[Efficacy and safety of pegylated interferon α-2b injection (Y shape, 40 kD) in treatment of patients with genotype 1/6 chronic hepatitis C]

Objective: To investigate the efficacy and safety of the new investigational drug pegylated interferon α-2b (Peg-IFN-α-2b) (Y shape, 40 kD) injection (180 µg/week) combined with ribavirin in the treatment of patients with genotype 1/6 chronic hepatitis C (CHC), with standard-dose Peg-IFN-α-2a combined with ribavirin as a positive control. Methods: A multicenter, randomized, open-label, and positive-controlled phase III clinical trial was performed. Eligible patients with genotype 1/6 CHC were screened out and randomly divided into Peg-IFN-α-2b(Y shape, 40kD) group and Peg-IFN-α-2a group at a ratio of 2:1. The patients in both groups were given oral ribavirin for 48 weeks in addition and then followed up for 24 weeks after drug withdrawal. Abbott Real Time HCV Genotype II was used to determine HCV genotype, and Cobas TaqMan quantitative real-time PCR was used to measure HCV RNA level at 0, 4, 12, 24, 48, and 72 weeks. Adverse events were recorded in detail. The primary efficacy endpoint was sustained virological response (SVR), and a non-inferiority test was also performed. Results: A total of 561 patients with genotype 1/6 CHC were enrolled, among whom 529 received treatment; 90.9% of these patients had genotype 1 CHC. The data of the full analysis set showed that SVR rate was 69.80% (95% CI 65.00%-74.60%) in the trial group and 74.16% (95% CI 67.73%-80.59%) in the control group (P = 0.297 0). The data of the per protocol set (PPS) showed that SVR rate was 80.63% (95% CI 76.04%-85.23%) in the trial group and 81.33% (95% CI 75.10%-87.57%) in the control group (P = 0.849 8), and the 95% CI of rate difference conformed to the non-inferiority standard. The analysis of the PPS population showed that of all subjects, 47.9% achieved rapid virologic response, with a positive predictive value of 93.8%. The incidence rate of adverse events was 96.30% in the trial group and 94.94% in the control group, and the incidence rate of serious adverse events was 5.13% in the trail group and 5.06% in the control group. Conclusion: In the regimen of Peg-IFN-α combined with ribavirin for the treatment of genotype 1/6 CHC, the new investigational drug Peg-IFN-α-2b(Y shape, 40 kD) has comparable clinical effect and safety to the control drug Peg-IFN-α-2a.

Metronomic Cordycepin Therapy Prolongs Survival of Oral Cancer-Bearing Mice and Inhibits Epithelial-Mesenchymal Transition

Cordycepin (3'-deoxyadenosine) is a natural compound abundantly found in Cordyceps sinesis in natural and fermented sources. In this study, we examined the effects of cordycepin in a human oral squamous cell carcinoma (OSCC) xenograft model. Cordycepin was administered in a regular, low-dose and prolonged schedule metronomic therapy. Two doses of cordycepin (25 mg/kg, 50 mg/kg) were administrated five days a week for eight consecutive weeks. The tumor volumes were reduced and survival time was significantly prolonged from 30.3 ± 0.9 days (control group) to 56 days (50 mg/kg group, the day of tumor-bearing mice were sacrificed for welfare consideration). The weights of mice did not change and liver, renal, and hematologic functions were not compromised. Cordycepin inhibited the OSCC cell viability in vitro (IC50 122.4-125.2 μM). Furthermore, morphological characteristics of apoptosis, increased caspase-3 activity and G2/M cell cycle arrest were observed. In wound healing assay, cordycepin restrained the OSCC cell migration. Cordycepin upregulated E-cadherin and downregulated N-cadherin protein expression, implying inhibition of epithelial-mesenchymal transition (EMT). The immunohistochemical staining of xenograft tumor with E-cadherin and vimentin validated in vitro results. In conclusion, metronomic cordycepin therapy showed effective tumor control, prolonged survival and low toxicities. Cytotoxicity against cancer cells with apoptotic features and EMT inhibition were observed.

[Clinical analysis of the self made needle guide for the treatment of odontoid fracture]

OBJECTIVE

To analyze the curative effects and feasibility of the self regulating simple localizer through anterior approach for the treatment of odontoid fracture in adults.

