95 DEVELOPMENT OF PORCINE TWO-CELL EMBRYOS WITH OR WITHOUT ZONA PELLUCIDA AND SINGLE BLASTOMERES

In the mouse, single blastomeres of the 2-cell embryos can develop into adult mice and occasionally both separated blastomeres can give rise to twin animals (reviewed by Tarkowski AK et al. 2001 Int. J. Dev. Biol. 45, 591–596). As a preliminary study for production of monozygotic twins from porcine 2-cell embryos, we investigated the effects of removal of zona pellucida and blastomere isolation at the 2-cell stage on subsequent development of parthenogenetic embryos. Oocytes with the first polar body were parthenogenetically activated after 44 h of in vitro maturation. Stimulated oocytes were then incubated in IVC-PyrLac (IVC medium with pyruvate and lactose) according to the method reported by Kikuchi K et al. (2002 Biol. Reprod. 66, 1033–1041). After 24 to 30 h of parthenogenetic activation, equally cleaved 2-cell embryos were selected and used for the experiments. Some 2-cell embryos were then treated with pronase to remove the zona pellucida and cultured individually as zona-free 2-cell embryos having 2 blastomeres in pair (ZF group), and single blastomeres were split from ZF group and cultured separately (SB group) in V-shaped microwells. In addition, intact 2-cell embryos were cultured individually without pronase treatment as a control group. After 24 h of in vitro culture, IVC-PyrLac was replaced by IVC-Glu (IVC with glucose). The blastocyst rates on Day 6 (Day 0 was defined as the day of electrical stimulation) in control, ZF, and SB groups did not differ (47.6, 50.0, and 42.1%, respectively). Nevertheless, blastocysts derived from the ZF (28.6 ± 3.0) and SB groups (25.9 ± 1.3) had a significantly lower total cell number than that of the control group (41.7 ± 3.2; P < 0.01 by ANOVA). Although the total cell number of blastocysts originating from single blastomeres was significantly lower than that in the intact embryos, the blastocyst formation rates were not different between them. This indicated the possibility of production of monozygotic twins from porcine 2-cell embryos divided into 2 single blastomeres. However, further research is needed to improve blastocyst quality descended from single blastomeres. In conclusion, the removal of the zona pellucida had a negative influence on blastocyst quality but did not affect the development of porcine embryos to the blastocyst stage.

90 GERM-LINE TRANSMISSION OF DONOR MITOCHONDRIAL DNA IN NUCLEAR TRANSFER-DERIVED COWS

In embryos derived by nuclear transfer (NT), fusion, or injection of donor cells with recipient oocytes caused mitochondrial heteroplasmy. Previous studies have reported varying patterns of mitochondrial DNA (mtDNA) transmission in cloned calves. Distribution of donor mtDNA found in offspring of NT-derived founders may also vary from donor–host embryo heteroplasmy to host embryo homoplasmy. Here we examined the transmission of mtDNA from NT cows to their progeny. NT cows were originally produced by fusion of enucleated oocytes with Jersey (J) or Holstein (H1) oviduct epithelial cells, or Holstein (H2) or Japanese Black (B) cumulus cells, as previously reported (Goto et al. 1999 Anim. Sci. J. 70, 243–245; Yonai et al. 2005 J. Dairy Sci. 88, 4097–4110; Akagi et al. 2003 Mol. Reprod. Dev. 66, 264–272). Transmission of donor cell mtDNA was analyzed by PCR-mediated single-strand conformation polymorphism (PCR-SSCP) analysis of the mitochondrial D-loop region. Eleven NT founder cows were analyzed, 4 (2 = J-NT, and 2 = H1-NT) of them were heteroplasmic whereas 7 (1 = J-NT, 1 = H1-NT, 2 = H2-NT, and 3 = B-NT) were homoplasmic for the host embryo mitochondria. The proportions of donor mtDNA detected in one J-NT cow was 7.7%, and those of other cow lineages were &lt;2%. Heteroplasmic NT cows delivered a total of 9 progeny. Four of the 9 progeny exhibited heteroplasmy with high percentages of donor cell mtDNA populations (52%, 37%, 17%, and 43%). The other 5 progeny were obtained from heteroplasmic NT cows, and all samples of the 10 progeny obtained from the homoplasmic NT cows did not harbor detectable donor cell mtDNA. A genetic bottleneck in the female germ-line will generally favor the transmission of a single mitochondrial population, leading to a return to homoplasmy. Thus, some of progeny maintained heteroplasmy with a higher ratio than that of their NT mothers, which may also reflect a segregation distortion caused by the proposed mitochondrial bottleneck. These results demonstrated that donor mtDNA in NT cows could be transmitted to progeny with varying efficiencies, in a lineage-specific fashion.

