[Identification of the feature of immune cells infiltration in inherited renal carcinoma with von Hippel-Lindau syndrome]

Objective: To investigate the feature of immune cells infiltration in inherited renal carcinoma with von Hippel-Lindau (VHL) syndrome and their relationship with clinicopathological characteristics and prognosis. Methods: The samples were collected from patients with VHL syndrome renal carcinoma who were diagnosed and treated surgically at the Department of Urology, Peking University First Hospital from 2010 to 2019. RNA-Seq was performed on 6 pairs of VHL syndrome renal carcinoma and adjacent normal tissues. To identify the specific infiltrated immune cells, RNA-Seq data was converted into the infiltration data of 14 types of immune cells using the TIP tool. Immunohistochemical staining was used to verify the expression of the markers of these specific infiltrated immune cells in the paraffin sections of 54 paired VHL syndrome renal carcinoma and adjacent normal tissues, and to analyze their relationship with clinicopathological characteristics and prognosis. Results: Compared with adjacent normal tissues, CD4 Naive infiltration level was significantly down-regulated (0.289±0.009 vs 0.200±0.012,P<0.001) and CD4 Memory infiltration level was significantly up-regulated (0.123±0.014 vs 0.222±0.016,P<0.001) in VHL syndrome renal carcinoma. Immunohistochemical staining results showed that CD45RA (a CD4 Naive cell marker) expression was significantly reduced (50.9±1.9 vs 15.6±0.9,P<0.001) and CD45RO (a CD4 Memory cell marker) expression was significantly increased (22.2±1.1 vs 80.8±4.3,P<0.001) in VHL syndrome renal carcinoma. Besides, lower CD45RA expression and higher CD45RO expression were associated with higher histological grade, advanced tumor stage and shorter disease-free survival (all P<0.01). In addition, CD45RA expression was positively correlated with VHL expression (r=0.693 3, P<0.000 1) and CD45RO expression was negatively correlated with VHL expression (r=-0.609 0, P<0.000 1). Conclusions: This study found that CD4 Naive and CD4 Memory cells may be differentially infiltrated immune cells in VHL syndrome renal carcinoma, and their infiltration levels were associated with the expression of VHL and the prognosis of patients.

[Clinicopathological and prognostic characteristics of clear cell papillary renal cell carcinoma]

Objective: To analyze the epidemiological, clinicopathological and prognostic characteristics of clear cell papillary renal cell carcinoma (CCPRCC) based on Chinese patient population. Method: Patients with renal cell carcinoma diagnosed at Peking University First Hospital from June 2016 to June 2020 were included in this study based on the inclusion and exclusion criteria. All cases were grouped according to CCPRCC, clear cell renal cell carcinoma (ccRCC), and papillary renal cell carcinoma (pRCC), and the general clinical, postoperative pathological and follow-up data of the patients were retrospectively analyzed. Result: A total of 18 CCPRCC patients were enrolled in this study, accounting for 0.44% (18/4 110) of the postoperative pathologically confirmed renal cell carcinoma cases in our hospital during this time period. The age range of the included patients was 28-86 years old, with a median age of 49.5 years old. There were 11/18 males and 7/18 females. All CCPRCC patients had no family history of renal malignant tumors. Among them, only one patient with CCPRCC had related clinical symptoms, that was intermittent waist and abdomen pain, while the other 17 cases were found by physical examination without any related symptoms. Compared with ccRCC and pRCC, there was no significant difference in their end stage renal disease history(χ²_ccRCC=0.291, χ²_pRCC=1.161,all P>0.05). The maximum diameter of CCPRCC tumor was smaller than pRCC (χ²=-2.280,P =0.027) but not significantly different from ccRCC (χ²=-0.579,P =0.565). The majority of patients with CCPRCC were in pT1, their pathological stage was earlier than the other two types, and their overall survival was better than ccRCC and pRCC (P<0.05). Conclusion: CCPRCC is a type of renal cell carcinoma with unique epidemiology, clinicopathology and prognostic characteristics. Patients with this subtype have an earlier clinical stage and a better prognosis than ccRCC and pRCC.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Efficient production of male Wolbachia-infected Aedes aegypti mosquitoes enables large-scale suppression of wild populations

The range of the mosquito Aedes aegypti continues to expand, putting more than two billion people at risk of arboviral infection. The sterile insect technique (SIT) has been used to successfully combat agricultural pests at large scale, but not mosquitoes, mainly because of challenges with consistent production and distribution of high-quality male mosquitoes. We describe automated processes to rear and release millions of competitive, sterile male Wolbachia-infected mosquitoes, and use of these males in a large-scale suppression trial in Fresno County, California. In 2018, we released 14.4 million males across three replicate neighborhoods encompassing 293 hectares. At peak mosquito season, the number of female mosquitoes was 95.5% lower (95% CI, 93.6-96.9) in release areas compared to non-release areas, with the most geographically isolated neighborhood reaching a 99% reduction. This work demonstrates the high efficacy of mosquito SIT in an area ninefold larger than in previous similar trials, supporting the potential of this approach in public health and nuisance-mosquito eradication programs.

Prevalence of Cognitive Frailty Phenotypes and Associated Factors in a Community-Dwelling Elderly Population

OBJECTIVES

Cognitive frailty was notable target for the prevention of adverse health outcomes in future. The goal of this study was to use a population-based survey to investigate cognitive frailty phenotypes and potentially sociodemographic factors in elderly Chinese individuals.

DESIGN

Cross-sectional study.

