Distribution characteristics of the Legionella CRISPR-Cas system and its regulatory mechanism underpinning phenotypic function

Legionella is a common intracellular parasitic bacterium that infects humans via the respiratory tract, causing Legionnaires' disease, with fever and pneumonia as the main symptoms. The emergence of highly virulent and azithromycin-resistant Legionella pneumophila is a major challenge in clinical anti-infective therapy. The CRISPR-Cas acquired immune system provides immune defense against foreign nucleic acids and regulates strain biological functions. However, the distribution of the CRISPR-Cas system in Legionella and how it regulates gene expression in L. pneumophila remain unclear. Herein, we assessed 915 Legionella whole-genome sequences to determine the distribution characteristics of the CRISPR-Cas system and constructed gene deletion mutants to explore the regulation of the system based on growth ability in vitro, antibiotic sensitivity, and intracellular proliferation of L. pneumophila. The CRISPR-Cas system in Legionella was predominantly Type II-B and was mainly concentrated in the genome of L. pneumophila ST1 strains. The Type II-B CRISPR-Cas system showed no effect on the strain's growth ability in vitro but significantly reduced resistance to azithromycin and decreased proliferation ability due to regulation of the lpeAB efflux pump and the Dot/Icm type IV secretion system. Thus, the Type II-B CRISPR-Cas system plays a crucial role in regulating the virulence of L. pneumophila. This expands our understanding of drug resistance and pathogenicity in Legionella, provides a scientific basis for the prevention of Legionnaires' disease outbreaks and the rational use of clinical drugs, and facilitates effective treatment of Legionnaires' disease.

[Simultaneous detection of 7 important Rickettsiales pathogens by TaqMan-probe quantitative real-time PCR]

Objective: To establish and optimize a TaqMan-probe quantitative real-time PCR (qPCR) assay for the detection of 7 important Rickettsiales pathogens and simultaneous identification of the infection types. Methods: Based on the ompB gene of Rickettsia prowazekii, Rickettsia mooseri and spotted fever group rickettsiae, the groEL gene of Orientia tsutsugamushi, the 16S rRNA of Ehrlichia chaffeensis, the gltA gene of Anaplasma phagocytophilum and the com1 gene of Coxiella burnetii, we synthesized primers and TaqMan-probes and optimized the reaction system and reaction process to same solution. The sensitivity, specificity and reproducibility of this assay were evaluated and the assay was used for the detection of simulated and actual samples. Results: The Ct value of the standard curves of the 7 pathogens showed a good linear relationship with the number of DNA copies (all R² >0.990 0), the minimum detection limit was 10 copies/μl, showing good specificity. In the 96 tick nucleic acid extracts, Coxiella burnetii was detected in 1 sampleand spotted fever group Rickettsiae was detected in 3 samples. In the 80 blood samples from patients with undefined febrile illness, Orientia tsutsugamushi was detected in 1 sample and spotted fever group rickettsiae was detected in 2 samples. Conclusions: In this study, based on the established TaqMan-probe qPCR assay, the reaction system and reaction condition of the 7 important pathogens of Rickettsiales were optimized to the same solution. This method overcomes the shortcomings of using different reaction systems and reaction conditions for different pathogens, which can precisely identify the species of 7 important pathogens of Rickettsiales in clinical sample detections and is important for the infection type identification and laboratory detection time reduction to facilitate precise treatment of the patients.

Emergence of ehrlichiosis by a new tick-borne Ehrlichia species in China

OBJECTIVES

From March to June 2021, the reported number of clinically diagnosed endemic typhus in Anhui and Hubei provinces of China nearly increased four-fold compared with the monthly average numbers in last 5 years. An etiological and epidemiological investigation was initiated.

METHODS

The clinical specimens from the reported patients and the potential vector ticks were collected for molecular and serological detection, as well as cell culturing assay to identify the potential pathogen.