METHODS

From June 2010 and December 2012, 6 patients with odontoid fracture underwent an anterior operation using a single hollow screw located by the self regulating simple localizer. There were 4 males and 2 females, aged from 28 to 55 years old with an average of 39.1 years. The injuries were caused by traffic accidents in 4 cases and falling injury from high in 2 cases. According to the classification of Anderson, 4 cases were type II and 2 cases were simple type III. All the patients underwent operations in 5 to7 days after injury with the mean of 5.9 days. None of the patients had a spinal cord injury. The safety and feasibility of the self made localizer were observed in follow up for fracture healing and clinical effects.

RESULTS

All the operations were successful with an average time of 50 min (ranged from 45 to 55 min) and the mean bleeding volume was 25 ml(ranged from 20 to 30 ml). No injuries of esophagus, trachea or nerve were found. All the patients were followed up from 8 to 16 months and all fractures were obtained bone healing. The flexion extension radiograph showed a well stability of atlantoaxial joint in last followed up.

CONCLUSIONS

The self regulating simple localizer is a minimally invasive, short time and safe method in treating odontoid fractures through anterior operation with hollow screw. It may be a reliable choice while without a professional localizer.

[Current status of occupational health and related countermeasures in Guangzhou, China]

OBJECTIVE

To investigate the current status of occupational health and related countermeasures in Guangzhou, China.

METHODS

Related data were collected from occupational poisoning accident investigation, diagnosis and identification of occupational diseases, and the occupational disease hazard reporting system, and the statistical data of occupational health in Guangzhou were analyzed retrospectively.

RESULTS

The number of enterprises reporting for occupational disease hazards in Guangzhou was 20 890, and the total number of workers was 1 457 583. The number of workers exposed to occupational hazards was 284 233, and the cumulative number of workers with occupational diseases was 1 502. There were many risk factors for occupational diseases in enterprises, and there were a large number of workers with occupational diseases, as well as newly diagnosed cases. From 2001 to 2014, the total number of cases of occupational diseases was 958.

CONCLUSION

The situation for the prevention and control of occupational diseases is grim in Guangzhou. Occupational health supervision and law enforcement should be enhanced, the three-level supervision system should be established and perfected, and the occupational health supervision system with a combination of "prevention, treatment, and protection" should be established and promoted, so as to gradually establish a technical service support system for occupational health.

Na (+) /Ca (2+) Exchanger 3 is Downregulated in the Hippocampus and Cerebrocortex of Rats with Hyperthermia-induced Convulsion

BACKGROUND

Na + /Ca 2+ exchanger (NCX) plays a crucial role in pentylenetetrazol-induced convulsion. However, it is unclear whether NCX is critically involved in hyperthermia-induced convulsion. In this study, we examined the potential changes in NCX3 in the hippocampus and cerebrocortex of rats with hyperthermia-induced convulsion.

METHODS

Twenty-one Sprague Dawley rats were randomly assigned to control group, convulsion-prone group and convulsion-resistant group (n = 7 in each group). Whole-cell patch-clamp method was used to record NCX currents. Both the Western blotting analysis and immunofluorescence labeling techniques were used to examine the expression of NCX3.

RESULTS

NCX currents were decreased in rats after febrile convulsion. Compared to the control group, NCX3 expression was decreased by about 40% and 50% in the hippocampus and cerebrocortex of convulsion-prone rats, respectively. Furthermore, the extent of reduction in NCX3 expression seemed to correlate with the number of seizures.

CONCLUSIONS

There is a significant reduction in NCX3 expression in rats with febrile convulsions. Our findings also indicate a potential link between NCX3 expression, febrile convulsion in early childhood, and adult onset of epilepsy.

Expression of EGFR, PIK3CA and PIK3CB in colorectal carcinoma

AIM: To investigate the expression of epidermal growth factor receptor (EGFR), PIK3CA and PIK3CB in colorectal cancer (CRC), to analyze the correlation between EGFR, PIK3CA and PIK3CB expression, and to discuss their role in the occurrence, development and targeted therapy of CRC.

METHODS: Immunohistochemistry was employed to detect the expression of EGFR, PIK3CA and PIK3CB in 120 CRC and 30 normal mucosa tissue sample (from the margin of the lesion > 5 cm), and the correlation between EGFR, PIK3CA and PIK3CB expression as well their relationship with clinicopathological factors were analyzed.

