A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067

Planets with radii between that of the Earth and Neptune (hereafter referred to as 'sub-Neptunes') are found in close-in orbits around more than half of all Sun-like stars1,2. However, their composition, formation and evolution remain poorly understood3. The study of multiplanetary systems offers an opportunity to investigate the outcomes of planet formation and evolution while controlling for initial conditions and environment. Those in resonance (with their orbital periods related by a ratio of small integers) are particularly valuable because they imply a system architecture practically unchanged since its birth. Here we present the observations of six transiting planets around the bright nearby star HD 110067. We find that the planets follow a chain of resonant orbits. A dynamical study of the innermost planet triplet allowed the prediction and later confirmation of the orbits of the rest of the planets in the system. The six planets are found to be sub-Neptunes with radii ranging from 1.94R⊕ to 2.85R⊕. Three of the planets have measured masses, yielding low bulk densities that suggest the presence of large hydrogen-dominated atmospheres.

Geriatric nutritional risk index as the prognostic factor in older patients with fragility hip fractures

This study investigated the long-term survival and incidence of secondary fractures after fragility hip fractures. The 5-year survival rate was 62%, and the mortality risk was seen in patients with GNRI < 92. The 5-year incidence of secondary fracture was 22%, which was significantly higher in patients with a BMI < 20.

BACKGROUND

Malnutrition negatively influences the postoperative survival of patients with fragility hip fractures (FHFs); however, little is known about their association over the long term.

OBJECTIVE

This study evaluated the ability of the geriatric nutritional risk index (GNRI) as a risk factor for long-term mortality after FHFs.

METHODS

This study included 623 Japanese patients with FHFs over the age of 60 years. We prospectively collected data on admission and during hospitalization and assessed the patients' conditions after discharge through a questionnaire. We examined the long-term mortality and the incidence of secondary FHFs and assessed the prognostic factors.

RESULTS

The mean observation period was 4.0 years (range 0-7 years). The average age at the time of admission was 82 years (range 60-101 years). The overall survival after FHFs (1 year, 91%; 5 years, 62%) and the incidence of secondary FHFs were high (1 year, 4%; 5 years, 22%). The multivariate Cox proportional hazard analysis revealed the risk factors for mortality as older age (hazard ratio [HR] 1.04), male sex (HR 1.96), lower GNRI score (HR 0.96), comorbidities (malignancy, HR 2.51; ischemic heart disease, HR 2.24; revised Hasegawa dementia scale ≤ 20, HR 1.64), no use of active vitamin D3 on admission (HR 0.46), and a lower Barthel index (BI) (on admission, HR 1.00; at discharge, HR 0.99). The GNRI scores were divided into four risk categories: major risk (GNRI, < 82), moderate risk (82-91), low risk (92-98), and no risk (> 98). Patients at major and moderate risks of GNRI had a significantly lower overall survival rate (p < 0.001). Lower body mass index (BMI) was also identified as a prognostic factor for secondary FHFs (HR 0.88 [p = 0.004]).

CONCLUSIONS

We showed that older age, male sex, a lower GNRI score, comorbidities, and a lower BI are risk factors for mortality following FHFs. GNRI is a novel and simple predictor of long-term survival after FHFs.

Selective Killing of HIV-Infected Cells by Liposomes Composed of dimyristoylphosphatidylcholine/phosphatidylserine/cholesterol

We have previously shown that liposomes containing fragment A of diphtheria toxin, which were prepared by the detergent-dialysis method with egg phosphatidylcholine, phosphatidylserine and cholesterol, possess a selective killing activity against human immunodeficiency virus (HIV)-1-infected cells, but not against uninfected cells (Ikuta et al., 1987). Since the liposomes were found to be unstable in human plasma in vitro, we prepared improved liposomes by the extrusion method with dimyristoylphosphatidylcholine instead of egg phosphatidylcholine. These liposomes were found to be very stable in human plasma, and also possessed the selective killing activity against HIV-1-infected cells. In addition, it was found that the fragment A in the liposomes was not necessary for the selective cell killing activity. The cell killing activity and selectivity of HIV-1-infected cells of the liposomes were remarkably affected by cholesterol content and the acyl chain length of the saturated fatty acid of phosphatidylcholines. These data suggest that membranes of liposomes can interact specifically with HIV-1-infected cells, but not with uninfected cells, resulting in the inhibition of cell proliferation.

