Effects of dietary inosinic acid on carcass characteristics, meat quality, and deposition of inosinic acid in broilers

An experiment was conducted to evaluate the effects of dietary inosinic acid (inosine 5'-monophosphate, IMP) on carcass characteristics, meat quality, and deposition of IMP in Arbor Acres broilers. A total of two hundred forty 1-d-old male Arbor Acres broilers were allocated to 4 inosinic acid treatments (0, 0.25, 0.50, and 0.75% dietary IMP supplementation). Birds were slaughtered at 42 d old. Dietary IMP did not significantly affect the carcass characteristics of broilers. No significant difference among treatments was observed in muscle pH within 1 h or at 24 h postmortem (PM), or in the decrease of muscle pH within 24 h PM. Inosinic acid had no marked effect on the color of breast muscle or Hunter L* and a* values of thigh muscle. Hunter b* values in thigh muscle were lower (P < 0.05) in the 0.75% IMP supplementation group than in the control group. Both breast and thigh muscle of birds fed with 0.25% IMP diet resulted in a lower (P < 0.05) shear force value compared with those fed with the other diets. All of the test groups had greater (P < 0.05) deposition of IMP in breast and thigh muscle than that of the control group with the exception of the 0.75% IMP supplementation group for thigh muscle. Greater (P < 0.05) corrected IMP value in breast muscle was detected for the test groups compared with the control group. These results suggest that extraneous IMP addition may contribute to the improvement of growth, meat quality, and deposition of IMP in broilers.

New class of plastic bulk metallic glass

An intrinsic plastic Cu(45)Zr(46)Al(7)Ti(2) bulk metallic glass (BMG) with high strength and superior compressive plastic strain of up to 32.5% was successfully fabricated by copper mold casting. The superior compressive plastic strain was attributed to a large amount of randomly distributed free volume induced by Ti minor alloying, which results in extensive shear band formation, branching, interaction and self-healing of minor cracks. The mechanism of plasticity presented here suggests that the creation of a large amount of free volume in BMGs by minor alloying or other methods might be a promising new way to enhance the plasticity of BMGs.

Genomic analysis of two porcine encephalomyocarditis virus strains isolated in China

Two strains of encephalomyocarditis virus (EMCV), designated BJC3 and HB1, were isolated from an aborted fetus and the heart tissue of a dead piglet that had pericardial fluid, respectively. The complete genomic sequences of the two viruses were determined and analyzed. The size of the genomes of BJC3 and HB1 were 7746 and 7735 nucleotides, respectively, including poly(A) tails. Comparative analysis with the genomic sequences of other EMCV strains showed that BJC3 and HB1 shared higher identity (92.5-99.6%) with BEL-2887A/91, EMCV-R and PV21, but lower identity (83.3-84.6%) with EMC-B, EMC-D and D variants, and only 81.0% with Mengo virus. Two amino acid mutations in the leader protein of the two viruses and one amino acid substitution in VP1 of BJC3 were found in comparison to other EMCV strains Phylogenetic analysis based on the amino acid sequences of the entire ORF revealed that the two Chinese isolates BJC3 and HB1 clustered together with the strains BEL-2887/91, EMCV-R and PV21, which belong to the same genetic subgroup as EMCV-30. Our results provide genomic information for EMCV isolated in China.

Clinical and pathologic changes in a guinea pig aerosol challenge model of acute Q fever

Acute Q fever is a zoonotic disease caused by the obligate intracellular bacterium Coxiella burnetii and can manifest as a flu-like illness, pneumonia, or hepatitis. A need exists in Q fever research for animal models mimicking both the typical route of infection (inhalation) and the clinical illness seen in human cases of Q fever. A guinea pig aerosol challenge model was developed using C. burnetii Nine Mile phase I (RSA 493), administered using a specialized chamber designed to deliver droplet nuclei directly to the alveolar spaces. Guinea pigs were given 10(1) to 10(6) organisms and evaluated for 28 days postinfection. Clinical signs included fever, weight loss, respiratory difficulty, and death, with the degree and duration of response corresponding to the dose of organism delivered. Histopathologic evaluation of the lungs of animals infected with a high dose showed coalescing panleukocytic bronchointerstitial pneumonia at 7 days postinfection that resolved to multifocal lymphohistiocytic interstitial pneumonia by 28 days. Guinea pigs receiving a killed whole-cell vaccine prior to challenge with the highest dose of C. burnetii were protected against lethal infection and did not develop fever. Clinical signs and pathological changes noted for these guinea pigs were comparable to those seen in human acute Q fever, making this an accurate and valuable animal model of human disease.

Prediction of early recurrence of atrial fibrillation after external cardioversion by means of P wave signal-averaged electrocardiogram

BACKGROUND

Therapy of atrial fibrillation by electrical cardioversion (CV) is limited by the high rate of recurrences. Early recurrence of atrial fibrillation (ERAF) occurs in a subgroup of patients whose characteristics are poorly defined. This prospective study was performed to evaluate if the P wave signal-averaged ECG (PSAECG) is able to identify patients with an increased risk of ERAF after CV.

METHODS

Patients with an indication for elective external CV were enrolled. After successful CV, PSAECGs were recorded at 0.5, 1, 24 h and 1 week. The ability of PSAECG parameters (signal-averaged P wave duration, PWD; root-mean-square of the voltage of the terminal 20, 30, and 40 ms of the signal-averaged P wave; RMS20, RMS30, RMS40) to predict ERAF (prospectively defined as AF recurrence within 4 h after CV) was assessed.

