Palaeoanthropology: Did our ancestors knuckle-walk?
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Animals↗
Biomedical subjects
M Dainton
Publications and source records attributed to M Dainton.
Did knuckle walking evolve twice?
Although African great apes share a similar quadrupedal locomotor behaviour, there are marked differences in hand morphology and size between the species. Hence, whilst all three species (two genera) of African ape frequently knuckle walk as adults, debate remains as to whether this behaviour is derived from a common ancestor or whether it evolved in parallel in chimpanzees and gorillas. This exploratory morphometric study of the sub-adult and adult wrist of these two genera aims to contribute to this debate. A total of twenty-seven dimensions of the lunate, triquetral, hamate and capitate of sub-adult and adult Pan troglodytes and Gorilla gorilla were analysed in order to determine whether carpal dimensions are generally ontogenetically scaled, and whether differences in growth trajectories, or length of growth, and adult morphologies can be explained by behavioural differences between the two species. Only 56% of all dimensions studied were ontogenetically scaled in sub-adults and some of these dimensions exhibit differing adult proportions between the two species. In general, the dimensions analysed fell into two categories: Pan and Gorilla either follow the same growth trajectories (Pattern A) or the Pan reduced major axis (RMA) regressions were significantly transposed above those of Gorilla (Pattern B). Additionally, it was found that Gorilla carpals appear to cease growing relatively earlier than those of Pan. While a small number of differences, notably those of the lunate, can be accounted for by differences in behaviour between the species, the majority of differences indicate heterochronic modifications of development during evolution, which correspond to kinematic differences in knuckle walking between the African great apes. In light of morphological, behavioural and ecological data currently available it is parsimonious to suggest that knuckle walking has evolved in parallel in the two lineages.
Animals↗
Fluorescence in situ hybridization analysis of t(3; 12)(q26; p13): a recurring chromosomal abnormality involving the TEL gene (ETV6) in myelodysplastic syndromes.
We have identified a new recurrent reciprocal translocation between chromosome 3 and 12 with breakpoints at bands 3q26 and 12p13, t(3;12)(q26;p13) in the malignant cells from five patients with acute transformation of myelodysplastic syndrome or blast crisis of chronic myelogenous leukemia. t(3;12)(q26;p13) appears as a rare but nonrandom event present in various myeloid leukemia subtypes, which is frequently associated with dysplasia of megakaryocytes, multilineage involvement, short duration of any blastic phase, and a very poor prognosis. Here, we report the molecular cytogenetic analysis of the t(3;12). Fluorescence in situ hybridization results indicate that the 3q26 breakpoints are quite heterogeneous and occur 5' of MDS1, 3' of EVI1, or between MDS1 and EVI1. Our results are very similar to those observed in other 3q26 rearrangements in which breakpoints were shown to occur over considerable distances 5' and 3' of EVI1. Fluorescence in situ hybridization investigations proved that, in three myelodysplastic syndrome cases with t(3;12)(q26;p13), the 12p 13 breakpoint occurred within the TEL gene.
Adult↗
Peripheral blood stem cells used to augment autologous bone marrow transplantation.
Peripheral blood stem cells (PBSC) were used to augment autologous bone marrow transplantation (ABMT), aiming to hasten engraftment after high dose treatment in a group of heavily pretreated patients. PBSC were obtained by leukapheresis during the rebound after standard chemotherapy. In 11 patients aged 7-17 years, high dose chemotherapy consisted of busulphan 16 mg/kg orally with melphalan 160 mg/m2 intravenously for seven patients, and melphalan 200 mg/m2 intravenously alone for four. The median number of granulocyte-macrophage colony forming units in the reinfused PBSC was 3.42 x 10(4)/kg (3.03-18.01) and bone marrow 12.4 x 10(4)/kg (4.16-28.6). Neutrophil recovery to > or = 0.5 x 10(9)/l and platelet transfusion independence occurred at a median of 14 days (11-18) and 22 days (9-84) respectively. In five patients the early engraftment was transient with neutrophils again dropping below 0.5 x 10(9)/l then slowly recovering. There was one toxic death due to sepsis. PBSC harvesting in these children was undertaken without interrupting routine chemotherapy and without the use of bone marrow growth factors. In some patients PBSC failed to influence engraftment and the use of combined chemotherapy and growth factor priming for PBSC collection may give improved results.
Acute Disease↗
Transplantation of autologous peripheral blood stem cells mobilized using GM-CSF for acute leukemia with myelofibrosis.
A patient with acute mixed lineage leukemia had marked marrow fibrosis at presentation. The fibrosis persisted despite achievement of complete remission. Because the marrow was inaspirable, granulocyte-monocyte colony-stimulating factor (GM-CSF) was used to mobilize stem cells into the peripheral blood which were used for autologous transplantation. Myeloid engraftment was rapid. The extent of the fibrosis decreased after transplantation. GM-CSF-mobilized peripheral blood stem cells may be used for autologous transplantation in patients with fibrotic marrows who are not candidates for allografting.
Acute Disease↗