SETTING

General community.

PARTICIPANTS

A total of 5328 elderly adults (aged 60 years or older, mean age 71.36 years) enrolled in the Shanghai study of health promotion for elderly individuals with frailty.

MEASUREMENTS

The 5-item FRAIL scale and the 3-item Rapid Cognitive Screen tools were used to assess physical frailty and cognitive impairment, including dementia or mild cognitive impairment (MCI). Physical frailty was diagnosed by limitations in 3 or more of the FRAIL scale domains and pre-physical frailty by 1-2 limitations. Subjective cognitive decline (SCD) and pre-MCI SCD, was diagnosed with two self-report measures based on memory and other cognitive domains in elderly adults.

RESULTS

Of the participating individuals, 97.17% (n= 5177, female 53.4%) were eligible. Notably, 9.67%, 41.61% and 35.20% of participants were MCI, SCD and pre-MCI SCD; 35.86% and 4.41% exhibited physical pre-frailty and frailty; and 19.86% and 6.30% exhibited reversible and potential reversible cognitive frailty. Logistic regression analyses indicated that physical frailty phenotypes were significantly associated with MCI with SCD, and pre-MCI with SCD. Older single females with a high education level were more likely to exhibit the reversible cognitive frailty; and younger elderly individuals with a middle education level were at lower risk for potentially reversible cognitive frailty.

CONCLUSIONS

The prevalence of pre-physical and reversible cognitive frailty was high in elderly individuals and age was the most significant risk factor for all types of frailty phenotypes. To promote the rapid screening protocol of cognitive frailty in community-dwelling elderly is important to find high-risk population, implement effective intervention, and decrease adverse prognosis.

Evaluation of Hamamatsu PET imaging modules for dedicated TOF-capable scanners

Time-of-flight (TOF) capability is becoming an important capability offered in both commercial and research PET scanners. Often commercial vendors and laboratory researchers develop and utilize proprietary electronics for their devices. Consequently, it is challenging for independent research groups to develop their own TOF-PET scanners. In this investigation, we tested a prototype scanner consisting of commercially available TOF-capable modules from Hamamatsu Photonics that can be used as building blocks for PET scanners. The scanner consists of a ring of 16 modules, for a total diameter of 26.7 cm. Testing demonstrated that the scanner is capable of sustaining ~1 MHz single counting rate with a peak noise equivalent count rate (NECR) of 117.5 kHz at 75.25 MBq measured with NEMA NU-4 "rat" phantom. Spatial resolution of 2.3 mm 5 mm from the center of the scanner was measured. Energy resolution of 17.2% at 511 keV was measured. Peak sensitivity of 1.28% is reported. All the measurements were performed with energy cuts from 350 to 700 keV Finally, scanner timing resolution was found to be 462 ps. Results from testing of a prototype scanner constructed using newly released TOF-capable detector modules produced by Hamamatsu demonstrated the promise for these devices to create high performance PET system with TOF capabilities.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

[Transurethral bipolar plasmakinetic prostatectomy for benign prostatic hyperplasia in high-risk and senior patients in China: a systematic review and meta-analysis]

Objective: To evaluate the effectiveness and safety of transurethral bipolar plasmakinetic prostatectomy in the treatment of benign prostatic hyperplasia in high-risk and senior patients in China. Methods: The PubMed, Cochrane Library, CBM, CNKI and WanFang databases were searched with computer for collecting relevant interventional case series from establishment dates to September 14, 2018. After quality evaluation and data extraction independently conducted by two authors, the Meta-analysis was performed using the Comprehensive Meta-analysis V2 software. Results: Eighteen studies involving 1 899 patients are included. Maximum flow rate increased to 12.28 ml/s (95%CI: 8.42-16.14), 12.88 ml/s (95%CI: 9.85-15.92) ,14.32 ml/s (95%CI: 10.47-18.18), 14.93 ml/s (95%CI: 10.19-19.67) and 20.00 ml/s (95%CI: 19.08-20.92) in 1, 3, 6, 12 and 24 months after surgery, respectively. International prostate symptom score decreased to -18.60 (95%CI: -23.20--14.00), -17.62 (95%CI: -20.21--15.03), -19.14 (95%CI: -20.70--17.59), -19.06 (95%CI: -21.53--16.60) and -22.90 (95%CI: -24.26--21.54), respectively. Quality of life decreased to -2.38 (95%CI: -4.26--0.50), -3.39 (95%CI: -4.57--2.21),-3.75 (95%CI: -4.14--3.36), -3.36(95%CI: -4.56--2.16), and -4.58(95%CI: -4.75--4.41). Post void residual decreased to -231.16 ml (95%CI: -288.30--174.01), -76.10 ml (95%CI: -116.71--35.50), -159.90 ml(95%CI: -207.21--112.59) and -87.70 ml (95%CI: -91.91--83.48). The event rate of postoperative adverse reactions all were not high. Conclusion: Transurethral bipolar plasmakinetic prostatectomy has better clinical efficacy and no obvious side effects in the treatment of benign prostatic hyperplasia in high-risk and senior patients in China.

Re-visiting the ATA 2015 sonographic guidelines - who are we missing?: A retrospective review

BACKGROUND

The American Thyroid Association published revised guidelines in 2015 on the management of differentiated thyroid cancer in adults. One of the key changes introduced in the revision proposes that diagnostic biopsy be based on ultrasound findings (i.e. size and nodule characteristics). The overall effect of these changes results in fewer nodules requiring biopsy. This study was conducted to determine if the changes to the guidelines will result in overlooked thyroid cancers, specifically malignancies with aggressive characteristics measuring between 1 and 1.49 cm.

