[Construction of a nomogram prediction model for pathological complete response (pCR) of ipsilateral supraclavicular lymph node after neoadjuvant chemotherapy for breast cancer with first diagnosis of ipsilateral supraclavicular lymph node metastasis].

Objective: To develop a predictive model for pathologic complete response (pCR) of ipsilateral supraclavicular lymph nodes (ISLN) after neoadjuvant chemotherapy for breast cancer and guide the local treatment. Methods: Two hundred and eleven consecutive breast cancer patients with first diagnosis of ipsilateral supraclavicular lymph node metastasis who underwent ipsilateral supraclavicular lymph node dissection and treated in the Breast Department of Henan Cancer Hospital from September 2012 to May 2019 were included. One hundred and forty two cases were divided into the training set while other 69 cases into the validation set. The factors affecting ipsilateral supraclavicular lymph node pCR (ispCR)of breast cancer after neoadjuvant chemotherapy were analyzed by univariate and multivariate logistic regression analyses, and a nomogram prediction model of ispCR was established. Internal and external validation evaluation of the nomogram prediction model were conducted by receiver operating characteristic (ROC) curve analysis and plotting calibration curves. Results: Univariate logistic regression analysis showed that Ki-67 index, number of axillary lymph node metastases, breast pCR, axillary pCR, and ISLN size after neoadjuvant chemotherapy were associated with ispCR of breast cancerafter neoadjuvant chemotherapy (P<0.05). Multivariate logistic regression analysis showed that the number of axillary lymph node metastases (OR=5.035, 95%CI: 1.722-14.721, P=0.003), breast pCR (OR=4.662, 95%CI: 1.456-14.922, P=0.010) and ISLN size after neoadjuvant chemotherapy (OR=4.231, 95%CI: 1.194-14.985, P=0.025) were independent predictors of ispCR of breast cancer after neoadjuvant chemotherapy. A nomogram prediction model of ispCR of breast cancer after neoadjuvant chemotherapy was constructed using five factors: number of axillary lymph node metastases, Ki-67 index, breast pCR, axillary pCR and size of ISLN after neoadjuvant chemotherapy. The areas under the ROC curve for the nomogram prediction model in the training and validation sets were 0.855 and 0.838, respectively, and the difference was not statistically significant (P=0.755). The 3-year disease-free survival rates of patients in the ispCR and non-ispCR groups after neoadjuvant chemotherapy were 64.3% and 54.8%, respectively, with statistically significant differences (P=0.024), the 3-year overall survival rates were 83.8% and 70.2%, respectively, without statistically significant difference (P=0.087). Conclusions: Disease free survival is significantly improved in breast cancer patients with ispCR after neoadjuvant chemotherapy. The constructed nomogram prediction model of ispCR of breast cancer patients after neoadjuvant chemotherapy is well fitted. Application of this prediction model can assist the development of local management strategies for the ipsilateral supraclavicular region after neoadjuvant chemotherapy and predict the long-term prognosis of breast cancer patients.

[The expression and significance of chromobox protein homolog 2 in breast cancer].

Objective: To study the relationship between the expression of Chromobox protein homolog (CBX) mRNA and the clinicopathological prognosis of breast cancer, and to investigate the possibility of Chromobox protein homolog 2 as a therapeutic target for breast cancer. Methods: First, we analyzed the mRNA expression of 8 CBX family genes by METABRIC database, and investigated the relationship between the expression of CBX2 mRNA and the clinicopathological parameters of breast cancer. Then we explored its relationship with prognosis. CBX2 siRNA was used to treat breast cancer cell lines with high expression of CBX2(SUM159 and SUM1315). The effects of knockdown of CBX20 on mRNA and protein expression and cell proliferation were observed. Results: According to the analysis of METABRIC database, among the 8 CBX genes, the most obvious increase in mRNA expression was CBX2, and 22.47% (445/1 980) of the patients showed high mRNA expression. The high expression of CBX2 was closely related to tumor histological grade and the molecular type of breast cancer (P<0.001). Compared with the low-expression group of CBX2 mRNA, the proportion of HER2 breast cancer (28.1% vs 7.5%) and Basal-like (44.5% vs 8.5%) in the high-expression group were both higher. Patients with high CBX2 expression had significantly shorter disease-free survival (DFS) and overall survival (OS). The knockdown of CBX2 by siRNA inhibited the proliferation of breast cancer cells. Conclusion: CBX2 is closely related to the prognosis of breast cancer and may be a target for breast cancer treatment.

