Evidence for Chiral Wobbler in Nuclei

Three ΔI=1 bands with the πg_{9/2}⊗νg_{9/2} configuration have been identified in _{35}^{74}Br_{39}. Angular distribution, linear polarization, and lifetime measurements were performed to determine the multipolarity, type, mixing ratio, and absolute transition probability of the transitions. By comparing these experimental observations with the corresponding fingerprints and the quantum particle rotor model calculations, the second and third lowest bands are, respectively, suggested as the chiral partner and one-phonon wobbling excitation built on the yrast band. The evidence indicates the first chiral wobbler in nuclei.

[Management of liver transplantation perioperative period in acute-on-chronic liver failure]

Acute-on-chronic liver failure (ACLF) is a potentially reversible entity that occurs in patients with chronic liver disease accompanied with or without cirrhosis and is characterized by extrahepatic organ failure and high short-term mortality. Currently, the most effective treatment method for patients with ACLF is liver transplantation; therefore, admission timing and contraindications must be emphasized. The function of vital organs such as the heart, brain, lungs, and kidneys should be actively supported and protected during the liver transplantation perioperative period in patients with ACLF. Focusing on the anesthesia management level during anesthesia selection, intraoperative monitoring, three-stage management, prevention and treatment of post-perfusion syndrome, monitoring and management of coagulation function, volume monitoring and management, and body temperature monitoring management for liver transplantation should strengthen anesthesia management. Additionally, standard postoperative intensive care treatment should be recommended, and grafts and other vital organ functions should be monitored throughout the perioperative period to promote early postoperative recovery in patients with ACLF.

Next-generation gene panel testing in adolescents and adults in a medical neuropsychiatric genetics clinic

Intellectual disability (ID) encompasses a clinically and genetically heterogeneous group of neurodevelopmental disorders that may present with psychiatric illness in up to 40% of cases. Despite the evidence for clinical utility of genetic panels in pediatrics, there are no published studies in adolescents/adults with ID or autism spectrum disorder (ASD). This study was approved by our institutional research ethics board. We retrospectively reviewed the medical charts of all patients evaluated between January 2017 and December 2019 in our adult neuropsychiatric genetics clinic at the McGill University Health Centre (MUHC), who had undergone a comprehensive ID/ASD gene panel. Thirty-four patients aged > 16 years, affected by ID/ASD and/or other neuropsychiatric/behavioral disorders, were identified. Pathogenic or likely pathogenic variants were identified in one-third of our cohort (32%): 8 single-nucleotide variants in 8 genes (CASK, SHANK3, IQSEC2, CHD2, ZBTB20, TREX1, SON, and TUBB2A) and 3 copy number variants (17p13.3, 16p13.12p13.11, and 9p24.3p24.1). The presence of psychiatric/behavioral disorders, regardless of the co-occurrence of ID, and, at a borderline level, the presence of ID alone were associated with positive genetic findings (p = 0.024 and p = 0.054, respectively). Moreover, seizures were associated with positive genetic results (p = 0.024). One-third of individuals presenting with psychiatric illness who met our red flags for Mendelian diseases have pathogenic or likely pathogenic variants which can be identified using a comprehensive ID/ASD gene panel (~ 2500 genes) performed on an exome backbone.

Effects of miR-18a on proliferation and apoptosis of gastric cancer cells by regulating RUNX1

OBJECTIVE

The aim of this study was to explore the effects of micro ribonucleic acid (miR)-18a on the proliferation and apoptosis of gastric cancer (GC) cells, and to elucidate the possible underlying mechanism.

PATIENTS AND METHODS

In this study, the expression of miR-18a in GC tissues and para-cancer tissues was verified by in situ hybridization (ISH) of GC tissue microarray (TMA). Meanwhile, the effect of miR-18a expression on the prognosis of GC patients was evaluated. GC AGS cell line was selected and transfected with miR-18a mimic and mimic control (NC) to up-regulate miR-18a expression in vitro. Thereafter, changes in cell proliferation, apoptosis and migration after transfection were detected by biological functional assays. Luciferase reporter gene assay was carried out to verify the target gene Runt-related transcription factor 1 (RUNX1) modulated by miR-18a. Finally, the Spearman's grade correlation coefficient was calculated to explore the correlation between the expressions of miR-18a and RUNX1.