RESULTS: The positive expression rates of EGFR, PIK3CA and PIK3CB in CRC were 48%, 55.7% and 75.9%, respectively, which were significantly higher than those in tumor adjacent tissues (P < 0.05). In EGFR positive CRC tissues, 68.9% were PIK3CA positive and 72.4% was PIK3CB positive, while in EGFR negative CRC tissues, 43.5% were PIK3CA positive and 21.0% were PIK3CB positive. EGFR receptor expression was significantly different from the expression of PIK3CA and PIK3CB (P < 0.05). The expression of EGFR, PIK3CA and PIK3CB was positively correlated with tumor differentiation and lymph node metastasis in CRC (P < 0.05). Kaplan-Meier analysis revealed that the 5-year survival rate was significantly correlated with lymph node metastasis, EGFR, PIK3CA and PIK3CB expression. Multivariate analysis revealed that lymph node metastasis, EGFR, PIK3CA and PIK3CB expression could serve as independent predictive factors for overall survival.

CONCLUSION: EGFR, PIK3CA and PIK3CB are highly expressed in CRC, and their expression is closely correlated with tumor differentiation and lymph node metastasis. The high expression of PIK3CA and PIK3CB is not only correlated with the activation of EGFR, but also correlated with mutation by itself. The mutation of PIK3CA and PIK3CB genes in colorectal cancer may be a factor to influence therapies targeting EGFR in CRC.

Clinical significance of expression of PI3Kp110α, PI3Kp110β, Bcl-2 and CyclinD1 in primary colorectal cancer and lymph node metastases

AIM: To investigate the expression of phosphatidylinositol 3-kinase (PI3K)p110α, PI3Kp110β, B-cell lymphoma-2 (Bcl-2) and CyclinD1 in primary colorectal cancer (CRC) and lymph node metastases, and to analyze their correlations with clinicopathologic characteristics and prognosis of CRC.

METHODS: Immunohistochemistry was used to detect expression of PI3Kp110α, PI3Kp110β, Bcl-2 and CyclinD1 in 30 cases of normal colorectal mucosa, 52 cases of CRC without lymph node metastasis, 50 cases of primary CRC tissues and corresponding lymph node metastases. The correlations between PI3Kp110α, PI3Kp110β, Bcl-2, and CyclinD1 expression as well as their relationship with clinicopathologic characteristics and prognosis of CRC were analyzed.

RESULTS: The expression of PI3Kp110α and Bcl-2 in CRC without lymph node metastasis, primary CRC tissues and corresponding lymph node metastases was significantly higher than that in normal colorectal mucosa (P < 0.05). PI3Kp110β and CyclinD1 expression was also significantly increased in CRC without lymph node metastasis, primary CRC tissues, and corresponding lymph node metastases compared with the normal colorectal mucosa. What's more, PI3Kp110β and CyclinD1 expression was significantly increased in CRC with lymph node metastases compared with CRC without lymph node metastases (P < 0.05). Spearman analysis showed that PI3Kp110α expression was positively associated with Bcl-2 expression in the four groups (P < 0.05), PI3Kp110α expression was positively associated with CyclinD1 expression in normal colorectal mucosa, CRC without lymph node metastasis, and CRC with lymph node metastasis (P < 0.05), and PI3Kp110β expression was positively correlated with Bcl-2 and CyclinD1 expression in the four groups (P < 0.05). PI3Kp110α, PI3Kp110β and CyclinD1 expression was related to cancer cell differentiation and lymph node metastasis, and Bcl-2 expression was associated with cancer cell differentiation. Kaplan-Meier analysis showed that PI3Kp110α, PI3Kp110β, Bcl-2 and CyclinD1 were prognostic factors for CRC, and Cox proportional hazards regression analysis showed that PI3Kp110α and PI3Kp110β were independent prognostic factors for CRC.

CONCLUSION: PI3Kp110α, PI3Kp110β, Bcl-2, and CyclinD1 expression is increased in primary CRC tissues and lymph node metastases compared with normal mucosa, suggesting that they may play important roles in the development and progression of CRC. PI3Kp110α and PI3Kp110β promote cancer cell growth via Bcl-2 and CyclinD1 in CRC with lymph node metastases. PI3Kp110α, PI3Kp110β, Bcl-2 and CyclinD1 are associated with tumor cell differentiation and CRC metastasis. PI3Kp110α and PI3Kp110β are independent prognostic factors for CRC.

