Mass, Spectroscopy, and Two-Neutron Decay of ^{16}Be

The structure and decay of the most neutron-rich beryllium isotope, ^{16}Be, has been investigated following proton knockout from a high-energy ^{17}B beam. Two relatively narrow resonances were observed for the first time, with energies of 0.84(3) and 2.15(5) MeV above the two-neutron decay threshold and widths of 0.32(8) and 0.95(15) MeV, respectively. These were assigned to be the ground (J^{π}=0^{+}) and first excited (2^{+}) state, with E_{x}=1.31(6)  MeV. The mass excess of ^{16}Be was thus deduced to be 56.93(13) MeV, some 0.5 MeV more bound than the only previous measurement. Both states were observed to decay by direct two-neutron emission. Calculations incorporating the evolution of the wave function during the decay as a genuine three-body process reproduced the principal characteristics of the neutron-neutron energy spectra for both levels, indicating that the ground state exhibits a strong spatially compact dineutron component, while the 2^{+} level presents a far more diffuse neutron-neutron distribution.

Licorice metabolite 18β-glycyrrhetinic acid activates G protein-gated inwardly rectifying K+ channels

BACKGROUND AND PURPOSE

Licorice (liquorice) is a common food additive and is used in Chinese medicine. Excess licorice intake can induce atrial fibrillation. Patients with atrial fibrillation possess constitutively activated G protein-gated inwardly rectifying K+ (GIRK) channels. Whether licorice affects GIRK channel activity is unknown. We aimed to clarify the effects of licorice ingredients on GIRK current and the mechanism of action.

EXPERIMENTAL APPROACH

A major component of licorice, glycyrrhizic acid (GA), and its metabolite, 18β-glycyrrhetinic acid (18β-GA), were tested. We performed electrophysiological recordings in Xenopus oocytes to examine the effects of GA and 18β-GA on various GIRK subunits (Kir 3.1-Kir 3.4), mutagenesis analyses to identify the crucial residues for drug action and motion analysis in cultured rat atrial myocytes to clarify effects of 18β-GA on atrial functions.

KEY RESULTS

GA inhibited Kir 3.1-containing channels, while 18β-GA activated all Kir 3.x subunits. A pore helix residue Phe137 in Kir 3.1 was critical for GA-mediated inhibition, and the corresponding Ser148 in Kir 3.2 was critical for 18β-GA-mediated activation. 18β-GA activated GIRK channel in a Gβγ -independent manner, whereas phosphatidylinositol 4,5-bisphosphate (PIP2 ) was essential for activation. Glu236 located at the cytoplasmic pore of Kir 3.2 appeared to be important to interactions with 18β-GA. In rat atrial myocytes, 18β-GA suppressed spontaneous beating via activation of GIRK channels.

CONCLUSION AND IMPLICATIONS

GA acts as a novel GIRK inhibitor, and 18β-GA acts as a novel GIRK activator. 18β-GA alters atrial function via activation of GIRK channels. This study elucidates the pharmacological activity of licorice ingredients and provides information for drug design.

A rumen virosphere with implications of contribution to fermentation and methane production, and endemism in cattle breeds and individuals

Viruses have a potential to modify the ruminal digestion via infection and cell lysis of prokaryotes, suggesting that viruses are related to animal performance and methane production. This study aimed to elucidate the genome-based diversity of rumen viral communities and the differences in virus structure between individuals and cattle breeds and to understand how viruses influence on the rumen. To these ends, a metagenomic sequencing of virus-like particles in the rumen of 22 Japanese cattle, including Japanese Black (JB, n = 8), Japanese Shorthorn (n = 2), and Japanese Black sires × Holstein dams crossbred steers (F1, n = 12) was conducted. Additionally, the rumen viromes of six JB and six F1 that were fed identical diets and kept in a single barn were compared. A total of 8,232 non-redundant viral genomes (≥5-kb length and ≥50% completeness), including 982 complete genomes, were constructed, and rumen virome exhibited lysogenic signatures. Furthermore, putative hosts of 1,223 viral genomes were predicted using tRNA and clustered regularly interspaced short palindromic repeat (CRISPR)-spacer matching. The genomes included 1 and 10 putative novel complete genomes associated with Fibrobacter and Ruminococcus, respectively, which are the main rumen cellulose-degrading bacteria. Additionally, the hosts of 22 viral genomes, including 2 complete genomes, were predicted as methanogens, such as Methanobrevibacter and Methanomethylophilus. Most rumen viruses were highly rumen and individual specific and related to rumen-specific prokaryotes. Furthermore, the rumen viral community structure was significantly different between JB and F1 steers, indicating that cattle breed is one of the factors influencing the rumen virome composition.IMPORTANCEHere, we investigated the individual and breed differences of the rumen viral community in Japanese cattle. In the process, we reconstructed putative novel complete viral genomes related to rumen fiber-degrading bacteria and methanogen. The finding strongly suggests that rumen viruses contribute to cellulose and hemicellulose digestion and methanogenesis. Notably, this study also found that rumen viruses are highly rumen and individual specific, suggesting that rumen viruses may not be transmitted through environmental exposure. More importantly, we revealed differences of viral communities between JB and F1 cattle, indicating that cattle breed is a factor that influences the establishment of rumen virome. These results suggest the possibility of rumen virus transmission from mother to offspring and its potential to influence beef production traits. These rumen viral genomes and findings provide new insights into the characterizations of the rumen viruses.

