A compact Class D RF power amplifier for mobile nuclear magnetic resonance systems

A 20 MHz Class D amplifier with an output of 100 W of RF power has been developed. The compact size printed circuit board area of 50 cm² and efficiency of 73% make it suitable for mobile nuclear magnetic resonance (NMR) systems. Test results show that the rise and ring down times of the amplifier are less than 0.2 μs, and it is capable of producing constant amplitude pulses as short as 2 μs. Experiments using a Carr Purcell Meiboom Gill pulse sequence with a NMR MOUSE sensor confirm that the Class D amplifier is suitable for mobile NMR applications.

Allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population

KIR2DL2 and KIR2DL3 segregate as alleles of the same killer cell immunoglobulin-like receptor (KIR) gene locus. They have been associated with viral infectious diseases and certain cancers and their allelic information may help to better comprehend mechanisms. The allelic polymorphism of KIR2DL2/2DL3 has been shown to influence their binding specificity and affinity to the HLA-C1 ligands. The present study aims to investigate the distribution of the allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population using sequence-specific primer polymerase chain reaction (PCR-SSP) and PCR-sequence-based typing (SBT) at the entire coding sequence. Of the 306 tested individuals, 1.96% were positive for KIR2DL2 only, 78.10% for KIR2DL3 only, and 19.93% for both KIR2DL2 and 2DL3. KIR2DL3 showed a high degree of diversity in the study population with 15 alleles detected including 8 novel ones. The predominant 2DL3 allele in the study population is 2DL3*00101 (92.81%) followed by 2DL3*00201 (24.18%), 2DL3*023 (4.25%), and 2DL3*00109 (1.31%). The remaining 11 2DL3 alleles all had a frequency below 1%. Three detected 2DL2 alleles were 2DL2*00301 (18.95%), 2DL2*00101 (3.59%), and the novel 2DL2*013 (0.33%). These results provide further insight into the KIR gene diversity in Southern Chinese and may help to better understand the role played by KIR genes in associated diseases.

A novel KIR2DL3 variant allele, KIR2DL3*032, which has arisen by a missense mutation in codon 231

The novel 2DL3*032 allele differs from the closest allele KIR2DL3*0010101 by a non-synonymous mutation in exon 7.

HLA-A*11:188: a new allele identified by sequence-based typing in a Chinese blood donor

A novel allele HLA-A*11:188 differs from HLA-A*11:01:01 by a single mutation at position 439 in exon 3.

Identification of the novel KIR3DL1*01505 allele from southern Chinese Han individual

The novel KIR3DL1*01505 allele differs from the closest allele KIR3DL1*0150201 by a single silent mutation.

Identification of the novel HLA-C*03:240 allele

HLA-C*03:240 differs from HLA-C*03:42 by a single nucleotide substitution that results in a missense mutation Tyr 99 Cys (TAT to TGT).

Identification of a novel HLA-C*04 allele, HLA-C*04:162

HLA-C*04:162 differs from the closely matching allele C*04:01:01:01 by one nucleotide substitution in exon 4 at position 883 A/G.

Reveals new lung adenocarcinoma cancer genes based on gene expression

BACKGROUND

Lung adenocarcinoma (LAC) is the most common type of lung cancer, accounting for 30-35% of all cases.

AIM

In this study we aim to predict potential genes and confirm pathways which are associated with LAC.

MATERIALS AND METHODS

By using the meta-analysis method, GSE10072 and GSE 2514 datasets were merged to find potential genes and pathways which are associated with LAC.

RESULTS

Our analysis indicated identified differentially expressed genes enriched in multicellular organismal metabolic process, gland development, and urogenital system development. Further, we predicted genes including EGF-like domain might be the potential target genes for further study, such as NGX6, MUC17, and Nel. In addition, a number of genes that associated with axon guidance, focal adhesion, and complement and coagulation cascades pathway might be also involved in LAC in a direct or indirectly manner.

CONCLUSIONS

Our analysis indicated identified differentially expressed genes enriched in multicellular organismal metabolic process, gland development, and urogenital system development We anticipate numerous advances in LAC research in the coming years based on our meta-analysis.

