Specificity and sensitivity of an indirect fluorescent antibody test to detect antibodies against bovine viral diarrhea virus

Since being reported in 1979 and 2006, indirect fluorescent antibody (IFA) tests have not been reported to detect bovine viral diarrhea virus (BVDV) antibodies to our knowledge. Thus, we re-evaluated the efficacy and usefulness of IFA tests for BVDV serology. We tested 4 combinations of 2 antibody conjugates (fluorescein isothiocyanate [FITC]-conjugated rabbit IgG anti-bovine IgG; rabbit IgG F(ab')2 fragment anti-bovine IgG [F(ab')2 FITC-IgG]) and 2 washing solutions (PBS; carbonate-bicarbonate-buffered saline [CBBS]) to evaluate the specificity of an IFA test for BVDV. We compared the sensitivity of the optimal combination with virus neutralization (VN) tests and an ELISA, and compared IFA with VN titers against different genotype (subgenotype) strains. For the F(ab')2 FITC-IgG/CBBS combination, only 1 of the 156 (0.6%) 4-fold diluted cattle sera resulted in a nonspecific reaction; other combinations led to a much higher incidence (22.9-37.2%). For the F(ab')2 FITC-IgG/CBBS combination, IFA detection rates were identical (36 of 59) for BVDV1 and BVDV2 genotypes, and IFA titers against them were strongly correlated (r = 0.99). The antibody-detection rates of the IFA tests were almost identical to those of VN tests and the ELISA (κ: 0.96 and 0.89, respectively). The IFA titers against 4 strains (BVDV1a, BVDV1j, BVDV2a, and an unidentified strain) were similar, 1,024 to ≥4,096, although the VN titers were different. Thus, our IFA tests were specific and sensitive, and more useful than VN tests given that the IFA tests could evaluate the immune status of cattle using a representative strain, regardless of genotype (subgenotype).

Effects of a mixture of medetomidine, midazolam and butorphanol on anesthesia and blood biochemistry and the antagonizing action of atipamezole in hamsters

Syrian golden hamsters (Mesocricetus auratus) are useful laboratory rodents for studying human infectious diseases, metabolic diseases and cancer. In other rodents, such as mice and rats, a mixture of medetomidine, midazolam and butorphanol functions as a useful anesthetic, although it alters some blood biochemical parameters. In this study, we examined the effects of this mixture on anesthesia and blood biochemical parameters, and the action of atipamezole, a medetomidine antagonist, in hamsters. Intramuscular injection of a mixture of medetomidine, midazolam and butorphanol at doses of 0.15, 2.0 and 2.5 mg/kg, respectively, had a short induction time (within 5 min) and produced an anesthetic duration of approximately 100 min in hamsters. We also demonstrated that 0.15 mg/kg of atipamezole, corresponding to the same dose as medetomidine, made hamsters recover quickly from anesthesia. The anesthetic agent markedly altered metabolic parameters, such as plasma glucose and insulin; however, 0.15 mg/kg of atipamezole returned these levels to normal range within approximately 10 min after the injection. The anesthetic also slightly altered mineral levels, such as plasma inorganic phosphorus, calcium and sodium; the latter two were also improved by atipamezole. Our results indicated that the mixture of medetomidine, midazolam, and butorphanol at doses of 0.15, 2.0 and 2.5 mg/kg, respectively, functioned as an effective anesthetic, and atipamezole was useful for antagonizing both anesthesia and biochemical alteration in hamsters.

p16/MTS1/INK4A gene is frequently inactivated by hypermethylation in childhood acute lymphoblastic leukemia with 11q23 translocation

The p16 gene encoding a specific inhibitor of cyclin-dependent kinases 4 and 6 has been reported to be inactivated at a variety of rates in malignant tumors. We studied frequency and mechanism of inactivation of the p16 gene in various types of childhood acute lymphoblastic leukemia (ALL) using 36 leukemic cell lines established from children (B precursor-ALL, 28; B-ALL/Burkitt's lymphoma, 3; and T-ALL, 5). On Southern blot, homozygous deletions or hemizygous deletions with rearrangement were detected in 14 cell lines. The expression of p16 protein was not observed on Western blot in 18 of 22 cell lines with intact p16 gene, but induced in 16 cell lines after treatment with the demethylating agent, indicating the silencing of the p16 gene by hypermethylation. Of note, the p16 gene was inactivated by hypermethylation of the 5' CpG island in nine of nine cell lines with 11q23 translocation, but was restored with the treatment of the demethylating agent. Partial methylation of the p16 gene was also demonstrated in three of eight primary leukemia samples with this translocation, suggesting that the p16 gene inactivation by hypermethylation might play a role in the leukemogenesis and disease progression of ALL with 11q23 translocation.