Direct toxicity of cigarette smoke extract on cardiac function mediated by mitochondrial dysfunction in Sprague-Dawley rat ventricular myocytes and human induced pluripotent stem cell-derived cardiomyocytes

Cigarette smoke has been recognized as a major risk factor for cardiovascular disease. However, its direct effects on rodent and human cardiomyocytes and its cellular mechanisms are not fully understood. In this study, we examined the direct effects of cigarette smoke extract (CSE) on contractile functions, intracellular Ca2+ dynamics, and mitochondrial function using cultured or freshly isolated rat ventricular myocytes and human induced pluripotent stem cell (iPS)-derived cardiomyocytes. In rat cardiomyocytes, CSE (≥0.1%) resulted in a time- and concentration-dependent cessation of spontaneous beating of cultured cardiomyocytes, eventually leading to cell death, which indicates direct toxicity. In addition, 1% CSE reduced contractile function of freshly isolated ventricular myocytes. Similar contractile dysfunction (declined spontaneous beating rate and contractility) was also observed in human iPS-derived cardiomyocytes. Regarding intracellular Ca2+ dynamics, 1% CSE increased the Ca2+ transient amplitude by greatly increasing systolic Ca2+ levels and slightly increasing diastolic Ca2+ levels. CSE also accelerated the decay of Ca2+ transients, and triggered spike-shaped Ca2+ transients in some cells. These results indicate that CSE causes abnormal Ca2+ dynamics in cardiomyocytes. Furthermore, CSE induced a cascade of mitochondrial dysfunctions, including increased mitochondrial reactive oxygen species, opening of mitochondrial permeability transition pore, reduction of mitochondrial membrane potential, and release of cytochrome c from mitochondria. These results suggest that CSE-induced contractile dysfunction and myocardial cell death is caused by abnormal Ca2+ dynamics and subsequent mitochondrial dysregulation, which would result in reduced bioenergetics and activation of cell death pathways.

Genetic relationships of feed efficiency and growth traits with carcass traits in Japanese Shorthorn cattle

In this study, we examined genetic parameters for feed efficiency, growth, and carcass traits in Japanese Shorthorn cattle, based on 714 performance tests and 15,790 field carcass records. Feed efficiency traits, including residual feed intake (RFI) and residual body weight gain (RG), were calculated. Single-trait and two-trait animal models were used to estimate heritability and genetic correlations. Heritability estimates for feed efficiency traits were found to be low to moderate (ranging from 0.03 to 0.36); notably, heritability was moderate for RG and low for RFI. Estimates for genetic correlations between feed efficiency traits and average daily gain (DG) were favorably moderate to high (absolute values of 0.43-0.85), and those with daily feed intake were low (absolute values of 0.00-0.32). We also estimated a high genetic correlation between RG and DG. The backfat thickness (BF) of bull calves showed favorable or no genetic correlation estimates with feed efficiency and growth traits, whereas RG and BF showed favorable or no genetic correlation estimates with carcass traits. Our findings indicate that genetic improvements in both feed utilization ability and carcass traits could be achieved by utilizing RG and BF in Japanese Shorthorn cattle.

Identification of 146 Metagenome-assembled Genomes from the Rumen Microbiome of Cattle in Japan

The rumen contains a complex microbial ecosystem that degrades plant materials, such as cellulose and hemicellulose. We herein reconstructed 146 nonredundant, rumen-specific metagenome-assembled genomes (MAGs), with ≥50% completeness and <10% contamination, from cattle in Japan. The majority of MAGs were potentially novel strains, encoding various enzymes related to plant biomass degradation and volatile fatty acid production. The MAGs identified in the present study may be valuable resources to enhance the resolution of future taxonomical and functional studies based on metagenomes and metatranscriptomes.

