Use of short echo time two-dimensional 1H-magnetic resonance spectroscopy in temporal lobe epilepsy with negative magnetic resonance imaging findings

We evaluated short echo time two-dimensional 1H magnetic resonance spectroscopy (2D-1HMRS) with the point-resolved spatial selection (PRESS) protocol in temporal lobe epilepsy (TLE) patients with negative magnetic resonance imaging (MRI) findings and described the characteristics of 2D-(1)HMRS in the epileptic focus. Thirty-eight TLE patients with negative conventional MRI findings and 10 healthy controls were studied by 2D-1HMRS. A 128-channel prolonged video-electroencephalographic (EEG) method was used as the standard for epileptogenic focus localization to evaluate N-acetyl aspartate/(choline + creatine + phosphocreatine) (NAA/[Cho + Cr-PCr]), glutamate + glutamine/creatine (Glx/Cr-PCr) and myo-inositol/Cr-PCr ratios in patients with negative MRI findings. The 2D-1HMRS showed that 32/38 patients and all healthy controls had stable baselines and good signal-to-noise ratios. Compared with the healthy controls, 32 patients showed abnormal NAA/(Cho + Cr-PCr) ratios in the hippocampus and, in 25 of these patients, focus lateralization agreed with the EEG. It is concluded that short echo time 2D-1HMRS with the PRESS protocol can help find abnormalities in lateralization of temporal epilepsy in patients with negative MRI findings.

In vivo selection of human embryonic stem cell-derived cells expressing methotrexate-resistant dihydrofolate reductase

Human embryonic stem cells (hESCs) provide a novel source of hematopoietic and other cell populations suitable for gene therapy applications. Preclinical studies to evaluate engraftment of hESC-derived hematopoietic cells transplanted into immunodeficient mice demonstrate only limited repopulation. Expression of a drug resistance gene, such as Tyr22-dihydrofolate reductase (Tyr22-DHFR), coupled to methotrexate (MTX) chemotherapy has the potential to selectively increase engraftment of gene-modified hESC-derived cells in mouse xenografts. Here, we describe the generation of Tyr22-DHFR – GFP expressing hESCs that maintain pluripotency, produce teratomas and can differentiate into MTXr-hemato-endothelial cells. We demonstrate that MTX administered to nonobese diabetic/severe combined immunodeficient/IL-2Rγc^null (NSG) mice after injection of Tyr22-DHFR-derived cells significantly increases human CD34⁺ and CD45⁺ cell engraftment in the bone marrow (BM) and peripheral blood of transplanted MTX-treated mice. These results demonstrate that MTX treatment supports selective, long-term engraftment of Tyr22-DHFR-cells in vivo, and provides a novel approach for combined human cell and gene therapy.

Prevalence, risk factors and outcome of digital gangrene in 2684 lupus patients

The aim of the study is to assess the clinical characteristics, risk factors and outcome of patients with systemic lupus erythematosus (SLE) complicated with digital gangrene. In all, 2684 consecutive SLE inpatients admitted to Peking Union Medical College Hospital from December 1997 to August 2007 were studied. Demographic data, clinical features, laboratory findings as well as therapeutic regimens were systematically reviewed and a database was established. Cases with digital gangrene were identified and followed up. 1) Eighteen patients with SLE were complicated with digital gangrene, the average age at event was 33.1 ± 11.8 years and the average disease duration was 99.1 ± 60.1 months. 2) Patients with SLE, with long disease duration (≥4 years), Raynaud’s phenomenon and elevated serum C-reactive protein (CRP) were more likely to develop digital gangrene, P = 0.006, 0.001, and 0.031, respectively, OR = 1.03 (95% CI 1.01, 1.04), 35.76 (95% CI 4.67, 273.83) and 9.93 (95% CI 1.23, 80.30), respectively. 3) Fifteen gangrene patients started prednisone ≥1 mg/kg/d, and 18 were treated with cyclophosphamide, although 8 cases failed and ultimately received digital amputation. Prompt corticosteroid treatment (prednisone ≥1 mg/kg/d started within 3 weeks) decreased the hazard of amputation, P = 0.073, HR = 0.13 (95% CI 0.01, 1.21). Long disease duration, Raynaud’s phenomenon and elevated serum CRP were independent predictive factors for SLE to develop digital gangrene. Early and aggressive corticosteroid treatment prevented gangrene from progression and improved prognosis.

Protective factors relating to decreased risks of adolescent suicidal behaviour

BACKGROUND

Suicide has been identified as one of the three leading causes of death in adolescents and young adults. No previous study in China has tested the association between protective factors and urban adolescents' suicidal behaviours. In this study we tested the hypothesis that suicidal behaviours would be associated with multiple protective factors.

METHODS

A stratified random of 9015 students from 100 junior middle schools in Beijing, Hangzhou, Wuhan and Urumqi completed the Chinese version of Global School-Based Student Health Survey.

RESULTS

Overall, 17.4% of students had seriously considered attempting suicide, and 8.1% had made a specific plan to attempt suicide during the 12 months preceding the survey. The students in Wuhan (18.7%) and Urumqi (20.8%) cities were significantly more likely than students in Beijing (14.4%) and Hangzhou (14.4%) to have suicidal ideation (chi2 = 45.9, P < 0.001). Female students were significantly more likely than male students to have suicidal ideation and have made suicide attempts [odds ratio (OR) = 1.4, P < 0.001]. Results indicated that the rates of suicidal ideation and suicide attempts increased with age (OR = 1.44, P < 0.001). Multivariate logistic regression models showed that suicide risk tended to decrease significantly when 'days of missed classes or school without permission were less than one', and when students thought students in their school were kind and helpful most of the time or always', 'parents or guardians checked to see if homework was done most of the time or always', 'parents or guardians understood their problems and worries most of the time or always' and 'parents or guardians really know what they are doing with their free time most of the time or always'.

CONCLUSIONS

Adolescent suicide behaviour should be a serious problem. Measures can be taken to prevent suicide by observing the factors significantly linked to suicidal behaviour. Steps can then be taken to identify adolescents who have serious suicidal ideation so that intervention can be taken to reduce the suicidal rate.

[Establishment of a rabbit model of Acanthamoeba keratitis]

AIM

To establish an animal model of Acanthamoeba keratitis.

METHODS

Six New Zealand white rabbits were each injected intrastromally with Acanthamoeba suspension 3 days after subconjunctival injection with dexamethasone.

RESULTS

All of the 6 rabbits developed keratitis. Acanthamoeba protozoa were identified by the methods of corneal scraping with 10% potassium hydroxide wet mount examined under microscope, corneal protozoa culture and pathological section examination.

CONCLUSION

A rabbit model of Acanthamoeba keratitis was established.

