Molecularly imprinted polymers from nicotinamide and its positional isomers

Imprinted polymers were prepared for nicotinamide and its positional isomers. The influence of porogenic solvent and functional monomer on recognition properties of the polymer was compared. The results indicated that two functional groups, the heterocyclic nitrogen and the amide group, in the nicotinamide or isonicotinamide molecule have a synergistic effect in binding to the polymer. The polymers prepared with nicotinamide and isonicotinamide can be used as HPLC stationary phase for the separation of positional isomers of nicotinamide or isonicotinamide, while the polymer prepared with picolinamide showed no specificity toward the template. The mechanisms for the differences in recognition are discussed. In addition to the retention of polymers to their templates the polymers also displayed excellent retention to nicotinic acid and isonicotinic acid, compounds structurally similar to the template. This dual recognition property of the polymer may be useful in circumstances where the preparation of a polymer for a specific template may be problematic because of poor stability or solubility.

[Esterification of octanoic acid with 1-octanol catalyzed by lipase in W/O microemulsions and in microemulsion-based organogels]

The esterification reactions of octanoic acid with 1-octanol catalyzed by Candida lypolytical (CL) lipase was studied in water-in-oil microemulsions formed by water/bis-(2-ethylhexyl)sulfosuccinate sodium (AOT)/isooctane. The results of kinetic study showed that the reaction follows a Ping-Pong Bi-Bi mechanism. The values of apparent kinetic parameters were determined. Lipase has also been immobilized in gelatin-containing AOT microemulsion-based organogels (MBGs) for retention of catalytic activity. These lipase-containing MBGs proved to be a solid-phase catalysts for use in apolar organic solvents, retaining its higher activity after many runs of esterification reactions.

Papain immobilization on a nitrilon fibre carrier containing primary amine groups

A carrier containing primary amine groups was synthesized by the reaction between nitrilon fibre and diethylenetriamine, and papain was immobilized on this kind of carrier by using glutaraldehyde as a coupling agent. The factors involved with the activity recovery of the immobilized papain and the enzymic properties of the resulting immobilized papain were studied in comparison with free papain, for which casein was chosen as a substrate. The results show that the activity recovery of immobilized papain can reach 47.3%, and that the immobilized papain exhibits better environmental adaptability and reusability than free papain.

[Study on preparation and pharmacodynamics of insulin-loaded polyester microparticles]

AIM

To investigate the possibility of using poly (epsilon-caprolactone-block-D, L-lactide) (PLCA) as a kind of materials to prepare the microparticles drug carrier.

METHODS

PCLA-MP (microparticle, MP) was prepared by double-emulsification solvent evaporation method. Its morphology was examined by scanning electron microscope. Its size diameter was examined by particle analyser. Insulin (INS), as a model drug, was then encapsulated into PCLA-MP (INS-PCLA-MP). HPLC method was established for determining INS in INS-PCLA-MP. An "antibody-capture" procedure was devised for investigating encapsulation mechanism. The in vitro release behaviour of INS-PCLA-MP was determined in phosphatic buffer solution (pH 7.4). The diabetic rat model was established and blood glucose levels were measured using glucose oxidase (GOD-PAP) method to evaluate the hypoglycaemic effects after subcutaneous administration of INS-PCLA-MP. The pharmacological bioavailability (PBA) of INS-PCLA-MP was calculated from the area above the curve (AAC) in contrast with INS-solution.

RESULTS

The mean diameter of INS-PCLA-MP was 1.9 microns, while the encapsulation ratio of INS reached to 76.46%. Only 18.25% encapsulated INS was on the surface of the microparticles, it could be measured by "antibody-capture" experiment. The in vitro release curve of INS-PCLA-MP consists of initial rapid release stage followed by slower exponential stage. In pharmacodynamic studies, after subcutaneous administration of INS-PCLA-MP 12 u.kg-1, the hypoglycaemic effect was significant. The PBA of INS-PCLA-MP was 123.08%.

CONCLUSION

PCLA might become a new drug carrier material in the future.

