[Prospective randomized controlled trial on 2 940 nm fractional erbium laser combined with fractional micro-plasma radiofrequency in the treatment of facial atrophic acne scars]

Objective: To compare the efficacy and safety of 2 940 nm fractional erbium laser combined with fractional micro-plasma radiofrequency (FMR) therapy and 2 940 nm fractional erbium laser in the treatment of atrophic acne scars. Methods: A prospective randomized controlled research was conducted. A total of 100 atrophic acne scar patients (38 males and 62 females, aged 18-37 years) who were treated in the Scar Laser Clinic of the Department of Plastic and Reconstructive Surgery of Shanghai Ninth People's Hospital of Shanghai Jiao Tong University School of Medicine from March 2018 to March 2021 and conformed to the inclusion criteria were recruited. The patients were randomly divided into erbium laser+FMR group and erbium laser alone group, with 50 cases in each group. The facial acne scars of patients in erbium laser alone group were treated with 2 940 nm fractional erbium laser, while the facial acne scars of patients in erbium laser+FMR group were treated with erbium laser as above, besides, the scars of U and M types were treated with FMR, once every 3 months for a total of 3 times. Before the first treatment and 3 months after each treatment, the Echelle D'Assessment Clinique des Cicatrices D'Acne (ECCA) was used to score the scar. The occurrence of adverse reaction during the treatment process was observed and recorded, and the incidence was calculated. Three months after the last treatment, the 5-level classification method was used to evaluate the satisfaction of patients with the treatment effect, and the satisfaction rate was calculated. Data were statistically analyzed with independent sample t test and chi-square test. Results: A total of 89 patients completed the study, including 46 patients in erbium laser+FMR group (19 males and 27 females, aged (26±5) years) and 43 patients in erbium laser alone group (15 males and 28 females, aged (27±6) years). The ECCA scores before the first treatment and 3 months after the first treatment of patients were similar between the two groups (P>0.05). The ECCA scores of patients in erbium laser+FMR group at 3 months after the second and third treatment were 72±23 and 61±18, respectively, which were significantly lower than 85±26 and 76±25 in erbium laser alone group (with t values of -2.45 and -3.26, respectively, P<0.05). During the treatment process, the incidence of adverse reaction of patients in erbium laser+FMR group and erbium laser alone group were 23.91% (11/46) and 16.28% (7/43), respectively, and there was no statistically significant difference between the two groups (P>0.05). The satisfaction rate of patients in erbium laser+FMR group was 78.26% (36/46) at 3 months after the last treatment, which was significantly higher than 53.49% (23/43) in erbium laser alone group (χ2=6.10, P<0.05). Conclusions: The 2 940 nm fractional erbium laser combined with FMR is superior to 2 940 nm fractional erbium laser alone in the treatment of facial atrophic acne scars, achieving significantly higher efficacy without significantly increasing the incidence of adverse reaction, and patients are more satisfied with the efficacy. It can be used as a recommended therapy in clinical practice.

Isobaric Stable Isotope N-Phosphorylation Labeling (iSIPL) for Ultrasensitive Proteome Quantification

Stable isotope chemical labeling methods have been widely used for high-throughput mass spectrometry (MS)-based quantitative proteomics in biological and clinical applications. However, the existing methods are far from meeting the requirements for high sensitivity detection. In the present study, a novel isobaric stable isotope N-phosphorylation labeling (iSIPL) strategy was developed for quantitative proteome analysis. The tryptic peptides were selectively labeled with iSIPL tag to generate the novel reporter ions containing phosphoramidate P-N bond with high intensities under lower collision energies. iSIPL strategy are suitable for peptide sequencing and quantitative analysis with high sensitivity and accuracy even for samples of limited quantity. Furthermore, iSIPL coupled with affinity purification and mass spectrometry was applied to measure the dynamics of cyclin dependent kinase 9 (CDK9) interactomes during transactivation of the HIV-1 provirus. The interaction of CDK9 with PARP13 was found to significantly decrease during Tat-induced activation of HIV-1 gene transcription, suggesting the effectiveness of iSIPL strategy in dynamic analysis of protein-protein interaction in vivo. More than that, the proposed iSIPL strategy would facilitate large-scale accurate quantitative proteomics by increasing multiplexing capability.

[Expression and prognostic value of programmed cell death ligand 1 in patients with locally advanced and non-EGFR-mutated non-small cell lung cancer receiving concurrent chemoradiotherapy]

Objective: To explore the expression of programmed cell death ligand 1 (PD-L1) in patients with locally advanced and non-EGFR-mutated non-small cell lung cancer (LA-NSCLC) undergoing concurrent chemoradiotherapy (cCRT) and its association with clinical outcome of patients. Methods: The basic clinical information of 19 patients with unresectable, non-EGFR mutated LA-NSCLC receiving radical cCRT in Cancer Hospital Chinese Academy of Medical Sciences from January 2016 to December 2017 was retrospectively analyzed. The rabbit monoclonal antibody SP263 was used for immunohistochemical analysis to detect the expression of PD-L1 in LA-NSCLC tissues and the tumor proportion score (TPS) equal to or greater than 1% was defined as PD-L1 positive. The associations between PD-L1 ≥1% and PD-L1 ≥25% with the clinical characteristics and clinical outcome of LA-NSCLC patients were evaluated respectively. Results: Among 19 LA-NSCLC patients, 13 had PD-L1 positive expression, and 4 had PD-L1 expression greater than or equal to 25%. No significant difference was observed between patients with PD-L1 positive and negative expressions regarding the distribution of age, smoking history, pathological classification, and TNM staging (P>0.05). A total of 15 patients could be evaluated for therapeutic effect, including 7 patients with partial response (PR), 7 patients with stable disease (SD), and 1 patient with progressive disease (PD). In the group with PD-L1 expression<1%, 3 patients were in objective response, and 4 patients were in disease control. In the group with PD-L1 expression ≥1%, 4 patients were in objective response, and 10 patients were in disease control. When the PD-L1 expression was less than 25%, 6 patients gained the objective response, and 11 patients gained the disease control. When the PD-L1 expression was greater than or equal to 25%, 1 patient gained the objective response, and 3 patients gained the disease control. The median overall survival (OS) was 35 (95%CI: 12.7-57.3) months for patients with PD-L1 ≥1% and 40 (95%CI: not reaching the end point) months for patients with PD-L1<1% (P=0.284). Patients with PD-L1 ≥25% had a median survival time of 12 (95%CI:0.0-34.5) months, and patients with PD-L1<25% had a median survival time of 40 (95%CI: 27.4-52.6) months (P=0.241). Conclusions: The prognosis of LA-NSCLC patients with PD-L1 positive and no-EGFR mutation receiving concurrent chemoradiation has a trend of poor prognosis. A larger sample size study is warranted to explore the prognostic value of PD-L1 expression in inoperable LA-NSCLC patients and to further explore the effect of immunotherapy on patients with different PD-L1 expression levels.

Qing-Luo-Yin Alleviated Experimental Arthritis in Rats by Disrupting Immune Feedback Between Inflammatory T Cells and Monocytes: Key Evidences from Its Effects on Immune Cell Phenotypes

BACKGROUND

Qing-Luo-Yin (QLY) is an anti-rheumatic herbal formula. Despite the well-investigated therapeutic efficacy of QLY, its immune regulatory properties are largely unknown. CD4+ T cells and monocytes are two key parameters in rheumatoid arthritis (RA). This study investigated the changes in these cells in QLY-treated RA animal models.

MATERIALS AND METHODS

RA models were induced in male SD rats and were orally treated with QLY. Dynamic metabolic changes in collagen-induced arthritis (CIA) rats were monitored by 1H NMR approach. The immunity profiles of CIA and adjuvant-induced arthritis (AIA) rats were evaluated using immunohistochemical, PCR, ELISA, cytokine chip, flow cytometry, and immunofluorescence experiments. The bioactive components in QLY were identified by bioinformatic-guided LC-MS analyses. The compounds with high abundance in QLY decoction and easily absorbed were taken as key anti-rheumatic components and used to treat blood-derived immune cells using in vitro experiments.

RESULTS

The results indicated that QLY decreased Th17 cells frequency and T cells-released IL-6, IL-17 and GM-CSF in CIA rats, which was attributed to the impaired lymphocyte maturation and altered differentiation. QLY inhibited lactic acid production and inflammatory polarization in the monocytes during the peak period of AIA and CIA. AIA monocytes elicited significant increase in Th17 cells counts, IL-6 and IL-1β secretion in co-cultured splenocytes, which was abrogated by QLY. QLY-containing serum suppressed the phosphorylation of JNK and p65 in AIA lymphocyte-stimulated normal monocytes and consequently inhibited iNOS and IL-1β expression as well as IL-6 and IL-1β production. Matrine, sinomenine and sophocarpine were identified as major bioactive compounds in QLY. These identified compounds effectively inhibited the development of inflammatory T cells using concentrations detected in QLY-treated rats. At higher concentrations (20-fold increase), the chemical stimuli significantly suppressed the production of IL-1β in AIA monocytes by inhibiting JNK and p65 pathways.