Expression of PIK3CA, PIK3CB and proteins associated with multidrug resistance in colorectal carcinoma

AIM: To investigate the clinical significance of expression of PIK3CA, PIK3CB and proteins associated with multidrug resistance (MDR) in colorectal cancer (CRC) and to analyze their correlations.

METHODS: Immunohistochemistry was employed to detect the expression of PIK3CA, PIK3CB, multidrug resistance-1 (MDR-1), lung cancer resistance protein (LRP), glutathione-S-transferase π (GST-π), and DNA topoisomerase Ⅱ (Topo Ⅱ) in 316 CRC specimens. Patients were followed annually by telephone or at an outpatient clinic.

RESULTS: The overexpression rates of MDR-1, LRP, Topo II, and GST-π in CRC were found to be 72.78%, 70.89%, 77.53%, and 76.58%, respectively. Correlation analysis showed that PIK3CA and PIK3CB expression exhibited a positive correlation with MDR-1, LRP, and GST-π expression (r = 0.288, 0.128, and 0.197, respectively; P<0.05). PIK3CA and PIK3CB expression was correlated with the degree of tumor differentiation and lymph node metastasis (P<0.05). Kaplan-Meier analysis revealed that the 5-year survival rate was significantly correlated with lymph node metastasis, positive expression of PIK3CA and PIK3CB, and negative expression of GST-π and MDR-1. Multivariate analysis revealed that GST-π and MDR-1 expression and lymph node metastasis could serve as independent predictive factors of overall survival.

CONCLUSION: The expression of both PIK3CA and PIK3CB is increased and related to the development and progression of CRC and MDR. The combined detection of PIK3CA and PIK3CB is of great significance for prognostic evaluation and therapy optimization in patients with CRC.

Clinical significance of expression of p85a, nm23 and MMP-2 in primary colorectal cancer and lymph node metastasis

AIM: To detect the expression of p85a, nm23 and matrix metalloproteinase-2 (MMP-2) in primary colorectal cancer and lymph node metastasis, and to discuss the role and significance of p85a, nm23 and MMP-2 in colorectal cancer metastasis.

METHODS: Two hundred and forty-three colorectal cancer patients were divided into two groups: patients with cervical lymph node metastasis and those without. Primary tumor samples from patients without cervical lymph node metastasis (n = 51) and those with lymph node metastasis (n = 192), cervical lymph node metastasis samples (n = 192), and normal colorectal tissue samples from normal controls (n = 243) were collected. Immunohistochemistry was used to detect the expression of p85a, nm23 and MMP-2 in the above samples. The correlations between expression of p85a, nm23 and MMP-2 and clinicopathological and prognostic factors of colorectal cancer were analyzed.

RESULTS: The positive expression rates of p85a and MMP-2 in primary tumor and lymph node metastasis samples from patients with lymph node metastasis were significantly higher than those in primary tumors from patients without cervical lymph node metastasis and normal colorectal tissue samples. The expression of nm23 in the metastasis was significantly lower than those in the other groups. In metastatic cancer, the expression of p85a and nm23 had a negative correlation (P < 0.05), and p85a and MMP-2 had a positive correlation (P < 0.05). According to survival analysis, p85a, nm23 and MMP-2 were independent factors for the prognosis of colorectal cancer. The cases with higher p85a and lower nm23 or with both higher p85a and MMP-2 had shorter lifetime.

CONCLUSION: In the process of colorectal cancer metastasis, p85a can enhance the expression of MMP-2 and restrain the expression of nm23. They all play an important role in colorectal metastasis, and all of them are prognostic factors for colorectal cancer.

Diffuse reflectivity measurement using cubic cavity

A method for measuring diffuse reflectivity using cubic cavity based on the variable port fraction method was developed by measuring oxygen P11 line at 762 nm using tunable diode laser absorption spectroscopy. An experimental method to determine the additional path length l0 was presented. We measured the diffuse reflectivity of a cubic cavity with scattering coatings of different thickness. The error of diffuse reflectivity was reduced from 0.004 to 0.0003 when the diffuse reflectivity increased from 0.867(4) to 0.9887(3). A simulation result manifests that the error of diffuse reflectivity has the potential to be further reduced at higher diffuse reflectivity.