[The influence factors of pathologic complete response of the ipsilateral supraclavicular lymph node of breast cancer after neoadjuvant chemotherapy].

Objective: To investigate the factors affecting the pathologic complete response (PCR) of the ipsilateral supraclavicular lymph node (ISLN) of breast cancer after neoadjuvant chemotherapy (NAC). Methods: A total of 178 patients with breast cancer who had primary ipsilateral supraclavicular lymph node metastasis (ISLNM), receiving NAC and subsequent ISLN dissection, were retrospectively reviewed. The single factor and multi factor analysis were carried out by the chi square test and the Logistic regression model. Results: The enrolled patients were all female, 28 to 74 years old. The rate of PCR on the ISLN was 52.2%. Single factor analysis showed that KI67 expression level (χ(2)=7.717,P=0.005), breast PCR (bPCR) (χ(2)=33.564,P<0.001), and axillary PCR (aPCR) (χ(2)=31.750, P<0.001) were associated with the ISLN PCR. Multifactor analysis showed that KI67 expression level (OR=4.096, 95%CI: 1.176-14.263, P=0.027), bPCR (OR=4.452, 95%CI: 1.894-10.461, P<0.001) and aPCR (OR=5.183, 95%CI: 1.974-13.605, P<0.001) were independent predictors of ISLN PCR. The rate of PCR on the ISLN was 90.9% in the patients with KI67>30% and simultaneous breast and axilla PCR. Conclusions: The PCR rate of the ISLN after neoadjuvant chemotherapy is higher than that of the breast and axillary PCR. The expression level of KI67, the bPCR and the aPCR are independent predictors of the PCR on the ISLN.

[The influence of lumpectomy on the axillary lymph node status of breast cancer patients].

Objective: To investigate the influence of lumpectomy on axillary lymph node status of breast cancer patients. Methods: The clinical data of 738 invasive breast cancer patients with non-palpable axillary lymph node and sentinel lymph node (SLN) biopsy from November 2011 to August 2013 in Henan Provincial Cancer Hospital were collected and retrospectively analyzed. Among them, 136 patients underwent preoperative lumpectomy (lumpectomy group) and 602 patients underwent puncture biopsy only (biopsy group). The difference of axillary lymph node status and positive ratio of SLN detected by color Doppler ultrasound were compared between these two groups. Results: Among the 738 breast cancer patients, the axillary lymph nodes of 444 (60.2%) cases could be detected by ultrasound. Among them, 92 cases belonged to lumpectomy group, significantly less than 352 cases of biopsy group (P=0.048). Among the patients with ultrasound-visible lymph nodes, the proportion of the biggest diameter of axillary lymph node >1 cm of lumpectomy group or biopsy group was 58.7% (54/92) or 52.8% (186/352), respectively, without significant difference (P=0.316). The proportion of patients with the ratio of long diameter to short diameter <2 of lumpectomy group or biopsy group was 37.0% (34/92) or 38.6% (136/352), respectively, with marginal difference (P=0.768). The positive rate of SLN of lumpectomy group or biopsy group was 23.5% (32/136) or 26.9% (162/602), respectively, without significant difference (P=0.419). The incidence rate of the ultrasound visible axillary lymph nodes of patients whose postoperative time ≤ 7 days or > 7days was 71.1% (64/90) or 60.9% (8/46), respectively, without significant difference (P=0.227). However, the positive rate of SLN of these two groups was 28.9% (26/90) and 13.0% (6/46), respectively, with significant difference (P=0.039). The number of ultrasound visible axillary lymph nodes, the biggest diameter of axillary lymph nodes and the ratio of the long diameter to short diameter <2 were substantially correlated with the positive rate of SLN (P<0.05). Conclusions: The incidence rate of ultrasound visible axillary lymph node in the patients with lumpectomy is higher than that of patients with puncture biopsy only. The positive rate of SLN of the patients with a long postoperative time is lower than that of patients with a short postoperative time, even though the axillary lymph nodes are ultrasound visible.