Characterization of two anti-dengue human monoclonal antibodies prepared from PBMCs of patients with dengue illness in Thailand

The global spread of the four dengue virus (DENV) serotypes (dengue-1 to -4) has made this virus a major and growing public health concern. Generally, pre-existing neutralizing antibodies derived from primary infection play a significant role in protecting against subsequent infection with the same serotype. By contrast, these pre-existing antibodies are believed to mediate a non-protective response to subsequent heterotypic DENV infections, leading to the onset of dengue illness. In this study, two monoclonal antibodies prepared by using peripheral blood mononuclear cells (PBMCs) from patients with dengue fever were characterized. Epitope mapping revealed that amino acid residues 254-278 in domain II of the viral envelope protein E were the target region of these antibodies. A database search revealed that certain sequences in this epitope region showed high conservation among the four serotypes of DENV. These two human monoclonal antibodies could neutralize DENV-2,-4 more effectively than DENV-1,-3. The amino acid sequences could not explain this difference in neutralizing activity. However, the 3D structure results showed that amino acid 274 could be the critical residue for the difference in neutralization. These results may provide basic information for the development of a dengue vaccine.

microRNA-18a induces apoptosis in colon cancer cells via the autophagolysosomal degradation of oncogenic heterogeneous nuclear ribonucleoprotein A1

It is well known that microRNAs (miRs) are abnormally expressed in various cancers and target the messenger RNAs (mRNAs) of cancer-associated genes. While (miRs) are abnormally expressed in various cancers, whether miRs directly target oncogenic proteins is unknown. The present study investigated the inhibitory effects of miR-18a on colon cancer progression, which was considered to be mediated through its direct binding and degradation of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1). An MTT assay and xenograft model demonstrated that the transfection of miR-18a induced apoptosis in SW620 cells. A binding assay revealed direct binding between miR-18a and hnRNP A1 in the cytoplasm of SW620 cells, which inhibited the oncogenic functions of hnRNP A1. A competitor RNA, which included the complementary sequence of the region of the miR-18a-hnRNP A1 binding site, repressed the effects of miR-18a on the induction of cancer cell apoptosis. In vitro single and in vivo double isotope assays demonstrated that miR-18a induced the degradation of hnRNP A1. An immunocytochemical study of hnRNP A1 and LC3-II and the inhibition of autophagy by 3-methyladenine and ATG7, p62 and BAG3 siRNA showed that miR-18a and hnRNP A1 formed a complex that was degraded through the autophagolysosomal pathway. This is the first report showing a novel function of a miR in the autophagolysosomal degradation of an oncogenic protein resulting from the creation of a complex consisting of the miR and a RNA-binding protein, which suppressed cancer progression.

Low-intensity resistance training after high-intensity resistance training can prevent the increase of central arterial stiffness

Although high-intensity resistance training increases arterial stiffness, low-intensity resistance training reduces arterial stiffness. The present study investigates the effect of low-intensity resistance training before and after high-intensity resistance training on arterial stiffness. 30 young healthy subjects were randomly assigned to a group that performed low-intensity resistance training before high-intensity resistance training (BLRT, n=10), a group that performed low-intensity resistance training after high-intensity resistance training (ALRT, n=10) and a sedentary control group (n=10). The BLRT and ALRT groups performed resistance training at 80% and 50% of one repetition maximum twice each week for 10 wk. Arterial stiffness was measured using carotid-femoral and femoral-ankle pulse wave velocity (PWV). One-repetition maximum strength in the both ALRT and BLRT significantly increased after the intervention (P<0.05 to P<0.01). Both carotid-femoral PWV and femoral-ankle PWV after combined training in the ALRT group did not change from before training. In contrast, carotid-femoral PWV after combined training in the BLRT group increased from before training (P <0.05). Femoral-ankle PWV after combined training in the both BLRT and ALRT groups did not change from before training. These results suggest that although arterial stiffness is increased by low-intensity resistance training before high-intensity resistance training, performing low-intensity resistance training thereafter can prevent the increase of arterial stiffness.