CONCLUSION

By targeting inflammatory T cells and monocytes as well as disrupting their interplay, QLY improved immune environment in RA models especially during the active stages of disease.

Effect of dietary taurine supplementation on metabolome variation in plasma of Nile tilapia

Taurine has been considered as an essential nutrient for many aquaculture species. While dietary taurine supplementation is highly recommended, novelty studies on taurine metabolism in fish are needed. The present study aimed to provide insight into the molecular mechanisms involved in multiple metabolome changes in Nile tilapia (Oreochromis niloticus) by studying plasma metabolic profile changes in response to graded levels of dietary taurine supplementation. The analysis used proton nuclear magnetic resonance-based metabolomics. Four groups of tilapias were fed with four diets supplemented with 0.0, 0.4, 0.8 and 1.2% taurine for 84 days. Fish plasma was sampled at multiple time points to provide an accurate snapshot of specific metabolic profiles during growth. Under the effect of taurine supplementation, 21 and 12 metabolites in tilapia plasma shown significant changes in terms of time-dependence and diet-dependence, respectively. These metabolic changes in tilapia plasma were mainly associated with energy and amino acid metabolism, lipids, nucleotides and protein metabolism. The results indicate that 0.8% taurine supplementation could significantly improve the carbohydrate synthesis, protein digestion and absorption, and fat deposition of tilapia and thereby promoted growth and development of tilapia.

Alcohol Consumption and Risk of Gastric Cancer: The Japan Collaborative Cohort Study

BACKGROUND

Alcohol consumption is a potential risk factor for gastric cancer. However, findings from cohort studies that examined the relationship between alcohol consumption and gastric cancer risk among Japanese population are not conclusive.

METHODS

A total of 54,682 Japanese men and women participating in the Japan Collaborative Cohort study completed a questionnaire, including alcohol consumption information. The Cox proportional hazard model was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

After a median 13.4-year follow-up, we documented 801 men and 466 women incident cases of gastric cancer. Alcohol consumption was associated with increased risk of gastric cancer among men (HRs in ex-drinkers and current alcohol consumption of <23 g, 23-<46 g, 46-<69 g, and ≥69 g/d categories versus never drinkers were 1.82; 95% CI, 1.38-2.42, 1.41; 95% CI, 1.10-1.80, 1.47; 95% CI, 1.17-1.85, 1.88; 95% CI, 1.48-2.38, and 1.85; 95% CI, 1.35-2.53, respectively, and that for 10 g increment of alcohol consumption after excluding ex-drinkers was 1.07; 95% CI, 1.04-1.10). The association in men was observed for cardia and non-cardia gastric cancer (HRs in the highest alcohol consumption category versus never drinkers were 9.96; 95% CI, 2.22-44.67 for cardia cancer and 2.40; 95% CI, 1.64-3.52 for non-cardia cancer). However, no such trend was observed in women.

CONCLUSIONS

Alcohol consumption is associated with increased risk of gastric cancer among Japanese men, regardless of anatomical subsite of the cancer.

[Preliminary evaluation and mechanism of adipose-derived stem cell transplantation from allogenic diabetic rats in the treatment of diabetic rat wounds]

Objective: To investigate whether adipose-derived stem cells (ASCs) from allogeneic diabetic rats can promote wound healing in diabetic rats or not and the mechanism. Methods: (1) Fifty-six male Wistar rats aged 12-16 weeks were divided into diabetic group and healthy group according to the random number table (the same grouping method below), with 28 rats in each group. Rats in healthy group were not treated with any treatment. Rats in diabetic group were injected with 10 g/L streptozotocin 60 mg/kg intraperitoneally in one time to establish the diabetic model. Four rats in diabetic group and 4 rats in healthy group were selected according to the random number table, and the adipose tissue in the inguinal region was taken to culture and purify ASCs, so as to obtain healthy rat-derived ASCs (hereinafter referred to as nASCs) and diabetic rat-derived ASCs (hereinafter referred to as dASCs). The third passage of nASCs (n=3) and dASCs (n=3) were taken, and the positive expression rates of cell surface differentiation antigens CD105, CD31, CD34, and CD44 were detected with flow cytometer for defining ASCs purity. (2) The rest 24 rats in healthy group and 24 rats in diabetic group were used to make three round full-thickness skin defect wounds with a diameter of 12 mm on the back of each rat. Immediately after injury, phosphate buffer saline (PBS), nASCs of 2×10(7)/mL, and dASCs of 2×10(7)/mL each in the volume of 0.5 mL were subcutaneously injected into three wounds and their margins of each rat, respectively. On post injury day (PID) 1, 3, 7, and 12, 6 rats in each group were selected according to the random number table to calculate the wound area, and the wound tissue was stained with hematoxylin-eosin to observe the histological morphology of the wound. (3) Human ASCs (hASCs) were subcultured, and the 4th to 7th passage of cells were used for the subsequent experiments. The hASCs were divided into 7 groups, with 12 samples in each group. Cells in blank control group were cultured with mesenchymal stem cell culture medium, and cells in simple advanced glycation end products (AGEs) group, simple protein group, simple high glucose group, simple high osmotic pressure group, AGEs-high glucose combination group, and protein-high osmotic pressure combination group were cultured with mesenchymal stem cell culture medium containing a final mass concentration of 100 mg/L AGEs, 100 mg/L bovine serum albumin (BSA), 28 mmol/L D-glucose, 28 mmol/L mannitol, 100 mg/L AGEs+ 28 mmol/L D-glucose, 100 mg/L BSA+ 28 mmol/L mannitol, respectively. Cell proliferation was detected by cell counting kit 8 at post culture hour (PCH) 2 and on post culture day (PCD) 2, 4 and 6. (4) The hASCs were divided into blank control group, simple AGE group, simple high glucose group, and AGE-high glucose combination group, with 12 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 0, 2, 4, and 6, the positive expression rates of cell surface differentiation antigens CD105, CD44, and CD45 were detected by flow cytometer to estimate their homeostasis. (5) The hASCs were divided into AGE-high glucose combination group and protein-high osmotic pressure combination group, with 9 samples in each group, which were treated the same as corresponding groups in experiment (3). On PCD 2, 4, and 6, the expression of intracellular protein was detected by cyanine 3-streptavidin double-antibody sandwich technique. Data were processed with analysis of variance for factorial design, least significant difference test, and Bonferroni correction. Results: (1) The positive expression rates of CD44 in nASCs and dASCs were both higher than 96%, the positive expression rates of CD31 and CD34 were low, and the positive expression rates of CD105 were about 40%, which basically met the purity requirements. (2) The areas of wounds treated by three methods in rats of healthy group and diabetic group were similar on PID 1 (P>0.05). In healthy group, compared with (0.682 1±0.078 9), (0.314 3±0.113 7), and (0.064 3±0.002 1) cm(2) of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.464 1±0.092 6), (0.223 9±0.072 7), and (0.034 3±0.012 5) cm(2), P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 and 12 [(0.514 1±0.124 1) and (0.043 7±0.032 8) cm(2), P<0.05] but was not obviously changed on PID 7 [(0.274 2±0.062 5) cm(2), P>0.05]. Compared with those of the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in healthy group decreased significantly on PID 3 and 7 (P<0.05) but was not obviously changed on PID 12 (P>0.05). In diabetic group, compared with (0.853 5±0.204 8), (0.670 5±0.164 8), and (0.131 4±0.074 4) cm(2) of the PBS-treated wounds in rats, the area of nASCs-treated wounds in rats decreased significantly on PID 3, 7, and 12 [(0.633 4±0.132 5), (0.331 8±0.023 5), and (0.074 2±0.003 8) cm(2), P<0.05], the area of dASCs-treated wounds in rats decreased significantly on PID 3 [(0.773 6±0.182 2) cm(2), P<0.05] but was not obviously changed on PID 7 and 12 [(0.510 6±0.192 2) and (0.114 4±0.003 1) cm(2), P>0.05]. Compared with the dASCs-treated wounds of rats within the same group, the area of the nASCs-treated wounds of rats in diabetic group was not obviously changed on PID 3 and 7 (P>0.05) but decreased significantly on PID 12 (P<0.05). There was no obvious difference in histological morphology of the wounds treated with three methods in rats of each group on PID 1. On PID 3, a small amount of microvessels were formed in the wounds treated with nASCs and dASCs of rats in both groups, but microvessel formation was almost undetected in the PBS-treated wounds. On PID 7, more small blood vessels and fibroblasts (Fbs) were observed in the wounds treated with nASCs and dASCs of rats in both groups, but the small blood vessels and Fbs were slightly less in the PBS-treated wounds. On PID 12, the wounds treated with nASCs and dASCs of rats in the two groups were covered by epithelial tissue, the granulation tissue in the PBS-treated wounds of rats in healthy group was not obvious, and the PBS-treated wounds of rats in diabetic group were not completely epithelialized. (3) Compared with those of blank control group, the cell number of hASCs in simple AGEs group decreased significantly on PCD 2, 4, and 6 (P<0.05), which increased significantly on PCD 2 and 4 in simple high glucose group (P<0.05), and that in AGEs-high glucose combination group decreased significantly on PCD 4 and 6 (P<0.05). (4) Compared with that on PCD 4 within the same group, the positive expression rate of CD105 in hASCs decreased significantly in blank control group, simple AGEs group, and AGEs-high glucose combination group on PCD 6 (P<0.05). The positive expression rate of CD44 was higher than 95%, and that of CD45 was less than 2% in hASCs of each group at each time point. (5) Detection values of 7 proteins were located in the confidence interval. The expression levels of basic fibroblast growth factor and tissue inhibitor of metalloproteinase-1 in hASCs of AGEs-high glucose combination group and protein-high osmotic pressure combination group showed increasing trend with the prolongation of culture time. The expression level of human monocyte chemoattractant protein 1 (MCP-1) in hASCs of AGEs-high glucose combination group showed increasing trend with the prolongation of culture time, while the expression level of growth-regulated oncogene (GRO) on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05); the expression levels of MCP-1 and GRO in hASCs of protein-high osmotic pressure combination group showed decreasing trend with the prolongation of culture time. The expression level of follistatin in hASCs of protein-high osmotic pressure combination group decreased obviously on PCD 4, while that in hASCs of AGEs-high glucose combination group was significantly lower on PCD 6 than that on PCD 4 (P<0.05). The expression level of vascular endothelial growth factor (VEGF) in hASCs of protein-high osmotic pressure combination group decreased gradually with the prolongation of culture time, while that in hASCs of AGEs-high glucose combination group on PCD 4 decreased significantly as compared with that on PCD 2 (P<0.05). The expression level of urokinase-type plasminogen activator receptor in hASCs of protein-high osmotic pressure combination group on PCD 6 was significantly higher than that on PCD 4 within the same group (P<0.05) and that of AGEs-high glucose combination group on PCD 6 (P<0.05). Conclusions: Both nASCs and dASCs can promote wound healing in rats with simple defect injury, but dASCs have no significant effect on wound healing in rats with diabetes mellitus, which may be related to the inhibition of ASCs proliferation and the influence of high glucose and AGEs intervention on their homeostasis and secretory function.

[Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China]

The correct thoughts and principles of diagnosis and treatment of chronic refractory wounds need to be formulated. Through the relevant domestic and international consensus and based on clinical experience, the Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China is proposed. It is considered that in the diagnosis and treatment of chronic refractory wounds, in the case of fully understanding the patient's medical history, the following thoughts and principles should be complied in order. (1) Pay attention to the cleanliness of the wound after being cleaned. (2) Reasonably perform debridement to avoid being " excessive" or " not thorough". (3) Reasonably perform examination, diagnosis, and differential diagnosis of pathogenic factors. (4) Treat according to etiology. (5) Find comorbidities and prevent adverse outcomes. (6) Select the correct wound treatment method reasonably and timely. When the conservative wound care treatment is considered, pay attention to embodying the concept of etiological treatment, treat the wound according to the principles of safety, phase, selectivity, and effectiveness, and make a reasonable choice of continuing conservative treatment or surgical treatment in time after completing the preparation of the wound bed. When surgical treatment is considered, pay attention to the selection of reasonable surgical method and donor site, pay attention to the healing rate of surgical wound site and the outcome of donor site, and give reasonable protection to the wound site after surgery. (7) Carry out rehabilitation treatment after wound healing and related health education.

Diagnostic value of transvaginal four-dimensional hysterosalpingo-contrast sonography combined with recanalization in patients with tubal infertility

Background

A retrospective study was designed to evaluate the diagnostic value of transvaginal four-dimensional hysterosalpingo-contrast sonography (TVS 4D-HyCoSy) combined with recanalization versus laparoscopy for patients with tubal infertility.

Materials and Methods

A total of 195 patients undergoing TVS 4D-HyCoSy were analyzed retrospectively. Of these, 72 patients underwent laparoscopy, which was the gold standard. The endpoints were coincidence rate (defined as a parameter consistent with results arising from TVS 4D-HyCoSy and laparoscopic examination using dye), sensitivity, specificity, positive predictive value, negative predictive value, and Youden index for TVS 4D-HyCoSy.

Results

A total of 385 fallopian tubes were assessed by TVS 4D-HyCoSy, of which 147 (38.2%) were tubal patency, 178 (46.2%) as partial tubal obstruction, and 60 (15.6%) as complete tubal obstruction. Of 195 patients, 72 patients with 144 fallopian tubes underwent laparoscopy and a total coincidence rate of 90.97% compared with TVS 4D-HyCoSy. The sensitivity, specificity, positive predictive value, negative predictive value, and Youden index for 4D-HyCoSy versus laparoscopy were 97.7%, 86.7%, 98.4%, 81.3%, and 0.84, respectively.

Conclusions

TVS 4D-HyCoSy represents a highly useful method for diagnosing tubal patency. However, further large-scale studies are warranted to investigate our findings in patients with tubal infertility.

[Application value of endoscope in probing chronic wound with sinus tract in clinic]

Objective: To explore the application value of endoscope in probing the chronic wound with sinus tract in clinic. Methods: Twenty-eight chronic wounds with sinus tracts from 27 patients conforming to the inclusion criteria admitted to Outpatient Department of Wound Healing Center of Ruijin Hospital from December 2017 to March 2018 were investigated in a prospective and self-controlled trial. After being cleaned, the diameter of the opening of sinus tract was measured with a rule. A probe was used to measure the depth of a sinus tract according to the touch from the probe extremity in operation, and to measure the depth of a sinus tract that could be observed with naked eyes with the help of a pair of hemostatic forceps. Five minutes later, a probe was inserted deeply into the sinus tract to measure the depth under the endoscopic view combined with touch from the probe extremity in operation. Afterwards, the sinus tract was observed with endoscope, and the depth of the tract which could be observed under the endoscopic view was measured using a probe inserted deeply into the sinus tract. After completion of the above exploration, the sinus tract was infused with contrast agent Omnipaque 350 and scanned by computed tomography (CT) later to obtain its depth. The following indicators were calculated: the ratio of the depth of the sinus tract measured by CT to the diameter of the opening of the sinus tract (hereinafter referred to as the depth/diameter ratio of the sinus tract), the deviation rate comparing the depth of the sinus tract measured by conventional method (measured by probe only) and by endoscope (measured by probe under the endoscope view) with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the measured depth of the sinus tract), the deviation rate comparing the depth of the sinus tract that could be observed measured by conventional method and by endoscope with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the depth of the sinus tract that could be observed). Data were processed with paired t test. Pearson correlation analysis was applied to analyze the correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope. Results: The depth/diameter ratio of the sinus tract of this group of wounds was 1-32 (8±7). The deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method were (19±14)% and (79±18)%, respectively, both obviously larger than (9±9)% and (25±25)% by endoscope (t=3.837, 13.626, P<0.01). Positive correlation existed between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by conventional method, and between the depth/diameter ratio of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope (r=0.514, 0.585, 0.651, P<0.01). However, there was no obvious correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by endoscope (r=0.113, P>0.05). Conclusions: Compared with the conventional method, application of endoscope is able to get more accurate data of chronic wounds with sinus tracts and observe the wounds with wider range.

[Distributed lag effects on the relationship between daily mean temperature and the incidence of bacillary dysentery in Lanzhou city]

OBJECTIVE

To discuss the lag effects of daily average temperature on the daily cases of bacillary dysentery in Lanzhou city.

METHODS

The data of daily cases of bacillary dysentery were collected during 2008 and 2015 in the city, and the meteorological data at the same period was integrated. The distributed lag non-linear model was used to analyze the relevance between daily average temperature and the daily cases of bacillary dysentery.

RESULTS

The exposure response relationship between the daily temperature and the incidence of bacillary dysentery was "J" type, the lowest incidence temperature was 17 °C, and the effect of high temperature on different gender and age groups was higher than that of the intermediate effect. The effect of high temperature and intermediate effect on the male and female groups showed an acute effect, the effect of the day was the highest, followed by fluctuations in temperature, and the greater the impact on women. In different age groups, high temperature effect and the intermediate effect of bacterial dysentery in 0-3 years old groups were the biggest; the effects of high and intermediate temperature on people aged 0-3 and 19-64 year all showed acute effects, which were the maximum value at the day, then decreased volatility; and for people aged over 65 years, the day after the onset, decreases and then increases slowly. There were obviously increasing risks of bacillary dysentery both the high temperature (32 °C) and the middle temperature (26 °C) with respect to 17 °C. The accumulative effects were highest at lag14 days, and the RR (95%CI) values of middle temperature was 2.30 (1.53-3.13), 2.45 (1.65-3.30), 2.41 (1.59-3.28), 2.54 (1.40-3.79), 1.82 (0.41-3.43), 1.98 (1.11-2.93), and 1.73 (0.68-2.88) among the males, females, 0-3 years old, 4-11 years old, 12-18 years old, 19-64 years old and over 65 years old people, respectively; while the high temperature was 2.93 (1.38-4.69), 3.08 (1.48- 4.90), 3.26 (1.60-5.16), 3.12 (1.06-5.56), 1.94 (0.73-5.39), 2.31 (0.54-4.36), and 2.06 (0.02-4.51), respectively.