METHODS

Patients (n = 2083) with thyroid nodules who underwent total or subtotal/hemi thyroidectomy with or without neck dissection by a single surgeon between 2006 and 2016 were retrospectively enrolled. Demographic information and nodule characteristics were collected for all patients. Ultrasonography and final pathology reports were reviewed for patients with thyroid nodules between the sizes of 1-1.49 cm (n = 155).

RESULTS

45% (n = 70) of patients with nodules between 1 and 1.49 cm were "low suspicion" nodules according to ultrasound. 47 of these nodules contained malignancies on final histopathological examination, 100% of which were of the papillary subtype. 21% (n = 10) of these malignant nodules demonstrated extrathyroidal extension and 34% (n = 16) were associated with regional metastases.

CONCLUSIONS

Reliance on sonographic patterns alone could result in missed cancer diagnoses in patients with thyroid nodules measuring between 1 and 1.49 cm. Moreover, a portion of these malignancies may be associated with aggressive features. The effect of this finding on long-term outcomes is unclear.

[Evidence-based evaluation of recent clinical practice guidelines for the diagnosis and treatment of benign prostatic hyperplasia]

Objective: To systematically evaluate the quality of clinical practice guidelines for the diagnosis and treatment of benign prostatic hyperplasia (BPH), and to compare the context of recommendations in order to provide references for clinical application. Methods: We searched databases such as the National Guideline Clearinghouse (NGC), Guidelines International Network (GIN), National Institute for Health and Clinical Excellence (NICE), Scottish Intercollegiate Guidelines Network (SIGN) and World Health Organization (WHO), PubMed, Embase, CNKI, VIP, WanFang Data, CBM, and Medlive from their establishment until August 13, 2016, to collect evidence-based guidelines and/or consensus on BPH. Method: Methodological quality of included guidelines was assessed according to the AGREE Ⅱ instrument, and differences and similarities among recommendations were compared. Results: A total of 15 guidelines were included. According to the AGREE Ⅱ instrument, the score of scope and purpose, stakeholder involvement, rigour of formulate, clarity of presentation, applicability, and editorial independence was 72%, 38%, 30%, 58%, 16%, and 40%, respectively. The recommendations of different guidelines were basically similar, only with conflicts in some areas. Conclusions: The quality of included guidelines remains to be unified, the context of them can provide valuable implications for development or improvement.

[Percutaneous biopsy of the renal masses under ultrasound: a single-center 14 years experience]

OBJECTIVE

To assess the diagnostic rate, safety and clinical application of percutaneous renal masses biopsy for advanced renal cell carcinoma patients.

METHODS

In this retrospective study, we collected the data of renal masses from the patients who underwent renal masses biopsy under ultrasound from April 2001 to December 2014 in Peking University First Hospital. A total of 75 patients who were undiagnosed or diagnosed with advanced renal cell carcinoma by the imageological method were enrolled in this study. The patient and lesion characteristics such as tumor size, pathology of tumor, histologic subtype, pathological grade, biopsied location and biopsied cores were recorded and analyzed.

RESULTS

Among all the 75 patients, biopsy was diagnostic in 64 cases (85.3%) and non-diagnostic in 11 cases (14.7%). Of the 64 diagnostic biopsies, 60 were malignant, including 37 (61.7%) renal cell carcinoma (RCC), 13 (21.7%) urothelial carcinoma and 10 (16.7%) other malignant masses. Of all the RCC subjects, 24 suffered from clear cell RCC, 5 papillary RCC, 3 collecting duct carcinomas, 1 unclassified RCC and 4 unknown subtypes. The 11 non-diagnostic biopsied samplings included inflammatory, blood and extrarenal tissue and normal renal tissue. The proportion of collecting duct carcinoma in RCC was 10.8% and the proportion of squamous carcinoma in urothelial carcinoma was 23.1%, which were both higher than the previous research findings. For the male and female groups, non-diagnostic yields were 6.5% and 30.4%, respectively (P=0.022). Of all the 75 patients, 13 renal cell carcinoma patients underwent the surgical treatment and got the results of postoperative pathology. Comparing preoperative biopsy pathological diagnosis with postoperative pathological diagnosis, we found the diagnostic correct rates for benign and malignant lesions, pathological subtype and pathological grade were 100%, 81.8% and 60%, respectively. Mild macroscopic hematuria occurred in 1 case after RMB and there were no serious complications in all the cases.

CONCLUSION

Percutaneous renal masses biopsy under ultrasound with a high diagnostic rate which can define the histologic subtype of renal cell carcinoma. With targeted therapy, more and more patients whose evaluation suggests local advanced disease or metastatic tumors adopt renal tumor biopsy to define the histologic subtype, which could avoid unnecessary surgical treatment.

[Clinical value of fluorescence in situ hybridization positive of exfoliated urothelial cells in urothelial carcinoma]

OBJECTIVE

To analyze the clinical pathologic characteristics of cases with fluorescence in situ hybridization (FISH) positive of exfoliated urothelial cells, so as to evaluate the clinical utility of FISH in the diagnosis of urothelial carcinoma (UC).

METHODS

A total of 271 cases of FISH positive in Department of Urology of Peking University First Hospital from Apr. 2012 to Sep. 2015 were recruited in this study. Retrospective analysis was made on their clinical data. For FISH analysis, labeled probes specific for chromosomes 3, 7, 17, and the p16 (9p21) gene were used to assess chromosomal abnormalities indicative of malignancy. The positive predict values (PPV) of all the techniques were analyzed.