Modification of exosomes with carbonate apatite and a glycan polymer improves transduction efficiency and target cell selectivity

Exosomes are secreted from a variety of cells and transmit parental cell-derived biomolecules, such as nucleic acids and proteins, to recipient cells in distant organs. In addition to their important roles in both physiological and pathological conditions, exosomes are expected to serve as natural drug carriers without any cytotoxicity, immunogenicity, or tumorigenicity. However, the use of exosomes as drug delivery tools is limited due to the low uptake efficiency of the target cells, insufficient release of the contents from the endosome to the cytosol, and possible adverse effects caused by the delivery to non-target cells. In the present study, we examined the effects of the modification of exosomes with carbonate apatite or a lactose-carrying polymer. Using newly generated monitoring exosomes that contain either firefly luciferase or fused mCherry/enhanced green fluorescent protein, we demonstrated that the modification of exosomes with carbonate apatite improved their release from the endosome into the cytosol in recipient cells. Meanwhile, the modification of exosomes with a lactose-carrying polymer enhanced the selective delivery to parenchymal hepatocytes. These modified exosomes may provide an efficient strategy for macromolecule therapy for incurable diseases that cannot be treated with conventional small-molecule compounds.

Evaluation of inbreeding and genetic diversity in Japanese Shorthorn cattle by pedigree analysis

The Japanese Shorthorn is a Japanese Wagyu breed maintained at a small population size. We assessed the degree of inbreeding and genetic diversity among Japanese Shorthorn cattle using pedigree analysis. We analyzed the pedigree records of registered Japanese Shorthorn born between 1980 and 2018, after evaluating the pedigree completeness. The average of the actual inbreeding coefficients increased at the same rates annually from approximately 1.5% in 1980 to 4.2% in 2018 and was higher than the expected inbreeding coefficients over time. The effective population size based on the individual coancestry rate largely decreased from 127.8 in 1980 to 82.6 in 1999, and then remained almost constant at approximately 90. Three effective numbers of ancestors decreased over time until 1995, then remained almost constant. In particular, the effective number of founder genomes (N_ge) decreased from 43.8 in 1980 to 11.9 in 2018. The index of genetic diversity based on N_ge decreased from 0.99 in 1980 to 0.96 in 2018 due to genetic drift in non‐founder generations. Changes in inbreeding and genetic diversity parameters were similar between Japanese Shorthorn and other Japanese Wagyu breeds, but the magnitude of the changes was lower in the Japanese Shorthorn.

Identification of the core rumen bacterial taxa and their population dynamics during the fattening period in Japanese Black cattle

The rumen microbiota comprises a vast range of bacterial taxa, which may affect the production of high‐quality meat in Japanese Black cattle. The aim of this study was to identify core rumen microbiota in rumen fluid samples collected from 74 Japanese Black cattle raised under different dietary conditions using 16S rRNA gene amplicon sequencing. In the rumen of fattening Japanese Black cattle, 10 bacterial taxa, showing >1% average relative abundance and >95% prevalence, irrespective of the dietary conditions and the fattening periods, were identified as the core rumen bacterial taxa, which accounted for approximately 80% of the rumen microbiota in Japanese Black cattle. Additionally, population dynamics of the core rumen bacterial taxa revealed two distinct patterns: Prevotella spp. and unclassified Bacteroidales decreased in the mid‐fattening period, whereas unclassified Clostridiales, unclassified Ruminococcaceae, Ruminococcus spp., and unclassified Christensenellaceae increased during the same period. Therefore, the present study reports the wide distribution of the core rumen bacterial taxa in Japanese Black cattle, and the complementary nature of the population dynamics of these core taxa, which may ensure stable rumen fermentation during the fattening period.

Quasifree Neutron Knockout Reaction Reveals a Small s-Orbital Component in the Borromean Nucleus ^{17}B

A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus ^{17}B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s_{1/2} and 0d_{5/2} orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s_{1/2}. Our finding of such a small 1s_{1/2} component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in ^{17}B. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.

Surface Localization of the Dineutron in ^{11}Li

The formation of a dineutron in the ^{11}Li nucleus is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in ^{11}Li via the (p,pn) knockout reaction at 246  MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum. A comparison with reaction calculations reveals the localization of the dineutron at r∼3.6  fm. The results also support the density dependence of dineutron formation as deduced from Hartree-Fock-Bogoliubov calculations for nuclear matter.

Single-blind randomized clinical trial of transinguinal preperitoneal repair using self-expanding mesh patch vs. Lichtenstein repair for adult male patients with primary unilateral inguinal hernia

PURPOSE

The aim of the study was to compare proportions of chronic postoperative inguinal pain (CPIP) and other surgical outcomes between transinguinal preperitoneal repair with modified Kugel patch (MK) and Lichtenstein repair (LR).

METHODS

Two-hundred adult male patients with primary unilateral inguinal hernia were randomized into MK or LR groups. The primary endpoint was CPIP, pain at 6 months after surgery. Secondary outcomes included recurrence rate, incidence of postoperative complications, time until return to activities, inguinal pain and sensory disturbances assessed at 1 week, 1 month, 3, 6, and 12 months after the operation using an 11-point numerical rating scale (NRS). The study was an intention-to-treat analysis.