RESULTS

Polymerase chain reaction and sequence analysis of rrs and groEL showed that the pathogen from these patients was Ehrlichia sp., isolated from Haemaphysalis longicornis attached to these patients. The phylogenetic analysis based on 39 Ehrlichia genomes suggested that it should be taxonomically classified as a novel species, tentatively named "Candidatus Ehrlichia erythraense". A total of 19 of 106 cases were confirmed as Candidatus Ehrlichia erythraense infections by polymerase chain reaction, sequencing, and/or serological tests. The most frequent symptoms were fever (100%), rashes (100%), asthenia (100%), anorexia (100%), and myalgia (79%).

CONCLUSION

The occurrence of the disease presenting with fever and rashes in Anhui and Hubei provinces was caused by a novel species of the genus Ehrlichia; physicians need to be aware of this newly-discovered pathogen to ensure appropriate testing, treatment, and regional surveillance.

Inverse association between bone mineral density and fibrinogen in menopausal women

OBJECTIVE

Inflammatory diseases are risk factors for osteoporosis. We aimed to explore whether fibrinogen, which is linked to chronic inflammation, is associated with bone mineral density (BMD) in menopausal women.

METHODS

In this cross-sectional study, we analyzed 339 menopausal women from Zhejiang Province between January 2016 and October 2019. Linear regression analysis was performed to assess the relationship between fibrinogen and BMD.

RESULTS

Significant inverse association was observed between the serum fibrinogen level and BMD in menopausal women. The mean BMD in each quartile of fibrinogen level was 0.901, 0.897, 0.892, and 0.855 g/cm², respectively (p = 0.027). After adjusting for age, body mass index, metabolic profiles, blood inflammatory factors, and serum levels of estradiol, calcium, phosphorus, and alkaline phosphatase, fibrinogen levels remained significantly associated with BMD (regression coefficients for quartiles 1-3 vs. quartile 4 were 0.046, 0.027, and 0.036, respectively; p for trend <0.05).

CONCLUSIONS

Higher fibrinogen levels were associated with lower BMD in menopausal women, which was independent of age, body mass index, estradiol, and other factors. Therefore, serum fibrinogen can be used as a new predictor of reduced BMD in menopausal women.

[Prognostic value of N-terminal B-type natriuretic peptide on all-cause mortality in heart failure patients with preserved ejection fraction]

Objective: To investigate the prognostic value of N-terminal B-type natriuretic peptide (NT-proBNP) on all-cause mortality in heart failure patients with preserved ejection fraction (HFpEF) at real world scenarios. Methods: Patients who met the diagnostic criteria of HFpEF in the China National Heart Failure Registration Study (CN-HF) were divided into death and survival groups. The demographic data, physical examination, results of the first echocardiography, laboratory results at admission, complications, drug use and clinical outcomes were obtained from CN-HF. The univariate Cox proportional hazard model was used to screen the variates that might predict prognosis, and then the covariates with statistical significance were included in the multivariate Cox regression model to analyze the predictive value of baseline NT-proBNP on all-cause death. Spearman correlation analysis was used to evaluate the relationship between NT-proBNP and estimated glomerular filtration rate (eGFR), so as to further explore the predictive value of the interaction between renal dysfunction and NT-proBNP on death. Since NT-proBNP did not obey the binary normal distribution, it was expressed by the natural logarithm of NT-proBNP (LnNT-proBNP). Results: A total of 1 846 HFpEF patients were enrolled in this study, with an average age of 71.5 years, 1 017 males(55.1%), median NT-proBNP 860 ng/L, and median eGFR 73.9 ml·min^-1·1.73m^-2. After a median follow-up of 34 months, 213 (11.5%) patients died. Patients in the death group were older, with higher NYHA classification Ⅲ-Ⅳ ratio, longer hospital stay, higher serum potassium and NT-proBNP level, prevalence of complications of diabetes mellitus, arrhythmia and atrial fibrillation, use of angiotensin receptor antagonist(ARB), mineralocorticoid receptor antagonists (MRA), diuretic and digoxin was significantly higher in death group than in survival group. Body mass index (BMI), diastolic blood pressure, left ventricular ejection fraction (LVEF), hemoglobin, serum cholesterol(TC), serum triglycerides (TG) and eGFR, and use of angiotensin converting enzyme inhibitors (ACEI), statins and aspirin were lower in death group than in survival group. Univariate Cox regression analysis showed that NT-proBNP was a predictor of all-cause death in HFpEF patients (HR=2.522, 95%CI 2.040-3.119, P<0.001). Multivariate Cox regression analysis showed that the elevated NT-proBNP remains as the independent predictor of all-cause death in patients with HFpEF (HR=1.230, 95%CI 1.049-1.442, P=0.011) after adjusting for age, BMI, diastolic blood pressure, LVEF, hemoglobin, serum potassium, serum sodium, TC, serum high-density lipoprotein cholesterol (HDL-C), TG, eGFR, atrial fibrillation, as well as the treatment of ACEI/ARB, MRA, diuretics and digoxin. Spearman correlation analysis showed that LnNT-proBNP was negatively correlated with eGFR (r=-0.361, P<0.001), but there was no interaction between NT-proBNP and renal dysfunction in predicting death in HFpEF patients (P>0.05). Conclusion: The elevated level of NT-proBNP at admission is an independent predictor of all-cause mortality in HFpEF patients.