RESULTS

Of 111 consecutive patients, 7 experienced ERAF, 30 patients had AF recurrence later during the 1-week follow-up. Patients with ERAF had a significantly prolonged signal-averaged PWD compared to patients who remained in SR (194+/-16 ms vs 139+/-3 ms at 0.5 h, p<0.001). As ROC analysis revealed, a PWD >/=154 ms at 30 min after CV had the highest predictive accuracy for ERAF (sensitivity 100%, specificity 82%, positive predictive value 33%, negative predictive value 100%). Other parameters of the PSAECG did not reveal significant differences between patients with and without ERAF.

CONCLUSIONS

The PSAECG provides a sensitive noninvasive tool for detection of patients at risk of ERAF. Thus identified, tailored pharmacological therapy is conceivable to prevent ERAF.

Identification and cloning potentially protective antigens of Coxiella burnetii using sera from mice experimentally infected with Nine Mile phase I

Coxiella burnetii is an obligate intracellular bacterium that causes acute Q fever and occasional chronic infections in humans. To determine the immunodominant antigens during infection with C. burnetii, sera from mice experimentally infected with Nine Mile phase I were tested by immunoblotting. The mouse sera recognized antigens with a variety of molecular weights, including proteins of 14, 22, 28, 34, and 60 kDa as immunodominant antigens. In order to clone potential protective antigens, a genomic DNA library of Nine Mile phase I was constructed in the expression vector Lambda ZAP Express and screened with sera from mice that recovered from C. burnetii infection. A total of 102 immunoreactive clones with various signal intensities were identified from about 8,000 plaques. These clones were purified and expressed in the excised plasmid pBK-CMV. The proteins expressed by these recombinant plasmids were analyzed by SDS-PAGE and immunoblotting. Fifty-four clones expressed immunoreactive proteins of molecular masses ranging from approximately 14 to 60 kDa. Sequence analysis and BLAST search of the recently completed genome sequence identified a variety of novel immunoreactive proteins. These proteins are logical vaccine candidates for testing protective activity against C. burnetii challenge. We established a sublethal challenge model in BALB/c mice with protection from the development of severe splenomegaly as an indicator of vaccinogenic activity. Further characterization of these proteins will provide essential information for developing novel, specific diagnostic reagents and potential subunit vaccine candidates against C. burnetii infection.

Effect of tetramethyl pyrazine on L-type calcium channel in rat ventricular myocytes

To elucidate possible ionic mechanisms of antimyocardial ischemia and antiarrythmia of tetramethyl pyrazine (TP), we studied L-type Ca2+ currents (I(Ca.L)) in adult rat ventricular myocytes using the whole-cell patch-clamp technique. The results showed: (i) under physiological conditions, 0.25 mmol/L TP decreased amplitude of I(Ca.L) to 60.6% and this inhibition was increased with increasing concentration of TP. ID50 was 0.20 mmol/L. (ii) The Ca2+-antagonistic effect of TP was voltage-dependent. A marked negative shift of the steady-state inactivation curve was observed with long (10 s) conditioning prepulses, but not with short (350 ms) ones. (iii) The time course of inhibition during TP treatment was increased with an increase in drug concentration, and recovery from TP-induced inactivation of I(Ca.L) was slower than in control cases. (iv) Tonic block and use-dependent block with TP treatment, which was induced by increasing the frequency of stimulation, occurred. We suggest that TP inhibits the I(Ca.L) mainly by binding to inactivated Ca2+ channels. The high affinity of TP for the inactivated state of I(Ca.L) may play an important role in developing therapies for pathological conditions.

[Application of BRL conditioned medium in ES cells culture]

AIM

To study the method of using BRL conditioned medium in ES cells culture.

METHODS

ES cells were cultured in BRL conditioned medium, MEF feeder layer, and BRL conditioned medium plus MEF feeder layer respectively. Both the numbers of ES cells and embryonic bodies and the differentiated cells around the ES cell colonies at certain stages were studied to find the differences of growing speed of ES cells in three culture mediums.

RESULTS

On promoting the growth and maintaining the undifferentiated state of ES cells at the early stage after recovery, the effects of BRL conditioned medium were less than those of MEF feeder layer and those of BRL conditioned medium plus MEF feeder layer (P < 0.01), and there was no difference between MEF feeder layer and BRL conditioned medium plus MEF feeder layer (P > 0.05).

CONCLUSION

ES cells should be cultivated on MEF feeder layer or in BRL conditioned medium plus MEF feeder layer at the early stage after recovering.

[Separation and determination of pseudoephedrine in bufferin cold tablet by capillary electrophoresis with hydropropyl-beta-cyclodextrin as chiral selective reagent]

A method for the separation and analysis of the chiral pseudoephedrine enantiomers using capillary electrophoresis was established. The buffer solution for separation was 25 mmol/L Tris-phosphate, including 38 mmol/L hydropropyl-beta-cyclodextrin with pH value of 2.65. (1S, 2S)(+) Pseudoephedrine in Bufferin Cold tablet was determined. The method has good precision, recovery and linear relationship.

Groin hernias in adults: value of color Doppler sonography in their classification

PURPOSE

We assessed the abilities of color Doppler and power Doppler sonography to distinguish among types of groin hernias by demonstrating the inferior epigastric artery (IEA) and its relationship with the hernia sac.

