[Methylthioadenosine phosphorylase and p16 as surrogate diagnostic markers for CDKN2A homozygous deletion in brain tumors]

Objective: To examine whether immunohistochemistry of methylthioadenosine phosphorylase (MTAP) and p16 could be used to predict the CDKN2A status in various brain tumors. Methods: A total of 118 cases of IDH-mutant astrocytomas, 16 IDH-wildtype glioblastoma, 17 polymorphic xanthoastrocytoma (PXA) and 20 meningiomas diagnosed at Xuanwu Hospital, Capital Medical University, Beijing, China from November 2017 to October 2023 were collected and analyzed. The CDKN2A status was detected by using fluorescence in situ hybridization or next-generation sequencing. Expression of MTAP and p16 proteins was detected with immunohistochemistry. The association of loss of MTAP/p16 expression with CDKN2A homozygous/heterozygous deletion was examined. Results: Among the 118 cases of IDH-mutant astrocytoma, 13 cases showed homozygous deletion of CDKN2A. All of them had no expression of MTAP while 9 cases had no expression of p16. Among the 16 cases of IDH wild-type glioblastoma, 6 cases showed homozygous deletion of CDKN2A. All 6 cases had no expression of MTAP, while 3 of these cases had no expression of p16 expression. Among the 17 PXA cases, 4 cases showed homozygous deletion of CDKN2A, and the expression of MTAP and p16 was also absent in these 4 cases. Among the 20 cases of meningiomas, 4 cases showed homozygous deletion of CDKN2A. Their expression of MTAP and p16 was also absent. Among the four types of brain tumors, MTAP was significantly correlated with CDKN2A homozygous deletion (P<0.05), with a sensitivity of 100%. However, it was only significantly correlated with the loss of heterozygosity (LOH) of CDKN2A in astrocytomas (P<0.001). P16 was associated with CDKN2A homozygous deletion in IDH-mutant astrocytoma and PXA (P<0.001), but not with the LOH of CDKN2A. Its sensitivity and specificity were lower than that of MTAP. Conclusions: MTAP could serve as a predictive surrogate for CDKN2A homozygous deletion in adult IDH-mutant astrocytoma, PXA, adult IDH-wildtype glioblastoma and meningioma. However, p16 could only be used in the first two tumor types, and its specificity and sensitivity are lower than that of MTAP.

[Observation of visual quality after implantation of a rotational asymmetric refractive intraocular lens with a low addition region using the micromonovision design]

Objective: To investigate the effects of the application of a low addition refractive multifocal intraocular lens (IOL) using the micromonovision design in the non-dominant eye with different degrees of preset myopia on the visual acuity, visual function and visual quality after bilateral cataract surgery. Methods: In this randomized controlled trial, patients who were proposed to undergo bilateral phacoemulsification combined with rotational asymmetric refractive IOL (MF15 IOL) implantation at the First Affiliated Hospital of Zhengzhou University between September 2020 and August 2022 were included. All patients were divided into three groups using the random number method. The target refraction of the IOL in the dominant eye was 0.00 D. Non-dominant eyes were given different preoperative IOL reserve refractions, with the reserved near additional degree>0.20 D and≤0.40 D as the low addition,>0.40 D and≤0.60 D as the medium addition, and>0.60 D and≤0.80 D as the high addition. We compared uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA) and uncorrected near visual acuity (UNVA) of monocular and binocular eyes at 1 day, 1 month and 3 months postoperatively in the 3 groups of patients. Furthermore, the contrast sensitivity, stereopsis, defocus curves and visual quality questionnaire results of binocular eyes were compared at 3 months postoperatively. The statistical methods mainly used were chi-square test, two-factor repeated measures ANOVA, one-way ANOVA, LSD test, Kruskal-Wallis test, and paired t-test. Results: A total of 110 patients (220 eyes) were enrolled in the study, including 48 males and 62 females, with an average age of (59.74±9.38) years. There were 40 patients (80 eyes) in the low additional degree group, 37 patients (74 eyes) in the medium additional degree group, and 33 patients (66 eyes) in the high additional degree group. The differences in distance, intermediate and near visual acuity of the dominant eyes among the three groups were not statistically significant at different measurement timepoints postoperatively (P>0.05). The differences in intermediate and near visual acuity of the non-dominant eyes were also not statistically significant (P>0.05) among the three groups. In contrast, at 3 months, the UDVA of the non-dominant eyes in the low additional degree group (0.04±0.06) and medium additional degree group (0.04±0.07) was significantly higher than that in the high additional degree group (0.08±0.09) (F=4.776, P=0.011, bias η2=0.086). There was no statistically significant difference in binocular uncorrected distance, intermediate and near visual acuity among the three groups at different postoperative timepoints (P>0.05). The binocular UDVA, UIVA and UNVA (logMAR visual acuity) at 3 months postoperatively were -0.04±0.04, 0.03±0.08, 0.10±0.13 in the low addition group, -0.01±0.05, -0.02±0.06, 0.09±0.10 in the medium addition group, and 0.02±0.07, 0.01±0.09, 0.16±0.11 in the high addition group. At 3 months postoperatively, the binocular contrast sensitivity of the low additional degree group was significantly higher than that of the high additional degree group (P<0.05), except that there was no significant difference at the spatial frequency of 6 cycles per degree in the absence of glare (P>0.05). The binocular contrast sensitivity of the medium additional degree group was significantly higher than that of the high additional degree group at the spatial frequencies of 6 and 18 cycles per degree in the glare condition (P<0.05). The difference in the binocular contrast sensitivity between the low and medium additional degree groups did not reach statistical significance (P>0.05). The peak of the binocular defocus curve in the three groups was significantly wider than that in the monocular eyes, and the decline trend was more gentle, with no trough in the middle, and the visual acuity could be maintained above 0.2 (logMAR visual acuity) in the 0.00 D to -3.00 D defocus range. There was no significant difference in the postoperative near stereopsis results among the three groups (P>0.05), with the percentage of near stereopsis sharpness≤60″ reaching 90.00% (36/40), 89.19% (33/37) and 78.79% (26/33), respectively. The proportions of VF-14 scores≥90 in the postoperative questionnaire were 90% (36/40), 91.89% (34/37) and 81.82% (27/33) for the low, medium and high additional degree groups, respectively. The differences in the probability of photic phenomena and spectacles-independent rate were not statistically significant (P>0.05). Conclusion: The use of micromonovision design for bilateral implantation of a rotational asymmetric refractive MF15 IOL, with the non-dominant eye reserved for different near additional degrees, can enable cataract patients to have significantly improved binocular full-range vision, visual function and visual quality. When the degree of reserved near additions in the non-dominant eye preoperatively is>0.20 D and≤0.60 D, it can ensure sufficient binocular UDVA, UIVA and UNVA after surgery, and meanwhile help to obtain superior contrast sensitivity and stereopsis, as well as a satisfactory spectacles-independent rate and low incidence of photic phenomena.

The impacts of carbon emissions and voluntary carbon disclosure on firm value

Investors and other stakeholders are starting to pay attention to firms' carbon emissions and carbon disclosure. This study investigated the effects of voluntary carbon disclosure information and carbon emissions on firm value from listed companies in the Shanghai and Shenzhen 300 (CSI 300) Index. We also apply the Probit model to predict the probability of voluntary carbon disclosure information. The results indicate that the increase in carbon emissions has a negative impact on firm value. The action that companies select to disclose carbon emissions has a positive impact on firm value. The effect of leverage ratio on VCDI is increasing year by year. What is more, the probability of the average size firm carbon disclosure was 30.73% in 2020. Company management needs to pay attention to the risks caused by carbon emissions and ensure the quality of carbon disclosure information, especially the authenticity and reliability of the information.

