[Safety of umeclidinium/vilanterol in Chinese patients in a real-world setting: a prospective, multicenter, single-arm, observational study].

Objective: To evaluate the safety of umeclidinium/vilanterol in Chinese participants in a real-world setting. Methods: This was a 24-week, prospective, multicenter, single-arm, observational study that enrolled participants treated with umeclidinium/vilanterol in real-world settings from 14 sites in China from 14 December 2020 to 30 January 2022. The primary outcomes were the incidence of adverse events (AEs) and serious adverse events (SAEs) at week 24. Results: A total of 887 participants on umeclidinium/vilanterol were enrolled. The mean (±SD) age of these participants was 67.5 (±9.6) years, with more men (77.7%) enrolled. The majority of the participants (98.1%) had been diagnosed with chronic obstructive pulmonary disease, and 67.6% of them reported comorbidities. More than half of the participants (52.8%) were taking concomitant medication in addition to the study treatment. AEs were reported in 59 (6.7%) participants and were predominantly mild to moderate in severity. SAEs were reported in 21 (2.4%) participants, including 9 fatal SAEs, 10 reported non-fatal SAEs, and 2 reported both non-fatal and fatal SAEs. None of the SAEs, including the fatal events, were considered by the investigators to be related to umeclidinium/vilanterol. Adverse drug reactions (ADRs) were reported in 6 (0.7%) participants with 4 preferred terms (PTs), all of which were considered mild in severity. Of these PTs, 2 were known ADRs of umeclidinium/vilanterol. Three participants (0.3%) reported AEs that were part of serious identified/potential hazards, all of which were considered by the investigators to be unrelated to umeclidinium/vilanterol. Conclusion: The results of this study showed that umeclidinium/vilanterol was well tolerated in Chinese participants in a real-world setting and no new drug-related safety signals were observed.

Pumilio proteins utilize distinct regulatory mechanisms to achieve complementary functions required for pluripotency and embryogenesis.

Gene regulation in embryonic stem cells (ESCs) has been extensively studied at the epigenetic-transcriptional level, but not at the posttranscriptional level. Pumilio (Pum) proteins are among the few known translational regulators required for stem-cell maintenance in invertebrates and plants. Here we report the essential function of two murine Pum proteins, Pum1 and Pum2, in ESCs and early embryogenesis. Pum1/2 double-mutant ESCs display severely reduced self-renewal and differentiation, and Pum1/2 double-mutant mice are developmentally delayed at the morula stage and lethal by embryonic day 8.5. Remarkably, Pum1-deficient ESCs show increased expression of pluripotency genes but not differentiation genes, whereas Pum2-deficient ESCs show decreased pluripotency markers and accelerated differentiation. Thus, despite their high homology and overlapping target messenger RNAs (mRNAs), Pum1 promotes differentiation while Pum2 promotes self-renewal in ESCs. Pum1 and Pum2 achieve these two complementary aspects of pluripotency by forming a negative interregulatory feedback loop that directly regulates at least 1,486 mRNAs. Pum1 and Pum2 regulate target mRNAs not only by repressing translation, but also by promoting translation and enhancing or reducing mRNA stability of different target mRNAs. Together, these findings reveal distinct roles of individual mammalian Pum proteins in ESCs and their essential functions in ESC pluripotency and embryogenesis.

[Construction of zebrafish models for screening intracranial hemorrhage associated genes].

