[Effect of autologous platelet-rich plasma perfusion on cytokines in uterine drainage fluid of patients with intrauterine adhesions following hysteroscopic adhesiolysis].

Objective: To investigate the effect of autologous platelet-rich plasma (PRP) perfusion on the levels of cytokines in uterine drainage fluid in patients with moderate to severe intrauterine adhesions (IUA) following hysteroscopic adhesiolysis. Methods: Thirty patients with moderate to severe IUA who underwent hysteroscopic adhesiolysis at Beijing Obstetrics and Gynecology Hospital, Capital Medical University from November 2020 to March 2021 were randomly divided into two groups: the PRP group (15 patients with placement of intrauterine-suitable balloons and PRP infusion) and the control group (15 patients with placement of intrauterine-suitable balloons only). For all patients, the channel switch was opened 48 hours after the surgery. The drainage fluid of the uterine cavity was collected using syringes through the proximal end of the drainage channel switch at 24 hours after the surgery and through the drainage channel directly at 48, 72, 96, and 120 hours after the surgery, and the levels of related cytokines including platelet-derived growth factor BB (PDGF-BB), vascular endothelial growth factor A (VEGF-A), insulin-like growth factor 1 (IGF-1) and transforming growth factor-ß1 (TGF-ß1) in the drainage fluid of the uterine cavity were evaluated, respectively. Results: (1) The changes in volumes of uterine cavity drainage fluid: the total drainage fluid volumes of the PRP group and the control group in 120 hours after the surgery were (21.8±2.9) and (22.7±2.7) ml, respectively, and there was no statistically significant difference between the two groups (t=-0.847, P>0.05). No significant differences were found in the volumes of drainage fluid between the two groups at 72, 96, and 120 hours after the surgery (all P>0.05). (2) Variation in cytokine levels in the uterine cavity drainage fluid: ① PDGF-BB: median PDGF-BB levels at 24 and 48 hours after the surgery in the PRP group (6.6 and 9.6 µg/L, respectively) were significantly higher than those in the control group (4.7 and 2.7 µg/L, respectively; all P<0.05). There were no significant differences in PDGF-BB levels between the two groups at 72, 96, and 120 hours after the surgery (all P>0.05). ② VEGF-A: median VEGF-A levels at 24 and 48 hours after the surgery in the PRP group (3.5 and 2.8 µg/L, respectively) were significantly higher than those in the control group (1.6 and 1.2 µg/L, respectively; all P<0.05). There were no significant differences in VEGF-A levels between the two groups at 72, 96, and 120 hours after the surgery (all P>0.05). ③ IGF-1: median IGF-1 level at 48 hours after the surgery in the PRP group was significantly higher than that in the control group (39.5 vs 8.6 µg/L, P<0.05). No significant differences were found in IGF-1 levels at 24, 72, 96, and 120 hours after the surgery between the two groups (all P>0.05). ④ TGF-ß1: There were no significant differences in TGF-ß1 levles between the two groups at 24, 48, 72, 96, and 120 hours after the surgery (all P>0.05). Conclusions: PRP perfusion following hysteroscopic adhesiolysis may increase the levels of PDGF-BB, VEGF-A, and IGF-1 in the uterine cavity drainage fluid, which plays a beneficial role in improving wound microvascular formation, reducing adhesion reformation, and promoting endometrial regeneration and repair.

Biological Properties of 3D-Printed Zirconia Implants with p-Cell Structures.

Research on 3-dimensional (3D) printed porous zirconia-based dental implants is still in its infancy. This study aimed to evaluate the biological responses of novel zirconia implants with p-cell structures fabricated by 3D printing. The solid zirconia samples exhibited comparable density, 3-point flexural strength, and accelerated aging properties compared to specimens prepared previously by conventional methods. Cell-based experiments showed that the p-cell structure promoted cell proliferation, adhesion, and osteogenesis-related protein expression. Mechanical tests showed that both p-cell and control implants could withstand a torque of 35 Ncm without breaking. The mean maximum breaking loads of p-cell and control implants were 1,222.429 ± 115.591 N and 1,903.857 ± 250.673 N, respectively, which were much higher than the human physiological chewing force and human mean maximum occlusal force. An animal experiment showed that the bone trabeculae around the implants were significantly thicker, more numerous, and denser in the p-cell group than in the control group. This work could provide promising guidance for further exploring 3D printing techniques for porous zirconia bionic implants in dentistry.