[Preliminary application of real-time fluorescence recombinase polymerase amplification in Candida albicans]

Objective: To explore the preliminary application effect of real-time fluorescence recombinase polymerase amplification (RPA) in the detection of Candida albicans. Methods: (1) Candida albicans standard strain and negative control bacteria of Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Candida glabrata standard strains of respectively 1 mL were collected and their DNA were extracted by yeast/bacterial genomic kit. The specificity of polymerase chain reaction (PCR), real-time fluorescent quantitative PCR, and real-time fluorescence RPA in detecting Candida albicans were analyzed. (2) One Candida albicans standard strain and one negative control bacteria of Candida glabrata standard strain were collected, resuscitated, and counted. Candida albicans was diluted 10 times to 1×10(7) to 1×10(1) colony-forming unit (CFU)/mL. The DNA of the two bacteria were extracted as experiment (1). The sensitivity of PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA in detecting Candida albicans were analyzed. The number of cycles for amplification curve to reach the threshold in real-time fluorescent quantitative PCR, and time of appearance of specific amplification curve in real-time fluorescence RPA were recorded and compared with the results in PCR. The detection limit and rate of the above-mentioned 3 methods in detecting Candida albicans were analyzed, and the correlation between concentration of Candida albicans in real-time fluorescence RPA and detection time was analyzed. (3) One standard strain of Candida albicans was collected, and the DNA was extracted as experiment (1) and detected by PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA. The total detection time of the above-mentioned 3 methods was recorded, respectively. (4) The DNA of 31 clinical samples of suspected Candida albicans infection and 1 clinical sample of Candida albicans collected from cotton swab were extracted, PCR and real-time fluorescence RPA were carried out, and the positive detection rates of the above-mentioned methods were calculated. The DNA of the clinical samples with positive results in both PCR and real-time fluorescence RPA were extracted by yeast/bacterial genomic kit, chelex-100 boiling method, and repeatedly freeze-thawing with liquid nitrogen method, and real-time fluorescence RPA and PCR were carried out. The negative control bacteria was Candida glabrata in real-time fluorescence RPA, while negative control bacteria in PCR were the same as experiment (1). The positive results in PCR and real-time fluorescence RPA were observed and time for amplification curve to reach the fluorescence threshold in real-time fluorescence RPA was recorded, respectively. Data were processed with linear correlation analysis and t test. Results: (1) Three methods showed positive results in detecting standard strain of Candida albicans, and none of the 5 negative control bacteria showed positive results. (2) As the concentration of bacterial solution of Candida albicans decreased, the number of cycles for the amplification curve to reach the threshold increased in real-time fluorescent quantitative PCR, the time for appearance of specific amplification curve prolonged in real-time fluorescence RPA, and brightness of the gel strip weakened in PCR. None of the negative control bacteria in the above-mentioned 3 detection methods showed corresponding positive results. The detection limit of Candida albicans in real-time fluorescence RPA, PCR, and real-time fluorescent quantitative PCR was 1×10(1) CFU/mL. There was a significant negative correlation between the concentration of Candida albicans and the detection time in real-time fluorescence RPA (r=-0.95, P<0.01). The positive detection rates of PCR and real-time fluorescent quantitative PCR for Candida albicans of 1×10(1) to 1×10(7) CFU/mL were 100%. The positive detection rate of real-time fluorescence RPA for Candida albicans of 1×10(1) CFU/mL was 78%, and the positive detection rate of real-time fluorescence RPA for Candida albicans of 1×10(2) to 1×10(7) CFU/mL was 100%. (3) The total time of PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA detection for Candida albicans was 133, 93, and 35 min, respectively. (4) The positive detection rate of real-time fluorescence RPA for 31 clinical samples of suspected Candida albicans infection was 32.26% (10/31), which was slightly lower than 35.48% (11/31) of PCR. Eleven clinical samples showed positive results both in real-time fluorescence RPA and PCR detection. No positive result was observed in the negative control bacteria detected both by real-time fluorescence RPA and PCR. The DNA was extracted by yeast/bacterial genomic extraction kit and chelex-100 boiling method for real-time fluorescence RPA detection. The time for the amplification curve to reach the threshold was (438±13) and (462±12) s, respectively, which was close (t=1.32, P>0.05). The DNA was extracted by repeatedly freeze-thawing with liquid nitrogen method for real-time fluorescence RPA, and the time for the amplification curve to reach the threshold in real-time fluorescence RPA was (584±15) s, which was significantly longer than that in the other 2 methods (t=7.55, 6.39, P<0.01). Conclusions: Real-time fluorescence RPA has advantages of rapid detection, simple operation, high sensitivity, and good specificity in detecting Candida albicans, which is worthy of clinical application.

