The normally expressed κ immunoglobulin light chain gene repertoire and somatic mutations studied by single-sided specific polymerase chain reaction (PCR); frequent occurrence of features often assigned to autoimmunity

The expressed human κ light chain gene repertoire utilized by healthy individuals was studied by two different single-sided specific PCR techniques to avoid bias for certain V genes. A total of 103 rearranged κ sequences from peripheral blood mononuclear cells from healthy individuals were cloned from cDNA and assigned to the Vκ and Jκ germ-line genes with the closest overall homology. The use of cDNA rather than genomic DNA focused the analysis on activated B cells rich in mRNA. Accordingly, the sequences represented the applied repertoire and almost all were somatically mutated. V genes from the Jκ-proximal duplication unit of the κ locus were almost exclusively used. A total of 65% of the sequences could be assigned to four or five genes: A27 (humkv325), L6 (Vg), L2 (humkv328), and A3 and/or A19. N additions and P nucleotides were quite common and found in 32% and 21% of the sequences, respectively. Extended CDR3s more than nine residues in length were found in 18% of the sequences, and in 71% of cases this was due to insertion of an extra proline residue. This proline was usually explained from the germ-line sequences involved. These results are in good agreement with those of previous repertoire studies using potentially V-gene-biased techniques. Thus, it is clear that restricted V-gene usage, common N and P additions, and extended CDR3 regions are normal features and not, as has been claimed, characteristics of pathological autoantibodies.     

Hematopoietic turnover index in reactive and neoplastic bone marrow lesions: quantification by apoptosis and PCNA labeling

 In order to determine the dynamics of hematopoietic cell turnover, proliferative activity and incidence of apoptosis (programmed cell death) were evaluated in bone marrow trephine biopsies. Selection of patients (20 in each group) included in addition to a control group, idiopathic thrombocytopenia (ITP), reactive thrombocytosis (TH), secondary polycythemia-smokers' polyglobuly (PG), primary (essential-hemorrhagic) thrombocythemia (PTH), polycythemia vera (PV), and finally acute myeloid leukemia (AML). Apoptosis was demonstrated by the in situ end-labeling technique (ISEL) and proliferative activity by applying the monoclonal antibody PC10 raised against proliferating cell nuclear antigen (PCNA). To assess dynamic features of hematopoiesis, an index was calculated consisting of the ratio between PCNA-positive nuclei and the apoptotic cell fraction. This factor was termed the hematopoietic turnover index (HTI). Morphometric analysis revealed that the HTI was significantly increased in AML and PV. According to cell culture studies both disorders are characterized by either a prevalent proliferation of the myeloid or erythroid cell mass. On the other hand, PG, PTH, and TH showed no relevant enhancement of this index in comparison to the control specimen. In vitro experiment results are in keeping with the finding that PG and PTH are not associated with a significant expansion of the erythroid lineage (CFU-E). Similar to ITP and TH, in PTH megakaryocyte proliferation (CFU-MEG) is the predominant feature of cell turnover. Differences between PTH and TH are in line with the reduced in vitro formation of CFU-MEG in the latter disorder. In conclusion, our in situ study on turnover rates of the bone marrow in various neoplastic and reactive lesions extends previous experimental data on hematopoietic cell kinetics. Received: 10 March 1997 / Accepted: 18 May 1997     

Emergence and scattering of multiple neurofibromatosis (NF1)-related sequences during hominoid evolution suggest a process of pericentromeric interchromosomal transposition

Type 1 neurofibromatosis (NF1) gene encodes for a member of the GTPase activating protein family and is considered to be a tumor suppressor gene. Its very high rate of de novo mutation in humans led us to study a specific feature of this gene: the presence of numerous NF1-related sequences. According to our results, the human genome contains at least 11 NF1-related sequences, nine of which are scattered near centromeric sequences of seven different chromosomes. These NF1-related sequences, whose extent is quite varied according to loci, are unprocessed copies of the NF1 gene, and bear numerous mutations. A phylogenetic analysis of the six largest sequences indicates that they are all derived from a common ancestor, which would have appeared 22-33 million years ago, and was subsequently duplicated several times during hominoid evolution. The most recent duplication and interchromosomal transposition occurred in the last million years suggesting that the process could still be ongoing. Intriguing similarities between the evolution of alpha- satellite DNA and NF1-related sequences suggest the involvement of a common genetic mechanism for the generation and pericentric spreading of these NF1 partial copies.      

Contribution of ESR dosimetry for irradiation of geological and archaeological samples with a Co panoramic source

A very precise dosimetry of a field of artificial irradiation is essential to estimate an accurate ESR Equivalent Dose (ED) in archaeology and geology. Archaeological powder samples and one sample of DL-alanine powder as control were prepared by IPH. Some alanine dosimeters of LMRI, constituted of L-alanine pellets, were joined to the IPH samples and together, irradiated in boxes using panoramic ⁶⁰Co source under different experimental conditions. The LMRI had in charge the control of the process of irradiation and the measurement of each absorbed dose and dose rate delivered to the different series of boxes. This study consists in the evaluation of the distribution of dose on the samples. The ESR measurements made by the two laboratories were analysed and then compared. These experiments showed a significant gradient in the absorbed dose delivered to each LMRI dosimeter. The dispersion in each box was easily observable. However, a good agreement between the dosimeters and the alanine powder was observed in a same box.     

Self-directed learning in anatomy: incorporation of case-based studies into a conventional medical curriculum

This paper reports an attempt to develop self-directed learning skills in second-year medical students by introducing case-based projects into the gross anatomy course at a long-established medical school. The programme and students' responses to a questionnaire completed at the end of the year are presented. Information on the various resources used by students to find information is given. The performance of students in the case-based components of the course has been evaluated and also in the more traditional end-of-year written examination. The data confirm that students have recognized that the projects were about obtaining a deeper understanding of the anatomy, and the programme appears to have promoted the use and study of library texts.     

Treatment of equino-excavato-varus deformity of the feet in adults using a hinge-distraction apparatus

The treatment of severe aggravated forms of equino-excavato-varus deformation of the feet of various etiology is rather difficult because the resections performed to eliminate the deformation require the removal of large quantities of the bone tissue and are traumatic, and when accompanied by neurotrophic disturbances they are usually contraindicated. At the Central Institute of Traumatology and Orthopaedics 65 patients with acutely pronounced feet deformations have been treated with Volkov-Organesian-Povarov distraction apparatuses. In 34 patients the deformation was accompanied by various neurotrophic disturbances. The results were good in 61 feet, satisfactory in 18 feet and bad in 4 feet. The experiment has demonstrated the efficacy of apparatus treatment, especially in the cases of aggravated forms of feet deformations, where this method often is the only one available.     

Specific features of osteosynthesis using a pivotal compression-distraction apparatus

The article is devoted to the analysis of 5-year-long application experience of the rod-based apparatus with external fixation. The apparatus have been developed at the institute named after prof. M. I. Sitenko. Certain advantages and indications for rod-fixation in traumatology have been substantiated. In urgent traumatology the apparatus made the best showing in treatment of the open fractures. Possibility of these apparatus application as the treatment-and-transportation immobilization facilities in case of mass entrance of victims has been demonstrated. Rod-based apparatus are widely used for fixation in case of correcting osteotomies, limb stretching (especially of the femoral segment) in children as well as for fixation of the instable spine damages. Complications in case of rod application manifest themselves as suppuration of the soft tissues and osteomyelitis. But their number is lower as compared with the wire apparatus application.