Measurement of B(0)(d)-B_(0)(d) mixing rate from the time evolution of dilepton events at the upsilon(4S)

We report a determination of the B(0)(d)-&B_(0)(d) mixing parameter Deltam(d) based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 fb(-1) data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Deltam(d) as a free parameter. Using both muons and electrons, we obtain Deltam(d) = 0.463+/-0.008 (stat)+/-0.016 (syst) ps(-1). This is the first determination of Deltam(d) from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.

Measurement of the CP violation parameter sin2 phi(1) in B(0)(d) meson decays

We present a measurement of the standard model CP violation parameter sin2 phi(1) (also known as sin2beta) based on a 10.5 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) collider. One neutral B meson is reconstructed in the J/psiK(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psiK(L), or J/psipi(0) CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine sin2 phi(1) = 0.58(+0.32)(-0.34)(stat)+0.09-0.10(syst).

Mother-to-infant transmission of GB virus type C/HGV

BACKGROUND

The potentially hepatotropic flavivirus-like virus, GB virus type C (GBV-C)/HGV, has been detected in a few patients with acute and chronic hepatitis and in a certain proportion of blood donors and recipients of blood or blood components.

STUDY DESIGN AND METHODS

Sera from 2979 pregnant Japanese women were examined for the presence of GBV-C/HGV RNA by nested RT-PCR. Mothers who were positive for viral RNA and their 34 infants were followed and tested for infection.

RESULTS

Of the 2979 women, 32 (1.1%) were positive for GBV-C/HGV RNA. Twenty-six (76.5%) of 34 babies born to these women were positive for the virus when first tested. A significantly higher titer of viral RNA was observed in mothers whose infants were infected than in those whose infants were uninfected (mean +/- SD, 10(6.3 +/- 0.9) vs. 10(4.6 +/- 0.9)/mL; p<0.001). Twenty-three (96%) of 24 babies born to mothers whose serum viral titers were 10(6) mL or more were infected with the virus. Infants delivered by elective caesarean section had a lower risk (OR, 0.13; 95% CI, 0.02-0.82) than those delivered vaginally or by emergency caesarean section. No other risk factors for mother-to-infant transmission were confirmed.

CONCLUSIONS

GBV-C/HGV is frequently transmitted from mothers to infants in the general population. The most critical factor is the titer of viral RNA in the maternal serum. By the use of elective caesarean section in women with high titers of viral RNA, vertical transmission of the virus may be lessened.

Prenatal diagnosis of intrapericardial teratoma: a case report

A hydropic fetus that exhibited intrapericardial teratoma with marked pericardial effusion was prenatally diagnosed. Intrauterine pericardiocentesis was performed to diagnose and to treat hydrops. Pericardiocentesis for tamponade secondary to a fetal intrapericardial teratoma might prevent fetal death and premature delivery.

Lack of difference in cytomegalovirus transmission via the transfusion of filtered-irradiated and nonfiltered-irradiated blood to newborn infants in an endemic area

BACKGROUND

It is accepted that white cells contained in blood components are the most significant source of cytomegalovirus (CMV) infection in immunocompromised and immunodeficient recipients.

STUDY DESIGN AND METHODS

To determine whether white cell filtration of blood would be effective in preventing infection among newborn transfusion recipients in a hyperendemic area, a randomized study was performed. All donor blood units were irradiated before issue to prevent posttransfusion graft-versus-host disease. Recipients were monitored for CMV infection by seroconversion (development of IgM anti-CMV) and CMV-DNA isolation.

RESULTS

Three (9%) of 33 infants who received filtered blood and 1 (5%) of 19 infants given nonfiltered blood were infected with CMV, as determined by the presence of IgM anti-CMV and/or CMV DNA isolation.There was no significant difference in the rate of CMV infection in the two groups.

CONCLUSION

The CMV infection observed in the study may come from other routes such as breastfeeding, rather than from transfusion. Our findings suggest that the routine use of white cell-reduction filtration to reduce the risk of transmitting CMV is unwarranted for neonates in endemic regions.

[Cytomegalovirus transmission through blood transfusion to newborn recipients]

Premature newborns, who are at risk if infected with cytomegalovirus (CMV), has been recommended to receive blood from seronegative donors or leukocyte-reduced blood. The lower CMV infection rate seen in later studies is associated with the decreased use of fresh blood. One of the most significant risk factors of the infection is the use of fresh blood. CMV infection rate of filtered-irradiated blood newborn recipients in our prospective study did not differ from non-filtered and irradiated blood recipients. Gamma-irradiated blood is analog to leukodepleted blood in terms of abolished capability of immune response, even though the former contains adequate number of leukocyts. Mixed lymphocytes reaction of donor's lymphocyte plays a pivotal role in transmission of CMV from seropositive donors to recipients. It is likely that some newborns with post-transfusion graft-versus-host disease were misdiagnosed as transfusion-acquired CMV disease, as often overlap later CMV infection due to profound agranulocytosis. We hypothesize that donor lymphocytes abolished proliferating function by irradiation, storage or filtration are no more possible to evoke reaction against recipient's antigen and thus fail to transmit CMV from infected donor to recipient.

Transmission of hepatitis C virus from mothers to infants. The Vertical Transmission of Hepatitis C Virus Collaborative Study Group

BACKGROUND

Although there are case reports of vertical transmission of hepatitis C virus (HCV), it remains uncertain to what extent infected mothers transmit this virus to their infants.

METHODS

We investigated the transmission of HCV from infected mothers to their babies by analyzing HCV RNA in the blood. Three independent studies were performed. First, 7698 parturient women were tested for anti-HCV antibodies; 53 were positive. Their 54 infants (including one set of twins) were followed prospectively for at least six months and tested for HCV disease were prospectively studied. Third, the families of three HCV-infected infants were examined retrospectively.

RESULTS

Of the 53 antibody-positive mothers, 31 were also positive for serum HCV RNA: Three of the 54 babies born to these mothers (5.6 percent) became positive for HCV RNA during the follow-up period. None of the babies of the 22 women who were antibody-positive but HCV RNA-negative became positive for HCV RNA: In the second study, HCV RNA was detected in one of the six infants of infected mothers. In the third study, HCV RNA was detected in the mothers of the three HCV-infected infants. In each of the seven infected infants we studied, the genomic sequence of HCV was almost identical to that from the mother. These seven mothers had significantly higher titers of HCV RNA than did the mothers of infants with no evidence of infection (mean [+/- SD], 10(6.4 +/- 0.5) vs. 10(4.4 +/- 1.5) per milliliter; P < 0.001).

CONCLUSIONS

HCV is vertically transmitted from mother to infant, and the risk of transmission is correlated with the titer of HCV RNA in the mother.