[Analysis of factors influencing the axillary lymph node metastasis and breast cancer-specific survival in patients with T1 breast cancer].

Objective: To investigate the predictors of axillary lymph node metastasis and the breast cancer-specific survival (BCSS) in patients with T1 breast cancer. Methods: A retrospective analysis of clinical and pathological data of 840 T1 invasive breast cancer cases between January 2009 and January 2014 in Henan Cancer Hospital was conducted.Chi square test and Logistic regression analysis were carried out to identify relevant factors of lymph node metastasis. Analysis of prognostic factors were analyzed by Log-rank test and Cox regression. Results: Among the 840 T1 breast cancer cases, positive axillary lymph nodes were found in 150 (17.9%) cases. Univariate analysis showed that tumor size, histological grade, tumor location, and HER2 status were associated with axillary lymph node status (P<0.05). Multivariate analysis showed that tumor size, histological grade, tumor location, and HER2 status were independent predictive factors of axillary lymph node metastasis (P<0.05). Log-rank test showed that tumor size, histological grade, HER2 status, partial response (PR) status and number of positive lymph nodes were important factors influencing BCSS of the patients with positive axillary lymph nodes (P<0.05). Cox analysis showed that the size of the primary tumors and the number of positive lymph nodes were independent factors affecting the BCSS of the patients(P<0.05). Conclusions: Tumor size, histological grade, tumor location and HER2 status correlated with axillary lymph nodes status of T1 breast cancer. For T1 breast cancer patients with positive axillary lymph node, more positive lymph nodes involved and smaller primary tumor correlated with worse prognosis.

[Analysis of predictive effect of Androgen receptor on the response to neoadjuvant chemotherapy in breast cancer patients].

Objective: To explore the expression of androgen receptor (AR) in the tissues as well as its association with the clinicopathological factors of primary breast cancer patients treated with neoadjuvant chemotherapy (NAC), and analyze the effect of AR in the prediction of pathologic complete response (PCR) rate. Method: A total of 668 breast cancer patients treated with NAC in Henan Cancer Hospital between March 2014 and June 2017 were retrospectively reviewed. The relationship of AR expression and clinicopathological characteristics was calculated using chi square test. Multivariate analysis using binary Logistic regression was used to analyze correlations of different factors with PCR. Result: All patients were female, with the age of 20-76 years old. AR was detected in 74.6% of tumors, and significantly correlated with hormone receptor (HR), human epidermalgrowth factor receptor-2 (HER-2), Ki-67, CK5/6, epidermal growth factor receptor (EGFR) and molecular subtypes (all P<0.05). Multivariate analysis showed that AR, HR and HER-2 were independent predictors for PCR (all P<0.05). Conclusions: The expressions of AR were more frequently in HR positive breast cancer tissues (86.7%), and lowest in triple-negative breast cancer (TNBC) group (23.2%). AR was independent predictor for PCR.

Association between matrix metallopeptidase 1 and type 2 diabetes mellitus coexisting with coronary heart disease in a Han Chinese population.