220 SYNERGISTIC EFFECT ON EMBRYO DEVELOPMENT BY INCLUSION OF SUPPLEMENTAL EMBRYOS IN AGAR CHIPS

The main scope of this study was to evaluate the likelihood of a helper effect of agar-embedded cleaved embryos on a low number of free embryos at a similar stage of development within the same culture droplet. Such an improved system could be beneficial within ovum pickup/in vitro embryo production (OPU/IVEP) combined protocols whenever a low number of OPU-derived cleaved embryos are produced per donor. Oocytes were recovered from abattoir ovaries, and after in vitro maturation (IVM) and in vitro fertilization (IVF), presumptive zygotes were deprived of cumulus investment and allocated into culture droplets for 24 h. At 48 h from IVF, 4- to 8-cell cleaved embryos were randomly allocated into a control and a treatment group. Control groups consisted of 1, 3, 5, and 10 embryos, respectively, in 50-μL droplets. Treatment groups consisted of 1, 3, and 5 free embryos with the addition of 9, 7, and 5 embryos, respectively, at a similar stage of development embedded in agar chips, so as to reach a total number of 10 cleaved embryos in each culture droplet. Culture was performed for both the control and treatment groups in SOF medium droplets covered with mineral oil, with the supplementation of essential and nonessential amino acids in a controlled gas atmosphere consisting of 5% CO2, 7% O2, and 88% N2 at 39°C. Final embryo output was checked at Day 7 from IVF. When considering only free embryos, the difference in progression to blastocyst development was highly significant between the control and treatment groups: 1) group 1 v. 1 + 9: 6.6 v. 84.3% (P = 0.00000); 2) group 3 v. 3 + 7: 11.1 v. 41.3% (P = 0.00001); 3) group 5 v. 5 + 5: 24.4 v. 42.2% (P = 0.00001). Rate of blastocyst development in the control group containing 10 cleaved embryos was not significantly different from free cleaved embryos in the 3 + 7 (39.2 v. 41.3%, P = 0.71) and 5 + 5 treatment groups (39.2 v. 42.2%, P = 0.54), but was significantly lower when compared with the 1 + 9 treatment group (39.2 v. 84.3%, P = 0.000). For 1, 3, 5, and 10 control group embryos, the numbers of replicates and total cleaved embryos used (n) were 30 (n = 30), 27, (n = 81), 27 (n = 135), and 39 (n = 390), respectively. For the 1 + 9, 3 + 7, and 5 + 5 treatment group embryos, the numbers of replicates and total cleaved embryos used were 32 (n = 32), 29 (n = 87), and 27 (n = 135), respectively. In conclusion, a beneficial effect of agar-embedded embryos on the development of free embryos within the same culture droplet was shown. A striking improvement in late-stage embryo development was particularly evident when considering the 1 v. 1 + 9 control and treatment groups. These results may foster a different strategic approach in in vitro culture to enhance embryo development from highly valuable donors.

Relationship between protein expression of VEGF-C, MMP-2 and lymph node metastasis in papillary thyroid cancer

Papillary thyroid cancer (PTC) is a common malignancy and has a good prognosis after appropriate treatment. PTC cells spread mainly by lymph node metastasis (LNM), but the mechanism is not well understood. Expression of vascular endothelial growth factor C (VEGF-C) and matrix metalloproteinase 2 (MMP-2) protein was studied immunohistochemically from the archived specimens of 65 PTC patients who initially presented without LNM. In this retrospective study, the frequency of expression differed significantly between thyroid cancer tissue and adjacent normal follicular epithelium (VEGF-C 78.5% and 20.0%, respectively; MMP-2 81.5% and 36.7%, respectively). LNM developed in 35 of the patients during 5 - 15 years of follow-up, by the end of which the frequencies of expression of VEGF-C and MMP-2 protein expression were 91.4% and 94.3%, respectively. Both VEGF-C and MMP-2 protein expression were significantly more frequent in PTC with LNM than without LNM. VEGF-C and MMP-2 protein expression levels were significantly correlated with LNM and it is, therefore, feasible that VEGF-C and MMP-2 may be useful as tumour markers of PTC with cervical LNM.

A novel mouse model of X-linked cardiac hypertrophy

We recovered a novel mouse mutant exhibiting neonatal lethality associated with severe fetal cardiac hypertrophy and with some adult mice dying suddenly with left ventricular hypertrophic cardiomyopathy. Using Doppler echocardiography, we screened surviving adult mice in this mutant line for cardiac hypertrophy. Cardiac dimensions were obtained either from two-dimensional images collected using a novel ECG-gated ultra-high-frequency ultrasound system or by traditional M-mode imaging on a clinical ultrasound system. These analyses identified, among the littermates, two populations of mice: those with apparent cardiac hypertrophy with hypercontractile function characterized by ejection fraction of 75–80%, and normal littermates with ejection fraction of 53–55%. Analysis of the ECG-gated two-dimensional cines indicated that the hypertrophy was of the nonobstructive type. Further analysis of heart-to-body weight ratio confirmed the ultrasound diagnosis of left ventricular hypertrophic cardiomyopathy. Histopathology showed increased ventricular wall thickness, enlarged myocyte size, and mild myofiber disarray. Ultrastructural analysis by electron microscopy revealed mitochondria hyperproliferation and dilated sarcoplasmic reticulum. Genome scanning using microsatellite DNA markers mapped the mutation to the X chromosome. DNA sequencing showed no mutations in the coding regions of several candidate genes on the X chromosome, including several known to be associated with left ventricular hypertrophic cardiomyopathy. These findings suggest that this mouse line may harbor a mutation in a novel gene causing X-linked cardiomyopathy.

Removal of FKBP12.6 does not alter the conductance and activation of the cardiac ryanodine receptor or the susceptibility to stress-induced ventricular arrhythmias

The 12.6-kDa FK506-binding protein (FKBP12.6) is considered to be a key regulator of the cardiac ryanodine receptor (RyR2), but its precise role in RyR2 function is complex and controversial. In the present study we investigated the impact of FKBP12.6 removal on the properties of the RyR2 channel and the propensity for spontaneous Ca(2+) release and the occurrence of ventricular arrhythmias. Single channel recordings in lipid bilayers showed that FK506 treatment of recombinant RyR2 co-expressed with or without FKBP12.6 or native canine RyR2 did not induce long-lived subconductance states. [(3)H]Ryanodine binding studies revealed that coexpression with or without FKBP12.6 or treatment with or without FK506 did not alter the sensitivity of RyR2 to activation by Ca(2+) or caffeine. Furthermore, single cell Ca(2+) imaging analyses demonstrated that HEK293 cells co-expressing RyR2 and FKBP12.6 or expressing RyR2 alone displayed the same propensity for spontaneous Ca(2+) release or store overload-induced Ca(2+) release (SOICR). FK506 increased the amplitude and decreased the frequency of SOICR in HEK293 cells expressing RyR2 with or without FKBP12.6, indicating that the action of FK506 on SOICR is independent of FKBP12.6. As with recombinant RyR2, the conductance and ligand-gating properties of single RyR2 channels from FKBP12.6-null mice were indistinguishable from those of single wild type channels. Moreover, FKBP12.6-null mice did not exhibit enhanced susceptibility to stress-induced ventricular arrhythmias, in contrast to previous reports. Collectively, our results demonstrate that the loss of FKBP12.6 has no significant effect on the conduction and activation of RyR2 or the propensity for spontaneous Ca(2+) release and stress-induced ventricular arrhythmias.

