Rat Synapsin 1 Promoter Mediated Transgene Expression in Testicular Cell Types

Previous reports described the rat synapsin 1 promoter as primarily neuron selective. However, ectopic expression of a transgene under the rat synapsin 1 promoter was also detected in testis from some transgenic mouse lines. Here we investigate which cells within the testis express a transgene consisting of the rat synapsin 1 promoter fused with luciferase. Synapsin 1-luciferase expression vectors were introduced into HeLa cells, into TM3 cells derived from mouse testicular Leydig cells, and into one-cell embryos to make transgenic mice. Indirect immunofluorescence suggests that nontransfected TM3 cells do not express endogenous synapsin 1. TM3 stable transfectants, however, expressed luciferase under the direction of the synapsin 1 promoter, in both promoter orientations. HeLa cells displayed only low levels of activity. Transgenic mice carrying the synapsin 1-luciferase construct displayed high levels of luciferase activity in the brain, spinal cord, and testis. Enriched populations of prepuberal types A and B spermatogonia and adult Leydig cells, pachytene spermatocytes, and round spermatids prepared from transgenic mice all displayed substantial luciferase activity. Thus, the rat synapsin 1 promoter can mediate reporter gene expression in neurons and testicular cell types.

Common variants in the 5' region of the leptin gene are associated with body mass index in men from the National Heart, Lung, and Blood Institute Family Heart Study

Linkage of body mass index (BMI) to a broad region of chromosome 7q22-35 has been reported in multiple studies. We previously published a multipoint LOD score of 4.9 at D7S1804 for BMI from the National Heart, Lung, and Blood Institute Family Heart Study. Leptin (LEP), the human homolog of the mouse obesity (ob) gene, is positioned near the linkage peak and is the most prominent candidate gene in this region. Interest in LEP as a susceptibility gene for human obesity has led to numerous linkage and association studies, but the results of these studies are still controversial. In the present study, we employed family-based tests of association with both a quantitative measure of BMI adjusted for age and sex and a dichotomously defined obesity trait. We genotyped 29 single-nucleotide polymorphisms (SNPs) spanning 240 kb around the LEP gene in the 82 extended pedigrees with the strongest evidence for linkage. When the programs TRANSMIT and FBAT were used, a number of SNPs showed association in men but not women, for both the quantitative and qualitative trait definitions (P<.05). Five SNPs (H1328084, H1328083, H1328082, H1328081, and H1328080) positioned 2 kb beyond the previously defined promoter region showed strong association in single-marker and multiple-marker haplotype analysis. This five-marker haplotype (frequency 49% in this sample) is overtransmitted to obese offspring (P=.00005). All five of these SNPs are predicted to modify transcription-factor binding sites. This may indicate new functional variants in an extended promoter region of LEP.

Quantum magnetic excitations from stripes in copper oxide superconductors

In the copper oxide parent compounds of the high-transition-temperature superconductors the valence electrons are localized--one per copper site--by strong intra-atomic Coulomb repulsion. A symptom of this localization is antiferromagnetism, where the spins of localized electrons alternate between up and down. Superconductivity appears when mobile 'holes' are doped into this insulating state, and it coexists with antiferromagnetic fluctuations. In one approach to describing the coexistence, the holes are believed to self-organize into 'stripes' that alternate with antiferromagnetic (insulating) regions within copper oxide planes, which would necessitate an unconventional mechanism of superconductivity. There is an apparent problem with this picture, however: measurements of magnetic excitations in superconducting YBa2Cu3O6+x near optimum doping are incompatible with the naive expectations for a material with stripes. Here we report neutron scattering measurements on stripe-ordered La1.875Ba0.125CuO4. We show that the measured excitations are, surprisingly, quite similar to those in YBa2Cu3O6+x (refs 9, 10) (that is, the predicted spectrum of magnetic excitations is wrong). We find instead that the observed spectrum can be understood within a stripe model by taking account of quantum excitations. Our results support the concept that stripe correlations are essential to high-transition-temperature superconductivity.

