Molecular recognition in the minor groove of the DNA helix. Studies on the synthesis of oligonucleotides and polynucleotides containing 3-deaza-2'-deoxyadenosine. Interaction of the oligonucleotides with the restriction endonuclease EcoRV

An improved procedure for the preparation of 3-deaza-2'-deoxyadenosine (d3CA) is described which is suitable for the synthesis of gram quantities of this analogue. Using phosphoramidite chemistry d3CA has been incorporated into the Eco RV restiction endonuclease recognition sequence (underlined) present in the self-complementary dodecamer d(GACGATATCGTC). The modified oligonucleotides have been thoroughly characterised by nucleoside composition analysis, circular dichroism and thermal melting studies. Studies with Eco RV show that incorporation of d3CA into either the central or outer dA-dT base-pair results in a substantial reduction in the rate of cleavage. The two-step conversion of d3CA to 3-deaza-2'-deoxyadenosine-5'-O-triphosphate (d3CATP) via the 5'-O-tosylate is also described. d3CATP is not a substrate in the poly[d(AT)].poly[d(AT)] primed polymerisation for either E. coli DNA polymerase I or Micrococcus luteus DNA polymerase. In a more detailed kinetic analysis d3CATP was shown to be a competitive inhibitor of E. coli DNA polymerase I with respect to dATP.

Plant regeneration from cotyledon protoplasts of Xinjiang muskmelon

Cotyledon protoplasts were isolated from seedlings of Xinjiang muskelon (Cucumis melo var.saccharinus) grown under sterile conditions and cultured in modified Miller medium. High frequency division of the protoplast-derived cells was observed. Agarose bead culture with B6S3 tobacco crown gall nurse cells was found most suitable for the cotyledon protoplasts when compared with other culture methods. Intact plants were regenerated from the protocalli by a two-step culture procedure with liquid and then solid media.

Dibenzocycloalkenimine (MK-801) stimulates phosphoinositide hydrolysis in rat cerebral cortical slices)

Dibenzocycloalkenimine (MK-801), a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, induced a concentration-dependent accumulation of inositol monophosphate in rat cerebral cortical slices. This effect appears unrelated to antagonism of NMDA receptors as AP-7 and PCP did not cause comparable effects. In addition, the MK-801-induced response was unaffected by NMDA or glycine, alone or in combination, Zn2+, or the removal of Mg2+ from the buffer. These results indicate a novel site of action for MK-801 associated with activation of phosphoinositide hydrolysis.

[Adult diarrhea rotavirus in Jilin, China]

In May 1986, an outbreak of epidemic acute diarrhea occurred in one city and three counties in Yanbian area. The diarrheal cases were seen in all age groups, the majority of the cases were seen in adult age group. No bacterial pathogens were isolated in 22 fecal samples examined, however rotavirus like particles of 52-68 nm in diameter were found in 50% (11/22) of fecal samples by the immunoelectron microscopy using convalescent sera. Examination by the adult diarrhea rotavirus (ADRV) ELISA kit showed positive reaction in 86% (6/7) of fecal extracts, however in all 22 fecal extracts examination using ELISA kit for detection of group A rotavirus showed negative reaction. The PAGE patterns of viral RNAs similar to those of ADRV were seen in 13 out of 22 fecal extracts. The detection rate by PAGE analysis was 59%. Based on the above data, the etiological agent of the epidemic acute diarrhea, which occurred in Yanbian area, was identified to be ADRV.

[Active oxygen radicals produced by the leukocytes in patients with malignant lymphoma]

The electron spin resonance (ESR) spectra of the active oxygen radicals produced during the respiratory burst of PMA-stimulated leukocytes and the oxygen consumption were studied with ESR spin trapping technique and spin probe oximetry for 31 times in 17 cases of malignant lymphoma. The results showed that the spectra produced from the PMA-stimulated patients' leukocytes were dominantly spin adducts of DMPO-hydroxyl radicals, DMPO-OH; and the decrease of oxygen consumption during respiratory burst suggested that the function on respiratory burst, was inhibited. From the results of kinetic observations of the patients conditions, it was shown that the respiratory burst and oxygen consumption were improved, even close to normal, when the patient's condition was in remission or amelioration. This paper is the first to report the active oxygen radicals produced from malignant lymphoma patient's leukocytes with ESR. This is helpful for a better understanding of the mechanism of cancerous proliferation and metastasis.

[The measurement of radial bone mineral content in children]

The bone mineral contents of radius of 255 boys and 243 girls (7 to 16 year old of the Han nationality, living in Chengdu) were measured with Bone Mineral Analyzer (Type:SPA-I). The standard values of g/cm was made. There was a positive correlation between the value in boys or girls and chronological age, height or weight. The coefficients were respectively 0.83, 0.77, 0.64 in boys and 0.82, 0.82, 0.82 in girls (P less than 0.005). At the age of 13 (in boys or in girls) the value of the g/cm was the highest.