97 CLONED CALF PRODUCTION BY AGGREGATION OF SOMATIC CELL NUCLEAR-TRANSFERRED EMBRYOS

A low pregnancy rate and high frequency of abortion are observed in bovine somatic cell cloning. It is suggested that one of the factors is the low cell number of nuclear-transferred (NT) embryos at the blastocyst stage compared with that of in vivo-derived embryos. We reported that aggregation of bovine NT embryos can develop to blastocysts with cell numbers that are equivalent to in vivo-derived embryos (Akagi et al. 2005 Reprod. Fertil. Dev. 17, 162 abst). In this study, we examined the in vivo development of aggregates of NT embryos after embryo transfer (ET). Following culture in serum-starved medium for 5 to 7 days, fibroblast cells were used as donor cells for NT. NT was performed as previously described (Akagi et al. 2003 Mol. Reprod. Dev. 66, 264–272). Eight-cell stage embryos on Day 2 or 16- to 32-cell stage embryos on Day 4 were used for embryo aggregation after removal of the zona pellucida. Three NT embryos were placed into the depression in a drop of TCM-199 with 50 µg mL−1 phytohemagglutinin for 20 min, and NT aggregates were then moved into the depression in a drop of IVD-101 (Akagi et al. 2005). On Day 7 after NT, ET was performed nonsurgically. Results are summarized in Table 1. Pregnancy rates obtained with the aggregated NT embryos tended to be high compared with the single NT embryos. All pregnant cows in the single NT embryos and 6 of 8 pregnant cows in the aggregated NT embryos were aborted within 90 days. One cow carrying an aggregate of 3 Day 2 NT embryos went to term, and one carrying an aggregate of 3 Day 4 NT embryos is still pregnant at more than 7 months. These results demonstrate that aggregates of 3 NT embryos can develop to term in cattle. Table 1.In vivo development of aggregated NT embryos

24 EFFECT OF TREATMENT WITH TRICHOSTATIN A ON IN VITRO DEVELOPMENT OF BOVINE NUCLEAR-TRANSFERRED EMBRYOS

It has been reported that 5 or 50 nM trichostatin A (TSA) treatment after somatic cell nuclear transfer (NT) improves the success rate of mouse cloning (Kishigami et al. 2006 Biochem. Biophys. Res. Commun. 340, 183–189). In this study, we examined the effect of TSA treatment on the in vitro development of bovine NT embryos. As donor cells for NT, bovine fibroblast cells of passages 3 to 5 were used following culture in serum-starved medium for 5 to 7 days. Oocytes were enucleated after in vitro maturation in TCM-199 supplemented with 10% fetal bovine serum. Enucleated MII oocytes were fused with fibroblast cells by a DC pulse of 25 V/150 µm for 10 µs in Zimmerman mammalian cell fusion medium. Fused oocytes were activated by 10 µM calcium ionophore for 5 min, followed by incubation with 2.5 µg mL−1 cytochalasin D, 10 µg mL−1 cycloheximide, and 5 or 50 nM TSA for 1 h, and then cycloheximide and 5 or 50 nM TSA for 4 h. After chemical activation, NT embryos were cultured in IVD-101 (Research Institute of Functional Peptide Co., Ltd., Yamagata, Japan) with 5 or 50 nM TSA for 10 h and subsequently cultured in IVD-101 without TSA. Control NT embryos were cultured in the same medium without TSA after fusion. After in vitro culture for 8 days, blastocyst formation and cell numbers of blastocysts were examined. The fusion rate of enucleated oocytes with fibroblast cells was 81% (199/247). In vitro development of NT embryos is summarized in Table 1. There were no differences in the cleavage rate and development rate to the blastocyst stage of NT embryos among control, and 5 and 50 nM TSA treatments. The cell number of 50 nM TSA-treated NT embryos at the blastocyst stage was higher than that of control NT embryos without TSA treatment. In conclusion, 50 nM TSA treatment for 15 h after activation did not affect the in vitro developmental competence, but increased total cell number in bovine NT embryos. These results suggest that TSA treatment may improve the quality of blastocysts in bovine NT. Table 1. Effects of TSA treatment on in vitro development of NT embryos derived from fibroblast cells