RESULTS

Of the 271 patients, 207 cases were UC, 7 cases were non-UC, and 57 cases were benign diseases. The PPV of FISH in detecting UC was 76.4%, while the 95% confidence interval (CI) 71.3% to 81.5%. In the cohort of FISH positive, this value was similar to that of urinary cytology (PPV 86.8%, 95% CI: 78.5%-95.0%). The PPV of FISH was lower than that of cystoscopy and ureteroscopy (PPV 96.1%, 95% CI: 91.7%-100.0%). There were significant differences between this study and the PPV of FISH reported abroad (PPV 53.9%, χ²=33.048, P<0.001). Of all the UC with FISH positive, bladder cancer showed an earlier pathological stage versus renal pelvic carcinoma and ureteral carcinoma, with significance (χ²=5.894, P=0.015, and χ²=13.601, P<0.001, respectively). However, no difference was found in the size, pathological stage and pathological grade of tumors between the urinary cytology positive group and the urinary cytology negative group. The rate of high-grade UC in ureteral carcinoma of FISH positive was 92.3%, much higher than that of ureteral carcinoma reported domestically.

CONCLUSION

The PPV of FISH in detecting UC is higher relatively, with a better clinic value for Chinese patients. The ureteral carcinoma with FISH positive obtains a higher pathological grade, which is of great guiding significance for UC.

[Concurrent renal cell carcinoma and urothelial carcinoma: long-term follow-up study of 24 cases]

Objective: To investigate the clinical manifestation, diagnosis, treatment and outcome of simultaneous occurrence of renal cell carcinoma and urothelial carcinoma. Methods: Twenty-four consecutive patients with synchronous renal cell carcinoma and urothelial carcinoma treated in our center from March 2005 to December 2015 were retrospectively reviewed. Their clinical, pathological and prognostic features were evaluated. Kaplan-Meier curves were used to estimate overall survival. Results: Patient' age was range from 48 to 79 yrs (median 69.5). Fourteen patients presented with macroscopic hematuria, and 10 patients were asymptomatic. B-ultrasound, computed tomography (CT) and cystoscopy initially indicated renal cell carcinoma concurrent with ipsilateral upper urinary tract urothelial carcinoma (UTUC) in 4 cases, renal cell carcinoma concurrent with bladder tumor in 16 cases, renal cell carcinoma concurrent with both ipsilateral UTUC and bladder tumor in 1 case, renal cell carcinoma in 2 cases and ureter carcinoma in 1 case. Different treatments were performed. The median follow-up time after surgery was 22.5 months. For patients with synchronous renal cell carcinoma and bladder tumor, there was no significant survival difference between patients treated with partial nephrectomy or radical nephrectomy. During follow up, 3 patients died of renal cell carcinoma, 3 patients died of non-oncological disease and 1 patient died of ureter carcinoma. The 3-year overall survival rate was 82.7%. For patients with synchronous renal cell carcinoma and bladder tumor, there was no significant survival difference between patients treated with partial nephrectomy or radical nephrectomy (P=0.874). Conclusions: Concurrence of renal cell carcinoma and urothelial carcinoma is clinically rare. Treatments should be individualized. The prognosis for a patient with synchronous renal cell carcinoma and urothelial carcinoma is associated with the more aggressive one.

Screening of genes related with intervertebral disc disease by dynamic differential interaction network analysis

AIM

Gene expression profiles for intervertebral disc (IVD) cells treated with different osmolarities were compared to identify key genes associated with intervertebral disc diseases.

MATERIALS AND METHODS

Microarray data was downloaded from Gene Expression Omnibus (GEO) database and pre-processed using package of R. Gene co-expression was determined with Pearson correlation coefficient. Interaction networks were established with the protein-protein interaction (PPI) information obtained from Human Protein Reference Database (HPRD database) for the two conditions: isosmoticity and hyperosmosis, and then a comparative analysis was done to identify disease-related genes. The functional annotation was performed for these genes using network ontology analysis (NOA), which also confirmed the effectiveness of this method.

RESULTS

A total of 45 feature genes were obtained through comparing 7 samples treated under isosmotic conditions and 9 high osmotic conditions. Biological processes and molecular functions were then revealed by NOA.

CONCLUSIONS

A range of disease-related genes were obtained, which might serve as the potential biomarkers or drug targets. More works are needed to further elucidate their roles in the development of intervertebral disc diseases like intervertebral disc herniation.

Mosaicism in von Hippel-Lindau disease with severe renal manifestations

von Hippel-Lindau (VHL) disease is an inheritable multisystem tumor syndrome characterized by multiple benign and malignant tumors affecting multiple organs. VHL is the result of a germline mutation in the VHL tumor suppressor gene. Molecular genomic analysis routinely confirms the clinical diagnosis. However, the use of molecular diagnostic methods can often be insufficient for the detection of mosaic germline VHL mutations, making the diagnosis of some cases of VHL difficult. Here, we report the case of a VHL mosaic patient with bilateral renal lesions in the absence of other VHL-associated lesions. A VHL mutation was not originally detected by routine molecular testing. Nonetheless, the detection of a heterozygous c.194C>G (p.Ser65Trp) VHL mutation in the patient's daughter prompted further genetic assessment and eventually resulted in the finding of a mosaic c.194C>G (p.Ser65Trp) VHL mutation in the patient. The mutation rate was 18.8 ± 3.84% in peripheral leukocytes. As the frequency of VHL mosaicism remains underdetermined, the possibility of a diagnosis of mosaic VHL should be considered in patients with both typical and atypical VHL-associated manifestations.

