Some considerations on the geographical distribution of rotifers

In the course of investigations on the systematics and zoogeography of rotifers, the author found that 48% of all taxa treated showed a limited distribution (most were periphytic or benthic periphytic species from shallow waters). The following species were limited to the Palaearctic Region: Marine: Synchaeta triophtalma Lauterborn, S. vorax Rousselet, and S. curvata Lie-Pettersen. Brackish water: Colurella dicentra (Gosse), C. halophila Wulfert, and C. unicauda Eriksen. Among Holarctic species, Notholca psammarina Buchholz & Rühmann and the two semi-species N.(striata) bipalium (O. F. Müller) and N(striata) striata (O. F. Müller) are discussed. A series of warm-stenothermic species were found to be pantropical: Lecane leontina Turner, L. monostyla (Daday), L. harringi (Ahlstrom), Lepadella latusinus (Hilgendorf), Trichocerca chattoni (de Beauchamp), and Platyias leloupi Gillard, while Lecane plesia Myers and L. punctata (Murray) seemed to be confined to the Neotropical Region. The data collected also suggest that:

1. i) Keratella wirketissi Kutikova, K. kamtchatica Kutikova, K. cruciformis (Thompson), and K. eichwaldi (Levander) might be good species.
2. ii) Brachionus forficula Wierzejski, an Old World species, is a geographical vicariant of both B. havanaensis Rousselet and B. trahea Murray from the New World.
3. iii) Cases of ecological vicariance are found in Testidinella elliptica (Ehrb.) and T. clypeata (O. F. Müller) from fresh and brackish water respectively; Keratella cruciformis (Thompson) and K. eichwaldi (Levander) from the sea and brackish water respectively; Keratella quadrata (O. F. Müller), K. valga (Ehrb.), and K. tropica (Apstein), dominant in arctic to cold-moderate, in warm-temperate, and in subtropical-tropical climates respectively.

Some rotifer species are presently in expansion: the cases of K. tropica and of Brachionus falcatus Zacharias in Europe are analysed. A related case is that of man-made faunas: the presence of Brachionus havanaensis in Sangchrist Lake, Ill., USA, and the Rotifer fauna of the River Loire (France) are discussed.     

Characterisation and developmental potential of ovine bone marrow derived mesenchymal stem cells

Since discovery, significant interest has been generated in the potential application of mesenchymal stem cells or multipotential stromal cells (MSC) for tissue regeneration and repair, due to their proliferative and multipotential capabilities. Although the sheep is often used as a large animal model for translating potential therapies for musculoskeletal injury and repair, the characteristics of MSC from ovine bone marrow have been inadequately described. Histological and gene expression studies have previously shown that ovine MSC share similar properties with human and rodents MSC, including their capacity for clonogenic growth and multiple stromal lineage differentiation. In the present study, ovine bone marrow derived MSCs positively express cell surface markers associated with MSC such as CD29, CD44 and CD166, and lacked expression of CD14, CD31 and CD45. Under serum‐deprived conditions, proliferation of MSC occurred in response to EGF, PDGF, FGF‐2, IGF‐1 and most significantly TGF‐α. While subcutaneous transplantation of ovine MSC in association with a ceramic HA/TCP carrier into immunocomprimised mice resulted in ectopic osteogenesis, adipogenesis and haematopoietic‐support activity, transplantation of these cells within a gelatin sponge displayed partial chondrogenesis. The comprehensive characterisation of ovine MSC described herein provides important information for future translational studies involving ovine MSC. J. Cell. Physiol. 219: 324–333, 2009. © 2008 Wiley‐Liss, Inc.     

The morphology of the European miocene hominid frontal bone: functional,developmental and phylogenetic considerations

This paper re-interprets the morphology of fossil and extant hominid frontal bones in light of development, functional and phylogenetic considerations. It is argued that the suggested inclusion of Hispanopithecus and Ankarapithecus as members of the Ponginae (which has partly been based on frontal bone morphology) remains problematic as their similarity with other members of the Ponginae is likely the result of distinct developmental processes resulting in Hispanopithecus and Ankarapithecus sharing an anatomical analogy with this subfamily. Whether this can be used to argue against their inclusion within the Ponginae remains debatable, as we still do not appreciate degrees of developmental variability within and between taxa, nor their phylogenetic significance in closely related taxa. The frontal bone morphology as observed in Hispanopithecus and Ankarapithecus, however, suggests that they share a sister-group relationship. In terms of the Homininae, Graecopithecus is supported as a likely member of this subfamily, while Dryopithecus is considered as a primitive member of the Hominidae.     

Mock retroviral infection alters the developmental potential of murine bone marrow stem cells.

Retroviral vectors were used to introduce an activated ras gene into murine pluripotent hemopoietic stem cells. We attempted to reconstitute the hemopoietic system of lethally irradiated mice with isolated spleen colonies obtained in vivo after injection of infected bone marrow cells. Spleen colonies derived from infected bone marrow were inefficient in promoting long-term survival of irradiated hosts. This loss of reconstitutive capacity of spleen colonies was not due to the retroviral infection per se but to the in vitro culture of spleen colony precursors. Incubation for 24 h in the presence of fetal calf serum and interleukin-3 without virus-producing cells was sufficient to abolish completely the reconstitutive capacity of spleen colonies while maintaining both self-renewal and pluripotential capacities of spleen colony precursors. These results show that the in vitro manipulation of stem cells that is included in current protocols for retroviral infection can modify the developmental potential of these cells. This finding clearly indicates that the use of retroviral vectors can introduce a bias in the analysis of hemopoiesis.     