Objective: To construct zebrafish models for the screening of intracranial hemorrhage (ICH) associated genes. Methods: ICH zebrafish models were constructed through morpholino oligonucleotides (MOs) technique and microinjection technique, and multiple verification was performed from macro and micro perspectives. First, the normal wild-type AB strain zebrafish injected with control MO was used as the control group, and AB zebrafish embryos microinjected with MOs of genes related to development of neural crest-derived cells (NCDCs) were used as the study group, such as col8a1 MO, tfap2α MO, msx1a MO, msx2 MO, and dkk1a MO. Preliminary verification of the model was conducted under a white-light optical microscope. Then, the model was verified by Tg (flk1: gfp; gata1: dsRed) double transgenic zebrafish, with vascular endothelial cells labeled by green fluorescent protein (GFP) and red blood cell labeled by fluorescent protein (dsRed), and thus the location of cerebral hemorrhage can be observed more clearly. Specifically, zebrafish embryos were microinjected with Control MO as the control group and those microinjected with col8a1 MO as the study group. Then the embryos were cultured until 48 hours post-fertilization to observe the leakage of red blood cells under the confocal laser scanning microscope. Finally, Tg (flk1: gfp) transgenic zebrafish was used to verify the model based on the blood-brain barrier (BBB). Through the leakage of dextran-rhodamine and DAPI dyes, the destruction of BBB and the occurrence of cerebral hemorrhage in zebrafish were further clarified, and quantitative statistics were carried out to verify the relationship between NCDCs development related genes and cerebral hemorrhage phenotype, which proved that the modeling was effective. Results: The zebrafish with col8a1, tfap2α, and msx1 mutations in the study group had apparent ICH compared with wildtype zebrafish, and the prevalence of ICH was 18.18% (52/286), 23.04% (62/251), and 35.94% (23/64), respectively. While, the zebrafish with msx2 and dkk1a mutations rarely had ICH, with the ICH prevalence of 1.03% (1/97) and 1.15% (1/87), respectively. The prevalence of red blood cells leakage in Tg (flk1:gfp; gata1:dsred) double transgenic zebrafish injected with Control Mo and col8a1 Mo was 0.37% (1/273) and 18.18% (52/286) (P<0.001). The number of DAPI positive nuclei of Tg (flk1: gfp) transgenic zebrafish injected with Control Mo and col8a1 Mo was 10.05±5.27 and 60.35±3.96 (P<0.001), and the fluorescent intensity of midbrain parenchymal induced by dextran-rhodamin leakage was 2.54±4.70 and 5.13±3.52 (P<0.001). Conclusion: This study successfully constructs the ICH zebrafish models, and ICH-related genes are screened out, such as col8a1, tfap2α, msx1, and so on.

[Clinical value of p16INK4a immunocytochemistry in cervical cancer screening].

Objective: To evaluate the value of p16INK4a detected by p16INK4a immunostaining as a new generation of cervical cytology for primary screening and secondary screening in population-based cervical cancer screening, and in improving cytological diagnosis. Methods: Between 2016 and 2018, 5 747 non-pregnant women aged 25-65 years with sexual history were recruited and underwent cervical cancer screening via high-risk (HR)-HPV/liquid-based cytological test (LCT) test in Shenzhen and surrounding areas. All slides were immuno-stained using p16INK4a technology, among them, 902 cases were offered p16INK4a detection during primary screening, and the remaining 4 845 cases were called-back by the virtue of abnormal HR-HPV and LCT results for p16INK4a staining. Participants with complete LCT examination, HR-HPV test, p16INK4a staining and histopathological examination results were included in this study. The performance of p16INK4a in primary and secondary screening, and in assisting cytology to detect high grade squamous intraepithelial lesion [HSIL, including cervical intraepithelial neoplasia (CIN) Ⅱ or Ⅲ] or worse [HSIL (CIN Ⅱ)+ or HSIL (CIN Ⅲ)+] were analyzed. Results: (1) One-thousand and ninety-seven cases with complete data of p16INK4a and histology were included. Pathological diagnosis: 995 cases of normal cervix, 37 cases of low grade squamous intraepithelial lesion (LSIL), 64 cases of HSIL and one case of cervical cancer were found. Among them, 65 cases of HSIL (CIN Ⅱ)+ and 34 cases of HSIL (CIN Ⅲ)+ were detected. The positive rate of p16INK4a in HSIL (CIN Ⅱ)+ was higher than that in CINⅠ or normal pathology (89.2% vs 10.2%; P<0.01). (2) p16INK4a as primary screening for HSIL (CIN Ⅱ)+ or HSIL (CIN Ⅲ)+ was equally sensitive to primary HR-HPV screening (89.2% vs 95.4%, 94.1% vs 94.1%; P>0.05), but more specific than HR-HPV screening (89.8% vs 82.5%, 87.7% vs 80.2%; P<0.05). p16INK4a was equally sensitive and similarly specific to cytology (≥LSIL; P>0.05). (3) The specificity of LCT adjunctive p16INK4a for detecting HSIL (CIN Ⅱ)+ or HSIL (CIN Ⅲ)+ were higher than that of LCT alone or adjunctive HR-HPV (P<0.01), while the sensitivity were similar (P>0.05). (4) p16INK4a staining as secondary screening: p16INK4a was significantly more specific (94.1% vs 89.7%, 91.9% vs 87.4%; P<0.01) and comparably sensitive (84.6% vs 90.8%, 88.2% vs 91.2%; P>0.05) to cytology for triaging primary HR-HPV screening. HPV 16/18 to colposcopy and triage other HR-HPV with p16INK4a was equally sensitive (88.2% vs 94.1%; P=0.500) and more specific (88.3% vs 83.0%; P<0.01) than HPV 16/18 to colposcopy and triage other HR-HPV with LCT≥ atypical squamous cells of undetermined significance (ASCUS), and the referral rate decreased (14.0% vs 19.4%; P=0.005). Conclusions: For primary screening, p16INK4a is equally specific to cytology and equally sensitive to HR-HPV screening. p16INK4a alone could be an efficient triage after primary HR-HPV screening. In addition, p16INK4a immunostaining could be used as an ancillary tool to cervical cytological diagnosis, and improves its accuracy in cervical cancer screening.