Topiramate Extends the Therapeutic Window for Hypothermia-Mediated Neuroprotection After Stroke in Neonatal Rats

Background and Purpose— Critical factors influencing the neuroprotective efficacy of postischemic hypothermia include depth, duration, and time of onset of cooling. In clinical practice, there is an unavoidable lag between the hypoxic-ischemic (HI) insult and the opportunity to initiate cooling. We hypothesized that early administration of a neuroprotective agent in combination with later-onset cooling could represent an effective therapeutic intervention after neonatal HI. We evaluated whether treatment with topiramate, a clinically available anticonvulsant, increased the efficacy of delayed post-HI hypothermia in a neonatal rat stroke model.

Methods— Postnatal day 7 (P7) rats underwent right carotid artery ligation followed by 1.5 hours of exposure to 8% oxygen. Fifteen minutes post-HI, animals received injections of topiramate (30 mg/kg) or PBS. Cooling was initiated 3 hours later (“delayed hypothermia”) in all animals (3 hours, in 27°C incubator). Functional outcome (forepaw response to vibrissae stimulation) and pathology (morphometric lesion measurements) were evaluated at P15 and P35.

Results— Neither topiramate nor delayed hypothermia alone conferred protection in this protocol. Combined treatment with topiramate and delayed hypothermia improved both performance and pathological outcome in P15 and P35 rats compared with PBS-treated animals that underwent delayed hypothermia concurrently. At P15, functional measures were better in topiramate-treated animals (mean correct forepaw response 9.3/10 versus 4.8/10; P <0.001), and there was >50% reduction in tissue loss ( P <0.001); trends were similar at P35.

Conclusions— Our data provide the impetus for further evaluation of therapeutic approaches that combine drug therapy with delayed-onset cooling after neonatal HI brain injury.

A haplotype at the PARK3 locus influences onset age for Parkinson's disease: the GenePD study

OBJECTIVE

To identify a haplotype influencing onset age for Parkinson's disease (PD) in the PARK3 region on chromosome 2p13.

METHODS

Single nucleotide polymorphisms (SNP) spanning 2.2 Mb and located in or near potential candidate genes were used to fine map the PARK3 region in 527 patients with familial PD, from 264 families.

RESULTS

TT homozygotes for rs1876487 (G/T) had a 7.4-year younger mean age at onset (p = 0.005) compared to patients with GT and GG genotypes. Furthermore, SNP flanking the sepiapterin reductase (7,8-dihydrobiopterin: NADP+ oxidoreductase) (SPR) gene, rs1876487 (p = 0.02) and rs1150500 (p = 0.04), were associated with younger onset age among persons who did not carry the 174 allele of D2S1394. The SPR gene is implicated in dopamine synthesis. Haplotype analysis of three SNP-rs2421095, rs1876487, rs1561244-revealed an association with onset age (p = 0.023) and a haplotype of A-T-G alleles was associated with younger onset for PD (p = 0.005).

CONCLUSIONS

A haplotype at the PARK3 locus, harboring the SPR gene, is associated with onset age of PD. This may suggest a role for the SPR gene in modifying the age at onset of PD.

Lipopolysaccharide-induced-neuroinflammation increases intracellular accumulation of amyloid precursor protein and amyloid beta peptide in APPswe transgenic mice

