Myoglobin-containing carbon-paste enzyme microelectrodes for the biosensing of glucose under oxygen-deficit conditions

The response of first-generation glucose oxidase (GOx) amperometric glucose biosensors is strongly dependent on the concentration of the oxygen cosubstrate. The incorporation of the natural oxygen binder myoglobin into a GOx-containing carbon-paste matrix is shown to satisfy the oxygen demand of the enzymatic reaction and to provide convenient biosensing of glucose in oxygen-free solutions. Such use of myoglobin-containing mineral oil thus offers an attractive alternative to the use of oxygen-rich fluorocarbon pasting liquids. Further improvements are observed upon doping the fluorocarbon oil with myoglobin. Factors affecting the oxygen independence of the new enzyme microelectrodes, including the myoglobin loading or length of the oxygen reservoir, have been optimized. The myoglobin-doped mineral oil or Kel-F-based carbon-paste enzyme microelectrodes display a highly stable glucose response over prolonged (6-7 h) operations in oxygen-free solutions, indicating no depletion of the internal oxygen supply.

[Single-pump on-line addition of modifier for supercritical fluid chromatography]

Modified CO2 as mobile phase is usually necessary for packed-column supercritical fluid chromatography. Single syringe pump was applied in this work to add modifier through a parallel connection device, which can maintain constant and stable volume fraction of modifier without any contamination of the pump. Viscosity of the modifiers (here are methanol and acetone) and the length of the CO2 pipe line/modifier pipe line can affect the volume fraction. Volume fractions of methanol and acetone were determined by gas chromatography and ultraviolet spectrometry respectively and their rules of variation were also examined. It shows that the volume fraction of methanol is lower than that of acetone under similar condition. With fixed modifierr line, the longer the CO2 line is, the higher the volume fraction will be. The new device can conveniently alter the nature and ratio of the modifier with quite stable volume fraction. The online addition device can tentatively replace the dual-pump system.

[Vibration studies of amphetamine and methamphetamine by micro Raman]

For the first time, we obtained and investigated the Raman spectra of amphetamine and methamphetamine by micro Raman with incidence excitation light 514.5 nm under the ambient environment. According to the fact that both molecules belong to single substituted benzene which has the symmetry of Cy2v, the attribution of Raman vibration modes in amphetamine and methamphetamine molecules was carried out by studying the spectral lines in the two spectra. The Raman line that only appeared in methamphetamine but could not be seen in any other drugs we have investigated was most possibly attributed to the stretching vibration between C-N(+)-C.

Autoreactive IgG to intracellular proteins in sera of MS patients

IgG binding to multiple protein constituents in lysates of Jurkat cells was detected by Western blot in sera of patients with multiple sclerosis (MS) and systemic lupus erythematosus (SLE). The distribution patterns of bands with sera tested against protein lysates from normal Jurkat cells or from Jurkat cells exposed to apoptosis or oxidative stress inducing conditions were similar in most patients, but with inter-individual differences. The number of bands with sera of both patient populations far exceeded those (0 or 2 bands) detected with sera of healthy controls. Proteinase K, RNase and DNase pre-treatment of cell lysates suggested a protein nature for all of the antigens and a ribonucleoprotein (RNP) nature for some of the antigens recognized by serum IgG of MS and SLE patients. Only two MS patients had positive anti-nuclear antibody (ANA) titers, while all of them had positive Western blots. In addition to similarities, dissimilarities were also recognized between the humoral immune responses in MS and SLE. No IgG molecules were detected against phosphorylated proteins in the sera of MS patients, while multiple phosphoproteins were recognized by IgG molecules of SLE patients in immunoprecipitation experiments. These data suggest that in addition to ANA, the sera of MS patients contain autoantibodies directed against multiple intracellular proteins. The protein recognition patterns of immunoglobulins in MS share similarities, but also have distinct features when compared to those in SLE. The biological significance of these autoantibodies in MS remains to be understood.