Utility of the DECAF score for predicting survival of patients with COPD: a meta-analysis of diagnostic accuracy studies.

OBJECTIVE: The DECAF (Dyspnea, Eosinopenia, Consolidation, Acidemia, Atrial Fibrillation) score is a widely used system for predicting the survival of patients with acute aggravation of chronic obstructive pulmonary disease (COPD). Evaluations of the predictive accuracy of DECAF have shown differing results. We performed this meta-analysis to evaluate the DECAF score as a survival predictor in patients with COPD. MATERIALS AND METHODS: We have included the studies examining the accuracy of DECAF scoring system as index test with occurrence of events (mortality and need for invasive/non-invasive ventilation) as reference standards irrespective of the study design employed, type of participants and severity of the condition. We conducted a systematic search for all studies reporting the predictive accuracy of DECAF scores in the databases of PubMed Central, Scopus, Medline, Embase, and Cochrane from inception until September 2020. We have used the quality assessment of diagnostic accuracy studies-2 (QUADAS-2) tool to evaluate the risk of bias. We used the STATA software "midas" package to perform the meta-analysis. RESULTS: We included 21 studies with 6429 patients. Most studies included were prospective. Most studies were conducted in the United Kingdom. Most studies used a cut-off value of the DECAF score ≥3 to predict the in-hospital or 30-day mortality and need for mechanical ventilation. All the studies used the occurrence of in-hospital/30-day mortality or patient undergoing mechanical ventilation as the reference standards. The pooled sensitivity and specificity of the DECAF score for predicting in-hospital mortality among patients with acute exacerbation of COPD were 74% (95% CI, 67%-79%) and 76% (95% CI, 68%-82%), respectively; and those for the 30-day mortality were 72% (95% CI, 59%-82%) and 83% (95% CI, 67%-93%), respectively. The overall quality of the studies in our meta-analysis was high. We found no significant publication biases as per Deek's test and funnel plot. CONCLUSIONS: This review has certain strengths. It is the first meta-analysis assessing the predictive utility of the DECAF score for in-hospital mortality among patients with AECOPD. Most studies included were of high quality according to the QUADAS-2 tool. Despite these strengths, our review had some limitations. We found a significant between-study variability in our analysis that can limit its value for inferring or interpreting the pooled findings. The predictive accuracy of the scoring system depends on many factors such as the ethnicity of the participants or patients, the timing of the scoring system assessment, and the AECOPD severity. We could not assess the influence of these variables in our study. Despite these shortcomings, our findings provide valuable information and important implications for the clinical practice involving patients with AECOPD. We found that the DECAF score can predict in-hospital and 30-day mortalities with satisfactory sensitivity and specificity.

Herbaceous Dominant the Changes of Normalized Difference Vegetation Index in the Transition Zone Between Desert and Typical Steppe in Inner Mongolia, China.

Asymmetric responses of aboveground net primary productivity (ANPP) to precipitation were identified as a signal to predict ecosystem state shifts at temperate grassland zones in Inner Mongolia, China. However, mechanism studies were still lacking. This study hypothesized that the enhanced growth and newly emerged herbaceous after increased precipitation resulted in the highest asymmetry at the transition zone between desert and typical steppe. We monitored the responses of the normalized difference vegetation index (NDVI) of different species to precipitation events using un-manned aerial vehicle technology to test this hypothesis. NDVI and species richness were measured twice at fixed points in July and August with a time interval of 15 days. Results showed that: (1) From July to August, NDVI in the transition zone increased significantly after precipitation (P < 0.05), but NDVI in both the desert and typical steppe showed a non-significant change (P > 0.05). (2) In the transition zone, NDVI increases from the shrub and herbaceous contributed to 37 and 63% increases of the site NDVI, respectively. (3) There was a significant difference in species richness between July and August in the transition zone (P < 0.05), mainly caused by the herbaceous (Chenopodiaceae, Composite, Convolvulaceae, Gramineae, Leguminosae, and Liliaceae), which either emerged from soil or tillers growth from surviving plants. This study demonstrated that herbaceous dominant the changes of NDVI in the transition zone, which provides a scientific basis for the mechanism studies of ANPP asymmetric response to precipitation and warrants long-term measurements.