Decompression procedure using a microendoscopic technique for thoracic myelopathy caused by ossification of the ligamentum flavum

BACKGROUND

Microendoscopic discectomy (MED) is one of the minimally invasive endoscopic procedures for treating lumbar disc herniation. The aim of this case report is to describe a patient with thoracic ossification of the ligamentum flavum (OLF) that was completely removed using the microendoscopic technique.

CASE REPORT

We report on a 62-year-old male patient who presented with thoracic myelopathy caused by OLF at the Th11-12. A posterior decompression via spinous process splitting approach using the microendoscopic technique at the Th11-12 was performed. The bilateral ossified ligamentum flavum could be en bloc removed separately. A sufficient decompression of the spinal cord and the spinal canal with no evidence of damage on the paraspinal muscles was demonstrated on magnetic resonance images after surgery. The patient's neurological symptoms were alleviated at 24 months after surgery. There was no evidence of postoperative instability at the final follow-up.

CONCLUSION

The authors found that the microendoscopic technique could be applied to decompression surgery for thoracic OLF. The procedure could provide a sufficient decompression with minimum damage to the paraspinal muscles. However, the microendoscopic procedure should be indicated only for select thoracic OLF, such as OLF without fusion at the middle of the spinal canal and OLF without dural ossification, because of its technical difficulties.

Variability of parvovirus B19 genotype 2 in plasma products with different compositions in the inactivation sensitivity by liquid-heating

BACKGROUND AND OBJECTIVES

Our previous report showed that parvovirus B19 genotype 1 in different solutions derived from plasma preparations showed different heat-sensitivity patterns during liquid-heating. In this study, we similarly examined B19 genotype 2.

MATERIALS AND METHODS

Two plasma samples one containing B19 genotype 1 and the other genotype 2 DNA were used. Four process samples collected immediately before the heat treatment step in the manufacture of albumin, immunoglobulin, haptoglobin and antithrombin preparations were spiked with B19 and subsequently treated at 60°C for 10 h. A low pH immunoglobulin solution was also spiked with B19 and treated at room temperature for 14 days. Infectivity was then measured.

RESULTS

B19 genotype 2, similar to genotype 1, showed three patterns of inactivation: (i) a rapid inactivation in the albumin and immunoglobulin preparations, (ii) a slow inactivation in the haptoglobin preparation and (iii) only limited inactivation in the antithrombin preparation. Its sensitivity in the low pH immunoglobulin solutions also resembled that of genotype 1.

CONCLUSION

Both genotypes 1 and 2 of B19 varied in sensitivity to liquid-heating and low pH among different plasma preparations.

STM Observation on the Initial growth of Amorphous and Microcrystalline Silicon Films

Direct nanoscale observation on the nucleation and growth of hydrogenated amorphous and microcrystalline silicon on graphite substrates was made using scanning tunneling microscopy, atomic force microscopy, and Raman scattering spectroscopy. Nucleation of hydrogenated silicon clusters is initiated through the nucleation sites created by reactive hydrogen species coming from the source gas plasma. The difference in spatial distribution of nucleated clusters at the initial stage of deposition between a-Si:H and μc-Si:H is ascribed to the difference in the number density of nucleation sites which results in difference in the diffusion length of a SiH3 radical at the initial stage of deposition on the graphite substrate. The RMS roughness of μc-Si:H films is larger than that of a-Si:H when the film thickness is larger than 10 Å, which is opposite to the behavior at the initial nucleation stage on the graphite substrate.

