Mechanisms of connective tissue damage by crystals containing calcium

From available clinical, radiographic, and synovial fluid findings, coupled with in vivo radiolabelled crystal turnover data and in vitro experimental data, a hypothesis has been formulated relative to the pathogenesis of BCP crystal deposition diseases (Fig. 2). Synovial lining cells phagocytose BCP crystals and particulate collagens in the joint fluid. During and/or after internalization these cells are stimulated in a variety of ways: 1) protease synthesis and secretion is relentlessly stimulated, which may damage joint tissues producing clinically evident loss of collagenous tissues including cartilage, bone, and tendon, and which may release additional amounts of crystals and particulate collagens into the synovial fluid, completing a vicious cycle; 2) PGE2 production is greatly augmented; 3) DNA synthesis is stimulated as a result of increased inositol phospholipid turnover and intracellular crystal dissolution. The increased number of synovial cells also augments the total local generation of proteases and prostenoids. Mechanical factors such as trauma or joint overuse also contribute to the pathogenesis of joint destruction as discussed in the article on the clinical aspects of BCP crystal deposition.     

Frequent ongoing T-cell receptor rearrangements in childhood B- precursor acute lymphoblastic leukemia: implications for monitoring minimal residual disease

Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.     

Development of cardiac sympathetic and adrenal-medullary responses in borderline hypertensive rats

Borderline hypertensive (BHR) rats are the first generation offspring of a cross of spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) normotensive rats. In adulthood, BHRs have systolic blood pressures in the 140-160 mm Hg range. If subjected to chronic stress paradigms, however, BHRs develop sustained and permanent elevations in systolic blood pressure (180-200 mm Hg). In the present study, we examined the functional development of cardiac and adrenal medullary responses to reflex activation of the sympathetic nervous system in preweanling BHR and WKY rats. Pups of the two groups were injected with insulin or saline at 4, 8, 12, or 16 days of age and sacrificed 3 h later. Insulin produces an acute lowering of blood glucose which is attended by a centrally mediated increase in sympathetic activity. The induction of ornithine decarboxylase (ODC) activity in heart and the depletion of epinephrine from the adrenal medulla were biochemical indicators of functional sympathetic neurotransmission. WKY and BHR pups had similar levels of cardiac ODC activity under basal conditions and following administration of insulin. In contrast, BHRs had higher amounts of adrenal norepinephrine and epinephrine from 4 to 16 days of age and greater depletion of adrenal epinephrine following insulin administration at 8, 12 and 16 days of age. These findings indicate that BHRs have a greater capacity for catecholamine biosynthesis, storage and release in the adrenal medulla during the preweanling period compared to age-matched normotensive WKY controls. This alteration in the adrenal medulla during the preweanling period may contribute to the susceptibility of adult BHR rats to stress-induced hypertension.     

Postoperative radiotherapy for locally advanced colon cancer

Background: The role of adjuvant postoperative radiotherapy for locally advanced colon cancer is not well documented. Methods: Seventy-eight patients who underwent a complete resection of B2-C colon cancer received postoperative radiotherapy. Twenty-eight patients received ⩽45 Gy; 50 patients received 50–55 Gy. Twenty-seven patients received adjuvant fluorouracil-based chemotherapy. All patients were followed for a minimum of 3 years; no patients were lost to follow-up. Results: The overall local control rate was 88%. The 5-year actuarial rate of local control was 96% after 50–55 Gy postoperative radiotherapy compared with 76% after <50 Gy (p=0.0095). Multivariate analysis of local control showed that only radiotherapy dose significantly influenced this end point. Cause-specific survival rates at 5 years were B2, 67%; B3, 90%; C1, 100%; C2, 61%; C3, 36%; and overall, 63%. Multivariate analysis of cause-specific survival showed that only stage significantly influenced this end point. Bowel obstruction caused by adhesions developed in three patients and required a laparotomy; radiation-induced sarcoma developed in one additional patient. Conclusions: Postoperative radiotherapy appears to reduce the risk of local recurrence in patients with locally advanced colon cancer. The optimal dose is probably 50–55 Gy at 1.8 Gy per fraction. Postoperative radiotherapy may improve cause-specific survival for patients with stages B3 and C2 cancers.     