Functional consequence of protein kinase A-dependent phosphorylation of the cardiac ryanodine receptor: sensitization of store overload-induced Ca2+ release

The phosphorylation of the cardiac Ca(2+)-release channel (ryanodine receptor, RyR2) by protein kinase A (PKA) has been extensively characterized, but its functional consequence remains poorly defined and controversial. We have previously shown that RyR2 is phosphorylated by PKA at two major sites, serine 2,030 and serine 2,808, of which Ser-2,030 is the major PKA site responding to beta-adrenergic stimulation. Here we investigated the effect of the phosphorylation of RyR2 by PKA on the properties of single channels and on spontaneous Ca(2+) release during sarcoplasmic reticulum Ca(2+) overload, a process we have referred to as store overload-induced Ca(2+) release (SOICR). We found that PKA activated single RyR2 channels in the presence, but not in the absence, of luminal Ca(2+). On the other hand, PKA had no marked effect on the sensitivity of the RyR2 channel to activation by cytosolic Ca(2+). Importantly, the S2030A mutation, but not mutations of Ser-2,808, diminished the effect of PKA on RyR2. Furthermore, a phosphomimetic mutation, S2030D, potentiated the response of RyR2 to luminal Ca(2+) and enhanced the propensity for SOICR in HEK293 cells. In intact rat ventricular myocytes, the activation of PKA by isoproterenol reduced the amplitude and increased the frequency of SOICR. Confocal line-scanning fluorescence microscopy further revealed that the activation of PKA by isoproterenol increased the rate of Ca(2+) release and the propagation velocity of spontaneous Ca(2+) waves, despite reduced wave amplitude and resting cytosolic Ca(2+). Collectively, our data indicate that PKA-dependent phosphorylation enhances the response of RyR2 to luminal Ca(2+) and reduces the threshold for SOICR and that this effect of PKA is largely mediated by phosphorylation at Ser-2,030.

Receptor-mediated internalization of chelator-PNA-peptide hybridization probes for radioimaging or magnetic resonance imaging of oncogene mRNAs in tumours

Early external detection of cancer gene activity might enable early treatment of cancer and might reduce cancer mortality. We hypothesized that oncogene mRNA overexpressed at thousands of copies per malignant cell in a zone of transformed cells could be imaged externally by scintigraphic imaging, PET (positron emission tomography) or MRI (magnetic resonance imaging) with PNA (peptide nucleic acid) hybridization probes that include chelators for metal cations and a cyclized peptide analogue of IGF-1 (insulin-like growth factor 1), D(Cys-Ser-Lys-Cys), to mediate internalization by IGF1R (IGF-1 receptor) overexpressed on cancer cells. We observed that human MCF7 breast cancer cells that overexpress IGF1R efficiently internalized fluorescein-chelator-PNA-D(Cys-Ser-Lys-Cys) to the cytoplasm, but not with D(Cys-Ala-Ala-Cys). Scintigraphic imaging of MCF7 xenografts in immunocompromised mice revealed that CCND1 and MYC [(99m)Tc]chelator-PNA-D(Cys-Ser-Lys-Cys) probes yielded xenograft. PET imaging with [(64)Cu]chelator-PNA-D(Cys-Ser-Lys-Cys) yielded stronger signals. Scintigraphic imaging of human AsPC1 pancreas cancer xenografts with [(99m)Tc]chelator-KRAS PNA-D(Cys-Ser-Lys-Cys) yielded strong xenograft signals. Stronger xenograft image intensities were obtained by PET imaging of [(64)Cu]chelator-KRAS PNA-D(Cys-Ser-Lys-Cys). MRI required extension of chelator-polydiamidopropanoate dendrimers from the N-termini of the PNA probes to increase the number of contrast paramagnetic gadolinium (III) cations per probe. These results provide a basis for detection of oncogene activity in tissues from outside the body by hybridization with metal-chelator-PNA-peptides that are selectively internalized by cancer cells.

Hormonal treatments for increasing the oocyte and embryo production in an OPU–IVP system

The objective was to enhance the inherent developmental ability of bovine oocytes retrieved by ultrasound-guided transvaginal aspiration. Various hormonal regimes were utilized to produce partially matured oocytes in vivo, in order to improve embryo development following IVF. In the first experiment, a two-by-two factorial design was used with FSH (multiple versus single dose) and im administration of LH (yes versus no) 6h prior to OPU. In all protocols (which lasted for nine consecutive weeks), ovarian stimulation was performed in the presence of a CIDR. One FSH administration was adequate for ovarian stimulation (9.33+/-0.7 and 10.14+/-0.7 follicles per cow per OPU session); however, multiple injections increased (P<0.05) follicular response (12.97+/-0.7 and 13.97+/-0.7). In the second experiment, a two-by-two factorial design was used to compare the effects, during ovarian stimulation, of the presence or absence of CIDR, and iv treatment with LH 6h prior to OPU (yes versus no), on oocyte competence (judged by blastocyst development rates following IVF). Presence of CIDR during superstimulation had no effect on the follicular response. Administration of LH 6h prior to OPU increased (P<0.05) the oocytes of higher morphological grades, and in the absence of a CIDR, improved (P<0.05) blastocyst development rate. Treatment with LH, 6h prior to OPU without the use of CIDR during ovarian stimulation, resulted in 2.89+/-0.4 blastocysts per cow per OPU session as compared to 1.56+/-0.4, 1.56+/-0.4 and 1.33+/-0.4 for all other groups. In conclusion, compared to single administration, multiple FSH administration increased (P<0.05) available follicles for aspiration. Moreover, when ovarian stimulation in the absence of CIDR was followed by administration of LH 6h prior to OPU, it increased (P<0.05) the number of blastocysts per OPU session.

Single-trial extraction of cognitive evoked potentials by combination of third-order correlation and wavelet denoising

The application of a recently proposed denoising implementation for obtaining cognitive evoked potentials (CEPs) at the single-trial level is shown. The aim of this investigation is to develop the technique of extracting CEPs by combining both the third-order correlation and the wavelet denoising methods. First, the noisy CEPs was passed through a finite impulse response filter whose impulse response is matched with the shape of the noise-free signal. It was shown that it is possible to estimate the filter impulse response on basis of a select third-order correlation slice (TOCS) of the input noisy CEPs. Second, the output from the third-order correlation filter is decomposed with bi-orthogonal splines at 5 levels. The CEPs is reconstructed by wavelet final approximation a<inf>5</inf>. We study its performance in simulated data as well as in cognitive evoked potentials of normal rat and Alzheimer's disease (AD) model rat. For the simulated data, the method gives a significantly better reconstruction of the single-trial cognitive evoked potentials responses in comparison with the simulated data. Moreover, with this approach we obtain a significantly better estimation of the amplitudes and latencies of the simulated CEPs. For the real data, the method clearly improves the visualization of single-trial CEPs. This allows the calculation of better averages as well as the study of systematic or unsystematic variations between trials.

Chaotic Dynamics in Tracing BAEP and its Application on Investigating Brainstem Malfunction

The purpose of this study is to investigate the chaotic dynamics of tracing (dynamic) brainstem auditory evoked potential (BAEP), then to investigate the brainstem malfunction via dynamic characteristics of tracing BAEP. The radial basis function neural network (RBFNN) technique in combination with the moving window average (MWA) method was employed in order to extract the tracing BAEP from strong noise background. Data of noisy BAEP were collected from the Infantile spasm (IS) group with brainstem malfunction and the tester group respectively. The chaotic dynamics of tracing BAEP were analyzed using phase projection and correlation dimension techniques. The results of this study have demonstrated: (1) there is a much stronger determination in BAEP than in noisy BAEP shown by more deterministic phase projections and lower D<inf>2</inf>in BAEP; (2) trajectories of BAEP never repeat and the value of correlation dimension is fractal; (3) the phase projection of BAEP for brainstem malfunction group shows more chaotic and has higher D<inf>2</inf>than those for the tester group. The conclusions of this investigation suggest that BAEP is chaotic not deterministic and there is rich dynamics in BAEP; tracing BAEP is much more useful than noisy BAEP in describing brainstem malfunction because BAEP shows determination corresponding to brainstem function; BAEP in brainstem malfunction has more non-order dynamics than that in the tester.