RESULTS

ISH results of TMA showed that overexpression of miR-18a in GC tissues was significantly associated with low survival rate of patients (p<0.001). High expression of miR-18a remarkably enhanced the proliferation, migration and invasion of GC cells (p<0.05). Besides, it has been predicted in biology that RUNX1 is one of the target genes of miR-18a. Luciferase reporter gene assay showed that Luciferase activity in cells transfected with wild-type (WT) RUNX1 3' untranslated region (3'UTR) was significantly reduced (p<0.05). Moreover, the protein expression of RUNX1 decreased remarkably in GC cells with over-expression of miR-18a (p<0.05). All these findings indicated that the expression of miR-18a was negatively correlated with RUNX1 in GC cells (p<0.001, r=0.86).

CONCLUSIONS

MiR-18a exerts a high predictive value for the prognosis of GC patients by directly targeting the transcription factor RUNX1. All our findings may provide therapeutic candidates for GC identification.

Annealing studies combined with low temperature emission Mössbauer spectroscopy of short-lived parent isotopes: Determination of local Debye-Waller factors

An extension of the online implantation chamber used for emission Mössbauer Spectroscopy (eMS) at ISOLDE/CERN that allows for quick removal of samples for offline low temperature studies is briefly described. We demonstrate how online eMS data obtained during implantation at temperatures between 300 K and 650 K of short-lived parent isotopes combined with rapid cooling and offline eMS measurements during the decay of the parent isotope can give detailed information on the binding properties of the Mössbauer probe in the lattice. This approach has been applied to study the properties of Sn impurities in ZnO following implantation of ¹¹⁹In (T_½ = 2.4 min). Sn in the 4+ and 2+ charge states is observed. Above T > 600 K, Sn²⁺ is observed and is ascribed to Sn on regular Zn sites, while Sn²⁺ detected at T < 600 K is due to Sn in local amorphous regions. A new annealing stage is reported at T ≈ 550 K, characterized by changes in the Sn⁴⁺ emission profile, and is attributed to the annihilation of close Frenkel pairs.

Effects of propofol on proliferation and apoptosis of cardia cancer cells via MAPK/ERK signaling pathway

OBJECTIVE

To explore the influences of propofol on the proliferation and apoptosis of cardia cancer cells via mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway.

PATIENTS AND METHODS

A total of 65 surgical resection specimens of cardia cancer were selected as research objects and divided into control group and with low (12.5 μmol/L), medium (25 μmol/L), and high (50 μmol/L) propofol concentration groups. The apoptosis of cancer cells, ERK1/2 phosphorylation level, expressions of Caspase-3, B-cell lymphoma-2 (Bcl-2), and Bcl-2 associated X protein (Bax) in each group were detected.

RESULTS

Propofol in different concentrations could all effectively inhibit the proliferation of cardia cancer cells in a dose-dependent manner. Different concentrations of propofol promoted the apoptosis of cardia cancer cells, and the apoptosis rate constantly increased with the rising concentration of propofol (p<0.05). Propofol could repress the expression of Bcl-2 and up-regulate the expression levels of Caspase-3, Bax, and phosphorylated ERK1/2.

CONCLUSIONS

Propofol can inhibit the proliferation and induce the apoptosis of cardia cancer cells, and the action mechanism may be correlated with the inhibition on the MAPK/ERK signaling pathway.

Quantitative determination of circulating L-cartinine and its derivates contributes to Heart failure diagnosis, etiology discrimination and clinical prognosis prediction

Background

Despite the latest progress in heart failure therapy, early diagnosis and clinical prognosis prediction are still critical issues nowadays. It has been proved that carnitines play an essential role in fatty acid metabolism. However, it is unclear about the changes and clinical effects of circulating carnitines in heart failure.