METHODS

Nineteen consecutive patients (14 men and 5 women), clinically diagnosed as having groin hernias and scheduled to undergo herniorrhaphy, were prospectively enrolled in this study. Ultrasound examinations were performed preoperatively with a 6-12-MHz linear-array transducer. The IEA was identified, if possible, and its relationship to the hernia sac assessed. The sonographic diagnoses were compared with the operative findings.

RESULTS

There were 15 indirect inguinal hernias, 4 direct inguinal hernias, and 1 femoral hernia; 1 patient had bilateral inguinal hernias (indirect and direct). In 18 (90%) of 20 hernia cases, the trunk segment of the IEA could be visualized. In 11 (55%) of 20 hernia cases, the origin segment of the IEA could be visualized and its relationship with the hernia sac assessed. In 9 (82%) of the 11 hernia cases, hernia types were correctly diagnosed by sonography. The overall accuracy of sonography for diagnosing the type of hernia was 45% (9 of 20 hernias).

CONCLUSIONS

Color Doppler sonography can accurately differentiate types of groin hernias if the origin segment of the IEA and the hernia sac can be visualized simultaneously. However, color Doppler sonography sometimes failed to visualize this segment.

[Bepridil inhibition on the delayed rectifier K+ currents in thyroxine induced hypertrophied guinea pig ventricular myocytes]

AIM

To study the effects of bepridil on the rapidly activating component (IKr), the slowly activating component (IKs) of the delayed rectifier potassium current and the inward rectifier potassium current (IK1) in hypertrophied guinea pig ventricular myocytes.

METHODS

The whole cell patch clamp techniques were used.

RESULTS

In hypertrophied guinea pig ventricular myocytes, bepridil 30 mumol.L-1 markedly inhibited IKr and IKs (by 20.9% and 27.2% at 0 mV and mV, respectively). The effect of bepridil on IKs was larger than on IKr. Bepridil 30 mumol.L-1 also significantly inhibited the inward component of IK1 (by 15.1% at +100 mV), but the reverse potential of IK1 was unaffected. Bepridil (1-100 mumol.L-1) was shown to inhibit IKr and IKs in a concentration-dependent manner. Their IC50 were 46.7 mumol.L-1 and 23.8 mumol.L-1, respectively.

CONCLUSION

Bepridil inhibit IKr, IKs and IK1 in hypertrophied guinea pig ventricular myocytes, which may be important in understanding the antiarrhythmic effects of this drug.

[P-wave signal averaging-ECG: normal values and reproducibility]

Signal averaging techniques are used for detection of low amplitude, high frequency signals in the surface ECG. P-wave signal-averaging has been used to predict the risk for development of atrial tachyarrhythmias in patients with structural heart disease. There is, however, a lack of prospective studies evaluating normal values of the P-wave signal-averaged ECG in healthy individuals. Moreover, day-to-day reproducibility of results of P-wave signal-averaging is not precisely known. Thus, the aim of this study was to determine normal values and reproducibility of time-domain P-wave signal-averaging in a large cohort of healthy volunteers. A commercially available device (MAC 5000, Marquette Hellige) was used for signal-averaging. A vector magnitude was calculated from Frank's orthogonal leads after P-waves were sampled and filtered with a spectral filter using fast fourier transform. We examined 123 volunteers without cardiovascular disease at two occasions. Mean P-wave duration was 114 +/- 13 ms for the overall study population. There was a slight but statistically significant increase in filtered P-wave duration with age (r = 0.32, p < 0.001). All values were reliably reproducible upon the second examination (r = 0.624 to 0.706, p < 0.0001). These results may serve as a future reference to other studies examining patients with structural heart disease.

Puerarin blocks transient outward K+ current and delayed rectifier K+ current in mice hippocampal CA1 neurons

AIM

To study the effects of puerarin (Pue) on IA and IK in mouse hippocampal neurons.

METHODS

The whole cell patch clamp techniques were used.

RESULTS

Pue reduced the amplitude of IA and IK, in a concentration-dependent, but not rate- or use-dependent manner (IC50 were 461 micromol/L and 215 micromol/L, respectively). Pue (0.5 mmol/L) shifted the steady state activation curves of IA and IK to positive and negative potentials (Vh about 20.6 mV and 28.6 mV) respectively, but inactivation curves of IA were not affected by Pue.

CONCLUSION

Pue inhibited IA and IK in mouse hippocampal CA1 neurons and its blocking effect on I(K) was much stronger than on IA.

[Molecular mapping of the S-a locus for F1 pollen sterility in cultivated rice (Oryza sativa L.)]

F1 pollen sterility in cultivated rice (Oryza sativa L.) was found to be caused by at least six loci of F1 pollen sterility genes. At the S-a locus, one of the six loci for F1 pollen sterility, the allelic interaction of S-ai and S-aj causes the male gametes carrying S-aj allele abortive. To map the S-a locus, Taichung 65(T65), a Keng (japonica) variety with S-aj/S-aj, its isogenic F1 sterile line TISL4 with S-ai/S-ai from Chin-tsao, a Hsien (indica) variety, and the F2 population from cross T65 x TISL4 were used as materials. The polymorphism between T65 and TISL4 detected by RFLP and RAPD analysis was less than 1%. This result indicated that short segments from Chin-tsao were introgressed into the isogenic F1 sterile line, since the TISL4 was developed by repeatedly backcrossing for thirteen times. By linkage analysis of S-a and the marker loci, the S-a locus was mapped on chromosome 1. The genetic distances between S-a and RFLP markers CDO548 and RG146 are 6.4 cM and 7.2 cM respectively, and those between S-a and RAPD markers O11-1000 and Y13-500 are 6.8 cM and 11.2 cM respectively. The mapping of the S-a locus is an important step towards marker-aided selection for overcoming the hybrid sterility in rice.