[The value of p16(INK4a) cytology for early diagnosis of cervical cancer].

Objective: To investigate the use of p16(INK4a) immuno-stained cytology as the primary screening for cervical cancer prevention. Methods: From March to August 2018, 902 women from Shenzhen and surrounding area were recruited for cervical cancer screening with ThinPrep Cytologic Test (TCT), cobas4800 HPV test, and p16(INK4a) co-test. Colpo/biopsies were performed using the point of interest biopsy protocol of directed and random cervical biopsies plus endocervical curettage for all women, any of whose tests was positive. Two senior cytopathologists interpreted TCT and p16(INK4a) test. The performance of p16(INK4a) for early detection of CIN2+ and inter-observer reproducibility of the interpretation of p16(INK4a) were evaluated. Results: The positive rates of HPV test, p16(INK4a) co-test and TCT diagnosed as LSIL/AGC or higher grade were 8.1% (73/902), 6.8% (61/902) and 4.7% (42/902), respectively. Colposcopy referring rate was 79.6% (109/137), among which 10 cases were diagnosed as CIN2+ (5 cases of CIN2 and 5 cases of CIN3). The sensitivity and specificity for CIN2+ of p16(INK4a) test, TCT (LSIL/AGC or higher grade) and HPV test were 90.0%, 80.0%, 100.0% and 90.9%, 91.9%, 82.5%, respectively. Compared to TCT and HPV test, there was no significant difference in sensitivity and specificity between p16(INK4a) and TCT/HPV test (P>0.05). The Kappa value of the 2 cytopathologists in interpreting p16(INK4a) and TCT was 0.944 and 0.425, respectively (P<0.05). Conclusions: p16(INK4a) for cervical cancer screening is equally sensitive to HPV test and specific to TCT while subjective difference of cytopathologists' interpretation of p16(INK4a) is small. Therefore, p16(INK4a) can be used as a new cervical cancer screen method for its better diagnostic performance.

Comparison between irradiating and autoclaving citrus wastes as substrate for solid-state fermentation by Aspergillus aculeatus.

Agricultural or food processing wastes cause serious environmental burden and economic losses. Solid-state fermentation using these wastes is an attractive option to valorize these wastes. However, conventional autoclaving of substrate may degrade nutrients and generate toxins. Unsterilization of the substrate will cause undesired microbial contamination. Therefore, we compared irradiation with autoclaving to treat citrus wastes as substrate for solid-state fermentation by Aspergillus aculeatus. By comparing microbial growth, enzymes tested and medium consumption, irradiated substrate had higher biomass and extracellular protein, more sugar consumption and higher enzyme production than those with autoclaved substrate. Irradiation prevented the generation of cell-inhibiting components such as 5-hydroxymethylfurfural (5-HMF) whereas preserved the flavonoids well that are often enzyme inducers. These findings suggest that irradiation of agricultural and food processing wastes as substrate has advantages over autoclaving for solid-state fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: This study proposes irradiation as an alternative to sterilize agricultural residues rich in nutrients and thermosensitive compounds, such as citrus wastes for fungal solid-state fermentation and production of enzymes.

[Relationship between cervical lesions and the type-specific viral load of high risk HPV reflected by the Ct value of Cobas 4800 HPV system].