Annealing behavior of barriers in ion-implanted LiNbO3 and LiTaO3 planar waveguides

We formed planar waveguides in LiNbO(3) and LiTaO(3) crystals by megaelectron volt He-ion implantation. The dark modes of both waveguides are measured and their refractive-index profiles are described according to the parameterized index profile reconstruction method. The extraordinary indices of both ion-implanted waveguides exhibit quite different profiles. We compare the thermal stability of barriers in ion-implanted LiNbO(3) and LiTaO(3) waveguides by annealing at different temperatures. The results show that the barrier in a LiTaO(3) planar waveguide has higher thermal stability than that in a LiNbO(3) waveguide. The experiments also show that annealing at a temperature higher than 400 degrees C results in recrystallization of the barrier.

A dominant-negative mutant of c-Jun inhibits cell cycle progression during the transition of CD4(-)CD8(-) to CD4(+)CD8(+) thymocytes

While Jun/Fos-containing transcription factors are known to be necessary for many TCR-mediated events in mature T cells, relatively little is known about their roles in thymocyte development. We have generated transgenic mice that express a trans-dominant-negative mutant of c-Jun (TAM-67) specifically in thymocytes. Expression of TAM-67 inhibited the up-regulation of AP-1-responsive genes such as c-jun and IL-2 in stimulated thymocytes from transgenic mice. In addition, altered thymocyte development in TAM-67-expressing mice was revealed by a decrease in thymic cellularity ( approximately 50%) which could be accounted for primarily by a reduction in the number of CD4(+)CD8(+) thymocytes, a large percentage of which retained CD25. The decrease in the number of CD4(+)CD8(+) thymocytes did not appear to be due to an enhanced rate of apoptosis but rather to a decrease in the number of CD4(-)CD8(-)CD25(-) cells in the S + G(2)/M stages of the cell cycle. These results indicate that Jun/Fos-containing transcription factors promote the proliferative burst that accompanies the transition from the CD4(-)CD8(-) to the CD4(+)CD8(+) stage of thymocyte development.

[Quality evaluation of locally-prepared kits for HIV antibody detection in clinical applications]

OBJECTIVE

To evaluate the quality of eight kinds of locally prepared enzyme-linked immunosorbent assay (ELISA) kits for HIV antibody (anti-HIV) detection and study their current status in clinical applications.

METHODS

Two hundred serum specimens were tested with eight kinds of locally prepared ELISA kits for anti-HIV screening, with an imported kit as reference, including 100 specimens with confirmed positive, negative or undetermined anti-HIV and 100 specimens collected from the drug abusers in Xinjiang Region.

RESULTS

Anti-HIV could be detected in all the 74 confirmed positive specimens with the imported reference kit, with sensitivity of 100%. But, six to eighteen specimens were false negative detected with local prepared kits, with sensitivities of 81.1%-91.9%, mainly in those collected from the drug abusers with weak positive for anti-HIV. Two of the 107 confirmed negative specimens were false positive by the imported reference kit, with a specificity of 98.2%, and 0-8 specimens were false positive by locally prepared kits, with specificities of 92.5%-100%.

CONCLUSION

The sensitivity of locally prepared ELISA kits for anti-HIV screening should be improved further to ensure the safety of blood transfusion and the control of AIDS/HIV.

Tracking RPE transplants labeled by retroviral gene transfer with green fluorescent protein

PURPOSE

To determine whether human retinal pigment epithelium (RPE) can be modified by retroviral-mediated gene transfer and to monitor the human RPE cells in the subretinal space of living rabbits with scanning laser ophthalmoscopy (SLO).

METHODS

Cultured human fetal retinal pigment epithelium (HFRPE) was exposed to green fluorescent protein (GFP)-transducing retroviral vectors, Moloney murine leukemia virus, and lentivirus. The cultured cells were followed by fluorescence microscopy. Suspensions of GFP-expressing HFRPE were transplanted into the subretinal space of pigmented rabbits, and the transplant sites were examined by SLO for fluorescence, including fluorescein and indocyanine green angiography. The rabbits were euthanatized at different times after transplantation, and the retinas were studied histologically.