Urinary excretion and renal production of hepatocyte growth factor in children with Henoch-Schönlein purpura

This study measured urinary excretion and renal levels of hepatocyte growth factor (HGF) in children with Henoch-Schönlein purpura (HSP), examining the relationship between HGF, proteinuria and renal pathological changes. Seventy-eight patients with HSP aged 6 - 18 years were divided into three groups, based on urinary albumin excretion rate. Urinary HGF concentration was measured by enzyme-linked immunosorbent assay. Renal biopsies were performed in 22 patients; renal levels of HGF protein were determined immunohistochemically. Compared with controls, urinary HGF was significantly increased in patients with normoalbuminuria and microalbuminuria, especially in those with microalbuminuria; no differences were observed between patients with macroalbuminuria and controls. Little or no HGF was present in normal kidney, but HGF was present in renal tissue in all HSP patients, particularly those with microalbuminuria. Urinary HGF was strongly correlated with the presence of renal HGF. These results suggest that HGF is associated with proteinuria and renal pathological changes in children with HSP. The detection of urinary HGF in children with HSP may be a non-invasive, effective, method for early diagnosis of renal injury.

Upregulation of endothelial and inducible nitric oxide synthase expression by reactive oxygen species

BACKGROUND

The effect of reactive oxygen species (ROS) on nitric oxide synthase (NOS) expression remains uncertain. This study explored the effect of increased ROS activity on NOS expression in vitro in human coronary artery endothelial cells (HCAECs) grown in culture and in intact animals.

METHODS

Endothelial NOS (eNOS) expression and nuclear factor kappaB (NFkappaB) activation were determined in HCAECs grown in culture and exposed to oxidative stress with xanthine-xanthine oxidase (X-XO) generated superoxide, H(2)O(2), or glutathione depletion with buthionine sulfoximine (BSO) for 24 h. In parallel experiments, cells were treated with a nitric oxide (NO) scavenger (hemoglobin), and with an NO donor S-nitroso-N-acetyl penicillamine (SNAP)]. In addition, eNOS and inducible NOS (iNOS) expressions were determined in rats treated with either BSO or vehicle for 48 h.

RESULTS

Increases in ROS activity, achieved by exogenous superoxide and H(2)O(2) or by glutathione depletion, upregulated the expression of eNOS at both transcriptional and translational levels in HCAECs. Similar effects were seen with the non-radical NO scavenger, hemoglobin. The upregulatory action of hemoglobin on eNOS messenger RNA (mRNA) and protein expressions was overcome by the NO donor, SNAP, thereby suggesting that there is a negative feedback regulation of eNOS by NO. Nuclear translocation of NFkappaB (p65) was noted within 5 min of exposure to H(2)O(2) and at least 15 min after exposure to superoxide or BSO. Induction of oxidative stress by glutathione depletion led to upregulation of renal and aorta eNOS and iNOS in live animals.

CONCLUSIONS

An increase in ROS activity upregulates NOS expression in vitro in HCAECs grown in culture, and also in vivo in animals. This effect appears to be, in part, mediated by limiting the availability of NO, thereby exerting a negative feedback influence on NOS expression through activation of NFkappaB.

Dihydropyrimidine dehydrogenase activity correlates with fluorouracil sensitivity in breast cancer

The fluoropyrimidine drug fluorouracil (FU) is one of the most frequently prescribed chemotherapeutic drugs for the curative and palliative treatment of various cancer patients. The identification of biological factors associated with tumors either responsiveness or resistance to FU chemotherapy, including FU, is increasingly being recognized as an important field of clinical cancer research.

AIM

to analyze the relationship between intra-tumoral dihydropyrimidine dehydrogenase (DPD) level and FU chemosensitivity, as DPD is the initial and rate-limiting enzyme in the catabolism of FU.

MATERIALS AND METHODS

The histoculture drug response assay (HDRA) was performed for 54 patients. DPD expression was examined in 81 tumor samples from breast cancer patients received two cycles of FU-based primary chemotherapy before operation.

RESULTS

We found that intra-tumoral DPD enzyme activity was inversely correlated with FU cytotoxicity. We also revealed that low DPD expression was correlated with clinical response to FU-based primary chemotherapy.

CONCLUSIONS

Our study indicated that DPD is a promising molecular maker for identifying tumor cells sensitivity in breast cancer patients receiving FU-based chemotherapy.

The importance of company: Na+ and Cl- influence substrate interaction with SLC6 transporters and other proteins

SLC6 transporters, which include transporters for gamma-aminobutyric acid (GABA), norepinephrine, dopamine, serotonin, glycine, taurine, L-proline, creatine, betaine, and neutral cationic amino acids, require Na+ and Cl- for their function, and this review covers the interaction between transporters of this family with Na+ and Cl- from a structure-function standpoint. Because detailed structure-function information regarding ion interactions with SLC6 transporters is limited, we cover other proteins cotransporting Na+ or Cl- with substrate (SLClA2, PutP, SLC5A1, melB), or ion binding to proteins in general (rhodanese, ATPase, LacY, thermolysine, angiotensin-converting enzyme, halorhodopsin, CFTR). Residues can be involved in directly binding Na+ or Cl-, in coupling ion binding to conformational changes in transporter, in coupling Na+ or Cl- movement to transport, or in conferring ion selectivity. Coordination of ions can involve a number of residues, and portions of the substrate and coupling ion binding sites can be distal in space in the tertiary structure of the transporter, with other portions that are close in space thought to be crucial for the coupling process. The reactivity with methanethiosulfonate reagents of cysteines placed in strategic positions in the transporter provides a readout for conformational changes upon ion or substrate binding. More work is needed to establish the relationships between ion interactions and oligomerization of SLC6 transporters.