[Contribution of central motion conduction time to the assessment of corticospinal tract lesions and its clinical significance]

Objective: To investigate the association of central motion conduction time (CMCT) with corticospinal tract lesions and its clinical application. Methods: Patients who completed transcranial magnetic stimulation-motor evoked potentials were included from Department of Neurology, Xuanwu Hospital between June 2020 and June 2021. The differences of CMCT values between corticospinal tract sign-positive group and tendon reflex-positive group and the relevant negative groups were compared. The consistency between increased CMCT values and the positive signs of corticospinal tract damage, as well as the significance of CMCT in different neurological diseases were further evaluated. Results: A total of 271 patients were included in the study, aged 12-86 (49±16) years, with 137 males (50.55%) and 134 females (49.45%). The CMCT values［M（Q₁，Q₃）］from Hoffmann's sign-positive group [9.52 (8.54, 10.99) ms vs 9.03 (8.30, 9.53) ms], Babinski's sign-positive group [19.54 (16.97, 24.43) ms vs 16.85(15.63, 18.55) ms] and tendon reflex-positive group [15.38 (9.27, 19.28) ms vs 10.49(8.79, 16.60) ms] were larger than those of relevant negative groups (all P<0.01). In the Babinski sign-positive group, 78.01%(181/232) of the patients had increased CMCT, while in the Hoffmann's sign-positive group, only 26.03%(19/73) of the patients had increased CMCT, indicating that the contribution of CMCT from the lower extremities to the assessment of corticospinal tract lesions was better than that of the upper extremities. With the increase of CMCT values in lower limbs, Babinski sign positive rate increased, the difference was statistically significant(P<0.001). In nervous system diseases, the consistency between CMCT and pathological signs was 75.65% (205/271). Conclusions: The contribution of CMCT from the lower extremities to the assessment of corticospinal tract lesions is superior to that of upper limbs. The higher increase of CMCT values are more reliable for corticospinal tract damage. CMCT has a good concordance with corticospinal tract lesions in some neurological diseases, which can be used to assist clinical diagnosis.

[Intestinal microbiome and its relationship with necrotizing enterocolitis in very low birth weight preterm infants]

Objective: To explore the composition of intestinal microflora prior to onset of necrotizing enterocolitis (NEC) in very low birth weight preterm infants. Methods: This was a multicenter prospective nested case-control study. A total of 46 very low birth weight preterm infants (birth weight <1 500 g and gestional age <35 weeks) within 24 h of life admitted into Neonatal Intensive Care Unit of Children's Hospital of Soochow University and Suzhou Municipal Hospital from April 20 to November 20, 2018 were enrolled. Baseline clinical data and fecal samples of these infants were collected. The subsequent sampling time points were 1st, 4th and 7th day in the first week of life then once per week consecutively. The endpoint of sampling was NEC occurrence, patient discharge or the 8th week post-discharge, whichever came first. Fecal samples were analyzed by 16 S rDNA high-throughput nucleotide sequencing. The control cases were infants without NEC who were matched to the NEC cases with a ratio of 1∶1. The operational taxonomic units (OTU), sequence number and shannon diversity index of the fecal samples were analyzed. Continuous variables were compared with t-test or non-parametric test, and χ² test or Fisher's exact test was used for categorical variables. Results: There were 23 patients in each group. The gestational age was (29.4±1.8) weeks in NEC group and (29.9±1.6) weeks in control group, including 13 males (57%) and 11 males (48%) in each group, respectively. Species abundance showed that the Firmicutes in both groups decreased temporarily at 7 days of age and then increased with age in control group, but not in NEC group, the Proteobacteria in both groups increased at 7 days of age and then decreased in control group, but kept increasing in NEC group. Regarding the other levels of taxonomy, compared with that of the control group, the NEC group had lower abundance of Proteobacteria, γ-proteobacteria and Enterobacteriaceae at 7 days of age, while higer abundance of Faecalibacterium at 14 days of age, meanwhile, lower Clostridium and Streptococcus at 21 days of age, lower Firmicutes, Clostridia and Clostridium perfringens and higher Proteobacteria and γ-proteobacteria at 28 days of age, these differences were all statistically significant (U=43.00, 43.00, 45.00, 80.00, 74.00, 76.00, 19.00, 8.00, 36.00, 25.00, 25.00,all P<0.05). The shannon index of NEC group was both lower than that of the controls at 21 days of age (2.4 (1.4, 3.0) vs. 3.1 (2.6, 4.0), U=67.00, P=0.027) and 28 days of age (2.4 (1.4, 2.8) vs. 3.9 (3.3, 4.2), U=12.00, P=0.001). Conclusions: The intestinal microflora profile of very low birth weight preterm infants has already changed prior to NEC development. The emergence of differential flora and the reduction of microflora diversity may facilitate early identification and prevention of NEC.

Meishan neonatal piglets tend to have higher intestinal barrier function than crossbred neonatal piglets

Meishan pigs tend to have higher disease resistance than commercial breeds, although more studies are needed to confirm this difference. This study compared intestinal barrier function between Meishan and crossbred neonatal piglets to provide guidance for both the breeding and nutritional regulation of pigs. Six Meishan piglets and 6 Duroc × (Landrace × Yorkshire) crossbred neonatal piglets (all with normal birth weights) were obtained and allocated into the MEIS and CROSS groups, respectively. Intestinal morphology, goblet cell numbers, antioxidant enzyme activity, and cytokine gene and tight junction protein expression were assessed. The results showed that BW was lower in the MEIS group than in the CROSS group (P < 0.01). The relative lengths of the duodenum (P < 0.05), jejunum (P < 0.01) and ileum (P < 0.01) in the MEIS group were higher than those in the CROSS group. Compared with the CROSS group, the MEIS group exhibited shorter villus lengths in the duodenum and jejunum (P < 0.01), a shallower crypt depth in the ileum (P < 0.001) and denser and longer microvilli in the intestine. The numbers of GCs in the duodenum (P < 0.01) and jejunum (P < 0.001) and the activity levels of glutathione peroxidase (P < 0.05) in the jejunum and of catalase (P < 0.01) and superoxide dismutase (P < 0.01) in the ileum were higher in the MEIS group than in the CROSS group. Compared with the CROSS group, the MEIS group exhibited higher gene expression levels of interleukin (IL) 4 and interferon γ (IFNγ) in the jejunum (P < 0.05); IL2 (P < 0.05), IL4 (P < 0.01) and IFNγ (P < 0.001) in the ileum; and mucin 2 (P < 0.01) and occludin (P < 0.05) in the duodenum. In conclusion, Meishan neonatal piglets showed lower birth weights but higher intestinal barrier function than crossbred piglets.

[Clinical characteristics and influencing factors of patients with novel coronavirus pneumonia combined with liver injury in Shaanxi region]

Objective: To understand the clinical characteristics, change of liver function, influencing factors and prognosis in hospitalized patients with coronavirus disease-19 (COVID-19) combined with liver injury. Methods: The general conditions, biochemical indicators of liver, blood clotting mechanism, routine blood test, UGT1A1 * 28 gene polymorphism and other data of 40 cases with COVID-19 admitted to the isolation ward of Tangdu Hospital were retrospectively analyzed. The clinical characteristics, influencing factors and prognosis of liver injury in patients with liver injury group and those with normal liver function group were compared. The mean of two samples in univariate analysis was compared by t-test and analysis of variance. The counting data was measured by χ(2) tests. The non-normal distribution measurement data were described by the median, and the non-parametric test was used. Statistically significant influencing factors were used as the independent variables in univariate analysis. Multiple logistic regression analysis was used to analyze the main influencing factors of liver injury. Results: Of the 40 cases, 25 were male (62.5%) and 15 were female (37.5%), aged 22 to 83 (53.87 ± 15.84) years. Liver injury was occurred in 22 cases (55%) during the course of the disease. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level was initially increased (4.4 to 3.5 times of the normal value) along with decrease of albumin in the second week, and the difference was statistically significant (P < 0.001). Ten cases (43.5%) had highest abnormal total blood bilirubin (54.1 μmol/ L). There was no correlation between the increase in transaminase and the increase in total blood bilirubin (R = -0.006, P = 0.972). Three cases had prothrombin activity (PTA) of ≤50%, 10 cases had elevated FDP, and 13 cases had elevated D-dimer, all of whom were severe or critically ill. Liver function injury was more likely to occur in patients who used many types of drugs and large amounts of hormones (P = 0.002, P = 0.031), and there was no correlation with the TA6TA7 mutation in the UGT1A1 * 28 gene locus. Multiple regression analysis showed that the occurrence of liver injury was only related to critical illness. The liver function of all patients had recovered within one week after conventional liver protection treatment. Conclusion: COVID-19 combined with liver function injury may be due to the slight elevation of transaminase, mostly around the second week of the disease course. Severe patients have a higher proportion of liver injury, and critical type is an independent risk factor for liver injury.