39 BOVINE SOMATIC CELL NUCLEAR TRANSFER USING CUMULUS - OOCYTE COMPLEXES COLLECTED FROM THE IDENTICAL INDIVIDUAL BY OVUM PICKUP

We previously produced a cloned calf by nuclear transfer (NT) using cumulus cells removed from cumulus–oocyte complexes (COCs) after IVM. If both cumulus cells and oocytes are obtained identically and individually, and can be used simultaneously for NT, the production of cloned cows will be more expedient. And the cloned offspring produced from them will not exhibit the heteroplasmic mixed mtDNAs of donor cells and recipient oocytes. In this study, we examined the developmental potential of NT embryos using cumulus–oocyte complexes (COCs) collected from cows individually by ovum pickup (OPU). The cumulus cells were removed from COCs after IVM. The cumulus cells and cumulus-free MII oocytes derived from the same cow were used as donor nuclei and recipient oocytes, respectively. NT was performed as previously described (Akagi et al. 2003 Clon Stem Cells 5, 101–108). In Experiment 1, we examined the in vitro development of NT embryos using COCs collected by OPU. The aspiration of the follicles was performed once a week consecutively for 6 weeks in 6 cows (Cows A, B, C, D, E, and F) without hormone stimulation. In Experiment 2, we examined fetal development after the transfer of NT embryos. A Japanese black cow (Cow G) was used for OPU. On Day 7, 13 NT blastocysts were transferred to 7 recipient cows. The mtDNA genotypes of the donor cow and the cloned calf were analyzed by PCR-mediated single-strand conformation polymorphism analysis as previously described (Takeda et al. 2003 Mol. Reprod. Dev. 64, 429–437). The results of Experiment 1 are summarized in Table 1. Fusion rates did not differ among individual cows. However, the developmental rates of NT embryos at the blastocyst stage varied widely among individual cows, with a range of 19 to 64%. In Experiment 2, 2 of 7 recipient cows became pregnant on Day 30. One pregnant cow aborted on Day 60, and another cow calved a healthy calf. The mtDNA genotype of the cloned calf was confirmed to be identical with that of the donor cow. These results indicate that COCs from an identical individual can be used as donor nuclei and recipient oocytes for NT in order to produce female clones with the same mtDNA as that of the donor cow. Table 1.In vitro development of NT embryos using COCs collected by OPU

233 TEMPOROSPATIAL EXPRESSION PROFILES OF GROWTH AND DIFFERENTIATION FACTOR-9 AND BONE MORPHOGENETIC PROTEIN-15 GENES IN THE BOVINE OVARY