RESULTS

Retroviral gene transfer can introduce a foreign gene such as GFP into cultured HFRPE. Gene expression is maintained in cultured RPE for at least 3 months. The lentiviral vector transduced both nondividing and dividing cells; the Moloney vector only transduced the latter. GFP-expressing cells can be followed in the living retina. Their changes reflect the rejection response followed histologically.

CONCLUSIONS

Cultured HFRPE could be transduced to express GFP for long periods of time by retroviral gene transfer. GFP allowed retinal transplants and gene expression to be monitored in vivo. These results provide a model for potential ex vivo gene therapy in the subretinal space.

Are lignins optically active?

The accepted derivation of lignins from non(enzymatically)-controlled radical coupling reactions has been recently challenged, and it is relevant to ascertain unequivocally whether lignins are or are not (as normally assumed) optically active. Two approaches were used. First, DFRC (derivatization followed by reductive cleavage) dimers derived from beta-5- and beta-beta-units in pine lignins, which certainly retain unaltered chiral centers (as well as beta-1- and beta-O-4-units where the intactness may be debated), were shown to be optically inactive by circular dichroism (CD) and chiral high-performance liquid chromatography. CD of beta-5-derived dimers following enantiomeric separation readily demonstrated the sensitivity of the method. Second, no optical activity could be detected (above 250 nm to avoid carbohydrate contributions) by CD of lignin isolates from pine, kenaf, maize, or a CAD-deficient pine mutant. Representative lignins are therefore not, within limits of detection by these methods, optically active.

Arylpropane-1,3-diols in lignins from normal and CAD-deficient pines

Significant quantities of arylopropane-1,3-diols have been identified in lignins isolated from a CAD-deficient pine mutant; smaller amounts are also present in lignins from normal pine. They arise from dihydroconiferyl alcohol via the action of peroxidases which are responsible for the radical generation steps of lignification. The structures in the complex lignin polymers are proven using 2D and 3D NMR of isolated lignin fractions.

[Mortality of primary liver cancer in China from 1990 through 1992]

OBJECTIVE

To study the geographical distribution and mortality of primary liver cancer (PLC) in China from 1990 through 1992.

METHODS

A death survey among one tenth of Chinese population was conducted in 1990-1992 and the data on PLC mortality were analyzed.

RESULTS

The crude mortality for PLC was 20.4 per 100,000 population (29.0 per 100,000 for males and 11.2 per 100,000 for females), accounted for 18.8% of the total cancer deaths in 1990-1992. In China, PLC mortality ranked second after stomach cancer. The age-standardized mortality rate (adjusted by the world population) of male Chinese was 33.7 per 100,000 which was 2. 2 times as high as that of male Japanese and 4.6 times as high as that of male Italian. The age-standardized rate of female Chinese was 12.3 per 100,000 which was 3.1 and 5.1 times as high compared to female Japanese and female Italian, respectively. PLC occurred in every age group but the mortality rate was highest in the age group of 30-44 years. The mortality was slightly higher in the rural than in the urban population. The cumulative death rate in the urban population was 3.5% for males and 1.2% for females, while that in the rural population was 4.1% for males and 1.6% for females. PLC showed geographical clustering along the south-east coast of China.

CONCLUSION

To prevent primary liver cancer remains to be the major task of cancer control in China.

Activation of gonadotropin-releasing hormone receptors produces neuronal excitation in the rat hippocampus

Whole-cell patch-clamp recordings of evoked action potentials were made in CA1 and CA3 pyramidal neurons of rat hippocampal slices. Previously we have demonstrated that activation of gonadotropin-releasing hormone (GnRH) receptors induces a long-lasting enhancement of synaptic transmission mediated by ionotropic glutamate receptors in CA1 pyramidal neurons of rat hippocampal slices. Here, we further studied whether activation of GnRH receptors could modulate intrinsic neuronal excitability in CA1 and CA3 pyramidal neurons of rat hippocampal slices. The use of a specific GnRH analog, leuprolide (10(-8) M), elicited a relatively long-term increase in evoked action potentials in CA1 and CA3 pyramidal neurons, respectively. The GnRH receptor-induced increase in evoked action potentials in both CA1 and CA3 pyramidal neurons could be abolished by a potent GnRH receptor antagonist, [acetyl-3,4-dehydro-Pro1,D-p-F-Phe2,D-Trp(3,6)]-LHRH (10(-8) M). The present study suggests that activation of GnRH receptors can lead to an increase of intrinsic neuronal excitability of both CA1 and CA3 pyramidal neurons in the rat hippocampus, an important integrative region for reproductive process, both endocrinologically and behaviorally.