The KOR-SA3544 antigen predominantly expressed on the surface of Philadelphia chromosome-positive acute lymphoblastic leukemia cells is nonspecific cross-reacting antigen-50/90 (CD66c) and invariably expressed in cytoplasm of human leukemia cells

We previously reported a novel monoclonal antibody KOR-SA3544 which predominantly reacted with a surface antigen (sSA3544) expressed on Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia (ALL). In the present study, we demonstrate that the antibody specifically recognized nonspecific cross-reacting antigen (NCA)-50/90 (CD66c), one of the carcinoembryonic antigen (CEA)-related glycoproteins encoded by a member of the CEA gene family. In addition, we show that the SA3544 antigen (NCA-50/90) was invariably expressed in cytoplasm of all of the human leukemic cell lines examined (sSA3544-positive B-lymphoid two, sSA3544-negative T or B-lymphoid and non-lymphoid 24) regardless of the presence or absence of surface expression of this antigen. Immunoelectromicroscopic examination revealed that the cytoplasmic antigen was mainly present in granules in sSA3544-positive leukemia cells, whereas it was diffusely present in cytosol in sSA3544-negative leukemia cells. Thus, among members of the CEA family, NCA-50/90 was first demonstrated to be expressed not only on the surface of some leukemia cells, but also in cytoplasm of various types of leukemia cells.

Development of acute lymphoblastic leukemia with translocation (4;11) in a young girl with familial pericentric inversion 12

We report a case of a 1-year-old girl with familial pericentric inv(12) who developed acute lymphoblastic leukemia (ALL) with t(4;11) 1 month after recovery from idiopathic hemophagocytic lymphohistiocytosis (HLH). The inv(12)(p13q15) was first found in bone marrow (BM) cells when she was diagnosed as having HLH, and then detected in the BM blasts together with t(4;11)(q21;q23) when she developed ALL. The inv(12) was retained in the BM cells after she achieved complete remission. Cytogenetic analysis on the PHA-stimulated peripheral lymphocytes revealed inv(12) in all of the 30 cells examined. Because the data that ALL with t(4;11) predicts an extremely poor prognosis, she received an allogeneic BM transplantation from an HLA-matched sibling at 10 months from the onset of ALL. She is now at 26 months post transplantation and maintains in a state of complete remission. Familial cytogenetic study demonstrated that 4 of 8 maternal members examined had the inv(12), but they showed no family history of a higher risk of development of hematological and other types of malignancies, suggesting that pericentric inv(12) itself might not be directly involved in the development of ALL in this case.

Clonal hematopoiesis in acquired aplastic anemia revealed by rearrangement of the immunoglobulin heavy chain gene-JH region

We report on a female patient with acquired aplastic anemia whose bone marrow cells showed DNA rearrangement of the immunoglobulin-JH region that disappeared after 1 month with recovery of hematopoiesis through treatment with granulocyte colony-stimulating factor (G-CSF) and immunosuppressive drugs. The patient is now 2 years and 6 months from onset, and her hematopoiesis is almost within normal limits without medication. This finding provides new data supporting clonal hematopoiesis in acquired aplastic anemia but does not imply that the disease is resistant to immunosuppressive therapy.

[Cord blood stem cell transplantation for infantile acute lymphoblastic leukemia after primary cytomegalovirus infection]

We report a 1-year-old boy with infantile lymphoblastic leukemia in first complete remission who received a cord blood stem cell transplantation (CBSCT) from an HLA identical sibling. We collected 120 ml of cord blood when his brother was born, which contained 4.2 x 10(8) mononuclear cells (4.2 x 10(7)/kg) and 3.1 x 10(5) CFU-GM (3.1 x 10(4)/kg). One month prior to transplantation, he showed persistent fever and liver dysfunction, and was finally diagnosed as having primary cytomegalovirus (CMV) infection which was demonstrated by elevation of serum anti-CMV-IgM. The administration of ganciclovir dramatically improved the clinical symptoms and abnormal laboratory findings, and was continued up to 1 month after transplantation to suppress the CMV reactivation. The preconditioning regimen consisted of busulfan (16 mg/kg/4 days) and cyclophosphamide (120 mg/kg/2 days), and cyclosporin A (CyA) alone was used for graft-versus-host disease (GVHD) prophylaxis. Fever suspicious of grade I GVHD developed on day 19, but subsided by increasing the dose of CyA. The WBC and platelet counts reached greater than 1,000/microliter and 50 x 10(3)/microliter on days 12 and 42, respectively. It is now at 13 months since transplantation, and he remains in a disease free state.