Bone morphogenetic protein (BMP) family proteins regulate the folliculogenesis and ovulation rate in mammals. Of the members of BMP family, growth and differentiation factor-9 (GDF-9) and BMP-15 are oocyte-derived proteins that play critical roles in follicular development. In the present study, we characterized the temporospatial expression patterns of GDF-9 and BMP-15 in bovine ovaries. Bovine ovaries were obtained from local abattoir. Cumulus–oocyte complexes (COCs) and mural granulosa cells were collected by aspiration of follicles 2–5 mm in diameter. Follicular aspiration was done the day following slaughter. The COC and mural glanulosa cells were separated and cultured for 20 h according to the protocol for oocyte maturation. Total RNA was isolated from COCs, cumulus cells, denuded oocytes, and mural granulosa cells and used for PCR. For in situ hybridization, collected ovaries were immediately fixed with 4% formaldehyde-PBS and embedded in a paraffin block. In situ hybridization was carried out with digoxigenin-labeled probes. In COCs and cumulus cells, the transcripts encoding GDF-9 and BMP-15 were detected immediately after follicular aspiration and still remained at the end of maturation culture. However, in mural granulosa cells, only GDF-9 expression was detected. Germ cell/oocyte markers, ZAR1 and VASA, were not detected in cumulus and mural granulosa cells. Quantitative real-time RT-PCR revealed extensive expressions of both GDF-9 and BMP-15 in oocytes. In situ hybridization study showed that GDF-9 and BMP-15 were co-localized to oocytes in primary, secondary, and antral follicles. The ovular co-expression of GDF-9 and BMP-15 appeared to commence at fetal life. Expression of GDF-9 and BMP-15 was not clear in cumulus cells possibly because of low expression level. In conclusion, our results show that GDF-9 and BMP-15 are co-localized to oocytes from an early stage of folliculogenesis. Since the transcripts encoding GDF-9 and BMP-15 are detected in cumulus cells, it is suggested that the oocyte is not the sole source of them. Additionally, the cumulus and mural granulosa cells are suggested to be functionally differentiated relative to BMP-15 expression.

Brown-Séquard-plus syndrome due to stab injury: a case report

STUDY DESIGN

Case report.

OBJECTIVE

To describe the mechanism of injury in this case and its clinical features. Magnetic resonance (MR) images of hemorrhage in spinal cord injury due to stab wound are discussed.

METHODS

We describe the case of a 21-year-old woman who was stabbed in the right side of her neck and developed left-sided Brown-Séquard syndrome plus loss of bilateral proprioceptive sensation. Neither plain radiographs nor computed tomography of the cervical spine demonstrated any foreign bodies or fractures of the cervical spine. T2-weighted cervical MR images confirm spinal cord hemiresection at C5-C6.

RESULTS

MR imaging was performed serially at 4 days, 4 weeks, and 8 weeks after trauma. The signal pattern of the spinal cord at the site of injury varied iso, iso, and low on T1-weighted consecutive images. Meanwhile, high signal intensity on T2-weighted images was consistent during the 8 weeks after incidence of trauma. A T2-weighted sagittal image showed a tiny spot of low intensity in the high signal band at the site of penetration, demonstrating hemosiderin formation in the spinal cord. The patient was treated conservatively and, recovered from Frankel grade C to grade D.

CONCLUSION

Spinal cord injuries (SCI) following stab wounds are rare. MR imaging is definitely useful for recording and monitoring the pathology of SCI.

25 IN VITRO DEVELOPMENT OF AGGREGATED NUCLEAR TRANSFERRED EMBRYOS DERIVED FROM BOVINE CUMULUS CELLS

It has been reported that aggregation of two nuclear transfer (NT) mouse embryos shows an improvement in full-term development (Boiani M et al. 2003 EMBO J. 22, 5304–5312). In this study, we examined the effect of aggregation on in vitro development of bovine NT embryos. As donor cells for NT, cumulus cells of passage 3–5 were used following culture in serum-starved medium for 5–7 days. NT was performed as previously described (Akagi S et al. 2003 Mol. Reprod. Dev. 66, 264–272). NT embryos were cultured in a serum-free medium (IVD-101, Research Institute of Functional Peptide Co., Ltd., Shimojo, Yamagat, Japan). Eight-cell-stage embryos on Day 2 or 16- to 32-cell-stage embryos on day 4 were used for embryo aggregation after removal of the zona pellucida. A small depression was made in a 25-μL drop of TCM-199 with 50 μg/mL phytohemagglutinin (TCM199/PHA) or IVD-101 using a darning needle. Two or three NT embryos were placed into the depression in the drop of TCM199/PHA for 20 min. NT aggregates were then moved into the depression in the drop of IVD-101 and cultured until Day 7. In vitro development of NT aggregates was summarized in Table 1. There were no differences in the cell number and ICM ratio of blastocysts between non-aggregated zona-intact and zona-free embryos. All aggregates of three NT embryos developed to the blastocyst stage and the cell number of these blastocysts was significantly higher than that of non-aggregated NT blastocysts. These results indicate that removal of the zona pellucida does not affect the cell number and ICM ratio of blastocysts and that aggregates of three NT embryos can develop to blastocysts with high cell numbers which are equivalent to in vivo-derived embryos (166 ± 11, Knijn HM et al. 2003 Biol. Reprod. 69, 1371–1378). Table 1. Development, cell number, and ICM ratio of NT aggregates