[Quantitative study on the development of fetal ventricles and cisterna magna in second and third trimesters with MRI].

Objective: To analyze the changes of growth and development of normal fetal ventricles and cisterna magna with gestational age(GA) and the correlation with fetal gender in the second and third trimester,and establish the MR prenatal diagnosis reference standards. Methods: A total of 633 fetuses (mean GA (27.0±4.1) weeks (18.9-40.6 weeks))without central nervous system abnormalities were retrospectively collected from the Obstetrics and Gynecology Hospital of Fudan University from June 2012 to August 2017. The lateral ventricle trigonometric width (LVTW), third ventricle width (TVW), fourth ventricle width (FVW), anterior-posterior diameter of the fourth ventricle(APDFV), cavum septum pellucidum width (CSPW) and cisterna magna width (CMW) were obtained in the standard measure planes on MR image.The correlation between the biometrics and GA and the correlation between the biometrics and fetal gender were analyzed respectively, and the normal reference values of the biometrics were calculated. Spearman correlation analysis, Pearson correlation analysis,linear regression analysis, independent samples t-test and paired samples t-test were used for statistic analysis. Results: (1)Fetal LLVTW,RLVTW,TVW,CSPW and CMW in second and third trimesters were correlated with GA at medium and low levels(the correlation coefficient r were 0.311, 0.277, 0.207, 0.226, 0.295, respectively, all P<0.01). FVW and APDFV were statistically correlated with GA, and the linear regression equations were as follows: y=0.022×GA-0.043 (adjusted R(2)=0.642); y=0.018×GA-0.159 (adjusted R(2)=0.690). (2)Fetal LLVTW,RLVTW,FVW,APDFV and CSPW were not correlated with fetal gender in second and third trimesters(r=-0.078,-0.057,-0.087,-0.004 and 0.024, P=0.124,0.258,0.085,0.931 and 0.618, all P>0.05). TVW and CMW were statistically correlated with fetal gender(r=-0.310, -0.180, P=0.000, 0.006, all P<0.05). (3) The mean values of LLVTW and RLVTW were (0.71±0.13) cm and (0.68±0.13) cm, respectively, and significant difference was found between them(t=3.180, P=0.002). The mean value of CSPW was (0.59±0.15) cm. And the mean values of male and female fetuses for TVW and CMW were (0.17±0.05) cm, (0.16±0.06) cm and (0.68±0.15) cm, (0.58±0.15) cm, respectively. The corresponding prenatal MRI diagnostic criteria were as follows: LLVTW 1.1 cm, RLVTW 1.0 cm, CSPW 1.0 cm, TVW 0.3 cm, CMW (male 1.1 cm, female 1.0 cm). Conclusions: The normal fetal ventricles and cisterna magna are increased with the GA in the second and third trimesters. TVW and CMW are related to fetal gender. The establishment of normal reference values of fetal ventricles and cisterna magna based on GA and fetal gender are conducive to enhance the accuracy of MRI prenatal diagnosis.

Effect of early enteral nutrition (EN) on endotoxin in serum and intestinal permeability in patients with severe acute pancreatitis.

OBJECTIVE: This work aimed at studying the effect of early enteral nutrition (EN) on serum endotoxin and intestinal permeability in patients with severe acute pancreatitis. PATIENTS AND METHODS: 70 cases of patients with severe acute pancreatitis were cured in our hospital from April 2015 to January 2016. Patients selected were randomly divided into two groups including a group of patients having parenteral nutrition (group PN) and that had enteral nutrition (group EN). The results were assessed by: 1) the differences of serum endotoxin level; 2) the differences of the lactulose/mannitol ratio of urine, before intervention and one and two weeks after the intervention. RESULTS: Before the intervention, both groups had similar levels of serum endotoxin and the same lactulose/mannitol excretion rate of urine (p>0.05). One and two weeks after the intervention, the serum endotoxin level and the lactulose/mannitol excretion rate of urine of the group PN were significantly higher than the group EN (p<0.05). CONCLUSIONS: Compared with PN, EN has a bigger effect on serum endotoxin and intestinal permeability in patients with severe acute pancreatitis. EN can better promote the elimination of serum endotoxin and reduce intestinal permeability. Therefore, EN deserves clinical expansion.