Objectives

This study was designed to clarify the alteration of serum carnitine and its derivates in heart failure patients, and to verify the impact of carnitines on heart failure etiology discrimination and mortality prediction.

Methods

A total of 161 heart failure patients (Dilated cardiomyopathy: DCM, n=98; ischemia cardiomyopathy: ICM, n=63) and control patients (n=48) were enrolled from Feb to Sep in 2017. Serum L-carnitines were quantitatively measured by liquid chromatography/ mass spectrometry. All patients underwent follow-up (mean 30.8 months). Multi-variable Cox survival was performed to verify the impact of carnitines on heart failure mortality prediction.

Results

A total of 27 different carnitine derivates were detected. Compared with control group, 26 types of carnitines were increased significantly in heart failure patients. Several circulating carnitines were independent biomarkers for heart failure even adjusted by multi-variable logistic analysis. We also found 7 carnitines were obviously increased in DCM group than those in ICM group. Isobutyryl-L-carnitine and stearoyl-L-carnitine were independently associated with higher probability of DCM than ICM. DCM prediction model established by adding carnitines (isobutyryl-L-carnitine and stearoyl-L-carnitine) to age, serum creatinine and left ventricular ejection fraction,had favorable discrimination (C-index = 0.832, P&lt;0.01, Figure 1A and B) and calibration efficiency (Hosmer-Lemeshow χ2=7.376, P=0.497&gt;0.05).

Meanwhile, a total of 43 mortality event occurred, 18 death (31.6%) in ICM group and 25 (27.2%) in DCM group. Independent clinical risk factors for the occurrence of mortality were serum creatinine &gt;2mg/dl, left atrial diameter 0.55mm and N-terminal pro-B-type natriuretic peptide &gt;4000 pg/ml. Using multi-variable COX survival analysis simultaneously adjusted by serum creatinine, left atrial diameter, NT-pro-BNP and age, oleoyl L-carnitine &gt;300nmo/L (HR=2.364, 95% CI: 1.122–4.976, P=0.024) and isovaleryl-L-carnitine &lt;100nmol/L (HR=2.108, 95% CI: 1.091–4.074, P=0.026) were also independently associated with higher mortality.

Conclusions

As one of critical participants in fatty acid metabolism, L-carnitines alteration not only differentiates DCM patients from ICM ones, but also independently predicts the risk of long-term mortality in heart failure patients.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Natural Science Foundation of China, Grant of Shanghai Municipal Commission of Health and Family Planning

Suppressions of vibration in the Tip-Tilt mirror control system by add-on controller

Tip-Tilt mirrors play an important role in astronomical telescopes requiring the tracking performance at the level of microradian or sub-microradian. However, the closed-loop performance suffers a lot from the low-sample rate and time delay of image sensors. Especially, this issue is under the condition of vibrations, because dynamic behaviors are complex and the models are difficult to be obtained accurately. Another challenging issue comes from the measurement of vibrations and its extraction for the closed-loop control. This paper proposes a new method based on an add-on controller of the Tip-Tilt mirror to mitigate telescope vibrations. The proposed method only uses Tip-Tilt errors from an image sensor to implement a disturbance observer, which is not being restricted by an accurate model. As a result, the closed-loop performance can be optimized by designing of a proper Q-filter. To suppress the low-frequency and high-frequency vibrations, a novel Q-filter combining a lowpass filter and a bandpass filter is proposed here. The improved control method is validated by both simulation and experiment in the tip-tilt mirror control system under the condition of vibrations.

miR-137 alleviates focal cerebral ischemic injury in rats by regulating JAK1/STAT1 signaling pathway