Objective: To explore the relationship between cervical lesions and high risk HPV (HR-HPV) viral load reflected by the cycle threshold (Ct) values of Cobas 4800 HPV (Cobas 4800) system. Methods: From August 2016 to September 2017, 7 000 women from Shenzhen, were recruited for cervical cancer screening with Cobas 4800 system and cytology co-test. Colposcope biopsies were performed on women who were positive of HPV 16, 18, and positive of HPV types other than 16,18 with cytology [≥ atypical squamous cell of undetermined signification (ASCUS)], or HPV negative but abnormal of cytology [≥ low grade squamous intraepithelial lesion (LSIL)]. The Ct values of HPV 16, 18 and all combined other types coming from Cobas 4800 system were used as an indicator of viral load to analyze the relationship between type-specific HPV load and the cervical lesions. Results: (1) Among the 7 000 screening women, 370 cases were positive for cervical cancer screening, 325 of them underwent colposcope biopsies, and coloposcopy referred rate was 87.8% (325/370). Among 325 women undergoing cervical biopsy, pathological diagnosis was 119 cases of normal cervical cervix, 151 cases of LSIL, and 55 cases of high-grade squamous intraepithelial lesion (HSIL) and above (HSIL(+); including 53 cases of HSIL, 1 case of cervical adenocarcinoma, and 1 case of cervical squamous cell carcinoma). (2) The Ct value of HPV 16 was inversely correlated with the upgrading of the lesions (r=-0.617, P=0.000), and significant different among normal cervix,LSIL and HSIL(+) (35.4±4.5 vs 31.0±6.0 vs 26.5±4.0; F=25.537, P=0.000). There was no correlation between Ct value of HPV 18 and cervical lesions (r=-0.021, P=0.902). The Ct value of other 12 HPV types was statistically difference among normal normal cervix, HSIL(+) and cervicitis (33.0±5.3 vs 29.9±7.2 vs 29.8±5.8; F=5.087, P=0.007). Among them, LSIL and HSIL(+) were significantly lower than normal cervix (P<0.05), but there was no significant difference between LSIL and HSIL(+) (P>0.05). Conclusion: The Ct value of HPV 16 detecting in Cobas 4800 system as an indicator of virus load obviously correlates with different grades of cervical lesions, therefore could be a reference of cervical lesion existence and an indicator of lesion prognosis.

Identification of Magnolia wufengensis (Magnoliaceae) cultivars using phenotypic traits, SSR and SRAP markers: insights into breeding and conservation.

A combination of phenotypic characterization and molecular markers may provide reliable information on new plant varieties and elucidate the conservation status of rare species. Five newly developed Magnolia wufengensis cultivars, an endangered plant species endemic to Hubei Province, China, possess more distinctive phenotypes than common Magnolia cultivars. With reference to a wild species population of M. wufengensis and a population of Magnolia denudata, morphological traits of flower organs, simple sequence repeat (SSR), and sequence-related amplified polymorphism (SRAP) markers were used. In the morphological study, six traits of floral organs were investigated and their relationships were analyzed between cultivars. In the genetic study, 9 SSR primer pairs and 10 SRAP primer combinations were screened. The five cultivars maintained a high level of genetic diversity. Genetic diversity of each M. wufengensis cultivar was much lower than that of the wild population, but was slightly higher than that of the M. denudata population. Analysis of molecular variance (AMOVA) revealed that genetic variation among populations was 20% (SRAP) and 30% (SSR), which showed a high degree of genetic differentiation among populations of the five cultivars. The dendrograms illustrated a clear separation between M. wufengensis populations and outer species, and identified two major groups among cultivars. Correlation analysis indicated a good fit between the two marker systems, but a relatively low fit between morphological and genetic traits (SRAP: r = 0.60, SSR: r = 0.52). These findings provide reliable references for the application of these molecular markers in the breeding and conservation of M. wufengensis.

Postpartum pelvic floor function performance after two different modes of delivery.

This study investigated the incidences of urinary incontinence and pelvic organ prolapse as well as pelvic floor muscle strength after cesarean section and vaginal delivery. From June 2010 to July 2011, 149 puerpera in Shenzhen Hospital, Peking University, were divided into the cesarean section group (N = 66) and the vaginal delivery group (N = 83). Postpartum urinary incontinence analysis, pelvic examination, and pelvic muscle contraction analysis using the PHENIX neuromuscular therapy instrument were performed to compare urinary incontinence, pelvic organ prolapse, and pelvic floor muscle condition between the 2 groups. The incidences of urinary incontinence in the cesarean and vaginal delivery groups were 9.09% (6/66) and 16.87% (14/83), respectively (P > 0.05); the incidences of pelvic organ prolapse were 53.03% (35/66) and 86.75% (72/83), respectively (P < 0.05). There was no significant difference in pelvic muscle pressure or electrophysiological examination results between the 2 groups (P > 0.05). Hence, cesarean section has a protective effect on early postpartum pelvic organ prolapse, but the delivery modes do not differ significantly with respect to the incidence of postpartum urinary incontinence or pelvic muscle floor muscle strength.

