Acute panmyelosis with myelofibrosis: clinical, immunophenotypic and cytogenetic study of twelve cases

The clinical, cytogenetic, and immunophenotypic features in 12 adult patients with acute panmyelosis with myelofibrosis (APMF; ICD-0-3: 9931/3; C42.1) are reported (median age: 57 years; f/m = 1.4). The white cell count (WBC) was normal in 3 patients; 9 had leucopenia. The median hemoglobin value was 64.5 g/l, and median platelet count 12 x 10(9)/l. Bone marrow biopsy showed a hypercellular marrow in 10/12 patients with a significant infiltration of pathological blasts (range: 30 - 60%). All the cases had marked reticulin fibrosis. Immunophenotyping of bone marrow blast cells showed the expression of early (CD34) and lineage-unspecified antigens (HLA-DR) in 6/7, and 7/7 patients, respectively. "Early" myeloid antigens (CD13, CD33) were seen in 6/7 and 4/6 patients respectively. Monocyte antigen (CD14) was expressed in 3/7 patients. Megakaryocyte antigen (CD61) and erythroid cell antigen (GpA) were each expressed in only 1 patient. Two patients had expression of CD34, HLA-DR and "early" myeloid antigens by their bone marrow blast cells and 1 of these also had a co-expression of the antigens from a differentiated monocytic cell proliferation (lysozyme+, CD68+). Nonspecific chromosomal aberrations were recorded in 8/10 patients. The median survival was 2 months. These findings suggest an immature myeloid phenotype of blast cells in APMF. In 6/9 patients a leukemic cell differentiation into monocytic, megakaryocytic or erythroid lineage was also demonstrated.     

Rates of nucleotide substitution,mutation at a locus,and the "beanbag" gene number in man

We estimated the number of different human genes by relating the patterns of spontaneous mutation at the population and individual level. A geometric distribution model of mutation was used in which the average rates of nucleotide replacement (P) and mutation at a locus (p), obtained by experiment, were used to determine the estimate of the physical size of the coding genome (n) in man. The probabilistic relation used, P = (1 −p) ⁿ⁻¹ p, integrates two different referential time scales of mutation, that of a nucleotide and year and that of a coding gene and generation. The estimates of n, for different values of P and p, are compatible with the experimentally determined genome sizes. The size of the coding portion of the genome appears to be evolutionarily constrained by an interplay between the rate of nucleotide replacement and the pattern of mutation at the level of the individual locus. The evolution of the size of the coding genome may be more dependent on the number of generations than on time. Received: October 26, 2001 / Accepted: January 16, 2002     

Outcome of simultaneous liver-kidney transplantation in highly sensitized,crossmatch-positive patients

BACKGROUND: In simultaneous liver-kidney transplantation (SLKT), the liver has been described to protect the kidney from rejection, and acceptable results are possible despite a pretransplant positive crossmatch. At our center, 21 SLKT have been performed since 1993, 2 of them against a positive crossmatch. OBJECTIVES: In this study we retrospectively analyzed two cases of SLKT after positive pretransplant crossmatch. METHODS: Two highly sensitized women (30 and 52 years) with hepatic cirrhosis VHC on hemodialysis after a first KT failure were assessed. Pretransplant panel reactive antibodies (PRA) by complement dependent cytotoxicity NIH (CDC) were 81% and 99% respectively. Both patients received a SLKT. CM was performed at pretransplant and 24 and 48 hours posttransplant by CDC and by flow cytometry with double labeling with CD3-PE and antihuman IgG-FITC. Patients received ATG, cyclosporine, and prednisone therapy. RESULTS: CM was positive pretransplant by CDC and flow cytometry. At 48 hours, CDC became almost negative (10%-20% mortality) and flow cytometry became negative. One of the patients experienced an episode of acute rejection at 10 days posttransplant that resolved with steroid pulses. Both patients presently have working grafts 26 and 24 months posttransplant (Cr, 1.1 and 1.5 mg/dL; GOT, 34 and 14 IU/L; GTP, 29 and 12 IU/L; GGT, 9 and 66 IU/L). CONCLUSIONS: Our experience suggests that a positive crossmatch is not an absolute contraindication for SLKT. Good graft and patient survival rates are possible even among highly sensitized patients.     

Transient neonatal diabetes mellitus in a child with paternal uniparental disomy of chromosome 6

We report a male infant with transient neonatal diabetes mellitus (TNDM; MIM 601410), macroglossia, hypertelorism, umbilical hernia, inguinoscrotal hernia and onychomycosis. Diabetes mellitus was diagnosed 10 days after birth and resolved after 6.5 months of treatment. Genetic investigation indicated the presence of paternal uniparental disomy of chromosome 6 (UPD 6). The finding of paternal UPD 6 allows prediction of a transient, rather than permanent NDM, and no increased recurrence risk of TNDM in subsequent pregnancies. Therefore, finding of NDM should be a strong indicator for genetic testing.