RESULTS

In comparison of MK (n = 100) and LR (n = 100) with similar backgrounds, proportions of CPIP were similar (7.2 vs. 11.1%, p = 0.3452). Favorable outcomes for MK were duration of operation (32 vs. 40 min, p < 0.0001), NRS of foreign body sensation at 1 year (0 [0-1] vs. 0 [0-2], p = 0.0067), and NRS of numbness at 1 month (0 [0-1] vs. 0 [0-3], p = 0.0078) after the operation.

CONCLUSIONS

In regard to CPIP, the short-term results of MK and LR were similar.

How Different is the Core of ^{25}F from ^{24}O_{g.s.} ?

The structure of a neutron-rich ^{25}F nucleus is investigated by a quasifree (p,2p) knockout reaction at 270A  MeV in inverse kinematics. The sum of spectroscopic factors of π0d_{5/2} orbital is found to be 1.0±0.3. However, the spectroscopic factor with residual ^{24}O nucleus being in the ground state is found to be only 0.36±0.13, while those in the excited state is 0.65±0.25. The result shows that the ^{24}O core of ^{25}F nucleus significantly differs from a free ^{24}O nucleus, and the core consists of ∼35% ^{24}O_{g.s.}. and ∼65% excited ^{24}O. The result may infer that the addition of the 0d_{5/2} proton considerably changes neutron structure in ^{25}F from that in ^{24}O, which could be a possible mechanism responsible for the oxygen dripline anomaly.

Protective effect of T3 peptide, an active fragment of tumstatin, against ischemia/reperfusion injury in rat heart

Ischemia/reperfusion (I/R)-induced oxidative stress is a serious clinical problem in the reperfusion therapy for ischemic diseases. Tumstatin is an endogenous bioactive peptide cleaved from type IV collagen α3 chain. We previously reported that T3 peptide, an active subfragment of tumstatin, exerts cytoprotective effects on H₂O₂-induced apoptosis through the inhibition of intracellular reactive oxygen species (ROS) production in H9c2 cardiomyoblasts. In this study, we investigated whether T3 peptide has cardioprotective effects against I/R injury by using in vitro and ex vivo experimental models. H9c2 cardiomyoblasts were stimulated with oxygen and glucose deprivation (OGD) for 12 h followed by reoxygenation for 1-8 h (OGD/R; in vitro model). The cells were treated with T3 peptide (30-1000 ng/ml) during OGD. Ten minutes after the pre-perfusion of T3 peptide (300 ng/ml), Langendorff perfused rat hearts were exposed to ischemia for 30 min followed by reperfusion for 1 h (ex vivo model). T3 peptide inhibited OGD/R-induced apoptosis through the inhibition of mitochondrial ROS production and dysfunction in H9c2 cardiomyoblasts. T3 peptide also prevented I/R-induced cardiac dysfunction, arrhythmia and myocardial infarction in the perfused rat heart. In conclusion, we for the first time demonstrated that T3 peptide exerts cardioprotective effects against I/R injury.

Extraction of the Landau-Migdal Parameter from the Gamow-Teller Giant Resonance in ^{132}Sn

The key parameter to discuss the possibility of the pion condensation in nuclear matter, i.e., the so-called Landau-Migdal parameter g^{'}, was extracted by measuring the double-differential cross sections for the (p,n) reaction at 216  MeV/u on a neutron-rich doubly magic unstable nucleus, ^{132}Sn with the quality comparable to data taken with stable nuclei. The extracted strengths for Gamow-Teller (GT) transitions from ^{132}Sn leading to ^{132}Sb exhibit the GT giant resonance (GTR) at the excitation energy of 16.3±0.4(stat)±0.4(syst)  MeV with the width of Γ=4.7±0.8  MeV. The integrated GT strength up to E_{x}=25  MeV is S_{GT}^{-}=53±5(stat)_{-10}^{+11}(syst), corresponding to 56% of Ikeda's sum rule of 3(N-Z)=96. The present result accurately constrains the Landau-Migdal parameter as g^{'}=0.68±0.07, thanks to the high sensitivity of the GTR energy to g^{'}. In combination with previous studies on the GTR for ^{90}Zr and ^{208}Pb, the result of this work shows the constancy of this parameter in the nuclear chart region with (N-Z)/A=0.11 to 0.24 and A=90 to 208.

New Insights into the Role of Basement Membrane-Derived Matricryptins in the Heart

The extracellular matrix (ECM), which contributes to structural homeostasis as well as to the regulation of cellular function, is enzymatically cleaved by proteases, such as matrix metalloproteinases and cathepsins, in the normal and diseased heart. During the past two decades, matricryptins have been defined as fragments of ECM with a biologically active cryptic site, namely the 'matricryptic site,' and their biological activities have been initially identified and clarified, including anti-angiogenic and anti-tumor effects. Thus, matricryptins are expected to be novel anti-tumor drugs, and thus widely investigated. Although there are a smaller number of studies on the expression and function of matricryptins in fields other than cancer research, some matricryptins have been recently clarified to have biological functions beyond an anti-angiogenic effect in heart. This review particularly focuses on the expression and function of basement membrane-derived matricryptins, including arresten, canstatin, tumstatin, endostatin and endorepellin, during cardiac diseases leading to heart failure such as cardiac hypertrophy and myocardial infarction.

