Characterization of immortalized mesenchymal stem cells derived from foetal porcine pancreas

Islet replacement therapy is limited by shortage of donor islet cells. Usage of islet cells derived from porcine pancreatic stem cells (PSCs) is currently viewed as the most promising alternative for human islet transplantation. However, PSCs are rare and have a finite proliferative lifespan. In this study, we isolated and established an immortalized mesenchymal stem cell (MSC) line derived from foetal porcine pancreas, by transfecting human telomerase reverse transcriptase (hTERT) and called these immortalized pancreatic mesenchymal stem cells (iPMSCs). The iPMSCs have been cultured for more than 80 passages and have capacity to differentiate into neurons, cardiomyocytes, germ cells and islet-like cells, analysed by morphology, RT-PCR, western blotting, immunofluorescence, immunocytochemistry and transplantation assay. Islets derived from iPMSCs reversed hyperglycaemia in streptozotocin-induced diabetic mice and secreted insulin and C-peptide in vitro. These results demonstrated that iPMSCs might provide unlimited resources for islet replacement therapy and models for functional cell differentiation.

Establishment and biological characterization of fibroblast cell line from the Langshan chicken

OBJECTIVE

We needed to establish an embryonic fibroblast cell line from the Langshan chicken (LSCEF61) to preserve their important genetic resources at the cellular level.

MATERIAL AND METHODS

The cell line was established from 9-day-old embryos by direct explant culture and cryopreservation techniques. Cell morphology, dynamic proliferation and any contamination present were tested, and the karyotype and levels of isoenzymes of lactic dehydrogenase and malic dehydrogenase were analysed. Four types of fluorescent protein exogenous genes for pEGFP-C(1), pEGFP-N(3), pEYFP-N(1) and pDsRed1-N(1) were transfected into the cells.

RESULTS

Showed that the cells were healthy and were of spindle shaped structure, without change in morphology. Cell growth curves were of typical S-shape. Assays for microbial contamination were negative. The LSCEF61 line showed no cross-contamination when assessed by isoenzyme analysis. Chromosome number (2n) = 78 on more than 90% of occasions. The four types of fluorescent protein extro-genes appeared to be expressed effectively with high transfection efficiency between 15.6% and 38.6%.

CONCLUSION

The cell line met each of the quality control standards required for the American Type Culture Collection. It had not only preserved the genetic resources of the important Langshan chicken at the cellular level, but also provided valuable material for genomic, post-genomic and somatic cell cloning research and other applications.

Wealth of opportunity - the C1 domain as a target for drug development

The diacylglycerol-responsive C1 domains of protein kinase C and of the related classes of signaling proteins represent highly attractive targets for drug development. The signaling functions that are regulated by C1 domains are central to cellular control, thereby impacting many pathological conditions. Our understanding of the diacylglycerol signaling pathways provides great confidence in the utility of intervention in these pathways for treatment of cancer and other conditions. Multiple compounds directed at these signaling proteins, including compounds directed at the C1 domains, are currently in clinical trials, providing strong validation for these targets. Extensive understanding of the structure and function of C1 domains, coupled with detailed insights into the molecular details of ligand - C1 domain interactions, provides a solid basis for rational and semi-rational drug design. Finally, the complexity of the factors contributing to ligand - C1 domain interactions affords abundant opportunities for manipulation of selectivity; indeed, substantially selective compounds have already been identified.

Time-resolved fluorescence polarization dynamics and optical imaging of Cytate: a prostate cancer receptor-targeted contrast agent

Cypate-octreote peptide analogue conjugate (Cytate) was investigated as a prostate cancer receptor-targeted contrast agent. The absorption and fluorescence spectra of Cytate were ranged in the near-infrared "tissue optical window." Time-resolved investigation of polarization-dependent fluorescence emitted from Cytate in solution as well as in cancerous and normal prostate tissues was conducted. Polarization preservation characteristics of Cytate in solution and tissues were studied. Fluorescence intensity emitted from the Cytate-stained cancerous prostate tissue was found to be much stronger than that from the Cytate-stained normal prostate tissue, indicating more Cytate uptake in the former tissue type. The polarization anisotropy of Cytate contained in cancerous prostate tissue was found to be larger than that in the normal prostate tissue, indicating a larger degree of polarization preservation in Cytate-stained cancerous tissue. The temporal profiles of fluorescence from Cytate solution and from Cytate-stained prostate tissue were fitted using a time-dependent fluorescence depolarization model. The photoluminescence imaging of Cytate-stained cancerous and normal prostate tissues was accomplished, showing the potential of Cytate as a fluorescence marker for prostate cancer detection.

