Elimination of malignant clonogenic cells from human bone marrow using multiple myeloid cell-specific monoclonal antibodies and complement.

Single or combined monoclonal antibodies (McAbs) Zh53, Zh820, and Zh2-1 have been used to eliminate malignant clonogenic cells from human bone marrow. The test of cytotoxicity showed that all of these McAbs could express high specific cytotoxic action against HL-60 cells and were selectively complement-dependent cytotoxic to various types of fresh leukemic cells. Clonogenic assay detected that single treatment with antibody and rabbit complement (RC) could reduce clonogenic units of HL-60 cells by more than 2 logs and two treatments reduced clonogenic units by more than 4 logs. However, combination of 2 McAbs could reduce clonogenic units by 4-5 logs. The data suggest that multiple treatments with McAbs and RC or a combination of 2 McAbs are more effective than a single treatment in eliminating clonogenic tumor cells. Treatment of normal human bone marrow with Zh53, Zh2-1 and RC did not produce a loss of normal CFU-GM, but treatment with Zh820 reduced the clonic units of normal CFU-GM by 24%.

     

Treatment of severe diarrhoeal dehydration in hospital and home by oral fluids

This paper reports on 1330 infants, from birth to 24 months old, suffering from diarrhoea and moderate to severe dehydration who were hospitalized in Tehran University Hospital over a period of 11 months. Fifteen per cent of them had signs of shock and 36% had marasmus. All patients were treated orally in two phases: rehydration therapy and maintenance therapy. For rehydration, an isotonic fluid (sodium 80 mmol l-1, potassium 20 mmol l-1) was administered at a rate of 40 ml kg-1 h-1 until all signs of dehydration disappeared. Following complete hydration, the patients were discharged and maintenance therapy was performed at home, by mothers, administering Maintenance Solution (sodium 40 mmol l-1, potassium 30 mmol l-1) ad libitum. Intravenous fluids were not used, even in severe dehydration. The efficacy and safety of this regimen were confirmed by rapid and successful rehydration in 99.7% of the patients and correction of a wide variety of electrolyte abnormalities present on admission, though some relapsed. The study suggests that this protocol could be employed in varied types and severities of dehydration and electrolyte abnormalities, and could also be used in both well nourished infants and in those with severe marasmus. It also demonstrates that mothers can serve as effective health workers and can perform successful maintenance therapy. Nine per cent of treated children required readmission to hospital within 24 h of discharge and a further 8% were hospitalized elsewhere with recurrent symptoms.     

T cells specific for alpha-beta interface regions of hemoglobin recognize the isolated subunit but not the tetramer and indicate presentation without processing.

Processing of a protein antigen into fragments is believed to be a prerequisite for its presentation by the antigen-presenting cell to the T cell. This model would predict that, in oligomeric proteins, T cells prepared with specificity for regions that are buried within subunit association surfaces should recognize the respective regions in vitro equally well on the isolated subunit or on the oligomer. Three hemoglobin (Hb) alpha-chain synthetic peptides, corresponding to areas that are situated either completely [alpha-(31-45)] or partially [alpha-(41-45) and alpha-(81-95)] within the interface between the alpha and beta subunits of Hb, and a fourth peptide representing a completely exposed area in tetrameric Hb were used as immunogens in SJL/J (H-2s) mice. Peptide-primed T cells were passaged in vitro with the respective peptide to obtain peptide-specific T-lymphocyte lines. T-cell clones were isolated from these lines by limiting dilution. T-cell lines and clones that were specific for buried regions in the subunit association surfaces recognized the free peptide and the isolated subunit but not the Hb tetramer. On the other hand, T cells with specificity against regions that are not involved in subunit interaction and are completely exposed in the tetramer recognized the peptide, the isolated subunit, and the oligomeric protein equally well. The responses of the T-cell lines and clones were major histocompatibility complex-restricted. Since the same x-irradiated antigen-presenting cells were employed, the results could not be attributed to differences or defects in Hb processing. The findings indicate that in vitro the native (unprocessed and undissociated) oligomeric protein was the trigger of major histocompatibility complex-restricted T-cell responses.     