Determination of berberine in Rhizoma coptidis and its preparations by non-aqueous capillary electrophoresis

A non-aqueous capillary electrophoretic method was established for the determination of berberine in Rhizoma coptidis and its preparations. The effects of organic solvent and the concentrations of sodium acetate were studied, which showed that berberine in extracts of traditional Chinese medicine can be separated successfully in a buffer solution of 75 mmol/L of sodium acetate in methanol containing 1 mol/L of acetic acid. The simple and rapid method was linear in the range 25-200 microgram/mL of berberine and had a good reproducibility, with the relative standard deviation below 2%. Non-aqueous capillary electrophoresis is a satisfactory system for the analysis of alkaloids in traditional Chinese medicine.

Chronic levothyroxin treatment is associated with ion channel abnormalities in cardiac and neuronal cells

1. We investigated the ion currents responsible for repolarization of guinea-pig isolated myocytes (ICa) and rat hippocampal CA1 neurons (IA and IK) by means of the whole-cell holding technique. 2. The rat hypertrophied heart, induced by levothyroxin, caused exaggerated cardiac arrhythmias after coronary ischaemia-reperfusion. 3. We found an enhanced ICa in guinea-pig isolated myocytes and decreased IA and IK in rat hippocampal CA1 neurons following levothyroxin treatment. Blockade of the outward K+ current and an increment in inward Ca2+ current by chronic levothyroxin treatment contributed to the delayed repolarization and aggravated cardiac arrhythmias. 4. Animals treated with chronic levothyroxin may serve as pathological models for the investigation of the pattern of ion channel disorders with regard to impaired repolarization and aggravated cardiac arrhythmias.

Determination of glycyrrhizin in radix glycyrrhizae and its preparations by capillary zone electrophoresis

A capillary zone electrophoresis method was set up for the separation and determination of glycyrrhizin in Chinese medicinal preparations. Concentrations of Na(2)B(4)O(7) were optimized, which showed that glycyrrhizin in the sample could be separated from interference in the running buffer of 30 mmol/L Na(2)B(4)O(7). Using declofenac as internal standard, the simple method was linear in the range 25-300 microg/mL of glycyrrhizin, and good reproducibility was obtained. The extracts of Radix glycyrrhizae and its preparations could be injected directly for analysis without any pretreatment.

Determination of tetrahydropalmatine in Chinese traditional medicine by nonaqueous capillary electrophoresis

Tetrahydropalmatine in Rhizoma corydalis and its preparations were separated and determined with no pretreatment in the buffer solution of 50 mmol/L of sodium acetate in methanol containing 2 mol/L acetic acid.

[Effects of doxepin on isolated basilar and saphenous artery rings of rabbits]

AIM

To study the effects of doxepin (Dox) on cerebral artery.

METHODS

The effects of Dox were observed using the isolated basilar and saphenous artery rings of rabbits.

RESULTS

Dox inhibited the constriction of the basilar and saphenous artery rings evoked by KCl with IC50 5.75 mumol.L-1 (95% confidence limits were 2.3-14 mumol.L-1, n = 8) and 34.6 mumol.L-1 (95% confidence limits were 3.8-316 mumol.L-1, n = 8), respectively. Dox also inhibited the constriction of the basilar and saphenous artery rings of the rabbits stimulated by 5-hydroxytryptamine (5-HT), IC50 were 6.3 mumol.L-1 (95% confidence limits were 1.7-23.3 mumol.L-1, n = 7) and 8.0 mumol.L-1 (95% confidence limits were 6.3-10.3 mumol.L-1, n = 6), respectively. In both samples (basilar and saphenous artery rings) CaCl2 evoked, the pD2 of Dox was 5.28 +/- 0.40 and 4.76 +/- 0.14, respectively (n = 6, P < 0.01). Dox 5.8 mumol.L-1 inhibited the constriction of the saphenous artery evoked by norepinephrine (NE) in Ca(2+)-free medium. Dox 30 mumol.L-1 inhibited the constriction of the saphenous artery evoked both by NE and by readmission of CaCl2 (1.25 mmol.L-1).

CONCLUSION

As compared with its effect on the saphenous artery, Dox selectively inhibited the basilar artery.

Evaluation of a recombinant 27-kDa outer membrane protein of Coxiella burnetii as an immunodiagnostic reagent

The 27-kDa outer membrane protein from eight strains of Coxiella burnetii was expressed in the pET-21c protein expression system. Two fusion proteins with molecular masses of 30 and 32 kDa were evident in all eight of the recombinants by SDS-PAGE and immunoblotting. A protein having an approximate size of 30 kDa was purified from the Escherichia coli lysates by one-step affinity purification. The utility of the purified recombinant protein in ELISA was also evaluated by testing its reactivity with human sera and comparing this reactivity with that of Nine Mile phase II antigen. All of the 40 IF-positive serum samples were ELISA-positive for both the Nine Mile phase II and recombinant antigens, and negative serum controls were negative for both antigens. These results suggest that ELISA with the 27-kDa recombinant antigen is a sensitive and specific method for detecting anti-C. burnetii antibodies in human sera.