High prevalence of pineal cysts in healthy adults demonstrated by high-resolution, noncontrast brain MR imaging

BACKGROUND AND PURPOSE

Although the prevalence of pineal cysts in autopsy series has been reported as being between 25% and 40%, MR studies have documented their frequency to range between 1.5% and 10.8%. The purpose of this high-resolution brain MR imaging study at 1.9T was to determine the prevalence of pineal cysts in healthy adults.

MATERIALS AND METHODS

Brain MR images of 100 healthy young volunteers were randomly selected from our International Consortium for Brain Mapping project data base. Cysts were detected as circular areas of isointensity relative to CSF on both 3D gradient-echo T1-weighted and 2D fast spin-echo T2-weighted images. The inner diameters of all visualized pineal cysts were measured, and a criterion of 2.0 mm of the largest inner cross-sectional diameter was used to categorize cysts as being either small cystic changes (<2.0-mm diameter) or pineal cysts (>2.0-mm diameter).

RESULTS

Twenty-three percent (23/100) of the volunteers had pineal cysts with a mean largest inner cross-sectional diameter of 4.3 mm (range, 2-14 mm); 13% (13/100) demonstrated cystic changes involving the pineal gland with the largest inner cross-sectional diameter of less than 2.0 mm. There was a slight female predominance. Two subjects with long-term follow-up scans showed no symptoms or changes in the size of their pineal cysts.

CONCLUSION

On high-resolution MR imaging, the prevalence of pineal cysts was 23% in our healthy group of adults, which is consistent with previous autopsy studies. Long-term follow-up studies of 2 cases demonstrated the stability of the cysts.

Organ motion prediction for medical treatments

In extracorporeal shock wave lithotripsy (ESWL) and radiotherapy, real time tracking of the position of renal stones or tumors is of great importance. When the treatment system incorporates many delay factors, the treated position and the expected position may significantly differ. In this study, linear prediction is used to examine if future values from real-time tracking trajectories can be predicted accurately. The results presented here shows that predicted values can be used for the treatment targeting compensating for the systems delays. The use of up to the third future predicted value introduces less than 5% average error from the actual future positions.

Prognostic factors for patients with metastatic urothelial carcinoma treated with cisplatin and 5-fluorouracil-based regimens

14583

Background: Combination of cisplatin and 5-fluorouracil (5-FU) has activity in metastatic urothelial carcinoma (UC). To identify patient subgroups most likely to benefit and compare survival to that in previously described patient series, long-term survival, as a function of known and suspected prognostic variables, was determined. Methods: The survival status of 79 patients with metastatic urothelial cancer treated on two phase II trials of cisplatin and 5-FU-based regimens was updated. P-HDFL regimen (n = 35) was cisplatin 35 mg/m2 IV 24hr D1, 8; 5-FU 2,600 mg/m2 and leucovorin 300 mg/m2 IV 24hr D1, 8, 15; repeated every 28 days (Cancer 2006, in press). TP-HDFL regimen (n = 44) was paclitaxel 70 mg/m2 IV 1hr D1, 8; cisplatin 35 mg/m2 IV 24hr D1, 8; 5-FU 2,000 mg/m2 and leucovorin 300 mg/m2 IV 24hr D1, 8; repeated every 21 days (Proc ASCO 22:407b, 2003 [abstr 1637]). Univariate and multivariate Cox proportional hazards models were constructed. Results: Karnofsky performance status (KPS) <80%, presence of visceral metastasis, and alkaline phosphatase ≥220 U/l are three significant poor prognostic factors for survival. The percentage of patients who harbored zero-risk, one- or two-risk, and three-risk categories was 27%, 61%, and 13%, respectively. Among patients with no risk factors, the median survival time was not reached yet after a median follow-up of 43.0 months. Patients with one or two risk factors had a median survival duration of 12.3 months (95% CI 8.6–16.0). Patients with all three risk factors had a median survival of 4.6 months (95% CI 1.4–7.9). There was a significant difference in survival between the three groups (P < .0001). Conclusions: Previously described prognostic factors, including KPS <80%, visceral metastasis, and alkaline phosphatase ≥220 U/l, for survival in metastatic UC were confirmed in patients treated with cisplatin and 5-FU-based regimen.