Lack of antibodies against the antigen domain 2 epitope of cytomegalovirus (CMV) glycoprotein B is associated with CMV disease after renal transplantation in recipients having the same glycoprotein H serotypes as their donors

Cytomegalovirus (CMV) reinfection of seropositive individuals has been associated with adverse outcomes in organ transplantation and is a frequent cause of congenital infection. Previously we demonstrated that mismatching of CMV glycoprotein H (gH) serotypes was associated with CMV disease after renal transplantation. Because the antigen domain 2 (AD2) epitope of glycoprotein B (gB) is conserved among CMV isolates and is one of the known targets of neutralizing antibodies, in this study we investigated whether antibodies against the epitope contribute to protection from CMV reinfection in renal transplantation, irrespective of gH serological matching. For this purpose, the gB and gH serology and clinical outcomes were analyzed retrospectively for 77 transplant recipients in the donor positive/recipient positive setting, who were managed by preemptive strategy. We found that there was a good negative correlation between the numbers of antigenemia-positive cells and the levels of antibodies against gB AD2 in the CMV-gH antibody matched group, but not in the CMV-gH antibody mismatched group. None of the recipients with antibodies against both gB AD2 and strain-specific epitopes of gH have experienced CMV disease during 6 month after transplantation, while 28% of those who lacked either/both antibody response needed preemptive therapy. Because the outcome was statistically significant, antibodies against gB AD2 can be a useful indicator to predict emergence of CMV disease for preemptive therapy, in addition to antibodies against the mismatched gH types.

Effects of muscle contraction timing during resistance training on vascular function

Muscle contractions in normal resistance training are performed by eccentric (ECC, lowering phase) and concentric (CON, lifting phase) muscle contractions. However, the difference in effects of timing of muscle contraction during resistance training on arterial stiffness is unknown. This study investigated the effect of muscle contraction timing during resistance training on vascular function in healthy young adults. Thirty healthy men were randomly assigned to group of resistance training with quick lifting and slow lowering (ERT, n=10), group of resistance training with slow lifting and quick lowering (CRT, n=10) and sedentary groups (SED, n=10). The ERT and CRT groups underwent two supervised resistance-training sessions per week for 10 weeks. The ERT group performed the on set of 8-10 repetitions with 3 s ECC and 1 s CON muscle contractions. In contrast, the CRT group performed the on set of 8-10 repetitions with 1 s ECC and 3 s CON muscle contractions. Brachial-ankle pulse wave velocity (baPWV) after ERT did not change from baseline. In contrast, baPWV after CRT increased from baseline (from 1049+/-37 to 1153+/-30 cm s(-1), P<0.05). No significant changes in flow-mediated dilation were observed in the ERT and CRT groups. These values did not change in the SED group. These findings suggest that although both training does not deteriorate a vascular endothelial function, resistance training with quick lifting and slow lowering (that is, ERT) prevent the stiffening of arterial stiffness.

Extent of hepatitis E virus elimination is affected by stabilizers present in plasma products and pore size of nanofilters

BACKGROUND AND OBJECTIVE

To investigate the physico-chemical properties of hepatitis E virus (HEV) with regard to inactivation/removal, we have studied four isolates with respect to sensitivity to heat during liquid/dry-heating as well as removal by nanofiltration.

MATERIALS AND METHODS

Hepatitis E virus in an albumin solution or phosphate-buffered saline (PBS) was liquid-heated at 60 degrees C for a preset time. HEV in a freeze-dried fibrinogen containing stabilizers was also dry-heated at 60 or 80 degrees C for a preset time. In addition, to clarify the removal of HEV, the purified virus in PBS was filtered using several types of virus-removal filter (nanofilters) that have different pore sizes. HEV infectivity or genome equivalents before and after the treatments were assayed by a semiquantitative cell-based infectivity assay or quantitative polymerase chain reaction assay, respectively.

RESULTS

Hepatitis E virus isolates in albumin solutions were inactivated slowly at 60 degrees C for 5 h and the resultant log reduction factor (LRF) was from 1.0 to > or = 2.2, whereas the virus in PBS was inactivated quickly to below the detection limit and the LRF was > or = 2.4 to > or = 3.7. The virus in a freeze dried fibrinogen containing trisodium citrate dihydrate and l-arginine hydrochloride as stabilizers was inactivated slowly and the LRF was 2.0 and 3.0, respectively, of the 72 h at 60 degrees C, but inactivated to below the detection limit within 24 h at 80 degrees C with an LRF of > or = 4.0. The virus in PBS was also confirmed as to be approximately 35 nm in diameter by nanofiltration. These results are useful for evaluating viral safety against HEV contamination in blood products.