CONCLUSION

The high temperature may increase risks of bacillary dysentery, and the females and younger people were the sensitive population. Meteorological factors play an important role in the occurrence and development of bacillary dysentery in Lanzhou. The incidence of bacillary dysentery is affected by multiple meteorological factors, but the primary one is high temperature. The temperature has not a direct effect on the incidence of bacillary dysentery, but an indirect influence in different populations through the impacts of various aspects of the incidence of bacterial dysentery (residents living habits, communication channels and the habits of the susceptible population).

[Clinical effects of a combination treatment with narrow-spectrum intense pulsed light and fractional carbon dioxide laser on hypertrophic scar pruritus]

Objective: To observe the effects of a combination treatment with narrow-spectrum intense pulsed light and fractional carbon dioxide laser on hypertrophic scar pruritus in clinic. Methods: A prospective randomized controlled study was conducted. A total of 90 patients with hypertrophic scars conforming to the inclusion criteria who were hospitalized in our ward from March to December 2017 were divided into combination treatment group and control group according to the random number table, with 45 patients in each group. For scar pruritus, patients in control group were treated twice by narrow-spectrum intense pulsed light with a one-month interval, while patients in combination treatment group were firstly treated by narrow-spectrum intense pulsed light combined with fractional carbon dioxide laser once, and with narrow-spectrum intense pulsed light once one month later. Before and 3 months after treatment, scar pruritus was evaluated by the Visual Analogue Scale and the Four-item Itch Questionnaire, and the improvement of scar was assessed by photography. Three months after treatment, the treatment satisfaction of scar pruritus was self-rated by patients. Meanwhile, adverse effects were recorded during the procedures and follow-up periods. Data were processed with Chi-square test, paired t test, Wilcoxon rank-sum test, and Fisher's exact probability test. Results: Before treatment, there was no statistically significant difference in scar pruritus degree evaluated by the Visual Analogue Scale and score distribution of scar pruritus location, extent, frequency, and sleep effect of the Four-item Itch Questionnaire between patients of two groups (Z=-1.08, -0.91, -0.03, -0.69, -1.49, P>0.05). Three months after treatment, there was reducing degree of scar pruritus of patients evaluated by the Visual Analogue Scale in control group or combination treatment group compared with before treatment within the same group (Z=-1.98, -4.65, P<0.05 or P<0.01), while the latter was more obvious than the former (Z=-2.14, P<0.05). There were reducing scores of scar pruritus extent and frequency of patients in control group, along with location, extent, frequency, and sleep effect of patients in combination treatment group compared with those before treatment within the same group (Z=-2.33, -2.34, -3.53, -4.96, -3.32, -4.84, P<0.05 or P<0.01). However, scores of scar pruritus location and sleep effect of patients in control group were similar to those before treatment within the same group (Z=-0.58, -1.34, P>0.05). The scores of scar pruritus location, extent, frequency, and sleep effect of patients were obviously lower in combination treatment group compared with control group (Z=-2.09, -2.69, -1.99, -2.23, P<0.05 or P<0.01). It was much better of scar improvement of patients in combination treatment group compared with control group (Z=-4.00, P<0.01). The percentages of treatment satisfaction of scar pruritus of patients with 0, 1%-25%, 26%-50%, 51%-75%, 76%-100% were 0, 2.2% (1/45), 17.8% (8/45), 48.9% (22/45), and 31.1% (14/45) respectively in combination treatment group, which were obviously better than 0, 11.1% (5/45), 53.3% (24/45), 28.9% (13/45), and 6.7% (3/45) in control group (Z=-4.42, P<0.01). During the treatment and follow-up periods, the adverse effect ratio of patients in control group was 6.7% (3/45), similar to 2.2% (1/45) of combination treatment group (P>0.05). Conclusions: The combination of narrow-spectrum intense pulsed light and fractional carbon dioxide laser can greatly reduce pruritus, improve effect of scar treatment, and bring higher patient satisfaction compared with narrow-spectrum intense pulsed light alone in treating hypertrophic scar pruritus. Clinical trial registration: Chinese Clinical Trial Registry, ChiCTR-ONH-17012350.

[Advances in the research of techniques for traumatic scars intervention with photoelectric acoustic therapy]

Traumatic scar is a common complication of skin injury, such as burn, trauma, and surgery. The mechanism for scar formation still remains unclear. Traumatic scar has a negative impact on the quality of patients' life, due to the appearance of scar always causes physical or/and psychological problems to patients. The treatments for scar include surgery, chemotherapy, radiotherapy, and pressure, depending on the kind of scar present. Recently, a great progress in treating scar has been achieved by novel techniques with laser, intense pulsed light, micro-plasma radiofrequency, and ultrasound. The aim of this review is introducing the advances of these techniques for traumatic scars intervention.

[Effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts]

Objective: To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts. Methods: A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test. Results: (1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01). Conclusions: Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

Metabolites from the co-culture of nigranoic acid and Umbelopsis dimorpha SWUKD3.1410, an endophytic fungus from Kadsura angustifolia

The ability of the endophytic fungus Umbelopsis dimorpha SWUKD3.1410 to transform the triterpene nigranoic acid (3, 4-secocycloarta-4(28), 24-(Z)-diene-3, 26-dioic acid; 1) was investigated. Co-culture of nigranoic acid with U. dimorpha SWUKD3.1410 yielded six major products, including a new triterpene (2) and 5 known compounds (3-7). Their structures were identified by the extensive 1D, 2D NMR and HR-ESI-MS Data analysis, and by comparison with those reported data. Among them, 2-4 were transformed from nigranoic acid (1), while 5-7 were derived from the culture medium stimulated by the substrate. On the basis of the structures of 2-4, it was proposed that the transformative process probably involved isomerase and hydroxylase, in which the former was rare in fungi. Additionally, all the compounds (1-7) were evaluated for their cytotoxic activity. As a result, compounds 1, 3-5 exhibited weak cytotoxicity against the tested cell lines, while others showed no cytotoxicity.

[Effects of severe hypoxia and low concentration of serum protein on the function of human hypertrophic scar fibroblasts]

Objective: To simulate the environmental factors during the process of formation and evolution of hypertrophic scar, so as to explore the effects of moderate and severe hypoxia and low concentration of serum protein on the function of human hypertrophic scar fibroblasts (HSFs). Methods: Human HSFs were routinely cultured. Cells of the 3rd to the 6th passage were divided into 10.0% oxygen+ 10.0% fetal calf serum (FCS), 5.0% oxygen+ 5.0% FCS, and 0.5% oxygen+ 0.5% FCS groups according to the random number table. After being cultured with DMEM nutrient solution with no FCS for 24 h, the cells were cultured with the corresponding volume fraction of oxygen and FCS. Cell proliferation activity was determined with methyl-thiazole-tetrazolium assay (denoted as actual cell number). Content of total collagen was detected with Sirius red staining method (denoted as absorbance value). Protein expression levels of hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF), transforming growth factor β₁ (TGF-β₁), B-cell lymphoma 2 (Bcl-2), and P53 were determined with Western blotting (denoted as ratio of gray value). Cell apoptosis rate was detected by in situ end labeling method. The sample numbers of each group in the above experiments were all 3. Data were processed with Kruskal-Wallis test and Dunnett test. Results: (1) Compared with 11 000±1 306 in 10.0% oxygen+ 10.0% FCS group, the cell proliferation activity was higher in 5.0% oxygen+ 5.0% FCS group (13 290±1 500, P<0.05), but lower in 0.5% oxygen+ 0.5% FCS group (6 999±765, P<0.05). (2) Compared with 0.039 6±0.004 2 in 10.0% oxygen+ 10.0% FCS group, the content of total collagen of cells was higher in 5.0% oxygen+ 5.0% FCS group (0.051 6±0.005 1, P<0.05), but lower in 0.5% oxygen+ 0.5% FCS group (0.015 6±0.002 4, P<0.05). (3) Compared with those in 10.0% oxygen+ 10.0% FCS group, the protein expression levels of HIF-1α, VEGF, TGF-β₁, and Bcl-2 were increased (with P values below 0.05), with no obvious difference in protein expression level of P53 in 5.0% oxygen+ 5.0% FCS group (P>0.05), whereas the protein expression levels of HIF-1α, VEGF, TGF-β₁, and Bcl-2 were decreased (with P values below 0.05), while the protein expression level of P53 was increased in 0.5% oxygen+ 0.5% FCS group (P<0.05). (4) Compared with (1.2±0.9)% in 10.0% oxygen+ 10.0% FCS group, the cell apoptosis rate in 5.0% oxygen+ 5.0% FCS group showed no significant difference [(2.6±0.9)%, P>0.05], while it was significantly increased in 0.5% oxygen+ 0.5% FCS group [(13.3±4.1)%, P<0.05]. Conclusions: Severe hypoxia and low concentration of serum protein can inhibit proliferation activity and production of total collagen of human HSFs and induce their apoptosis.