Detection and determination of p-coumaroylated units in lignins

The derivatization followed by reductive cleavage (DFRC) method cleaves alpha- and beta-ethers in lignins but leaves lignin gamma-esters intact. When applied to grasses, which contain p-coumarate esters on their lignins, esterified monolignol derivatives are released. Saturation of the p-coumarate double bond occurs during DFRC, so the released products are 4-acetoxycinnamyl 4-acetoxyphenylpropionates. Synthesis of the esters allowed determination of response factors for the released products. Maize and bamboo lignins released 221 and 38 micromol/g of p-coumarate-derived esters. The sinapyl ester was much more abundant than the coniferyl one. The bamboo and maize lignin S/G ratios in the conjugates were 12 and 38 times greater than those of the normal monomers released by DFRC, evidence of a strong selectivity for acylation of syringyl units. Of three possible biochemical mechanisms for incorporating p-coumarates into lignin, evidence is mounting that the process involves incorporation of preacylated monolignols into the normal lignification process.

The DFRC method for lignin analysis. 7. Behavior of cinnamyl end groups

The behavior of cinnamyl end groups of lignins during the derivatization followed by reductive cleavage (DFRC) procedure has been investigated using lignin model compounds. On AcBr treatment, hydroxycinnamyl alcohols give rise mainly to 1-aryl-1, 3-dibromopropanes from which 1-aryl-3-bromopropanes and arylcyclopropanes are formed by zinc reduction. Arylpropene derivatives are also significant among DFRC products of etherified cinnamyl end-group models. Major monomers from DFRC of hydroxycinnamaldehydes are arylcyclopropyl acetates produced by reductive ring closure of 1-acetoxy-3-aryl-1,3-dibromopropanes. Although the reactions are not as clean as the ether-cleaving reactions that form the basis of the DFRC method, end groups produce diagnostic compounds that provide valuable markers for studying end groups in lignins.

[The changes of plasma endothelin-1 and calcitonin gene-related peptide levels in patients with pregnancy induced hypertension]

OBJECTIVE

To study the changes and clinical significance of plasma endothelin (ET-1) and calcitonin gene-related peptide (CGRP) levels in patients with pregnancy induced hypertension (PIH).

METHODS

Plasma ET-1 and CGRP were studied by immunoradiological method in 60 patients with pregnancy induced hypertension (PIH) and 23 normal pregnant women and 20 normal non-pregnant women.

RESULTS

The levels of plasma ET-1 in patients with PIH were significantly higher than those in healthy pregnancies (P < 0.01). There was a positive correlation between the plasma ET-1 level and degree of PIH; the higher the ET-1 level, the severer the PIH. The levels of plasma CGRP in patients with moderate and severe PIH decreased significantly than those in healthy pregnancy. There was a negative correlation between the plasma CGRP level and ET-1 level.

CONCLUSION

The results suggest that plasma ET-1 and CGRP concentration could be used as indicators for the severity of PIH. CGRP may be one of the antagonists of ET-1 in the pathogenesis of PIH.

[Right bundle branch block, ST segment elevation and sudden cardiac death. A clinical and electrocardiographic syndrome--Brugada syndrome]

The association of an abnormal electrocardiogram (ecg) consisting of right bundle branch block and ST segment elevation in leads V1-V3 and sudden arrhythmic death has been described in patients with no demonstrable structural heart disease. A patient with these ecg findings and aborted sudden death is presented. The patient had no structural heart disease and received an implantable cardioverter-defibrillator which seems to be the treatment of choice.