[Immunohistochemical study of the sinus mucosa during chronic maxillary sinusitis]

OBJECTIVE

To study the protective role of some immunocompetent cells and some humoral immune factors in the local mucosa during chronic sinusitis.

METHOD

Using immunohistochemical streptavidinbiotin peroxide complex (SABC) method to investigate the distribution and the numbers about the T-lymphocytes and subsets, B-cells, macrophages, NK cells, mast cells eosinophils, HLA-DR antigen and IgA, IgG, complement C3, lysozyme in the local mucosa of two type chronic sinusitis.

RESULT

The numbers of T-lymphocytes, T helper/inducer cells, B-cells and macrophages in the mucosa of chronic sinusitis type 1 was significantly more than these in the healthy control (P < 0.01). The number of T-lymphocytes, T suppressor cells, B cells, mast cells and eosinophils in the type 2 was significantly more than these in the healthy control (P < 0.01). The ratio of the helper cells to T suppressor cells significant different in the two type chronic sinusitis.

CONCLUSION

The study showed that the infiltrating of immunocompetent cells was different between the two type chronic sinusitis.

Synthesis, characterization, and antibacterial activity of novel Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes with vitamin K3-thiosemicarbazone

Vitamin K3-thiosemicarbazone (C12H11N3NaO4S2 x 5H2O, abbreviated as VT), a new Schiff base derivative, has been synthesized. Its crystal structure, determined by X-ray diffraction, is triclinic, space group P1. We have also prepared five novel complexes of VT with transition metals: [M(VT)(2)2H2O] x nH2O, (n = 1 and 2 for M = Cu(II) and Zn(II), respectively) and [M'(HVT)2Cl2] x mH2O, (m = 4, 5, and 7 for M' = Co(II), Mn(II), and Ni(II), respectively). These compounds were characterized by IR and UV-Vis spectroscopy, molar conductivity, thermal analyses, complexometric titration, and elemental analysis. In all the complexes, the VT ligand coordinates through sulfur and oxygen atoms, and the geometry around metal atom is best described as octahedral. In vitro tests of antibacterial activity showed that VT and its complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) all had strong inhibitory actions against G(+) Staphylococcus aureus, G(+) Hay bacillus, and G(-) Escherichia coli.

Effects of total parenteral nutrition on rat bile canaliculi: a stereologic analysis

OBJECTIVE

To quantitate, in a stereologic manner, changes in bile canalicular morphology before and after choleretic infusion of total parenteral nutrition (TPN) and to determine whether TPN produces changes in localized regions within the hepatic lobule.

STUDY DESIGN

Livers were obtained from sham-operated on normal adult male rats (control) and from rats that received intravenous TPN solution containing 20% glucose and 3.5% Molipron F. The tissues, obtained by a rigorous sampling procedure, were systematically subjected to stereologic analysis. Measurements were made on electron micrographs at two levels of magnification by point, intersection and profile counts, and then volume, surface area and length were estimated per unit parenchymal volume.

RESULTS

The surface area of the canalicular wall per parenchymal volume increased significantly (from 5.33 x 10(-2) to 6.73 x 10(-2) microns 2/micron 3) after TPN treatment, as did the length of microvilli (from 0.241 to 0.267 microns/micron 3). However, the volume of bile canalicular lumina per parenchymal volume (0.306% and 0.320%), total length of bile canaliculi (1.05 x 10(-2) and 1.06 x 10(-2) microns/micron 3) and diameter of microvilli (8.73 x 10(-2) and 8.94 x 10(-2) microns) remained constant.

CONCLUSION

These results indicate that changes in canalicular shape and microvillus hypertrophy may cause lowering efficiency of the bile flow rate.