Experimental test and life estimation of the OLED at normal working stress based on the luminance degradation model.

In order to accurately acquire the life time information for the organic light emitting diode (OLED), an experiment based on the normal stress life test was carried out to gain the data for the luminance degradation tests. The luminance degradation model of OLED was established based on the Weibull function and the least square method. Combined with luminance degradation data, Weibull parameters were estimated, the qualitative and the quantitative relationship between the initial luminance and the OLED life was obtained, and the life estimation of the product was achieved. Numerical results show that the test scheme is feasible, the luminance degradation model proves to be reliable for the OLED life estimation, and the fitting accuracy is very high by comparison with the test data fluctuation. Moreover, the real life time of the OLED is measured, which can verify the validity of the assumptions used in accelerated life test methods and provide manufacturers and customers with significant guidelines.

Renal tumours in a Tsc2(+/-) mouse model do not show feedback inhibition of Akt and are effectively prevented by rapamycin.

Tuberous sclerosis (TSC) is an inherited syndrome in which tumours in multiple organs are characterised by activation of mammalian target of rapamycin complex 1 (mTORC1). Previous work suggests that mTORC1 activation is associated with feedback inhibition of Akt, a substrate of mTORC2. This could limit TSC-associated tumour growth but lead to paradoxical promotion of tumour cell survival upon treatment with mTOR inhibitors. However, Akt/mTOR signalling has not been fully investigated in TSC-associated tumours and it has been uncertain whether mTOR inhibition can prevent TSC-associated renal tumourigenesis. In this study, we investigated Akt/mTOR signalling in renal tumours using a Tsc2(+/-) mouse model and tested whether mTOR inhibition could prevent renal tumourigenesis. We found that all renal lesions including cysts, adenomas and carcinomas exhibited activation of both Akt and mTORC1 as evidenced by increased protein expression and phosphorylation of Akt and mTOR and their downstream targets. Protein kinase Cα was also highly expressed and phosphorylated in these lesions, consistent with activation of mTORC2. Surprisingly, IRS proteins were highly expressed, in contrast to a striking decrease seen in cultured Tsc2(-/-) mouse embryonic fibroblasts, suggesting one mechanism through which loss of feedback inhibition of Akt may occur in mTORC1 hyperactivated Tsc-associated tumours. Long-term treatment with rapamycin reduced both Akt and mTORC1 activity in normal kidney tissues and blocked the development of all types of renal lesions. In conclusion, in contrast to previous studies, we found that Akt signalling is not inhibited in Tsc-associated renal lesions and that by partially inhibiting the Akt/mTOR pathway, rapamycin is highly effective in preventing Tsc-associated tumours.

mTORC1 drives HIF-1α and VEGF-A signalling via multiple mechanisms involving 4E-BP1, S6K1 and STAT3.

Recent clinical trials using rapalogues in tuberous sclerosis complex show regression in volume of typically vascularised tumours including angiomyolipomas and subependymal giant cell astrocytomas. By blocking mechanistic/mammalian target of rapamycin complex 1 (mTORC1) signalling, rapalogue efficacy is likely to occur, in part, through suppression of hypoxia-inducible factors (HIFs) and vascular endothelial growth factors (VEGFs). We show that rapamycin reduces HIF-1α protein levels, and to a lesser extent VEGF-A levels, in renal cystadenoma cells in a Tsc2+/- mouse model. We established that mTORC1 drives HIF-1α protein accumulation through enhanced transcription of HIF-1α mRNA, a process that is blocked by either inhibition or knockdown of signal transducer and activation of transcription 3 (STAT3). Furthermore, we demonstrated that STAT3 is directly phosphorylated by mTORC1 on Ser727 during hypoxia, promoting HIF-1α mRNA transcription. mTORC1 also regulates HIF-1α synthesis on a translational level via co-operative regulation of both initiation factor 4E-binding protein 1 (4E-BP1) and ribosomal protein S6 kinase-1 (S6K1), whereas HIF-1α degradation remains unaffected. We therefore proposed that mTORC1 drives HIF-1α synthesis in a multifaceted manner through 4E-BP1/eIF4E, S6K1 and STAT3. Interestingly, we observed a disconnect between HIF-1α protein levels and VEGF-A expression. Although both S6K1 and 4E-BP1 regulate HIF-1α translation, VEGF-A is primarily under the control of 4E-BP1/eIF4E. S6K1 inhibition reduces HIF-1α but not VEGF-A expression, suggesting that mTORC1 mediates VEGF-A expression via both HIF-1α-dependent and -independent mechanisms. Our work has important implications for the treatment of vascularised tumours, where mTORC1 acts as a central mediator of STAT3, HIF-1α, VEGF-A and angiogenesis via multiple signalling mechanisms.