A Simulation Study of Firing Patterns based on Coupling Effect between Soma and Dendrite

The aim of this study is to investigate how firing patterns of neuron in hippocampus change with coupling effect between soma and dendrite via simulation of single neuron firings by a two-compartment (soma-dendrite) model. The results will help to understand how firing patterns relative to synaptic plasticity in further study. The neuron model used in this study consisted two compartments: the soma compartment and the dendrite compartment, which can describe synaptic input functions. Simulations of neural firings were performed with fourth order Runge-Kutta algorithm with different range of coupling conductance. Firing patterns of neuron were simulated under different current applied to soma (Is). The range for different firing patterns is: Is=0..A/cm2, range for spiking is [0.0, 1.8] and [4.5, ..], for bursting is [1.9,4.4]; Is=0.5..A/cm2, range for spiking is [0.0, 2.2] and [4.0, ..], for bursting is [2.3,3.9]; Is=1.0..A/cm2, range for spiking is [0.0, 2.5] and [3.6, ..], for bursting is [2.6,3.5]; Is=1.5..A/cm2, range for spiking is [0.0, 2.5] and [3.8, ..], for bursting is [2.6,3.7]; Is=2.0..A/cm2, range for spiking is [0.0, 2.6] and [3.6, ..], for bursting is [2.7,3.5]; Is=2.5..A/cm2, range for spiking is [0.0, 2.6] and [3.3, ..], for bursting is [2.7,3.2].

346 BOVINE EMBRYO DEVELOPMENT AFTER IVM/IVF/IVC OF OOCYTES STORED FOR 22 H IN VARIOUS MEDIA

The timing of IVM–IVF–IVC is restricted by the onset of oocyte maturation, and sometimes oocytes must be treated at midnight. If we could regulate the timing of IVM of oocytes without decreasing their developmental competence, the IVM–IVF–IVC system could be a more applied technology. The present study was performed to examine the effects of in vitro storage of bovine oocytes in simple media prior to maturation culture to manipulate the start of IVM. Bovine follicular fluid (bFF), Dulbecco&apos;s PBS (PBS), M199 Earle salts (M199), and Earle salts supplemented with 5 mM NaHCO3 (M199A) were used as the fundamental media, after an addition of antibiotics, for in vitro storage of bovine cumulus&ndash;oocyte complexes (COCs) collected from ovaries obtained at the slaughterhouse. The fundamental media except for bFF were supplemented with 10&percnt; fetal bovine serum (FBS) or 1 mg mL&minus;1 polyvinyl alcohol (PVA). COCs were collected from follicles (3&ndash;8 mm in diameter) and washed twice in each medium; then approximately 50 COCs were submerged in 1 mL of each medium in cryotubes (Falcon #2812, 2.5 mL; Becton Dickinson Labware, Lincoln, NJ, USA), which were stored in a container kept at 38.5&deg;C for 22 h under air-closed condition (in vitro storage: IVS). Subsequently, the stored COCs were in vitro-matured (IVM) for 22 h in M199 with 10&percnt; FBS and 20 &micro;g mL&minus;1 estradiol, fertilized (IVF), and cultured in CR1aa (IVC) for examination of their development to the blastocyst stage (Kubota et al. 1998 Mol. Reprod. Dev. 51, 281&ndash;286). Fresh oocytes without IVS were used as controls. The nuclear status of oocytes after IVS&ndash;IVM was compared to that of control oocytes by aceto-orcein stain. Their developmental rates to the blastocyst stage after IVM&ndash;IVF&ndash;IVC were compared between experimental and control groups. The experiment was repeated more than 3 times, and results were statistically analyzed using Student&apos;s t-test. When bFF and PBS supplemented with FBS or PVA were used for IVS, the rates of survived COCs after IVS and the development to the blastocyst stage after IVM&ndash;IVF&ndash;IVC (bFF (n &equals; 87): 0&percnt;, 0&percnt;; PBS/FBS (n &equals; 72): 84&percnt;, 1&percnt;; and PBS/PVA (n &equals; 81): 89&percnt;, 6&percnt;, respectively) were significantly lower than those of the control group (n &equals; 406; 97&percnt; and 29&percnt;, respectively). On the other hand, when M199A supplemented with FBS or PVA was used for IVS, the survival rate after IVS and the developmental rate to the blastocyst stage after IVS&ndash;IVM&ndash;IVF (M199A/FBS (n &equals; 97): 82&percnt;, 28&percnt;; and M199A/PVA (n &equals; 111): 98&percnt;, 31&percnt;, respectively) did not differ from those of the control group. After IVS, cumulus expansion was not seen and most of the oocyte nuclei reached the GVBD stage. These results suggest that the nuclear maturation progress of bovine oocytes can be regulated for at least 22 h in M199A without any deleterious influence on the number of oocytes surviving at an immature state after the storage and their subsequent development to the blastocyst stage after IVM&ndash;IVF&ndash;IVC. The delayed maturation allows a flexible fertilization schedule which is advantageous in research and industrial applications.

96 TRICHOSTATIN A IMPROVED THE QUALITY OF RABBIT NUCLEAR TRANSFER EMBRYOS

Nuclear reprogramming is dependent upon a number of factors, including chromatin organization and modification. Trychostatin A (TSA), a histone deacetylase inhibitor, was used to increase histone acetylation and to improve reprogrammability in both cattle and mice. The objective of the study was to determine whether TSA could improve the pre-implantational development potential of rabbit nuclear transplant (NT) embryos. Rabbit oocytes were flushed from the oviducts of superovulated donors treated with the regime of FSH and hCG. Cumulus cells were then denuded from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in 10% FBS M199 and confirmed under fluorescence microscopy. Cumulus cells were prepared as nuclear donors for NT; a donor cell with the diameter approximately 15–19 µm was transferred into the perivitelline space of an enucleated oocyte, and subsequently fused with the oocyte recipient by application of 3 direct current pulses at 3.2 kV cm−1 for a duration of 20 µs/pulse. Fused embryos were activated by the same electrical stimulation regime described above, and subsequently cultured in M199 + 10% FBS containing 2.0 mM 6-dimethylaminopurine (DMAP) and 5 µg mL−1 cycloheximide for 1 h. Rabbit NT embryos were cultured in 5 nM TSA-2.5% FBS-B2 medium for 10 h before being transferred into regular medium (FBS-B2). The TSA-treated embryos (5 nM vs. 0 nM) were cultured in 400 µL FBS-B2 medium for 5 days in 5% CO2 in a humidified atmosphere at 38.5°C (initiation of activation = Day 0). NT embryo development to cleaved (2 to 4 cell), morula, and blastocyst stages was evaluated on Day 2, Day 3, and Day 5, respectively. The selected NT blastocysts were counted for cell numbers following Hoechst 33342 epifluorescenin staining. The results (Table 1) showed that there was no difference on pre-implantational development of cloned embryos between TSA-added and control groups (P &gt; 0.05). However, a significantly higher cell number per NT blastocyst was found in the TSA-added group (357 vs. 113; P &lt; 0.05). This indicated that the blastocyst quality in NT embryos was improved with the addition of TSA by increasing histone acetylation activity. The developmental potential of TSA-treated NT embryos to term is under investigation. Table 1.Effects of TSA on the pre-implantational development of cloned rabbit embryos This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261-01.