Matrix metallopeptidase 1 (MMP-1) has been reported to be involved in the coexistence of type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). We sought to examine the association between the MMP-1 gene polymorphism and coexistence of T2DM and CHD in a Han Chinese population. We extracted genomic DNA from the peripheral blood of 794 subjects, including 378 patients with coexisting T2DM and CHD and 416 healthy controls. We selected several single nucleotide polymorphisms of the MMP-1 gene and genotyped them using the MassARRAY system, before analyzing the data with Haploview 4.0 and SPSS 20.0. A statistical difference was found in the distribution of rs1799750 genotypes between the patient and control groups (P = 0.041). The frequency of the 2G/2G genotype was 44.25 and 37.0% among patients and control subjects, respectively. Moreover, the frequency of the 2G allele was 65.9% among patients and 59.6% in the control group, and this difference was found to be significant (P = 0.010). Elevated body mass index was also associated with the 2G/2G genotype. Thus, MMP-1 rs1799750 may be involved in the development of coexisting T2DM and CHD in the Han Chinese population.

Association of MYF5 and KLF15 gene polymorphisms with carcass traits in domestic pigeons (Columba livia).

Single nucleotide polymorphisms (SNPs) in the exons of the myogenic factor 5 (MYF5) and Kruppel-like factor 15 (KLF15) genes were identified and analysed by using DNA sequencing methods in 60 female domestic pigeons (Columba livia). Five SNPs (T5067A, C5084T, C5101T, T5127A and C5154G) were detected in exon 3 of MYF5 and 6 SNPs (C1398T, C1464T, G1542A, C1929T, G1965A and A2355G) were found in exon 2 of KLF15, respectively. The analysis revealed three genotypes, in which the AA genotype was dominant and the A allele showed a dominant advantage. For the MYF5 gene, the C5084T and T5127A SNP genotypes were significantly associated with carcass traits of pigeons. Within those two SNPs, the BB genotype showed relatively higher trait association values than those of AA or AB genotypes. No significant association was observed between the KLF15 SNP genotypes and carcass traits. These results indicated that the MYF5 gene is a potential major gene affecting carcass traits in domestic pigeons. The BB genotype of the C5084T and T5127A SNPs could be a potential candidate genetic marker for marker-assisted selection in pigeon.

Evaluation of the genetic diversity of Bupleurum using amplified fragment length polymorphism analysis.

Radix bupleuri (Chaihu), the dried root of the Bupleurum plant, is an important component of traditional Chinese medicine. In this study, we examined the genetic diversity of 11 Bupleurum strains, originating from 7 provinces in China, using amplified fragment length polymorphism analysis. A total of 274 polymorphic bands were obtained using 6 primer combinations, indicating a high level of polymorphism across all strains. An estimation of the relative relationships among strains revealed genetic distances ranging from 0.2183 to 0.7372, with an average of 0.4161. The 2 most closely related varieties were Bupleurum chinense DC. strains collected from Lushi, Henan, and Zhangjiakou, Hebei, with a genetic nearness of 0.2183. Hierarchical clustering divided the strains into 3 main groups, with B. falcatum L. from Hebei and Liaoning Provinces forming a cluster that diverged from that of B. smithii Wolff. and B. chinense DC. B. falcatum L. (Sandao chaihu), collected from Heze, Shandong, clustered independently of the other strains, suggesting that this strain may have been introduced from a different location or that it arose as a result of intraspecific variation. B. smithii Wolff. (Hei chaihu) was closely associated with B. scorzonerifolium Willd. (Nan chaihu) and B. chinense DC. (Bei chaihu), suggesting a common genetic origin.

Thinopyrum 7Ai-1-derived small chromatin with Barley Yellow Dwarf Virus (BYDV) resistance gene integrated into the wheat genome with retrotransposon.