The repairing effect and potential mechanism of miR-137 on cerebral ischemic injury in rats was investigated. The volume of cerebral infarction and calculated brain water content was detected by triphenyltetrazolium chloride staining. The expression of inflammatory factors was detected by enzyme-linked immunosorbent assay. The pathological damage of brain tissue was analyzed by hematoxylin and eosin and Nissl staining. The apoptosis in ischemic brain tissue was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling. The levels of STAT1 and JAK1 proteins were analyzed by Western blot. The expression of miR-137 in primary hippocampal neurons was detected by reverse transcription polymerase chain reaction. miR-137 overexpression significantly improved brain damage in rats. miR-137 overexpression can reduce the expression of TNF-α, IL-1β, and IL-6. miR-137 overexpression can reduce the degree of brain tissue damage and inhibit the expression of JAK1 and STAT1 proteins. miR-137 overexpression can reduce oxygen-glucose deprivation (OGD)/R-induced cell damage, improve cell proliferation, and reduce apoptotic rate. JAK1 and STAT1 protein expression was inhibited in hippocampal neurons after OGD/R treatment after transfection with miR-137 mimic. After the addition of the Filgotinib inhibitor, the levels of JAK1 and STAT1 proteins were significantly reduced. The results suggested that miR-137 overexpression can effectively improve ischemic injury after focal cerebral ischemia and protect against by inhibiting JAK1/STAT1 pathway.

Compensation factors for 3rd order coma in three mirror anastigmatic (TMA) telescopes

Misalignment induced third-order coma with respect to misaligned parameters in TMA optical systems is derived by using Nodal Aberration Theory, which yields the compensation factors that can be used to accomplish coma compensation in both coaxial and off-axis misaligned TMA telescopes. By using the compensation factors, coma free point for the tertiary mirror in TMA telescopes is derived and proved to be the negative form of the one for the secondary mirror in the Cassegrain telescope. The compensation factors can also be used to design the off-axis TMAs due to their capability of eliminating the coma over the field of view.

Evaluation of mango saponin in broilers: effects on growth performance, carcass characteristics, meat quality and plasma biochemical indices

OBJECTIVE

The objective of the present study was to determine whether mango saponin (MS) could be used as a feed additive in broiler chicks by evaluating growth performance, carcass characteristics, meat quality, and plasma biochemical indices.

METHODS

A total of 216 1-d-old Arbor Acres male broiler chicks were randomly assigned into three dietary treatments supplemented with 0 (control), 0.14% (MS 0.14%), or 0.28% (MS 0.28%) MS. Each treatment had six replicates (cages) with 12 chicks each. The feeding trial lasted for six weeks.

RESULTS

Compared with the control, dietary supplemented with 0.14% or 0.28% MS increased average daily weight gain of chicks in the grower (22 to 42 d) and the whole (1 to 42 d) phases, and the final body weight of chicks on d 42 was higher in MS supplemented groups (p<0.05). Lower L45 min* (lightness) and L24 h* values, lower b24 h* (yellowness) value, and higher a45 min* (redness) and a24 h* values of the breast muscle were observed in chicks fed with 0.28% MS on d 42 (p<0.05). The total antioxidant capacity in plasma increased in MS 0.14% group on d 21 (p<0.001). Lower contents of plasma total cholesterol and triglyceride were observed in chicks fed with 0.28% MS on d 21 and d 42, whereas the group supplemented with 0.14% MS only decreased plasma triglyceride content on d 21 (p<0.05). The glucose content in plasma decreased in MS 0.28% group on d 42 (p<0.001).

CONCLUSION

Overall, MS could be used as a feed additive in broiler chicks, and the supplemental level of 0.28% MS in diet could improve growth performance, meat quality, and plasma lipid metabolism in broiler chicks.