Livin promotes Smac/DIABLO degradation by ubiquitin-proteasome pathway

Livin, a member of the inhibitor of apoptosis protein (IAP) family, encodes a protein containing a single baculoviral IAP repeat (BIR) domain and a COOH-terminal RING finger domain. It has been reported that Livin directly interacts with caspase-3 and -7 in vitro and caspase-9 in vivo via its BIR domain and is negatively regulated by Smac/DIABLO. Nonetheless, the detailed mechanism underlying its antiapoptotic function has not yet been fully characterized. In this report, we provide, for the first time, the evidence that Livin can act as an E3 ubiquitin ligase for targeting the degradation of Smac/DIABLO. Both BIR domain and RING finger domain of Livin are required for this degradation in vitro and in vivo. We also demonstrate that Livin is an unstable protein with a half-life of less than 4 h in living cells. The RING domain of Livin promotes its auto-ubiquitination, whereas the BIR domain is likely to display degradation-inhibitory activity. Mutation in the Livin BIR domain greatly enhances its instability and nullifies its binding to Smac/DIABLO, resulting in a reduced antiapoptosis inhibition. Our findings provide a novel function of Livin: it exhibits E3 ubiquitin ligase activity to degrade the pivotal apoptotic regulator Smac/DIABLO through the ubiquitin-proteasome pathway.

Comparison of different transvaginal ovum pick-up protocols to optimise oocyte retrieval and embryo production over a 10-week period in cows

The objective was to develop a simple and effective ovum pick-up (OPU) protocol for cows, optimised for oocyte harvest and subsequent in vitro embryo production (IVP). Five protocols differing in collection frequency, dominant follicle removal (DFR) and FSH stimulation were tested on groups of three cows each, over an interval of 10 consecutive weeks. Performance was evaluated on per OPU session, per week and pooled (3 cowsx10weeks) basis. Among the non-stimulated groups, on a per cow per session basis, once- or twice-weekly OPU had no effect on the mean (+/- S.E.M.) number of follicles aspirated, oocytes retrieved and blastocysts produced (0.6+/-0.8 and 0.7 +/- 0.7, respectively). However, DFR 72 h prior to OPU almost doubled blastocyst production (1.2 +/- 1.3). In stimulated groups, FSH treatment (80 mg IM and 120 mg SC) was given once weekly prior to OPU. Treatment with FSH, followed by twice-weekly OPU, failed to show any synergistic effect of FSH and increased aspiration frequency. When FSH was given 36 h after DFR, followed by OPU 48 h later, more (P < 0.05) follicles (16.0 +/- 5.0), oocytes (10.6 +/- 4.5) and embryos (2.1 +/- 1.2) were obtained during each session, but not on a weekly basis. Pooled results over 10 weeks showed an overall improved performance for the treatment groups with twice-weekly OPU sessions, due to double the number of OPU sessions performed. However, the protocol that consisted of DFR, FSH treatment and a subsequent single OPU per week, was the most productive and cost-effective, with potential commercial appeal.

Four-wave mixing assisted self-stable 4x10 GHz actively mode-locked Erbium fiber ring laser

We proposed and developed a self-stable multiwavelength (4 cbannels) 10-GHz actively mode-locked Erbium-doped fiber ring laser with 0.8 nm wavelength spacing. A 1-km highly nonlinear fiber is incorporated in the laser cavity to eliminate the strong gain competitions in the homogeneously broadened EDF by multiple parametric four-wave mixing processes. The fiber nonlinearity is also helpful to provide phase locking and stabilize the output pulse. Stable laser pulses at 1556.55, 1557.36, 1558.17, and 1558.98 nm are successfully obtained simultaneously with supermode noise suppression ratio greater than 50 dB. The corresponding time-bandwidth products of four channels are 0.39 ~ 0.41.

31 FULL-TERM AND LIVE RABBIT CLONES PRODUCED BY SOMATIC CELL NUCLEAR TRANSFER

Transgenic/knockout (KO) rabbits can serve as an excellent animal model for human cardiovascular diseases (CVD) and other diseases. However, the production of transgenic/KO rabbits is hindered by low efficiency of traditional DNA microinjection and the unavailability of embryonic stem cell lines. An alternative approach is to produce transgenic/KO rabbits by somatic cell nuclear transfer (SCNT) using genetically modified somatic cells as nuclear donors. Our initial objective of the study was to prove the feasibility of cloning rabbits by SCNT because rabbit is a difficult species to be cloned. Rabbit oocytes were flushed from the oviducts of superovulated donors treated with the regime of follicle-stimulating hormone (FSH) and human choriani gonadotropin (hCG). Cumulus cells were then denuded from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in M199 + 10% fetal bovine serum (FBS) and confirmed by fluorescence microscopy. Cumulus cells used for nuclear donors were prepared from fresh cumulus-oocytes complexes. The donor nucleus was transferred into a recipient oocyte by either cell fusion or direct nuclear injection method. In the cell fusion method, a small donor cell with the diameter approximately 15–19 µm was transferred into the perivitelline space of an enucleated oocyte; subsequently the somatic cell-cytoplast pair was fused by applying three direct current pulses at 3.2 kV/cm for a duration of 20 µs/pulse. In the direct nuclear injection method, a mechanically lysed donor cell was injected into oocyte cytoplasm with the aid of a piezo-drill system. Fused embryos or injected oocytes were activated by the same electrical stimulation regime described above, and subsequently cultured in M199 + 10% FBS containing 2.0 mM 6-dimethylaminopurine (DMAP) and 5 µg/mL cycloheximide for 2 h. For the in vitro study, cloned embryos were cultured in B2 medium plus 2.5% FBS for 5 days (initiation of activation = day 0) at 38.5°C in 5% CO2 humidified air. For the in vivo study, cloned embryos were cultured for 20–22 h in vitro before transfer into pseudopregnant rabbit recipients. Pregnancy was monitored by palpation and/or ultrasound on Days 14–16 post embryo transfer (ET). The results (Table 1) show that the donor nuclei-introducing rate was higher with nuclear direct injection than with the cell fusion method (P < 0.05). There were no significant differences among subsequent cleavage and development to morula and blastocysts between both methods, although the development rates of cloned embryos via electrically mediated fusion were higher than those derived from the injection group. One recipient in the injection group (1/6, 17%) and six recipients in the fusion group (6/16, 38%) were diagnosed as pregnant. From the fusion group, one full-term but stillborn and one live and healthy clone rabbit were delivered on Days 33 and 31 post-ET, respectively. To our knowledge, this is the second report of full term development of cloned rabbit by somatic nuclear transfer cloning. Our further study is to clone live rabbit offspring with modified transgenic/KO somatic cell lines. Table 1. In vitro development of rabbit cloned embryos with cumulus cells as nuclear donors This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261–11.