[A novel metabolomic data scaling method based on K-L divergence]

A new scaling method in the current study based on Kullback-Leibler (K-L) divergence is proposed for NMR metabolomic data. The proposed method (called K-L scaling) is a supervised scaling method as group information is incorporated in the scaling procedure. Notably, K-L divergence measures the difference between two different datasets by their probability distributions, it can be used for the analysis of data that either follows Gaussian or non-Gaussian distributions. In K-L scaling, all variables were first standardized to unit variance, then their variance was adjusted using Kullback-Leibler divergence to highlight the significant variables. K-L scaling can tell effectively the difference in spectral data points between two experimental groups, and then enhances the weights of biological-relevant variables, and at the same time reduces the weight of noise and uninformative variables. The developed method was applied to a H-NMR metabolomic dataset acquired from human urine. Analysis results of the dataset showed that this new scaling method is efficient in suppressing the contribution of noise in the resulting multivariate model In addition, it can increase the weights of important variables, and improve the interpretability and predictability of subsequent principal component regression (PCR) and partial least squares discriminant analysis (PLS-DA). Furthermore, the scaling method facilitated the identification of metabolic signatures. The current result suggested that the developed K-L scaling method may become a useful alternative for the preprocessing of NMR-based metabolomic data.

Routine and dynamic MR imaging study of lobular capillary hemangioma of the nasal cavity with comparison to inverting papilloma

BACKGROUND AND PURPOSE

Lobular capillary hemangioma is an uncommon lesion, and its MR imaging appearance has not been fully characterized. The purpose of this study was to determine the MR imaging features of nasal lobular capillary hemangioma and contrast its imaging characteristics to inverting papilloma.

MATERIALS AND METHODS

The MR imaging signals of 32 patients with histopathologically proven nasal lobular capillary hemangiomas and 53 patients with nasal inverted papillomas were retrospectively studied. The findings of dynamic contrast-enhanced MR imaging in 24 lobular capillary hemangiomas and in 53 inverted papillomas were also analyzed. The Monte Carlo exact test was used for comparison of the time-intensity curve patterns of lobular capillary hemangioma and inverted papilloma.

RESULTS

All lobular capillary hemangiomas appeared to be homogeneously isointense to gray matter on T1-weighted images. On T2-weighted images, all lesions showed heterogeneous hyperintensity, and a thin peripheral isointense or hypointense ring was seen in 28 patients. All lesions showed marked enhancement on enhanced images, with the exception of enhancement of the T2 isointense or hypointense ring. Forty-three (81.1%) inverted papillomas had moderate heterogeneous T2 signal intensity, and a characteristic "cerebriform" appearance was detected in 45 (84.91%) of 53 inverted papillomas. The time-intensity curves showed a washout pattern in 18 and a plateau pattern in 6 patients, whereas inverted papillomas showed a washout pattern in 12, a plateau pattern in 35, and a persistent pattern in 6 patients. There was a statistically significant difference as to time-intensity curve pattern between the 2 groups (P < .05).

CONCLUSIONS

Hyperintensity on T2-weighted images, marked enhancement of tumor with a nonenhancing thin peripheral ring, and a washout time-intensity curve pattern are characteristic MR imaging features of nasal lobular capillary hemangiomas.

Solitary fibrous tumor of the sinonasal cavity: CT and MR imaging findings

SUMMARY

SFT is a rare lesion of the sinonasal cavity. We retrospectively reviewed 5 patients with histopathologically proved sinonasal SFTs to determine their CT and MR imaging features. All patients underwent paranasal sinus CT and MR imaging. Four SFTs occurred in the nasal cavity, and 1, in the maxillary sinus. All SFTs had well-defined margins, and the mean maximum diameter was 55 mm. On nonenhanced CT, 5 SFTs appeared homogeneously isoattenuating to gray matter. The most common manifestations of bony involvement were bony remodeling and thinning. On MR imaging, 5 SFTs were isointense to gray matter on T1-weighted images, and the lesions were isointense in 3 and hypointense in 2 patients on T2-weighted images. The lesions showed heterogeneously marked enhancement on postenhanced MR images. Four patients underwent dynamic contrast-enhanced MR imaging, and the TICs showed a washout pattern. A familiarity with the imaging findings of sinonasal SFT may help to diagnose this entity.

Combined therapeutic use of AdGFPFasL and small molecule inhibitors of ceramide metabolism in prostate and head and neck cancers: a status report

As of January 2005, there were 1020 gene therapy clinical trials ongoing worldwide with 675 or 66.2% devoted to cancer gene therapy. The majority are occurring in the US and Europe (http://www.wiley.co.uk/genetherapy/clinical/). At the present time, to our knowledge there are no trials that employ gene delivery of Fas Ligand (FasL). As an important note, and in contrast to somatic cell therapy trials, there are no reported deaths due to therapeutic vector administration in any cancer gene therapy trial. That said, from our studies and from the published literature, the issue of gene delivery remains the major obstacle to successfully employing gene therapy for cancer treatment. Numerous laboratories are studying this with many different approaches. My co-workers and I have focused on the delivery issue by using various approaches that address tumor targeting and transgene expression. In addition, we are focusing on enhancing tumor cell killing via the bystander effect and through use of small molecules to enhance bystander activity.

Highly specific transgene expression mediated by a complex adenovirus vector incorporating a prostate-specific amplification feedback loop

Development of novel therapeutic agents is needed to address the problems of locally recurrent, metastatic, and advanced hormone-refractory prostate cancer. We have constructed a novel complex adenovirus (Ad) vector regulation system that incorporates both the prostate-specific ARR2PB promoter and a positive feedback loop using the TRE promoter to enhance gene expression. This regulation strategy involves the incorporation of the TRE upstream of the prostate-specific ARR2PB promoter to enhance its activity with Tet regulation. The expressions of both GFP and tTA were placed under the control of these TRE-ARR2PB promoters, so that in the cells of prostate origin a positive feedback loop would be generated. This design greatly enhanced GFP reporter expression in prostate cancer cells, while retaining tight control of expression in nonprostate cancer cells, even at an MOI as high as 1000. This novel positive feedback loop with prostate specificity (PFLPS) regulation system we have developed may have broad applications for expressing not only high levels of toxic proteins in cancer cells, but alternatively could also be manipulated to regulate essential genes in a highly efficient conditionally replicative adenovirus vector specifically directed to prostate cancer cells. The PFLPS regulation system, therefore, serves as a promising new approach in the development of both a specific and effective vector for cancer gene therapy.

The 72-kilodalton IE-1 protein of human cytomegalovirus (HCMV) is a potent inducer of connective tissue growth factor (CTGF) in human dermal fibroblasts

Latent human cytomegalovirus (HCMV) infection has been implicated in diseases characterized by tissue remodeling. Because of recent evidence indicating the possibility of a partial HCMV reactivation, the purpose of this study was to examine the role of the HCMV immediate early (IE) genes in the regulation of extracellular matrix (ECM) related host genes. Adenoviral vector expressing IE1 was generated to allow efficient gene delivery into human fibroblasts. IE1 stimulated the prolonged expression of connective tissue growth factor (CTGF) and TIMP1. IE1-dependent stimulation of CTGF was partially mediated by TGF-beta. Moreover, whereas collagenous proteins and collagen type 1 mRNA were only transiently induced by IE1 in the majority of fibroblasts, in selected fibroblast strains IE1 induced persistent ECM upregulation for up to 120 hours. This study suggests that transient or limited HCMV reactivation may play a direct role in abnormal matrix remodeling in GVHD, scleroderma, atherosclerosis and other HCMV-linked diseases.

A complex adenovirus vector that delivers FASL-GFP with combined prostate-specific and tetracycline-regulated expression

Cell-type-restricted transgene expression delivered by adenovirus vectors is highly desirable for gene therapy of cancer, as it can limit cytotoxic gene expression to tumor cells. However, many tumor- and tissue-specific promoters are weaker than the constitutively active promoters and are thus less effective. To combine cell-type specificity with high-level regulated transgene expression, we have developed a complex adenoviral vector. We have placed the tetracycline transactivator gene under the control of a prostate-specific ARR2PB promoter, and a mouse Tnfsf6 (encoding FASL)-GFP fusion gene under the control of the tetracycline responsive promoter. We have incorporated both expression cassettes into a single construct. We show that FASL-GFP expression from this vector is essentially restricted to prostate cancer cells, in which it can be regulated by doxycycline. Higher levels of prostate-specific FASL-GFP expression were generated by this approach than by driving the FASL-GFP expression directly with ARR2PB. More FASL-GFP expression correlated with greater induction of apoptosis in prostate cancer LNCaP cells. Mouse studies confirmed that systemic delivery of both the prostate-specific and the prostate-specific/tet-regulated vectors was well tolerated at doses that were lethal for FASL-GFP vector with CMV promoter. This strategy should be able to improve the safety and efficacy of cancer gene therapy using other cytotoxic genes as well.