Activation of gonadotropin-releasing hormone receptors induces a long-term enhancement of excitatory postsynaptic currents mediated by ionotropic glutamate receptors in the rat hippocampus

Whole-cell patch-clamp recordings were made from CA1 pyramidal neurons of the rat hippocampus to study the modulation of gonadotropin-releasing hormone (GnRH) on synaptic transmission mediated by ionotropic glutamate receptors. Leuprolide (10(-9)-10(-7) M), a specific GnRH analog, concentration-dependently elicited a long-lasting potentiation of excitatory postsynaptic currents (EPSCs) mediated by ionotropic glutamate receptors. GnRH receptor-induced synaptic potentiation was blocked by 1 microM [Acetyl-3,4-dehydro-Pro1,D-p-F-Phe2,D-Trp3,6]-LHRH, a specific GnRH receptor antagonist. Furthermore, GnRH receptor-induced synaptic potentiation was associated with the stimulation of protein kinase C (PKC), being considerably attenuated by a potent PKC inhibitor (30 microM H-7). The results suggest a long-term enhanced modulation of GnRH on synaptic transmission mediated by ionotropic glutamate receptors, possibly via the actions of PKC in the hippocampus that is an important integrative system in the regulation of reproductive processes.

[Cellular immune response in mice vaccinated with uv-attenuated Toxoplasma gondii ZS1 strain trophozoites]

AIM

To explore the protective effect and cellular immune response of uv-attenuated ZS1 strain trophozoites of Toxoplasma gondii in mice.

METHODS

The ZS1 strain trophozoites of T. gondii were irradiated by uv-light with 2537 A wave length for 60 minutes. Mice were divided into 4 groups. Group 1 was vaccinated alone, group 2 was challenged with normal ZS1 trophozoites on d45 after vaccination, group 3 was infected alone, and group 4 was normal control. The changes in splenic T cell proliferation, level of CD4+ and CD8+ T cell, and NK cell activity were compared.

RESULTS

Group 1 mice survived normally, no trophozoite, pseudo-cyst or cyst was detected in the tissues on d49 after vaccination. Group 2 mice survived longer than those of group 3. The T lymphocyte proliferation in response to soluble antigen of T. gondii was significantly enhanced in group 2, and suppressed in group 3. The level of CD4+ T cell in group 2 was decreased, resulting in a reverse of CD4+/CD8+ ratio. The NK cell activities in groups 1, 2 and 3 were all significantly increased.

CONCLUSION

The uv-attenuated vaccine of T. gondii ZS1 strain could induce certain protective immunity against challenge infection, in which CD8+ T cell and NK cell might play an important role.

[Effects of humic acid on lipid peroxidation in arsenosis prevalent areas]

OBJECTIVE

To explore the causes of blackfoot disease in Taiwan.

METHODS

Experiments to induce lipid peroxidation by arsenic and humic acid were made in vitro. Arsenic was determined for the water sampled from the arsenosis prevalent areas in Inner Mongolia and blackfoot disease prevalent areas in Taiwan and humic acid determined for the extracts of the coal rich in arsenic sampled from Guizhou Province in China by MDA-TBA colorimetry.

RESULTS

Experiments found that humic acid could induce lipid peroxidation caused by sodium salt of unsaturated fatty acids in vitro in a weak and unstable manner, which could be promoted by 0.05 mmol/L of Fe(+ +) and not by 1 mmol/L As(2)O(3). The extent of lipid peroxidation caused depended on the sources, constituents and structure of humic acid samples, those from Inner Mongolia ranked the highest, those from Guizhou and Taiwan the medium and the commercial humic acid (Aldrich Co. in the US) the lowest. The experiments also found that lipid peroxidation caused by commercial humic acid presented a dynamic process in the existence of trace amount of iron, and humic acid could decompose the products of lipid peroxidation.

CONCLUSION

The experiments suggested the relations of humic acid and arsenic to iron and other transition elements in the blackfoot disease prevalent areas and areas with an environment rich in arsenic and humic acid.