Detection of copy number changes at the NF1 locus with improved high-resolution array CGH.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disease caused by various types of mutations in the NF1 gene. We have previously developed a locus-specific DNA microarray for detection of copy number changes at the NF1 locus by comparative genomic hybridization (CGH) analysis. The original array contains 183 probes pooled from 444 polymerase chain reaction (PCR) products. In the current work, we have used 493 probes derived from single PCR products (200--998 bp in size) to construct a higher resolution array with a smaller average probe size for molecular diagnosis of NF1. This has improved the average resolution from 12.6 kb in the previous array to 4.5 kb in the current version. The performance of the newly constructed microarray was validated with 14 well-characterized NF1 mutations for CGH analysis. These mutations represent deletions from approximately 7 kb to over 2 Mb in size. Using this array, we examined a total of 55 NF1 patients for copy number changes at the NF1 locus, detecting deletions in four of them. These results demonstrate that a locus-specific microarray constructed from single PCR products can efficiently detect copy number changes at the NF1 locus, providing a simple method for the molecular diagnosis of NF1.

Biomedical applications of chemically and microbiologically synthesized poly(glutamic acid) and poly(lysine).

This review article deals with the synthesis, physiochemical properties, and potential biomedical applications of two homo-poly amino acids. Poly-alpha-glutamic acid (alpha-PGA) and poly-alpha-lysine (alpha-PL) were synthesized by chemical synthesis. poly-gamma-glutamic acid (gamma-PGA) and poly-epsilon-lysine (epsilon-PL) were naturally occurring bio-materials that were produced by microbial fermentation. Poly(glutamic acid) (PGA) and poly(lysine) (PL) are water soluble, biodegradable, edible and nontoxic toward humans and the environment. As a result, they are suitable for various applications and have recently attracted considerable interest of the chemical industry. The distinguished features of PGA and PL also make them promising candidates for biomedical applications. The applications of PGA and PL in the areas of biomedical materials, drug delivery carriers and biological adhesives have been studied extensively and will be discussed in this review.

Determinants and distributions of plasma total homocysteine concentrations among school children in Taiwan.

BACKGROUND: Plasma total homocysteine (tHcy) level is an independent risk factor for cardiovascular disease (CVD) even among children. The purpose of this study is to evaluate the determinants and distributions of plasma tHcy levels and the relationship between plasma tHcy, folate and vitamin B12 levels among school children in Taipei. METHODS: After multi-stage sampling, we randomly selected 1234 school children (609 boys and 625 girls) with the mean age of 13 years (from 12 to 15 years) in this study. Fasting plasma tHcy levels were measured using an ABBOTT IMx analyzer (Axis Biochemicals ASA, Oslo, Norway). Plasma folate and vitamin B12 levels were measured by ACS:180 automated chemiluminescence analyzer (Bayer, Tarrytown, NY, USA). RESULTS: The distribution of plasma tHcy levels were skewed to the right with the mean values of 10.50 and 8.95 micromol/l and medians of 9.67 and 8.474 micromol/l for boys and girls, respectively. Plasma tHcy concentrations were lower in younger children and progressively increased with increasing age. Boys had significantly higher plasma tHcy levels than girls (10.50 +/- 4.134 vs. 8.95 +/- 2.61 micromol/l, p < 0.01) and lower plasma folate levels (6.05 +/- 2.85 vs. 6.39 +/- 2.58 nmol/l, p < 0.01), and vitamin B12 levels (444.8 +/- 158.4 vs. 495.0 +/- 181.5 pmol/l, p < 0.001). Plasma tHcy levels were significantly positively associated with anthropometric measures in boys; but these characteristics attenuated and became insignificant after adjusting for other potential confounders in girls. Plasma tHcy levels were negatively associated with plasma folate and vitamin B12 levels even after adjusting for BMI and other potential confounders in both genders. CONCLUSIONS: From this study, the distributions of tHcy levels were skewed to the right and the boys had higher plasma tHcy levels than girls. Plasma tHcy levels were significantly positively associated with BMI among boys. Further studies are needed to evaluate the relationship between tHcy and CVD risk factors among children for the better prevention of heart disease in early life.

