolimus for CsA or FK506 and observed the incidence of acute rejection and changes in serum creatinine, triglycerides, cholesterol, blood uric acid, and peripheral blood leukocyte/platelet counts within 12 months. All recipients underwent an allograft biopsy before conversion. The targeted sirolimus level was 4-8 ug/L.

RESULTS

After conversion to sirolimus, the creatinine level of 7 cases decreased and the efficacy rate was (43.8%). No acute rejection occurred during the follow-up. The cases with hypercholesteremia increased from 3 to 7 after conversion; hypertriglyceridemia increased from 3 to 5; leukopenia occurred in 2; subnormal platelet counts increased from 2 to 3; and hyperuricemia increased from 6 to 7. Meanwhile, the average level of peripheral blood leukocytes obviously decreased in the first month, the average peripheral blood cholesterol increased over 12 months, but the average content of peripheral blood platelets, triglyceride and blood uric acid failed to display as statistic difference. Eight patients showed C4d deposition in peritubular capillary in graft tissue before conversion, 7 cases of whom showed no improvement in renal function. In 6 cases there was no C4d deposition in peritubular capillary in graft tissue. Only 2 of 6 cases showed no improvement in renal function. There were 6 patients whose creatinine level was <2.48 mg/dL before conversion, and renal function in 5 of them improved in a year after conversion. In contrast, among 10 patients whose blood creatinine level was >2.48 mg/dL, only 2 cases improved.

CONCLUSION

It is safe for patients with CAN to use substitute sirolimus for CNI; the incidence of acute rejection did not increase. In this study, 43.8% of patients showed improved renal function. The main adverse reactions after conversion to sirolimus were hypercholesteremia and decreased peripheral blood leukocytes. The serum creatinine level and the deposition of C4d in peritubular capillary were important factors influencing therapeutic efficacy.

Ability of oral bacteria to induce tissue-destructive molecules from human neutrophils

AIM

The induction of tissue-destructive molecules from neutrophils by periodontopathic bacteria has been suggested as one of the mechanisms of periodontal destruction. The aim of this study was to determine whether the ability to stimulate neutrophils is an authentic characteristic of periodontopathic bacteria.

METHODS

We evaluated, along with phagocytosis, the production of reactive oxygen species (ROS), matrix metalloproteinase-8 (MMP-8), and interleukin-1beta by neutrophils in response to non-periodontopathic Streptococcus sanguinis and periodontopathic bacteria Fusobacterium nucleatum and Treponema denticola, in the absence or presence of antibodies. Phagocytosis, the death of neutrophils, and intracellular ROS production were measured by flow cytometry and the concentrations of MMP-8 and interleukin-1beta secreted into medium were determined by enzyme-linked immunosorbent assay.

RESULTS

S. sanguinis and F. nucleatum induced greater production of ROS, MMP-8, and interleukin-1beta than did T. denticola. The levels of tissue-destructive molecules produced by neutrophils had a positive correlation with phagocytosis. Opsonization of bacteria with antibodies significantly increased phagocytosis and ROS production and release, thus increasing both bacterial clearance and potential tissue damage.

CONCLUSION

The ability of oral bacteria to induce tissue-destructive molecules from neutrophils is not an inherent characteristic of periodontopathic bacteria, which would provide a new insight into the role of neutrophils in periodontal destruction.

Innate immune responses of gingival epithelial cells to nonperiodontopathic and periodontopathic bacteria

BACKGROUND AND OBJECTIVE

We have previously reported different susceptibilities of periodontopathic and nonperiodontopathic bacteria to antimicrobial peptides and phagocytosis by neutrophils. Differences between the two groups of bacteria may exist also in their ability to induce immune responses from the host. Therefore, we evaluated the effects of various oral bacteria on innate immune responses by gingival epithelial cells.

MATERIAL AND METHODS

HOK-16B cells were cocultured with live or lysed nonperiodontopathic (n = 3) and periodontopathic (n = 5) bacterial species. The levels of human beta defensin-1, -2 and -3, and of the cathelicidin, LL-37, were examined by real-time reverse transcription-polymerase chain reaction, and the accumulated interleukin-8 and interleukin-1 alpha were measured by enzyme-linked immunosorbent assay.

RESULTS

Nonperiodontopathic bacteria up-regulated some antimicrobial peptides without affecting the levels of cytokines. In the periodontopathic group, the orange-complex bacteria induced antimicrobial peptides and interleukin-8 efficiently, but the red-complex bacteria often demonstrated suppressive effects. In contrast to live bacteria, bacterial lysates had no suppressive effects. In addition, some bacterial lysates demonstrated a reduced ability to induce antimicrobial peptides compared with live bacteria.