CONCLUSION

The sensitivity of HEV to heat was shown to vary greatly depending on the heating conditions. On the other hand, the HEV particles were completely removed using 20-nm nanofilters. However, each inactivation/removal step should be carefully evaluated with respect to the HEV inactivation/removal capacity, which may be influenced by processing conditions such as the stabilizers used for blood products.

Demonstration of a Marek's disease virus-specific antigen in tumour lesions of chickens with Marek's disease using monoclonal antibody against a virus phosphorylated protein

By use of monoclonal antibody against a Marek's disease virus (MDV) serotype 1-specific phosphorylated protein, MDV antigen-positive cells were demonstrated in tumour lesions of various visceral organs of chickens with Marek's disease. However, these tumour lesions did not appear to have the MDV glycoproteins gA and gB, which are considered to be late gene products of the virus genome gA and gB as well as the phosphorylated protein were detected in the feather follicle epithelium, which is a permissive site for MDV replication.

Surgical Complications of Microendoscopic Procedures for Lumbar Spinal Stenosis

Microendoscopic discectomy (MED) is one of the minimally invasive endoscopic procedures for treating lumbar disc herniation. We have applied MED techniques to posterior decompression procedures for treating lumbar spinal stenosis (LSS). In the present study, we examined the surgical complications in 114 consecutive patients surgically treated with MED procedures for LSS. Intraoperative complications occurred in 9 patients. Six patients (5.3%) experienced a dural tear, and three (2.6%) had a fracture of an inferior facet. Early postoperative complications occurred in 13 patients. Twelve patients (10.5%) experienced transient neurological complications. The clinical outcomes at the mean 28-month follow-up were not affected by these surgical complications. Other major complications such as nerve injury and surgical site infection were not observed. Most of the complications occurred in the initial series of patients, and the incidence of complications decreased with an increase in the surgeon's experience and the application of several preventive measures against the complications. The surgeon should undergo training when MED techniques are applied in surgical treatment in order to recognize the specific complications associated with such procedures and apply preventive measures against these complications.

Variability of parvovirus B19 to inactivation by liquid heating in plasma products

BACKGROUND AND OBJECTIVES

Previously, we reported that although human parvovirus B19 in albumin and intravenous immunoglobulin preparations was rapidly inactivated during liquid heating, in contrast to other parvoviruses such as canine parvovirus, sensitivity to heat was highly dependent on the composition of the solution. In this study, we aimed to further elucidate the sensitivity to heat of B19 in haptoglobin and antithrombin (previously named antithrombin III) preparations during liquid heating.

MATERIALS AND METHODS

Two different solutions collected immediately before heat treatment of haptoglobin and antithrombin preparations were spiked with B19 and subsequently treated at 60 degrees C for 10 h. B19 DNA-positive, anti-B19 IgG/IgM-negative plasma was used as a source of B19. The residual infectivity in each sample was measured using a B19 cell-based infectivity assay with an mRNA polymerase chain reaction.

RESULTS

B19 in different plasma preparations showed different heat-sensitivity patterns during liquid heating: (i) slow inactivation in haptoglobin preparations, and (ii) only limited inactivation in antithrombin preparations. The kinetics of inactivation was greatly different from that in our previous studies in which the virus was shown to be rapidly inactivated in albumin and intravenous immunoglobulin preparations.

CONCLUSION

B19 has unique properties in terms of heat sensitivity, depending on the composition of the solution during liquid heating. This finding may indicate the need for caution when interpreting the sensitivity of B19 to heat.