[Effects of highly selective branches neurotomy of vidian nerve with low temperature plasma on vasoactive intestinal peptide in nasal mucosal cells of patients with allergic rhinitis]

Objective:The aim of this study is to investigate the effect of highly selective branches neurotomy of vidian nerve with low temperature plasma on the level of vasoactive intestinal peptide in nasal mucosa of patients with allergic rhinitis. Method:Fifty patients with allergic rhinitis were selected as the experimental group. At the same time, 50 normal adults in our hospital were selected as the control group. Highly selective branches neurotomy of vidian nerve with low temperature plasma was performed to observe the changes of vascular intestinal peptide levels in patients with nasal mucosa and the clinical efficacy. Result:Fifty patients with allergic rhinitis were treated with highly selective branches neurotomy of vidian nerve with low temperature plasma. 28 cases have significant effect and the curative effect was 64.3%-92.1% (average was 77.4±4.5)%; 19 were effective and the therapeutic effect was 31.2%-56.4%, with an average of (43.2±2.9)%; only 3 cases were ineffective, and the therapeutic effect was less than 30%. There was significant difference between the two groups after treatment (P<0.05). The optical density of vasoactive intestinal peptide was (1 723.3±215.4) and (2 732.3±324.5) in the preoperative and postoperative groups, respectively, with significant differences (P<0.05). The optical density of vasoactive intestinal peptide in the control group was (1 855.4±429.3), which was significantly different from that in the experimental group before operation (P<0.05). The difference between the control group and the experimental group after operation have no statistically significant (P>0.05). Conclusion:Highly selective branches neurotomy of vidian nerve with low temperature plasma can significantly reduce the level of vasoactive intestinal peptide in nasal mucosa of patients with allergic rhinitis, alleviate the symptoms of nasal congestion and paroxysmal sneezing, and improve the prognosis of patients.

[Application of recombinase polymerase amplification in the detection of Pseudomonas aeruginosa]

