More HLA haploidentity in pairs of sibs with the same transcortin levels

In 50 sibships, each comprising at least 2 male sibs, the oldest sib was paired with each of his brothers. All sibs were HLA- haplotyped and their serum transcortin level was determined. The HLA haploidentical pairs were compared with the sibpairs having no HLA haplotype in common. The odds for the haploidentical pairs of having a small difference (less than 0.07 mg per g total serum protein) in serum transcortin was nearly 4 times (3.94; P less than 0.025) greater than for the pairs of brothers having no HLA haplotype in common. This abnormal distribution in HLA haplotypes confirms our previous findings on the relation of certain HLA haplotypes with either high or low basal serum transcortin levels.     

Prevalence of HTLV-I and HTLV-II infection in Gabon, Africa: comparison of the serological and PCR results

A cluster sampling survey was performed in 1989 in Libreville, Gabon, to determine HTLV-I and HTLV-II prevalence and to compare the efficacy of polymerase chain reaction (PCR) and serology in detecting HTLV-I and HTLV-II infections. A total of 322 sera from adults were tested by ELISA and by Western blot (WB). The WB patterns were interpreted according to WHO criteria and those of the manufacturer. PCR analysis using primer pairs in the gag and pol region, with a specific probe for HTLV-I and HTLV-II, was performed on the lymphocytes of the 322 adults. In addition, 134/322 samples were re-tested with tax primers, in a second laboratory. Using WHO criteria, 8/322 (2.5%) samples were positive on WB and 25 were indeterminate; with the criteria of the kit, 26/322 (8.1%) were positive and 7 were indeterminate by WB. By PCR, 13 (4%) samples were positive, including 12 for HTLV-I (3.7%) and one for HTLV-II (0.3%). All 8 seropositive samples (by the WHO criteria) were positive by PCR, as were 4 out of 25 indeterminate samples. Only one out of 289 seronegative samples was positive by PCR. In contrast, only 12/26 positive samples by the kit criteria were confirmed by PCR. These results confirm the relatively high HTLV-I/II seroprevalence observed in Gabon. HTLV-I infection is preponderant, but HTLV-II is also present. The WHO criteria for WB give a better fit with PCR results than the kit criteria for WB. In the absence of a specific confirmatory test and based on the uncommon "seronegative" HTLV-I/II infection, the indication for PCR appears limited to the positive WB samples (to differentiate HTLV-I and II infection) and to the indeterminate WB samples.     

Anti-idiotypic and anti-anti-idiotypic antibodies as highly specific tools in epitope and active site studies on human interferon-gamma.

Immunization of rabbits with F(ab')2 fragments of different monoclonal antibodies directed against human interferon-gamma yielded antisera with anti-idiotypic characteristics. Isolation of the anti-idiotypic fraction, resulting in a highly specific antiserum, allowed us to prove that out of six competing monoclonal antibodies directed against human interferon-gamma, only two really recognize the same epitope. The other monoclonal antibodies compete on the basis of steric hindrance, which is not surprising, because of the large difference in Mr between interferon-gamma and an immunoglobulin. The anti-idiotypes provided us also with a tool to study isolated epitopes on the human interferon-gamma molecule, a task which was previously not practicable. Exploration of the biological properties of these anti-idiotypes allows us to determine whether the investigated epitopes are involved in receptor binding. The production of an anti-anti-idiotypic antiserum not only proved that we generated real internal images, but also that these images conserved all of their properties, although with a decreased affinity in comparison with the original monoclonal antibody. As the former is a polyclonal antiserum, directed against a single epitope of the human interferon-gamma molecule, competition experiments yielded additional information on the relative position of three epitopes recognized by inhibiting monoclonal antibodies. These antisera will possibly open new ways for the affinity purification of interferon-gamma and perhaps for the treatment of autoimmune diseases.     

Reciprocal translocation t(6;9)(p21;q33): a new characteristic chromosome anomaly in myeloid leukemias

Three patients with myeloproliferative disorders, two acute myeloid leukemias and one chronic myelocytic leukemia, were found to present a t(6;9)(p21;q33) as the sole anomaly in the leukemic cells. It is likely that this translocation is to be added to the steadily growing list of characteristic chromosome changes in human malignancy.     

High incidence of chromosome abnormalities in IgG3 myeloma

Chromosomes were studied in 33 untreated myeloma patients, and results were correlated with the class of Ig secreted by the myeloma cells. A high incidence of clonal karyotypic anomalies seemed to be present in IgG3 myeloma patients, in whom the disease was advanced at diagnosis and rapidly progressing. Among the chromosome anomalies, the t(11;14)(q14;q32) was particularly prominent, and this chromosome anomaly, in analogy with the Ph1 chromosome, may characterize a family of lymphoproliferative disorders.     

Chromosome analysis in two unusual malignant blood disorders presumably induced by benzene.

Two patients with presumably benzene-induced malignant blood disorders with preleukemic phases were cytogenetically monitored through the courses of their diseases. Patient 1, in addition to a familial chromosome translocation [t(3;16)], developed karyotypic abnormalities in 100% of the marrow cells, including two translocation: t(9;16)] and t(4;15). Monosomy of chromosome 7 characterized the cells of patient 2. Cytogenetic monitoring of the patients at various phases of their diseases served as an important indicator of the transformation or progression of the preleukemia into frank leukemia and of the unusual behavior of such leukemic cells.     

Transformation of polycythemia vera to myelofibrosis and late appearance of a 5q— Chromosome anomaly

A characteristic 5 q− interstitial deletion was found to occur late during the course of the disease in three patients with polycythemia vera, and accompanied the transformation to myelofibrosis and the appearance of a preleukemic disorder.     

Simultaneous occurrence of myelodysplastic syndrome and monoclonal B lymphocytes with a different clonal origin

Bone marrow and peripheral blood from a myelodysplastic syndrome patient with trisomy 13 and monoclonal B lymphocytes (without evidence of systemic lymphoma) were investigated for clonal lymphoid lineage involvement using interphase fluorescence in situ hybridization (FISH) and X-chromosome inactivation assay (HUMARA) on CD19+ and CD34+ sorted cells. Trisomy 13 was detected in 55% of CD34+ cells and in 5.5% of CD19+ cells, the latter being comparable to the negative control specimen. X-chromosome inactivation showed both CD34+ and CD19+ cells to be monoclonal, though their inactivated X-chromosome was different. The results strongly suggested that both populations of CD34+ and CD19+ cells have originated from a different progenitor stem cell.     

BS-SEM evaluation of the tissular interactions between cortical bone and calcium-phosphate covered titanium implants

The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes.