Indometofen causes biochemical changes in the blood cells characteristic for a radioresistant state of the body

The DNA and RNA contents, RNA/DNA ratio, and spontaneous and latex-induced oxidant activity indices of the whole blood were studied in the nitroblue tetrazolium test of mono- and polymorphonuclear blood leucocytes of intact dogs after injection of lipopolysaccharide pyrogenal. Significant changes in the above parameters were revealed for radioresistant (survived) and radiosensitive (lost) animals exposed to a subsequent prolonged gamma irradiation with a lethal dose of 7.64 Gy (LD75/45). Peroral introduction of 30 mg/kg indometofen (an indole analog of tamoxifen), which is a potential radioprotector, to dogs increased the survival rates of the irradiated dogs up to 93% and aided in the adaptive biochemical changes in the nuclear cell compartment of blood to induce a radioresistant status of the organism.     

Drug release from hydrophilic matrices. 1. New scaling laws for predicting polymer and drug release based on the polymer disentanglement concentration and the diffusion layer

Two scaling laws for predicting polymer and drug release profiles from hydrophilic matrices were developed. They were developed on the basis of the diffusion layer and the polymer disentanglement concentration, rho p,dis, the critical polymer concentration below which polymer chains detach off a gelled matrix that is undergoing simultaneous swelling and dissolution. The relation between rho p,dis and molecular weight, M1 for (hydroxypropyl)methylcellulose (HPMC) in water was established as rho p,dis (g/mL) varies M-0.8. This power-law relationship for rho p,dis, along with the diffusion layer adjacent to the gelled matrix, leads to the scaling law of mp(t)/mp(infinity) varies Meq-1.15, where mp(t)/mp(infinity) is the fractional HPMC release. The scaling law explains the observation that polymer and drug release rates decreased sharply with M at low M and approach limiting values at high M. Experimentally, mp(t)/mp(infinity) was found to scale with Meq as mp(t)/mp(infinity) varies Meq-0.93, where Meq is the equivalent matrix molecular weight. Moreover, fractional drug release, md(t)/md(infinity), followed Meq as md(t)/md(infinity) varies Meq-0.48. These two scaling laws imply that, if the release profiles are known for one composition, release profiles for other compositions can be predicted. The above two power laws lead to two master curves for mp(t)/mp(infinity) and md(t)/md(infinity), suggesting that the release mechanism for soluble drugs from HPMC matrices is independent of matrix compositions, presumably via a diffusion-controlled process. Limitations of the power laws are discussed.     

New ribosome-inactivating proteins with polynucleotide:adenosine glycosidase and antiviral activities from Basella rubra L. and bougainvillea spectabilis Willd

New single-chain (type 1) ribosome-inactivating proteins (RIPs) were isolated from the seeds of Basella rubra L. (two proteins) and from the leaves of Bougainvillea spectabilis Willd. (one protein). These RIPs inhibit protein synthesis both in a cell-free system, with an IC50 (concentration causing 50% inhibition) in the 10(-10) M range, and by various cell lines, with IC50S in the 10(-8)-10(-6) M range. All three RIPs released adenine not only from rat liver ribosomes but also from Escherichia coli rRNA, polyadenylic acid, herring sperm DNA, and artichoke mottled crinkle virus (AMCV) genomic RNA, thus being polynucleotide:adenosine glycosidases. The proteins from Basella rubra had toxicity to mice similar to that of most type 1 RIPs (Barbieri et al., 1993, Biochim Biophys Acta 1154: 237-282) with an LD50 (concentration that is 50% lethal) < or = 8 mg.kg-1 body weight, whilst the RIP from Bougainvillea spectabilis had an LD50 > 32 mg.kg-1. The N-terminal sequence of the two RIPs from Basella rubra had 80-93% identity, whereas it differed from the sequence of the RIP from Bougainvillea spectabilis. When tested with antibodies against various RIPs, the RIPs from Basella gave some cross-reactivity with sera against dianthin 32, and weak cross-reactivity with momordin I and momorcochin-S, whilst the RIP from Bougainvillea did not cross-react with any antiserum tested. An RIP from Basella rubra and one from Bougainvillea spectabilis were tested for antiviral activity, and both inhibited infection of Nicotiana benthamiana by AMCV.     

The effect of the Russian inhalant glucocorticosteroid budesonide on bronchial inflammation and hyperreactivity during the long-term treatment of bronchial asthma patients

11 patients with severe bronchial asthma entered a randomized trial of glucocorticosteroid budesonide of Russian produce. Of them 6 patients received inhalations of budesonide (800 micrograms/day for 6 months), 5 control patients did not receive the drug. As shown by investigations of external respiration and bronchoalveolar lavage with estimation of cytogram, metacholine provocative tests, fiber bronchoscopy, budesonide inhalations relieved clinical symptoms of asthma, bronchial hyperreactivity and inflammation.     

The frequency of illegitimate V(D)J recombinase-mediated mutations in children treated with etoposide-containing antileukemic therapy

Etoposide is among the most widely used anti-cancer drugs. Its use, however, has been associated with increased risk of secondary acute myeloid leukemia (AML) which is characterized by chromosomal translocations suggesting involvement of recombination-associated motifs at the breakpoints. A PCR-based assay was developed to quantitate the frequency of two illegitimate V(D)J recombinase-mediated genomic rearrangements-a 20-kb deletion in the hprt gene and the bcl2/IgH translocation (t(14;18)) found in non-Hodgkin's lymphoma. We examined both lymphocyte and non-lymphocyte blood cell DNA of children with acute lymphoblastic leukemia (ALL) for changes in the frequencies of these biomarkers during etoposide therapy to determine the level of illegitimate V(D)J recombination changes during therapy. A low level of t(14;18) was found in the lymphocytes before etoposide treatment, which was significantly reduced during etoposide therapy. In before-etoposide samples, no t(14;18) were found among 7.72x107 non-lymphocytes; during treatment none were found among 1.87x108 non-lymphocytes. Deletions were not found before etoposide treatment in either the lymphocytes (6.67x107) or non-lymphocytes (5.43x107) and were non-significantly elevated during etoposide therapy (1 in 1.4x108 lymphocytes and 1 in 1.39x108 non-lymphocytes). It is interesting to note the one patient with an hprt deletion mutation in non-lymphocytes; V(D)J recombination is not normally found in this cell type, but is the cell type from which AML derives. Several patients had clones of t(14;18)-bearing cells as determined by DNA sequence analysis. These results suggest that this etoposide-based chemotherapy was ineffective in producing genomic rearrangements mediated by illegitimate V(D)J recombination in these patients.     

Homology between the seed cytolysin enterolobin and bacterial aerolysins

Enterolobin, a 55-kDa cytolytic, inflammatory, and insecticidal protein isolated from seeds of the Brazilian tree Enterolobium contortisiliquum (Leguminosae-Mimosoideae) has been further purified and partially sequenced by using both manual and automated methods. A computational search of enterolobin partial amino acid sequence against the PIR database revealed possible sequence similarities with aerolysins, cytolytic proteins from Aeromonas species. An alignment of enterolobin partial sequence to the amino acid sequences of A. hydrophila and A. sobria aerolysins showed several similar regions with many residue identities. The seed protein enterolobin and the bacterial aerolysins may be homologous proteins despite the distant phylogenetic relationship.     

Infarct limitation of the second window of protection in a conscious rabbit model

Comparative cell transfer experiments have revealed that, despite their equal immune deficiency, C3H/SCID mice were markedly inferior compared with C.B-17/SCID mice in their ability to accept allogeneic and xenogeneic grafts. Allogeneic C.B-17/SCID bone marrow cells were engrafted poorly compared with syngeneic C3H/SCID when transplanted into C3H/SCID recipients, whereas cells of both strains were equally well engrafted into C.B-17/SCID mice. C.B-17/SCID mice were much more permissive for outgrowth of human Burkitt lymphoma (Raji), as well as for Epstein-Barr virus lymphoma development after transplantation of human peripheral blood lymphocytes. Human skin grafts were accepted by the C.B-17/SCID mice but were promptly rejected by the C3H/SCID mice. The resistance to human RaJi cells could be adoptively transferred by infusion of C3H/SCID splenocytes into C.B-17/SCID mice. Because the C.B-17/SCID and C3H/SCID mice equally lack both T and B lymphocytes, the latter may provide a relevant model for studies of non-T mechanisms of allograft or xenograft rejection.     

Expression of lysyl oxidase from cDNA constructs in mammalian cells: the propeptide region is not essential to the folding and secretion of the functional enzyme

Rat aortic lysyl oxidase cDNA was expressed under a metallothionein promoter in Chinese hamster ovary cells using a dihydrofolate reductase selection marker. One methotrexate-resistant cell line, LOD-06, generated by transfecting with full-length cDNA, yielded lysyl oxidase proteins consistent with the 50 kDa proenzyme and a 29 kDa mature catalyst. A second cell line, LOD32-2, was generated by transfection with a truncated cDNA lacking sequences which code for the bulk of the propeptide region. Both cell lines secreted apparently identical, 29 kDa forms of mature lysyl oxidase each of which catalyzed the deamination of human recombinant tropoelastin and alkylamines, consistent with the known specificity of lysyl oxidase. The secreted enzyme forms were inhibited by chemical inhibitors of lysyl oxidase activity, including beta-aminopropionitrile, phenylhydrazine, ethylenediamine, alpha, alpha'-dipyridyl, and diethyldithiocarbamate. Sensitivity to these agents is consistent with the presence of copper and carbonyl cofactors in the expressed enzymes, characteristic of lysyl oxidase from connective tissues. These results indicate the lack of essentiality of the deleted proprotein sequence for the proper folding, generation of catalytic function, and secretion of lysyl oxidase.     

Do dual nucleoside regimens have a role in an era of plasma viral load-driven antiretroviral therapy?

This study was undertaken to characterize predictors of response to double nucleoside combinations among 245 human immunodeficiency virus-infected persons initiating antiretroviral therapy. The median time for receiving antiretroviral therapy in this group was 6 months, and the plasma virus load was 58,000 copies/mL. The most commonly prescribed regimens were zidovudine/lamivudine (154 subjects, 63%) and stavudine/lamivudine (46 subjects, 19%). A total of 96 (39%) subjects had their virus load decrease to < 500 copies/mL after the initiation of therapy. Of the 245 study subjects, 102 (41.6%) had > or = 5 months of follow-up and two or more consecutive virus load determinations performed after the start of antiretroviral therapy. Multivariate analysis demonstrated that baseline virus load was the only significant factor associated with obtaining two or more plasma virus loads of < 500 copies/mL. Overall, these data demonstrate that dual nucleoside therapy (using currently licensed agents) cannot reliably achieve a high level of suppression of plasma virus load.     

Adherence to guidelines for the prevention of HIV-related respiratory diseases

In this study we characterized the pattern of use of preventive therapies for specific respiratory diseases within a cohort of homosexual men and assessed the impact of targeted feedback on the level of compliance with guidelines for these diseases. All human immunodeficiency virus seronegative (HIV-) (n=169) and acquired immune deficiency syndrome (AIDS)-free human immunodeficiency virus seropositive (HIV+) (n=154) participants in our cohort, who completed four annual visits between October 1989 and December 1993, were identified. Information about the use of purified protein derivative (PPD) (tuberculin) testing, history of pneumococcal vaccinations, influenza vaccinations, use of Pneumocystis carinii pneumonia (PCP) prophylaxis, symptoms and CD4 counts was obtained yearly for each subject. In 1992, participating physicians were provided with feedback regarding the overall levels of compliance with contemporary guidelines for the prevention of respiratory disease. As part of this exercise, the guidelines were distributed and discussed. The percentage of HIV+ patients who underwent PPD testing increased from 43 to 65% during the study (p=0.001). Significantly more HIV+ than HIV- patients underwent PPD testing (p<0.001). A total of 144 (94%) HIV+ men received at least one influenza vaccination compared to 60 (35%) HIV- men (p<0.001). Utilization of influenza vaccination in the HIV+ group significantly increased from 78% in 1992 to 92% in 1993 (p<0.001). A total of 104 (68%) HIV+ men received pneumococcal vaccination compared to 2 (1%) HIV- men (p<0.001). Among HIV+ individuals whose absolute CD4+ count was less than 200 cells x mm(-3), the percentage of men who received primary PCP prophylaxis was 0, 86, 72 and 88 for the years 1990-1993, respectively. Among HIV+ patients whose only eligibility criterion for PCP prophylaxis was a CD4+ percentage <20%, compliance was 55, 30, 37 and 50% for the years 1990-1993, respectively. Among HIV+ subjects, increases in the compliance level were noted for all preventive therapies after targeted feedback was provided during the last quarter of 1992. However, only utilization of influenza vaccine exceeded a 90% compliance in 1993. These data demonstrate that a suboptimal level of compliance with current guidelines for the prevention of respiratory disease among human immunodeficiency virus-infected individuals can be significantly improved using targeted feedback. Although it is likely that similar effects could be achieved in other populations or the community at large, this remains to be demonstrated.