Immunocapture UPPCR combined with DGGE for rapid detection of Shigella species

AIMS

To develop an immunocapture universal primer PCR (iUPPCR) combined with denaturing gradient gel electrophoresis (DGGE) and evaluate it as a method permitting rapid detection of Shigella species and their serotypes.

METHODS AND RESULTS

This method amplifying the conserved regions of bacterial 16S rRNA genes of different species or serotypes of Shigella dysentery bacilli captured and enriched by polyvalent antibodies can detect and distinguish causative pathogens rapidly. Four serotypes from three Shigella species including Shigella dysenteriae serotype 1, Shigella boydii serotype 1, Shigella flexneri serotypes 1a and 3a were examined.

CONCLUSION

Our approach could be adopted for not only axenic bacterial population but also mixed communities and achieve rapid detection of various bacteria from the same genus or species in one sample.

SIGNIFICANCE AND IMPACT OF THE STUDY

The iUPPCR-DGGE method was shown to be more convenient than serotype-specific-antibody-based method of iUPPCR for Shigella species detection and it could be also applied to the quick detection for other kinds of pathogens with many serotypes.

Thymidylate synthase predicts for clinical outcome in invasive breast cancer

Thymidylate synthase (TS) is a major target of 5-fluorouracil (5-FU) and dihydropyrimidine dehydrogenase (DPD) is a rate-limiting enzyme in the degradation of 5-FU. Whether TS or DPD could be used as valuable parameters for 5-FU sensitivity in clinical patients are largely unknown. We analyzed TS and DPD expression in breast carcinomas to evaluate the clinicopathological significance of these enzymes in patients with invasive breast cancer receiving 5-FU-based chemotherapy. A total of 197 patients with invasive ductal carcinoma were included in our study. Both the TS and DPD expression were analyzed using immunohistochemical method for all the surgical samples. Sixty-three out of 197 (31.97%) patients are positive for TS expression, and 77 out of 197 (39.09%) patients are positive for DPD expression. TS expression was not correlated with DPD expression. Patients with TS-positivity had aggressive phenotype including large tumor size, low differentiation and nodal metastasis. DPD expression is not related with phenotype or prognosis. Multivariate analysis demonstrated that TS expression was an independent prognostic factor for both disease-free and overall survival. The current study demonstrated that TS but not DPD expression was associated with both progression and prognosis in breast cancer receiving 5-FU-based chemotherapy. TS expression in the primary tumor might be useful as a predictive parameter for the efficacy of 5-FU-based chemotherapy for breast cancer.

Chinese medicinal herbs for acute bronchitis

BACKGROUND

Acute bronchitis is one of the most common diagnoses made by primary-care physicians. It is traditionally treated with antibiotics, (although the evidence for their effectiveness is weak and modest at best), and other even less effective treatments. Chinese medicinal herbs have been also used as treatment.

OBJECTIVES

This review aims to summarise the existing evidence on the comparative effectiveness and safety of Chinese medicinal herbs for treating uncomplicated acute bronchitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2005), which includes the Cochrane Acute Respiratory Infections Group's specialised register; The Chinese Cochrane Centre's Controlled Trials Register (up to December 2004); MEDLINE (1966 to March Week 1, 2005); EMBASE (1988 to December 2004); and the Chinese Biomedical Database (CBM) (1980 to December 2004).

SELECTION CRITERIA

Randomised controlled trials comparing Chinese medicinal herbs with placebo, antibiotics or other Western medicines for the treatment of uncomplicated acute bronchitis.

DATA COLLECTION AND ANALYSIS

At least two authors extracted data and assessed trial quality.

MAIN RESULTS

Four trials reported the time to improvement of cough, fever, and rales associated with bronchitis and showed that patients treated with Chinese herbs had a shorter duration of signs and symptoms. Two trials reported the proportion of patients with improved signs and symptoms at follow up and showed that Chinese herbs were beneficial in terms of relief of signs and symptoms. Thirteen trials analysed the data on physician global assessment of improvement at follow up. Nine of thirteen trials showed that Chinese herbs were superior to routine treatment and the other four trials showed a similar effect to routine treatment. In general, Chinese herbs appeared beneficial. Only one trial reported on adverse effects during treatment.