Synthesis and antimalarial activity of (+)-deoxoartemisinin

(+)-Deoxoartemisinin (2), a new and more active antimalarial agent, was successfully prepared from artemisinin in one step using NaBH4 and BF3.Et2O in THF. (-)-Deoxodeoxyartemisinin (5), a potential metabolite of deoxoartemisinin, was also prepared either from 2 or from artemisinic acid. 2 shows 8-fold increased antimalarial activity in vitro against chloroquine-resistant malaria as compared to artemisinin (1). Compound 2 possesses superior in vivo antimalarial activity to 1.

Ultrastructural morphogenesis of 4-ipomeanol-induced bronchiolitis and interstitial pneumonia in calves

The two objectives of this research were 1) to describe the ultrastructural morphogenesis of pulmonary damage and repair induced in calves after treatment with 4-ipomeanol and 2) to characterize infiltrating pulmonary inflammatory cells by bronchoalveolar lavage. Interstitial edema was observed as early as 4 hours after intravenous injection of 4-ipomeanol (5 mg/kg body weight) and progressed to severe alveolar edema by 72 hours. Damage to type I alveolar epithelial cells and terminal bronchiolar nonciliated cells included dilation of endoplasmic reticulum and perinuclear envelopes and was present at 4 hours after treatment. Necrosis and sloughing of these cells from basement membranes occurred at times from 12 to 96 hours after treatment. Alveolar capillary endothelial cells had mild dilation of endoplasmic reticulum at times from 12 to 72 hours after treatment. Necrosis of endothelial cells was not observed. Inflammatory cell infiltrates in bronchioles and alveoli were dominated by macrophages and neutrophils. Significant elevations (P less than 0.05) in numbers of neutrophils and macrophages were recovered by bronchoalveolar lavage at times from 24 to 96 hours after 4-ipomeanol-treatment. Hyperplasia of nonciliated bronchiolar epithelial cells and of type II alveolar epithelial cells were observed at 72 and 96 hours after treatment. The results indicate that type I alveolar epithelial cells and nonciliated bronchiolar epithelial cells are most susceptible to 4-ipomeanol-induced damage and necrosis in calves. 4-ipomeanol-induced pulmonary edema in calves occurs prior to ultrastructurally-demonstrable, mild, alveolar capillary endothelial cell damage.

[Determination of eucalyptole in eucalyptus oil by gas chromatography]

This paper reports the determination of eucalyptole in eucalyptus oil by gas chromatography. The results were similar to the specifications in the Chinese Pharmacopoeia. The method is simple, rapid, accurate and sensitive and requires only small amount of samples. The coefficient of variation is less than or equal to 0.52%.

Rare cavernous haemangioma of the hypopharynx with numerous phleboliths

Cavernous haemangiomata occur quite commonly, but one situated in the hypopharynx which contains as many as 240 phleboliths, as reported here, is a rare curiosity. The clinical manifestations, angiographic findings and the operative procedure of this case are described with a brief review of the formation of phleboliths in cavernous haemangiomas.

[Protective effects of Panax notoginseng saponins on experimental myocardial injury induced by ischemia and reperfusion in rat]

Effects of total saponins of Panax notoginseng (PNS) and purified ginsenosides Rb1 and Rg1 from PNS on myocardial injury induced by cardiac ischemia and reperfusion were studied with rat hearts in situ and in vitro. In pentobarbital-anesthetized rats, PNS pretreatment (100 and 200 mg/kg) provided significant reduction in myocardial infarct size after left descending coronary artery ligation (40 min) and reperfusion (120 min) in comparison with the control. PNS 12.5 and 25 mg/L, Rb1 10 mg/L, and Rg1 10 mg/L significantly decreased cardiac CPK release, attenuated myocardial Ca2+ accumulation, reduced malondialdehyde (MDA) production and prevented reduction of superoxide dismutase (SOD) activity in comparison with the control in perfused isolated rat hearts with global ischemia (40 min) and reperfusion (15 min). The results show that PNS, Rb1, and Rg1 prevent cardiac ischemia and the action is considered to be related to the inhibition of lipid peroxidation.

Polyclonal B cell activation of IgG2a and IgG2b production by infection of mice with lactate dehydrogenase-elevating virus is partly dependent on CD4+ lymphocytes