Effect of gestational weight gain as well as rehabilitation training on postnatal pelvic muscle strength.

OBJECTIVE: The current study explored the impact of gestational weight gain on postnatal pelvic muscle strength and the effect of low-frequency electrical stimulation combined with biofeedback training on strength recovery. MATERIALS AND METHODS: A total of 126 mothers six to eight weeks after term delivery were recruited at Peking University Shenzhen Hospital from August 2010 to July 2011. According to gestational weight gain, they were divided into two groups: the < 15 kg (A) and > or = 15 kg (B) groups. Pelvic floor muscle fibre strength was determined. Target low-frequency electrical stimulation combined with biofeedback training was conducted. After training, pelvic floor muscle fiber strength was determined again for effect evaluation. RESULTS: Before training, types I and II pelvic floor muscle fiber strength of group B was noticeably lower than that of group A (p < 0.05). After rehabilitation, the pelvic floor muscle strength of both groups significantly increased (p < 0.05). However, types I and II pelvic floor muscle fiber strength of group B was still significantly lower than that of group A (p < 0.05). CONCLUSION: Gestational weight gain negatively influences pelvic floor muscles. Low-frequency electrical stimulation combined with biofeedback training improves postnatal pelvic floor muscle fiber strength. A less gestational weight increase indicates faster postnatal pelvic muscle strength recovery and a better rehabilitative effect.

Clinical and Radiographic Outcomes After Minimally Invasive Transforaminal Lumbar Interbody Fusion-Early Experience Using a Biplanar Expandable Cage for Lumbar Spondylolisthesis.

BACKGROUND: Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is a surgical technique frequently used to treat symptomatic lumbar spondylolisthesis. We aim to investigate the safety and efficacy of using a biplanar expandable cage in the treatment of symptomatic lumbar spondylolisthesis using a MIS TLIF approach. METHODS: A retrospective review of patient records was performed on patients who underwent MIS TLIF for symptomatic lumbar spondylolisthesis using the FlareHawk cage over a 12-month period. Patient demographics, as well as preoperative and postoperative clinical and radiographic outcome measures were recorded and analyzed. RESULTS: A total of 13 consecutive patients underwent MIS TLIF for symptomatic spondylolisthesis during the study period. The mean age was 60.2 ± 13.9 years, and 61.5% were female. The mean preoperative and postoperative slippage was 7.0 ± 3.0 mm and 1.0 ± 1.9 mm, respectively. The preoperative mean segmental lordosis was 5.1° ± 6.0°, mean anterior, posterior disc, and foraminal height were 9.1 ± 3.9 mm, 5.7 ± 1.5 mm, and 11.0 ± 2.0 mm, respectively. The postoperative mean segmental lordosis was 6.8° ± 4.7°, and mean anterior, posterior disc, and foraminal height were 11.4 ± 2.2 mm, 7.8 ± 1.0 mm, and 12.3 ± 1.3 mm. There was improvement in all radiographic parameters postoperatively. The mean Visual Analog Scale (VAS) back pain, VAS leg pain improved from 7.0 ± 2.9 and 5.1 ± 3.0 preoperatively to 3.1 ± 2.9 and 1.1 ± 1.7 at the latest clinic follow-up visit, respectively (P = .0081). The mean EuroQol-Five Dimensions (EQ5D) score improved from 0.37 ± 1.7 to 0.66 ± 0.23 after surgery. There was no subsidence, endplate violation, cage migration, or other implant-related complications. No patient required reoperation. CONCLUSIONS: The biplanar expandable cage is both safe and efficacious in treating symptomatic lumbar spondylolisthesis using the MIS TLIF approach. Spine surgeons should be familiar with the biplanar expandable cage technology and keep it in their armamentarium in surgical treatment of lumbar spondylolisthesis. LEVEL OF EVIDENCE: 4.

Pyrene-Functionalized Polyacetylenes: Synthesis and Photoluminescence Property.