Thinopyrum intermedium is a useful source of resistance genes for Barley Yellow Dwarf Virus (BYDV), one of the most damaging wheat diseases. In this study, wheat/Th. intermedium translocation lines with a BYDV resistance gene were developed using the Th. intermedium 7Ai- 1 chromosome. Genomic in situ hybridization (GISH), using a Th. intermedium total genomic DNA probe, enabled detection of 7Ai-1-derived small chromatins containing a BYDV resistance gene, which were translocated onto the end of wheat chromosomes in the lines Y95011 and Y960843. Random amplified polymorphic DNA (RAPD) analyses using 120 random 10-mer primers were conducted to compare the BYDV-resistant translocation lines with susceptible lines. Two primers amplified the DNA fragments specific to the resistant line that would be useful as molecular markers to identify 7Ai-1-derived BYDV resistance chromatin in the wheat genome. Additionally, the isolated Th. intermedium-specific retrotransposon-like sequence pTi28 can be used to identify Th. intermedium chromatin transferred to the wheat genome.

Age-and region-dependent changes in three-dimensional microstructural properties of proximal femoral trabeculae.

UNLABELLED: This study investigated regional variations in the 3D microstructure of trabecular bone in human proximal femur, with respect to aging. The results demonstrate that age-related changes in trabecular microstructure significantly varied from different sub-regions of the proximal femur. INTRODUCTION: We hypothesize that the age-related changes in trabecular bone microstructure appear to be varied from specific anatomic sub-regions of the proximal femur followed by non-uniform bone loss. The purpose of this study was therefore to explore regional variations in the 3D microstructure of trabecular bone in human proximal femur, with respect to aging. METHODS: A total of 162 trabecular bone cores from six regions of 27 femora of male cadaver donors were scanned using micro-computed tomography (micro-CT). The following microstructural parameters were calculated: bone volume fraction (BV/TV), trabecular number (Tb.N), thickness (Tb.Th) and separation (Tb.Sp), structure model index (SMI), and degree of anisotropy (DOA). RESULTS: Age-related changes in trabecular microstructure varied from different regions of the proximal femur. There was a significant decrease in bone volume fraction and an almost identical decrease in trabecular thickness associated with aging at any region. Regional analysis demonstrated a significant difference in BV/TV, Tb.Th, Tb.Sp, Tb.N and DOA between superior and inferior neck, as well as a significant difference in BV/TV, Tb.Sp, Tb.N, SMI and DOA between superior and inferior trochanter. CONCLUSIONS: Age-related changes in bone loss and trabecular microstructure within the male proximal femur are not uniform in this cadaveric population.

TGFalpha and EGFR in ovine preimplantation embryos and effects on development.

The present study aimed to assess location and relative amounts of transforming growth factor alpha (TGFalpha) and its receptor (EGFR) in ovine oocytes and preimplantation embryos by using immunohistochemical technique that was graded on a relative scale of 0-3, with 0 representing absence of staining, and 3 exhibiting prominent staining, and to evaluate the effects of TGFalpha/EGF on in vitro development of preimplantation embryos by adding different concentrations of EGF and TGFalpha to culture medium. The results showed that EGFR was abundant in cell plasma membranes in immature and mature oocytes, cumulus cells of immature cumulus-oocyte complexes (COC), fertilized oocytes and at different stages of embryo development. However, the relative amounts in inner cell mass (ICM) (1+) was less than that in trophectoderm (TE) cells (2+) at the blastocysts stage. The staining pattern for TGFalpha was a similar to EGFR. However, the staining for TGFalpha slightly increased in the fertilized oocytes (1-2+) as compared to immature and mature oocytes (1+). TGFalpha was mainly detected in the cytoplasm close to the membrane in both ICM and trophectoderm (TE) cells. The developmental rate of 8-cell stage embryos cultured with 5 ng/ml TGFalpha was increased as compared to other treatments (P<0.05). There was no significant difference in the rate of development of blastocysts cultured with 5 ng/ml TGFalpha, 20 ng/ml EGF, 20 ng/ml EGF+5 ng/ml TGFalpha or the control treatment (P>0.05). In addition, there was no significant difference in the number of cells in blastocyst stage as compared with different treatments (P>0.05). However, TGFalpha alone enhanced cell survival rated (P<0.01) and reduced apoptosis. We concluded that TGFalpha can improve development of ovine preimplantation embryos at the 8-cell and blastocyst stages in vitro.