AUTHORS' CONCLUSIONS

There is insufficient quality data to recommend the routine use of Chinese herbs for acute bronchitis. The benefit found in this systematic review could be due to publication bias and study-design limitations of the individual studies. In addition, the safety of Chinese herbs is unknown due to the lack of toxicological evidence on these Chinese herbs, though adverse events are rarely reported. Chinese herbs should be used carefully.

[Adverse drug reaction and rational use of levofloxacin: a prospective study]

OBJECTIVE

To study the rate of adverse drug reaction(ADR) and the rational use of levofloxacin among in-patients.

METHOD

All in-patients treated with levofloxacin were prospectively observed in 7 hospitals of Beijing.

RESULTS

One hundred and five ADR cases were found in 2,661 patients injected with levofloxacin. The ADR rate was 3.9% while 4.8% of them were classified as severe cases. All severe ADR cases had a nature of double infections. The ADR occurrence was related to older age, irrational drug use, combined medicine and allergic history. The rate of levofloxacin irrational use was 19.9%, especially in the elderly population, due to too long or too short course of treatments.

CONCLUSION

Levofloxacin is viewed as a safe injection in clinical practice, however, combined medicine and elderly patients should be paid more attention when on administration of this medication. The irrational use of levofloxacin was recognized as one of the main reasons causing the increase of ADR.

Effect of pH and soybean cultivars on the quantitative analyses of soybean rhizobia populations

Quantitative analyses of fast- and slow-growing soybean rhizobia populations in soils of four different provinces of China (Hubei, Shan Dong, Henan, and Xinjiang) have been carried out using the most probable number technique (MPN). All soils contained fast- (FSR) and slow-growing (SSR) soybean rhizobia. Asiatic and American soybean cultivars grown at acid, neutral and alkaline pH were used as trapping hosts for FSR and SSR strains. The estimated total indigenous soybean-rhizobia populations of the Xinjiang and Shan Dong soil samples greatly varied with the different soybean cultivars used. The soybean cultivar and the pH at which plants were grown also showed clear effects on the FSR/SSR rations isolated from nodules. Results of competition experiments between FSR and SSR strains supported the importance of the soybean cultivar and the pH on the outcome of competition for nodulation between FSR and SSR strains. In general, nodule occupancy by FSRs significantly increased at alkaline pH. Bacterial isolates from soybean cultivar Jing Dou 19 inoculated with Xinjiang soil nodulate cultivars Heinong 33 and Williams very poorly. Plasmid and lipopolysaccharide (LPS) profiles and PCR-RAPD analyses showed that cultivar Jing Dou 19 had trapped a diversity of FSR strains. Most of the isolates from soybean cultivar Heinong 33 inoculated with Xinjiang soil were able to nodulate Heinong 33 and Williams showed very similar, or identical, plasmid, LPS and PCR-RAPD profiles. All the strains isolated from Xinjiang province, regardless of the soybean cultivar used for trapping, showed similar nodulation factor (LCO) profiles as judged by thin layer chromatographic analyses. These results indicate that the existence of soybean rhizobia sub-populations showing marked cultivar specificity, can affect the estimation of total soybean rhizobia populations indigenous to the soil, and can also affect the diversity of soybean rhizobial strains isolated from soybean nodules.

Adapalene gel 0.1%: effective and well tolerated in the topical treatment of acne vulgaris in Chinese patients

Acne vulgaris is a common dermatologic disease in Asian populations, as well as in Caucasians. Our objective was to evaluate the safety and efficacy of adapalene gel 0.1% in comparison with tretinoin gel 0.025% in Chinese patients with acne vulgaris. We used an 8-week, multicenter, randomized, controlled, investigator-masked, parallel group design study of adapalene gel 0.1% and tretinoin gel 0.025% in 150 Chinese patients with mild-to-moderate acne vulgaris. Our results showed that adapalene gel 0.1% had efficacy equivalent to tretinoin gel 0.025% against acne lesions in Chinese patients, with a more acceptable tolerability profile.

[The relationship between chemotherapy and multidrug resistance of lung cancer]

BACKGROUND

To investigate the relationship between multidrug resistance(MDR) and chemotherapy and the possibility of P-gp as a clinical prognostic indicator.

METHODS

P-gp, MDR1 gene product, was detected in 66 cases of relapsed lung cancer patients after chemotherapy and 131 lung cancer patients with no prior chemotherapy by immunohistochemistry.