T3 peptide, an active fragment of tumstatin, inhibits H2O2-induced apoptosis in H9c2 cardiomyoblasts

Tumstatin, a cleaved fragment of α3 chain of type IV collagen, is an endogenous anti-angiogenetic peptide. Although the expression level of tumstatin changes in the heart tissues of certain experimental cardiac disease models, its effect on cardiomyocytes has not been clarified. In this study, we examined the effects of T3 peptide, an active subfragment of tumstatin, on hydrogen peroxide (H₂O₂)-induced cell death in H9c2 cardiomyoblasts. Cell viability was examined by a cell counting assay. Staining using 4', 6-diamidino-2-phenylindole was performed to observe nuclear morphology. Western blotting was performed to examine cleaved caspase-3 expression. Mitochondrial membrane potential and morphology were detected by a Mito Tracker Red staining. Intracellular reactive oxygen species production was examined by 2', 7'-dichlorodihydrofluorescein diacetate staining. T3 peptide (300, 1000ng/ml) suppressed H₂O₂ (1mM)-induced cell death, apoptotic changes of nuclei and cleaved caspas-3 expression in a concentration-dependent manner. T3 peptide also inhibited H₂O₂-induced loss of mitochondrial membrane potential, mitochondrial fission and reactive oxygen species production. Cilengitide, an integrin α_vβ₃/α_vβ₅ inhibitor, prevents the inhibitory effect of T3 peptide on H₂O₂-induced reactive oxygen species production. In conclusion, T3 peptide inhibits H₂O₂-induced apoptosis at least partly via the inhibition of intracellular reactive oxygen species production through the action on integrin.

Endostatin inhibits bradykinin-induced cardiac contraction

.Endogenous fragments of extracellular matrix are known to possess various biological effects. Levels of endostatin, a fragment of collagen type XVIII, increase in certain cardiac diseases, such as cardiac hypertrophy and myocardial infarction. However, the influence of endostatin on cardiac contraction has not been clarified. In the present study, we investigated the effects of endostatin on bradykinin-induced atrial contraction. Isometric contractile force of mouse isolated left atria induced by electrical current pulse was measured. Voltage-dependent calcium current of guinea pig ventricular myocytes was measured by a whole-cell patch-clamp technique. Endostatin (100–1,000 ng/ml) alone treatment had no influence on left atrial contraction. On the other hand, pretreatment with endostatin (300 ng/ml) significantly inhibited bradykinin (1 µM)-induced contraction and voltage-dependent calcium current. These data suggest that endostatin may decrease bradykinin-induced cardiac contraction perhaps through the inhibition of voltage-dependent calcium channel.

Endostatin inhibits T-type Ca2+ channel current in guinea pig ventricular myocyte

Endostatin, a fragment of collagen XVIII, is known as an endogenous angiogenesis inhibitor, and its serum concentration increases in various cardiovascular diseases. T-type Ca²⁺ channel, low voltage-activated Ca²⁺ channel, is not expressed in adult ventricular myocytes. Re-expression of T-type Ca²⁺ channels in cardiac myocytes is thought to be involved in the development of cardiac hypertrophy. We examined the effects of endostatin on T-type Ca²⁺ channel current by whole-cell patch clamp technique in freshly isolated adult guinea pig ventricular myocytes, which exceptionally express T-type Ca²⁺ channels. Although endostatin 300 ng/ml had no effect on L-type Ca²⁺ current, it significantly inhibited T-type Ca²⁺ current. These data indicate that endostatin can be an endogenous inhibitor of T-type Ca²⁺ channels in the cardiac myocytes.

A simple and sensitive method for detection of Bacillus anthracis by loop-mediated isothermal amplification

AIMS

To develop a rapid and simple system for detection of Bacillus anthracis using a loop-mediated isothermal amplification (LAMP) method and determine the suitability of LAMP for rapid identification of B. anthracis infection.

METHODS AND RESULTS

A specific LAMP assay targeting unique gene sequences in the bacterial chromosome and two virulence plasmids, pXO1 and pXO2, was designed. With this assay, it was possible to detect more than 10 fg of bacterial DNA per reaction and obtain results within 30-40 min under isothermal conditions at 63 degrees C. No cross-reactivity was observed among Bacillus cereus group and other Bacillus species. Furthermore, in tests using blood specimens from mice inoculated intranasally with B. anthracis spores, the sensitivity of the LAMP assay following DNA extraction methods using a Qiagen DNeasy kit or boiling protocol was examined. Samples prepared by both methods showed almost equivalent sensitivities in LAMP assay. The detection limit was 3.6 CFU per test.