Four pyrene-functionalized polyacetylenes were designed and prepared through a typical post-polymerization modification route, which is the highly efficient reaction between activated ester and primary anime groups. The chemical structures of the resultant polymers were characterized with multiple spectroscopic techniques and the data indicated the successful functionalization of the polyacetylenes. The introduction of the pyrene moieties into the polymer structure allowed us to investigate the interactions between the polymer backbone and side chains. For the mono-substituted polyacetylenes, both the monomer and excimer emission features of the pyrene groups could be recorded, while for the di-substituted polyacetylenes, the fluorescence from the pyrene excimer vanished and the fluorescence intensity from the pyrene monomer decreased, the fluorescence from the polymer chain predominated the emission features. The concomitant energy transfer from the pyrene monomer and excimer to poly(diphenylacetylene) backbone was associated with the underlying mechanism. In addition to the substitution modes, the linkage between the poly(diphenylacetylene) backbone and the pyrene moiety also played a significant role in the determination of the emission species. A long alkyl spacer was beneficial to the pyrene monomer emission while a short one may be helpful to the formation of the excimer and intramolecular energy transfer.

Infection with Hematodinium sp. in mud crabs Scylla serrata cultured in low salinity water in southern China.

Dinoflagellates in the genus Hematodinium are important parasites of wild marine crustaceans, but are rarely reported in waters with salinities < 11 or from cultured crustaceans. Since 2005, the mud crab Scylla serrata, which is cultured along the coast of southeastern China, has suffered from an acute epizootic locally known as 'milky disease'. The disease mainly occurrs from September to November. The clinical signs are largely similar to those of crabs suffering from bitter crab disease (BCD) or pink crab disease (PCD), which are caused by parasites of the genus Hematodinium. To determine whether Hematodinium sp. is a pathogen of milky disease, histopathological examinations of mud crab haemolymph, hepatopancreas, heart and gill were conducted. In addition, previously reported Hematodinium molecular probes were applied to infected material. The results indicate that Hematodinium sp. is at least one of the main pathogens of milky disease. The salinity in S. serrata culture ponds was < 9. To our knowledge, this is the first report showing the Hematodinium infection in a cultured crustacean in low salinity water.

Endothelial CXCR7 regulates breast cancer metastasis.

Atypical chemokine receptor CXCR7 (ACKR3) functions as a scavenger receptor for chemokine CXCL12, a molecule that promotes multiple steps in tumor growth and metastasis in breast cancer and multiple other malignancies. Although normal vascular endothelium expresses low levels of CXCR7, marked upregulation of CXCR7 occurs in tumor vasculature in breast cancer and other tumors. To investigate effects of endothelial CXCR7 in breast cancer, we conditionally deleted this receptor from vascular endothelium of adult mice, generating CXCR7(ΔEND/ΔEND) animals. CXCR7(ΔEND/ΔEND) mice appeared phenotypically normal, although these animals exhibited a modest 35±3% increase in plasma CXCL12 as compared with control. Using two different syngeneic, orthotopic tumor implant models of breast cancer, we discovered that CXCR7(ΔEND/ΔEND) mice had significantly greater local recurrence of cancer following resection, elevated numbers of circulating tumor cells and more spontaneous metastases. CXCR7(ΔEND/ΔEND) mice also showed greater experimental metastases following intracardiac injection of cancer cells. These results establish that endothelial CXCR7 limits breast cancer metastasis at multiple steps in the metastatic cascade, advancing understanding of CXCL12 pathways in tumor environments and informing ongoing drug development targeting CXCR7 in cancer.

BRCA1 deficient embryonic stem cells display a decreased homologous recombination frequency and an increased frequency of non-homologous recombination that is corrected by expression of a brca1 transgene.

BRCA1 is a nuclear phosphoprotein that has been classified as a tumor suppressor based on the fact that women carrying a mutated copy of the BRCA1 gene are at increased risk of developing breast and ovarian cancer. The association of BRCA1 with RAD51 has led to the hypothesis that BRCA1 is involved in DNA repair. We describe here the generation and analysis of murine embryonic stem (ES) cell lines in which both copies of the murine homologue of the human BRCA1 gene have been disrupted by gene targeting. We show that exogenous DNA introduced into these BRCA1 deficient cells by electroporation is randomly integrated into the genome at a significantly higher rate than in wild type ES cells. In contrast, integration of exogenous DNA by homologous recombination occurs in BRCA1 deficient cells at a significantly lower rate than in wild type controls. When BRCA1 expression is re-established at 5-10% of normal levels by introduction of a Brca1 transgene into BRCA1 deficient ES cells, the frequency of random integration is reduced to wild type levels, although the frequency of homologous recombination is not significantly improved. These results suggest that BRCA1 plays a role in determining the response of cells to double stranded DNA breaks.

Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes.

BACKGROUND/OBJECTIVES: The contemporary American diet figures centrally in the pathogenesis of numerous chronic diseases--'diseases of civilization'--such as obesity and diabetes. We investigated in type 2 diabetes whether a diet similar to that consumed by our pre-agricultural hunter-gatherer ancestors ('Paleolithic' type diet) confers health benefits. SUBJECTS/METHODS: We performed an outpatient, metabolically controlled diet study in type 2 diabetes patients. We compared the findings in 14 participants consuming a Paleo diet comprising lean meat, fruits, vegetables and nuts, and excluding added salt, and non-Paleolithic-type foods comprising cereal grains, dairy or legumes, with 10 participants on a diet based on recommendations by the American Diabetes Association (ADA) containing moderate salt intake, low-fat dairy, whole grains and legumes. There were three ramp-up diets for 7 days, then 14 days of the test diet. Outcomes included the following: mean arterial blood pressure; 24-h urine electrolytes; hemoglobin A1c and fructosamine levels; insulin resistance by euglycemic hyperinsulinemic clamp and lipid levels. RESULTS: Both groups had improvements in metabolic measures, but the Paleo diet group had greater benefits on glucose control and lipid profiles. Also, on the Paleo diet, the most insulin-resistant subjects had a significant improvement in insulin sensitivity (r = 0.40, P = 0.02), but no such effect was seen in the most insulin-resistant subjects on the ADA diet (r = 0.39, P = 0.3). CONCLUSIONS: Even short-term consumption of a Paleolithic-type diet improved glucose control and lipid profiles in people with type 2 diabetes compared with a conventional diet containing moderate salt intake, low-fat dairy, whole grains and legumes.

Role of K(+) efflux in apoptosis induced by AMPA and kainate in mouse cortical neurons.

Activation of ionotropic glutamate receptors can induce neuronal apoptosis in vitro and in vivo. We showed previously that activation of the N-methyl-D-aspartic acid (NMDA) subtype of glutamate receptors in a low Ca(2+) and low Na(+) condition induced apoptotic neuronal death, and that the K(+) efflux via NMDA receptor channels was likely a key event in NMDA-induced apoptosis. Since non-NMDA receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) and kainate receptors, are also permeable to K(+), we tested the hypothesis that stimulating K(+) efflux via non-NMDA receptor channels could induce apoptosis in cultured cortical neurons. Using a Ca(2+)-free and Na(+)-free external solution, application of kainate revealed outward membrane currents carried by K(+) efflux. In a low Ca(2+)/low Na(+) medium, a 5-h exposure to 50-500 microM AMPA in the presence of the NMDA receptor antagonist MK801 induced dose-dependent neuronal death 24 h after the onset of the insult, accompanied by intracellular K(+) reduction and caspase-3 activation. The AMPA-induced cell death was attenuated by the caspase inhibitor Z-Val-Ala-Asp(OMe)-fluoromethyl ketone (Z-VAD-FMK) and by the protein synthesis inhibitor cycloheximide. Reducing K(+) efflux by raising extracellular K(+) concentration from 5 to 25 mM attenuated AMPA-triggered cell death, the Ca(2+) channel antagonist nifedipine showed no effect on the AMPA toxicity. Kainate induced similar neuronal death sensitive to attenuation by Z-VAD-FMK or elevated extracellular K(+).We suggest that the non-NMDA receptor-mediated K(+) efflux may participate in apoptotic process and that blocking excessive K(+) efflux mediated by NMDA and non-NMDA receptors may selectively prevent neuronal apoptosis under certain pathological conditions.

Progressive degeneration of dopamine system functions after transient cerebral oligemia in rats.