Direct identification of Coxiella burnetii plasmids in human sera by nested PCR

Nested PCR assays were used for the direct identification of Coxiella burnetii plasmids in human sera. A total of 81 serum samples from 81 patients with Q fever were tested by nested PCR with four sets of primers. The first set of primers was used to detect the genomic sequences. The second set of primers was used to detect the conserved sequences of the plasmids. Another two sets of primers were used to identify the QpH1 and QpRS plasmids. QpH1 and QpRS plasmid-specific sequences were identified in 40 (49.4%) and 24 (29.6%) of the serum samples, respectively. Both of the QpH1 and QpRS plasmid-specific sequences were detected in 5 (8.6%) of the serum samples but were not found in 12 (20.7%) of the serum samples. Furthermore, all of the 23 acute-phase serum samples were positive for the QpH1 plasmid and negative for the QpRS plasmid. Nested PCR with plasmid-specific primers appears to be a useful method for the direct typing of C. burnetii plasmids in human sera.

Antigenic characteristics of polypeptides of Coxiella burnetii isolates

Eighteen Coxiella burnetii strains from a variety of clinical and geographical sources were screened for antigenic variation of polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with Coomassie brilliant blue (CBB) staining or immunoblotting. These polypeptide profiles showed the greatest variability in the region from 33 to 8.1 kDa. Such differences in the antigenicity of the polypeptides were also recognized by immunoblotting with 15 various mouse anti-C. burnetii antisera. In addition, we detected a polypeptide at about 28 kDa which was immunodominant in strains from human cases of acute Q fever, milk and ticks but not immunogenic in strains from human cases of chronic Q fever. These findings suggest that this polypeptide is a marker to distinguish between acute and chronic strains.

Inhibitory effects of nimodipine on platelet aggregation and thrombosis

AIM

To study the inhibitory effects of nimodipine (Nim) on rat platelet aggregation and arterial thrombosis in vivo.

METHODS

The aggregation rate of platelets induced by ADP and inhibition rate of Nim were measured by the change of light transmission. Effect of Nim on arterial occlusion time was measured by electric stimulation. Effect of Nim on the contents of 6-keto-PGF1 alpha and TXB2 in serum was measured by radioimmunoassay.

RESULTS

Nim 4.5, 9, 18, and 36 mg.kg-1.d-1 ig for 4 d restrained the platelet aggregation. The IC50 (95% confidence limits) was 26 (9-44) mg.kg-1. Nim 4.5, 9, and 18 mg.kg-1.d-1 ig for 4 d markedly prolonged the time of thrombotic occlusion in carotid artery induced by electric stimulation. Nim 9 and 18 mg.kg-1.d-1 improved the imbalance of 6-keto-PGF1 alpha/TXB2 in serum after thrombosis.

CONCLUSION

Nim was a potent inhibitor of platelet aggregation, which was partially concerned with the improved balance of 6-keto-PGF1 alpha/TXB2.

Differentiation of Coxiella burnetii by sequence analysis of the gene (com1) encoding a 27-kDa outer membrane protein

The gene (com1) encoding a 27-kDa outer membrane protein in 21 strains of Coxiella burnetii from a variety of clinical and geographical sources was sequenced for strain differentiation. The com1 gene was highly conserved among all the strains tested but there were several differences in nucleotide and deduced amino acid sequences. Based on the com1 gene-specific nucleotides and deduced amino acids, the 21 strains were divided into four groups. Group 1 contained 14 strains originating from ticks, cattle and human cases of acute Q fever. Groups 2 and 3 included 2 and 3 strains, respectively, originating from human cases of chronic Q fever. Group 4 contained 2 strains originating from a human case of acute Q fever and a goat with abortion. The results indicated that the strains originating from ticks, cattle and human cases of acute Q fever differed at the molecular level from those of human chronic Q fever. This study suggests that a sequence analysis of the com1 gene can be used for strain differentiation of C. burnetii.

Clinical evaluation of a new PCR assay for detection of Coxiella burnetii in human serum samples

A nested PCR method was developed for the detection of Coxiella burnetii in human serum samples. Two pairs of oligonucleotide primers were designed to amplify a 438-bp fragment of the com1 gene encoding a 27-kDa outer membrane protein of C. burnetii. The primers amplified the predicted fragments of 21 various strains of C. burnetii but did not react with DNA samples from other microorganisms. The 438-bp amplification products could be digested with restriction enzymes SspI and SalI. The utility of the nested PCR was evaluated by testing human serum samples. The com1 gene fragment was amplified from 135 (87%) of 155 indirect immunofluorescence test (IF)-positive serum samples and from 11 (11%) of 100 IF-negative serum samples. The nested PCR with primers targeted to the com1 gene appeared to be a sensitive, specific, and useful method for the detection of C. burnetii in serum samples.

Design and fabrication of a diffractive phase element for wavelength demultiplexing and spatial focusing simultaneously

The design of a diffractive phase element (DPE) that simultaneously implements wavelength demultiplexing and focusing is carried out on the basis of the general theory of amplitude-phase retrieval. The designed DPE is fabricated with optical contact lithography. Three masks are needed to produce the surface-relief structure of the DPE with eight quantized levels in depths. Experiments demonstrate that the designed DPE can successfully implement both the functions of demultiplexing three different-wavelength beams and focusing each component at a predesignated position simultaneously. Experimental measurements are in good agreement with the results of numerical simulations.

Rapid method for detection of Coxiella burnetii antibodies using high-density particle agglutination

A high-density particle agglutination test, using erythrocyte-sensitizing substance from phase II Coxiella burnetii adsorbed to high-density composite particles, was developed for rapid serodiagnosis of Q fever. The test was compared with the microimmunofluorescence test for sensitivity and specificity by using 3,036 human serum samples collected in Gifu Prefecture, Japan. An excellent agreement was found between the two tests for the acute-phase group and paired serum samples, but some discordant results were observed in the single-sample group. The sensitivity and specificity of the high-density particle agglutination test were both 100% in the former group and 81.6 and 99.9%, respectively, in the latter group. The test is a very promising tool for routine serodiagnosis of Q fever because of its simplicity, sensitivity, and specificity.