CONCLUSIONS

The LAMP assay is a simple, rapid and sensitive method for detecting B. anthracis.

SIGNIFICANCE AND IMPACT OF THE STUDY

The LAMP assay combined with boiling extraction could be used as a simple diagnostic method for identification of B. anthracis infection.

Rapid and simple detection of Clostridium botulinum types A and B by loop-mediated isothermal amplification

AIMS

To develop a convenient and rapid detection method for toxigenic Clostridium botulinum types A and B using a loop-mediated isothermal amplification (LAMP) method.

METHODS AND RESULTS

The LAMP primer sets for the type A or B botulinum neurotoxin gene, BoNT/A or BoNT/B, were designed. To determine the specificity of the LAMP assay, a total of 14 C. botulinum strains and 17 other Clostridium strains were tested. The assays for the BoNT/A or BoNT/B gene detected only type A or B C. botulinum strains, respectively, but not other types of C. botulinum or strains of other Clostridium species. Using purified chromosomal DNA, the sensitivity of LAMP for the BoNT/A or BoNT/B gene was 1 pg or 10 pg of DNA per assay, respectively. The assay times needed to detect 1 ng of DNA were only 23 and 22 min for types A and B, respectively. In food samples, the detection limit per reaction was one cell for type A and 10 cells for type B.

CONCLUSIONS

The LAMP is a sensitive, specific and rapid detection method for C. botulinum types A and B.

SIGNIFICANCE AND IMPACT OF THE STUDY

The LAMP assay would be useful for detection of C. botulinum in environmental samples.

The prevalence of bovine herpesvirus-1 in traditional cattle in Southern Province, Zambia

A study was conducted to determine the prevalence of bovine herpesvirus-1 (BHV-1), which causes infectious bovine rhinotracheitis, in cattle destined for market in Southern Province, Zambia. A total of 116 nasal secretion samples were tested using the direct fluorescent antibody test, while blood samples from the same cattle were examined by a commercial enzyme-linked immunosorbent assay kit. The prevalence of the BHV-1 antigens in cattle was 23.28% (27/116), while the mean prevalence of the BHV-1 antibodies was 48.28% (56/116). This study showed that cattle in transit to markets could easily spread the virus, which was reactivated by the stress of trekking for long distances under unfavourable conditions, to the other cattle with which they came into contact. Thus, these transit cattle posed a serious threat to other bovines. Systems of cattle trading where cattle must be transported a long wayto market should be reviewed by the authorities to minimise the conditions that may exacerbate the spread of infection.

Inhibition of arthritis by systemic administration of endostatin in passive murine collagen induced arthritis

OBJECTIVE

To investigate the arthritis inhibiting effect of endostatin, known to have potent antiangiogenic activity, systemically given to animal models of rheumatoid arthritis (RA).

METHODS

Four kinds of monoclonal anti-type II collagen antibody followed by lipopolysaccharide (LPS) three days later were given to 6 week old, female Balb/c mice to induce arthritis. Three groups of mice received 0.2 mg/kg/day, 2 mg/kg/day, and 10 mg/kg/day of endostatin, respectively, whereas a control group received phosphate buffered saline (PBS). Endostatin or PBS was given for 13 days, starting before the development of arthritis. Arthritis was evaluated by arthritis scores and hind paw thicknesses. Mice were killed for histological examination on the 22nd day after the administration of monoclonal anti-type II collagen antibody.

RESULTS

Arthritis developed within three days after LPS administration in both the control and endostatin treatment groups. No difference in the development rate of arthritis was noted between the control and endostatin treatment groups. Arthritis scores remained significantly lower in the endostatin 10 mg/kg/day group than in the control group. Hind paw thicknesses also remained significantly smaller in the endostatin 10 mg/kg/day group than in the control group. Histopathological examination showed that synovial thickening and subchondral bone erosion improved more in the endostatin treatment groups than in the control group.

CONCLUSION

The systemic administration of endostatin had an arthritis inhibiting effect in RA animal models. Endostatin inhibited, in particular, pannus formation and bone destruction.

Latent HIV-1 reactivation in transgenic mice requires cell cycle -dependent demethylation of CREB/ATF sites in the LTR

OBJECTIVE

We previously produced a line of transgenic mice that carried the HIV-1 genome deficient in the gene. Although the HIV-1 genome in the lymphocytes was dormant under normal physiological conditions, it could be reactivated by lipopolysaccharide (LPS) administration via induction of interleukin-1alpha/beta and tumour necrosis factor-alpha. In this report, we analysed further the reactivation mechanism of the latent HIV-1 using this transgenic mouse model.

DESIGN

and methods: Possible involvement of CpG methylation in HIV-1 latency was examined by treating transgenic lymphocytes with a demethylating agent, 5'-azacytidine. CpG methylation in the HIV-1 long terminal repeat (LTR) was analysed using the bisulfite genomic sequencing method. As previous studies suggested that CpG demethylation depended on the cell cycle progression, we analysed the relation between cell cycle progression and LPS-induced reactivation of HIV-1 by labelling lymphocytes with an intracellular fluorescein, carboxyfluorescein diacetate succinimidyl ester.