Energy Conservation and Carbon Flux Distribution During Fermentation of CO or H2/CO2 by Clostridium ljungdahlii

Both CO and H₂ can be utilized as energy sources during the autotrophic growth of Clostridium ljungdahlii. In principle, CO is a more energetically and thermodynamically favorable energy source for gas fermentation in comparison to H₂. Therefore, metabolism may vary during growth under different energy sources. In this study, C. ljungdahlii was fed with CO and/or CO₂/H₂ at pH 6.0 with a gas pressure of 0.1 MPa. C. ljungdahlii primarily produced acetate in the presence of H₂ as an energy source, but produced alcohols with CO as an energy source under the same fermentation conditions. A key enzyme activity assay, metabolic flux analysis, and comparative transcriptomics were performed for investigating the response mechanism of C. ljungdahlii under different energy sources. A CO dehydrogenase and an aldehyde:ferredoxin oxidoreductase were found to play important roles in CO utilization and alcohol production. Based on these findings, novel metabolic schemes are proposed for C. ljungdahlii growing on CO and/or CO₂/H₂. These schemes indicate that more ATP is produced during CO-fermentation than during H₂-fermentation, leading to increased alcohol production.

[Occupational activity disorders of extremely severe mass burn patients in recovery period after injury: a cross-sectional survey]

Objective: To observe the distribution of occupational activity disorders of extremely severe mass burn patients in recovery period after injury. Methods: From December 2014 to December 2015, 65 extremely severe burn patients conforming to the inclusion criteria involved in August 2 Kunshan factory aluminum dust explosion accident were admitted to Kunshan Rehabilitation Hospital. They received comprehensive rehabilitation treatment after burns, including wearing pressure clothes, ultrasound treatment, semiconductor laser and red light irradiation, motor function training, and so on. Over 2 years after injury, a cross-sectional survey was conducted on the patients' occupational activity disorders. Modified Barthel index (MBI) was used to assess the degree of activities of daily living (ADL) disorder of patients and to grade the independent level of completing each item of MBI, and then the independent level of patients completing self-care MBI items (bathing, dressing, grooming, eating, going to the toilet, urine control, and stool control) was compared with that of mobility items (going up and down stairs, bed and chair transfer, and walking). The Canadian Occupational Performance Measure (COPM) was used to assess the distribution of occupational activity disorders of patients. The distribution of the five most serious occupational activity disorders was counted, then the frequency and probability of which with frequency greater than or equal to 16 times were calculated. Data were processed with Pearson Chi-square test. Results: Over 2 years after injury, the MBI score of patients was (76±22) points, and the ADL of 83.08% (54/65) patients reached completely self-care or light ADL disorder level. The MBI items arranged according to the completing independent level of patients from high to low were urine control/stool control, walking, bed and chair transfer, going up and down stairs, going to the toilet, eating, grooming, dressing, and bathing. The independent level of patients completing self-care MBI items was lower than that of mobility items (χ(2)=62.298, P<0.001). Over 2 years after injury, the five most serious occupational activity disorders in COPM dimension were mainly concentrated in the self-care dimension, accounting for 55.38% (180/325), followed by 22.46% (73/325) of production activities and 22.15% (72/325) of recreational activities, and the centrally distributed item was the personal self-care item under self-care dimension, accounting for 42.46% (138/325). Over 2 years after injury, the five most serious occupational activity disorders with frequency greater than or equal to 16 times were dressing and undressing, bathing, perineal cleaning, wearing pressure clothes, caring for children, visiting relatives and friends, 31, 25, 16, 17, 18, and 22 times respectively, with a probability of 47.69%, 38.46%, 24.62%, 26.15%, 27.69%, and 33.85% respectively. Conclusions: Over 2 years after injury, most of the patients with extremely severe burns caused by the aluminum dust explosion were completely or basically self-care in their daily life. The disorder of self-care ADL was more serious than that of mobility, and the disorder of individual self-care activity was still the most serious occupational activity disorder of patients in this stage. Clinical trial registration: Chinese clinical trial registry, ChiCTR-OOC-16009188.

Effects of phyto-oestrogen quercetin on productive performance, hormones, reproductive organs and apoptotic genes in laying hens

Quercetin, a polyphenolic flavonoid with diverse biological activities including anti-inflammatory and antiviral, inhibits lipid peroxidation, prevents oxidative injury and cell death. The purpose of the research was to investigate the effect of quercetin on productive performance, reproductive organs, hormones and apoptotic genes in laying hens between 37 and 45 weeks of age, because of the structure and oestrogenic activities similar to 17β-oestradiol. The trial was conducted using 240 Hessian laying hens (37 weeks old), housed in wire cages with two hens in each cage. These hens were randomly allotted to four treatments with six replicates, 10 hens in each replicate and fed with diets containing quercetin as 0, 0.2, 0.4 and 0.6 g/kg feed for 8 weeks. The results showed that dietary quercetin significantly increased (p < .05) the laying rate and was higher in group supplemented with 0.4 g/kg, and feed-egg ratio was decreased (p < .05) by quercetin. Dietary quercetin has no effect (p > .05) on average egg weight and average daily feed intake. Compared with control, secretion of hormones, oestradiol (E₂ )_, progesterone (P4), follicle-stimulating hormone (FSH), luteinizing hormone (LH), insulin-like growth factors-1 (IGF-1) and growth hormone (GH), was found to be significantly higher (p < .05) in quercetin-supplemented groups. Also ovary index, uterus index and oviduct index were not significantly influenced (p > .05) by quercetin, whereas magnum index, isthmus index, magnum length, isthmus length and follicle numbers were significantly increased (p < .05) with quercetin supplementation. Additionally, expression of apoptotic genes was significantly (p < .05) up-regulated or down-regulated by quercetin. These results indicated that quercetin improved productive performance, and its mechanism may be due to the oestrogen-like activities of quercetin.

[Influence of the Arg-Gly-Asp-Ser sequence on the biological effects of bioactive glass on human dental pulp cells]

OBJECTIVE

Positive effects of bioactive glass (BG) on proliferation, mineralization, and differentiation of human dental pulp cells (hDPCs) was already verified in various former studies. The Arg-Gly-Asp-Ser sequence (RGDS) was confirmed of affecting cell adhesion. Before further investigation, the objective of this study is to investigate whether RGDS can affect the effects of BG on the adhesion, proliferation and mineralization of hDPCs.

METHODS

hDPCs were harvested from third molars of 18-25-year-old individuals after informed consent. Enzyme digestion technique was used. The 4th to 6th generation of hDPCs were used for all experiments. The cells of the experimental groups were cultured in Dulbecco minimum essential medium (DMEM) containing ionic dissolution products of BG and RGDS of several concentrations (12.5 mg/L, 25.0 mg/L, 50.0 mg/L, 100.0 mg/L, 200.0 mg/L). DMEM containing ionic dissolution products of BG without RGDS was used for cell culture as control group. Cell adhesion was tested 4 h after cell seeding by MTT assay. Cell proliferation was examined at 1, 3, 5, 7, and 9 d after cell seeding by MTT assay. Cell mineralization was investigated on days 14 and 28 by alizarin red staining. After being stained and dried, mineralized nodules were dissolved by cetylpyridinium chloride (CPC) for semi-quantitative test. Results were statistically analyzed by one way ANOVA, SPSS (version 19.0) and P<0.05 was considered to be significant.