Effects of rearing systems on reproductive hormones secretion and their receptors gene expression in Xianju chickens under summer conditions.

Previous study in our lab showed that indigenous Xianju chickens from free-range system (FRS) under summer conditions had lower egg production than those from conventional cage rearing system (CRS). The objective of this study was to preliminarily determine the FRS-dependent mechanism of depressing laying performance according to determining the effect of rearing systems on reproductive hormones secretion and their receptors mRNA expression in Xianju chickens reared under summer conditions. A total of 360 indigenous Xianju chickens were randomly allocated to CRS and FRS groups, each of which included 5 replicates of 36 hens. The experiment lasted between 21 and 29 wk of age. We found that the ovarian weight, numbers of small yellow follicles, and large white follicles in the FRS group were lower than those in the CRS group (P < 0.05). Changing from CRS to FRS increased serum concentrations of prolactin and decreased serum-luteinizing hormone and progesterone levels (P < 0.05). Gene expressions in the preovulatory follicles from FRS hens were upregulated for prolactin receptor and downregulated for luteinizing hormone receptor and progesterone receptor, compared to those from CRS hens (P < 0.05). It can be concluded that changing from CRS to FRS in the current experimental conditions depressed egg production traits in Xianju chickens by inducing a synergistic activity of reproductive hormones and the gene expressions of their receptors.

MicroRNA-384 downregulates SETD8 expression to suppress cell growth and metastasis in osteosarcoma cells.

OBJECTIVE: MiR-384 was reported to be downregulated and functioned as a tumor suppressor in several cancers. However, the expression and function of miR-384 in osteosarcoma (OS) have not been investigated. In the present study, we aimed to analyze the effect and mechanism of miR-384 in the progression of OS. PATIENTS AND METHODS: Quantitative Real-time polymerase chain reaction (qRT-PCR) was used to determine the expression of miR-384 in OS tissues and cells. MTT assay, colony formation analysis, Transwell assays were performed to analyze the role of miR-384 in human OS cells. Western blotting was applied to analyze the expression of SETD8, and the luciferase reporter assay was used to assess the target gene of miR-384 in OS cells. RESULTS: We found that miR-384 was significantly lowly expressed in OS tissues and OS cell lines compared with the adjacent noncancerous tissues and normal bone cell lines, respectively. Further functional analysis indicated that up-regulation of miR-384 significantly inhibited OS cells proliferation, migration, and invasion, but down-regulation of miR-384 had the opposite effects on OS cells in vitro. Moreover, SETD8 was identified as the potential target of miR-384 using dual luciferase assay, qRT-PCR and Western blot. Finally, we observed that upregulation of SETD8 reversed the effects of overexpressing of miR-384 on the proliferation, migration, and invasion of OS. CONCLUSIONS: Our data provided the first evidence which supported the function of miR-384 as a tumor suppressor in OS by targeting SETD8.

Effects of rearing systems on laying performance, egg quality, and serum biochemistry of Xianju chickens in summer.

The objective of this study was to compare the laying performance, egg quality, and serum biochemistry of hens maintained in conventional cage rearing system (CRS), flat net-rearing system (NRS), and free range system (FRS) under summer conditions. Indigenous Xianju chickens (n = 540) were randomly allocated into cages or pens of rearing system groups, within each system there were 5 replicates with 36 hens in each replicate. The experiment lasted between 21 and 29 wk of age. Hen-day egg production (P = 0.00) and egg mass (P = 0.00) were higher in the CRS but were similar in the NRS and FRS. Lowest egg weight (P = 0.02), yolk weight (P = 0.00) and yolk ratio (P = 0.01), and feed intake (P = 0.01) were observed from the FRS, whereas lowest feed conversion ratio (FCR) was recorded from the CRS (P = 0.01). Rearing systems had negligible effect on egg quality. Serum Ca (P = 0.04) and total protein (P = 0.03) levels were found to be higher in the CRS but were lower in the FRS. Serum levels of glucose (P = 0.01), cholesterol (P = 0.00), and triglyceride (P = 0.00) in the CRS increased compared with the NRS and FRS groups, whereas serum levels of high density lipoprotein cholesterol (HDL-C; P = 0.01) in the CRS decreased. It can be concluded that under summer conditions, Xianju chickens from CRS had an advantage in terms of productivity parameters, but exhibited higher levels of serum lipids and glucose.

