Oscillating rows of vortices in superconductors.

Superconductors can be used as dissipation-free electrical conductors as long as vortices are pinned. Vortices in high-temperature superconductors, however, behave anomalously, reflecting the anisotropic layered structure, and can move readily, thus preventing their practical use. Specifically, in a magnetic field tilted toward the layer plane, a special vortex arrangement (chain-lattice state) is formed. Real-time observation of vortices using high-resolution Lorentz microscopy revealed that the images of chain vortices begin to disappear at a much lower temperature, Td, than the superconducting transition temperature, Tc. We attribute this image disappearance to the longitudinal oscillation of vortices along the chains.

Shear stress facilitates tissue-engineered odontogenesis.

Numerous studies have demonstrated the effect of shear stress on osteoblasts, but its effect on odontogenic cells has never been reported. In this study, we focused on the effect of shear stress on facilitating tissue-engineered odontogenesis by dissociated single cells. Cells were harvested from the porcine third molar tooth at the early stage of crown formation, and the isolated heterogeneous cells were seeded on a biodegradable polyglycolic acid fiber mesh. Then, cell-polymer constructs with and without exposure to shear stress were evaluated by in vitro and in vivo studies. In in vitro studies, the expression of both epithelial and mesenchymal odontogenic-related mRNAs was significantly enhanced by shear stress for 2 h. At 12 h after exposure to shear stress, the expression of amelogenin, bone sialoprotein and vimentin protein was significantly enhanced compared with that of control. Moreover, after 7 days, alkaline phosphatase activity exhibited a significant increase without any significant effect on cell proliferation in vitro. In vivo, enamel and dentin tissues formed after 15 weeks of in vivo implantation in constructs exposure to in vitro shear stress for 12 h. Such was not the case in controls. We concluded that shear stress facilitates odontogenic cell differentiation in vitro as well as the process of tooth tissue engineering in vivo.

Morphologic transformation and chromosomal changes induced by chemical carcinogens in skin fibroblasts from patients with familial adenomatosis coli.

Skin fibroblasts from patients with familial adenomatosis coli (AC) and normal individuals were treated once with the carcinogen 4-nitroquinoline 1-oxide or N-methyl-N'-nitro-N-nitrosoguanidine and then passaged sequentially. Morphologically altered cells appeared in the cultures of carcinogen-treated AC fibroblasts at passages 6-8 (days 100-140) after treatment with the carcinogens, but carcinogen-treated normal cells and untreated AC and normal cells did not become altered even after cultivation for 25 passages. The cultures containing morphologically altered cells showed characteristics of transformed cells, such as a high frequency of colony formation in soft agarose, increased growth ability, and chromosomal abnormalities. The results suggest tha AC patients have increased susceptibility to morphologic transformation and chromosomal changes induced by chemical carcinogens.

Genetic changes and histopathological types in colorectal tumors from patients with familial adenomatous polyposis.

Loss of heterozygosity (LOH) and K-ras mutation were analyzed in 111 colorectal polyps and 26 invasive carcinomas from 40 patients with familial adenomatous polyposis of distinct histopathological types. LOH, being less than 2% in moderate adenomas, was detected on chromosome 5q (20%) in severe adenomas, on 5q (26%) and 17p (38%) in intramucosal carcinomas, and on 5q (52%), 17p (56%), 18 (46%), and 22q (33%) in invasive carcinomas. LOH on chromosome 5q occurred most frequently in the region close to the APC gene both in adenomas and carcinomas, and a loss of the normal allele of the APC gene was demonstrated in 3 cases. K-ras mutation markedly increased in the step of development from moderate (11%) to severe (36%) adenomas. These results suggest the following mechanisms for the development of colon tumors in patients with familial adenomatous polyposis: (a) the heterozygous mutant/wild-type condition at the APC gene causes formation of mild or moderate adenoma; (b) the loss of the normal allele in the APC gene leads to a change from moderate to severe adenoma; (c) LOH on chromosome 17p contributes to the conversion of adenoma to intramucosal carcinoma; (d) LOH on other chromosomes, such as 18 and 22q, are involved in the progression of intramucosal carcinoma to invasive carcinoma; and (e) K-ras mutation may also affect the development of moderate to severe adenoma.