Objective: To establish an optimized method of recombinase polymerase amplification (RPA) to rapidly detect Pseudomonas aeruginosa in clinic. Methods: (1) The DNA templates of one standard Pseudomonas aeruginosa strain was extracted and detected by polymerase chain reaction (PCR), real-time fluorescence quantitative PCR and RPA. Time of sample loading, time of amplification, and time of detection of the three methods were recorded. (2) One standard Pseudomonas aeruginosa strain was diluted in 7 concentrations of 1×10(7,) 1×10(6,) 1×10(5,) 1×10(4,) 1×10(3,) 1×10(2,) and 1×10(1) colony forming unit (CFU)/mL after recovery and cultivation. The DNA templates of Pseudomonas aeruginosa and negative control strain Pseudomonas putida were extracted and detected by PCR, real-time fluorescence quantitative PCR, and RPA separately. The sensitivity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (3) The DNA templates of one standard Pseudomonas aeruginosa strain and four negative control strains (Staphylococcus aureus, Acinetobacter baumanii, Candida albicans, and Pseudomonas putida) were extracted separately, and then they were detected by PCR, real-time fluorescence quantitative PCR, and RPA. The specificity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (4) The DNA templates of 28 clinical strains of Pseudomonas aeruginosa preserved in glycerin, 1 clinical strain of which was taken by cotton swab, and negative control strain Pseudomonas putida were extracted separately, and then they were detected by RPA. Positive amplification signals of the clinical strains were observed, and the detection rate was calculated. All experiments were repeated for 3 times. Sensitivity results were analyzed by GraphPad Prism 5.01 statistical software. Results: (1) The loading time of RPA, PCR, and real-time fluorescence quantitative PCR for detecting Pseudomonas aeruginosa were all 20 minutes. In PCR, time of amplification was 98 minutes, time of gel detection was 20 minutes, and the total time was 138 minutes. In real-time fluorescence quantitative PCR, amplification and detection could be completed simultaneously, which took 90 minutes, and the total time was 110 minutes. In RPA, amplification and detection could also be completed simultaneously, which took 15 minutes, and the total time was 35 minutes. (2) Pseudomonas putida did not show positive amplification signals or gel positive results in any of the three detection methods. The detection limit of Pseudomonas aeruginosa in real-time fluorescence quantitative PCR and PCR was 1×10(1) CFU/mL, and that of Pseudomonas aeruginosa in RPA was 1×10(2) CFU/mL. In RPA and real-time fluorescence quantitative PCR, the higher the concentration of Pseudomonas aeruginosa, the shorter threshold time and smaller the number of cycles, namely shorter time for detecting the positive amplified signal. In real-time fluorescence quantitative PCR, all positive amplification signal could be detected when the concentration of Pseudomonas aeruginosa was 1×10(1)-1×10(7) CFU/mL. In RPA, the detection rate of positive amplification signal was 0 when the concentration of Pseudomonas aeruginosa was 1×10(1) CFU/mL, while the detection rate of positive amplification signal was 67% when the concentration of Pseudomonas aeruginosa was 1×10(2) CFU/mL, and the detection rate of positive amplification signal was 100% when the concentration of Pseudomonas aeruginosa was 1×10(3)-1×10(7) CFU/mL. (3) In RPA, PCR, and real-time fluorescence quantitative PCR, Pseudomonas aeruginosa showed positive amplification signals and gel positive results, but there were no positive amplification signals or gel positive results in four negative control strains of Acinetobacter baumannii, Staphylococcus aureus, Candida albicans, and Pseudomonas putida. (4) In RPA, 28 clinical strains of Pseudomonas aeruginosa preserved in glycerin and 1 clinical strain of Pseudomonas aeruginosa taken by cotton swab showed positive amplification signals, while Pseudomonas putida did not show positive amplification signal. The detection rate of positive amplification signal of 29 clinical strains of Pseudomonas aeruginosa in RPA was 100%. Conclusions: The established optimized RPA technology for fast detection of Pseudomonas aeruginosa requires shorter time, with high sensitivity and specificity. It was of great value in fast detection of Pseudomonas aeruginosa infection in clinic.

Microstructure, mechanical properties and superelasticity of biomedical porous NiTi alloy prepared by microwave sintering