RESULTS

Cell adhesion in BG group showed no difference from that in DMEM group. Compared with BG group, hDPCs in BG+RGDS groups suggested weaker cell adhesion.When the concentration of RGDS increased, the adhered cell number decreased. hDPCs cultured with BG and RGDS showed lower proliferation activity in the early stage, while no significant difference was observed after 3 d. BG group promoted the mineralization of hDPCs compared with positive control group, negative control group and RGDS group. No significant difference was observed between BG+RGDS group and BG group or between RGDS group and positive control group.

CONCLUSION

BG promotes proliferation and mineralization without affecting cell adhesion of hDPCs. Unbounded RGDS inhibits cell adhesion, but has no influence on the positive effects of BG on the proliferation and mineralization of hDPCs.

[Effects of bioactive glass and extracted dentin proteins on human dental pulp cells]

OBJECTIVE

To investigate the proliferation, odontogenic differentiation and mineralization of human dental pulp cells (HDPCs) on bioactive glass(BG) and extracted dentin proteins(EDP).

METHODS

Primary HDPCs were isolated from third molars by enzyme digestion and were cultured in Dulbecco's minimum essential medium (DMEM). Then the 4th generation of HDPCs was cultured with DMEM, which contained BG-EDP, BG, and EDP, respectively. Meanwhile HDPCs were cultured in DMEM as control group. Proliferation of HDPCs was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) colorimetric assay. Odontogenic differentiation was determined by alkaline phosphatase (ALP) activity assay and real-time PCR. Mineralization was investigated by Alizarin red staining and cetylpyridinium chloride (CPC) assay.

RESULTS

The proliferation of HDPCs was increased significantly in BG-EDP group on 3,7,and 9 d (optical density value: 1.36±0.06, 2.52±0.20, 2.72±0.29) compared with BG (optical density value: 1.20±0.26, 2.33±0.26, 2.50±0.30), EDP(optical density value: 1.13±0.15, 2.10±0.13, 2.38±0.22) and control group (optical density value: 0.84±0.17, 1.84±0.18, 1.95±0.19), P<0.05. After 7 days, ALP activity of BG-EDP group had no statistical difference compared with EDP group and control group; the expression of odontogenic differentiation genes (DSPP, DMP-1) showed no difference among all the groups(P>0.05). After 14 days, ALP activity of BG-EDP group (56.67±1.83) was significantly upregulated compared with EDP group (41.98±9.71) and control group (30.82±6.70), P<0.05, but had no statistical difference compared with BG group (56.29±6.20), P>0.05; DSPP gene expression was upregulated significantly in BG-EDP group (5.79±1.94) compared with the other groups (P<0.05); DMP-1 gene expression of BG-EDP group (3.87±1.87) increased but had no statistical difference compared with the other groups (P>0.05). The alizarin red staining showed more mineral nodules in BG-EDP group, the cetylpyridinium chloride semi-quantification presented higher calcification in BG-EDP group (0.27±0.01) compared with the other groups (P<0.05).

CONCLUSION

Compared with either BG or EDP, BG-EDP significantly promotes the proliferation, odontogenic differentiation and mineralization of HDPCs.

[Clinical efficacy and safety of vancomycin compared with linezolid for the treatment of neonatal gram-positive bacterial sepsis]

OBJECTIVE

To evaluate the clinical efficacy and safety of vancomycin and linezolid for the treatment of gram-positive neonatal bacterial sepsis.

METHOD

The data of neonates diagnosed as gram-positive bacterial sepsis in neonatology department of Suzhou Municipal Hospital from June 2009 to December 2015 were retrospectively collected. These neonates were divided into vancomycin group and linezolid group. Propensity score matching (PSM) on baseline variables was used to balance the two groups by identifying a comparable group of neonates who received vancomycin and linezolid therapy. Clinical and microbiologic success rates were compared by chi-square test, and changes of laboratory parameters before and after treatment at the end of treatment were then directly compared by rank-sum test between the matched groups. In vancomycin group, correlation between trough concentration of vancomycin and clinical efficacy were evaluated.

RESULT

Totally 108 and 209 cases were respectively selected in vancomycin and linezolid groups; 108 cases with well-matched baseline characteristics were included in matched linezolid group. The clinical success rates of vancomycin vs. linezolid therapy were 86.1%(93/108) and 88.9%(96/108)(P=0.681), and the microbiologic success rates were 91.7%(99/108) and 93.5%(101/108)(P=0.795). The average trough concentration of vancomycin was (12±8) mg/L. The rate of reaching the high trough concentration standard was only 33.3%(36/108). In 50 (46.3%) cases the dose was adjusted according to the initial concentration data. Compared to less than 10 mg/L, the clinical efficacy of trough concentration in 10-20 mg/L was much higher(93.9%(46/49) vs. 78.6%(33/42), P=0.031). Total bilirubin and platelet count had significant difference between the two-matched groups (34.1(14.9, 91.0)μmol/L vs. 53.0(27.0, 121.6)μmol/L, P=0.034; 301.0(198.8, 416.0)×10(9)/L vs. 195.5(94.0, 283.2)×10(9)/L, P=0.000). The incidence of linezolid related thrombocytopenia was 13.4%(28 cases).

CONCLUSION

The clinical effect of vancomycin and linezolid on gram-positive bacterial sepsis in neonates is comparable. The rate of trough concentration of vancomycin reaching the high trough concentration standard is low, and the clinical efficacy is related to trough concentration. Linezolid have an effect on bilirubin and platelet count, the risk of thrombocytopenia should be monitored closely during linezolid treatment.

[Spatial distribution characteristics analysis on multidrug-resistant tuberculosis cases in Zhejiang province, 2010-2012]

OBJECTIVE

To analyze the spatial distribution characteristics of multidrug-resistant (MDR) tuberculosis (TB) cases in Zhejiang province in 2010-2012.

METHODS

Data on MDR-TB cases in Zhejiang province were collected and linked to the digital map at the county and district levels. ArcGIS 10.0 software was used for spatial analysis.

RESULTS

RESULTS from the spatial autocorrelation analysis showed that spatial aggregation appeared in MDR-TB distribution during 2010-2012 while local Moran's I spatial autocorrelation analysis identified several "high incidence regions" (Wuxing, Deqing, Yuhang, Gongshu, Jianggan, Xiaoshan, Yuecheng, Shaoxing Shengzhou, Changshan, Kecheng), and "low incidence region" (Haishu). Through Getis-Ord General G spatial autocorrelation analysis, 18 "positive hotspots" (Wuxing, Nanxun, Deqing, Yuhang, Shangcheng, Xiacheng, Gongshu, Jianggan, Binjiang Xiaoshan Xihu, Haining, Yuecheng, Shaoxing, Zhuji, Shengzhou, Kecheng and Suichang) and 11 "negative hotspots" (Nanhu, Haiyan, Cixi, Dinghai, Zhenhai, Jiangbei, Jiangdong, Beilun, Yinzhou, Fenghua, and Yueqing) were identified.

CONCLUSIONS

Spatial analysis on MDR-TB incidence implied the spatial aggregation in Zhejiang province. Data showed that the hotspots with high population density and human movement were under progressive expansion.