Schwann-like cell differentiation of rat adipose-derived stem cells by indirect co-culture with Schwann cells in vitro

OBJECTIVES

Schwann cell (SC) transplantation is a promising therapy for peripheral nerve transaction, however, clinical use of SCs is limited due to their very limited availability. Adipose-derived stem cells (ADSCs) have been identified as an alternative source of adult stem cells in recent years. The aim of this study was to evaluate the feasibility of using ADSCs as a source of stem cells for differentiation into Schwann-like cells by an indirect co-culture approach, in vitro.

MATERIALS AND METHODS

Multilineage differentiation potential of the obtained ADSCs was assayed by testing their ability to differentiate into osteoblasts and adipocytes. The ADSCs were co-cultured with SCs to be induced into Schwann-like cells through proximity, using a Millicell system. Expression of typical SC markers S-100, GFAP and P75NTR of the treated ADSCs was determined by immunocytochemical staining, western blotting and RT-PCR. Myelination capacity of the differentiated ADSCs (dADSCs) was evaluated in dADSC/dorsal root ganglia neuron (DRGN) co-cultures.

RESULTS

The treated ADSCs adopted a spindle shaped-like morphology after co-cultured with SCs for 6 days. All results of immunocytochemical staining, western blotting and RT-PCR showed that the treated cells expressed S-100, GFAP and P75NTR, indications of differentiation. dADSCs could form Schwann-like cell myelin in co-culture with DRGNs. Undifferentiated ADSCs (uADSCs) did not form myelin compared to DRGNs cultured alone, but could produce neurite extension.

CONCLUSIONS

These results demonstrate that this indirect co-culture microenvironment could induce ADSCs to differentiate into Schwann-like cells in vitro, which may be beneficial for treatment of peripheral nerve injuries in the near future.

Controlled Release of Chlorhexidine Diacetate from a Porous Methacrylate System: Supercritical Fluid Assisted Foaming and Impregnation

The release of chlorhexidine diacetate (CX) from a self-curing polymeric system based on poly(ethylmethacrylate) and tetrahydrofurfurylmethacrylate (PEM/THFM) was developed in this study. Supercritical fluid assisted impregnation and foaming was employed for preparing porous CX-PEM/THFM drug release system. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) show that the crystallinity of CX significantly decreased after supercritical processing, whilst Raman spectroscopy suggested a hydrogen bonding interaction between the CX and PEM in the product. A UV-Vis dissolution study revealed that the drug release rate is almost as seven times faster in the SCF processed drug delivery system than conventional cured samples.

Synthesis of poly(sebacic anhydride)-indomethacin controlled release composites via supercritical carbon dioxide assisted impregnation

Poly(sebacic anhydride), PSA and indomethacin drug composite (DC) formulations were prepared using supercritical CO(2) (sc-CO(2)) aided mixing. The effect of the experimental temperature and sebacic acid purity on the physical properties of PSA-indomethacin DCs was investigated using a range of analytical techniques. The nature of the PSA-indomethacin interaction in composites after processing in sc-CO(2) under various conditions was investigated using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and powder X-ray diffraction (XRD) methods, respectively. The results indicate that processing at 130 degrees C of a 4:1 (w/w) ratio PSA-indomethacin mixture, renders the indomethacin amorphous and dispersed within the polymer matrix. The primary interaction between PSA and indomethacin appears to be hydrogen bonding between the carboxylic acid OH of indomethacin and the carbonyl group of PSA. In vitro dissolution studies revealed that the processed composites exhibit a substantially enhanced dissolution rate compared to the physical mixtures. Also, through the control of experimental conditions, the initial burst effect of the drug release was largely alleviated. Instead, the erosion of PSA (zero order degradation) became the dominant factor in controlling the drug release rate.

Supercritical fluid assisted impregnation of indomethacin into chitosan thermosets for controlled release applications

Supercritical carbon dioxide (sc-CO(2)) was used to impregnate indomethacin (a non-steroidal anti-inflammatory drug) into chitosan thermosets for the preparation of controlled release formulations. The products were analyzed by a range of methods including powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of the experimental temperature and pressure of the sc-CO(2) on the thermal behavior of chitosan-indomethacin drug composites (DCs) was investigated via differential scanning calorimeter (DSC). The interaction of chitosan and indomethacin after impregnation was then studied by Fourier transform infrared (FTIR) and Raman spectroscopy, respectively. Our results suggest that the supercritical fluid impregnation process results in indomethacin being amorphously dispersed within the chitosan matrix. FTIR data suggest that the aliphatic carbonyl group of indomethacin interacts with the NH(2) group of the chitosan backbone. In vitro dissolution studies (via UV-vis spectroscopy) reveal that the dissolution rate of indomethacin substantially increases after processing in sc-CO(2), particularly, under the experimental conditions 20.7 MPa and 70 degrees C.

Protective effects of extract of Ginkgo biloba (EGb 761) on nerve cells after spinal cord injury in rats

STUDY DESIGN

An experimental animal model was used to assess spinal cord injury following lateral hemitransection at thoracic spinal cord level.

OBJECTIVE

To determine whether extract of Ginkgo biloba (EGb) could have a neuroprotective effect in spinal cord injury (SCI) in rats.

SETTING

Department of Biological Sciences and Biotechnology, Tsinghua University, China.