Effects of re-immunization of heifers against inhibin on hormonal profiles and ovulation rate

To study the effect of re-immunization against inhibin on ovarian response and hormonal profiles, Japanese beef heifers (n = 5) were re-immunized three times with inhibin vaccine (recombinant ovine inhibin α-subunit in oil emulsion, 125 μg ml−1) one year after the primary immunization. Control heifers (n = 5) were injected with placebo (Montanide: Marcol adjuvant alone). Oestrous cycles were synchronized by using prostaglandin F2α (PGF2α) and ovarian response was monitored daily by ultrasonography. Blood samples were collected by jugular venipuncture for assessment of hormonal levels and inhibin antibody titres. In contrast to controls, inhibin re-immunized heifers generated antibodies against inhibin rapidly reaching a peak level 9 days after the first booster injection. The mean concentrations of FSH in re-immunized cows increased significantly in comparison with controls. In addition, there was a significant increase in oestradiol-17β and progesterone levels in re-immunized cows compared with controls. Inhibin re-immunized heifers had a significant increase in small (≥4 < 7 mm), medium (≥7 < 10 mm) and large (≥10 mm in diameter) sized follicles. Moreover, the mean ovulation rate was 5.0 ± 1.1 after the third booster injection in re-immunized heifers compared with control heifers (single ovulation). These results clearly demonstrate that re-immunization of inhibin can be used to enhance ovarian follicular development and ovulation rate. Furthermore, the great number of follicles is a potential source of oocytes that could be harvested for in vitro fertilization and embryo transfer programmes.

Threonine metabolism in Japanese quail liver

In general, threonine is metabolized by reaction catalyzed by threonine-3-dehydrogenase (TDH), threonine dehydratase (TH) or threonine aldolase (TA). The activities of these three enzymes were compared in the liver of Japanese quails and rats. The animals were fed a standard or threonine rich-diet, or fasted for 3 days. The specific activity of TDH in the liver from quail fed a standard diet was 11 times higher than that in the liver from rats fed a standard diet. The TDH activities in the livers of the fasting and 5% threonine-rich diet groups of quail were 3 and 2 times higher than those in the livers from quail fed the standard diet, respectively. The TH activity in the liver of rats fed a standard diet was 14 times higher than that in the liver of quail fed a standard diet. The TH activity in the rat liver after fasting was 2.3 times higher than that of the standard diet control. The activity of TA in the livers of rat and quail were so low that its role in threonine metabolism in both animals seemed to be negligible. These results suggest that threonine is a ketogenic amino acid in the quail liver, while it is a glucogenic in the rat liver.

Threonine is the best substrate for D-lactate formation in octopus tentacle

Carbon sources for D-lactate and enzyme activities related to D-lactate formation were investigated using cell-free homogenates of Octopus vulgaris tentacle tissue. The results are as follows: a) The best precursor for D-lactate formation was threonine and second best precursors were glycine and fructose-1,6-bisphosphate. Threonine and glycine served as precursors only in presence of glutathione. b) Both amino acids were precursors for methylglyoxal from which D-lactate was synthesized. Alanine, cysteine and serine were not precursors. We present a metabolic map for D-lactate formation in octopus in order to explain these experimental results.