Significance of expression of autophagy related factors beclin1 and mTOR in malignant transformation of colorectal adenoma

AIM: To investigate the significance of expression of autophagy regulatory molecules beclin1 and mTOR in the malignant transformation of colorectal adenoma.

METHODS: Immunohistochemistry was used to detect the expression of beclin1, mTOR and LC3-B in 30 cases of normal colorectal mucosa, 60 cases of low-grade intraepithelial neoplasia (LGIN), 60 cases of high-grade intraepithelial neoplasia (HGIN) and 80 cases of colorectal carcinoma.

RESULTS: The expression of both beclin1 and LC3-B in colorectal cancer was significantly higher than that in LGIN and normal mucosa (P < 0.05), but there was no significant difference in the expression of beclin1 between colorectal cancer and HGIN (P > 0.05). The expression of mTOR in colorectal cancer was significantly higher than that in normal mucosa, LGIN and HGIN (P < 0.05), but no significant difference was found between LGIN and HGIN. In colorectal cancer, the expression of both beclin1 and LC3-B was related to tumor size; the expression of mTOR was associated with tumor size and depth of invasion; the expression of beclin1, mTOR and LC3-B in LGIN and HGIN was not related to clinicopathologic characteristics. There was a positive correlation between the expression of beclin1 and LC3-B in LGIN, HGIN and colorectal carcinoma (r = 0.390, 0.306, 0.443, P < 0.05). The expression of mTOR was not related to that of LC3-B in LGIN, but mTOR expression was positively associated with LC3-B expression in both HGIN and colorectal cancer (r = 0.284, 0.223, P < 0.05).

CONCLUSION: Autophagy may play a critical role in the malignant transformation of colorectal adenoma.

Changed trends of major causes of visual impairment in Sichuan, China from 1987 to 2006

AIM

To study the trends of major causes of visual impairment (VI) in adults in Sichuan, China and evaluate the effect of aging on the trends.

METHODS

We used data from the National Sample Survey on Disabilities (NSSD) in Sichuan province conducted in 1987 and 2006. The age-adjusted prevalence of major causes of VI and the prevalence stratified by age in each cause were calculated and compared. The association between age and each cause of VI was also analyzed.

RESULTS

Retinal disease increased and became the second leading cause of VI in 2006 while blinding trachoma decreased markedly. Cataract and non-trachomatous corneal diseases were among the leading causes of VI in both years. We found associations between age and causes of VI, with age showing the strongest association with cataract and relatively lower associations with other causes.

CONCLUSION

In the last two decades, dramatic changes occurred in the major causes of VI with significantly increased retinal disease and decreased blinding trachoma. Aging of the population might be an important factor accounting for the changed trends of VI. Understanding the prevalence of VI, its major causes and trends over time can assist in prioritizing and developing effective interventional strategies and monitoring their impact.

Association of HLA-B*1502 and *1511 allele with antiepileptic drug-induced Stevens-Johnson syndrome in central China

Previous studies have demonstrated a strong association between carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS) and HLA-B*1502 in Han Chinese. Here, we extended the study of HLA-B*1502 susceptibility to two different antiepileptic drugs, oxcarbazepine (OXC) and phenobarbital (PB). In addition, we genotyped HLA-B*1511 in a case of CBZ-induced SJS with genotype negative for HLA-B*1502. The presence of HLA-B*1502 was determined using polymerase chain reaction with sequence-specific primers (PCR-SSP). Moreover, we genotyped HLA-B*1502 in 17 cases of antiepileptic drugs (AEDs)-induced cutaneous adverse drug reactions (cADRs), in comparison with AEDs-tolerant (n=32) and normal controls (n=38) in the central region of China. The data showed that HLA-B*1502 was positive in 5 of 6 cases of AEDs-induced SJS (4 CBZ, 1 OXC and 1 PB), which was significantly more frequent than AEDs-tolerant (2/32, 18 CBZ, 6 PB and 8 OXC) and normal controls (3/38). Compared with AEDs-tolerant and normal controls, the OR for patients carrying the HLA-B*1502 with AEDs-induced SJS was 6.25 (95% CI: 1.06-36.74) and 4.86 (95% CI: 1.01-23.47). The sensitivity and specificity of HLA-B*1502 for prediction of AEDs-induced SJS were 71.4%. The sensitivity and specificity of HLA-B*1502 for prediction of CBZ-induced SJS were 60% and 94%. HLA-B*1502 was not found in 11 children with maculopapular exanthema (MPE) (n=9) and hypersensitivity syndrome (HSS) (n=2). However, we also found one case of CBZ-induced SJS who was negative for HLA-B*1502 but carried HLA-B*1511. It was suggested that the association between the CBZ-induced SJS and HLA-B*1502 allele in Han Chinese children can extend to other aromatic AEDs including OXC and PB related SJS. HLA-B*1511 may be a risk factor for some patients with CBZ-induced SJS negative for HLA-B*1502.