[The characteristic of lexical tone perception in native Mandarin speakers with mild and moderate sensorineural hearing loss]

Objective:To explore the characteristic of lexical tone perception in native-Mandarin speakers with mild to moderate sensorineural hearing loss. Method:Three types of continuum(Tone1/tone2, tone1/tone4 and tone2/tone3) were constructed and each of them includes a 15 stimuli. All speech stimuli in these three continua were resynthesized by applying the Pitch-Synchronous OverLap and Add(PSOLA) method implemented in Praat to the same mandarin syllable, /a/, with a high level tone produced by a female native-mandarin speaker. Twenty-three native-mandarin sensory hearing loss people were recruited for this study and identification task was used to acquire the tonal perceptual data. SPSS 19.0 software was used to get the fitting curves of lexical tone perception. Result:①Each tone perception curves owns the characteristic of categorical perception, including an obvious boundary, a definite intersection and the abrupt performance change at intersection. The tone perception curves were S-shape in SNHL people which were same as that in normal hearing people.②No significant performance difference of each continuum was observed between SNHL and NH in this study(P=0.811 in T1/T2 continuum, P=0.528 in T1/T4 continuum, P=0.555 in T2/T3 continuum). Conclusion:There is the categorical perception of lexical tone identification in native-mandarin sensorineural hearing loss people. The slight damage in peripheral auditory system did not changed characteristic of lexical tone perception.

Effects of Neuromedin S on the Proliferation of Splenic Lymphocytes and the Cytokine Secretion by Pulmonary Alveolar Macrophages in Pigs in vitro

Neuromedin S (NMS), a 36-amino acid neuropeptide, has been found to be involved in the regulation of the endocrine activity. It has been also detected in immune tissues in mammals, what suggests that NMS may play an important role in the regulation of immune response. The aim of this study was to demonstrate the presence of NMS receptor 1 (NMU1R) and effect of NMS in pig splenic lymphocytes (SPLs) and pulmonary alveolar macrophages (PAMs). The presence of NMU1R in pig SPLs and PAMs was respectively confirmed by reverse transcription-polymerase chain reaction (RT-PCR), western blot analysis and immunocytochemical methods. Furthermore, SPL proliferation was analyzed using the 3-(4,5)-dimethyl-thiahiazo-(-2-yl)-3,5-di-phenytetrazoliumromide (MTT) method. Additionally, the secretion of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in PAMs was all measured by enzyme-linked immunosorbent assay (ELISA) kits. In the present study, the results of RT-PCR and western blot analysis revealed that NMU1R mRNA and protein were both expressed in pig SPLs and PAMs, and the immunocytochemical investigations further revealed that the positive signal of NMU1R immunoreactivity was observed in plasma membranes of both SPLs and PAMs. In the in vitro study, we found that at concentrations of 0.001-1000 nM NMS alone or combined with lipopolysaccharide or phytohemagglutinin significantly increased SPL proliferation. Application of ELISA method showed that NMS could induce the secretion of the pro-inflammatory cytokines IL-1β, IL-6 and TNF-α in PAMs. These results suggest that NMS can act as a potently positive pro-inflammatory factor and immunomodulatory agent that affects the immune response of immune cells by combining with its receptor NMU1R.

Estradiol-tethered micropatterned surfaces for the study of estrogenic non-genomic pathways

Besides its well-known hormonal effects initiated in the nucleus, estradiol (E2) also activates non-nuclear pathways through interactions with receptors located on the cell plasma membrane. Micropatterned substrates consisting of gold dots bearing tethered E2 distributed on a cell-adhesive substrate were prepared and shown to trigger specifically E2 non-genomic effects in cells grown on the substrates.

Evidence for Octupole Correlations in Multiple Chiral Doublet Bands

Two pairs of positive-and negative-parity doublet bands together with eight strong electric dipole transitions linking their yrast positive- and negative-parity bands have been identified in ^{78}Br. They are interpreted as multiple chiral doublet bands with octupole correlations, which is supported by the microscopic multidimensionally-constrained covariant density functional theory and triaxial particle rotor model calculations. This observation reports the first example of chiral geometry in octupole soft nuclei.