Q fever pneumonia in children in Japan

The prevalence of Q fever pneumonia among children with atypical pneumonia from whom only an acute-phase serum sample was available was traced by using an indirect immunofluorescence (IF) test, nested PCR, and isolation. Twenty (34.5%) of 58 sera were found to have both polyvalent and immunoglobulin M antibodies to the phase II antigen of Coxiella burnetii by the IF test. Q fever pneumonia was present in 23 (39.7%) of 58 patients as determined by both the nested PCR and isolation and in 20 patients as determined by the IF test. The sensitivities for nested PCR and isolation were 100%, and that for the IF test was 87%. Our results indicate that nested PCR was faster and more sensitive than isolation and the IF test in the diagnosis of acute Q fever when a single acute-phase serum was available. These findings suggest that C. burnetii is an important cause of atypical pneumonia in children in Japan.

Design of diffractive phase elements that produce focal annuli: a new method

A new optimization method based on the general theory of amplitude-phase retrieval is proposed for designing the diffractive phase elements (DPE's) that produce focal annular patterns. A set of equations for determining the phase distribution of the DPE is given. The profile of a surface-relief DPE can be designed with an iterative algorithm. Numerical calculations are carried out for several examples. A comparison of the performance of the DPE's designed with the Gerchberg-Saxton algorithm and the new algorithm is presented. The effect of quantization of the phase distribution of the DPE's on the results is also investigated. The results show that the new algorithm can successfully achieve the design of the DPE's that convert the uniform incident beam into the focal annular patterns.

Isolation of Coxiella burnetii from dairy cattle and ticks, and some characteristics of the isolates in Japan

Coxiella burnetii was isolated from raw milk (36/214, 16.8%) and uterus swab samples (13/61, 21.3%) originating from dairy cattle with reproductive disorders, aborted bovine fetus samples (2/4, 50%), mammary gland samples (4/50, 8%) originating from healthy dairy cattle, and tick samples (4/15, 26.7%) originating from 2 pastures. Fifty-nine strains had various degrees of pathogenicity, high (8; 13.6%), moderate (28; 47.5%) and low (23; 39%), for guinea pigs. The results of isolation suggested a high prevalence of Coxiella infection in dairy cattle with reproductive problems in Japan. Twelve strains (7, 2 and 3 strains from cattle, ticks and humans, respectively) and the reference Nine Mile strain of phases I and II were propagated in both yolk sacs of embryonated hen eggs and Buffalo green monkey (BGM) cell cultures. Protein profiles of these strains were similar to those of the reference strain of phase I. Lipopolysaccharide (LPS) profiles of 12 strains were similar to those of the reference strain of phase I and different from those of the reference strain of phase II. The LPS profiles of 12 strains suggested that these strains are associated with an acute form of Q fever.

[Seroepidemiological study of HBV and HCV infection in sexually promiscuous groups]

A serological study on the detection of HBV and HCV infection markers and the investigation of related sexual behaviors were conducted among 431 female prostitutes and 109 normal women. The result showed of anti-HBc prevalence rate was 43.1% (186/431), anti-HBs positive rate was 36.9% (159/431), HBsAg positive rate was 11.1% (48/431) and anti-HCV positive rate 9.51% (41/431). They were all significantly higher in prostitutes than in normal women. The infection indexes of HBV and HCV were also higher in population with STD than in normal women. The prevalence of anti-HCV in female prostitutes tended to increase with increase of age. There was a significant correlation with the number of their clients and years of being prostitutes. This demonstrated that there was a relatively high HBV and HCV infection rates in prostitutes.

[Effects of high-level-manganese sewage irrigation on children's neurobehavior]

The neurobehavioral status was tested for 92 matched-pair pupils aged 11-13 in an area with high-level-manganese sewage irrigation and a control area. Results showed there was significant difference in manganese contents of drinking water between the area with sewage irrigation and the control area during 1990-1992, ranged 0.241-0.346 mg/L and 0.030-0.040 mg/L, respectively, with P < 0.01. Hair manganese content of children in the area with sewage irrigation (1.252 micrograms/g) was significantly higher than that in the control area (0.961 micrograms/g) with P < 0.01. Scores in digit span, Santa Ana manual dexterity, digit symbol, Benton visual retention test and pursuit aiming test for children in the area with sewage irrigation were significantly lower than those in the control area (P < 0.01). Hair manganese contents of the children in the area with sewage irrigation correlated negatively with most of those scores. It suggested high level of manganese in drinking water of the area with sewage irrigation might be an important factor affecting children's neurobehavioral changes.

[Is there hepatitis C virus associated glomerulonephritis?]

Hepatitis C virus (HCV) infection is one of the important causes of chronic and severe hepatitis in China. In an attempt to understand if there is any relationship between HCV infection and glomerulonephritis (GN), serum samples from 570 GN patients and 100 normal volunteers were screened for anti-HCV antibody (HCV-Ab) with ELISA method. Among the cases with positive HCV-Ab, serum HCV-RNA was tested with nested RT-PCR method. The incidence of serum HCV-Ab was 2 in 100 normal volunteers (2%) and 34 in 570 GN patients (6%). The incidence of positive serum HCV-RNA was 0 in normal volunteers whereas 21 in GN patients. The main clinical manifestation of GN patients with serum positive HCV-Ab was an unique proteinuria with/without nephrotic syndrome or renal failure, whereas the pathologic lesions in GN patients with serum positive HCV-Ab or HCV-RNA consisted of different disease entities. There was no close link between MPGN and active HCV infection. From the data observed, it seems that there is a coincidence between glomerular diseases and HCV infection rather than a matter of cause and consequence.