CONCLUSION

The nonperiodontopathic, the orange-complex, and the red-complex bacteria had different effects on the innate immune responses from gingival epithelial cells, which may affect the outcome of their host-microbial interaction in gingival sulcus.

Non-resonant and resonant x-ray scattering studies on multiferroic TbMn2O5

Comprehensive x-ray scattering studies, including resonant scattering at Mn L, Tb L, and M edges, were performed on single crystals of TbMn2O5 for crystallographic data to elucidate the nature of its commensurate and incommensurate phases. The scattering results provide direct evidence of symmetry lowering to the ferroelectric phase driven by magnetically induced lattice modulations and show the presence of multiple magnetic orders. The competing orders under spin-frustrated geometry are believed to cause discommensuration and result in the commensurate-to-incommensurate phase transition around 24 K. It is proposed that the low temperature incommensurate phase consists of commensurate domains separated by antiphase domain walls which change both signs of spontaneous polarizations and x-ray scattering amplitudes for forbidden reflections.

Susceptibility of various oral bacteria to antimicrobial peptides and to phagocytosis by neutrophils

BACKGROUND AND OBJECTIVE

The aim of this study was to compare the susceptibility of nonperiodontopathic and periodontopathic bacteria to major defense mechanisms for bacterial clearance in gingival sulcus.

MATERIAL AND METHODS

Twenty strains of 13 oral bacterial species were studied for their susceptibility to phagocytosis by human neutrophils and to the antimicrobial peptides LL-37 and human beta defensin-3. The minimum inhibitory concentrations of LL-37 and human beta defensin-3 were determined by a liquid dilution assay, and susceptibility to phagocytosis was examined by a flow cytometric phagocytosis assay.

RESULTS

The minimum inhibitory concentrations of LL-37 and human beta defensin-3 varied greatly, depending on the strain and species. Although a significant difference between the non- and periodontopathic groups was not observed, the red-complex bacteria were more resistant to LL-37 than the others (p=0.004). The susceptibility of oral bacteria to phagocytosis was quite variable, depending on the species but not on the strains. The periodontopathic bacteria, especially Actinobacillus actinomycetemcomitans and the red-complex triad, were more resistant to phagocytosis than were the nonperiodontopathic bacteria (p=0.0003). In addition, bacteria resistant both to antimicrobial peptides and to phagocytosis were more common in the periodontopathic group.

CONCLUSION

Our results indicate that immune evasion may contribute to the pathogenicity of some periodontopathic bacteria.

Resonant X-ray scattering study of quadrupole-strain coupling in DyB4

X-ray and neutron scattering studies were performed on DyB4 which exhibits both a quadrupolar ordering and a macroscopic lattice distortion. A forbidden reflection at 7.792 keV near the Dy L3 absorption edge is identified as a quadrupolar ordering peak, and the quadrupolar order and a monoclinic structural distortion develop concomitantly below 12.3 K as second-order-type phase transitions. Coupling between the quadrupolar order and the strain in DyB4 is directly demonstrated by observing that both order parameters are proportional to each other.

Treatment of early mixed cellular and humoral renal allograft rejection with tacrolimus and mycophenolate mofetil

This prospective study investigated the efficiency of the tacrolimus (Tac) combined with mycophenolate mofetil (MMF) alone without immunoadsorption (IA) or plasmapheresis (PPH) as treatment for early (within 2 weeks) acute humoral rejection (AHR) in non-sensitized renal allograft recipients. Of 160 patients enrolled in this prospective study, 11 patients had histologically and clinically confirmed early steroid-resistant acute rejection with an antibody response and received Tac-MMF therapy. No other aggressive rescue methods such as IA, PPH were used, according to the study design. Patients (n=11) were followed for 13.8+/-3.5 months; nine were females. The complement-dependent cytotoxicity crossmatch was negative before transplantation in all patients and only positive for panel-reactive antibody in one patient. Most of the rejection episodes were mixed with cellular rejection (four patients met Banff IIA criteria, five patients met Banff IIB, one patient met Banff IB, and one patient met Banff borderline). After 16.19+/-6.16 days of treatment, all rejection episodes were successfully reversed and all graft functions were stable, with a mean serum creatinine level of 1.12+/-0.32 mg/dl during follow-up. No patient suffered from severe infectious complications (except one case of urinary infection). Our investigation suggests that Tac combined with MMF alone is adequate to reverse early mixed cellular and humoral C4d-positive rejection in non-sensitized renal allograft recipients.