Potent inhibition of tumor survival in vivo by beta-lapachone plus taxol: combining drugs imposes different artificial checkpoints

Ablation of tumor colonies was seen in a wide spectrum of human carcinoma cells in culture after treatment with the combination of beta-lapachone and taxol, two low molecular mass compounds. They synergistically induced death of cultured ovarian, breast, prostate, melanoma, lung, colon, and pancreatic cancer cells. This synergism is schedule dependent; namely, taxol must be added either simultaneously or after beta-lapachone. This combination therapy has unusually potent antitumor activity against human ovarian and prostate tumor prexenografted in mice. There is little host toxicity. Cells can commit to apoptosis at cell-cycle checkpoints, a mechanism that eliminates defective cells to ensure the integrity of the genome. We hypothesize that when cells are treated simultaneously with drugs activating more than one different cell-cycle checkpoint, the production of conflicting regulatory signaling molecules induces apoptosis in cancer cells. beta-Lapachone causes cell-cycle delays in late G(1) and S phase, and taxol arrests cells at G(2)/M. Cells treated with both drugs were delayed at multiple checkpoints before committing to apoptosis. Our findings suggest an avenue for developing anticancer therapy by exploiting apoptosis-prone "collisions" at cell-cycle checkpoints.

Self-Assembled Monolayer and Multilayer of Trichlorogermane Hexyl Propylate and Formation of GeO(2)/SiO(2) Interface

Monolayer and multilayer films of trichlorogermane hexyl propylate (Ge6) were formed by the self-assembly method on hydroxylated silicon substrates. The results showed that this kind of trichlorogermane had virtually the same self-assembly behavior as trichlorosilanes. Ellipsometry proved that the self-assembled monolayers and multilayers (SAMs) of Ge6 exhibited a tilted orientation to the substrate surface. The multilayer film of Ge6 on silicon substrate was obtained by reducing the monolayer SAMs to alcohol hydroxylated surface with LiAlH(4) and repeating the self-assembly process. The self-assembled multilayer film was calcined in air at 500 degrees C to form a thin layer of GeO(2) on SiO(2)/Si substrate surface. The XPS measurement detected the formation of GeO(2) layer. Copyright 1999 Academic Press.

Heat shock induction of a 65 kDa ATP-binding proteinase in rat C6 glioma cells

The 45, 55, 65 and 100 kDa ATP-binding proteinases (ATP-BPases) of the heat-shocked (44 degrees C for 30 min, recovery for 12 h) rat C6 glioma cells were purified by DEAE-ionexchange and ATP-affinity chromatography. Their molecular masses, isoelectric points (pI), pH-optima and other properties were analyzed by native proteinase gels. It was shown that the 65 kDa ATP-BPase is specifically induced by heat shock and not detectable in control cells. Its N-terminal 1-9 amino acid sequence was determined by Edman degradation, but no homologies to other proteins in the protein data bases were found. 30 and 31 kDa proteinases can be cleaved from the 45, 55 and 65 kDa proteinases to which they are linked. A possible relationship of the heat-induced 65 kDa ATP-BPase with the ATP-dependent proteinases (ATP-DPases) in prokaryotes and eukaryotes is discussed.

Release of mitochondrial cytochrome C in both apoptosis and necrosis induced by beta-lapachone in human carcinoma cells

BACKGROUND

There are two fundamental forms of cell death: apoptosis and necrosis. Molecular studies of cell death thus far favor a model in which apoptosis and necrosis share very few molecular regulators. It appears that apoptotic processes triggered by a variety of stimuli converge on the activation of a member of the caspase family, such as caspase 3, which leads to the execution of apoptosis. It has been suggested that blocking of caspase activation in an apoptotic process may divert cell death to a necrotic demise, suggesting that apoptosis and necrosis may share some upstream events. Activation of caspase is preceded by the release of mitochondrial cytochrome C.

MATERIALS AND METHODS

We first studied cell death induced by beta-lapachone by MTT and colony-formation assay. To determine whether the cell death induced by beta-lapachone occurs through necrosis or apoptosis, we used the PI staining procedure to determine the sub-G1 fraction and the Annexin-V staining for externalization of phophatidylserine. We next compared the release of mitochondrial cytochrome C in apoptosis and necrosis. Mitochondrial cytochrome C was determined by Western blot analysis. To investigate changes in mitochondria that resulted in cytochrome C release, the mitochondrial membrane potential (delta psi) was analyzed by the accumulation of rhodamine 123, a membrane-permeant cationic fluorescent dye. The activation of caspase in apoptosis and necrosis were measured by using a profluorescent substrate for caspase-like proteases, PhiPhiLuxG6D2.