Clinical significance of long non-coding RNA EWSAT1 as a novel prognostic biomarker in osteosarcoma.

OBJECTIVE: Long non-coding RNA EWSAT1 (EWSAT1) has been identified as a tumor promoter in several tumors, but its prognostic values in osteosarcoma have not been reported. The purpose of this study was to explore the association between EWSAT1 expression and prognosis of osteosarcoma patients. PATIENTS AND METHODS: EWSAT1 levels were examined in 176 osteosarcoma tissues and matched normal bone tissues by qRT-PCR analysis. The associations of EWSAT1 expression with clinicopathologic variables were analyzed. The survival curves were calculated by the Kaplan-Meier method. The Cox proportional hazards regression model was used to identify independent prognostic factors with independent prognostic for overall survival (OS) and disease-free survival (DFS). RESULTS: We found that EWSAT1 levels were significantly higher in osteosarcoma tissues compared with matched non-cancerous tissues (p<0.01). The level of EWSAT1 expression was significantly associated with clinical stage (p=0.001) and distant metastasis (p=0.011). Then, Kaplan-Meier analysis showed that high EWSAT1 expression level was associated with poorer OS (p=0.0007) and DFS (p=0.0010). Furthermore, Cox multivariate analyses demonstrated that EWSAT1 expression was an independent prognostic factor for both OS (p<0.001) and DFS (p=0.001) in osteosarcoma patients CONCLUSIONS: Increased EWSAT1 expression was associated with poor outcomes in osteosarcoma patients, and EWSAT1 could serve as a potential unfavorable prognostic biomarker.

Temporal patterns of circulating leptin levels in lean and obese adolescents: relationships to insulin, growth hormone, and free fatty acids rhythmicity.

Alterations in nutritional status, such as obesity, markedly influence insulin, leptin, GH secretion, and free fatty acid (FFA) levels. We measured every hour for 24 h circulating leptin, insulin, GH, and FFA levels in lean and obese adolescents to determine: 1) the impact of adolescent obesity on the diurnal changes in leptin concentrations; and 2) the temporal relationships between the diurnal patterns of circulating leptin levels and insulin, GH, and FFA levels. During puberty, we found that the 24-h profile of circulating plasma leptin levels follows a bimodal pattern with minimal concentrations occurring early in the afternoon and a nocturnal elevation starting after midnight and culminating early morning. The time course of the diurnal variation in leptin levels in the obese adolescents was not different from that in lean controls. Of note, however, in obese girls leptin 24-h excursion and leptin night to day ratio were lower than those found in lean girls. In obese adolescents, mean GH levels varied significantly less during the day and night than lean controls. During the day, there were distinct preprandial increases and postprandial decreases in FFA levels, whereas after midnight FFA levels rose in both lean and obese adolescents. A significant positive correlation was found between mean plasma insulin levels between 0800 h and 2000 h and peak in leptin in lean and obese girls and boys (r = 0.63, P: < 0.001). Peak leptin was inversely correlated with the area under the nocturnal GH levels in all groups (r = -0.31, P: < 0.0003), whereas it was positively correlated with the nocturnal peak in FFA levels (r = 0.45, P: < 0.004). In summary, we report in obese adolescent girls a blunted relative diurnal excursion in leptin levels. This abnormal rhythmicity may, in part, explain their leptin resistance state. The nocturnal rise in leptin was paralleled by a nocturnal rise in GH and FFA levels. Additional studies are needed to test the potential link between the adipose-derived peptide and GH axis in humans.

