In vivo evaluation and comparison of collagen, acetylated collagen and collagen/glycosaminoglycan composite films and sponges as candidate biomaterials

Native collagen, acetylated collagen, collagen/10% chondroitin sulphate, collagen/2.5% hyaluronic acid and collagen/20% hyaluronic acid were implanted both as film and as sponge into rat lumbar muscle for 7 and 14 d. After 7 d implantation, all materials elicited an acute inflammatory cell response characterized by numerous polymorphs and histocytes. The cell population after 14 d was principally mononuclear, i.e. leucocytes, neutrophils, macrophages, lymphocytes and fibroblasts. Both films and sponges followed a similar pattern. Native collagen elicited a subacute inflammatory response after 7 d. However, 14 d after implantation, a marked infiltration by neutrophils was apparent with subsequent degradation of existing collagen material. Acetylated collagen film evoked a much greater inflammatory cell response than native collagen. Both collagen/hyaluronic acid composites elicited a similar response. The collagen/10% chondroitin sulphate composite elicited the least inflammatory cell response at 7 d, whereas infiltration by host fibroblasts after 14 d implantation was clearly seen.     

Amino acid composition in Isoparorchis hypselobagri

Summary The free amino acids of Isoparorchis hypselobagri have been determined by the chromatographic method (two-dimensional ascending). These are: leucine, valine, proline, alanine, glycine, glutamic acid and aspartic acid.     

Chromosomal anomaly of 6q in chronic myelogenous leukemia (CML)

Anomalies of chromosome 6q, along with other chromosomal anomalies, are described in the bone marrow cells of two patients with chronic myelogenous leukemia (CML). One patient, a 14-year-old male, developed the karyotype 46,XY,t(1;6)(p36;q15),del(3)(q25),del(17)(p11),? inv(17)(q12q24) during blastic crisis of his disease. The other patient, a 24-year-old male, had the karyotype 46,XY,del(6)(q13),t(9;22)(q34;q11) during the early phase of his disease and evolution of i(17q) in the karyotype late in the disease.     

Identification of a 25-kilodalton protein of Mycobacterium bovis BCG to distinguish BCG strains from Mycobacterium tuberculosis.

Mycobacterium bovis BCG vaccine strains were compared with Mycobacterium tuberculosis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A 25-kDa protein observed in the BCG strains was absent in M. tuberculosis. Rabbit antibodies specific to the 25-kDa protein uniquely identified this protein in BCG strains but not in M. tuberculosis. It is suggested that the 25-kDa protein and polyclonal antibodies directed against this antigen can be exploited to distinguish BCG strains from M. tuberculosis.     

Proteins with molecular masses of 25 to 40 kilodaltons elicit optimal protective responses against Plasmodium chabaudi adami infection.

The presence of the CD4+ T cell has been shown to be crucial for resolution of acute infection in the Plasmodium chabaudi adami murine malaria model. This model is, therefore, suitable for the isolation of malaria antigens that are capable of activating protective T cells. In light of this, we set out to identify P. chabaudi adami molecules that activate protective responses in this model. Denatured P. chabaudi adami proteins were isolated by continuous-flow electrophoresis on the basis of their apparent molecular masses and then sequentially assessed for the ability to protect mice in immunization experiments. We report here that low-molecular-mass P. chabaudi adami polypeptides in the range from 25 to 40 kDa are most effective at immunizing mice against a challenge infection with viable P. chabaudi adami. The method used to obtain these proteins could also be applied to identify molecules that activate protective cell-mediated responses in other infectious disease models.     

Soluble Fas and soluble Fas ligand proteins in human milk: possible significance in the development of immunological tolerance

Human milk contains a complex uncharacterized, immune system able to exert actions both locally and systemically. This study reports the results of an ELISA-based quantitation of soluble Fas and soluble Fas ligand in human milk which may modulate the Fas/FasL system that is critical for the expression of immune tolerance and apoptosis. Production of Fas/FasL mRNAs by milk cells was also examined using RT-PCR. Fas is ubiquitously expressed in various cells and when bound by its ligand FasL, present predominantly on activated T- and NK cells, Fas-expressing cells are killed. A large amount of soluble Fas (1746-4320 pg/ml) is detected in colostrum, transitional milk and the mature milk of mothers delivering prematurely or at full-term, whereas FasL is present only in the range 123-310 pg/ml. Milk cells are positive for Fas mRNA, but negative for FasL mRNA. An excess of soluble Fas in human milk may bind to FasL preventing apoptosis and preserving epithelial barriers, and may represent an additional new mechanism whereby human milk favours immune tolerance and normal gastrointestinal development.