No significant financial relationships to disclose.

Spectral polarization imaging of human prostate cancer tissue using a near-infrared receptor-targeted contrast agent

The Cypate-Bombesin Peptide Analogue Conjugate (Cybesin) was used as a prostate tumor receptor-targeted contrast agent. The absorption and fluorescence spectra of Cybesin were measured and shown to exist in the NIR tissue "optical window". The spectral polarization imaging of Cybesin-stained prostate cancerous and normal tissues shows that prostate cancerous tissue takes-up more Cybesin than that of prostate normal tissue, making Cybesin a potential marker of prostate cancer.

Mobility of polymer chains confined at a free surface

Dynamic secondary ion mass spectrometry was used to investigate the chain mobility of polystyrene (MW ranging from 4.3 to 957 kg/mol) at the free surface. The data show that the diffusion coefficient was reduced relative to the bulk value within a distance, d < or = 4R(g), from the surface and scaled as 1/N(2.5) at fixed d. These results are in excellent agreement with self-consistent field calculations of the surface segmental distribution and provide the first direct confirmation of various theoretical models that predict asymmetric segmental fluctuation which arises from surface induced orientation of polymer chains.

Cooking oil fume-induced cytokine expression and oxidative stress in human lung epithelial cells

Epidemiological studies have shown an association between exposure to indoor air pollution from Chinese-style cooking and risk of lung cancer among Chinese females. Several toxic substances have been identified in cooking oil fumes (COF) collected from heated rapeseed oil. In this study, we examined the biological effects of COF on CL3 human lung epithelial cells. Exposure to 200 microg/ml COF significantly reduced cell growth within 4 days. In addition, we examined the effect of COF on TGFbeta1, TGFbeta2, IL-6, IL-8, and IFN-gamma gene expressions with the RT-PCR method. We found that TGFbeta1 mRNA levels increased after exposure to 200 microg/ml COF for 24 h. Similarly, exposure to 10 microM benzo[a]pyrene or 100 nM 12-O-tetradecanoylphorbol-13-acetate increased TGFbeta1 mRNA levels at 24 h. The mRNA levels of TGFbeta2, IL-6, IL-8, and IFN-gamma did not increase after treatment with COF, benzo[a]pyrene, or 12-O-tetradecanoylphorbol-13-acetate. COF-induced TGFbeta1 production was confirmed by quantification of TGFbeta1 in conditioned medium with enzyme-linked immunosorbent assay. Exposure to 200 microg/ml COF significantly increased TGFbeta1 secretion in a time-dependent and dose-dependent manner. It has been demonstrated that reactive oxygen intermediates induce TGFbeta1 gene expression. When CL3 cells were exposed to 200 microg/ml COF for 15 min, there was an increase in intracellular peroxide formation with the dichlorofluorescein method. Furthermore, treatment with 200 microg/ml COF for 12 h also significantly induced lipid peroxidation in CL3 cells. Our results show that exposure to COF inhibits cell growth, increases TGFbeta1 secretion, and induces oxidative stress in CL3 lung epithelial cells. This suggests that TGFbeta1 and oxidative stress play a role in the biological effects of COF on lung epithelial cells.

[Rat keratinocyte primary cultures based on conductive polypyrrole primary cell culture technique]

Orthogonal experimental design has been applied to study the suitable cell culture medium and condition of conductive polypyrrole on rat keratinocyte cell cultures. The results showed that one thousand milliliters of complete minimum essential medium(CMEM) which contained 900 ml minimum essential medium(MEM), 10% fetal bovine serum(FBS), 1% NEAA, 6 ml insulin and 10 mg hydrocortisone was fit for keratinocyte cell culture. And the conductive polypyrrole obtained with 10 mA current density for 100 second switching times, given 100 mV electrical stimulation voltage for 2 hours, would stimulate the growth of rat keratinocyte cell in vitro cultures. The cell density under culture conditions described above was 1.30 times as high as that under routine culture conditions.