Tumor-targeting peptide-PNA-peptide chimeras for imaging overexpressed oncogene mRNAs

We have optimized a method involving continuous solid phase synthesis of chelator-peptide-PNA-peptide probes in order to noninvasively image oncogene mRNAs overexpressed in tumors. The PNA (peptide nucleic acid) probes carry cyclized peptide ligand analogs specific for receptors overexpressed on malignant breast or colorectal cancer cells, and chelators to bind radioactive metal ions, or a fluorophore. In vivo scintigraphic imaging of MCF7 xenografts in immunocompromised mice indicated that CCND1 and MYC [99sTc] chelator-PNA-D (CSKC) probes concentrated in MCF7 cells up to 7 times more than the corresponding mismatch controls.

Coadministration of Interleukin 2 Plasmid DNA with Combined DNA Vaccines Significantly Enhances the Protective Efficacy AgainstMycobacterium tuberculosis

Coadministration of interleukin 2(IL-2) plasmid DNA with combined DNA vaccines enhanced Th1-type cellular responses by producing higher amounts of IFN-gamma with a higher ratio of antigen-specific IgG2a/IgG1. The IFN-gamma specific for Ag85B, MPT64, and MPT83 in this group was 415, 267, and 255 U/ml, respectively, and was 1.6-, 1.8-, and 2.5-fold higher than that of the same vaccine without adding IL-2. The IgG2a/IgG1 ratio for Ag85B, MPT64, and MPT83 was 4, 8, and 4, respectively, upon addition of the genetic adjuvant in the DNA vaccine, which was four times higher for every antigen when IL-2 was not included. Fluorescence activated cell sorter (FACS) analysis showed that, in the presence of IL-2, CD8+ and CD4+ T cells increased significantly, whereas in the absence of the genetic adjuvant, only a mild increase was observed for CD8+ T cells compared to the vector DNA-treated group. Bacterial CFU was reduced to less than 1/100 in the lung and to about 1/10 in the spleen relative to the same combined DNA vaccine without IL-2. The lungs of this group of mice showed much less damage due to an influx of epithelioid macrophages and less lymphocytes. RT-PCR showed that antigen genes could be detected in more organs and for a longer period of time when treated with combined DNA vaccine formulated in IL-2. We suggest that IL-2 enhanced the immunigencity and protective efficacy in immunized mice by improving the Th1-type response and also by prolonging the antigen gene expression in different organs.

Combined DNA vaccine encapsulated in microspheres enhanced protection efficacy against Mycobacterium tuberculosis infection of mice

In a study to develop novel vaccination strategies against tuberculosis, we encapsulated DNA encoding Ag85B, MPT-64 and MPT-83 antigens mixed with dimethyldioctyldecyl ammonium bromide (DDA) into biodegradable poly(dl-lactide-co-glycolide, PLGA) microspheres. Scanning electron microscopy (SEM) analysis demonstrated a uniform microsphere population with a mean diameter of <5microm. Using RT-PCR we were able to demonstrate antigen gene expression in selected tissue. Moreover, in mice injected with PLGA encapsulated DNA, the levels of expression appeared to be higher comparing to those injected with non-encapsulated DNA. Also, C57BL/6 mice immunized with a single dose of PLGA encapsulated DNA produced increased levels of IFN-gamma in the supernatant of spleen cells when cultured in the presence of the recombinant antigens. High levels of specific IgG antibody against the three antigens were also observed. In vaccine/challenge experiments, mice receiving a single dose of PLGA encapsulated DNA were protected against Mycobacterium tuberculosis challenge at levels comparable to groups of mice immunized with three doses of non-encapsulated DNA vaccine or with Mycobacterium bovis BCG.

Information theory in prediction of cleavage sites of signal peptides

Information theory is used to analyze the character of signal peptide quantitatively, especially residents. On the basis of the above analysis, a method named simplified information-matrix has been developed to predict the cleavage sites of signal peptides. A comparison between the results of weight-matrix and simplified information-matrix is presented.

Combined DNA vaccines formulated either in DDA or in saline protect cattle from Mycobacterium bovis infection

We tested the effectiveness of combined DNA vaccines encoding antigens Ag85B, MPT64 and MPT83 from Mycobacterium tuberculosis on cattle. Our results showed that calves treated with combined DNA vaccines in the presence of dimethyldioctyldecyl ammonium bromide (DDA) or saline elicited a strong gamma interferon (IFN-gamma) response 1 or 2 months after the third vaccination. All three antigens induced substantial levels of IFN-gamma production 1 month after the bacterial challenge, when the BCG-driven IFN-gamma levels dropped to less than one third of their peak values. Animals receiving combined DNA vaccines produced highest amounts of IgG antibody titer 2 months after the third vaccination. Steady state low IgG levels were found 2 months after bacterial challenge. A few small lung and lymph node lesions were detected in 1/5 animals treated with combined DNA vaccines, whereas 3/5 of BCG-treated and 5/5 of vector-control calves showed larger and significantly more lesions. About 70- to 100-fold fewer bacteria were found in the lungs and lymph nodes of combined DNA vaccine-treated animals compared to those of the control group. Histopathological analyses showed that vaccinated calves possessed substantially improved post-infection lung and lymph node pathology relative to the controls. Our data indicate that combined DNA vaccines may be used in cattle to combat bovine tuberculosis.

Sequence specificity of alternating hydroyprolyl/phosphono peptide nucleic acids against zebrafish embryo mRNAs

Morpholino phosphorodiamidate (MO) DNA mimics display excellent water solubility and hybridization properties toward DNA and RNA, and have been utilized in the model vertebrate zebrafish (Danio rerio) for genome-wide, sequence-based, reverse genetic screens during embryonic development. Peptide nucleic acids (PNAs) exhibit excellent mismatch discrimination, nuclease resistance, and protease resistance, but low solubility. Negatively charged DNA mimics composed of alternating residues of trans-4-hydroxy-L-proline peptide nucleic acid monomers and phosphono peptide nucleic acid monomers (HypNA-pPNA) combine all of the positive features of both MOs and PNAs. Thus, we evaluated PNA oligomers and HypNA-pPNA oligomers as an alternative to MOs for oligonucleotide inhibition of gene expression in zebrafish embryos. We observed that HypNA-pPNA 18-mers displayed comparable potency to MO 25-mers as knockdown agents against chordin, notail and uroD, with greater mismatch stringency. Furthermore, we observed that a specific HypNA-pPNA 18-mer elicited the dharma (bozozok)(-/-) phenotype in zebrafish embryos, which MO 25-mers do not. These observations validate HypNA-pPNAs as an alternative to MO oligomers for reverse genetic studies. The stronger hybridization and greater specificity of HypNA-pPNAs enable knockdown of mRNAs unaffected by MO oligomers.