Hepatitis B virus subgenotype C2- and B2-associated mutation patterns may be responsible for liver cirrhosis and hepatocellular carcinoma, respectively

The objective of this study was to examine hepatitis B virus (HBV) subgenotypes and mutations in enhancer II, basal core promoter, and precore regions of HBV in relation to risks of liver cirrhosis (LC) and hepatocellular carcinoma (HCC) in Southeast China. A case-control study was performed, including chronic hepatitis B (CHB; n=125), LC (n=120), and HCC (n=136). HBV was genotyped by multiplex polymerase chain reaction and subgenotyped by restriction fragment length polymorphism. HBV mutations were measured by DNA sequencing. HBV genotype C (68.2%) predominated and genotype B (30.2%) was the second most common. Of these, C2 (67.5%) was the most prevalent subgenotype, and B2 (30.2%) ranked second. Thirteen mutations with a frequency >5% were detected. Seven mutation patterns (C1653T, G1719T, G1730C, T1753C, A1762T, G1764A, and G1799C) were associated with C2, and four patterns (C1810T, A1846T, G1862T, and G1896A) were associated with B2. Six patterns (C1653T, G1730C, T1753C, A1762T, G1764A, and G1799C) were obviously associated with LC, and 10 patterns (C1653T, G1730C, T1753C, A1762T, G1764A, G1799C, C1810T, A1846T, G1862T, and G1896A) were significantly associated with HCC compared with CHB. Four patterns (C1810T, A1846T, G1862T, and G1896A) were significantly associated with HCC compared with LC. Multivariate regression analyses showed that HBV subgenotype C2 and C2-associated mutation patterns (C1653T, T1753C, A1762T, and G1764A) were independent risk factors for LC when CHB was the control, and that B2-associated mutation patterns (C1810T, A1846T, G1862T, and G1896A) were independent risk factors for HCC when LC was the control.

Expression of PI3Kp110α and PI3Kp110β in colorectal canceration

AIM: To investigate the expression of PI3Kp110α and PI3Kp110β in colorectal canceration and to analyze their correlation.

METHODS: PI3Kp110α and PI3Kp110β expression was detected by immunohistochemistry in 30 cases of normal colorectal mucosa, 46 cases of low-grade intraepithelial neoplasia (LGIN), 32 cases of high-grade intraepithelial neoplasia (HGIN) and 60 cases of colorectal carcinoma.

RESULTS: The expression of PI3Kp110α in colorectal carcinoma was significantly higher than that in normal colorectal mucosa and LGIN (both P < 0.05), but there was no significant difference between colorectal carcinoma and HGIN (P > 0.05). The expression of PI3Kp110β was highest in colorectal carcinoma, followed by HGIN, LGIN and normal colorectal mucosa (P < 0.05). PI3Kp110α expression was correlated with patient age, tumor size and tumor differentiation (all P < 0.05). PI3Kp110β expression was correlated with TNM stage and degree of tumor differentiation (both P < 0.05). The expression of PI3Kp110α was positively correlated with that of PI3Kp110β in LGIN (P < 0.05). There was no significant correlation between the expression of PI3Kp110α and that of PI3Kp110β in colorectal carcinoma, HGIN or normal colorectal mucosa (all P > 0.05).

CONCLUSION: PI3Kp110α and p110β may play different roles in colorectal canceration.