METHODS

A total of 72 adult rats were divided randomly into three groups: the EGb group, normal saline (NS) group, and sham operation group (sham group). After thoracic spinal cord hemitransection was performed at the level of the 9th thoracic vertebra (T9), rats in the EGb group were given 100 mg/kg EGb 761 daily, while rats in the NS group received NS. The rats in the sham group only underwent laminectomy without spinal cord hemitransection. At various time points after surgery, thoracic spinal cords were sampled and sliced for histochemistry, immunohistochemistry of inducible nitric oxide synthase (iNOS), and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) of apoptotic cells.

RESULTS

Myelin staining showed that the area of cavities was small and the demyelinated zones were limited at and around the injury site of the spinal cord in the EGb group, while the area of cavities was large and the demyelinated zones were serious in the NS group. Nissl staining showed that the ratio of bilateral ventral horn neurons (transection side/uninjured side) in the EGb group was higher than that in the NS group (P<0.05). The apoptotic index and the percentage of iNOS-positive cells were lower in the EGb group than in the NS group. Furthermore, the percentage of iNOS-positive cells positively correlated with the apoptotic index (r( 2)=0.729, P<0.01) after SCI.

CONCLUSION

This study demonstrated that EGb 761 could inhibit iNOS expression and have neuroprotective effect by preventing nerve cells from apoptosis after SCI in rats.

Formation and characterization of porous indomethacin-PVP coprecipitates prepared using solvent-free supercritical fluid processing

Supercritical carbon dioxide (sc-CO2) was used to prepare coprecipitates of indomethacin (IM) and poly(vinylpyrrolidone) (PVP) with the aim to improve the dissolution rate of IM. The coprecipitates of IM and PVP at various proportions were prepared using a stirred batch reactor containing sc-CO2 as a gas saturated solution (i.e., the compressible CO2 is dissolved in the molten compound). Temperatures between 40 and 90 degrees C and pressure of 150 or 200 bar were employed. The coprecipitates prepared at 75 degrees C and 150 bar were characterized using differential scanning calorimetry (DSC), powder X-ray diffraction (PXD), scanning electron microscopy (SEM), and dissolution testing. The results suggested that IM was totally amorphous at PVP weight fraction of 0.80 and above (indeed, as a molecular composite in which the drug molecules interact with the polymer backbone). As the PVP weight fraction decreased, IM displayed an increasing amount of crystalline material. The SEM photographs of coprecipitates showed a foamed and porous structure. The dissolution rate of IM was increased by incorporation of PVP. IM and PVP at various weight fractions exhibited comparatively higher dissolution rates than that of crystalline IM alone. The sc-CO2 based process produced a solvent free, completely amorphous porous IM solid dispersion with a rapid dissolution rate.

cAMP signalling in Trypanosoma brucei

Cyclic AMP was the first second messenger to be identified. After five decades of research, much is currently known about its biological functions and clinical implications. Several components of the cAMP signalling pathways, such as the G-protein coupled receptors and the phosphodiesterases, have become sensitive and specific drug targets for a host of clinical applications. Surprisingly, very little effort has been invested so far into the study of cAMP signalling in parasites, and its significance in host/parasite interaction. Our laboratory has embarked on a study of cAMP signalling in Trypanosoma brucei. A newly identified adenylyl cyclase, GRESAG4.4B, a member of a small family of closely related genes, is being used as a model molecule for investigating the mechanisms which control cyclase activity in the T. brucei cell. On the other hand, a number of genes for different families of cAMP-specific phosphodiesterases have been identified and characterised. One enzyme, TbPDE1, is coded for by a single-copy gene. Knock-outs of this gene display an almost normal phenotype in culture, indicating that TbPDE1 is not an essential enzyme under culture conditions. A second phosphodiesterase which is being studied in detail, TbPDE2A, is clearly different from TbPDE1, and it is coded for by a member of a small gene family containing about six similar, but non-identical genes. TbPDE2A, as TbPDE1, is specific for cAMP. In its N-terminal, it contains a GAF domain which may represent an allosteric cGMP-binding site. The other members of the TbPDE2 family all exhibit strongly conserved catalytic domains, but vary widely in their N-terminal regulatory domains. With regard to downstream signalling by the cAMP generated through the interplay of adenylyl cyclases and phosphodiesterases, we have recently identified a single-copy gene (TbRSU1) which codes for a putative regulatory subunit of the cAMP-regulated protein kinase A. This protein exhibits considerable similarity with its mammalian counterparts. Immunoprecipitation co-precipitates a protein kinase activity with the characteristics of protein kinase A.

Characterization of TbPDE2A, a novel cyclic nucleotide-specific phosphodiesterase from the protozoan parasite Trypanosoma brucei

This study reports the identification and characterization of a cAMP-specific phosphodiesterase from the parasitic hemoflagellate Trypanosoma brucei. TbPDE2A is a class I phosphodiesterase. Its catalytic domain exhibits 30-40% sequence identity with those of all 11 mammalian phosphodiesterase (PDE) families, as well as with PDE2 from Saccharomyces cerevisiae, dunce from Drosophila melanogaster, and regA from Dictyostelium discoideum. The overall structure of TbPDE2A resembles that of human PDE11A in that its N-terminal region contains a single GAF domain. This domain is very similar to those of the mammalian PDE2, -5, -6, -10, and -11, where it constitutes a potential cGMP binding site. TbPDE2A can be expressed in S. cerevisiae, and it complements an S. cerevisiae PDE deletion strain. Recombinant TbPDE2A is specific for cAMP, with a K(m) of approximately 2 micrometer. It is entirely resistant to the nonselective PDE inhibitor 3-isobutyl-1-methylxanthine, but it is sensitive to trequinsin, dipyridamole, sildenafil, and ethaverine with IC(50) values of 5.4, 5.9, 9.4, and 14.2 micrometer, respectively. All four compounds inhibit proliferation of bloodstream form trypanosomes in culture, indicating that TbPDE2A is an essential enzyme.