Neo-centromere formation on a 2.6 Mb mini-chromosome in DT40 cells.

We describe a mammalian artificial mini-chromosome lacking human alphoid DNA and mouse minor and major satellite DNA repeats. This mini-chromosome, initially recovered in a mouse embryonic stem (ES) cell line (CGR8), is 2.6 Mb in size and consists of sequences derived from the human Y chromosome and mouse chromosomes 12 and 15. It is not stable in the CGR8 cells but replicates and segregates with high fidelity after transfer into chicken DT40 cells. Combined analysis by immunocytochemistry/fluorescence in situ hybridisation (FISH) on metaphase spreads detected an active neo-centromere on the mini-chromosome in these cells. Further analysis by immunocytochemistry/FISH on stretched chromatin allowed the localisation of the CENP-C protein to the DNA sequence derived from interval 5 of the human Y chromosome.

The accuracy of segregation of human mini-chromosomes varies in different vertebrate cell lines, correlates with the extent of centromere formation and provides evidence for a trans-acting centromere maintenance activity.

We show that the accuracy of mitotic segregation of three engineered, mapped human mini-chromosomes differs between human, mouse and chicken cell lines. We have studied the cause of these differences by analysing the extent of centromere formation on one mini-chromosome immunocytochemically. In human and chicken cell lines the mini-chromosomes segregate accurately and form centromeres but in one mouse cell line centromere formation is undetectable and mitotic segregation is inaccurate. These results indicate that the centromere is maintained by an activity that functions in trans and varies either in amount or specificity between different cells. Structurally defined mini-chromosomes may allow this activity to be studied.

Relationship between plasma leptin levels and lipid profiles among school children in Taiwan--the Taipei Children Heart Study.

Leptin, an adipose tissue-derived of gene product, is important in energy metabolism. However, the role of leptin in the metabolism of lipids is still not clear in humans. The purpose of this study was to evaluate the association of plasma leptin concentrations and lipid profiles among school children in Taiwan. After multistage sampling of 85 junior high schools in Taipei, we randomly selected 1264 children (617 boys and 647 girls) aged 12-16 years for this study. We measured the anthropometric variables, lifestyle factors and biochemical parameters among these children. Anthropometric measurements included body height (BH) and weight (BW) and we calculated body mass index (BMI) as the ratio of the BW to the square of the BH, expressed in kg/m2. Plasma leptin levels were measured by radioimmunoassay. We also measured lipid profiles including serum total cholesterol (CHOL), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), apolipoprotein-A1 (Apo-A1), apolipoprotein-B (Apo-B), and lipoprotein(a) (Lp(a)) levels, and calculated low density lipoprotein-cholesterol (LDL-C) levels and CHOL to HDL-C ratio (TCHR). Girls had higher leptin, CHOL, TG, HDL-C, (LDL-C), Apo-A1, Apo-B, and Lp(a) levels and lower BMI than boys did. Plasma leptin concentrations were significantly positively correlated with TG, LDL-C, and Apo-B, but negatively with HDL-C and Apo-A1 in both the genders. Children with higher plasma leptin levels (>75th percentiles) have significantly higher TG, HDL-C, LDL-C, TCHR, and Apo-B than those with relatively lower leptin levels. In multivariate regression analyses, the association between plasma leptin level and lipid profiles (such as CHOL, TG, and Apo-B) were still significant (p < 0.05) even after adjusting for BMI among boys. However, this association became attenuated and insignificant among girls. Finally, in the model that included the standard covariates, plasma leptin was the most predictive of CHOL, TG and Apo-B levels among those school children in Taiwan. Our results suggest that plasma leptin and BMI were independently associated with the lipids and lipoprotein profiles among Taiwanese Children. In both genders, children in the top 25% of the leptin distribution have more adverse lipid and lipoprotein profiles.