Role of natural day-length and temperature in determination of summer and winter diapause in Pieris melete (Lepidoptera: Pieridae)

Under field conditions, the cabbage butterfly, Pieris melete, displays a pupal summer diapause in response to relatively low daily temperatures and gradually increasing day-length during spring and a pupal winter diapause in response to the progressively shorter day-length. To determine whether photoperiod is 'more' important than temperature in the determination of summer and winter diapause, or vice versa, the effects of naturally changing day-length and temperature on the initiation of summer and winter diapause were systematically investigated under field conditions for five successive years. Field results showed that the incidence of summer diapause significantly declined with the naturally increasing temperature in spring and summer generations. Path coefficient analysis showed that the effect of temperature was much greater than photoperiod in the determination of summer diapause. In autumn, the incidence of diapause was extremely low when larvae developed under gradually shortening day-length and high temperatures. The incidence of winter diapause increased to 60-90% or higher with gradually shortening day-length combined with temperatures between 20.0°C and 22.0°C. Decreasing day-length played a more important role in the determination of winter diapause induction than temperature. The eco-adaptive significance of changing day-length and temperature in the determination of summer and winter diapause was discussed.

Identification of sex-specific polymorphic sequences in the goat amelogenin gene for embryo sexing

Amelogenin (AMEL) is a conserved gene located on the sex chromosomes of mammals. It is involved in the formation of enamel, which is the hard, white material that forms the protective outer layer of each tooth. In this study, we first cloned and determined the intron sequences of the goat AMELX and AMELY genes from female and male ear tissues. The polymorphic AMEL alleles were further analyzed by PCR-based RFLP and Southern blot hybridization analyses. Results showed that intron 5 nucleotide sequences of the goat AMELY gene contains multiple deletions/insertions and shares only 48.5% identity to intron 5 of the goat AMELX gene. Based on the polymorphic AMEL intron sequences, a set of sex-specific triplex primers was designed to PCR amplify a single fragment of 264 bp from the X chromosome of female goats and 2 fragments of 264 and 206 bp from the X and Y chromosomes, respectively, of male goats. An increased sensitivity for sex determination was reached with a single blastomere at the blastula stage isolated from goat embryos. A total of 43 goat embryos were used to estimate a 100% accuracy rate of this method confirmed by chromosomal karyotyping and live births. The embryo sexing technique has been successfully applied in different strains of goats including Alpine, Saanen, Nubian, and Taiwan goats.

Application of high-frequency ultrasound for the detection of surgical anatomy in the rodent abdomen

Rats are used extensively in abdominal disease research. To monitor disease progress in vivo, high-frequency ultrasound (HFU) can be a powerful tool for obtaining high-resolution images of biological tissues. However, there is a paucity of data regarding the correlation between rat anatomy and corresponding HFU images. Twenty-four adult male Sprague-Dawley (SD) rats underwent abdominal scans using HFU (40 MHz) surgical procedures to identify abdominal organs and major vessels as well as in situ scanning to confirm the imaging results. The results were compared with those of human abdominal organs in ultrasonographic scans. The rat liver, paired kidneys, stomach, intestines, and major blood vessels were identified by HFU and the ultrasonic morphologies of the liver and kidneys showed clear differences between rats and humans. Clinically relevant anatomical structures were identified using HFU imaging of the rat abdomen, and these structures were compared with the corresponding structures in humans. Increased knowledge with regard to identifying the anatomy of rat abdominal organs by ultrasound will allow scientists to conduct more detailed intra-abdominal research in rodents.

Development and validation of an improved Bradford method for determination of insulin from chitosan nanoparticulate systems

CONTEXT

Blank chitosan nanoparticles are currently used as reference for the calibration curve, which fails to resolve the supernatant of the nanoparticles in the interference of Coomassie Brilliant Blue G-250 reagent; supernatants are generated at different chitosan nanoparticulate prescriptions, which have different interferences. There are notable errors in the experimental results, and the method is not feasible.

OBJECTIVE

In this study, an improved, rapid, and economic Bradford method was developed and validated.

MATERIALS AND METHODS

The pH of the supernatant of blank chitosan nanoparticles was adjusted to 7-9 through adding saturated NaOH. The precipitation (free chitosan) in the solution was separated by centrifuging for about 10 min (4000 r/min).

RESULTS

The method eliminated the interference of free chitosan of different prescriptions. The results showed that the method presented a linearity in the range of 50-300 microg/mL (R(2) = 0.9992), and possessed a good inter-day and intra-day precision based on relative standard deviation values (less than 3.10%). Recovery of the supernatant of blank chitosan nanoparticles was between 98.30 and 99.93%, and the recovery of blank chitosan nanoparticles was between 95.57 and 100.27%.