Temporal relationship between cytochrome c release and mitochondrial swelling during UV-induced apoptosis in living HeLa cells

During apoptosis, cytochrome c is released from mitochondria to the cytosol to activate a caspase cascade, which commits the cell to the death process. It has been proposed that the release of cytochrome c is caused by a swelling of the mitochondrial matrix triggered by the apoptotic stimuli. To test this theory, we measured directly the dynamic re-distribution of green fluorescence protein (GFP)-tagged cytochrome c and morphological change of mitochondria within living HeLa cells during u.v.-induced apoptosis. We observed that mitochondria did not swell when cytochrome c was released from mitochondria to cytosol during apoptosis. Instead, mitochondria swelled to spherical shapes within 10 minutes of cytochrome c release. This finding strongly suggests that cytochrome c release in apoptosis was not caused by mitochondrial swelling. This conclusion was further supported in two separated experiments using an immunostaining method and carbonyl cyanide m-chlorophenyl-hydrazone (CCCP) treatment. In addition, we found evidence that cytochrome c was also released before mitochondrial swelling in apoptosis induced by other cell death-inducing treatments, including tumor necrosis factor (TNF) and actinomycin D.

Genetic polymorphisms of NAD(P)H quinone oxidoreductase, CYP1A1 and microsomal epoxide hydrolase and lung cancer risk in Nanjing, China

Genetic variations in metabolic activation or detoxification enzymes have been thought to contribute to individual differences in lung cancer susceptibility. Genetic polymorphisms of NAD(P)H quinone oxidoreductase (NQO1), cytochrome P4501A1 (CYP1A1) and microsomal epoxide hydrolase (HYL1) have been associated with increased lung cancer risk in Asian populations. In the present study, the possibility of an association of NQO1, CYP1A1 and HYL1 genetic polymorphisms with lung cancer was examined among residents in Nanjing, China. A total of 84 lung cancer patients and 84 control subjects were matched by age, gender, occupation and smoking status. No significant association was observed for these genetic polymorphisms with the overall incidence of lung cancer. When the groups were stratified according to smoking status, we found that smokers carrying the HYL1*2 allele had a higher relative risk for lung cancer Odds ratio ((OR), 5.66; 95% confidence interval (95% CI), 1.71-18.68). The association was also found with squamous cell carcinoma (OR, 3.23; 95% CI, 1.00-10.38). Our results suggest that HYL1*2 polymorphism might be a risk factor for smoking-associated lung cancer in China.

Cerebral hemodynamic response in Chinese (first) and English (second) language processing revealed by event-related functional MRI

Comparative functional neuroimaging studies using the block design paradigm have previously demonstrated that there are no significant differences in the location of areas of cerebral activation when native Chinese speakers independently process single words or sentences in both the Chinese (first) and English (second) languages. While it has also been documented that significant domains of brain response include the inferior to middle left frontal lobe, the latency, amplitude and duration of the associated hemodynamic changes during isolated neural processing of Chinese and English languages still remain unknown. The aim of this study, therefore, was to examine the characteristics of the hemodynamic alterations in the above-mentioned regions with event-related functional MRI (ER-fMRI) when native Chinese speakers performed verb generation tasks in both the Chinese (first) and English (second) languages. Our results demonstrate the presence of a similar neural activity-induced hemodynamic response in the inferior to middle left frontal lobe during both tasks. Further, there were also no statistically significant differences among the variables that described the hemodynamic response curves. These findings strongly imply that the underlying neural mechanism for Chinese (first) and English (second) language processing may be similar in native Chinese speakers.

Application of the Fluorescence Resonance Energy Transfer Method for Studying the Dynamics of Caspase-3 Activation during UV-Induced Apoptosis in Living HeLa Cells

Activation of caspase-3 is a central event in apoptosis. We have developed a GFP-based FRET (fluorescence resonance energy transfer) probe that is highly sensitive to the activation of caspase-3 in intact living cells. This probe was constructed by fusing a CFP (cyan fluorescent protein) and a YFP (yellow fluorescent protein) with a specialized linker containing the caspase-3 cleavage sequence: DEVD. The linker design was optimized to produce a large FRET effect. Using purified protein, we observed a fivefold change in the fluorescence emission ratio when the probe was cleaved by caspase-3. To demonstrate the usefulness of this method, we introduced this FRET probe into HeLa cells by both transient and stable transfection. We observed that during UV-induced apoptosis, the activation of caspase-3 varied significantly between different cells; but once the caspase was activated, the enzyme within the cell became fully active within a few minutes. This technique will be highly useful for correlating the caspase-3 activation with other apoptotic events and for rapid-screening of potential drugs that may target the apoptotic process.