[Sequencing of hepatitis B virus DNA fragment coding major HBsAg of escape mutant]

We amplificated a HBV DNA fragment coding the major HBsAg from a chronic HBsAg carrier's serum with high titer of HBsAg and anti-HBs using polymerase chain reaction (PCR). The direct sequencing of PCR products revealed a single mutation from adnosine to guanosine at the nucleotide position 532 of HBV DNA of the escape mutant. This mutation might result in an amino acid substitution from threonine to alanime at the amino acid position 126 of HBsAg. Since this amino acid is located in the first loop of the "a" determinant of HBsAg, the mutation might result in an alteration of the structural antigenicity of the "a" determinant and induce escape mutant of HBV.

Tissue and serum levels of steroid hormones and RU 486 after administration of mifepristone

The present study was designed to examine the effect RU 486 administration on steroid hormone levels in serum and decidua. Sixty women at 6-7 weeks gestation were divided into three groups. The first group took a placebo 24 hours before interruption of pregnancy. The other two groups took 200 mg mifepristone 12 and 24 hours before the surgical procedure, respectively. The concentrations of steroids and mifepristone were measured by radioimmunoassay or high performance liquid chromatography. Mifepristone treatment increased the levels of estradiol, cortisol and testosterone in serum and decidual cytosol (p < 0.05 or p < 0.01). A minor elevation in progesterone level was observed but was not statistically significant. The tissue levels of progesterone, estradiol and testosterone were much higher than the serum levels, whereas RU 486 concentration in the tissue was only one-third of the serum level. In addition, the RU 486 level in decidual cytosol was of the same order as that of progesterone. This competitive concentration was not achieved in chorionic villi in our previous observation, explaining why mifepristone exerts its predominant effect on decidua rather than villi. It is concluded that RU 486 reached an effective inhibitory concentration in decidua and had significant effects on the endocrine milieu.

Pharmacokinetic study of RU 486 and its metabolites after oral administration of single doses to pregnant and non-pregnant women

RU 486 and three of its metabolites (RU 42633-monodemethyl, RU 42848-didemethyl, and RU 42698-hydroxymetabolite) were determined by HPLC in plasma from nine non-pregnant and 36 pregnant women. Each non-pregnant subject took an oral dose of RU 486 (25, 100, 400 and 600 mg consecutively) once per menstrual cycle. Six of the nine women also received a dose of 200 mg. The 36 pregnant women were randomized into four groups which were given a single dose of 25, 100, 400 or 600 mg RU 486. Blood samples were taken up to 120 h after dosing. Peak concentrations of RU 486 occurred on most occasions within 2 h. Plasma concentrations at 1 h and at 24 h increased in proportion to log dose. There was a wide variability (up to ten-fold) in the pharmacokinetic parameters within each dose group. Plasma concentrations of RU 42633 were similar to those of RU 486 but concentrations of RU 42848 and RU 42698 were much lower. As with RU 486, the plasma concentrations of the metabolites were maintained at high levels for up to 48-72 h after dosing. The findings were consistent with a rapid metabolism of RU 486 to RU 42633; removal of the second methyl group leading to RU 42698 occurred much more slowly and to a much less extent than removal of the first. There appeared to be no significant differences between the non-pregnant and pregnant women in either the plasma concentrations or pharmacokinetic parameters of RU 486 and its metabolites.

[A preliminary report on the prevalence of different types of hepatitis in adult patients with acute sporadic hepatitis in Beijing area]

In order to investigate the prevalence of different types of viral hepatitis in Beijing area, the markers of viral hepatitis A, B, C and E were detected on 72 adult patients with acute viral hepatitis in the infectious diseases department of our hospital. The results showed that 26.4% of the cases had HAV infection, 8.3% HBV infection, 18.1% HCV infection and 31.9% HEV infection. It is shown that the prevalence of HEV infection in Beijing area is high.

[Effects of tetramethylpyrazine on rabbit basilar artery ring and canine vertebroarterial circulation]

Tetramethylpyrazine (TMP) inhibited the contraction of rabbit basilar artery and mesenteric arteries caused by KCl with an IC50 of 1.3 mmol.L-1 and 7.5 mmol.L-1 (P < 0.01). The contraction of the rabbit basilar and mesenteric artery ring evoked by KCl, CaCl2 and norepinephrine was inhibited noncompetitively by TMP with the pD2' values of 2.18 +/- 0.16 and 1.83 +/- 0.18 (P < 0.01), 2.13 +/- 0.12 and 2.08 +/- 0.12 (P > 0.05), 3.08 +/- 0.16 and 2.57 +/- 0.08 (P < 0.01), respectively. The contraction of rabbit basilar artery and saphenous veins evoked by 5-HT was also inhibited by TMP with an IC50 of 0.22 mmol.L-1 and 2.2 mmol.L-1 (P < 0.01), respectively. TMP antagonized the myogenic activity of rat portal vein strips. TMP increased canine vertebroarterial blood flow and had no effect on femoral artery blood pressure. The results suggested that TMP may block the calcium channel, inhibit the contraction of rabbit basilar artery, and improve the canine vertebroarterial circulation selectively.