[Frequent somatic mutations of the von Hippel-Lindau tumor suppressor gene in primary sporadic human renal clear cell carcinomas]

OBJECTIVE

To investigate the mutation of Von Hippel-Lndau (VHL) tumor suppressor gene in patients with primary sporadic human renal cell carcinoma (RCC).

METHODS

DNA samples from 20 primary sporadic renal clear carcinoma patients were analyzed by polymerase chain reaction, single strand conformational polymorphism analyses (PCR-SSCP) and direct sequencing.

RESULTS

Somatic mutations of the VHL gene were detected in 11 (55%) of the 20 clear cell renal carcinomas, including 6 deletions, 2 insertions, and 3 missense mutations. These mutations mainly occurred in the last one-third region of exon 1, 2 and 3 of the VHL gene.

CONCLUSION

The VHL gene may frequently mutate in Chinese patients with primary sporadic renal clear cell carcinoma. The VHL gene may be useful as a marker gene for the diagnosis of RCC and as a target gene for molecular therapy.

Arterial remodeling in chronic sinoaortic-denervated rats

The spontaneous variation of blood pressure is defined as "blood pressure variability" (BPV). The chronic sinoaortic-denervated (SAD) rat is a model of high BPV without sustained hypertension. Little is known about vascular remodeling in this model. In the present study, we examined blood pressure, vascular remodeling, and aortic angiotensin II concentration in chronic SAD rats in separate experiments. In experiment 1, intra-arterial blood pressure was continuously recorded in conscious unrestrained rats. The 16-week SAD rats had a significant increase in BPV and no change in the mean level of blood pressure over a 24-h period. In experiment 2, we measured structural changes of seven kinds of arteries by histologic method and computer image analysis and functional changes of thoracic aortas by isolated artery preparation. Structural remodeling after 16-week sinoaortic denervation was characterized by increase in wall thickness, wall area, and ratio of wall thickness to internal diameter, with different changes in internal diameter and external diameter in different arteries, indicating that arterial structural remodeling expresses itself mainly as vascular growth. This vascular growth might be caused by medial smooth muscle cell growth and collagen accumulation. Aortic contraction induced by norepinephrine was potentiated, whereas aortic relaxation induced by acetylcholine was attenuated after sinoaortic denervation. In experiment 3, plasma and aortic angiotensin II concentrations were determined by radioimmunoassay. The former remained unchanged, whereas the latter was significantly increased in 10-week SAD rats. It is concluded that in rats chronic sinoaortic denervation can produce vascular remodeling that might be related to increased BPV and an activated tissue renin-angiotensin system.

Influence of CCR5 promoter haplotypes on AIDS progression in African-Americans

OBJECTIVES

To test the hypothesis that the CCR5 promoter variants in HIV-1-infected African-Americans affect the rate of progression to AIDS and to determine the extent of linkage disequilibrium between the CCR5P1 allele and the CCR5 59029A variant (referred to here as CCR5-2459A), both of which have been shown independently to accelerate AIDS progression in Caucasians.

DESIGN

We used survival analysis to assess the effects of CCR5 promoter variants in HIV-1 seroincident Caucasians and African-Americans.

SUBJECTS AND METHODS

Genotypes were determined for 806 Caucasians and 1067 African-Americans, which included 700 seroconverters, enrolled in four HIV/AIDS natural history cohort studies. These genotypes were used to determine linkage and haplotypes for CCR2 and CCR5 alleles. Survival analysis was used to assess the effect of CCR2, CCR5, and CCR5 promoter haplotypes on progression to AIDS in seroincident African-Americans.

RESULTS

A survey of Caucasians and African-Americans demonstrated complete linkage disequilibrium between CCR5P1 and CCR5-2459A sites. The composite CCR5P1 haplotype (including the CCR5-2459A allele) is shown to be associated with rapid progression to AIDS endpoints in both African-American and Caucasian cohorts, but the effect is recessive in Caucasians and dominant in African-Americans. This is probably due to the presence of modulating genes or as yet unidentified polymorphisms that may differ between racial groups.

Salivary film expresses a complex, macromolecular binding site for Streptococcus sanguis

Teeth in the oral cavity are coated with a salivary film or pellicle, which lacks apparent intermolecular organization. This heterogeneous film facilitates binding of early commensal colonizing bacteria, including Streptococcus sanguis. To test the hypothesis that sufficient intermolecular organization exists in salivary films to form binding sites for S. sanguis, an in vitro model of saliva-coated teeth was probed with murine anti-idiotypical monoclonal antibodies (mAb2, anti-ids). The anti-ids were harvested from hybridomas that were developed in response to first generation murine hybridomas that produced anti-S. sanguis adhesin monoclonal antibodies (mAb1). The anti-ids (i) reacted with experimental salivary films and inhibited S. sanguis adhesion in a dose-dependent fashion. In Western blots, the anti-ids (ii) recognized a high molecular weight salivary antigen and (iii) secretory IgA (sIgA) light chain and alpha-amylase. After isolation by gel filtration from whole saliva or mixed secretory IgA and alpha-amylase, the high molecular weight component, containing amylase activity and sIgA, bound to hydroxyapatite to promote adhesion of S. sanguis. Therefore, a complex enriched in secretory immunoglobulin A and alpha-amylase forms a S. sanguis-binding site.