Loss of constitutional heterozygosity in colorectal tumors from patients with familial polyposis coli and those with nonpolyposis colorectal carcinoma.

Familial polyposis coli (FPC) is an autosomal dominant tumorigenic disorder, the major gene of which is mapped to chromosome 5q. We searched for a gene loss in colorectal tumors from FPC patients, as related to tumorigenesis by inactivation of tumor suppression genes, using restriction fragment length polymorphism analysis. The findings were compared with those in the case of nonpolyposis colorectal carcinomas (NPCC). We examined specimens from 39 FPC patients, including 21 adenocarcinomas and 49 adenomas, and 23 colorectal carcinomas from 22 NPCC patients. For this, we used 53 polymorphic DNA markers on all autosomes. Frequent loss of heterozygosity in colorectal carcinoma from FPC patients was observed on chromosomes 5 (24%), 14 (20%), 17 (31%), 18 (40%), and 22 (35%) and also on chromosomes 5 (32%), 14 (30%), 17 (27%), 18 (20%), and 22 (19%) in NPCC. Although loss of heterozygosity in adenoma from FPC patients was observed on nine chromosomes, the frequencies were less than 7%. As we fractionated tumors only macroscopically, actual frequencies of loss of heterozygosity are probably somewhat higher. However, these results do suggest that tumor suppression genes for colorectal carcinoma may locate on chromosomes 5, 14, 17, 18, and 22 and that they may play a critical role in carcinogenesis in both FPC and NPCC patients.

Transforming genes from familial adenomatous polyposis patient cells detected by a tumorigenicity assay.

We tried to detect oncogenes associated with familial adenomatous polyposis by a tumorigenicity assay in nude mice. One polyp and two peripheral blood lymphocyte DNAs out of 12 samples from patients induced Alu-positive tumors. Lymphocyte DNAs from one of 5 healthy people also showed tumorigenic activity. The transforming genes of polyps from a patient and lymphocytes from a normal person were found to be the human N-ras gene. Since these N-ras genes were amplified in nude mouse tumors and did not show any alterations in the nucleotide sequences around codons 12 and 61, it is likely that the tumors were induced by the amplified normal N-ras genes. The transforming sequences from two patients' lymphocytes did not hybridize with 12 known oncogene probes, suggesting that these two genes are novel oncogenes or genes for which we have not yet examined the homology. One oncogene derived from a patient's lymphocytes was partially cloned and shown to be located on human chromosome 7. This gene did not hybridize with the met and erbB1 genes, which are potential oncogenes located on chromosome 7. These data indicate that this gene is a new oncogene.

Constitutional translocation t(4;22) (q12;q12.2) associated with neurofibromatosis type 2.

We report on a female patient with bilateral acoustic neurinomas and other tumors in the central nervous system (neurofibromatosis type 2: NF2) and the constitutional translocation, t(4;22) (q12;q12.2). The precise identification of the translocation breakpoint (q12.2) on chromosome 22 implies the refined localization of a gene responsible for NF2, and would provide a clue to its molecular characterization and to the isolation of the gene. Chromosomes of a paraspinal neurinoma from the patient were also analyzed, and the same karyotype as seen in cultured peripheral lymphocytes was found. The patient's father was also a carrier of the translocation, but he had no clinical symptoms of NF2, nor did other relatives. Several explanations are offered for the different expression of the translocation between the patient and her father.

A 14q+ chromosome in a malignant lymphoma in a patient with Down's syndrome.