Transmembrane serine protease TADG-15 (ST14/Matriptase/MT-SP1): expression and prognostic value in ovarian cancer

Tumour-associated differentially expressed gene-15 (TADG-15/ST14/matriptase/MT-SP1) is a novel member of the transmembrane serine proteases. Previous studies indicated that TADG-15 is overexpressed in ovarian tumours; however, relationships between expression of TADG-15 and clinical characteristics of ovarian cancer remain unclear. The purpose of this study was to examine TADG-15 expression in ovarian cancers and determine any associations with clinicopathological characteristics or patient survival. Immunohistochemical study revealed that TADG-15 was expressed in 50 (56.2%) of 89 ovarian carcinomas, whereas it was not detected in normal ovaries. TADG-15 expression was significantly more common in patients with early stage disease compared with patients with advanced stage diseases (namely, stage I, 24 out of 33: 72.7%; stage II/III/IV, 26 out of 56: 46.4%; P=0.0157). Kaplan–Meier survival curves demonstrated that patients with TADG-15-positive tumours have had substantially longer survival (P=0.0480). The mean value of relative TADG-15 mRNA expression ratio was significantly higher in stage I tumours than in stage II/III/IV tumours (P=0.0053). Increased expression of TADG-15 is frequently detected in early stage cancers, with expression level downregulated during progression of disease. TADG-15 is associated with early stage ovarian cancer and longer patient survival; therefore, it may be a favourable prognostic marker for this malignancy.

Combined DNA Vaccines Formulated in DDA Enhance Protective Immunity against Tuberculosis

This study evaluated the adjuvant Dimethyldioctyldecyl Ammonium Bromide (DDA) effect on the protective immunity induced by a combination of plasmids containing genes encoding antigens Ag85B, MPT-83, and ESAT-6 from Mycobacterium tuberculosis. The combined DNA vaccines in DDA resulted in significant increases in both specific IgG and splenic T-cell-derived Th1-type cytokine gamma interferon (IFN-gamma) production in response to the three purified antigens when compared to that of combined DNA vaccines in saline. Vaccines in DDA increased the protective efficacy of mice challenged with M. tuberculosis H37Rv as measured by reduced relative CFU counts in their lungs. Mice immunized with the combined DNA vaccines were shown to limit the growth of tubercle bacilli both in lungs and in spleens. Histopathological analyses showed that vaccinated mice had substantially improved postinfection lung pathology relative to the controls. We suggest that our combination of antigens together with DDA formulation may provide a new insight into tuberculosis prevention.

261DIFFERENT TRANSVAGINAL OVUM PICK-UP STRATEGIES TO OPTIMIZE THE OOCYTE RETRIEVAL AND EMBRYO PRODUCTION OVER A FIXED PERIOD OF TIME

The objective of this study was to compare the efficacy of different oocyte retrieval schemes over a period of 10 weeks. Fifteen multiparous Angus cows were randomly assigned (n=3/group) to the following groups: 1) OPU once/week (7-day interval), 2) OPU twice/week (3- and 4-day interval, alternately), 3) Dominant follicle removal (DFR)+OPU once/week. DFR followed by OPU 72h later, 4) DFR+FSH+OPU once/week. DFR followed 36h later by FSH (Folltropin, Bioniche, Belleville, Ontario, Canada) (120mg s.c. and 80mg i.m. administered simultaneously) followed by OPU 48h later, 5) FSH+OPU twice/week. FSH followed by OPU1 30h later and OPU2 96h after OPU1. The interval between OPU2 and next FSH was approximately 42h. The follicles were aspirated using an Aloka ultrasound scanner (Wallingford, CT, USA) and a 5-MHz probe. The COCs were selected based on morphology and matured in TCM-199, supplemented with 10% FCS, 0.01 unitsmL−1 bFSH, 0.01 unitsmL−1 bLH and antibiotics. Fertilization (Day 0) was carried out with TALP-FERT medium containing capacitation factors. Frozen semen from the same bull was used (1×106mL−1) throughout. After 18h the presumptive zygotes were cultured in SOF with 5% FCS (Holm P et al., 1999 Theriogenology 52, 683–700). The embryos were evaluated based on IETS guidelines (Grades 1 and 2 selected). The data were analyzed by chi-square test and ANOVA. In all parameters, the DFR followed by FSH and subsequent OPU once/week protocol gave the best results on a per-cow-per-week as well as total (3 cows over 10 weeks) basis. Though OPU was done only once/week, this group produced more total oocytes (303) than groups where OPU was done twice/week, either with FSH (286) or without FSH (229) and also produced more total embryos on Day 8 (71 blastocysts, 23.4% of oocytes cultured) than the latter two groups (64, 22.4% and 49, 21.4%, respectively). Among the nonstimulated groups, the OPU twice/week group had more total oocytes (236) than groups with OPU once/week, either without DFR (137) or with preceding DFR (160). However, a preceding DFR seemed to have a positive effect on oocyte quality as this group had a better embryo development rate (26.9%), producing more total embryos (42). In comparison, OPU twice/week produced total 49 embryos (21.4%) and OPU once/week produced 26 (19.4%). In conclusion, DFR coupled with single-shot FSH administration can be used effectively over a period of at least 10 consecutive weeks and can increase (P&lt;0.05) the oocyte yield by two-fold and embryo production following IVF by two and half-fold, as compared to routine OPU-IVF done once a week. Table 1 Per cow per week performance

99mTc-peptide-peptide nucleic acid probes for imaging oncogene mRNAs in tumours

Imaging oncogene mRNA in tumours would provide a powerful tool for the early detection of occult malignant lesions. The goal was to prepare a chimera consisting of a dodecamer antisense peptide nucleic acid (PNA) specific for c-MYC oncogene overexpressed in human breast cancer cells and a chelating moiety that facilitates quantitative radiolabelling with 99mTc and evaluate it for hybridization and tissue distribution in laboratory animals. The pentapeptide chelator-PNA dodecamer specific for c-MYC mRNA was extended from a solid support by 9-fluorenylmethyloxycarbonyl (Fmoc) coupling. Similarly, a chelator-PNA chimera with four central mismatches was also prepared which served as a control. The chimeras were purified, characterized and evaluated for hybridization to c-MYC mRNA by fluorescent, real-time polymerase chain reaction (RT-PCR). The chimeras were labelled with 99mTc and their tissue distribution was examined in athymic nude mice bearing experimental human breast tumours. 99mTc radiolabelling was quantitative and presented a single peak in reversed phase liquid chromatography. Fluorescent real-time polymerase chain reactions using primer and fluorescent probe sets previously calculated for c-MYC mRNA demonstrated inhibition of reverse transcription by the c-MYC specific chimera as compared to that of the control. Tissue distribution studies of antisense and mismatch chimeras at 4 h and 24 h after administration displayed modest accumulation in the liver, and appreciable levels in tumours. These observations suggest that 99mTc-peptide-PNA probes might be useful for imaging gene expression in tumours, and the approach is worthy of further investigation.

Expression of Plasmodium falciparum-infected erythrocyte membrane protein from cerebral malaria patients

AIM

To provide theoretical evidence for studying the molecular pathogenesis of human cerebral malaria.

METHODS

The expressions of Plasmodium falciparum erythrocyte membrane protein 1(PfEMP1) on the surface of parasitized erythrocyte (PE) specimens from 19 cases of cerebral malaria patients in Yunnan Province were quantitatively analyzed by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique. 43 patients of falciparum malaria, 9 patients of vivax malaria and 6 healthy controls were also investigated.

RESULTS

The expressions of higher molecular mass (Mr) 260-320 kDa forms of PfEMP1 were found on PE from cerebral malaria patients. By contrast, the expression of PfEMP1 and P. vivax erythrocyte membrane protein (PvEMP1) on PE from falciparum malaria patients and vivax malaria patients had a PfEMP1 with Mr 240 kDa and a PvEMP1 with Mr 180 kDa band, respectively. Healthy controls expressed an EMP of Mr 140 kDa.