Predicting precipitation on nonpoint source pollutant exports in the source area of the Liao River, China

The source area of the Liao River is an important grain growing area in China which experiences serious problems with agricultural nonpoint source pollution (NPS) which is impacting the regional economy and society. In order to address the water quality issues it is necessary to understand the spatial distribution of NPS in the Liao River source area. This issue has been investigated by coupling a wavelet artificial neural network (WA-ANN) precipitation model with a soil and water assessment tool (SWAT) model to assess the export of nonpoint source pollutants from the Liao River source area. The calibration and validation of these models are outlined. The WA-ANN models and the SWAT model were run to generate the spatial distribution of nonpoint source nutrient (nitrogen and phosphorus) exports in the source area of the Liao River. It was found that the SWAT model identified the sub-catchments which not only receive high rainfall but are also densely populated with high agricultural production from dry fields and paddy fields, which are large users of pesticides and chemical fertilizer, as the primary source areas for nutrient exports. It is also concluded that the coupled WA-ANN models and the SWAT model provide a tool which will inform the identification of NPS issues and will facilitate the identification of management practices to improve the water environments in the source area of the Liao River.

Biodegradation of nicotine by a newly isolated Agrobacterium sp. strain S33

AIMS

To isolate and characterize bacteria capable of degrading nicotine from the rhizospheric soil of a tobacco plant and to use them to degrade the nicotine in tobacco solid waste.

METHODS AND RESULTS

A bacterium, strain S33, was newly isolated from the rhizospheric soil of a tobacco plant, and identified as Agrobacterium sp. based on morphology, physiological tests, Biolog MicroLog3 4.20 system and 16S rRNA gene sequence. Using nicotine as the sole source of carbon and nitrogen in the medium, it grew optimally with 1.0 g l(-1) of nicotine at 30 degrees C and pH 7.0, and nicotine was completely degraded within 6 h. The resting cells prepared from the glucose-ammonium medium or LB medium could not degrade nicotine within 10 h, while those prepared from the nicotine medium could completely degrade 3 g l(-1) of nicotine in 1.5 h at a maximal rate of 1.23 g nicotine h(-1) g(-1) dry cell. Using the medium containing nicotine, glucose and ammonium simultaneously to cultivate strain S33, the resting cells could degrade 98.87% of nicotine in tobacco solid waste with the concentration as 30 mg nicotine g(-1) dry weight tobacco solid waste within 7 h at a maximal rate of 0.46 g nicotine h(-1) g(-1) dry cell.

CONCLUSIONS

This is the first report that Agrobacterium sp. has the ability to degrade nicotine. Agrobacterium sp. S33 could use nicotine as the sole source of carbon and nitrogen. The use of resting cells of the strain S33 prepared from the nicotine-glucose-ammonium medium was an effective method to degrade nicotine and detoxify tobacco solid waste.

SIGNIFICANCE AND IMPACT OF THE STUDY

Nicotine in tobacco wastes is both toxic and harmful to human health and the environment. This study showed that Agrobacterium sp. S33 may be suitable for the disposal of tobacco wastes and reducing the nicotine content in tobacco leaves.

Distribution of Baseline Sensitivities to Natural Product Physcion Among Isolates of Sphaerotheca fuliginea and Pseudoperonospora cubensis

The ethanol extract from rhubarb was commercialized in China (Veguard, Physcion, 5 g/liter AS) for control of cucumber powdery mildew (Sphaerotheca fuliginea) and cucumber downy mildew (Pseudoperonospora cubensis). To provide the basic data for the risk assessment of resistance to this product, physcion was selected to represent the active ingredients to establish baseline sensitivity of powdery mildew and downy mildew populations. For powdery mildew, 262 isolates of S. fuliginea from nine regions and, for downy mildew populations, 116 isolates of P. cubensis from six regions were collected in China during 2004 and 2005 and tested for sensitivity. In addition, the sensitivity of a powdery mildew isolate was monitored for 15 asexual generations under selection pressure with physcion. The results showed that there was no significant difference among regions in the frequency distribution of baseline sensitivity to this ingredient for either cucumber powdery mildew isolates or cucumber downy mildew isolates. Baseline sensitivity was distributed as a normal unimodal curve with a mean median (50%) effective concentration (EC₅₀) of 0.304 μg/ml for powdery mildew population and mean EC₅₀ of 0.501 μg/ml for downy mildew population. The variation of sensitivity to physcion was low because the range factor (maximum EC₅₀/minimum EC₅₀ of isolates within population) varied from 1.63 to 3.42 among powdery mildew populations and from 1.70 to 2.38 among downy mildew populations. The powdery mildew isolate XZ4 did not decrease sensitivity under the selection pressure of physcion at the dose of EC₇₀ for 15 generations.

Hyperleptinaemia and hypoadiponectinaemia are associated with gallstone disease

BACKGROUND

Gallstone disease has been regarded as an obesity-related disease. Therefore, we hypothesized that leptin and adiponectin, mainly produced by adipose tissue, may play roles in gallstone disease.

PATIENTS AND METHODS

The RIA method was used to analyze serum leptin and adiponectin levels of 90 gallstone patients and 91 healthy subjects.

RESULTS

Our results showed that BMI, fasting glucose, serum AST and ALT, and leptin were significantly increased in the gallstone patients as compared with the healthy subjects (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.013, respectively). Intriguingly, serum adiponectin was the only variable to be significantly decreased in the gallstone patients (P = 0.002). Furthermore, serum AST, leptin, and adiponectin were significantly associated with gallstone disease (P < 0.001, P = 0.021, and P = 0.006, respectively). Overweight (BMI >or= 25 kg m(-2)), but not normal-weight, gallstone patients had an increased serum leptin and a decreased serum adiponectin level as compared with matched healthy subjects (P < 0.001 and P = 0.024, respectively). In addition, serum leptin was positively correlated with BMI and serum cholesterol, while serum adiponectin was inversely correlated with serum triglyceride in the gallstone patients.

CONCLUSIONS

Our study indicated that hyperleptinaemia and hypoadiponectinaemia might be involved in the occurrence of gallstone disease. However, the causal relationship of hyperleptinaemia and hypoadiponectinaemia with gallstone disease might require further investigation.

Biodegradation and detoxification of nicotine in tobacco solid waste by a Pseudomonas sp

A Pseudomonas sp. grew with nicotine optimally 3 g l(-1) and at 30 degrees C and pH 7. Nicotine was fully degraded within 10 h. The resting cells degraded nicotine in tobacco solid waste completely within 6 h in 0.02 m sodium phosphate buffer (pH 7) at maximally 56 mg nicotine h(-1) g dry cell(-1).

Growth inhibition and apoptosis induction of Sulindac on Human gastric cancer cells

AIM: To evaluate the effects of sulindac in inducing growth inhibition and apoptosis of human gastric cancer cells in comparison with human hepatocellular carcinoma (HCC) cells.

METHODS: The human gastric cancer cell lines MKN45 and MKN28 and human hepatocellular carcinoma cell lines HepG₂ and SMMC7721 were used for the study. Anti-proliferative effect was measured by MTT assay, and apoptosis was determined by Hoechst-33258 staining, electronography and DNA fragmentation. The protein of cyclooxygenase-2 (COX-2) and Bcl-2 were detected by Western dot blotting.

RESULTS: Sulindac could initiate growth inhibition and apoptosis of MKN45, MKN28, HepG₂ and SMMC7721 cells in a dose-and time-dependent manner. Growth inhibitory activity and apoptosis were more sensitive in HepG₂ cells than in SMMC7721 cells, MKN45 and MKN28 cells. After 24 h incubation with sulindac at 2 mmol•L¯¹ and 4 mmol•L¯¹, the level of COX-2 and Bcl-2 protein were lowered in MKN45, SMMC7721 and HepG₂ cells but not in MKN28 cells.

CONCLUSION: Sulindac could inhibit the growth of gastric cancer cells and HCC cells effectively in vitro by apoptosis induction, which was associated with regression of COX- 2 and Bcl-2 expression. The growth inhibition and apoptosis of HCC cells were greater than that of human gastric cancer cells. The different effects of apoptosis in gastric cancer cells may be related to the differentiation of the cells.