The present study was designed to examine whether brain inflammation caused by systemic administration of lipopolysaccharides (LPS) alters the expression/processing of amyloid precursor protein (APP) and increases the generation of amyloid beta peptide (Abeta). APPswe transgenic (Tg) mice were treated with either LPS or phosphate-buffered saline (PBS). In LPS-treated APPswe mice, Abeta1-40/42 was 3-fold and APP was 1.8-fold higher than those in PBS-treated mice (P < 0.05) by ELISA, Western blots and immunoprecipitation-mass spectrometry (IP-MS) ProteinChip analysis. Numbers of Abeta- and APP-immunoreactive neurons (Abeta(+) and APP(+) neurons) increased significantly in LPS-treated APPswe mice; APP(+) and Abeta(+) neurons in neocortex were associated with an increased number of F4/80-immunoreactive microglia (F4/80(+) microglia) in their anatomical environment. Our findings demonstrate that experimental neuroinflammation increases APP expression/processing and causes intracellular accumulation of Abeta. It remains to be seen whether such events can cause neuronal dysfunction/degeneration and, with time, lead to extracellular Abeta deposits, as they occur in Alzheimer's disease.

[Investigation on genotype constitution of different Plasmodium vivax isolates and its geographical distribution in China]

OBJECTIVE

To investigate the population constitution and geographical distribution of Plasmodium vivax in China using molecular technique.

METHODS

Blood-spot filter paper samples with related epidemiological data were collected from vivax malaria patients living in malarious area of 10 provinces (autonomous region) in China. Semi-nested- or nested-allelic-specific PCR genotyping method was used to identify CSP genotypes, families and types of Plasmodium vivax of each isolate from these patients.

RESULTS

Of 384 field isolates of Plasmodium vivax, 258 temperate zone family strains were identified, including 14 allelic variant genotypes spreading among 10 sampling provinces; allelic variants sized less than 731 bp were only seen in 5 provinces in southern China; 79 tropical zone family strains including 5 genotypes were also distributed in 5 provinces of southern China south to 25 degrees N. lat; and 14 PV Type-2 strains including 2 genotypes were found in some areas of Hainan and Yunnan Provinces. In addition, 33 isolates from genotype-mixed infections were revealed.

CONCLUSION

At present, area north to 25 degrees N. lat. of the country is the sole area prevalent for Plasmodium vivax family strains of temperate zone; there is overlapping distribution of P. v. of temperate zone family and tropical zone family of this parasite in the southern China south to 25 degrees N. lat; where the most complex isolate constitution is in Yunnan and Hainan Provinces, and PV Type-2 strains have been found in some areas of the two provinces. Besides, there were 2 groups of genotype with distinct geographic distribution feature within the temperate zone family.

High resolution spectroscopy of the 12Lambda B hypernucleus produced by the (e,e'K+) reaction

High-energy, cw electron beams at new accelerator facilities allow electromagnetic production and precision study of hypernuclear structure, and we report here on the first experiment demonstrating the potential of the (e,e'K+) reaction for hypernuclear spectroscopy. This experiment is also the first to take advantage of the enhanced virtual photon flux available when electrons are scattered at approximately zero degrees. The observed energy resolution was found to be approximately 900 keV for the (12)(Lambda)B spectrum, and is substantially better than any previous hypernuclear experiment using magnetic spectrometers. The positions of the major excitations are found to be in agreement with a theoretical prediction and with a previous binding energy measurement, but additional structure is also observed in the core excited region, underlining the future promise of this technique.

Site-directed mutagenesis of amino acids in the cytoplasmic loop 6/7 of Na,K-ATPase

The loop between transmembrane helices 6 and 7 (L6/7) of P-type ATPases has been suggested to be important for the functional linkage of ion binding and enzyme phosphorylation or to be a site of initial cation binding. To investigate the role of L6/7 in Na,K-ATPase, alanine substitutions were made for charged and conserved residues in L6/7 of the human alpha1 subunit and the proteins were expressed in yeast for analysis. All mutants except the triple mutant E825A/E828A/D830A bound ouabain. Although the equilibrium dissociation constant for ouabain binding by most mutants was similar to the wild-type value, the K(d) of R837A for ouabain binding was approximately 15-fold higher than the wild-type K(d). (18)O exchange measurements indicated that the apparent affinity of this mutant for Pi was reduced about 3-fold. The concentration dependence of KCl inhibition of ouabain binding or of NaCl inhibition of ouabain binding revealed 2-4-fold changes in the apparent affinity for cations in the E825A, E828A, and R837A mutants. The E825A and E828A mutants lost the ability to bind ouabain after extraction with 0.1% SDS or after brief heating, indicating that these mutations affected the stability of the enzyme. The ATPase activity of the other mutants was measured after extraction of crude yeast membranes with 0.1% SDS. For all mutants except R834A, R837A, and R848A, the activity was at least 50% of wild-type activity.