Porous NiTi alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity in the range of 22-62%. The effects of porosities on the microstructure, hardness, compressive strength, bending strength, elastic modulus, phase transformation temperature and superelasticity of the porous NiTi alloys were investigated. The results showed that the porosities and average pore sizes of the porous NiTi alloys increased with increasing the contents of NH4HCO3. The porous NiTi alloys consisted of nearly single NiTi phase, with a very small amount of two secondary phases (Ni3Ti, NiTi2) when the porosities are lower than 50%. The amount of Ni3Ti and NiTi2 phases increased with further increasing of the porosity proportion. The porosities had few effects on the phase transformation temperatures of the porous NiTi alloys. By increasing the porosities, all of the hardness, compressive strength, elastic modulus, bending strength and superelasticity of the porous NiTi alloys decreased. However, the compressive strength and bending strength were higher or close to those of natural bone and the elastic modulus was close to the natural bone. The superelastic recovery strain of the trained porous NiTi alloys could reach between 3.1 and 4.7% at the pre-strain of 5%, even if the porosity was up to 62%. Moreover, partial shape memory effect was observed for all porosity levels under the experiment conditions. Therefore, the microwave sintered porous NiTi alloys could be a promising candidate for bone implant.

Characterization and molecular mapping of a dwarf mutant in wheat

A spontaneous dwarf mutant of wheat was found in an F5 generation line derived from a cross between Huamai No. 9 and Een No. 1 in 1998; it was named Huaai 01. We characterized the genetic pattern of Huaai 01 and mapped the gene controlling the dwarf trait. This dwarf mutant was found insensitive to exogenous gibberellic acid treatment, based on the length of the first leaf and the coleoptile at the seedling stage, suggesting that it plays a crucial role in the gibberellin response pathway. Genetic analysis revealed that a single gene that is partially recessive controls the dwarf phenotype in Huaai 01. We named the dwarfing gene Rht-B2. Simple sequence repeats (SSR) were examined as identifying markers linked to the Rht-B2 gene in an F2 population. We screened 904 pairs of primers and identified 5 SSR markers linked to the Rht-B2 gene. Two markers, barc1096 and xgwm495, were located on the flanking region of the Rht-B2 gene at genetic distances of 2.9 and 3.3 cM, respectively. Based on published SSR linkage data for wheat, the Rht-B2 gene was mapped to the long arm of chromosome 4B. This identification and characterization of the Rht-B2 dwarfing gene will facilitate its utilization in wheat breeding.

[Surgical exploration of the sentinel lymph nodes in the papillary thyroid carcinoma]

OBJECTIVE

To study the technique of sentinel lymph node mapping in the papillary thyroid carcinoma and its evaluation in the search for cervical metastases.

METHOD

Exploration of the sentinel lymph nodes of the papillary thyroid carcinoma by injection of methylene blue around the tumour among 25 patients during surgery. The nodes which stained blue and the other nodes removed by functional neck dissection were examined histologically after staining with hematoxylin-eosin-saffron (HES). We have evaluated the predictive value of the technique in mapping the cervical metastases in the sentinel lymph node.

RESULTS

Among the 25 patients, 22 patients presented sentinel lymph nodes (blue-stained), that is to say a rate of identification of 88%. At histological examination, 19 of the 22 patients had positive sentinel lymph nodes, of which 13 had also positive nodes not coloured with blue. The histological examination of patients without sentinel lymph node was negative.

CONCLUSION

The technique of the sentinel lymph node has a strong positive predictive value in the search for cervical node metastases in the papillary thyroid carcinoma.

[Non-linear compression for noises in non-contact vital signs detecting system]

A method for compressing the noises overlapping in the breath and heart signals of human beings, detected by the non-contact vital signs detecting system during the display of the waveforms in time domain, is discussed in this paper in detail. And what's more, the problem that the noise level is changed along with the increase of the gain of AD data-acquisition card and the display--gain of the software is solved by researching into the threshold of noise-level contraction in two types of circumstance in the lab, and the result of the breath and heart signal in the condition of lower noise is realized as well.

[Clinical observation on treatment of non-small cell lung cancer with Chinese herbal medicine combined with bronchial arterial infusion chemotherapy]

OBJECTIVE

To explore the effect of treatment for non-small cell lung cancer (NSCLC) with Chinese herbal medicine (CHM) combined with bronchial arterial infusion chemotherapy (BAIC).

METHODS

Patients with moderate or advanced NSCLC were randomly divided into two groups, the 39 patients in the treated group treated with CHM plus BAIC therapy and 37 in the control group treated with BAIC alone. The short-term therapeutic effect, long-term survival rate, changes of clinical principal symptoms, quality of life and peripheral blood pictures in the two groups were observed and compared.