Growth factor ultrafiltration in experimental diabetic nephropathy contributes to interstitial fibrosis

Glomerular proteinuria is a risk factor for progression of chronic renal failure and contributes to renal interstitial fibrosis. In experimental diabetic glomerular sclerosis, there is translocation of high-molecular-weight growth factors, namely, hepatocyte growth factor (HGF) and transforming growth factor (TGF)-beta, from plasma into tubular fluid, both of which act on tubular cells through apical membrane receptors. In the present studies, the hypothesis is examined that ultrafiltered HGF and TGF-beta induce increased expression of extracellular matrix (ECM) proteins directly in tubular cells, or induce increased expression of cytokines that may act on interstitial myofibroblasts. Incubation of cultured tubular cells with recombinant human (rh) TGF-beta modestly raises expression of collagen type III, but rhHGF dose dependently blocks expression of this ECM protein. Both growth factors raise fibronectin expression up to fourfold and increase expression of platelet-derived growth factor (PDGF)-BB up to sixfold, but not of fibroblast growth factor-2. Pooled, diluted glomerular ultrafiltrate that had been collected by nephron micropuncture from rats with diabetic nephropathy (24-30 wk) also raises expression of fibronectin as well as PDGF-BB in proximal tubular cells. In the presence of neutralizing antibodies that block actions of HGF and TGF-beta, diabetic rat glomerular ultrafiltrate fails to increase tubular cell PDGF-BB expression. In NRK-49F renal interstitial myofibroblasts, rhPDGF-BB, in turn, raises the expression of collagen type III but not type I or fibronectin. The findings provide evidence for ultrafiltered HGF and TGF-beta to contribute to interstitial accumulation of ECM proteins by direct effects on tubular cells as well as indirect mechanisms, via PDGF-BB and its action on myofibroblasts. These events may be important mechanisms of proteinuria-induced renal interstitial fibrosis and accelerated progression of chronic renal failure in diabetic nephropathy and perhaps other proteinuric glomerular diseases.

Role of glomerular ultrafiltration of growth factors in progressive interstitial fibrosis in diabetic nephropathy

BACKGROUND

The present in vivo and in vivo experiments were performed to test the hypothesis that in rats with glomerular proteinuria, the bioactive growth factors transforming growth factor-beta (TGF-beta) and hepatocyte growth factor (HGF) are ultrafiltered into tubular fluid, can interact with respective receptors in apical tubular cell membranes, increase the expression and basolateral secretion of C-C-chemokines, which interact with cells in the renal interstitium and indirectly cause myofibroblasts to increase the expression of extracellular matrix proteins.

METHODS

HGF and TGF-beta were measured by Western blot and bioassay in glomerular ultrafiltrate that was collected by nephron micropuncture from rats with diabetic nephropathy and control rats. Proximal tubular and collecting duct cells were incubated with diluted proximal tubular fluid or recombinant human HGF (rhHGF) or rhTGF-beta and expression of C-C-chemokines was measured by RT-PCR and ELISA. Interactions of tubular cell chemokines with macrophages and indirectly with myofibroblasts were also examined using cell culture models.

RESULTS

In rats with glomerular proteinuria due to diabetic nephropathy mature, bioactive HGF as well as active and latent TGF-beta were detected in early proximal tubular fluid. Specific HGF- and TGF-beta type II receptors were expressed in apical tubular membranes more in diabetic compared to control rats. Incubation of cultured mouse proximal tubular cells (mPTC) or medullary collecting duct cells (mIMCD-3) with diabetic rat proximal tubular fluid increased MCP-1 and RANTES mRNA levels as well as secreted peptide up to threefold. In contrast, high glucose (450 mg/dL), bovine serum albumin (BSA) or rat albumin (each at 100 micrograms/mL) or 10 nmol/L insulin-like growth factor-I (IGF-I; which was also present in glomerular ultrafiltrate in rats with diabetic nephropathy) did not affect expression of these chemokines. Recombinant human TGF-beta as well as rhHGF each increased MCP-1 and RANTES mRNA as well as peptide levels several-fold. In cultured macrophages MCP-1 raised the secretion of TGF-beta, which in turn increased the expression of collagen type I and III as well as fibronectin in renal interstitial myofibroblasts about 2.5 to 4-fold.

CONCLUSIONS

Proteinuria-induced progressive renal interstitial fibrosis may be caused by glomerular ultrafiltration of high molecular weight bioactive growth factors, HGF and TGF-beta, which "activate" tubular cells through apical membranes. These apical signals are translated into basolateral events that are recognized by cells in the interstitium, such as the basolateral secretion of the C-C-chemokines MCP-1 and RANTES, which may (via macrophages) stimulate interstitial myofibroblasts, and thus lead to accumulation of extracellular matrix proteins and progressive interstitial fibrosis.

Glomerular ultrafiltration and apical tubular action of IGF-I, TGF-beta, and HGF in nephrotic syndrome

In nephrotic glomerulopathies, there is ultrafiltration of high molecular weight forms of insulin-like growth factor-I (IGF-I), hepatocyte growth factor (HGF), and transforming growth factor-beta (TGF-beta), which are bioactive in tubular fluid and act through apical tubular receptors. Experimental evidence indicates that ultrafiltered IGF-I, HGF, and TGF-beta may contribute to increased tubular phosphate and sodium absorption, synthesis of extracellular matrix proteins, and secretion of chemokines such as monocyte chemoattractant protein-1 (MCP-1). Through these mechanisms, glomerular proteinuria may contribute to tubulointerstitial pathobiology in nephrotic syndrome.

Propofol-induced alterations in myocardial beta-adrenoceptor binding and responsiveness

Propofol (iv) depresses cardiovascular function in both humans and animals. However, the mechanism underlying this action has not been well described. The present study was designed to test the hypothesis that this effect of propofol results in part from an antagonism of adrenergic control of the heart. Experiments examined effects of propofol on: 1) [3H]CGP12177 (a beta-adrenoceptor antagonist) binding in rat myocardial membranes; and 2) the inotropic and chronotropic actions of isoproterenol in rat left atrial muscle and right atria, respectively. Propofol (25-200 microM) increased the apparent dissociation constant for [3H]CGP12177 without affecting binding site density. Similarly, 200 microM propofol increased the 50% effective concentration values for the dose-dependent positive chronotropic and inotropic actions of isoproterenol in right and left atria, and depressed the maximum increase in spontaneous rate elicited by this beta-adrenoceptor agonist. Other experiments demonstrated that propofol does not alter muscarinic receptor binding as monitored using [3H]quinuclidi-nylbenzilate. In conclusion, these results indicate that propofol can decrease cardiac beta-adrenoceptor responsiveness; however, the concentrations of propofol required suggest that this action contributes to the cardiovascular depression produced by this anesthetic only during large-dose bolus injection.

IMPLICATIONS

Experiments in membranes and cardiac preparations isolated from rat heart demonstrate that relatively high concentrations of propofol (25-200 microM) are required to antagonize beta-adrenoceptor binding and tissue responsiveness.