Structure of end states for a Haldane spin chain

Inelastic neutron scattering was used to probe edge states in a quantum spin liquid. The experiment was performed on finite length antiferromagnetic spin-1 chains in Y2BaNi1-xMgxO5. At finite fields, there is a Zeeman resonance below the Haldane gap. The wave-vector dependence of its intensity provides direct evidence for staggered magnetization at chain ends, which decays exponentially towards the bulk [xi=8(1) at T=0.1 K]. Continuum contributions to the chain-end spectrum indicate interchain segment interactions. We also observe a finite size blueshift of the Haldane gap.

Molecular dissection of seedling-vigor and associated physiological traits in rice

seedling-vigor is important for crop establishment. There have been reported quantitative trait locus (QTL) analyses on seedling-vigor related morphological traits. However, physiological understanding of these detected QTLs is rather limited. In this study, we employed a recombinant inbred population to detect QTLs for seedling-vigor traits and physiological traits related to seedling-vigor. Germination rate and seedling growth were measured to quantify seedling-vigor. Total amylase activity, alpha-amylase activity, reducing sugar content, root activity and seed weight were determined. Correlations were observed between the seedling-vigor and physiological traits. QTL analysis reveals that the intervals of RG393-C1087-RZ403 on chromosome 3, C246-RM26-C1447 and R830-R3166-RG360-C734b on chromosome 5, and the interval of Waxy on chromosome 6 are the four main chromosomal regions controlling seedling-vigor. Several QTLs for amylase activities, reducing sugar content and root activity were localized in the similar regions as the QTLs for seedling-vigor. The results suggest that these traits were under the control of pleiotropic and/or closely linked QTLs. The implications of the results in the understanding of the physiological basis of seedling-vigor were discussed.

High-resolution imaging of living retina through optic adaptive retinal imaging system

PURPOSE

To evaluate the possibility as well as the usage of adaptive optics in high-resolution retinal imaging.

METHODS

From March to November 2001, the fundus of 25 adults were checked by using Optic Adaptive Retinal Imaging System (OAS). The age of the subjects varied from 18 - 48 years. All had normal visual acuity from 0.9 to 1.0. No abnormality was found in the ocular examination, and their medical as well as ocular history was unremarkable.

RESULTS

High-resolution images of the retinal cells, photoreceptor and bipolar cell, were analysed. In these images, the cells are clearly resolved. The density of the photoreceptor at area 1.5 degree from the foveloa is around 40 000 - 50 000/mm2. At area 3 degree, it drops to less than 30 000/mm2.

CONCLUSION

Optic Adaptive Retinal Imaging System (AOS) is able to get high-resolution image of retinal cells in living human eyes. It may be widely used in ophthalmology experimentally and clinically.

Characterization of the main effects, epistatic effects and their environmental interactions of QTLs on the genetic basis of yield traits in rice

Main effects, epistatic effects and their environmental interactions of QTLs are all important genetic components of quantitative traits. In this study, we analyzed the main effects, epistatic effects of the QTLs, and QTL by environment interactions (QEs) underlying four yield traits, using a population of 240 recombinant inbred lines from a cross between two rice varieties tested in replicated field trials. A genetic linkage map with 220 DNA marker loci was constructed. A mixed linear model approach was used to detect QTLs with main effects, QTLs involved in digenic interactions and QEs. In total, 29 QTLs of main effects, and 35 digenic interactions involving 58 loci were detected for the four traits. Thirteen QTLs with main effects showed QEs; no QE was detected for the QTLs involved in epistatic interactions. The amount of variations explained by the QTLs of main effect were larger than the QTLs involved in epistatic interactions, which in turn were larger than QEs for all four traits. This study illustrates the ability of the analysis to assess the genetic components underlying the quantitative traits, and demonstrates the relative importance of the various components as the genetic basis of yield traits in this population.