DISCUSSION AND CONCLUSION

The method was further tested for determination of the association efficiency of insulin to nanoparticulate carriers composed of chitosan. Encapsulant release under simulated gastrointestinal fluids was evaluated.

Simultaneous detection of multiple-gas species by correlation spectroscopy using a multimode diode laser

Simultaneous detection of multiple-gas species has for the first time (to our knowledge) been demonstrated by using a multimode diode-laser-based correlation spectroscopy (MDL-COSPEC) scheme. Concentration measurements of a mixture of CO(2) and CO gas were performed by probing overlapping line spectra around 1.57microm using an MDL. Species identification and corresponding quantitive analysis were implemented by correlating the recorded absorption signals of the sample gas mixtures with those of the reference gases of particular interest, attaining accuracies of 2% and 1%, respectively. MDL-COSPEC is a generic technique with potential application for simultaneous detection of multiple gases having resolvable narrow lines.

[Screening and application of prokaryotic enhancer-like sequence 3A]

OBJECTIVE

To screen enhancer-like sequences from Escherichia coli strain C600 genome, to construct an expression vector harboring prokaryotic enhancer-like sequence and study the effect of interferon gene expression.

METHODS

Enhancer-like element from Escherichia coli strain C600 genome was obtained by using the chloramphenicol acetyl-transferase (CAT) gene as reporter gene. An expression vector harboring prokaryotic enhancer-like sequence from Escherichia coli strain C600 was constructed. Interferon was expressed and assayed.

RESULTS

An enhancer-like sequences with distance and orientation independence property were screened and named 3A. Quantification test showed that the direct and reverse orientation of 3A could increase the activity of beta-galactosidase with 7.11 and 2.93 times. The enhancing activity of the element was on transcription level. An expression vector harboring the prokaryotic enhancer-like sequence 3P3 which was enhancing function region of sequence 3A was constructed. Using this vector the antiviral activity of interferon alpha-2b was increased by 3.7 times in comparison with the original expression plasmid.

CONCLUSION

3A enhancer-like sequence was screened from Escherichia coli strain C600 genome. Interferon gene was highly expressed by using an expression vector harboring enhancer-like sequences.

The physiological role of pre- and postsynaptic GABA(B) receptors in membrane excitability and synaptic transmission of neurons in the rat's dorsal cortex of the inferior colliculus

In the inferior colliculus (IC), GABAergic inhibition mediated by GABA(A) receptors has been shown to play a significant role in regulating physiological responses, but little is known about the physiological role of GABA(B) receptors in IC neurons. In the present study, we used whole-cell patch clamp recording in vitro to investigate the effects of activation of GABA(B) receptors on membrane excitability and synaptic transmission of neurons in the rat's dorsal cortex of the inferior colliculus (ICD). Repetitive stimulation of GABAergic inputs to ICD neurons at high frequencies could elicit a slow and long-lasting postsynaptic response, which was reversibly abolished by the GABA(B) receptor antagonist, CGP 35348. The results suggest that postsynaptic GABA(B) receptors can directly mediate inhibitory synaptic transmission in ICD. The role of postsynaptic GABA(B) receptors in regulation of membrane excitability was further investigated by application of the GABA(B) receptor agonist, baclofen. Baclofen hyperpolarized the cell, reduced the membrane input resistance and firing rate, increased the threshold for generating action potentials (APs), and decreased the amplitude of the AP and its associated after-hyperpolarization. The Ca2+-mediated rebound depolarization following hyperpolarization and the depolarization hump at the beginning of membrane depolarization were also suppressed by baclofen. In voltage clamp experiments, baclofen induced inward rectifying K+ current and reduced low- and high-threshold Ca2+ currents, which may account for the suppression of membrane excitability by postsynaptic GABA(B) receptors. Application of baclofen also reduced excitatory synaptic responses mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and inhibitory synaptic responses mediated by GABA(A) receptors. Baclofen increased the ratios of 2nd/1st excitatory and inhibitory postsynaptic currents to paired-pulse stimulation of the synaptic inputs. These results suggest that fast glutamatergic and GABAergic synaptic transmission in ICD can be modulated by presynaptic GABA(B) receptors.