A 17-year-old Japanese boy with Down's syndrome developed leukemic lymphosarcoma; histology of a lymph node biopsy revealed a malignant lymphoma, of the poorly differentiated lymphocytic (ML-PDL) or possibly lymphoblastic type (ML-LB). The Giemsa-banding technique for chromosome analysis revealed the karyotype of the lymphoma cells to be 47, XY, + 21, 14q+. A chromosome study of PHA-stimulated lymphocytes showed a 21-trisomic pattern, i.e., 47, XY, + 21. The 14q+ marker was a product of a translocation in which the long arm of chromosome No. 8 (probable break at band q11) was translocated to the long arm of a No. 14 at band q32, which is a region usually affected in various types of lymphomas. Two normal No.8 chromosomes were present. Thus, the lymphoma cells were partially trisomic for chromosome No. 8.

Variant Ph1 translocations in CML and their incidence, including two cases with sequential lymphoid and myeloid crises.

A serial cytogenetic study of 110 cases of chronic myelogenous leukemia (CML) has been performed with G- and/or Q-banding techniques with the following results. (1) Seven out of the 110 cases were karyotypically normal. (2) A variant Ph1 translocation was observed in three cases. In one case, the leukemic cells contained two reciprocal translocations, i.e., a t(3;9) (q21;q34) and a t(17;22)(q21;q11); therefore, a Ph1 chromosome was masked by a translocation of the deleted material from the 17q onto the band q11 of the long arm of a chromosome No. 22. In the second case, a variant Ph1 translocation involved chromosomes No. 9, 20, and 22, resulting in a karyotype interpreted as 46,XX,t(9q+;20q+;22q-); in this rearrangement, one of the segments, i.e., 9q31 or 9q33, seemed to be interstitially deleted and inserted into the interstitial region (q11) of a chromosome No. 20 and the 22q11 leads to qter was translocated onto the 9q. This is the first case in which chromosome No. 20 was involved in a variant Ph1 translocation. In the third case, the karyotype of leukemic cells was interpreted as 46,XX,t(5;9;22)(q13;q34;q11). (3) The frequency of Ph1-negative CML and that of Ph1-positive CML with various types of Ph1 translocation from 15 studies reported as series of 25 or more cases, including the present study, have been tabulated. The incidence of a variant Ph1 translocation was 4.1% (42/1027 cases of Ph1-positive CML); of the 42, 13 were of a simple type and 29 of a complex type. (4) In one case of the present study, a masked Ph1 by a translocation of material onto the short arm of the 22q- was observed in the blastic crisis but not in the chronic phase. From the present study and a review of the published cases, it appears that the incidence of such a "masked" Ph1, which cannot be detected by conventional Giemsa staining, is less than 0.6% in CML cases. (5) The first and the second cases with a variant Ph1 translocation mentioned above developed a myeloid blastic crisis after the induction of remission of a lymphoid blastic crisis. For the present, it is unclear whether the occurrence of such blast cells in the two cases and the cytogenetic findings are coincidental. However, the evidence supports the notion of "lymphoid-myeloid" multipotentiality of certain leukemic cells.

Cytogenetic study of chronic lymphocytic leukemia in ten Japanese patients with a case of the same chromosome abnormality both in T and B cells.

Peripheral blood lymphocytes from ten patients with chronic lymphocytic leukemia (CLL) stimulated with phytohemagglutinin (PHA), pokeweed mitogen (PWM), Epstein-Barr virus (EBV), and T-cell growth factor were studied cytogenetically. Eight of ten cases were clinically and immunologically B-cell CLL, and two cases were T-cell CLL. Chromosome analysis revealed that one patient, diagnosed as B-cell CLL, had a clonal abnormality in the leukemic cells. The abnormal karyotype was 46,XY,+3,-15,t(10;19)(q22;p13),t(11;14) (q13;q32),13q+,17q-. The frequencies of the abnormal cell stimulated with PHA, PWM, and EBV were 50%, 13%, and 100%, respectively. Finding the same clonal abnormality after stimulation with three different mitogens suggests that the factor responsible for the development of CLL might affect the stem cell common to T-cell and B-cell lymphocytes. In cells with this abnormal karyotype, chromosome 13q+ seems to have a homogeneous staining region. In the present series of B-cell CLL, no trisomy 12 known to be the specific chromosome abnormality was observed.