Streptococcus sanguis-induced platelet clotting in rabbits and hemodynamic and cardiopulmonary consequences

By mimicking hemostatic structural domains of collagen, Streptococcus sanguis (aggregation-positive phenotype; Agg+) induces platelets to aggregate in vitro. To test the hypothesis that aggregation occurs in vivo, S. sanguis (Agg+ or Agg- suspension) was infused intravenously into rabbits. The extent of hemodynamic and cardiopulmonary changes and the fate of circulating platelets were Agg+ strain dose dependent. Within 45 to 50 s of the start of infusion, 40 x 10(8) CFU of the Agg+ strain caused increased blood pressure. Thirty seconds after infusion, other changes occurred. Intermittent electrocardiographic abnormalities (13 of 15 rabbits), ST-segment depression (10 of 15 rabbits), and preventricular contractions (7 of 15 rabbits) manifested at 3 to 7 min, with frequencies dose dependent. Respiratory rate and cardiac contractility increased during this phase. Blood catecholamine concentration, thrombocytopenia, accumulation of 111Indium-labeled platelets in the lungs, and ventricular axis deviation also showed dose dependency. Rabbits were unaffected by inoculation of an Agg- strain. Therefore, Agg+ S. sanguis induced platelet aggregation in vitro. Platelet clots caused hemodynamic changes, acute pulmonary hypertension, and cardiac abnormalities, including ischemia.

A streptococcal adhesion system for salivary pellicle and platelets

A Streptococcus sanguis 133-79 adhesin identified by the monoclonal antibody 1.1 (MAb 1.1) binds both saliva-coated hydroxylapatite (sHA) and platelets. The complementary binding site(s) for the adhesin was identified by the anti-idiotypical MAb 2.1. To learn if this adhesion system, marked by the antiadhesin MAb 1.1 and anti-binding site MAb 2.1, is commonly used by strains within the sanguis group and other viridans group streptococci, 42 strains from seven species were tested. Strains that bind to both sHA and platelets use the same adhesin and binding site epitopes. Strains that do not adhere to platelets rely on other adhesin specificities to bind to sHA.

Streptococcus sanguis expresses a 150-kilodalton two-domain adhesin: characterization of several independent adhesin epitopes

Streptococcus sanguis binds to saliva-coated hydroxylapatite (sHA), an in vitro model of the enamel pellicle. To learn if more than one adhesin functions during adhesion, 12 reactive monoclonal antibodies (MAbs) were isolated by screening against both adhesive and nonadhesive strains. Two of these MAbs, 1.1 and 1.2, inhibited adhesion in a dose-dependent fashion, although maximum inhibition with either was only 37%. When these two MAbs plus a polyclonal antibody to P1-like adhesin were combined, the inhibition was additive to about 82%. These data indicated that there were at least three distinct, functional adhesion epitopes on the surface of S. sanguis. Western blot analyses of S. sanguis surface macromolecules showed antigens at 36 and 56 (with MAb 1.2), 87 and 150 (with both MAb 1.1 and MAb 1.2), and 100, 130, and 170 kDa (with anti-P1 antibody). The antigens were eluted from gels. Isolated antigens and corresponding antibodies inhibited adhesion similarly. Additivity experiments suggested the distinct epitopes were in three groups: (i) 36/56 kDa, (ii) 87/150 kDa, and (iii) 100/130/170 kDa. The 150-kDa antigen reacting with both MAbs was isolated from gels and digested with trypsin. The digestion revealed a series of tryptic bands. A band at 38 kDa reacted with MAb 1.1 whereas a band at 54 kDa reacted with MAb 1.2 in Western blot analysis, indicating two distinct adhesive epitopes on the 150-kDa antigen. These data strongly suggest that S. sanguis adhesion to sHA is maximized when several adhesin epitopes are coexpressed on surface antigens of different sizes.

Gallstones and their chemical types in relation to serum lipids and apolipoprotein levels

OBJECTIVE

To determine the profile of lipidemia in patients with gallstones and the characteristics of lipidemia in different kinds of gallstone in gallbladder for predicting high risk subjects predisposed to gallstone formation by means of some serum parameters.

METHODS

Serum lipids and apolipoproteins levels in 47 patients with stone in gallbladder (stone group) were compared with those in 19 inpatients without stone (control group). The characteristics of lipidemia in different kinds of gallbladder stones were also compared.

RESULTS

Serum apolipoprotein (Apo) A1, C2 and E levels in the stone group significantly increased as compared with the control group (P < 0.01), but there were no statistically significant differences in TC, TG, LDL-C, HDL-C, HDL-C/TC, LDL-C/HDL-C, Apo A2, B and C3 and Apo A1/Apo B levels between the stone and control groups (P > 0.05). Increased levels of serum LDL-C and Apo B and the LDL-C/HDL-C ratio (P < 0.05) were characterized as an index of cholesterol stones, while elevated levels of serum TG and Apo C2 (P < 0.05) as an index of pigment stones.

CONCLUSIONS

Serum apolipoproteins might be more sensitive parameters as compared with serum lipids in distinguishing patients with stones from subjects without stones. There are different profiles of serum lipids and apolipoproteins in different chemical types of gallbladder stones.