RESULTS

The expressive level of P-gp in relapsed group after chemotherapy was much higher than that of non-chemotherapy group (P<0.05). A significant difference of P-gp expression existed between before and after chemotherapy for squamous cell carcinoma and SCLC (P<0.05), but not for adenocarcinoma. In non-chemotherapy group, lung cancer tissues with different histological types had different P-gp positive rates, which were adenocarcinoma, squamous cell carcinoma and SCLC in sequence from high to low (P<0.05). In relapsed group after chemotherapy, there was no significant difference among the three types of lung cancer (P>0.05). P-gp positive group had a significantly lower 3-year survival rate than negative group (P<0.05).

CONCLUSIONS

Chemotherapy may increase the incident rate of MDR in lung cancer. Adenocarcinoma is mainly primary MDR while SCLC and squamous cell carcinoma are mainly secondary to chemotherapy. P-gp expressive level can be used as a common clinical indicator for prognosis and chemotherapy in the patients with lung cancer.

[Epidemiological survey and analysis on bronchial asthma in Guangdong Province]

OBJECTIVE

To survey asthma prevalence and risk factors of asthma in Guangdong and then to provide a basic consideration for research and preventive and therapeutic poliaes for control of asthma.

METHODS

Using uniform scheme, procedures and questionnaire, performing stratified-cluster-disproportional-random-sampling survey for the population in six areas: Santou, Shenzhen, Zhanjiang, Shaoguan, Fushan and Guangzhou; quantitative sample the prevalence rate quantitated is 1.5% (P = 0.015, q = 0.985), a sampling number stratified = 178 x 0.985/0.015 = 11,689, if the whole province were stratified into six areas, a total of 70,134 persons were supposed to be investigated, in this survey 71,867 subjects were actually examined; all the original data were inputted into soft discs in the same form of data base structure variable definition table, and then were statistically analyzed with spas 8.0 for windows on P III/450 computer, all the prevalence rates were compared by chi 2 test.

RESULTS

In this survey 676 asthmatics were found, the overall prevalence rate was 0.94%, the ratio of male to female was 1.38:1; the rate of adults was 0.99% and that of children was 0.73%, three groups with higher prevalence were children of preschool period (age < 7 years, 1.03%), young period (age 18-25 years, 1.00%) and senile period (age 66-75 years, 2.99%); the rate of city (Fushan, 1.38%) was higher than that of rural area (Zhanjiang, 0.47%); the rate of old district (1.70%) was higher than that of the new district (0.23%) in Guangzhou and the rate of historic city (Fushan, 1.38%) was higher than that of the newly developed city (Shenzhen, 0.64%); risk factors found among 676 asthmatics, persons keeping pets (cat, dog, fowl, bird) in home were reported by 46.0% (311/676), those keeping cat was 43.1% (134/311), particularly those keeping cat and both cat and dog accounted for 61.7% (192/311). Persons often exposed to side-stream smoke were reported by 54.7%. Asthmatics with allergic rhinititis were reported by 38.2%. The attack contributed to change temperature or to inhale cold air was 41.6% respectively.

CONCLUSION

This survey had basically reflected the distribution, Frequency and intensity of asthma, the overall prevalence rate was 0.94% from which it would be estimated that there could be 670,000 asthmatics in Guangdong; the relative data will provide basis for research work concerned and mass prevention and treatment of asthma.

[Linkage analysis of chromosome 5 and asthma in a Chinese population]

OBJECTIVE

To investigate the linkage between asthma and 5q31-33 in a Chinese population.

METHODS

The linkage between microsatellite markers in 5q and asthma and allergy was tested by lod score analysis.

RESULTS

The linkage between asthma and 5q31-33 was not confirmed.

CONCLUSION

The genes at 5q31-33 are not likely to contribute to inheritance of asthma in this Chinese population.

[The study on the culture, freezing preservation and resuscitation of human trabecular cells in vitro]

PURPOSE

To establish the culture of human trabecular cells in vitro and study the freezing preservation and resuscitation.

METHODS

The trabecular specimens from human eyes were cultured in vitro and passaged 3 times, then the cultured cells were frozen and preserved. The frozen cells were resuscitated after one week, two weeks, one month and two months.

RESULTS

Cultured human trabecular cells were obtained. The frozen cells were resuscitated successfully. All of the resuscitated rates were more than 90%.

CONCLUSION

The human trabecular cells were cultured in vitro successfully, they can also be frozen and resuscitated, which will be helpful to the establishment of cDNA library and the screening of associated glaucomatous genes.