Fibroma induction in rat skin following single or multiple doses of 1.0 GeV/nucleon 56Fe ions from the Brookhaven Alternating Gradient Synchrotron (AGS)

Rat skin was exposed to the plateau region of the 1.0 GeV/nucleon 56Fe beam at the Brookhaven AGS. Rats were irradiated or not with single of split doses of 56Fe or argon; some 56Fe-exposed rats were fed 250 ppm retinyl acetate continuously in the lab chow beginning 1 week before irradiation. All lesions were noted, photographed and identified for eventual histological diagnosis. The preponderance of the tumors so far are fibromas. The data show that single doses of 56Fe ions are 2 or 3 fold more effective than argon in producing tumors at 4.5 Gy but are about equally effective at 3.0 Gy and 9.0 Gy. The presence of 250 ppm retinyl acetate in the lab chow reduced the incidence of tumors by about 50-60% in comparison to groups exposed only to the radiation. These are preliminary findings based on only about one-fourth the eventual number of tumors expected.

Immunohistochemical localization of mitogen-activated protein kinase (MAPK) family and morphological changes in rat heart after ischemia-reperfusion injury

The mitogen-activated protein kinase (MAPK) family is considered to be activated by stress, but the role of the MAPK family is still unknown in cardiac pathology. In the present study, not only the localization of MAPKs such as the extracellular responsive kinase (ERK), c-jun N-terminal kinase (JNK), and p38 MAPK (p38), but also ultrastructural changes were investigated in the ischemia-reperfusion model of Wistar rats. At 5, 10, 30, 60, and 180 min reperfusion after 30 min ischemia by occluding the coronary artery, the expression of these MAPKs was increased in blood vessels and cardiomyocytes by Western blotting and immunohistochemical methods. In addition, after ischemia reperfusion, various ultrastructural changes such as decreased glycogen granules, mitochondrial swelling, and myolysis were observed in the blood vessels and cardiomyocytes. These results suggest that protein kinases may regulate numerous biological processes, including the regulation of contraction and ion transport.

Observation of columnar microstructure in step-graded Si1-xGex/Si films using high-resolution X-ray microdiffraction

Columnar microstructure in step-graded Si(1-x)Ge(x)/Si(001) structures with low threading dislocation densities has been determined using high angular resolution (approximately 0.005 degrees ) x-ray microdiffraction. X-ray rocking curves of a 3-microm-thick strain-relaxed Si(0.83)Ge(0.17) film show many sharp peaks and can be simulated with a model having a set of Gaussians having narrow angular widths (0.013 degrees -0.02 degrees ) and local ranges of tilt angles varying from 0.05 degrees to 0.2 degrees. These peaks correspond to individual tilted rectangular columnar micrograins having similar (001) lattice spacings and average areas of 0.8 to 2.0 microm(2).