[Effects of imipramine on isolated rabbit basilar artery]

Imipramine (Imi) inhibited the contractile response to BAY k 8644 (IC50 = 2.39 +/- 0.33 mumol.L-1), KCl (IC50 = 1.00 +/- 0.09 mumol.L-1), in rabbit basilar artery rings. Imi was more effective in suppressing the contractile response evoked by KCl, CaCl2, and 5-HT in basilar artery rings than in mesenteric artery rings. The effect of Imi was the same as that of diltiazem (Dil). There was no difference between the inhibitory response of Imi on contraction induced by KCl in basilar artery rings with or without endothelium. The results suggest that Imi may block the calcium channel and inhibit the rabbit basilar artery selectively, and the effect is endothelium-independent.

[Effects of trihexyphenidyl on slow action potentials in guinea pig papillary muscles]

Effects of trihexyphenidyl (THP) were examined on the slow action potentials (SAP) induced by isoproterenol (Iso), histamine (His), Bay k 8644 or tetrodotoxin (TTX), in guinea pig papillary muscles. THP 10, 50, and 100 mumol.L-1 depressed the maximal upstroke velocity (Vmax) and the action potential amplitude (APA) of SAP. These effects were reversed partially by the elevation of the concentration of calcium from 2.0 to 5.6 mmol.L-1. The results suggest that THP can inhibit calcium inflow in myocardium.

Location of myocardial infarction and its surface cardioelectric representation. An experimental study

In order to explore the relationship between the different location of myocardial infarction (MI) and reflections of pathognomonic Q potentials on the body surface, an experimental study was carried out in 28 dogs. The results were (1) in 27 of a total 28 dogs after MI formation, abnormal Q maps appeared; (2) right ventricular MI, posterior wall MI and some lateral and apical MI are prone to miss abnormal Q potentials in the conventional 12-lead ECG; and (3) the MI location and relative size diagnosed through electrocardiographic peak mapping (EPM) correlated to acute MI in dog ventricles fairly well. The unexpected Q map reflections of right ventricular MI provide new clues for improving our automatic diagnosis system after further correlative studies. The results strongly support the feasibility of the application of EPM in clinical diagnosis.

High-performance liquid chromatographic determination of peptides released by tryptic degradation from opioid peptide precursors in rat brain

A high-performance liquid chromatographic method involving postcolumn fluorescence derivatization is described for the quantification of five fragment peptides (methionine-enkephalin-Thr-Ser-Glu-Lys, methionine-enkephalin-Lys, methionine-enkephalin-Arg, leucine-enkephalin-Lys and leucine-enkephalin-Arg) released by tryptic digestion from the opioid peptide precursors (proopiomeranocortin and proenkephalins A and B) in rat brain tissues. The tissue proteins containing the precursors are hydrolyzed with trypsin to the fragment peptides. The peptides are separated on an Asahipak ODP-50 column and on-line detected fluorometrically by using hydroxylamine, cobalt(II) and borate buffer reagents. The detection limits (S/N = 3) for the peptides are 0.7-2.8 pmol per 100 microliters injected. The distribution of the precursors in the brain tissues was also discussed on the basis of the determined values of the fragment peptides.

Pre-column fluorescence derivatization high-performance liquid chromatography of opioid peptides in rat brain and its use for enzymatic peptide characterization

A high-performance liquid chromatographic method involving fluorescence derivatization followed by separation on a reversed-phase polymer (octadecylated polyvinylalcohol copolymer gel) column is described for the determination of opioid peptides in rat brain tissues. The peptides extracted from brain tissues were converted into fluorescent derivatives by reaction with hydroxylamine, cobalt(II) ion and borate. The derivatives were separated on an Asahipak ODP-50 column by gradient elution of acetonitrile in the mobile phase containing borate buffer (pH 9.5). The detection limits (S/N = 3) for the peptides were 0.33-1.21 pmol per 100 microliters injected. The method actually permit the determination of leucine enkephalin, methionine enkephalin, methionine enkephalin-Arg-Phe and methionine enkephalin-Arg-Gly-Leu in the tissues. The method is also applied to the characterization of the peptides in the tissues by means of enzymatic degradations with carboxypeptidase A and trypsin.

[Effects of trihexyphenidyl on basilar artery of rabbits and cerebrovascular circulation of rats]

Trihexyphenidyl (Tri) inhibited the contraction of rabbit basilar artery due to high K+ (45.6 mmol/L). IC50 was 2.9 +/- 0.7 mumol/L. The contractions of basilar and mesenteric arteries due to calcium and those of basilar artery and saphenous vein due to serotonin were noncompetitively. Tri inhibited myogenic activities of the portal vein strips of rats and increased the normal cerebral blood flow of rats to 19 +/- 7 ml/(min.100 g).

An experimental animal model of Kashin-Beck disease

Twelve young macaque monkeys were fed with grain and water from areas actively endemic or non-endemic for Kashin-Beck disease. Both dietary grain and water from geographical areas endemic for Kashin-Beck disease induced a sequence of pathological changes in the growth plates and articular cartilage and biochemical changes in the serum and urine of monkeys. These changes are similar to those in human Kashin-Beck disease. It is considered that this may be a simple and valuable model for the further study of this disease and its management and control. The results suggest that the pathogenetic factors of Kashin-Beck disease relate both to grain and to water in the diet in endemic areas. The experiment also shows that certain serum enzyme concentrations correlate with chondronecrosis.