Cytogenetic and ultrastructural studies on ten patients with acute promyelocytic leukemia, including one case with a complex translocation.

Chromosomal banding analyses and ultrastructural studies were performed on ten cases of acute promyelocytic leukemia (APL-M3). A reciprocal translocation, t(15q + ;17q-), was found in six of them, and the possible breakpoints of these chromosomes were assigned at bands 15q22 and 17q12. In addition, trisomy 8, trisomy 8 and 21, and an isochromosome of the long arm of the translocated #17, i(17q-), were observed in addition to the 15;17 translocation in three cases, respectively. Furthermore, one patient was found to have a complex translocation in the marrow cells, i.e., 47,XX,+X,t(1p+;5q-;15q+;17q-). Ultrastructural studies demonstrated that the leukemic cells obtained from six of the seven patients with the chromosomal changes involving 17q12 and from two of the three with normal karyotypes contained stellate rough surface endoplasmic reticulum (stellate rER) complexes and/or inclusion bodies in part of the dilated rER.

Chronic myelogenous leukemia with a complex Ph1 translocation in an XYY male.

We encountered a 38-year-old Japanese male patient with chronic myelogenous leukemia (CML), whose bone marrow and peripheral blood cells during the chronic and blastic phases contained a complex Ph1 translocation and an extra Y chromosome [i.e., 47,XYY,t(9;22;13)(q34;q11;q14)]. A karyotypic analysis of PHA-stimulated lymphocytes showed the constitutional karyotype to be 47,XYY. Thus, it was considered that CML with a complex Ph1 translocation developed in an XYY male; such a case has not been reported, so far. A B-lymphocyte cell line with the complex Ph1 translocation was established by the procedure of Epstein-Barr virus transformation. The presence of the complex Ph1 translocation in the B-lymphocyte cell line suggests that some of the B lymphocytes in this patient originated from the CML clone.

Characterization of extramedullary tumors in a case of Ph-positive chronic myelogenous leukemia: possible involvement of immature T lymphocytes.

A 42-year-old male with chronic myelogenous leukemia (CML) developed acute transformation associated with subcutaneous tumors. Histopathologic examinations of the tumors were done on two occasions; the first study revealed reticulum cell sarcoma-like features, and the second suggested a blastoma. Chromosomal analysis showed that the cells of the tumors originated from the CML clone. The cells had a negative reaction for myeloperoxidase by electron microscopy. Furthermore, biochemical and surface marker studies revealed that the tumor cells contained a significant terminal transferase activity. However, they did not express E- or EAC-rosette receptors, Ia-like antigens, or common ALL antigens.

A variant Burkitt-type translocation (2p-;8q+) in a patient with diffuse large cell lymphoma.

A case of diffuse large cell lymphoma with t(2p-;8q+) is reported. Immunologically the lymphoma cells were shown to be of B-cell origin and positive for surface gamma and kappa chains, B4, CALLA, and Ia1 markers. Karyotypically three major clones were detected: 47,XX, + 12,t(2;8)(p11-13;q24) (52%); 47,XX, + 12 (26%); and 46,XX,t(2;8)(p11-13;q24) (15%). A t(2p-;8q +) has been exclusively reported in cases of Burkitt's lymphoma or Burkitt-type acute lymphocytic leukemia. The present case is the first one with t(2p-;8q +) observed in non-Burkitt-type lymphoid malignancy of the B-cell lineage. The t(2p-;8q +) may play a primary role in the early stage of transformation of B cells, and trisomy 12 may provide them secondarily with an advantage for tumor progression. The phenotypic pictures provided by 8q24 rearrangements seem to be heterogeneous, as previously suggested.

Chromosome rearrangements at 12q13 in two cases of chondrosarcomas.