Gut transit time after ileal pouch-anal anastomosis using a radiopaque marker

PURPOSE

The aim of this study was to determine the contribution of gastrointestinal motility to bowel function and the pathogenesis of pouchitis after ileal pouch-anal anastomosis.

METHODS

Gastrointestinal transit time was assessed by a radiopaque marker technique in 32 patients with ulcerative colitis.

RESULTS

Small intestinal transit time and pouch emptying time were 4.1 +/- 2 hours and 4.1 +/- 2.5 hours, respectively. There was no significant difference in pouch emptying time between patients with and without pouchitis. When only patients with acute pouchitis that responded to metronidazole were analyzed, there was a trend toward a prolonged pouch emptying time compared with those without pouchitis (P = 0.095). Whole gut transit time was inversely correlated with 24-hour stool frequency in patients without pouchitis (r = -0.63, P < 0.005). In the analysis of regional transit time, only small intestinal transit time was inversely correlated with 24-hour stool frequency (r = -0.472, P < 0.05). Significant prolongation of small intestinal transit time was demonstrated in patients over a period of 41 months (the median time) after ileostomy closure compared with those whose pouches had been functioning for 6 to 41 months (5.4 +/- 1.7 hours vs. 3.1 +/- 1.3 hours, P < 0.005).

CONCLUSIONS

There was an association between small intestinal motility and bowel frequency. Further investigation is necessary in the pathogenesis of acute pouchitis regarding the relationship between delayed pouch emptying and subsequent development of mucosal inflammation.

Relationships of serum levels of insulinlike growth factors with indices of bone metabolism and nutritional conditions in hemodialysis patients

Insulinlike growth factor (IGF) I and IGF-II are synthesized in osteoblasts and stimulate proliferation, differentiation, and matrix synthesis in these cells. There is some evidence that IGFs act on bone cells not only by paracrine but also by endocrine pathways, suggesting that circulating IGFs may be of importance for the regulation of bone metabolism. On the other hand, the serum IGF-I level is also thought to be a good indicator of the nutritional conditions in hemodialysis patients. The present study was performed to analyze the correlations of circulating levels of IGF-I, IGF-II, IGF-binding protein (IGFBP) 1 and IGFBP-3 with biochemical markers of bone metabolism and parameters of the urea kinetic model which reflect nutritional conditions in hemodialysis patients. We also examined the differences between these relationships in male and female patients on hemodialysis. Sixty-two hemodialysis patients, 36 men (male group) and 26 women (female group), were included in this study. We measured the serum levels of IGF-I, IGF-II, IGFBP-1, and IGFBP-3. The bone mineral content (BMC) of the radius was measured by dual-energy X-ray absorptiometry. We calculated Kt/V, protein catabolic rate, and percent creatinine generation rate (%CGR). We also examined the relationships between serum levels of IGFs and BMC and the parameters of the urea kinetic model. It was found that the serum levels of IGF-I in the hemodialysis patients were almost the same as those in the control group. However, the serum levels of IGF-II, IGFBP-1, and IGFBP-3 in the hemodialysis patients were significantly higher than those in the control group. In the male group, the serum IGF-I levels showed a significant correlation with both serum intact parathyroid hormone levels and BMC, but no significant correlations between these indices were found in the female group. The serum levels of both IGF-I and IGF-II showed significant correlations with %CGR in the male group, but not in the female group. Stepwise multiple regression analysis was performed to clarify the relationship between serum levels of IGFs and BMC or %CGR. It was found that age, hemodialysis duration, serum intact parathyroid hormone levels, and sex were independent factors associated with BMC. The %CGR was associated independently with serum levels of IGF-I, and IGF-II and with the presence of diabetes mellitus. In conclusion, it is thought that serum levels of IGF-I and IGF-II can be used as indices of nutritional conditions in hemodialysis patients. However, the serum IGF-I level cannot be used as a marker of bone metabolism in hemodialysis patients.