Prostate-specific expression of Bax delivered by an adenoviral vector induces apoptosis in LNCaP prostate cancer cells

In prostate carcinoma, overexpression of the anti-apoptotic gene Bcl-2 has been found to be associated with resistance to therapies including radiation and androgen ablation. Restoring the balance of Bcl-2 family members may result in the induction of apoptosis in prostate cancer cells previously resistant to treatment. To accomplish this, a strategy involving overexpression of the pro-apoptotic gene Bax was executed. The use of cytotoxic genes such as Bax require selective expression of the gene. In this study, we examined the ability of selective expression of Bax protein directed by a prostate-specific promoter to induce apoptosis in human prostate carcinoma. A second-generation adenoviral vector was constructed with the modified prostate-specific probasin promoter, ARR2PB, directing expression of an HA-tagged Bax gene and a green fluorescent protein reporter translated from an internal ribosome entry site (ARR2PB.Bax.GFP). ARR2PB promoter activity is tightly regulated and highly prostate specific and is responsive to androgens and glucocorticoids. The prostate-specific promoter-Bax-GFP transgene cassette was inserted into a cloning site near the right inverted terminal repeat of the adenoviral vector to retain specificity of the promoter. LNCaP cells infected with Ad/ARR(2)PB.Bax.GFP showed high levels of Bax expression 48 h after infection resulting in an 85% reduction in cell viability. Importantly, LNCaP cells stably transfected to overexpress Bcl-2 showed similar patterns of cell death when infected with Ad/ARR(2)PB.Bax.GFP, an 82% reduction in cell viability seen 48 h after infection. Apoptosis was confirmed by measuring caspase activation and using the TUNEL assay. Tissue specificity was evaluated using A549 cells (lung adenocarcinoma), SK-Hep-1 (liver cancer) cells, and Hela (cervical cancer) cells which did not show detectable expression of virally delivered Bax protein or any increase in cell death. Systemic administration of Ad/ARR2PB. Bax.GFP in nude mice revealed no toxicity in liver, lung, kidney, or spleen. This study shows that infection with the second-generation adenovirus, ARR2PB.Bax.GFP, results in highly specific cytotoxicity in LNCaP cells, and that consequent overexpression of Bax in prostate carcinoma, even in the context of high levels of Bcl-2 protein, resulted in apoptosis. These results suggest that a second-generation adenovirus-mediated, prostate-specific Bax gene therapy is a promising approach for the treatment of prostate cancer.

Quantitative analysis of the EGF receptor autocrine system reveals cryptic regulation of cell response by ligand capture

Autocrine signaling is important in normal tissue physiology as well as pathological conditions. It is difficult to analyze these systems, however, because they are both self-contained and recursive. To understand how parameters such as ligand production and receptor expression influence autocrine activity, we investigated a human epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) loop engineered into mouse B82 fibroblasts. We varied the level of ligand production using the tet-off expression system and used metalloprotease inhibitors to modulate ligand release. Receptor expression was varied using antagonistic blocking antibodies. We compared autocrine ligand release with receptor activation using a microphysiometer-based assay and analyzed our data using a quantitative model of ligand release and receptor dynamics. We found that the activity of our autocrine system could be described in terms of a simple ratio between the rate of ligand production (VLT) and the rate of receptor production (VR). At a VLT/VR ratio of &lt;0.3, essentially no ligand was found in the extracellular medium, but a significant number of cell receptors (30-40%) were occupied. As the VLT/VR ratio increased from 0.3 towards unity, receptor occupancy increased and significant amounts of ligand appeared in the medium. Above a VLT/VR ratio of 1.0, receptor occupancy approached saturation and most of the released ligand was lost into the medium. Analysis of human mammary epithelial cells showed that a VLT/VR ratio of &lt;5×10−4was sufficient to evoke &gt;20% of a maximal proliferative response. This demonstrates that natural autocrine systems can be active even when no ligand appears in the extracellular medium.

A novel consecutive chain transfer reaction to p-methylstyrene and hydrogen during metallocene-mediated olefin polymerization

This paper describes the first example of consecutive chain transfer reaction, first to p-methylstyrene (or styrene) and then to hydrogen, during metallocene-catalyzed propylene polymerization by rac-Me(2)Si[2-Me-4-Ph(Ind)](2)ZrCl(2)/MAO complex. The PP molecular weight is inversely proportional to the molar ratio of [p-methylstyrene]/[propylene] and [styrene]/[propylene] with the chain transfer constants of k(tr)/k(p) = 1/6.36 and 1/7.5, respectively. Although hydrogen does not influence the polymer molecular weight, it greatly affects the catalyst activity. Each PP chain formed contains a terminal p-methylstyrene (or styrene) unit. The terminal p-MS unit can be metalated to form a stable polymeric anion for living anionic polymerization to prepare new PP diblock copolymers, such as PP-b-PS, which are very difficult to prepare by other methods. The overall process resembles a transformation reaction from metallocene to living anionic polymerization.

The use of Fas Ligand, TRAIL and Bax in gene therapy of prostate cancer

Prostate cancer is the second leading cause of cancer death in the United States. Treatment options for confined disease are generally successful in prolonging life but long-term cures (10-15 years) are elusive for the majority of patients. The prognosis for advanced extra-capsular prostate cancer is grim. However, we are now entering the era of gene therapy options for treatment of prostate cancer. The human genome project coupled with genomics and protemics are providing information that will lead to selection of genes for treatment of prostate cancer. The problem is the science of delivery lags behind knowledge of gene function. Thus, it is important to develop therapies that do not require delivery to 100% of tumor cells but which nevertheless kills the entire cancer by virtue of the bystander effect or other means. This review covers the use, in gene therapy, of apoptotic inducing molecules such as Fas Ligand, and TRAIL which are believed to induce bystander killing activity and Bax which also may function in a similar way.

Partial correction of the urinary concentrating defect in aquaporin-1 null mice by adenovirus-mediated gene delivery

The feasibility of water channel gene delivery to kidney tubules and microvessels was evaluated by delivery of an adenovirus encoding aquaporin 1 (AQP1-Ad5) to transgenic AQP1 null mice. In wild-type mice, AQP1 is expressed in kidney proximal tubule, thin descending limb of Henle, and descending vasa recta, where urine osmolality (Uosm) increases from 1000-1500 mOsm (before) to 2500-3500 mOsm after 36 hr of water deprivation. Uosm in AQP1 null mice remains nearly fixed at 650-750 mOsm. AQP1-Ad5 (with a CMV promoter) was generated and purified. Infection of CHO cells gave strong uniform AQP1 expression with plasma membrane localization and eightfold increased water permeability over noninfected cells. AQP1-Ad5 was delivered to 20 to 25-g AQP1 null mice by tail vein infusion (0-10(10) PFU). At 3-7 days, AQP1 protein expression was strongest in liver (approximately 20 microg of AQP1 protein per liver) and next strongest in kidney, with expression in proximal tubule apical and basolateral membranes, and renal microvessels. Functional analysis showed increased water permeability in apical membrane vesicles from proximal tubule. AQP1 expression was not detected in glomerulus, limb of Henle, or collecting duct. In water-deprived null mice receiving 5 x 10(9) PFU of AQP1-Ad5, Uosm increased by up to 510 mOsm (mean increase, 225 +/- 24 mOsm; n = 33 mice). Whereas the control null mice became lethargic and lost 34.2 +/- 0.6% body weight, the virus-treated mice remained relatively active and lost 32.3 +/- 0.7% body weight. Viral DNA and AQP1 transcript were detected in kidney and liver of null mice up to 17 weeks after virus infusion; partial correction of the urinary concentrating defect persisted for 3-5 weeks. These results demonstrate partial functional correction of a urinary concentrating defect by adenoviral delivery of the AQP1 gene.

Defective function of the cystic fibrosis-causing missense mutation G551D is recovered by genistein

The patch-clamp technique was used to investigate the effects of the isoflavone genistein on disease-causing mutations (G551D and DeltaF508) of the cystic fibrosis transmembrane conductance regulator (CFTR). In HeLa cells recombinantly expressing the trafficking-competent G551D-CFTR, the forskolin-stimulated Cl currents were small, and average open probability of G551D-CFTR was P(o) = 0.047 +/- 0.019. Addition of genistein activated Cl currents approximately 10-fold, and the P(o) of G551D-CFTR increased to 0.49 +/- 0.12, which is a P(o) similar to wild-type CFTR. In cystic fibrosis (CF) epithelial cells homozygous for the trafficking-impaired DeltaF508 mutation, forskolin and genistein activated Cl currents only after 4-phenylbutyrate treatment. These data suggested that genistein activated CFTR mutants that were present in the cell membrane. Therefore, we tested the effects of genistein in CF patients with the G551D mutation in nasal potential difference (PD) measurements in vivo. The perfusion of the nasal mucosa of G551D CF patients with isoproterenol had no effect; however, genistein stimulated Cl-dependent nasal PD by, on average, -2.4 +/- 0.6 mV, which corresponds to 16.9% of the responses (to beta-adrenergic stimulation) found in healthy subjects.