We analyzed the karyotypes of two moderately differentiated (grade 2) chondrosarcomas. Case 1 had a reciprocal translocation between chromosomes 6 and 12, t(6;12)(q25;q13) in most of the cells analyzed, as well as trisomies of chromosomes 7, 8, 11, 17, 19, and 21 and tetrasomy of chromosome 19. A reciprocal translocation involving chromosomes 12 and 19, t(12;19)(q13;q13), was noted as a highly clonal abnormality in the other case. Some cells had t(12;19) as the sole chromosome abnormality. Thus, chromosome rearrangements involving the long arm of chromosome 12 at the same region (q13) were commonly identified in the two tumors. These findings suggest that the rearrangements at 12q13 are nonrandom acquired changes that characterize a subgroup of chondrosarcomas.

Aspartate aminotransferase-linked immunoglobulin complexes in serum of a patient with primary biliary cirrhosis.

A 51-year-old woman who had been treated for primary biliary cirrhosis (PBC) was admitted to our hospital for evaluation of unexplained, isolated, persistently increased aspartate aminotransferase (AST) activity. Results of laboratory tests on admission showed: AST 171 KU, alanine aminotransferase 28 KU, and anti-mitochondrial titer 1/1280. Results of hepatitis B surface antigen (HBs Ag) and hepatitis C virus antibody (HCV Ab; C100-3) assays were negative. Histology of a liver biopsy specimen was compatible with a diagnosis of PBC (stage III of Scheuer's classification). The molecular size of serum AST was estimated to be more than 500,000 by high-performance size-exclusion liquid chromatography. Electrophoretic analysis showed an abnormal band of AST between supernatant AST (sAST) and mitochondrial AST (mAST), which band was characteristic of AST-immunoglobulin complexes (AST-Ig). Ouchterlony double-diffusion and immunoprecipitation tests identified the immunoglobulin component as IgM. The presence of AST-Ig appeared to be responsible for the elevated serum AST.

The biological activity of hydrogen peroxide. I. Induction of chromosome-type aberrations susceptible to inhibition by scavengers of hydroxyl radicals in human embryonic fibroblasts.

The cytogenetic effect of hydrogen peroxide (H2O2) was investigated in human embryonic fibroblasts. Chromosome-type aberrations were found together with chromatid-type aberrations in metaphase cells harvested 24 h after a single 10-min treatment with 10(-5)-10(-3) M H2O2 in 0.9% NaCl solution. The chromosome-type aberrations were observed to be predominantly dicentrics and deletions. Both types of aberration showed a dose-response relationship to the dose of H2O2 over the range of 10(-5)-1.5 X 10(-4) M H2O2. The intercellular distribution of dicentrics showed a Poisson distribution. Centric and acentric rings and abnormal monocentrics were a minor fraction of the chromosome-type aberrations. The chromatid-type aberrations observed, such as breaks, exchanges and gaps, showed no dose-response relationship. The frequency of isochromatid breaks was higher than that of chromatid breaks and approximately 70% of the isochromatid breaks were found in the centromeric or pericentromeric region. The intercellular distribution of chromatid exchanges showed an over-dispersed distribution. The generation of aberrations by H2O2 was effectively suppressed by catalase and several scavengers of hydroxyl radicals (.OH) such as ethanol, dimethyl sulfoxide (DMSO) and mannitol. This result suggest that .OH plays an essential role in the generation of the chromosome aberrations by H2O2.

Clinical features in a girl with Duchenne muscular dystrophy with an X-autosome translocation; (X;4)(p21;q26).

A female with Duchenne muscular dystrophy (DMD) and an X/4 translocation is reported. Her clinical signs, laboratory data and muscle pathology are compatible with those of typical DMD. She also has a ASD, type II, with some kind of cardiomyopathy. Detailed cytogenetic analyses by means of high resolution banding and R-banding techniques showed that the exchange point was located in band p21 of the X chromosome, suggesting the localization of the DMD gene within it. The clinical course of DMD in a female with an X/autosome translocation is variable, as in the case of heterozygous females, compared with that in male patients. The mild phenotype in female cases with an X/autosome translocation could be explained by the fact that in some cultured cells the normal X chromosomes replicate early and therefore may be active.