Glomerular ultrafiltration of IGF-I may contribute to increased renal sodium retention in diabetic nephropathy

Insulin-like growth factor-I (IGF-I) is found in plasma at relatively high levels (approximately 40 nmol/L) but <1% is present in the free form and >99% is bound to specific binding proteins to form high-molecular-weight complexes of approximately 50 and approximately 150 kd. We hypothesized that in rats with diabetic nephropathy but not in normal animals, IGF-I-containing binding protein complexes undergo glomerular ultrafiltration, allowing the peptide to interact with IGF-I receptors in apical tubular membranes. By this route, ultrafiltered IGF-I may increase tubular epithelial cell sodium absorption in overt diabetic nephropathy. In serum samples from diabetic rats, IGF-I levels (227 +/- 34 ng/mL) were reduced as compared with control levels (319 +/- 33 ng/mL, P = .05), and IGF-binding protein-2 (IGFBP-2) is increased about 2-fold. In diabetic rats, IGF-I undergoes glomerular ultrafiltration and is present in proximal tubular fluid that was collected by nephron micropuncture at 2.54 +/- 0.54 nmol/L but is below the detection limit in tubular fluid from normal rats. IGFBP-1, IGFBP-2, IGFBP-3, and IGFBP-4 are all present in diabetic rat glomerular ultrafiltrate, but IGFBP-2 levels are greater than those of each of the other three IGFBPs. Neither recombinant human IGF-I (1 nmol/L) nor diabetic rat glomerular ultrafiltrate affect sodium transport in cultured mouse proximal tubular cells. In contrast, rhIGF-I and diabetic rat glomerular ultrafiltrate increase the apical-to-basolateral transport of 22Na+ in distal tubule-like A6 cells through mechanisms involving apical IGF-I receptors. In normal rats, luminal infusion with rhIGF-I or with diabetic rat glomerular ultrafiltrate into late proximal tubules increases distal tubular Na+ absorption. These findings indicate that diabetic glomerular sclerosis causes glomerular ultrafiltration of IGF-I, and they suggest that tubular fluid IGF-I may contribute to sodium (and fluid) retention that is commonly observed in patients with severe diabetic nephropathy.

Pathophysiologic glomerulotubular growth factor link

Circumstantial evidence from clinical and pathologic correlations in patients with glomerular diseases and proteinuria suggest that glomerular protein ultrafiltration contributes to tubulointerstitial injury. A series of studies was performed to examine the hypothesis that in rats with adriamycin-induced nephropathy or with diabetic nephropathy (but not in normal rats) high molecular wt. growth factors are ultrafiltered into tubular fluid and act on tubular cells through apical membrane receptors. Analysis of proximal tubular fluid that was collected by nephron micropuncture indicates ultrafiltration of IGF-I, TGF-beta and HGF. Respective receptors are also expressed in apical membranes in some parts of the nephron as examined by immunohistochemistry. In vitro cell culture experiments using proximal tubular fluid obtained from rats with experimental glomerular diseases indicate that ultrafiltered IGF-I may contribute to increased distal tubular Na-absorption. Indirect evidence also suggests that this growth factor may increase the secretion of collagen types I and IV in proximal tubular cells. TGF-beta and HGF cause increased expression and basolateral secretion of MCP-1 in proximal tubular and collecting duct cells. There may be other biologic effects on tubules that are caused by apical exposure to ultrafiltered growth factors. These studies suggest that the glomerular ultrafiltration of bioactive proteins causes or contributes to tubulo-interstitial pathology in glomerular proteinuria.

Effect of early application of biphasic positive airway pressure on the outcome of extubation in ventilator weaning

Extubation failure is significantly associated with increased morbidity and mortality in mechanically ventilated patients. In respiratory distress after extubation, non-invasive positive pressure ventilation (NIPPV) has been suggested to avoid the complications of invasive mechanical ventilation. The purpose of this study was to evaluate the effect of early application of NIPPV on extubation outcome. We conducted a prospective study in 93 extubated patients with a mean age of 72.7 +/- 14.7 years (range, 24-93). Elective extubation was performed in 56 patients and unplanned extubation occurred in 37 patients. After extubation, patients randomly received either biphasic positive airway pressure (BIPAP) therapy (n = 47) or unassisted oxygen therapy (n = 46). Non-invasive positive pressure ventilation was delivered via face mask in BIPAP group. Of the 93 extubated patients, 73 (78.5%) were successfully extubated, and 20 (21.5%) had to be re-intubated. There were no significant differences in age, sex, pre-extubation blood gas data between re-intubated patients and those who were not re-intubated. While seven of the 46 patients in the unassisted oxygen therapy group required re-intubation, 13 of the 47 BIPAP-treated patients also required re-intubation. This difference was not statistically significant. The postextubation respiratory management, BIPAP or unassisted oxygen therapy, did not correlate with the extubation outcome, but the elective extubation had significantly better outcome than unplanned extubation. Patients with excessive bronchial secretions and intolerance to the equipment are poor candidates for NIPPV. We conclude that early application of BIPAP support did not predict a favourable extubation outcome. Our experience did not support the indiscriminate use of NIPPV to facilitate ventilator weaning.

Effects of gender on the sensitivity of rat cardiac muscle to extracellular Ca2+

Experiments were designed to determine if the inotropic response to increasing buffer calcium concentration differs in male and female cardiac muscle. Left atrial and papillary muscles were isolated from hearts of 3-4-month old male and female rats, bathed in Krebs-Henseleit solution (30 degrees C), and stimulated at 1.5 Hz. Isometric developed tension was monitored continuously as extracellular Ca2+ was increased in a cumulative fashion. When compared to male atrial muscle, female atrial preparations were more sensitive to the resulting positive inotropic action; EC50 values were 2.89 +/- 0.22 and 1.86 +/- 0.21 mM in male and female atria, respectively. Two-way analysis of variance (ANOVA) also indicated that there was a significant gender-associated difference in the Ca2+ dose-response curves in atrial muscle. In contrast, papillary muscle did not show a significant gender-related difference in EC50 values (0.88 +/- 0.07 and 0.74 +/- 0.06 mM in males and females); however, the Ca2+ dose-response curves obtained from male and female preparations were found to be significantly different when compared by ANOVA.

Traumatic brain injury does not alter cerebral artery contractility

Previous studies have shown that traumatic brain injury (TBI) significantly reduces cerebral blood flow determined in vivo and reduces vascular reactivity in the pial circulation measured with cranial window preparations. We have now tested the hypothesis that TBI induces these changes by impairing intrinsic contractile activity of cerebral arteries. Anesthetized rats underwent moderate (2.2 atm) and severe (3.0 atm) midline fluid percussion TBI or sham injury following which posterior cerebral or middle cerebral arteries were isolated and isometric force generation was measured. Moderate (n = 5) and severe (n = 3) trauma had no effect on the magnitude of serotonin- or K+-induced force generation or sensitivity to serotonin in arteries isolated within 10 min of TBI. Functional disruption of the endothelium of posterior cerebral arteries isolated 10 min after moderate trauma or sham injury caused a reduction in the active tension response to serotonin that was similar in both groups. Blockade of cyclooxygenase with 5 microM indomethacin had no effect on serotonin-induced force generated by vessels with moderate trauma or in sham-treated rats. Acetylcholine induced an endothelium-dependent relaxation of posterior and middle cerebral arteries; the magnitude of the response was unaffected by moderate TBI. To determine whether prolonged in situ exposure of vessels to the traumatized cerebral milieu could reveal an alteration in intrinsic contractility, posterior cerebral arteries were isolated 30 min after TBI; again, no differences in the tension or relaxation responses were observed. It is concluded that midline fluid percussion TBI did not affect contraction or relaxation of proximal middle or posterior cerebral arteries in rats.

Alpha 1D-adrenoceptors play little role in the positive inotropic action of phenylephrine

This study was designed to determine if the positive inotropic action of alpha 1-adrenergic stimulation in rat heart is mediated via alpha 1D-adrenoceptors. Isolated left atrial and papillary muscle were suspended in oxygenated Krebs-Henseleit buffer (37 degrees C) containing 1 microM nadolol and paced at 3.0 Hz. Isometric tension was continuously monitored. Cumulative concentration-response curves for phenylephrine were obtained in the presence and absence of BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspirol[4.5] decane-7,9-dione), a selective competitive alpha 1D-adrenoceptor antagonist. BMY 7378 at concentrations up to 30 nM did not significantly affect the positive inotropic response to phenylephrine. In contrast, as reported by other investigators, alpha 1D-adrenoceptor-selective concentrations of this antagonist (3 and 10 nM) did elicit a concentration-dependent right-ward shift in the vasoconstrictor response to phenylephrine in rat abdominal aorta. These data suggest that alpha 1D-adrenoceptors do not play a major role in the positive inotropic action of alpha-adrenoceptor stimulation in rat cardiac muscle.