Plasma adrenomedullin levels in patients on hemodialysis

Adrenomedullin (AM) is a hypotensive peptide that has recently been isolated from human pheochromocytoma. In this study, we measured plasma AM concentrations in 54 patients on hemodialysis (HD) and examined the clinical significance. We also evaluated the effects of high-flux and low-flux dialysis membranes on plasma AM levels. The average value of plasma AM at pre-HD (4.44 +/- 0.16 fmol/ml) was significantly elevated compared with that in 44 healthy volunteers (1.31 +/- 1.41 fmol/ml) (p < 0.0001). The plasma AM concentrations at pre-HD showed a negative correlation with age and mean blood pressure (MBP) at pre-HD. The plasma AM concentrations at post-HD showed a negative correlation with MBP at post-HD and a negative correlation with the reduction rate of AM. Multiple regression analysis showed that age and MBP were independent factors associated with plasma AM at pre-HD and that MBP and reduction rate of AM were independent factors associated with plasma AM at post-HD. We investigated the differences between high-flux dialyzers (PS-UW, PS-N and FB-F) and a low-flux dialyzer (AM-BC-F), and we found that high-flux dialyzers removed plasma AM more efficiently than a low-flux dialyzer did. In addition, in 3 patients on HD, plasma AM levels decreased significantly during isovolumic dialysis using a high-flux dialyzer, despite the fact that there were no significant changes in MBP and ANP. In conclusion, elevation in plasma AM level causes a fall in MBP in patients on HD, therefore, removal of AM by HD treatment using a high-flux dialyzer contributes to the stability of blood pressure during HD.

Clinical relevance of precore and basal core promoter variants of hepatitis B virus during natural hepatitis B e antigen seroconversion may be overstated

BACKGROUND

Clinical relevance of nucleotide changes in precore and basal core promoters in the hepatitis B virus genome during hepatitis B e antigen seroconversion may be overstated. The authors investigated the existence and changes in the relative proportion of variants to wild virus that occur with seroconversion.

METHODS

Sera from 30 school-aged long-term hepatitis B virus carriers, including 11 tested before and after seroconversion during 1 to 8 years of follow-up, were evaluated for variations in nucleotide sequences of the basal core promoter (T1762 and A1764), precore region (A1869), and carboxyl-terminus of the X region of the hepatitis B virus genome using an amplification refractory mutation detection system with mutant-specific primers.

RESULTS

All variants were found to already exist before seroconversion at various wild-type/mutant ratios. The positive rates of these variants were not changed with loss of hepatitis B e antigen. Although there was a relative increase in the concentration of these mutants in wild-type/mutant mixed populations, most patients with only a wild-type population maintained the same pattern after loss of hepatitis B e antigen.

CONCLUSIONS

Our results indicate that hepatitis B virus exists as a quasi species, and correlations of nucleotide sequences with clinical and serologic findings must be done with caution.

Production and endocrine role of inhibin during the early development of bull calves

This study investigated the ontogeny of control of FSH secretion by inhibin during early prepubertal development of bulls by 1) measurements of circulating levels of inhibin and FSH from 1 to 13 wk of age, and 2) immunoneutralization of endogenous inhibin at 7, 21, 60, and 120 days of age. In addition, production and localization of inhibin in testes were examined by immunohistochemistry and Western blots at 7, 21, 60, and 120 days of age. Plasma immunoreactive inhibin levels were relatively low between 1 and 3 wk of age and then showed a tendency to rise (P < 0.1) from 4 wk of age. Circulating concentrations of FSH were low during 3 wk after birth and increased at 5 wk, remained high (P < 0.05) until 16 wk of age. Treatment with inhibin antiserum resulted in a significant (P < 0.05) increase in plasma FSH at 7, 21, 60, and 120 days of age compared to those following injection of control serum; however, the magnitude of the FSH rise after inhibin immunization was greater as bulls aged. There were no significant changes in plasma LH after inhibin immunization. An intense staining of inhibin alpha subunits was found in Sertoli cells within the solid seminiferous cords from 7 to 120 days of age, while no specific immune reaction was found in interstitial cells. Western blot analysis of testicular homogenates isolated from bulls 7-120 days of age revealed presence of a 28.5-kDa molecule that cross-reacted with inhibin alpha subunit and beta(B) subunit-specific antibodies. In this study, before 13 wk of age in bull calves, there was no inverse relationship between plasma concentrations of immunoreactive inhibin and FSH. However, the present immunization study clearly indicates that inhibin participates in the regulation of FSH secretion from infancy to early prepubertal stage, although the endocrine significance of inhibin becomes greater in older bulls. The results also indicate that the major production site of inhibin in the testis is Sertoli cells and that these cells produce inhibin that exerts a negative feedback effect on FSH secretion from early stages of development.