Effect of Sinomenine on IL-8, IL-6, IL-2 produced by peripheral blood mononuclear cells

The effect of Sinomenine on IL-8, IL-6, IL-2 and mIL-2R produced by peripheral blood mononuclear cells was investigated by using cell culture, radioimmunoassay and flow cytometry. It was showed that production of IL-8 and mIL-2R was inhibited, but the levels of IL-6 were enhanced by Sinomenine. Our results also demonstrated that Sinomenine did not have any effect on the production of IL-2. The study demonstrated that Sinomenine was able to regulate the production of cytokines. This may be one of the mechanisms by which Sinomenine works on rheumatoid arthritis.

Religious and spiritual case reports on MEDLINE: a systematic analysis of records from 1980 to 1996

OBJECTIVE

To undertake a systematic analysis of case reports involving religious or spiritual issues published between 1980 and 1996.

DATA SOURCES

MEDLINE, the National Library of Medicine's bibliographic database covering the fields of medicine, nursing, dentistry, veterinary medicine, and the preclinical sciences.

STUDY SELECTION

A search of 4,306,906 records indexed on MEDLINE from 1980 to 1996.

DATA EXTRACTION

A total of 364 abstracts were found, then subjected to coding analysis.

DATA SYNTHESIS

Categories were developed for (1) types of healthcare situations involving religious/spiritual issues, (2) religious and spiritual interventions, (3) collaboration between healthcare and religious professionals, (4) psychopathology and sensitivity themes, and (5) religious faith/spiritual path. Although all of these case reports involved religious and spiritual issues, only 45 (12%) explicitly mentioned a religious professional. Of these, only 8 (2%) indicated any collaboration between healthcare and religious professionals.

CONCLUSIONS

A paucity of published case report literature exists on religious and spiritual issues (.008% of the MEDLINE records), indicating that the increasing acceptance of these factors by patients and healthcare professionals is not yet reflected in scientific and clinical journals. A need exists for more documented examples of collaboration between healthcare and religious professionals.

[Preparation of chitosan-gelatin mixed film and study on it's biodegradability]

A chitosan-gelatin film is prepared and the biodegradability and biocompatibility of the film are investigated by animal experiments. Results suggest that chitosan-gelatin film may be biodegraded faster and it has good biocompatibility. Lysozyme may promote biodegradation of the mixed film.

[ Measuring and assessing the quality of life of patients with pulmonary tuberculosis]

OBJECTIVE

To measure and assess the quality of life (QoL) of patients with pulmonary tuberculosis.

METHOD

QoL of 228 patients with pulmonary tuberculosis and 228 healty controls were marked by MOS SF-36, QLI and KPS scales, and single and multiple stepwise regression analysis were made to evaluate factors affecting QoL.

RESULT

The average total mark of SF-36, marks of physical functioning, role-physical, mental health, role-emotional, social functioning, vitality, bodily pain and general health were respectively 57 +/- 17, 65 +/- 28, 22 +/- 32, 61 +/- 20, 30 +/- 36, 54 +/- 27, 56 +/- 21, 65 +/- 24 and 53 +/- 15 in the pulmonary tuberculosis group, while 77 +/- 8, 84 +/- 23, 81 +/- 34, 75 +/- 18, 81 +/- 33, 83 +/- 23, 61 +/- 21, 75 +/- 24 and 72 +/- 20 in the controls. Statistically significant differences were found between the two groups (all P values < 0.01). The average marks of QLI and KPS were 7.4 +/- 2.0 and 77 +/- 17 respectively in the pulmonary tuberculosis group, and significant differences were also found comparing with the controls (9.6 +/- 0.8, 97 +/- 9) (P < 0.01). There were statistically significant correlation among the total mark of SF-36 and the marks of the above 8 subdividions in patients with pulmonary tuberculosis. The correlation coefficients between marks of SF-36 and QLI, KPS were 0.7841, 0.8931 respectively (P < 0.001). The factors affecting the marks of SF-36 of the patients were focus size of infection, counts of white blood cells, complications, elevated ALT and duration of disease.

CONCLUSION

The SF-36 scale is suitable for measurement of QoL of patients with pulmonary tuberculosis. The QoL of patients with pulmonary tuberculosis declines. The main factors affecting the QoL of the patients are focus size of infection, counts of white blood cells, complications, elevated ALT and duration of disease.