Concentrations of IgM and IgG isotypes were determined by capture ELISA in plasma of Swiss, BALB/c and C58/M mice. Plasma IgG isotype concentrations, especially of IgM, IgG1 and IgG2a, varied considerably between mouse strains, batches of mice of the same strain and individual mice and as a function of age. Infection of the mice with LDV, which is known to replicate primarily in a subpopulation of macrophages, consistently resulted in a rapid elevation of plasma IgG2a (or of IgG2b in some Swiss nu/+ mice), but no plasma IgG increases were observed in mice immunized with inactivated LDV. Plasma IgG2a elevation after LDV infection was greatly delayed and reduced by depletion of the mice of CD4+, but not of CD8+, T cells by administration of protein-G-purified anti-CD4 or anti-CD8 mAbs, and completely inhibited by repeated treatment of the mice with cyclophosphamide. Treatment with anti-CD4 mAbs, or cyclophosphamide also greatly reduced the production of anti-LDV antibodies, while not significantly affecting the replication of LDV in these mice. Nude Swiss mice also failed to produce anti-LDV antibodies, though supporting normal LDV replication. Plasma IgM, IgG1, IgG2a and IgG2b levels increased in LDV-infected nu/nu mice, but similar changes were observed in uninfected mice. The results indicate that the LDV-induced polyclonal activation of B cells requires productive LDV infection of mice and is, at least partly, dependent on functioning CD4+ cells. They suggest that productive infection of the LDV-permissive subpopulation of macrophages leads to the activation of CD4+ T lymphocytes of subset 1 and their Spleen cells from 5-day LDV-infected BALB/c mice incorporated [3H]thymidine 2-3 times more rapidly in vitro than spleen cells from companion uninfected mice, whereas their responses to concanavalin A and lipopolysaccharide were reduced 60-70%.

[The relation of vasoactive intestinal peptide and acute hypoxia]

In order to observe the effect of acute hypoxia on release of vasoactive intestinal peptide (VIP), the plasma VIP content was determined in anesthetized dogs by a specific radioimmunoassay technique during acute hypoxia. Blood gases and hemodynamics were monitored simultaneously. After inhalation of 10% oxygen. the plasma VIP levels elevated along with decrease in PaO2 and increase in pulmonary artery pressure. The plasma concentration of VIP in the portal vein increased significantly from 106 +/- 21 pg/ml before hypoxia to 173 +/- 36 pg/ml 15 minutes after the onset of hypoxia (P less than 0.01). The difference of arterio-venous VIP content increased from -3 +/- 6 pg/ml before hypoxia to +9 +/- 7 pg/ml after inhalation of 10% oxygen for 30 minutes. The results suggested that VIP was released from the gastrointestinal tract as well as from the lung in case of hypoxia and pulmonary hypertension. It is considered that the release of VIP may be an adaptive and compensatory response, promoting vasodilation and perfusion in vital organs.

Rotation invariant pattern recognition with a programmable joint transform correlator

A circular harmonic expansion filter is real value implemented in a joint transform correlatora rchitecturet o perform rotation invariant pattern recognition.

The effects of pH on hyaluronate as observed by light scattering

Hyaluronate was investigated over a wide pH range, and at near zero and intermediate ionic strength, using dynamic and total intensity light scattering. Commercially obtained rooster comb hyaluronate was purified, and solutions were prepared in pure water by low-power bath ultrasonication and subsequent filtering. These solutions were of low polydispersity and appeared to contain single molecules of hyaluronate. Despite the absence of added electrolyte, these solutions yielded well-behaved Zimm plots. Increasing ionic strength and changing pH decreased radii of gyration and increased diffusion constants. Except for what appeared to be slow hydrolysis at either extreme of pH, molecular weights remained constant under all pH and ionic strength conditions. Under all solvent conditions investigated, diffusion coefficients increased with decreasing hyaluronate concentration. Unsonicated, lightly centrifuged solutions without added electrolyte were polydisperse, and their light scattering intensity was dominated by what appeared to be stable hyaluronate aggregates. The results are interpreted in terms of the polyelectrolyte properties of hyaluronate and its tendency to form stable entanglements, especially at low ionic strength. Previous light scattering studies in the literature on hyaluronate have shown widely varying results. The present article briefly reviews this literature and attempts to explain the variation among the previous results, emphasizing the Kuhn statistical segment length as an indicator of whether results are influenced by polydispersity or contaminants causing hyaluronate aggregation.

In vivo interference by Newcastle disease virus in chickens, the natural host of the virus

Homologous and heterologous viral interference is a common occurrence that has been well studied in vitro. In the present study, homologous viral interference between the LaSota and NYP strains of Newcastle disease virus (NDV) was studied in vivo in chickens, the natural host for NDV. The LaSota strain is avirulent and widely used as a vaccine in poultry industry, while the NYP strain is highly virulent and causes acute disease and death in chickens within four to six days after infection. Chickens generally became resistant to NYP strain challenge 12 hours after intranasal or intratracheal inoculation with LaSota strain virus. The resistance was manifested by reduction in chicken morbidity and mortality, decrease in virus replication in the chicken respiratory tract (p less than 0.05), and inhibition of NYP strain induced gross and microscopic lesions. Interferon was first detected in the chicken respiratory tract and blood at 3 to 6 hours; it peaked at 12 to 24 hours and was maintained for 48 hours after viral inoculation, indicating that interferon induction might be one possible mechanism of the interference between the two strains. This study suggests a role for viral interference in vaccination against virulent viruses.