Sclerosing cholangitis and systemic lymphadenopathy

A 48-year-old man was admitted to our hospital with jaundice and systemic lymphadenopathy. Cholangiographic findings and liver histology disclosed the presence of sclerosing cholangitis. The patient also had a marked polyclonal increase in IgG levels. The cholangiographic findings, the systemic lymphadenopathy, and the increase in IgG levels resolved completely after treatment with prednisolone. This case suggests that there is an association between sclerosing cholangitis and immunologic abnormalities, and that corticosteroid treatment is useful for this disorder.

Co-infection by serologically-silent hepatitis B virus may contribute to poor interferon response in patients with chronic hepatitis C by down-regulation of type-I interferon receptor gene expression in the liver

Intrahepatic mRNA levels of type-I interferon (IFN) receptor genes have been shown to correlate with the clinical efficacy of IFN therapy in patients with chronic hepatitis C. Recently, co-infection by serologically-silent hepatitis B virus (HBV) has been assumed to be associated with the poor IFN response in patients with chronic hepatitis C. The aim of this study was to investigate the relationship between the co-infection of serologically-silent HBV and type-I IFN receptor gene expression in the liver of patients with chronic hepatitis C. The intrahepatic mRNA levels of IFNAR2, one of the two subunits of the type-I IFN receptor, were quantified and compared with both the prevalence of HBV DNA and the hepatitis C virus (HCV) genotype in 45 patients with chronic hepatitis C, who were negative for hepatitis B surface antigen. Co-infection, as evaluated by a nested polymerase chain reaction, was present in 22 patients (48.9%), with dominance of the HCV genotype 1b (65.2%) over genotype 2a (31.8%). Co-infection was associated with lower IFNAR2 mRNA levels, higher levels of serum HCV RNA, and a poor IFN response, regardless of the HCV genotype. The findings suggest the possibility that co-infection by serologically-silent HBV is one of the factors that can lead to an unfavorable IFN response in chronic hepatitis C by down-regulation of IFN receptor gene expression in the liver.

Co-infection by serologically-silent hepatitis B virus may contribute to poor interferon response in patients with chronic hepatitis C by down-regulation of type-I interferon receptor gene expression in the liver

Intrahepatic mRNA levels of type-I interferon (IFN) receptor genes have been shown to correlate with the clinical efficacy of IFN therapy in patients with chronic hepatitis C. Recently, co-infection by serologically-silent hepatitis B virus (HBV) has been assumed to be associated with the poor IFN response in patients with chronic hepatitis C. The aim of this study was to investigate the relationship between the co-infection of serologically-silent HBV and type-I IFN receptor gene expression in the liver of patients with chronic hepatitis C. The intrahepatic mRNA levels of IFNAR2, one of the two subunits of the type-I IFN receptor, were quantified and compared with both the prevalence of HBV DNA and the hepatitis C virus (HCV) genotype in 45 patients with chronic hepatitis C, who were negative for hepatitis B surface antigen. Co-infection, as evaluated by a nested polymerase chain reaction, was present in 22 patients (48.9%), with dominance of the HCV genotype 1b (65.2%) over genotype 2a (31.8%). Co-infection was associated with lower IFNAR2 mRNA levels, higher levels of serum HCV RNA, and a poor IFN response, regardless of the HCV genotype. The findings suggest the possibility that co-infection by serologically-silent HBV is one of the factors that can lead to an unfavorable IFN response in chronic hepatitis C by down-regulation of IFN receptor gene expression in the liver.