CONCLUSION

The binding of 260-320 kDa PfEMP1 proteins expressed on PE from cerebral malaria patients to diverse receptor molecules on the endothelial cell(EC) of the cerebral microvessels such as CD36, thrombospondin (TSP), intercellular adhesion molecule 1(ICAM-1), vascular cell adhesion molecule 1(VCAM-1), endothelial leukocyte adhesion molecule 1(ELAM-1) and chondroitin sulfate A (CSA) might be the molecular basis for the pathogenesis of cerebral malaria.

Ultrastructural observations on the formation and metabolism of calcareous corpuscles in Cysticercus cellulosae

AIM

To study the formation and metabolism of calcareous corpuscles from Cysticercus cellulosae at the ultrastructure level.

METHODS

Transmission electron microscopy.

RESULTS

The developmental processes of calcareous corpuscles could be divided into two stages: the intracellular formation stage and the extracellular metabolic stage. The calcareous corpuscles were formed in a cell which we named calcareous corpuscle forming cell. At the early stage of the formation, the corpuscles appeared to be secretory granules in the cells. With the development of the corpuscles, they became bead-shaped and lamellae-like, then the calcareous corpuscle forming cell enlarged and the organellae degenerated. Finally the corpuscles gathered to form particle substances with black dense background, while the nucleus and organellae of the forming cell all disappeared. There were 1-3 or 10-20 calcareous corpuscles in a mature forming cell. Then, the corpuscles were released to the parenchymal tissues and gradually appeared to be concentric lamella or an empty cavity during the metabolic process.

CONCLUSION

The calcareous corpuscles were formed in calcareous corpuscle forming cell and consumed in metabolic process in the parenchymal layer of Cysticercus cellulosae.

Therapeutically effective antibodies against amyloid-beta peptide target amyloid-beta residues 4-10 and inhibit cytotoxicity and fibrillogenesis

Immunization of transgenic mouse models of Alzheimer disease using amyloid-beta peptide (Abeta) reduces both the Alzheimer disease-like neuropathology and the spatial memory impairments of these mice. However, a therapeutic trial of immunization with Abeta42 in humans was discontinued because a few patients developed significant meningo-encephalitic cellular inflammatory reactions. Here we show that beneficial effects in mice arise from antibodies selectively directed against residues 4-10 of Abeta42, and that these antibodies inhibit both Abeta fibrillogenesis and cytotoxicity without eliciting an inflammatory response. These findings provide the basis for improved immunization antigens as well as attempts to design small-molecule mimics as alternative therapies.

Bipedal stance exercise and prostaglandin E2 (PGE2) and its synergistic effect in increasing bone mass and in lowering the PGE2 dose required to prevent ovariectomized-induced cancellous bone loss in aged rats

Previous reports have shown that bone loss was partially prevented by bipedal stance "exercise" following ovariectomy (ovx), and it was well documented that prostaglandin E2 (PGE(2)) had an anabolic effect on the rat skeleton. The aim of this study was to determine whether lower doses of PGE(2) could prevent ovx-induced cancellous bone loss with the combination of bipedal stance exercise. Seventy-eight 10-month-old female Sprague-Dawley rats were either ovariectomized or sham-operated on day 0 and then treated with PGE(2) (0, 0.3, or 1 mg/kg per day) and/or housed in normal height cages (NC, 28 cm) or raised cages (RC, 33 cm) for 8 weeks. Bone histomorphometry was performed on the double-fluorescent-labeled proximal tibial metaphysis. In sham rats, 1 mg/kg PGE(2) + RC had synergistic effects in increasing trabecular bone area, width, and number by stimulating mineral apposition rate and bone formation rate. As expected, ovx induced cancellous bone loss, accompanied by elevated activation frequency. Without RC, PGE(2) monotherapy prevented ovx-induced bone loss at the 1 mg/kg per day dose, whereas this prevention effect was observed at the 0.3 mg/kg per day dose when combined with RC. Similar to their effects in sham rats, PGE(2) and RC had synergistic effects in augmenting cancellous bone mass and architecture and maintaining the elevated bone formation but depressing bone resorption and activation frequency. We conclude that bipedal stance exercise lowers the PGE(2) dose required to prevent ovx-induced cancellous bone loss in the proximal tibial metaphysis in aged rats.

Ultrastructural observation on the transformation of the spermatozoon in spermatogenesis of Taeniid cestodes

AIM

To study the transformation of taeniid spermatozoon during spermatogenesis on the ultrastructure level.

METHODS

Transmission electronmicroscopy.

RESULTS

This paper was the second part of the ultrastructural observations on the spermatogenesis in Taeniid cestodes: The transformation of the spermatozoon. The 64-spermatid-plasmodium was generated from the secondary meiosis of the 32 rose-like secondary spermatocytes. The transformation of the spermatozoon was a complex process. Firstly, both the cytoplasm and nucleus of the spermatid elongated while the cytoplasm increased and connected to the cytoplasmic mass (cytophore). Secondly, the chromatins of nucleus polymerized to a thread-bundle-like structure. Finally, it detached from the cytoplasm mass and became a mature spermatozoon. The mature spermatozoon was a thread-like structure, about 16.2-18.6 microns in length and 0.35-0.45 micron in diameter. There were two structurally distinct parts: the part with the nucleus was the head and the part without the nucleus was the tail. The head measured about 5-6 microns in length, 1/3 of the total body length and contained an elongated nucleus which twined around the axoneme without mitochondria. The tail was about 11.2-16.6 microns in length. Throughout the core of the tail was an axoneme with typical "9 + 1" structure. The anterior of the tail, just behind the head, were some mitochondria, about 1.6-1.7 microns in total length which twined around the axoneme. The posterior of the tail contained only an axoneme. In cross-section of the spermatozoon, about 46 microtubules were beneath the plasma membrane.

CONCLUSION

The transformation of the spermatozoon is a very complex process.

Cupule Removal and Caryopsis Scarification Improves Germination of Eastern Gamagrass Seed

Eastern gamagrass (Tripsacum dactyloides L.) is a warm-season, perennial grass with high palatability and productivity. However, poor stand establishment, often due to seed dormancy, limits its widespread use. Seed dormancy is often caused by structures surrounding the embryo, the physiological state of the embryo itself, or a combination of these factors. The eastern gamagrass dispersal unit is a floret within a thick, hard cupule. The objective of this study was to evaluate effects of cupule (including lemma and palea) removal and caryopsis scarification on germination of eastern gamagrass by means of different commercial seed lots produced in different locations and years. Germination tests were conducted at 20/30 degrees C alternating temperature with light during 30 degrees C for 8 h daily. Germination counts were made every 7 d. After 28 d, the germination of decupulated caryopses from different seed lots germinated from 16 to 49% across seed lots, compared with 5 to 18% germination for caryopses with cupule intact. Scarifying the pericarp over the embryo, however, resulted in germination of all dormant seeds. We conclude that while the cupule (including the lemma and palea) contributes to the dormancy of eastern gamagrass, the pericarp and/or testa are the main factors restricting germination of this species. In addition, caryopsis scarification increased the germination rate and the germination test could be shortened to 21 or even 14 d depending on the seed lot.