RESULTS

After treatment the rate of CR + PR + NC in the treated and the control group was 92.31% and 70.27% respectively, the inter-group comparison showed a significant difference (P < 0.05). The 0.5-, 1- and 2-year survival rate in the treated group was 79.49%, 56.41% and 51.28% respectively and in the control group, 72.97%, 51.35% and 24.32% respectively. The 2-year survival rate in the former was better than that in the latter (P < 0.05). Moreover, the improvement of clinical symptoms, Karnofsky scoring, body weight and peripheral blood picture in the treated group was superior to that in the control group.

CONCLUSION

Therapeutic effect of BAIC could be enhanced by combining it with CHM.

[The study on non-contact detection of breathing and heartbeat based on radar principles]

The paper introduces the design of hardware and software of non-contact detection system for breathing and heartbeat in human body with radar principles and technology. The detection technology is discussed. Under conditions of the illuminating power P < 1 mW and the distance S < 10 m, the non-contact breathing and heartbeat measurement, can be in different positions and with different clothing on the subject. The results show that the system with the technology has a high sensitivity, and is harmless to the health. It is a practicable non-contact detection technology for breathing and heartbeat of human body.

[Methylcobalamin, antagonist to transient ototoxic action of gentamicin]

OBJECTIVE

To explore whether is methylcobalamin effective in prophylaxis of AmAn ototoxic action.

METHOD

We attempted to use a single injection of gentamicin(125 mg/Kg b.i.w.) to make an animal (guinea pig) model of transient sensory disturbance of hearing, and by a series observation of the changes in ECochG to find out the antagonistic action of methylcobalamin which was simultaneously given to animals(1 mg/Kg, i.m.) followed injection of gentamicin.

RESULT

1. The transient ototoxic action of gentamicin may cause delay of latency and diminution of amplitude of CAP N1 and N2 in animals with a single injection of gentamicin. Though the interval between N1 and N2 prolonged, the changes were still within normal ranges. 2. By contrast, the changes of delay at N1 and N2 as mentioned above were significantly improved in animals administered simultaneously with methylcobalamin.

CONCLUSION

It indicated that in addition to the improvement of physiologic function of nerve fibres, methylcobalamin may be also an agent to prevent the transient ototoxic action of gentamicin. Due to methylcobalamin acts as a methyl donor, it participates the synthesis of SAM (S-adenosylmethionine) and thus products GSH(Glutathion SH), the latter may inhibit ototoxic side-effects of gentamicin.

Functional, histological, and inflammatory changes in chronically rejecting small bowel transplants

Our aim was to develop a model of chronic rejection (CR) in small bowel allografts, and to study the changes occurring in these grafts. Small bowel transplantation was performed using the DA to AS rat strain combination. Short-term (5 mg/kg intramuscular, from days -2 to +9), or long-term cyclosporin treatment (5 mg/kg, 3 times a week until day 50) was given to prevent acute rejection. Controls were untreated allografts, DA isografts with and without cyclosporin, and normal DA and AS rats. They were followed for 50 and 100 days after transplantation. Recipients of a syngeneic graft lost weight during the first week after transplantation, but started to regain weight and kept growing thereafter. Histology showed normal bowel architecture with normal mesenteric lymph nodes and Peyers patches. Vigorous acute rejection occurred in the untreated allografts. Animals had persistent weight loss, and were killed between 6-13 days after transplantation. No clinical signs of graft-versus-host disease were seen. Histology showed end-stage acute rejection. In both cyclosporin-treated allografted groups the postoperative course was as in the isografted animals. However, all animals had histologic signs of CR by 50 and 100 days after transplantation. Changes were most prominent in the mesentery. Serositis with increased vascularity, inflammation with sclerosis, and patchy myointimal proliferation with endothelialitis of the mesenteric vessels were found. Changes in the bowel were patchy and included some thickening of the muscle coat, crypt hyperplasia, scattered necrotic cells in the crypts, slight blunting of villi and loss of goblet cells. Infiltrating cells in the mesentery and bowel consisted mainly of CD 4+ cells, CD 8- T-cells and monocytes/macrophages. Lactulose-mannitol urinary excretion ratio was significantly increased in short-term cyclosporin treated allografts at days 50 and 100 posttransplant. Serum albumin levels were significantly lowered in this group at both time points examined. We developed two models in which CR occurs after small bowel transplantation. Long-term cyclosporin treatment delayed the development of CR, since functional abnormalities were only seen in the animals that were treated with short-term cyclosporin.