[Detection of aflatoxin-albumin adducts in human serum and its application]

Exposure to aflatoxin B1 (AFB1) is one of the major risk factors in the etiology of human hepatocellular carcinoma (HCC). The development of highly sensitive and specific methods for detecting AFB1 and its macromolecular biomarkers are critical for identifying individuals at risk for hepatocellular carcinoma. The detection of aflatoxin-albumin adducts (AFB-ALB) in serum has been used to investigate the relationship between aflatoxin exposure and HCC. A more sensitive and reliable method to detect AFB-ALB in serum was modified by separating serum albumin with Microcon-50 microconcentrators in stead of using precipitation. The method could separate serum albumin quickly and make protein digested in the same container. Thus, the step for transferring samples was reduced and recovery rate was improved. The AFB-ALB adducts were then determined by radioimmunoassay. The AFB-ALB adducts of human serum samples from Qidong, Jiangsu Province, and Fusui, Guangxi Zhuang Autonomous Region of the People's Republic of China were detected. The results indicated that the exposure of AFB1 is common and the positive rate for AFB-ALB adducts in serum of these populations is high.

Tamm-Horsfall protein binds to type 1 fimbriated Escherichia coli and prevents E. coli from binding to uroplakin Ia and Ib receptors

The adherence of uropathogenic Escherichia coli to the urothelial surface, a critical first step in the pathogenesis of urinary tract infection (UTI), is controlled by three key elements: E. coli adhesins, host receptors, and host defense mechanisms. Although much has been learned about E. coli adhesins and their urothelial receptors, little is known about the role of host defense in the adherence process. Here we show that Tamm-Horsfall protein (THP) is the principal urinary protein that binds specifically to type 1 fimbriated E. coli, the main cause of UTI. The binding was highly specific and saturable and could be inhibited by d-mannose and abolished by endoglycosidase H treatment of THP, suggesting that the binding is mediated by the high-mannose moieties of THP. It is species-conserved, occurring in both human and mouse THPs. In addition, the binding to THP was much greater with an E. coli strain bearing a phenotypic variant of the type 1 fimbrial FimH adhesin characteristic of those prevalent in UTI isolates compared with the one prevalent in isolates from the large intestine of healthy individuals. Finally, a physiological concentration of THP completely abolished the binding of type 1 fimbriated E. coli to uroplakins Ia and Ib, two putative urothelial receptors for type 1 fimbriae. These results establish, on a functional level, that THP contains conserved high-mannose moieties capable of specific interaction with type 1 fimbriae and strongly suggest that this major urinary glycoprotein is a key urinary anti-adherence factor serving to prevent type 1 fimbriated E. coli from binding to the urothelial receptors.

Cytosolic Ca(2+) signal is involved in regulating UV-induced apoptosis in hela cells

Results of recent studies using BAPTA/AM have raised a serious question on whether Ca(2+) signal is truly involved in regulating the progression of apoptosis. To resolve this question, we examined the differential effects of three different Ca(2+) signaling blockers (BAPTA/AM, membrane-impermeant BAPTA, and heparin) on UV-induced apoptosis in HeLa cells. We found that although the membrane-permeable form of BAPTA (i.e., BAPTA/AM) could not inhibit cell death, the membrane-impermeant form of BAPTA, loaded into the cytosol by electroporation, clearly protected cells from entering apoptosis. Furthermore, when we injected heparin to block Ca(2+) release from the endoplasmic reticulum (ER) to cytosol, apoptosis was greatly suppressed. These findings strongly suggest that elevation of cytosolic Ca(2+) is part of the signal that drives the progression of apoptosis. The negative result of BAPTA/AM is probably due to its dual effect on subcellular Ca(2+) distribution; besides suppressing the Ca(2+) elevation in cytosol, BAPTA/AM can also enter into the ER to reduce the free Ca(2+) level there. The depletion of Ca(2+) in ER is believed to stimulate apoptosis and thus would counterbalance the protection effect of BAPTA/AM in suppressing the cytosolic Ca(2+) elevation.