A reduction in cerebral blood flow to oligemic levels was achieved in pentobarbital-anesthetized adult rats by clamping both carotid arteries (BCCA) for 60 min. To assess the extent to which the animals' dopaminergic system was affected over an increasing time span, their spontaneous locomotor activity in an unfamiliar environment and in response to the subcutaneous administration of apomorphine was tested at various times after either BCCA or sham operation. Eight to 14 days after the operation, it was possible to observe a diminished locomotor activity in response to apomorphine injection in BCCA as compared with sham-operated animals, while oral stereotypical behavior such as licking was increased. At 3 months, there was only a subtle decrease in apomorphine-induced locomotor activity, and stereotypical behavior was similar in both groups. At 7 months, the BCCA rats covered shorter distances than sham-operated controls during the habituation phase; after apomorphine injection, more stereotypic movements, such as, e.g., sniffing, were observed, and less running. Twelve months after surgery, no further differences could be observed between the two groups during the habituation phase, but the injection of apomorphine led to increased stereotypic sniffing movements, rearing and locomotor activity in BCCA animals to a greater extent than in the controls. At 12 months, sensorimotor disturbances elicited by the rota rod test, which were only transiently observed at 11 weeks and 7 months, did not appear any different from the normal age-related motor decline of the sham-operated controls. The animals' motor co-ordination in the chimney test was not significantly disturbed during the time between 7 and 12 months after surgery. At 15 months, nocturnal locomotor activities in BCCA rats were significantly decreased. In situ hybridization (ISH) histochemistry revealed decreased D1 receptor mRNA (D1RmRNA) in striatal neurons 19 months after surgery, while D2 receptor mRNA (D2RmRNA) and the neuronal number remained the same. The present results show that just as is already known for the immature rat brain, the adult rat brain, too, reacts to a transient decrease in its blood supply by appearance of long-lasting alterations in function, and that even a single oligemic episode is capable of inducing progressive dopaminergic dysfunctions and ultimately the partial loss of striatal D1RmRNA.

The industrial chemical Tinuvin 123 does not induce dopaminergic neurotoxicity in C57Bl/6 mice.

We have investigated the acute effects of systemic administration of Tinuvin 123 on nigro-striatal dopaminergic neurons in the C57Bl/6 mouse. Tinuvin 123 was administered subcutaneously (s.c.) twice, 16 h apart, at doses of 0, 2, 20 or 200 mg/kg body weight to a total of 48 male C57Bl/6 mice (12 animals/group). Seven days following the last dose the animals were decapitated and the brains removed. No deaths occurred during the study. There were no differences between the mean body weights of any of the experimental groups prior to or following Tinuvin 123 treatment. Animals treated s.c. with 2 mg/kg Tinuvin 123 exhibited no changes in striatal dopamine or metabolite concentrations compared with vehicle-treated animals. Higher doses of Tinuvin 123 (20 and 200 mg/kg) resulted in a moderate loss of striatal dopamine (31 and 38%) but concentrations of the dopamine metabolites 3,4-dihydroxyphenylacetic acid and homovanillic acid and the neurotransmitters serotonin, aspartate, gamma aminobutyric acid and glutamate were unchanged. The total number of tyrosine hydroxylase-immunoreactive neurons in the entire substantia nigra were equivalent in the vehicle- and Tinuvin 123-treated animals at all doses, thus no neuronal loss was demonstrated. In conclusion, this study demonstrates no evidence that systemic administered Tinuvin 123 induces dopaminergic neurotoxicity in C57Bl/6 mice.

1-Trichloromethyl-1,2,3,4-tetrahydro-beta-carboline increases extracellular serotonin and stimulates hydroxyl radical production in rats.

1-Trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo), a neurotoxin structurally similar to the dopaminergic neurotoxin MPTP, may be formed in humans treated with chloral hydrate or exposed to trichloroethylene, a widely used industrial solvent. Systemically administered TaClo (0.4 mg/kg, i.p.) induced an immediate and transient release of dopamine (DA) and serotonin (5-HT) measured using microdialysis. However, only 5-HT was increased significantly (area under the curve, AUC, for the 1-2 h-period following TaClo administration: 400% compared with the respective control value; 2-3 h-period: 326%). This was followed by a progressive increase in hydroxyl radical formation reflected by higher extracellular concentrations of the hydroxylate product of salicylic acid, 2,3-dihydroxybenzoic acid (AUC for the 1-2 h period following TaClo administration: 182% compared with the respective control value; 2-3 h period: 190%). In contrast, extracellular glutamate and GABA were increased 2-3 h post-injection by 64 and 51%, respectively. These data suggest that TaClo stimulates the generation of hydroxyl free radicals via an acute release of 5-HT and perhaps DA.