Efficient expression of CFTR function with adeno-associated virus vectors that carry shortened CFTR genes

Adeno-associated virus (AAV)-based vectors have been shown to be effective in transferring the cystic fibrosis gene (CFTR) into airway epithelial cells in animal models and in patients. However, the level of CFTR gene expression has been low because the vector cannot accommodate the CFTR gene together with a promoter. In this study, we described a strategy to reduce the size of the CFTR cDNA to allow the incorporation of an effective promoter with the CFTR gene into AAV vectors. We engineered and tested 20 CFTR mini-genes containing deletions that were targeted to regions that may contain nonessential sequences. Functional analyses showed that four of the shortened CFTRs (one with combined deletions) retained the function and the characteristics of a wild-type CFTR, as measured by open probability, time voltage dependence, and regulation by cAMP. By using an AAV vector with a P5 promoter, we transduced these short forms of CFTR genes into target cells and demonstrated high levels of CFTR expression. We also demonstrated that smaller AAV/CFTR vectors with a P5 promoter expressed the CFTR gene more efficiently than larger vectors or a vector in which CFTR gene was expressed from the AAV inverted terminal repeat sequence. The CFTR mini-gene with combined deletions was packaged into AAV virions more efficiently, generated higher titers of transducing virions, and more effectively transferred CFTR function into target cells. These new vectors should circumvent the limitations of AAV vector for CFTR expression. Our strategy also may be applicable to other genes, the sizes of which exceed the packaging limit of an AAV vector.

Reactivation of silenced, virally transduced genes by inhibitors of histone deacetylase

Retroviral and adeno-associated viral sequences can dramatically silence transgene expression in mice. We now report that this repression also occurs in stably infected HeLa cells when the cells are grown without selection. Expression of a transduced lacZ gene (rAAV/CMVlacZ) is silenced in greater than 90% of cells after 60 days in culture. Surprisingly, high-level expression can be reactivated by treating the cells with sodium butyrate or trichostatin A but not with 5-azacytidine. When cell clones with integrated copies of rAAV/CMVlacZ were isolated, lacZ expression was silenced in 80% of the clones; however, lacZ expression was reactivated in all of the silenced clones by treatment with butyrate or trichostatin A. The two drugs also reactivated a silenced globin gene construct (rAAV/HS2alphabetaAS3) in stably infected K562 cells. Trichostatin A is a specific inhibitor of histone deacetylase; therefore, we propose that hyperacetylation of histones after drug treatment changes the structure of chromatin on integrated viral sequences and relieves repression of transduced genes. The reactivation of silenced, transduced genes has implications for gene therapy. Efficient viral gene transfer followed by drug treatment to relieve suppression may provide a powerful combination for treatment of various genetic and infectious diseases.

Replication of rep-cap genes is essential for the high-efficiency production of recombinant AAV

Adenoassociated virus (AAV) has been developed as a vector for gene transfer because of its advantageous features: it is nonpathogenic, naturally replication-defective; it infects growth-arrested cells, and can transfer the therapeutic gene without co-delivery of any viral genes. However, a major obstacle in conducting systematic studies of AAV-mediated gene transfer in animal models is the difficulty of obtaining large quantities of recombinant virus. Recent development of AAV packaging cell lines has simplified the procedure of producing recombinant AAV (rAAV). However, the efficacy of producing large quantities of rAAV with these cell lines is yet to be demonstrated. In this study we have analyzed the difference between the replication of wild-type AAV and the production of rAAV. Using a combined single-plasmid system that carries both an AAV vector and the rep-cap genes, we have demonstrated that the AAV vector replicates to high number of copies whereas the rep-cap sequences remain unamplified in the virus-producing cells, When the copy number of rep-cap genes was increased by varying the vector/rep-cap ratio in the transfection mixture, the titer of rAAV increased proportionally. Thus, the titer of rAAV is limited by the low copy number of the rep-cap genes that results in an insufficient expression of the Rep and Cap proteins. We have also shown that generation of double-stranded replicating form of the vector DNA is accompanied by an amplified transgene expression. We propose that the increased gene expression from the accumulating double-stranded viral DNA is likely to be the mechanism by which wild-type AAV produces a large number of particles necessary to package the self-replicating AAV genomes. We conclude that mimicking this amplified expression of rep-cap genes may provide the key to produce high titers of rAAV.

Efficiency of plasmid delivery and expression after lipid-mediated gene transfer to human cells in vitro

Cationic liposome-mediated gene transfer has become increasingly important in the development of experimental therapies for human diseases, such as melanoma, human immunodeficiency virus infection, cystic fibrosis and alpha-1 antitrypsin deficiency. However, very little is known about the mechanisms by which lipid-mediated gene transfer occurs. We studied the kinetics of plasmid delivery and expression by using this technique. Plasmid entry in the cystic fibrosis respiratory epithelial cell line 2CFSME0-1 as well as in two other cell lines (HeP 2g and HeLa) occurred in 95 to 100% of cells within 1 hr of the initiation of lipid-mediated gene transfer. In hepatic and respiratory cells, transcription of a construct containing the cystic fibrosis transmembrane conductance regulator was observed in more than 80% of the cell population; similarly high levels of plasmid utilization were obtained in studies of HLA-B7 expression in human melanoma cells. Studies directly relevant to current human trials of lipid-mediated gene transfer indicate that plasmid entry, transcription and translation are often surprisingly efficient, and may occur in nearly 100% of human cells in culture when sensitive methods for detection are used. Furthermore, conventional X-gal immunohistochemistry markedly underestimates transfection efficiency during transient gene expression. These studies point to a new mechanistic understanding of the features that limit expression by using cationic liposomes.

Quantitative analysis of the packaging capacity of recombinant adeno-associated virus

Recombinant adeno-associated viruses (AAV) are among the most promising vectors for gene therapy of genetic diseases, including cystic fibrosis (CF). However, because of its small genome size, the capacity of AAV to package a therapeutic gene is limited. The efficiency of packaging the cystic fibrosis transmembrane conductance Regulator (CFTR) gene into AAV will be an important factor in determining whether recombinant AAV can be developed as a vector for transferring CFTR cDNA to the airway epithelia of patients with CF. Current understanding of the AAV biology suggests that AAV can package a genome slightly larger than the size of a wild-type genome. The precise range of the genome size and the efficiency of packaging have not been defined. Using a series of AAV vectors with progressively-increasing genome size, we were able to analyze quantitatively the packaging efficiency in relation to the vector size and to determine the size limit for packaging. The packaging efficiencies of AAV vectors of variable sizes were determined directly by assaying DNA contents of viral particles, and indirectly by analyzing their efficiency in transfer of a chloramphenicol acetyltransferase (CAT) reporter gene into target cells. Our studies showed that the optimal size of AAV vector is between 4.1 and 4.9 kb. Although AAV can package a vector larger than its genome size, up to 5.2 kb, the packaging efficiencies in this large size range were sharply reduced. When the AAV genome size was smaller than 4.1 kb, the packaging efficiency was also suboptimal. In contrast, when the size of the genome was less than half the length of the wild-type genome, two copies of the vector were packaged into each virion, suggesting that the copy number control during packaging is a "head-full" mechanism. Because the length of the minimal cDNA of CFTR is about 4.5 kb, these results suggest it is possible to package the CFTR gene into AAV if the combined length of transcriptional elements and ITRs is kept under 500 bp. The results of this study are important for directing the design of AAV vectors for efficient gene transfer, as well as for a better understanding of the mechanism of AAV genome packaging.

Systematic analysis of repeated gene delivery into animal lungs with a recombinant adenovirus vector

Adenovirus-based vectors are promising candidates for genetic therapy of cystic fibrosis (CF). Because adenoviruses naturally infect airway cells, they grow to very high titers, and the transgenes carried by the adenoviruses are expressed at high levels. In addition, adenoviruses are relatively safe because the disease caused by the wild-type virus is self-limiting. One disadvantage of adenovirual vectors is that the transgene expression would be transient because adenoviruses do not integrate their DNA into the genome of the host cells. Adenoviral gene delivery into the lungs is also complicated by the anatomy of the airways and the defense mechanisms of the recipient. To assess the feasibility of adenovirus-mediated gene therapy for CF, a recombinant adenovirus carrying a lacZ gene was delivered into animal lungs to study the efficiency and cellular distribution of gene transfer, the duration of gene expression, the possible histopathology of the lungs after gene transfer, and the efficacy of repeated administrations of the viral agent. The results of these studies demonstrate that (i) efficient gene transfer into animal lungs can be achieved; (ii) a near-homogenous delivery of the vectors can be achieved by airway instillation, although the pattern of transduction varies among individual animals; (iii) pathological effects are generally mild in CD1 mice; (iv) gene expression is transient; (v) repetitive gene transfer is achievable, but becomes progressively less efficient, and (vi) immune responses are induced against both the viral and transgene products.

Stable transduction of recombinant adeno-associated virus into hematopoietic stem cells from normal and sickle cell patients

Stable introduction of genes into human hematopoietic stem cells with self-renewing potential is a necessary requirement for gene therapy strategies. We have developed an adeno-associated virus (AAV) vector and a partial packaging cell line that produces recombinant AAV at a titer of 10(8) transducing particles per milliliter. A high-titer viral stock containing the CMV/lacZ gene was used to transfer lacZ sequences into CD34+ Lin-Thy+ hematopoietic stem cells purified from normal and homozygous sickle cell patients. After infection, the cells were cultured in two ways. In the first set of experiments, the cell were expanded 300-fold in liquid culture for 21 days and plated in methylcellulose. Burst-forming units-erythroid (BFU-E) and colony-forming units-granulocyte/macrophage (CFU-GM) were then analyzed for lacZ sequences. In the second set of experiments, infected cells were cultured for 6 weeks under conditions that maintain long-term culture-initiating cells (LTC-IC). Progenitors were plated in methylcellulose, and BFU-E were analyzed for lacZ DNA. Stable transduction of lacZ sequences was observed in 25% of the colonies in both sets of experiments. These results demonstrate for the first time that LTC-IC can be transduced stably with a recombinant AAV vector. The results suggest that AAV may be a useful vector for genetic therapy of sickle cell disease and other hematopoietic disorders.