RESULTS

We found that 5'-azacytidine enhanced HIV-1 expression ninefold compared to treatment with LPS alone. Furthermore, HIV-1 p24 induction by LPS was observed only in cells that had undergone cell division, while induction was prevented in cells in which cell cycle progression was blocked either by mimosine, aphidicolin, or nocodazole. LPS-induced HIV-1 reactivation was associated with demethylation of two CpG sites located in the CREB/ATF binding sites in the HIV-1 LTR in a cell cycle-dependent manner.

CONCLUSIONS

These observations indicate that cell cycle progression-dependent demethylation of the CREB/ATF sites in the LTR is crucial for the reactivation of latent HIV-1 genome in transgenic mice.

Rhabdomyosarcoma (botryoid sarcoma) of the urinary bladder in a Maltese

A urinary bladder tumour was diagnosed in a two-year-old female Maltese with haematuria and pollakiuria on the basis of ultrasonography and pneumocystography findings. The mass was resected, and the bladder was preserved at surgery. Histological and immunohistochemical examination confirmed the tumour to be a rhabdomyosarcoma, which has rarely been reported in small breeds of dog. There was no recurrence of the tumour at the original site in the urinary bladder two months later, when the dog died due to metastasis to the liver. This is believed to be the first report of bladder rhabdomyosarcoma in a Maltese.

Design and synthesis of carboxylate inhibitors for matrix metalloproteinases

A series of carboxylate compounds were prepared from N(alpha)-substituted 2,3-diaminopropionic acid and were tested for efficacy as matrix metalloproteinase (MMP) inhibitors. During modeling of the initial compound 10a, we utilized three-dimensional structure modeling software (InsightII/Discover Ver. 2.98). Some of the prepared carboxylate derivatives, such as carbamate compounds (12c,d, 22) and sulfonamide compounds (14b,c), proved to be effective MMP-1 inhibitors (with IC50 values of a 10(-6) M order), depending on the substituent at the N(alpha)-position of 2,3-diaminopropionic acid. Some of them were also evaluated for inhibition of stromelysin-1 (MMP-3), and the sulfonamide compound 14c exceeded the lead compound 5b in its MMP-3 inhibitory potency. For the carbamate compounds, we investigated the minimum molecular size at which the MMP-1 inhibitory potency was maintained, and found that this was P3-P1' compound 10b.

T cell apoptosis causes peripheral T cell depletion in mice transgenic for the HIV-1 vpr gene

Vpr, an accessory protein of HIV, is known to affect viral replication as well as cell growth, differentiation, and apoptosis in vitro. To investigate its pathogenicity in vivo, we have produced mice transgenic for the HIV-1 vpr gene with the CD4 enhancer/promoter. Interestingly, apoptotic death of T lymphocytes was enhanced in those mice, causing marked reduction of T cells in lymphatic organs and peripheral blood. Involvement of Bcl-x, Bax, and Caspase-1, but not of the Fas-Fas ligand system, was suggested in the apoptotic processes. These observations suggest that Vpr is involved in the pathogenesis of T cell depletion in HIV-infected people.

[A questionnaire survey on the theory of postoperative infection prophylaxis in gynecology]

A questionnaire survey on the theory of postoperative infection prophylaxis was conducted to obtain the consensus on perioperative antimicrobial use among gynecologists in Japan in the period from April to July 2000. Fifty-six of the 83 gynecologists replied, and the following consensus was obtained. An antimicrobial prophylaxis (AMP) agent should be chosen based on their efficacy against the pathogens expected to be contaminants, such as Staphylococcus spp., Escherichia coli and Bacteroides fragilis group. Use an AMP agent that archives a bactericidal concentrations in both the serum and operating site. Use an AMP agent that has little unfavourable side effects. The newer agents should be considered as a therapeutics for postoperative infections. The therapeutic antimicrobial agents having no cross-resistance to the AMP agents should be used, if postoperative infection is suspected or developed. The most commonly used agent for clean operations are cefazolin (CEZ), followed by cefotiam (CTM) and cefmetazole (CMZ). The most commonly used agent for clean-contaminated operations where low grade level of bacterial invasion expected is CTM, followed by CEZ and CMZ, where as operations where mild grade level of bacterial invasion expected is flomxef (FMOX), followed by CTM and other cephalosporins.

Localization of interferon regulatory factor-1 in human endometrium throughout the menstrual cycle

OBJECTIVE

To determine the expression and localization of IRF-1 in human endometrium throughout the menstrual cycle.

DESIGN

A comparative study.

SETTING

Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine.