Late and early C4d-positive acute rejection: Different clinico-histopathological subentities in renal transplantation

This study was performed to investigate the clinical and pathologic features of C4d-positive steroid-resistant acute rejection (AR) at different phases after renal transplantation. Fifty-six kidney allograft recipients with C4d-positive AR were divided into three groups, very early rejection (VER, occurring < or =14 days following transplantation, n=28), early rejection (ER, occurring 15-180 days following transplantation, n=5), and late rejection (LR, occurring >180 days following transplantation, n=23). Clinical and pathological features were evaluated. Significantly more patients in the ER and LR groups were associated with a reduction or withdrawal of immunosuppressants. More patients in the ER and LR groups experienced a significant (>3 g/l) decrease in serum albumin (80% ER, 91.3% LR, 7.1% VER, P<0.001) and a decrease in hemoglobin (>1 g/dl) (80, 100 vs 17.9%, P<0.001). Most VER patients reported a fever and had very rapid graft dysfunction requiring dialysis. Significantly more patients (87%) had interstitial fibrosis and tubular atrophy in the LR group compared with the other groups and 13% had transplant glomerulopathy. Most cases of VER were reversed with tacrolimus and mycophenolate mofetil treatment, with or without immunoadsorption, with a 1-year survival rate of 96.4%, compared with only 60 and 52.2% in the ER and LR groups. In conclusion, C4d-positive steroid-resistant AR at different time points is associated with unique clinico-histopathological manifestations requiring distinct treatment strategies. Late episodes are usually associated with significantly reduced serum albumin and hemoglobin levels and a poorer outcome. A more specialized treatment protocol should be established for these patients.

Changes in steady-state concentrations of messenger ribonucleic acids in luteal tissue during prostaglandin F2α induced luteolysis in mares

Transvaginal ultrasound-guided luteal biopsy was used to evaluate the effects of prostaglandin (PG)F2alpha on steady-state concentrations of mRNA for specific genes that may be involved in regression of the corpus luteum (CL). Eight days after ovulation (Hour 0), mares (n=8/group) were randomized into three groups: control (no treatment or biopsy), saline+biopsy (saline treatment at Hour 0 and luteal biopsy at Hour 12), or PGF2alpha+biopsy (5mg PGF2alpha at Hour 0 and luteal biopsy at Hour 12). The effects of biopsy on CL were compared between the controls (no biopsy) and saline+biopsy group. At Hour 24 (12h after biopsy) there was a decrease in circulating progesterone in saline group to 56% of pre-biopsy values, indicating an effect of biopsy on luteal function. Mean plasma progesterone concentrations were lower (P<0.001) at Hour 12 in the PG group compared to the other two groups. The relative concentrations of mRNA for different genes in luteal tissue at Hour 12 was quantified by real time PCR. Compared to saline-treated mares, treatment with PGF2alpha increased mRNA for cyclooxygenase-2 (Cox-2, 310%, P<0.006), but decreased mRNA for LH receptor to 44% (P<0.05), steroidogenic acute regulatory protein to 22% (P<0.001), and aromatase to 43% (P<0.1) of controls. There was no difference in mRNA levels for PGF2alpha receptor between PG and saline-treated groups. Results indicated that luteal biopsy alters subsequent luteal function. However, the biopsy approach was effective for collecting CL tissue for demonstrating dynamic changes in steady-state levels of mRNAs during PGF2alpha-induced luteolysis. Increased Cox-2 mRNA concentrations suggested that exogenous PGF2alpha induced the synthesis of intraluteal PGF2alpha. Thus, the findings are consistent with the concept that an intraluteal autocrine loop augments the luteolytic effect of uterine PGF2alpha in mares.

Fates and targets of male accessory gland proteins in mated female Drosophila melanogaster

Male accessory gland proteins (Acps) in Drosophila are components of the seminal fluid and are transferred to females during copulation. In mated females, Acps enhance egg production, augment sperm storage, induce refractory mating behaviors, and affect the female's longevity. To address the functions of eight previously uncharacterized Acps and further analyze five others, we determined the tissues to which they target after transfer to females. Each Acp has multiple targets and is unique in its pattern of localization. Within the reproductive tract, Acps target to the uterus, oviduct, sperm storage organs, ovary and oocytes. Some Acps also leave the reproductive tract, to enter the hemolymph. Some Acps are detected on the surface of eggs laid by mated females but were not detectable within those eggs. Our results can help to identify the likely functions of these Acps as well as to create models for the mechanism of action of Acps.

