The accuracy and reliability of a novel handheld dynamic indentation probe for analysing articular cartilage

This study investigates the accuracy and reliability of a novel handheld indentation system designed to ascertain the dynamic biomechanical properties of articular cartilage. A series of standard elastomers were assessed with both the handheld indentation system and a bench-top dynamic indentation system to assess the accuracy of the instrument. Interoperator and intraoperator experiments were undertaken to investigate the reliability of the system when used by an individual operator and by five different operators. Intraclass coefficients (Rho) were derived using a random effects model. The system was then used to ascertain the topographical variation in the shear moduli and phase lag of articular cartilage across normal ovine tibial plateaux. The system was shown to be highly accurate (R2 = 0.97), and had excellent reliability when measuring the dynamic shear modulus of articular cartilage (interoperator Rho = 0.75, intraoperator Rho = 0.79). Measurement of static shear modulus was less reliable (interoperator Rho = 0.15, intraoperator Rho = 0.52), but may be improved by monitoring the load applied to the instrument by the operator. The instrument was used to differentiate between different regions of cartilage and generated a topographical map of an ovine tibial plateau. The cartilage located beneath the menisci was 200-500% stiffer than the cartilage that was not covered by the menisci, while the phase lag was almost constant (10+/-2 SD) over the entire tibial plateau. The system was shown to be an accurate and reliable tool for rapidly assessing the dynamic biomechanical properties of articular cartilage, while being small enough to be used arthroscopically.     

Multilineage potential of homozygous stem cells derived from metaphase II oocytes

Human stem cells derived from human fertilized oocytes, fetal primordial germ cells, umbilical cord blood, and adult tissues provide potential cell-based therapies for repair of degenerating or damaged tissues. However, the diversity of major histocompatibility complex (MHC) antigens in the general population and the resultant risk of immune-mediated rejection complicates the allogenic use of established stem cells. We assessed an alternative approach, employing chemical activation of nonfertilized metaphase II oocytes for producing stem cells homozygous for MHC. By using F1 hybrid mice (H-2-B/D), we established stem cell lines homozygous for H-2-B and H-2-D, respectively. The undifferentiated cells retained a normal karyotype, expressed stage-specific embryonic antigen-1 and Oct4, and were positive for alkaline phosphatase and telomerase. Teratomatous growth of these cells displayed the development of a variety of tissue types encompassing all three germ layers. In addition, these cells demonstrated the potential for in vitro differentiation into endoderm, neuronal, and hematopoietic lineages. We also evaluated this homozygous stem cell approach in human tissue. Five unfertilized blastocysts were derived from a total of 25 human oocytes, and cells from one of the five hatched blastocysts proliferated and survived beyond two passages. Our studies demonstrate a plausible "homozygous stem cell" approach for deriving pluripotent stem cells that can overcome the immune-mediated rejection response common in allotransplantation, while decreasing the ethical concerns surrounding human embryonic stem cell research.     

Hemopoietic stem cell transplantation in rheumatic diseases--an update

Hematopoietic stem cell transplant (HSCT) for autoimmune diseases has been recognized as a potential treatment for patients who have failed conventional therapy. Autologous (self) donor cells have been preferred over allogeneic (HLA-matched) cells for rescue after high dose immunotherapy, given the previous higher rates of mortality, graft versus host disease (GVHD), and the need for more intense myeloablation associated with the latter. The European Group for bone Marrow Transplantation in Basel Switzerland (EBMT) and various groups within the US funded by the NIH (including the Autologous Blood and Marrow Transplant Registry (ABMTR)) have been pivotal in maintaining registries on patients transplanted as well as promoting homogeneity for future studies including Rheumatoid Arthritis (RA), Systemic Lupus Erythematosus (SLE) and Systemic Sclerosis (SSc). Although, patients transplanted for RA show initial success, relapse of the disease is common. In many, however, a second positive result can be obtained with the addition of DMARD therapy to which they were previously unresponsive, suggesting a "debulking" of disease by HSCT. SLE patients also have a high rate of success after HSCT, although current mortality rates appear high. Transplant in SSc patients has offered durable responses with improving transplant-related mortality related to careful patient selection.     

Course of bipolar disorder in eastern India.

The life course of affective episodes was determined for 95 consecutively admitted patients from eastern India fulfilling RDC criteria for definite mania during the current episode, using SADS-L interviews. There was a significantly greater frequency of manic compared to depressive relapses. Presentation as recurrent mania was very common. The total numbers of affective and manic episodes were significantly higher among those with recurrent mania and in cases where the first illness episode was manic.