Human placental trophoblast as an in vitro model for tumor progression

The human placenta is a highly invasive tumor-like structure in which a subpopulation of placental trophoblast cells known as the "extravillous trophoblast" (EVT) invades the uterine decidua and its vasculature to establish adequate fetal-maternal exchange of molecules. By utilizing in vitro-propagated short-lived EVT cell lines we found that molecular mechanisms responsible for their invasiveness are identical to those of cancer cells; however, unlike cancer cells, their proliferation, migration, and invasiveness in situ are stringently controlled by decidua-derived transforming growth factor (TGF)-beta. By SV40T antigen transfection of normal EVT cells followed by a forced crisis regimen in culture we produced an immortalized premalignant derivative that is hyperproliferative, hyperinvasive, and deficient in gap-junctional intercellular communication. Both premalignant and malignant EVT (JAR and JEG-3 choriocarcinoma) cell lines were found to be TGF-beta-resistant. Using these cell lines, we investigated genetic changes responsible for transition of the normal EVT cells to premalignant and malignant phenotype. Hyperinvasiveness in both cases resulted from a downregulation of tissue inhibitor of metalloprotease (TIMP)-1 and plasminogen activator inhibitor (PAI)-1 genes. In contrast to normal EVT cells, both cell types failed to upregulate these genes in response to TGF-beta. Loss of TGF-beta response in malignant EVT cells was explained by the loss of expression of Smad3 gene. Differential mRNA display of normal and premalignant EVT cells identified up- and down-regulation of numerous known or novel genes in premalignant EVT cells, with potential oncogenic and (or) tumor-suppressor functions, e.g., loss of fibronectin and insulin-like growth factor binding protein (IGFBP-5). Premalignant EVT cells also lost IGF receptor type 2 (IGFR-II). IGFBP-5 was shown to be a negative regulator of IGF-1-induced proliferation of premalignant EVT cells, so that loss of IGFBP-5 as well as IGFR-II permitted their unrestricted proliferation in an IGF-I-rich microenvironment of the fetal-maternal interface. The present model may be a good prototype for identifying genetic changes underlying epithelial tumor progression.

Developmental sensitivity of associative learning to cholesterol synthesis inhibitors

Patients with Smith-Lemli-Opitz syndrome, a genetic disorder associated with severe mental retardation, are unable to convert 7-dehydrocholesterol to cholesterol. Treatment of rats with agents that block cholesterol synthesis produces a sterol profile reminiscent of Smith-Lemli-Opitz patients i.e., low levels of cholesterol accompanied by the appearance of its immediate precursor 7-dehydrocholesterol. In previous work, chronic inhibition of cholesterol synthesis in just-weaned rats impaired acquisition of the classically conditioned eyeblink response. The present study had two primary goals--(1) to determine whether the learning impairment depended on the age in which treatment was initiated; and (2) to determine whether the deficit was associative or due to performance factors. Consistent with earlier work, acquisition of the eyeblink conditioned response was impaired when the 30-day treatment was initiated on postnatal day (PND) 21. Reactivity to acoustic stimuli and to eyelid stimulation were normal, suggesting that the learning impairment was associative in nature. The learning impairment was transitory; acquisition was normal when evaluated 30 days after the cessation of treatment. When treatment was initiated 30 days after weaning (PND 51), acquisition of the eyeblink response was normal. However, brain sterols of young adult rats were less affected than those of just-weaned rats. Thus, there is a developmental sensitivity to cholesterol synthesis blocking agents both in terms of their effects on brain sterols and new motor learning.

Determination of total N-nitroso compounds and their precursors in frankfurters, fresh meat, dried salted fish, sauces, tobacco, and tobacco smoke particulates

Total N-nitroso compounds (NOC) and NOC precursors (NOCP) were determined in extracts of food and tobacco products. Following Walters' method, NOC were decomposed to NO with refluxing HBr/HCl/HOAc/EtOAc and NO was measured by chemiluminescence. NOC were determined after sulfamic acid treatment to destroy nitrite, and NOCP were determined after treatment with 110 mM nitrite and then sulfamic acid. Analysis without HBr gave results < or =20% of those with HBr. This NOC method was efficient for nitrosamines but not nitrosoureas. The standard nitrosation for determining NOCP gave high yields for readily nitrosated amines, including 1-deoxy-1-fructosylvaline, but not for simple amines, dipeptides, and alkylureas. Mean NOC and NOCP results were (respectively, in micromol/kg of product) 5.5 and 2700 for frankfurters, 0.5 and 660 for fresh meat, 5.8 and 5800 for salted, dried fish, and 660 and 2900 for chewing tobacco (all for aqueous extracts) and 220 and 20000 nmol/cigarette for MeCN extracts of cigarette smoke filter pads.