PATIENTS

Thirty-eight women aged 33 to 46 years, with regular menstrual cycles and nonpathological endometrium, undergoing hysterectomy.

INTERVENTION(S)

Endometrial tissues were obtained from operative samples.

MAIN OUTCOME MEASURE(S)

Expression of IRF-1 mRNA throughout the menstrual cycle was investigated using semiquantitative reverse transcription-polymerase chain reaction. Localization of IRF-1 protein was determined using immunohistochemistry.

RESULT(S)

IRF-1 mRNA was expressed in the human endometrium at each phase of the menstrual cycle. The immunoreactivity for IRF-1 was observed in the extranuclear compartment of the surface and glandular epithelial cells, both during the proliferative and secretory phases, as well as in the gland secretion during the secretory phase. In contrast, stromal cells were nearly unstained.

CONCLUSION(S)

IRF-1 was localized in the human endometrium, implying that this nuclear protein plays some role other than as a transcription factor.

An investigation of heavy metal exposure and risks to wildlife in the Kafue flats of Zambia

Exposure and ecological risks to heavy metals (copper, zinc, manganese, iron) at Lochnivar and Blue Lagoon National Parks in wildlife dependent on the Kafue river contaminated with mining waste was evaluated. Samples included water, fish, grasses and Kafue Lechwe (Kobus leche kafuensis) liver. At both parks copper ranged from 0.03-0.04 mg/l; 3.0-6.0 mg/kg; 11.0-44.0 mg/kg; trace -199.0 mg/kg; while zinc was 0.01 mg/l; 32.0-82.0 mg/kg; 15.0-21.0 mg/kg; and 52.0-138.0 mg/kg; in water, fish, grasses and lechwe, respectively. Manganese ranges were 0.15-0.16 mg/l; 7.0-18.0 mg/kg; 51.0-145.0 mg/kg; and 40.0-53.0 mg/kg while iron ranges were 0.13-0.14 mg/l; 26.0-134.0 mg/kg; 1766.0-1797.0 mg/kg; and 131.0-856.0 mg/kg; in water, fish, grasses and lechwe, respectively. Levels in all samples except water were high indicating potential for adverse effects.

[Therapy-related myeloid leukemia following platinum-based chemotherapy for ovarian cancer]

A 40-year-old woman, who had suffered from AML (M1) in 1983, developed ovarian cancer (stage IIIc) in December 1996 after long-term remission. She underwent surgical resection of the cancer, 10 courses of standard chemotherapy and tandem PBSCT (total dose: CBDCA 6,750 mg, CDDP 200 mg, CPA 16,000 mg, THP-ADR 450 mg). After receiving the last course of chemotherapy in June 1998, she was referred to our hospital in September 1998 because of pancytopenia. Laboratory findings showed pancytopenia with 34% leukemic cells, which were positive for alpha NBE and negative for POX and CAE. Surface-marker analysis of the leukemic cells showed positivity for CD11c, CD33, CD56, and DR, and chromosome analysis revealed 47, XX, +8. The patient was diagnosed as having AML (M5a), and received induction therapy consisting of IDR and Ara-C, which led to complete remission. As she had not received etoposide, this case was thought to have been therapy-related leukemia due to the platinum agents used for treating the ovarian cancer.

Structure of the infected cell protein 0 gene of canine herpesvirus

The canine herpesvirus infected cell protein 0 (CICP0) gene was sequenced. The CICP0 gene was transcribed as a 1.4 kb mRNA from the end of the unique long region nearby the internal repeat during early phase of productive infection of the virus. An open reading frame of the gene encodes a polypeptide of 333 amino acids. The RING finger domain and acidic transcriptional activation domain were found at the N-terminus and within the middle region in the deduced amino acid sequence, respectively, suggesting that the CICP0, like the ICP0 of herpes simplex virus 1, is a transactivating protein.

IL-15 expression at human endometrium and decidua

A large number of natural killer (NK) cells appear in human uterine mucosa during the secretory phase and first trimester pregnancy. We investigated the expression of interleukin (IL)-15, a possible stimulator for these NK cells, in human endometrium and first trimester decidua. Semiquantitative reverse transcriptase-polymerase chain reaction revealed that IL-15 mRNA expression was stronger during the secretory phase and first trimester pregnancy than during the proliferative phase. Immunohistochemistry revealed that immunoreactivity for anti-IL-15 was higher during the secretory phase than it was during the proliferative phase. This was prominent in the perivascular stromal cells around invading spiral arteries during the mid- to late-secretory phase. In first trimester decidua, endothelial cells were also stained as strongly as stromal cells. A membrane-bound IL-15 molecule was detected on the surface of first trimester decidual cells by flow cytometry. Progesterone stimulated the release of soluble IL-15 in the supernatant of cultured decidual cells. These results suggest that IL-15 expression in human uterine mucosa corresponds to the fluctuation of uterine NK cells and that its production is hormonally controlled, especially by progesterone.