Evidence for the causal role of endogenous interferon-alpha/beta in the regulation of angiogenesis,tumorigenicity, and metastasis of cutaneous neoplasms

Primary tumor growth and metastasis depend on angiogenesis, which is determined by the balance between proangiogenic and antiangiogenic molecules. Interferon (IFN)-α and -β inhibit angiogenesis through downregulation of interleukin-8, matrix metalloproteinase-9, and basic fibroblast growth factor. To provide evidence for the causal role of IFN-α/β in the induction of neoplasms, their angiogenesis, and hence, progressive growth, we carried out experiments using 129S6 IFN-α/β receptor −/− mice back-crossed to BALB/c nude mice. Subcutaneous angiogenesis was determined following implantation of gelfoam sponges containing 0.4% agarose and several proangiogenic molecules. Tumorigenicity and production of lung metastasis were determined subsequent to subcutaneous and intravenous injections, respectively, of highly metastatic A375SM human melanoma cells. Carcinogenesis was induced by chronic exposure of mice to UVB radiation (5 kJ/m², 3 times/week). Angiogenesis, tumorigenicity, and production of metastasis, as well as development of autochthonous skin tumors, were all accelerated in IFN-α/β receptor −/− mice as compared to control mice. Collectively, the data show that inability to respond to endogenous IFN-α/β (through a mutation in the IFN-α/β receptor) leads to increased susceptibility to carcinogenesis, enhanced angiogenesis, tumorigenicity, and metastasis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Spermicidal activity of chelated complexes of bis(cyclopentadienyl)vanadium(IV)

Transition metal complexes containing vanadium IV have been shown to modulate the cellular redox potential and catalyse the generation of reactive oxygen intermediates (ROI). Since sperm function is exquisitely susceptible to ROI, we examined the effects of stable chelate complexes of vanadocenes on human sperm motility. We synthesized seven structurally distinct chelate complexes of bis(cyclopentadienyl)vanadium(IV) with bidentate ligands [i.e. vanadocene acetylacetonato monotriflate (VDacac), vanadocene hexafluoro acetylacetonato monotriflate (VDHfacac), vanadocene N-phenyl benzohydroxamato monotriflate (VDPH), vanadocene acethydroxamato monotriflate (VDH), vanadocene catecholate (VDCAT), vanadocene bipyridino ditriflate (VDBPY), and vanadocene dithiocarbamate monotriflate (VDDTC)], and evaluated their spermicidal activity using computer-assisted sperm analysis (CASA; Hamilton-Thorne). All seven chelate complexes of vanadocene elicited potent spermicidal activity at micromolar concentrations (EC50 values: 3.9-106 microM) without affecting the sperm acrosome integrity. The catecholate and acetylacetonate complexes of vanadocene were the most active and the bipyridyl complex the least active with an order of efficacy VDCAT > VDacac > VDDTC > VDPH > VDH > VDHfacac > VDBPY. The spermicidal activity of chelate complexes of vanadocenes was rapid and irreversible since the treated spermatozoa underwent apoptosis, as determined by the flow cytometric analysis of mitochondrial membrane potential, surface annexin V binding assay, in-situ nick-end labelling of sperm nuclei, and confocal laser scanning microscopy. These results provide unprecedented evidence that chelate complexes of vanadocene with bidentate ligands have spermicidal and apoptosis inducing properties. These vanadocene complexes, especially VDacac, may be useful as contraceptive agents.      

Aspartylglucosaminuria in the United States

Aspartylglucosaminuria (AGU) was diagnosed in two unrelated males with progressive mental retardation, coarse facies and skeletal abnormalities. Until now, this disorder has been described in predominantly Finnish populations with only one previous case reported in the U.S. We conclude that AGU may be more common in nowFinnish populations than the number of reported cases would indicate and should be included in the differential diagnosis in patients with suspected lysosomal storage disorders regardless of their geographical or ethnic backgrounds.