Effects of TAK-044, a nonselective endothelin receptor antagonist, on the spontaneous and indomethacin- or methylene blue-induced constriction of the ductus arteriosus in rats.

We studied the effects of TAK-044, a nonselective endothelin (ET) receptor antagonist, on the indomethacin- or methylene blue-induced constriction of the ductus arteriosus (DA) in rats and compared them with the effects on spontaneous DA constriction. Injection of TAK-044 into 21-day-old fetuses in utero was performed through the uterine wall of laparotomized mother rats under light ether anesthesia. The fetuses were autopsied 3 hr after treatment with TAK-044 (10 mg/kg) in utero and simultaneous administration to the laparotomized mother rats of indomethacin (3 mg/kg, p.o.) or methylene blue (100 mg/kg, i.p.). In the second experiment, pregnant rats were decapitated on day 21 of gestation to obtain newborn rats by cesarean delivery. Newborn rats which were given TAK-044 (2, 10 mg/kg) immediately after or 1 hr before cesarean delivery were autopsied at various times after birth. In both experiments, pups were rapidly frozen in an acetone-dry ice mixture at autopsy to evaluate the DA constriction by the whole-body freezing and shaving method. TAK-044 injection into the fetus 3 hr before autopsy completely inhibited the DA constriction induced by maternal treatment with indomethacin or methylene blue. TAK-044 caused dose-dependent inhibition of the spontaneous closure of the DA after birth. The inhibitory effect was more pronounced in pups which were given TAK-044 in utero 1 hr before birth; however, the inhibitory effect was incomplete in newborn pups. These results, together with the previous finding that BQ-123, an ETA-specific receptor antagonist, inhibits the ductal constriction induced by oxygen in vitro [Coceani et al., 1992], indicate that the ETA receptor plays a significant role in the indomethacin- or methylene blue-induced DA constriction as well as in the spontaneous DA constriction after birth, and also indicate that the inhibition of ETA receptor by TAK-044 was more easily achieved in fetuses than in neonates.

A structurally defined mini-chromosome vector for the mouse germ line.

Yeast artificial mini-chromosomes have helped to define the features of chromosome architecture important for accurate segregation and replication and have been used to identify genes important for chromosome stability and as large-fragment cloning vectors. Artificial chromosomes have been developed in human cells but they do not have defined, experimentally predictable structures. Fragments of human chromosomes have also been introduced into mice and in one case passed through the germ line. In these experiments, however, the structure and sequence organization of the fragments was not defined. Structurally defined mammalian mini-chromosome vectors should allow large tracts of DNA to be introduced into the vertebrate germ line for biotechnological purposes and for investigations of features of chromosome structure that influence gene expression. Here, we have determined the structure and sequence organization of an engineered mammalian mini-chromosome, ST1, and shown that it is stably maintained in vertebrate somatic cells and that it can be transmitted through the mouse germ line.

Underregistration of neonatal deaths: an empirical study of the accuracy of infantile vital statistics in Taiwan.

STUDY OBJECTIVE: The accuracy of the official statistic on infant deaths in Taiwan has been questioned. This study aimed to survey infant deaths nationwide, to measure associated vital statistics, and compare them with the official statistics to assess accuracy. DESIGN AND PARTICIPANTS: A nationwide survey of all gestational outcomes occurring at > or = 20 weeks' gestation over a three day study period (15-17 May 1989) was conducted to collect data from 23 counties and cities nationwide using a two stage data collection procedure. MAIN RESULTS: The survey derived infant death rate was 9.72 per 1000 live births, which was higher than the reported official statistic of 5.71 per 1000 live births. A more detailed examination of data on infant deaths showed that the estimated neonatal death rate of 6.68 per 1000 live births (95% confidence intervals: 3.33, 11.96 per 1000 live births) was significantly higher than the published official statistic of 1.94 per 1000 live births, while the postneonatal mortality of 3.04 per 1000 live births was comparable to the reported statistic of 3.37 per 1000 live births. CONCLUSIONS: This study empirically documented the underregistration of infant deaths in Taiwan, particularly those occurring during the first 27 days of life.