Effects of eccentric and concentric resistance training on arterial stiffness

It has been suggested that resistance training (RT) increases arterial stiffness. The purpose of the present study was to clarify the effect of eccentric RT (ERT) and concentric RT (CRT) on arterial stiffness in female adults by an interventional study. In total, 29 healthy female subjects were randomly assigned to either the ERT group (n=10), CRT group (n=10) or sedentary (SED) group (n=9). The ERT and CRT groups performed resistance training three times a week for 8 weeks. We determined brachial blood pressure, brachial-ankle pulse wave velocity (baPWV), carotid artery intimamedial thickness (IMT) and carotid arterial lumen diameter before and after training and after detraining. The before-training baPWV did not differ significantly among the three groups. After 8 weeks of RT, arterial stiffness in the CRT group was increased compared with the ERT and SED group (P<0.05). However, brachial blood pressure, baPWV, carotid IMT and carotid lumen diameter in the ERT and CRT groups were unchanged by RT for 8 weeks. Consequently, it was clarified that arterial stiffness was not changed by ERT for 8 weeks. This suggests that ERT may be effective as an exercise prescription for middle-aged and elderly adults.

Enhancement of antitumor activity of herpes simplex virus gamma(1)34.5-deficient mutant for oral squamous cell carcinoma cells by hexamethylene bisacetamide

Current oncolytic viruses exert only limited antitumor activity on their own. There is a need to increase their oncolytic capability. We evaluated the effect of a differentiating reagent, hexamethylene bisacetamide (HMBA), on the antitumor activity of a gamma(1)34.5-deficient herpes simplex virus type 1 (HSV-1) R849 for human oral squamous cell carcinoma (SCC) cells. Hexamethylene bisacetamide increased the viral yield, especially at a low input multiplicity of infection (MOI), and the transcription of immediate early genes of HSV-1. Hexamethylene bisacetamide treatment promoted the cytopathic effect of R849 and increased the proportion of dead cells. Hexamethylene bisacetamide produced more apoptotic cells in R849-infected cells as compared with parental HSV-1(F)-infected cells. The growth of oral SCC xenografts in nude mice was markedly suppressed by treatment with R849 in combination with HMBA, and the survival of the co-treated animals was significantly prolonged as compared with that of animals treated with R849 only. Herpes simplex virus type 1 mRNA was expressed in tumors and trigeminal neurons, but not in brain, lung, liver, and kidney. These results indicate that HMBA enhances the antitumor activity of R849 through the expression of immediate early genes without increasing its toxicity. Hexamethylene bisacetamide can be used as an enhancing agent for oncolytic therapy with HSV-1 mutants.

A comparative assessment of heavy metal accumulation in soft parts and byssus of mussels from subarctic, temperate, subtropical and tropical marine environments

Existing data on metal concentrations in mussels from subarctic, temperate, subtropical and tropical waters were analyzed using multivariate statistics in order to assess regional variations in metal contamination. Potential errors were reduced by only analyzing data from surveys that employed the same protocols, analytical methodologies and analysts. Factor analysis demonstrated that mussels inhabiting extremely contaminated areas (e.g. from Japanese and Swedish metallurgy sources) could be separated from mussels from other contaminated areas, and that metals such as Cd, Pb, Cu and Zn could be used to identify heavily contaminated samples while Co, Fe, Cr and Ni concentrations were good markers for exposure to inputs from different industrial sources. Furthermore byssus, like soft tissue, selectively and sensitively reflects variations of certain metal concentrations in ambient waters and thus serves as a reliable biomonitor for these contaminants in a variety of coastal and estuarine areas.

Hypertrophy of the posterior longitudinal ligament in the thoracic spine

STUDY DESIGN

This is a case report of a patient with hypertrophy of the posterior longitudinal ligament (HPLL) in the thoracic spine. This patient was followed for 10 years after surgery.

OBJECTIVES

The purpose of this study was to report the long-term outcome of HPLL in the thoracic spine.

SETTING

Department of orthopedic surgery, Hiroshima Red Cross and Atomic-bomb Survivors Hospital, Hiroshima, Japan.

METHODS

A 58-year-old-woman with thoracic HPLL was reported. Magnetic resonance image (MRI) and computed tomography (CT) showed the expanded spinal cord compression from Th4 to Th12 due to HPLL. Anterior decompression and fusion (Th10-12) was performed. Histological findings of the surgical specimens showed thickening of the posterior longitudinal ligament with proliferation of chondroid tissue. The clinical outcome and the radiological findings (CT and MRI) were evaluated 10 years after surgery.

RESULTS

The patient was asymptomatic postoperatively. However, the subsequent CT examination revealed ossification of the previously hypertrophied posterior longitudinal ligament.