RESULTS

beta-lapachone induced cell death in a spectrum of human carcinoma cells, including nonproliferating cells. It induced apoptosis in human ovary, colon, and lung cancer cells, and necrotic cell death in four human breast cancer cell lines. Mitochondrial cytochrome C release was found in both apoptosis and necrosis. This cytochrome C release occurred shortly after beta-lapachone treatment when cells were fully viable by trypan blue exclusion and MTT assay, suggesting that cytochrome C release is an early event in beta-lapachone induced apoptosis as well as necrosis. The mitochondrial cytochrome C release induced by beta-lapachone is associated with a decrease in mitochondrial transmembrane potential (delta psi). There was activation of caspase 3 in apoptotic cell death, but not in necrotic cell death. This lack of activation of CPP 32 in human breast cancer cells is consistent with the necrotic cell death induced by beta-lapachone as determined by absence of sub-G1 fraction, externalization of phosphatidylserine.

CONCLUSIONS

beta-lapachone induces either apoptotic or necrotic cell death in a variety of human carcinoma cells including ovary, colon, lung, prostate, and breast, suggesting a wide spectrum of anti-cancer activity in vitro. Both apoptotic and necrotic cell death induced by beta-lapachone are preceded by a rapid release of cytochrome C, followed by the activation of caspase 3 in apoptotic cell death but not in necrotic cell death. Our results suggest that beta-lapachone is a potential anti-cancer drug acting on the mitochondrial cytochrome C-caspase pathway, and that cytochrome C is involved in the early phase of necrosis.

Tat protein induces self-perpetuating permissivity for productive HIV-1 infection

We report that human immunodeficiency virus type 1 (HIV-1) has evolved a self-perpetuating mechanism to actively generate cells permissive for productive and cytopathic infection. Only activated T cells can be productively infected, which leads to their rapid depletion (2 x 10(9)/day in an infected individual). Establishment of productive HIV-1 infection therefore requires continual activations from the large pool of quiescent T cells. Tat protein, which is secreted by infected cells, activated uninfected quiescent T cells in vitro and in vivo. These Tat-activated uninfected cells became highly permissive for productive HIV-1 infection. Activation of primary T cells by Tat protein involved integrin receptors and was associated with activation of mitogen-activated protein kinases, including ERK1 and JNK kinase. Accordingly, these primary T cells progressed from G0 to the late G1 phase of the cell cycle.

The morphogenesis of a Chinese strain of HIV-1 forming inclusion bodies in Jurkat-tat III cells

A rapid/high replicative strain of human immunodeficiency virus type 1 (HIV-1) (BC9101) was isolated directly in the Jurkat-tat III cell line from a Chinese patient with AIDS. The thin-section electron microscopy was performed and revealed high efficiency of replication of BC9101 with some unusual biological properties. Many vacuoles, most of them filled with HIV particles, were found close to the nucleus. Double-cored virions and double budding were frequently observed in the vacuoles and at the vacuolar membrane. Virus particles matured by budding both into intracytoplasmic vacuoles and through the plasma membrane. Inclusion bodies of varying sizes, some consisting of thousands of HIV particles, were found in the cytoplasm. All the illustrated features describing formation of inclusion bodies were compatible with the observation that HIV particles were assembled at and budded from the cytoplasmic vacuole membrane. They were then released from the membrane into the vacuoles, and subsequently, the maturation occurred. Some of the vacuoles accumulated to such a high number of mature virus particles that inclusion bodies were formed. During the disintegration of the cells, the inclusion bodies surrounded by the vacuolar membrane were released from the cells. The nucleotide sequence of the vpu gene of BC9101 was investigated and indicated that the unusual biological properties may due to the lack of a start codon for translation of the vpu protein.