Some physiological and biochemical considerations of larval development in the American lobster,Homarus Americanus Milne Edwards

The weight-specific respiration rates of fed and starved lobsters and the ammonia excretion rates of fed lobsters increased with each larval stage (I through IV) and decreased with the first postlarval stage (V). The rate of change in metabolic rates was greater than the rate of change of body size of the larval stages, indicating an increased energy demand of the later larval stages. There was no significant difference in the O: N ratio for the first three larval stages but a reduction was observed in stage IV and V lobsters, reflecting an increased dependence on protein catabolism for energy.Protein was the principal biochemical constituent of all lobster stages. Significant decreases in lipid content and increases in ash and chitin content of the last larval (IV) and first postlarval (V) stages were detected.     

The assessment of micronucleated polychromatic erythrocytes in rat bone marrow. Technical and statistical considerations

Traditionally, the mouse is the species of choice for the rodent bone marrow micronucleus assay (MN). However, the rat is used for most other toxicological studies. The suitability of the rat as a test species for the MN was therefore investigated. In this paper, the methodological aspects of the assay have been considered. The distribution and incidence of micronucleated polychromatic erythrocytes (MPEs) on bone marrow slides prepared by two techniques, the conventional smear and the paint-brush technique, were assessed in control and cyclophosphamide-dosed male and females rats. MPEs were shown to be homogeneously distributed when assessed over a large number of PEs on slides prepared by both techniques, but when viewed over a few hundred PEs (less than 500 PEs), the incidence of MPEs on the same slides was seen to vary considerably (0-10 MPEs/500 PEs). Variability was within acceptable limits when at least 1000 PEs/animal were analysed. The spontaneous incidence of MPEs in the AP rat is low (0-2 MPEs/1000 PEs). Cyclophosphamide increased the incidence markedly and there was a wide inter-animal variability in the response (10-40 MPEs/1000 PEs). The paint-brush technique is considered technically simpler and recommended over the smear technique. This study shows that MPEs can be accurately scored in the bone-marrow of the rate provided due consideration is given to staining and sample size of PEs analysed per animal.     

Stress, chemocommunication, and the physiological hypothesis of mutation

The review considers stress as a physiological state of the organism, affecting the cellular, genomic, and population levels. Literature data and cytogenetic studies by the author support basic statements of the physiological hypothesis of mutation, which was advanced as early as in the 1940s. Studies of pheromonal effects in germline and somatic cells of the house mouse demonstrated the role of olfactory stressors in generating genetic variation in microevolutionary changes.     

Stress,chemocommunication, and the physiological hypothesis of mutation

The review considers stress as a physiological state of the organism, affecting the cellular, genomic, and population levels. Literature data and cytogenetic studies by the author support basic statements of the physiological hypothesis of mutation, which was advanced as early as in the 1940s. Studies of pheromonal effects in germline and somatic cells of the house mouse demonstrated the role of olfactory stressors in generating genetic variation in microevolutionary changes.     

Activity and distribution of lysosomal enzymes during collagenous matrix-induced cartilage,bone, and bone marrow development

The appearance of the lysosomal enzymes acid phosphatase, arylsulfatase, and β-glucuronidase was studied during endochondral bone and bone marrow formation induced by implantation of demineralized bone matrix. The activities of acid phosphatase and β-glucuronidase gradually increased from the stage of mesenchymal cell proliferation on Day 3 onward to reach a peak on Day 13, during maximal bone remodeling. However, arysulfatase activity exhibited a sharp increase on Day 9, associated with the onset of cartilage hypertrophy and chondrolysis. The peak of arylsulfatase activity was also attained on Day 13. The activities of all three enzymes declined on Day 15 but acid phosphatase again exhibited an increase during hematopoietic bone marrow differentiation on Days 19–21. Histochemical and ultrastructural studies revealed intense lysosomal enzyme activity in macrophage-like cells on Day 7 and thereafter. During chondrolysis and bone remodeling, these cells were present in a perivascular location. Osteoclasts also exhibited strong reactivity for the lysosomal enzymes. Due to its characteristic temporal appearance during development of endochondral bone, arysulfatase may be used as a marker enzyme for chondrolysis and bone resorption.     

Matrix metalloproteinases in bone marrow: roles of gelatinases in physiological hematopoiesis and hematopoietic malignancies

Turnover balance of extracellular matrix (ECM) is a prerequisite for the structural and functional homeostasis of bone marrow (BM) microenvironment. The role of ECM in physiologic hematopoiesis and its pathologic change in hematopoietic malignancies are very important and under extensive investigation. Accumulating evidence suggests that matrix metalloproteinases (MMPs), a family of zinc-dependent proteinases, take an active part in the physiological and pathological hematopoiesis through remodeling the ECM in BM hematopoietic microenvironment. In this review, we will focus on the roles of MMPs in physiological hematopoiesis, hematopoietic stem cells mobilization/transplantation, and hematological malignancies. Furthermore, the preclinical studies on the role of synthetic MMP inhibitors in the treatment of hematological malignancies will be discussed.     

Some considerations about the postglacial history and recent distribution ofFagus sylvatica in the NW Iberian Peninsula

This paper presents a re-assessment of the evidence of beech (Fagus sylvatica) presence on the NW Iberian Peninsula in the different stages of the Late Quaternary. For this purpose, numerous pollen diagrams were re-examined and the present-day distribution of the species was documented. Beech pollen has been recorded in different periods, before the Würm Pleni-Glacial, during the Late Glacial and the Holocene, leading to the hypothesis that there existed local refugia forFagus sylvatica in the NW Iberian Peninsula, comparable to those in more eastern areas of southern Europe, the existence of which has been recognized.