Variation of CD4+ and CD8+ T Lymphocytes as Predictor of Outcome in Renal Allograft Recipients Who Developed Acute Respiratory Distress Syndrome Caused by Cytomegalovirus Pneumonia

INTRODUCTION

We investigated the variation of CD4+ and CD8+ T lymphocytes in renal allograft recipients who developed acute respiratory distress syndrome (ARDS) caused by cytomegalovirus (CMV) infection and their relationship to patients outcome.

METHODS

Twenty one cadaveric renal allograft recipients who developed ARDS caused by CMV infection were enrolled in this study. CD4+ and CD8+ T lymphocytes were examined in peripheral blood on five occasions: the admission day (day 0) to ICU as ARDS, day 5, day 10, day 15 in ICU, and discharge day. A value taken in the second month after transplantation was assumed to be the preinfection value.

RESULTS

Among 13 surviving patients, the numbers of CD4+ and CD8+ T cells and their ratio increased as the patients recovered. The numbers of CD4+ T cells increased significantly on day 10, day 15, and at discharge day compared with day 0 (P < .05). The number of CD8+ T cells on discharge day and the ratios after day 10 were also significantly higher than those on day 0 (P < .05). In eight nonsurviving patients, the numbers of CD4+ and CD8+ T cells and their ratio was similar to day 0. The number of CD4+ and CD8+ cells after day 5 and their ratio after day 10 were significantly lower than those of survival group (P < .05).

CONCLUSION

The variations of CD4+ and CD8+ T lymphocytes and their ratio are useful indicators of the severity of disease and the outcome of patients with CMV infections accompanying ARDS after renal transplantation. Nevertheless, it may be helpful to evaluate the efficiency of ongoing treatment methods in these patients.

Measurement of strain in physical models of brain injury: a method based on HARP analysis of tagged magnetic resonance images (MRI)

Two-dimensional (2-D) strain fields were estimated non-invasively in two simple experimental models of closed-head brain injury. In the first experimental model, shear deformation of a gel was induced by angular acceleration of its spherical container In the second model the brain of a euthanized rat pup was deformed by indentation of its skull. Tagged magnetic resonance images (MRI) were obtained by gated image acquisition during repeated motion. Harmonic phase (HARP) images corresponding to the spectral peaks of the original tagged MRI were obtained, following procedures proposed by Osman, McVeigh and Prince. Two methods of HARP strain analysis were applied, one based on the displacement of tag line intersections, and the other based on the gradient of harmonic phase. Strain analysis procedures were also validated on simulated images of deformed grids. Results show that it is possible to visualize deformation and to quantify strain efficiently in animal models of closed head injury.

Cloning and sequence analysis of dsRNA segments 5, 6 and 7 of a novel non-group A, B, C adult rotavirus that caused an outbreak of gastroenteritis in China

A diarrhoeal outbreak among adults in China was caused by a new rotavirus, termed ADRV-N, that does not react with antisera directed against group A, B or C rotaviruses [Zhonghua Liu Xing Bing Xue Za Zhi (Chin. Epidemiol.) 19 (1998) 336]. ADRV-N can be propagated in cell cultures [Zhonghua Yi Xue Za Zhi (Natl. Med. J. China) 82 (2002) 14]. We present the complete sequences for ADRV-N genome segments 5 and 6, and a full ORF sequence of genome segment 7. The deduced amino acid sequences suggest that these segments encode NSP1, VP6 and NSP3, respectively. These three ADRV-N genome segments have a unique -ACCCC-3' terminal sequence. The 5'-GG- terminus of segments 5 and 6 is the same as that of other rotaviruses. The amino acid similarity between VP6 and NSP3 of ADRV-N and the cognate sequences of their closest counterpart, group B IDIR, was 37 and 35%, respectively. The ADRV-N NSP1 has a double-stranded RNA binding motif (DSRM) and a putative autoproteolytic cleavage motif upstream from the DSRM. The putative ADRV-N NSP3 has a truncated C-terminus compared to the cognate protein of group B rotaviruses. All the available data demonstrate that ADRV-N differs significantly from the known rotaviruses and strongly suggest that ADRV-N is the first recognized member of a new group of rotaviruses infecting humans.