Novel azapeptide inhibitors of cathepsins B and K. Structural background to increased specificity for cathepsin B

Abstract: We have designed and synthesized a new series of azapeptides which act as potential inhibitors of cathepsin B and/or cathepsin K. Their structures are based upon the inhibitory sites of natural cysteine protease inhibitors, cystatins. For the synthesized azapeptides, the equilibrium constants for dissociation of inhibitor–enzyme complex, K_i, were determined. Comparison of these values indicated that all of the azainhibitors act much stronger toward cathepsin B. Z‐Arg‐Leu‐His‐Agly‐Ile‐Val‐OMe ( 7 ) proved to be approximately 500 times more potent for cathepsin B than for cathepsin K. To be able to explain the obtained experimental values we used the molecular dynamics procedures to analyze the interactions between cathepsin B and compound 7 . We also determined the structure of the most potent and selective cathepsin B azainhibitor by means of NMR studies and theoretical calculations. In this report, we describe SAR studies of azapeptide inhibitors indicating the influence of the conformational flexibility of the examined compounds on inhibition of cathepsins B and K.     

Synthesis and anti-tuberculous activity of diesters based on isosteviol and dicarboxylic acids

Diesters based on isosteviol and dicarboxylic acids were synthesized and tested for antituberculous activity. Isosteviol and some of its derivatives exhibit appreciable tuberculostatic properties in vitro, the activity being dependent on the length of the polymethylene spacer connecting two ent-beyeran fragments. The mechanism of the antituberculous action of isosteviol derivatives are discussed. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 9, pp. 12–13, September, 2006.     

Evaluation of tissue response to MTA and Portland cement with iodoform.

OBJECTIVE: The aim of this study was to evaluate the biocompatibility of Portland cement with the addition of iodoform, compared to MTA (ProRoot). STUDY DESIGN: Eighteen Wistar albino rats were divided into 3 groups of 6 animals each. Polyethylene tubes were filled either with freshly mixed MTA or Portland cement mixed with iodoform (20% wt/wt) and implanted subcutaneously. An empty tube served as control. After 7, 30, or 60 days, the implants together with the surrounding tissues were removed in blocks. Sections were evaluated for the presence and thickness of a fibrous capsule, presence of granulation tissue, and the severity of inflammatory response. Data were submitted to nonparametric statistical analysis with individual comparisons between groups at a significance level of P < 0.05. RESULTS: There were no differences between inflammatory responses at 7 and 30 days. After 60 days from surgical removal, there was significantly more tissue reaction to the MTA and Portland cement compared to the control group. CONCLUSION: There were no significant differences regarding inflammatory responses between MTA and Portland cement with iodoform after 7, 30, or 60 days. After 60 days, the fibrous capsule around the Portland cement appeared more organized than tissue surrounding MTA implants. After 60 days, there was still a significantly increased tissue reaction to the 2 cements compared to the empty polyethylene tubes.     

Mycobacterium caprae in cattle and humans in Croatia.

SETTING: This paper describes an outbreak of human and related bovine tuberculosis (TB) caused by Mycobacterium caprae in Croatia. A 13-year-old boy clinically presented enlargement of cervical lymph node with consecutive isolation of M. caprae. His 7-year-old sister, who had no clinical signs of disease, hyper-reacted to the purified protein derivative (PPD) test (>25 mm) and peribronchial infiltration was found by radiology. The children came from a family that ran a small-sized cattle dairy farm. DESIGN: All cattle on the farm were subjected to cutaneous TB testing: six of the 14 reacted positive, while three were suspicious. The entire herd was slaughtered, their carcasses examined and collected material subjected to pertinent diagnostic procedures. RESULTS: Gross examination findings consistent with TB were observed in the PPD-positive cows. Mycobacteria isolated from the boy and cattle were identified by classical and molecular methods, confirming M. caprae as the causative agent. CONCLUSION: Although not bacteriologically proven, consumption of raw milk or non-pasteurised milk products from infected dairy cattle was suspected as the source of infection in humans. Our findings confirm the domination of M. caprae among cattle in Croatia and represent the first evidence of M. caprae infection in humans in Croatia.