CONCLUSIONS

HPLL in the thoracic spine is a rare pathological condition causing myelopathy. The results of this study support the hypothesis that HPLL is one of the prodromal conditions of HPLL.

Heat sensitivity of a SARS-associated coronavirus introduced into plasma products

Background and Objectives  Various measures to inactivate/remove viruses have been implemented for manufacturing plasma‐derived products. Here, we examined the heat inactivation ability of an agent of the severe acute respiratory syndrome (SARS), SARS coronavirus (CoV).

Materials and Methods  The Frankfurt‐1 strain of SARS‐CoV was incorporated in manufacturing processes of several products by using samples collected immediately before liquid heat treatment at 60 °C.

Results  SARS‐CoV was easily inactivated by this treatment for 60 min in all in‐process samples. However, the different composition of the tested samples affected the heat sensitivity of the virus strain: the infectivity of the virus in Antithrombin III preparation still remained after heating for 30 min at 60 °C.

Conclusion  If by rare chance SARS‐CoV contaminates source plasma, there should be no or only minor risk of this virus infection, due to sufficient inactivation by the 60 °C 10 h liquid heating step, although we must pay attention to the composition used for blood product preparation.

Experimental transmission of abnormal prion protein (PrPsc) in the small intestinal epithelial cells of neonatal mice

Using an immunohistochemical method, we attempted to detect the transmission of abnormal prion protein (PrPsc) to the enterocytes of the small intestine of neonatal mice by oral exposure with sheep brain affected by scrapie. Five 1-day-old neonatal mice were exposed by oral inoculation to the homogenized brain of a scrapie-affected sheep. In the small intestine of all mice 1 hour after inoculation, immunoreactivity with antinormal prion protein (PrPc) antibody was seen in the cytoplasm of villus enterocytes. This finding suggests transmission of abnormal PrPsc into the cytoplasm of enterocytes. In control mice treated with normal sheep brain, no PrPc signal was seen in enterocytes of the small intestine. Immunopositivity for neurofilament protein and glial fibrillary acidic protein was seen in the cytoplasm of enterocytes of mice inoculated with scrapie and normal sheep brain. This suggests that the enterocytes of neonatal mice can absorb PrPsc and other macromolecular proteins of the sheep brain affected by scrapie and may be more important than previously thought as a pathway for PrPsc transmission in neonatal animals.

Experimental vertical transmission of Borna disease virus in the mouse

We demonstrated the experimental vertical transmission of Borna disease virus (BDV) in pregnant BALB/c mice. Giessen strain He/80 of BDV was used in the present study. Six six-week-old mice were inoculated intraperitoneally with 10(5) 50% tissue culture infective doses (TCID50), and were bred immediately. Four pregnant mice were sacrificed under anaesthesia on the 10th and 14th days after vaginal plug formation. Nine newborns from two maternal mice were sacrificed under anaesthesia on the 7th day after birth. Positive signals with RT-nested PCR techniques for BDV p24-RNAs were seen in the fetuses, placentas and brains of all newborn mice. No immunopositivities for BDV p40 were found in the fetuses or placentas at 10 days' gestation. BDV p40 immunopositivities were found in neurons of the fetal brains and in decidual cells of the placentas at 14 days' gestation. They were also found in neurons of the brains of newborn mice. At 10 days' gestation, no positive signals for BDV p40 sense or antisense riboprobes were seen in the fetal brains or placentas. Positive signals were found in neurons of the fetal brains and decidual cells of the placentas at 14 days' gestation. Positive signals for BDV p40 sense and antisense riboprobes were found in almost all neurons throughout the brains of nine newborn mice. These results suggest that persistent infection with BDV in newborn mice may be induced by vertical transmission during gestation.