Effects of aging on Na(+)-pump current in rat ventricular myocytes

This study was designed to determine if aging affects ouabain-sensitive Na(+)-pump current (Ip), an electrophysiological measure of Na,K-ATPase activity, in rat heart. Ventricular myocytes were enzymatically isolated from hearts of young adult (4-6 months of age) and aged (28-36 months of age) male Long-Evans rats. Ip was monitored using conventional whole-cell patch-clamp techniques under both maximally stimulating (85 mM intracellular Na+ with 10.8 mM extracellular K+) and 'physiological' (10 mM intracellular Na+ with 5.4 mM extracellular K+) conditions. Values were expressed relative to membrane capacitance to account for the larger cell size of the aged myocytes. Results indicated that maximal Ip is smaller (e.g. approximately 23% at the holding potential of -40 mV) in myocytes isolated from aged as compared to young adult rats. However, neither the voltage-dependence of maximal Ip nor the pump current monitored under 'physiological' conditions were affected by age in general, these data support results of previous biochemical and ion flux studies which demonstrated that aging is associated with a decline in the Na(+)-pump capacity of the myocardium.

[Study on hsp 70 gene level in cultured smooth muscle cells and aorta from SHR and WKY rats]

Using nucleic hybridization, we investigated hsp 70 gene level on: 1. aorta on spontaneous hypertension rats (SHR); 2. cultured SHR and WKY smooth muscle cells (SMCs) induced by heat shock; 3. cultured SHR and WKY SMCs in 6 weeks and 3 months. The results indicated that hsp 70 mRNA increased in aorta of SHR (6 weeks), in cultured SHR SMCs as compared with WKY SMCs induced by heat shock (42 degrees C, 15 minutes), and in cultured SHR SMCs (6 weeks) as compared with WKY SMCs (6 weeks). Meanwhile, hsp 70 mRNA of cultured SHR SMCs in 6 weeks was higher than that in 3 months. We postulated that overexpression of hsp 70 of cultured SMCs and aorta of SHR in 6 weeks might be related with cellular proliferation during the development of hypertension and that the cultured SHR SMCs might be sensitive to heat shock.

Antigen expression associated with lymph node metastasis in gastric adenocarcinomas

A total of 100 gastric adenocarcinomas, comprising 50 cases with lymph node metastasis and 50 cases without lymph node metastasis, were examined for immunohistochemical reactivity with the monoclonal antibody to urokinase-type plasminogen activator (u-PA), Lex related 4C9 antigen, Jun, or to nucleobindin (Nuc). In tumors with lymph node metastasis, 41 (82%) were positive for u-PA and 28 (56%) were positive for Nuc. In tumors without lymph node metastasis, 26 (52%) were positive for u-PA and five (10%) were positive for Nuc. The percentage of cases positive for u-PA or Nuc was significantly higher in tumors with lymph node metastasis than that in tumors without lymph node metastasis (P < 0.01). The expression of u-PA was found to be significantly correlated with that of Nuc (P < 0.001), mode of infiltrative growth (P < 0.05), depth of invasion (P < 0.01), and grade of lymphatic invasion (P < 0.01). However, the expression of Nuc was found to be significantly correlated with the expression of Jun (P < 0.05), depth of invasion (P < 0.01), and grade of lymphatic invasion (P < 0.001). These results suggest that immunohistochemical examination for the expression of u-PA and Nuc in tumor cells may help evaluate the potential of adenocarcinomas of the stomach for lymph node metastasis.

[Comparison on the kidney nourishing and yang strengthening functions of three different species of herba Cistanches]

Oral administration of water extraction of three kinds of herba cistanches can increase the weight of young mice, prolong the duration of swimming and promote anoxia tolerance in mice. These water decoctions can also increase the body weight, the activities of SOD in serum and the lifespan of "Yang insufficient" model mice induced by administration of hydrocortisone acetate.

Vasoactive intestinal peptide: electrophysiologic activity in the newborn heart

We performed intracardiac electrophysiologic studies of the effects of vasoactive intestinal peptide (VIP, 0.125 micrograms/kg/min) on sinus and atrioventricular (AV) nodal function, intracardiac conduction, and myocardial refractoriness in two groups of neonatal dogs (aged 6-16 d). Group I consisted of eight neonates in whom VIP was administered after bilateral vagotomy and beta-blockade with propranolol. Group II consisted of five neonates studied after vagotomy and propranolol, plus total chemical sympathectomy (6-hydroxydopamine). In both groups, VIP resulted in a significant shortening of sinus cycle length. AV nodal conduction time, measured as the AH interval (the time from the onset of the atrial electrogram to the onset of the His bundle electrogram in the His electrode catheter) during atrial pacing, also shortened after VIP. His-Purkinje conduction time and atrial effective refractory periods were unchanged by VIP. In other experiments, the direct chronotropic effect of VIP was evaluated in five isolated neonatal canine hearts using a modified Langendorff technique. In these hearts, the spontaneous cycle length decreased from 403 +/- 88 to 293 +/- 69 ms, or -28 +/- 4% (mean +/- SD), after exposure to 0.1-0.5 nmol of VIP (p < 0.001). In nine other newborns (aged 4-16 days), the effect of selective alpha 1- and alpha 2-adrenergic receptor blockade on the positive chronotropic effect of VIP was evaluated. The effect of VIP on sinus cycle length was not altered by the alpha 1-adrenergic receptor blocker prazosin or by the alpha 2-adrenergic receptor blocker yohimbine.(ABSTRACT TRUNCATED AT 250 WORDS)

Postnatal maturation of the response of the canine sinus node to critically timed, brief vagal stimulation

We have previously demonstrated that vagal phase-response curves (PRC), which characterize the effects of critically timed, brief vagal stimuli on sinus node automaticity, exhibit a fundamentally different shape in the canine newborn than in the adult. In this study we analyzed the changes in sinus cycle length in response to critically timed, brief vagal stimuli, delivered to the decentralized cervical right and left vagosympathetic trunks, in two older age groups: 14 1-mo-old puppies (ages 21-36 d), and eight 2-mo-old puppies (ages 56-62 d). Vagal PRC were constructed by plotting the magnitude (percent change) of the vagal chronotropic response as a function of the phase of the cardiac cycle at which the vagus nerve was stimulated. At 1 mo of age adult-type PRC were observed, but in only six of the puppies (43%) and only in response to right vagal stimulation. By 2 mo of age adult-type PRC were observed in seven of eight puppies (88%) in response to right vagal stimulation and in three of eight (38%) in response to left vagal stimulation. Thus, clear developmental changes in the phase dependence of the vagal chronotropic response can be tracked over the first 2 mo of life in the dog.

A role for the metal binding domain in determining the DNA sequence selectivity of Fe-bleomycin

Previous studies of Fe-bleomycin-mediated DNA cleavage have established that the bithiazole moiety + C-terminal substituent of bleomycin are required for DNA binding, while the metal binding domain is responsible for O2 activation. Although recent studies have indicated that the metal binding domain also participates in DNA unwinding, and in determining the sequence and strand selectivity of DNA cleavage, no study has defined the structural domain that bears primary responsibility for the observed pattern of bleomycin-mediated DNA degradation. Presently, by the use of four synthetic analogs of bleomycin demethyl A2 having the functional domains connected by rigid spacers of varying lengths, the source of DNA cleavage specificity has been determined. When the four analogs cleaved 242- and 127-base pair 5'-32P-end-labeled DNA restriction fragments containing isolated Fe-bleomycin cleavage sites, all four produced cleavage at the same preferred sites. Because the (oligo)glycine spacers altered the distance between the domains by as much as 14 A, the identical cleavage patterns argue that the primary determinant of sequence specificity for these analogs is the metal binding domain.