[An in vitro of acrylonitrile inducing early damage on buccal mucosa of murine]

ObJECTIVE:Understand the change and damage of rats and mice buccal mucosa tissue structure posioned by acrylonitrile and alcohol. METHODS: Using optical microscope and transmitted electron microscope (TEM) techniques, observed the structure of rats and mice buccal mucosa which posioned by acrylonitrile and alcohol for 13 weeks in different dosages. RESULTS: Acrylonitrile can damage the ultrastructure of the cells and lead to precancerous dysplasia,such as enlargement and deformation of nuclei, reducing of desmosomes and hemidesmosomes,break of basement membrane,swelling and denaturalization of mitochondrion. The degree of damage was correlated with its dosage. Alcohol can increase the damage caused by acrylonitrile. CONCLUSION: Both acrylonitrile and alcohol can destroy the ultrastructure of cells,TEM is helpful for diagnosing disease in their early stage,and buccal mucosa can be used as a window for observing the disease caused by many toxic factors.

Effects of centrally administered angiotensin on sympathetic nerve activity and blood flow to the kidney in conscious rats

The effects of intracerebroventricular (i.c.v.) administration of different doses (10 pg-100 ng) of angiotensin II (AII) on renal sympathetic nerve activity (RSNA), mean arterial blood pressure (MAP), heart rate (HR), renal blood flow and femoral blood flow have been examined in conscious rats. Administration of AII (10 ng) through a chronically implanted cannula induced an increase in MAP (20-22 mmHg), a decrease in HR (24 bpm), a decrease in RSNA by 57%, a decrease of femoral blood flow by 21% but no change in renal blood flow. The effects on MAP, HR and RSNA are greatly attenuated by the prior i.c.v. injection of an AII-antagonist saralasin. In anesthetized rats, renal denervation significantly attenuated an increase in urinary sodium excretion induced by i.c.v. injection of AII. Since activation of the renal nerve is known to induce sodium reabsorption from the renal tubule and renin release, the relevance of the present finding is discussed in relation to the effect of AII on sodium excretion.

Inhibition of renal sympathetic nerve activity of anesthetized rats by intracerebroventricular administration of angiotensin II

Effects of intracerebroventricular (i. c. v.) administration of angiotensin II (AII) on renal sympathetic nerve activity (RSNA), arterial pressure, and heart rate were examined in rats anesthetized with a mixture of urethane and alpha-chloralose. Administration of AII evoked an increase in arterial pressure and a decrease in RSNA with no significant change in heart rate. Prior i. c. v. administration of an AII antagonist, saralasin, greatly attenuated the pressor response and inhibition of RSNA induced by i. c. v. AII. Rats with sinoaortic denervation showed the same magnitude pressor response and decrease in RSNA as intact animals. The result suggests that central AII directly inhibits RSNA via AII specific receptors.

[Combination therapy of small cell anaplastic carcinoma of the lung and the role of prophylactic whole brain irradiation--report of 39 cases]

A series of 39 cases of small cell anaplastic carcinoma of the lung treated by combination of chemotherapy and radiotherapy is reported. The role of prophylactic whole brain irradiation in this combination is emphasized. Apart from 2 cases whose treatment was interrupted, the chief symptoms of the other 37 were significantly improved by irradiation. The response rate was over 86% and the median survival was 8 months. The 2-year survival rates of the patients with or without brain irradiation (group A and B) were 26.7% and 9.1% respectively. None of the group A patients (15 cases) developed brain metastasis while 4 (18%) of the group B patients (22 cases) did. The results prove the validity of the prophylactic whole brain irradiation. In this series, the mortality of liver metastasis amounted to 38%. The authors believe that prophylactic liver irradiation may reduce the metastases into the liver and prolong the survival.