[Species-specific monoclonal antibodies against Chlamydia pneumoniae]

The purified elementary bodies (EBs) of C. pneumoniae ATCC VR1310 were used for primary immunization of male BALB/c mice (8 weeks of age), with the boost following on day 14. Spleen cells were fused with murine myeloma NS-1 cells on day 24 and hybrid cells were cloned by limiting dilution. Two clones, P17C2 & P33C, secreting species-specific monoclonal antibodies (MAbs) and immunoglobulin IgG2a class were obtained after elimination of those clones that produced antibodies against C. trachomatis L1, L2, A, B, C, E serovars, C. psittaci EAE strain and uninfected BGMK cell antigens. It was showed that the two clones of MAbs reacted with the MOMP 39.5 x 10(3) Da major outer membrane protein of all chlamydia species in Western blot and their ascites titers were more than 1:25 600 in Micro-IF test.

[Surgical treatment of obstructed superior vena cava]

From 1979 to 1989, 17 patients with obstructive superior vena cava resulted from different causes underwent various operations: azygos vein-right atrium bypass with an artificial vein (1 patient), external jugular vein-right atrium bypass (3 patients), innominate vein-right atrium bypass with the artificial veins made of autofascia (2 patients), and great saphenous veni-external jugular vein version (9 patients). Follow-up showed that version method is better than others because of good circulation and less thrombus formation.

Reduced neutrophil superoxide generation and plasma lipoperoxide levels in pigs fed with cod liver oil

Circulating neutrophils, isolated from pigs fed for 8 weeks with a diet supplemented with CLO, had an accentuated n-3 fatty acid incorporation into the plasma membrane, as evidenced by an approximately four-fold greater n-3/n-6 ratio as compared with the control diet group. Moreover, the neutrophils of the CLO fed pigs produced less superoxide when stimulated with PMA or f-MLP, as well as showing a more prolonged latency period before O2(-)-generation. In the plasma of pigs fed with CLO there were higher levels of thiobarbituric reactive material and lipofuscin, while the content of GSSG was similar in both dietary groups. The results of this study indicate that dietary supplementation with CLO reduces the activation of circulating neutrophils and favours the presence in the plasma of lipoperoxides.

Use of limited daily access to food in measuring the heat production associated with food intake in laying hens

1. Two experiments were carried out to determine the heat production associated with food intake in laying hens allowed access to food for one (experiment 2) or two hours (experiment 1) daily. 2. In experiment 1, heat production in the fed state was measured for two successive days after 46 h of food deprivation. The rate of heat production in the fasting state was measured from 47 to 69 h after feeding. 3. In experiment 2, heat production was measured at 4 fixed food intakes: 100, 70, 40 and 0 g/bird. Heat production associated with food intake, eating activity, net availability of ME and maintenance ME requirement was estimated. 4. Heat production after 46 h of food deprivation did not differ from that after 22 h of deprivation. In the hens receiving 100 g of food, heat production reached the pre-feeding level by 20 h after eating; the hens with lower food intakes reached the pre-feeding level more rapidly. It is suggested that the heat production associated with feeding had been eliminated by 22 h after eating. 5. Heat production associated with feeding was 16% of ME intake. Because the total energy cost of eating activity was only 0.8% of ME intake, the heat production associated with food intake in the limited-access hens came mainly from the effects of digestion, absorption and metabolism of the ingesta. 6. The net availability of ME was estimated to be 0.84. The estimated maintenance ME requirement was 569.6 kJ/kgW0.75 d.

Diurnal variation in heat production related to some physical activities in laying hens

1. Heat production, standing and eating activities, and hourly food intake of 4 laying hens were observed simultaneously and the effects of activity and food intake on heat production were studied. 2. Average heat production during the dark period (20.00 to 06.00 h) was 18.9 kJ/kgW0.75 h which was 33% lower than that during the light period. About 76% of the light-dark difference in the rate of heat production was probably associated with activity and posture. 3. Standing time, which included a range of behavioural activities, occupied 90% of the light period and the increased rate of heat production associated with standing was estimated to be about 18% of daily heat production. 4. Eating time occupied 40% of the light period; the heat production associated with eating activity represented about 5% of daily heat production or 3% of ME intake. 5. Because the regression of heat production on time spent eating agreed with the regression of heat production on hourly food intake, it is suggested that the energy expenditure associated with ad libitum feeding can be estimated for hens from the regression of heat production on hourly food intake.