Kinetics of absorbance and anisotropy upon excited state relaxation in the reaction center core complex of a green sulfur bacterium.

Properties of the excited states in reaction center core (RCC) complexes of the green sulfur bacterium Prosthecochloris aestuarii were studied by means of femtosecond time-resolved isotropic and anisotropic absorption difference spectroscopy at 275 K. Selective excitation of the different transitions of the complex resulted in the rapid establishment of a thermal equilibrium. At about 1 ps after excitation, the energy was located at the lowest energy transition, BChl a 835. Time constants varying between 0.26 and 0.46 ps were observed for the energy transfer steps leading to this equilibrium. These transfer steps were also reflected in changes in polarization. Our measurements indicate that downhill energy transfer towards excited BChl a 835 occurs via the energetically higher spectral forms BChl a 809 and BChl a 820. Low values of the anisotropy of about 0.07 were found in the 'two-color' measurements at 820 and 835 nm upon excitation at 800 nm, whereas the 'one-color' kinetics showed much higher anisotropies. Charge separation occurred with a time constant varying between 20 and 30 ps.

Effect of carotenoid biosynthesis inhibition on the chlorosome organization in Chlorobium phaeobacteroides strain CL1401.

We have studied the effect of the absence of carotenoids on the organization of bacteriochlorophylls (BChls) in chlorosomes of Chlorobium (Chl.) phaeobacteroides strain CL1401. Carotenoid-depleted chlorosomes were obtained by means of 2-hydroxybiphenyl-supplemented cultures. In the presence of the inhibitor, isorenieratene (Isr) and beta-Isr biosynthesis were inhibited to more than 95%, leading to an accumulation of the colorless precursor phytoene inside the chlorosomes. In addition, there was a 30-40% decrease in the baseplate BChl a content. The absorption spectrum of the carotenoid-depleted chlorosomes showed a 10 nm blue shift in the BChl e Qy absorption peak. Under reducing conditions, a decrease in the BChl a/BChl e fluorescence emission ratio was observed in carotenoid-depleted chlorosomes relative to that in control chlorosomes, caused mainly by the decrease in the BChl a content. The steady-state fluorescence emission anisotropy in the BChl e region dropped from approximately 0.24 for native chlorosomes to approximately 0.14 for carotenoid-depleted ones, indicating reorganization of BChl e. The circular dichroism (CD) signal of the carotenoid-depleted chlorosomes was increased two times in the BChl e Qy region. A simple model based on the structure proposed was used to explain the observed effects. Carotenoids might affect the angle between the direction of the BChl e Qy transition and the axis of the rod. The orientation of BChl a in the baseplate remains unchanged in carotenoid-depleted chlorosomes, although there is a partial loss of BChl a as a consequence of a decrease in the baseplate size. The carotenoids are most likely rather close to the BChls and appear to be important for the aggregate structure in Chl. phaeobacteroides.

[Development of donor cells in chicken-duck chimeric embryos].

Chicken W chromosome-specific DNA fragments were obtained after transformation, extraction, purification and digestion with EcoR I of pUGD1201. The W chromosome-specific DNA probe was a 1.2 kb insert, which was labelled by the random-technique using a Digoxigenin Labeling Kit. Chicken PGCs from a line of White Leghorns were microinjected into Maya duck blastoderms at stage X. The embryos at 6,8,9,12,16,18 days of incubation were used to study the development of chicken PGCs in the chimeric embryos. Used chicken W chromosome-specific DNA probes by in situ hybridization, development of donor cells in chicken-duck chimeric embryos were studied. In 54 chimeric embryos, there were different degrees of chimerism in the organs. The chimeric rate of the livers was the highest, which of the gonads was the lowest. It is demonstrated that somatic and germline chimeras can be yielded successfully by transferring stage X chicken blastodermal cells.