Epitope tagging permits cell surface detection of functional CFTR

The cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation-activated Cl channel responsible for adenosine 3',5'-cyclic monophosphate (cAMP)-induced Cl secretion across the apical membranes of epithelial cells. To optimize its detection for membrane localization studies, we tagged CFTR with epitope sequences at the carboxy terminus or in the fourth external loop. When epitopes were added to the fourth external loop, the N-linked glycosylation sites in that loop were either preserved or they were mutated to produce a deglycosylated CFTR (dgCFTR). Tagged CFTRs were expressed in HeLa cells, and their cAMP-sensitive Cl permeability was assayed using the halide-sensitive fluorophore SPQ. CFTRs containing the M2 epitope showed halide permeability responses to cAMP, whereas cells expressing CFTR with the hemagglutinin (HA) tag showed little or no cAMP response. Xenopus oocytes expressing dgCFTR, with or without the M2 epitope, showed Cl conductance responses that were 20% of the wild-type response, whereas M2-tagged constructs retaining the glycosylation sites responded like wild-type CFTR. External M2-tagged CFTR was detected in the surface membrane of nonpermeabilized cells. The surface expression of the mutant M2-tagged CFTRs correlated with processing of these mutants (Gregory et al. Mol. Cell. Biol. 11:3886-3893, 1991). M2-901/CFTR is a useful reporter for the trafficking of wild-type and mutant CFTRs to the cell surface.

Differential requirement of CD28 costimulation for activation of murine CD8+ intestinal intraepithelial lymphocyte subsets and lymph node cells

The CD8+CD4- (CD8+) murine small intestinal intraepithelial lymphocytes (IELs) contain two subpopulations, one expressing alpha alpha-CD8 homodimers and another alpha beta-CD8 heterodimers. In this study, plate-bound anti-TCR beta-chain (TCR-beta) mAb alone or combined with anti-CD28 mAb is used as a model system to study activation requirement of these two CD8+ IEL subsets. In contrast to CD8+ lymph node (LN) cells that require both TCR and CD28 triggering for activation, alpha beta-CD8+ IELs proliferate and produce IL-2 and IFN-gamma when stimulated with anti-TCR-beta mAb alone, and soluble CTLA-4 Ig has no effect on their responses. On the other hand, alpha alpha-CD8+ IELs neither make IL-2 or IFN-gamma nor proliferate even when both stimuli are provided. However, alpha alpha-CD8+ IELs are capable of proliferation in both CD8+ IEL subsets is lower than in CD8+ LN cells, which contributes to the weaker and delayed response of CD8+ IELs.

Differential requirement of CD28 costimulation for activation of murine CD8+ intestinal intraepithelial lymphocyte subsets and lymph node cells

The CD8+CD4- (CD8+) murine small intestinal intraepithelial lymphocytes (IELs) contain two subpopulations, one expressing alpha alpha-CD8 homodimers and another alpha beta-CD8 heterodimers. In this study, plate-bound anti-TCR beta-chain (TCR-beta) mAb alone or combined with anti-CD28 mAb is used as a model system to study activation requirement of these two CD8+ IEL subsets. In contrast to CD8+ lymph node (LN) cells that require both TCR and CD28 triggering for activation, alpha beta-CD8+ IELs proliferate and produce IL-2 and IFN-gamma when stimulated with anti-TCR-beta mAb alone, and soluble CTLA-4 Ig has no effect on their responses. On the other hand, alpha alpha-CD8+ IELs neither make IL-2 or IFN-gamma nor proliferate even when both stimuli are provided. However, alpha alpha-CD8+ IELs are capable of proliferation in both CD8+ IEL subsets is lower than in CD8+ LN cells, which contributes to the weaker and delayed response of CD8+ IELs.

Intratracheal gene delivery with adenoviral vector induces elevated systemic IgG and mucosal IgA antibodies to adenovirus and beta-galactosidase

One major concern about using adenoviral vectors for repetitive gene delivery to lung epithelial cells is the induction of an immune response to the vector, thus, impeding effective gene transduction. To assess the immune response to the adenoviral vector, repetitive intratracheal (i.t.) gene dosing was performed in CD-1 mice using the replication-deficient adenovirus 5 (Ade5) vector carrying the lacZ gene, and compared to the antibody responses induced by conventional intranasal (i.n.) and intraperitoneal (i.p.) routes of immunization. Kinetics of serum IgG, IgA, and IgM antibody responses to the adenoviral vector and to beta-galactosidase (beta-Gal) were evaluated. Two or three adenoviral vector doses given by i.t., i.n., or i.p. routes resulted in serum IgG titers in excess of 1:200,000, whereas serum IgM and IgA were moderately induced. Analysis of the predominant murine IgG subclass was determined to be IgG2b and IgG2a. To determine the localization of this antibody response, the ELISPOT assay was employed. Lymphocytes were isolated from the lung, the lower respiratory lymph nodes (LRLN), the nasal passages (NP), and the spleen. For i.t- and i.n.-administered mice, the highest IgA spot-forming cell (SFC) response to Ade5 and beta-Gal was located in the NP and in the lung. Both the lung and the LRLN showed elevated numbers of IgG SFCs (4- to 12-fold greater than splenic IgG SFC response) for Ade5 and beta-Gal. This evidence suggests that the lung and associated lymphoid tissues were the source for serum antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Transport of a lysosomally targeted Rous sarcoma virus envelope glycoprotein involves transient expression on the cell surface

The details of intracellular transport pathways for glycosylated proteins remain incompletely described. We previously described a mutant Rous sarcoma virus envelope glycoprotein (gp), mu 26, with an altered membrane-spanning domain that was targeted to lysosomes after traversing the trans-Golgi. This mutant protein was not detectable on the cell surface by immunofluorescence, but its pathway for degradation remained unclear. To investigate this we have employed a second env mutation, S19, that results in a protein which is defective for normal cleavage/activation by intracellular enzymes, but remains susceptible to cleavage by extracellular proteases. Cleavage/activation of the double mutant by trypsin, which could only occur if it was exposed on the cell surface, was observed, indicating that the plasma membrane is an intermediate destination in the transport of this mutant protein. To substantiate these results, cells expressing the mu 26 glycoprotein were incubated with an antibody specific for the native protein in the presence of chloroquine. The specific accumulation of this antibody/gp complex in vesicles, as detected by internal immunofluorescence, confirmed the trypsin cleavage results. We conclude that this rapidly degraded mutant protein is transported from the trans-Golgi to the cell surface, where it is only transiently exposed, and then rapidly endocytosed and lysosomally degraded. The relevance of these results to the targeting of lysosomal proteins is discussed.

Mutations within the proteolytic cleavage site of the Rous sarcoma virus glycoprotein define a requirement for dibasic residues for intracellular cleavage

We investigated the amino acid sequence requirements for intracellular cleavage of the Rous sarcoma virus glycoprotein precursor by introducing mutations into the region encoding the cleavage recognition site (Arg-Arg-Lys-Arg). In addition to mutants G1 (Arg-Arg-Glu-Arg) and Dr1 (deletion of all four codons) that we have reported on previously (L. G. Perez and E. Hunter, J. Virol. 61:1609-1614, 1987), we constructed two additional mutants, AR1 (Arg-Arg-Arg-Arg), in which the highly conserved lysine is replaced by an arginine, and S19 (Ser-Arg-Glu-Arg), in which no dibasic pairs remain. The results of these studies demonstrate that when the cleavage sequence is deleted (Dr1) or modified to contain unpaired basic residues (S19), intracellular cleavage of the glycoprotein precursor is completely blocked. This demonstrates that the cellular endopeptidase responsible for cleavage has a stringent requirement for the presence of a pair of basic residues (Arg-Arg or Lys-Arg). Furthermore, it implies that the cleavage enzyme is not trypsinlike, since it is unable to recognize arginine residues that are sensitive to trypsin action. Substitution of the mutated genes into a replication-competent avian retrovirus genome showed that cleavage of the glycoprotein precursor was not required for incorporation into virions but was necessary for infectivity. Treatment of BH-RCAN-S19-transfected turkey cells with low levels of trypsin resulted in the release of infectious virus, demonstrating that exogenous cleavage could generate a biologically active glycoprotein molecule.

Purification of spectrin and its subunits by high-performance liquid chromatography

Technological and methodological advances in the techniques of structural and biological studies of proteins have reduced the required amount of sample. In conjunction with these advances, high-performance liquid chromatography (HPLC) has emerged as a technique of high utility for the purification of complex molecules. Using a combination of size-exclusion and reversed-phase HPLC and ionic buffers containing sodium dodecyl sulfate, the red cell membrane-associated high-molecular-weight polypeptide spectrin and its subunits have been purified. The system described in this paper is fast, reproducible and quantitative.