[Wound infection after spinal surgery: analysis of 15 cases]

Fifteen of 714 patients undergoing spine surgery had postoperative wound infection, with an overall infection rate of 2.1%. There was infection rate of 0.4% in spine surgery without metal instrumentation and 2.9% in spine fusion with metal internal instrumentation. Coagulase positive staphylococcus aureus was the commonest pathogen. Factors related to infection were discussed and preventive measures were suggested. Irrigation-suction technique without removal of metal instruments and bone grafts was recommended for the treatment of postoperative infection. A high pseudarthrosis rate was found in the infected patients after spine fusion with metal instrumentation.

Order and Disorder in C 60 and K x C 60 Multilayers: Direct Imaging with Scanning Tunneling Microscopy

Monolayer and multilayer structures of C(60), a high temperature van der Waals solid, have been studied with scanning tunneling microscopy. Structures grown on GaAs(110) at 300 kelvin and at elevated temperatures show significantly different morphologies because of balances between thermodynamics and kinetics. Condensation onto stepped surfaces demonstrates preferred bonding and nucleation at step edges. Detailed studies of potassium incorporation in crystalline C(60) show highly ordered structures in the K(3)C(60) metallic state but disordered non-metallic structures for high potassium concentrations.

Ordered Overlayers of C60 on GaAs(110) Studied with Scanning Tunneling Microscopy

Studies of C(60) overlayer growth on GaAs(110) with scanning tunneling microscopy show large first monolayer islands that are locally well ordered, structurally stable, and commensurate with the GaAs surface owing to molecule-substrate interactions. Within the distorted close-packed structure, two distinct adsorption sites were identified, one of them being elevated because of stress in the C(60) monolayer.

[Intraosseous pressure measurement and bone marrow venography in idiopathic necrosis of femoral head]

Intraosseous pressure measurement and bone marrow venography were performed in 14 patients (25 hips) with idiopathic necrosis of femoral head. Increase of intraosseous baseline pressure was found in 95% of hips, positive stress test found in 91% of hips and venous stasis present in all cases. Core decompression could reduce intraosseous pressure and improve venous drainage. It was suggested that intraosseous hyperpressure and venous stasis play an important role in the pathogenesis of idiopathic necrosis of femoral head. The authors suggest that intraosseous pressure measurement and bone marrow venography are sensitive in revealing early stage changes of idiopathic femoral head necrosis.

[Diagnosis and treatment of idiopathic necrosis of the femoral head]

Fourteen cases, 25 hips, of idiopathic necrosis of femoral head (INFH) were included in our series. The role of radiographs, isotopic bone scanning, intraosseous pressure measurement and intraosseous venography in diagnosis of INFH was evaluated. Radiological examination cannot reveal early case, while isotopic bone scanning was more sensitive. There was increase of intraosseous pressure in most diseased hips. Intraosseous venography was abnormal in all examined hips. These two tests could therefore detect early INFH. Core decompression was performed on 21 hips. The operated hips were followed for 3.5 months to 20 months. Functional evaluation of 18 hips were good or excellent. Radiographic re-examination of 20 hips remained unchanged. The postoperative intraosseous pressure measurement and intraosseous venography in examined hips revealed a decrease of intraosseous pressure and improvement of venous drainage. Core decompression is therefore an ideal method of treatment for early INFH.

Studies on the phospholipid composition of pathogenic cell membranes of Mycoplasma hyopneumoniae

The membrane phospholipid and fatty acid compositions of Mycoplasma hyopneumoniae, a pathogen of porcine enzootic pneumoniae isolated in China, was studied by thin-layer chromatography and gas chromatography. The results showed that membrane phospholipids consisted predominantly of diphosphatidylglycerol. The percentage of C16 - C18 fatty acids comprised 79% of the total fatty acids, of which oleic acid as well as palmitic acid are the major fatty acids. Some differences were shown in fatty acid composition as compared with membranes of other species of Mycoplasma.