Lack of clinical utility of minimal residual disease detection in allogeneic stem cell recipients with childhood acute lymphoblastic leukemia: multi-institutional collaborative study in Japan

The clinical utility of minimal residual disease (MRD) measurements following allogeneic stem cell transplantation (SCT) in childhood ALL is controversial. We therefore performed a multi-institutional study of MRD in bone marrow samples taken before SCT and at 1, 3, 6 and 12 months after SCT. Case-specific clonal rearrangements of IgH and TCR genes and expression levels of Wilms' tumor 1 (WT1) mRNA were determined by PCR or RT-PCR methods. In total, 95 cases met all criteria for analysis of informative IgH/TCR markers and quantitative WT1 mRNA expression levels. During the 2-year (median 414 days) study period, 20 patients relapsed. Although the proportion of patients with a positive IgH/TCR result before SCT was significantly reduced at 1 month after treatment (P<0.001), attesting the efficacy of SCT, serial measurements of IgH/TCR rearrangements did not correlate with leukemic relapse. Clonal switch was demonstrated in 11 of the 14 patients with bone marrow relapse, indicating that the poor predictive power of the MRD assay most likely reflected the loss of PCR targets. WT1 expression was not related to either MRD detection by IgH/TCR assays or to clinical leukemic relapse. The clinical value of serial MRD monitoring would be limited in ALL patients undergoing SCT.

Heat sensitivity of human parvovirus B19

BACKGROUND AND OBJECTIVES

To date there has been no published report on a systematic evaluation of the heat sensitivity of human parvovirus B19 (B19) and the related safety of the plasma-derived fractionated products. In this study, we examined the heat sensitivity of B19 by using the infectivity assay with cultured cells.

MATERIALS AND METHODS

The heat sensitivity of B19 was examined by measuring the reduction in viral infectivity titres after heating liquid containing B19 at 60 degrees C. Viral infectivity was assayed by detection of viral antigens or viral mRNA in infected cells. As a control, canine parvovirus (CPV) was also heat-treated.

RESULTS

B19 displayed quite different inactivation kinetics to CPV when both were heated in liquid at 60 degrees C. In sharp contrast to the latter, B19 was rapidly inactivated within 1 h when the virus was suspended in 5% or 25% human serum albumin solution, phosphate-buffered saline, or complete medium. However, B19 appeared to be resistant to heat inactivation in liquid containing 60% sucrose.

CONCLUSIONS

The heat sensitivity of B19 in liquid was clearly different from that of CPV. Significantly, the efficiency to inactivate B19 and reduce its infectivity following heating in liquid was mainly affected by the composition of the solutions used for virus suspension.

Split chimerism after allogeneic bone marrow transplantation in Chediak-Higashi syndrome

Chediak-Higashi Syndrome (CHS) is a hereditary multiorgan disease associated with a lymphoproliferative disorder termed 'accelerated phase' (AP). As AP is often life-threatening, hematopoietic stem cell transplantation has been proposed as the only curative treatment for CHS. Here, we report a 1-year-old Japanese boy with CHS who received an HLA-matched unrelated BMT at the AP stage, which resulted in split chimerism. We evaluated the chimerism status of isolated leukocytes and found that only a limited population of T and NK cells was of donor origin and the majority of these and other hematopoietic cells was of host origin. Clinical outcome was successful, and the patient is currently alive and well, free of AP and serious infections more than 18 months after BMT.

Borna disease in a dog in Japan

Borna disease (BD) was diagnosed in a 3-year-old male Welsh corgi suffering from a severe and acute progressive disorder of the central nervous system. Histopathologically, neuronal lesions were characterized by a non-suppurative encephalomyelitis dominated by large perivascular cuffs consisting of lymphocytes, macrophages and plasma cells; also present were inflammatory cell infiltrates in the neural parenchyma, neuronophagia and focal gliosis. Strong immunolabelling with BD virus (BDV) p40 antibody was diffusely distributed in the cytoplasm of small and large neurons in areas of the brain with and without inflammatory changes, and also in the spinal cord. Positive hybridization signals with BDV p40 sense and antisense riboprobes were seen in the nucleus and cytoplasm of the neurons throughout the whole brain and spinal cord. BDV p24 RNA in formalin-fixed brain tissue was detected by reverse transcriptase (RT)-nested polymerase chain reaction (PCR). BDV p24 RNA-positive signals were detected in the temporal lobe. This is the first report of spontaneous canine BD in Japan.