Two-party secret key distribution via a modified quantum secret sharing protocol

We present and demonstrate a novel protocol for distributing secret keys between two and only two parties based on N-party single-qubit Quantum Secret Sharing (QSS). We demonstrate our new protocol with N = 3 parties using phase-encoded photons. We show that any two out of N parties can build a secret key based on partial information from each other and with collaboration from the remaining N - 2 parties. Our implementation allows for an accessible transition between N-party QSS and arbitrary two party QKD without modification of hardware. In addition, our approach significantly reduces the number of resources such as single photon detectors, lasers and dark fiber connections needed to implement QKD.

Overregulation of microRNA-212 in the poor prognosis of esophageal cancer patients

There have been few reports evaluating the expression and function of the microRNA miR-212 in esophageal cancer. The aim of this study was to investigate the relationship between miR-212 expression and clinicopathological factors and prognoses of esophageal cancer. MicroRNA was extracted from 46 esophageal cancer patients using the Taqman MicroRNA assay. All patients were at the same tumor node metastasis stage, but with different prognoses, and had all undergone surgery. The correlation between miR-212 expression and clinicopathological features was analyzed and the significance of miR-212 as a prognostic factor as well as its relationship with survival was determined. miR-212 expression was higher in patients with poor prognoses than in those with good prognoses (P < 0.0001). Kaplan-Meier analysis results showed that the miR-212 expression level was significantly correlated with survival time (P = 0.024). Patients with higher expression of miR-212 showed longer survival times. Cox multi-factor model analysis showed that miR-212 expression was significantly correlated with survival time (P = 0.026). mir-212 is related with prognostic factors and survival time and may be a biomarker for esophageal cancer.

Implications of microRNA-197 downregulated expression in esophageal cancer with poor prognosis

The aim of this study was to investigate the significance of the microRNA miR-197 expression level in relation to clinicopathological factors and prognoses of esophageal cancer (EC). MicroRNA was extracted using the Taqman(®) MicroRNA Assay from 46 EC patients at the same tumor node metastasis (TNM) stage, but with different prognoses, who underwent surgery. Paracancerous normal tissues were used as controls. The correlation between miR-197 expression and clinicopathologic features was analyzed, and the significance of miR-197 as a prognostic factor and its relationship with survival was determined. miR-197 expression was lower in patients with poor prognosis than in those with good prognosis (P < 0.05). Kaplan-Meier analysis results showed that the miR-197 expression level is significantly correlated with survival time (P = 0.030), and that patients with higher expression of miR-197 had longer survival times. Cox multi-factor model analysis showed that patient prognosis (P = 0.001), tumor length (P = 0.010) and expression (P = 0.042), and survival time were significantly correlated, with corresponding risks of 9.183, 2.318, and 1.925, respectively. This study supports a role of miR-197 as an anti-oncogene and a biomarker for EC and its relationship with other prognostic factors and survival.

A versatile stable platform for multifunctional applications: synthesis of a nitroDOPA–PEO–alkyne scaffold for iron oxide nanoparticles

A simple but powerful design of contemporary magnetic nanoparticle composites for biomedical applications.

Evidence for multiple chiral doublet bands in 133Ce

Two distinct sets of chiral-partner bands have been identified in the nucleus 133Ce. They constitute a multiple chiral doublet, a phenomenon predicted by relativistic mean field (RMF) calculations and observed experimentally here for the first time. The properties of these chiral bands are in good agreement with results of calculations based on a combination of the constrained triaxial RMF theory and the particle-rotor model.

Nitrogen metabolism and recycling in yaks (Bos grunniens) offered a forage - concentrate diet differing in N concentration

An experiment was conducted to characterise N use efficiency and quantify urea fluxes in yaks offered four levels of dietary N (1.43%, 1.97%, 2.45% and 2.90% of diet DM) in a 4 × 4 Latin square design. The incremental increase in N intake linearly increased N retention (P = 0.003) and the excretion of urinary N (P < 0.001), but no difference (P > 0.05) in faecal N excretion was observed in growing yaks fed any of the four diets. Microbial N production had quadratic (P < 0.001) responses to dietary N, characterised by the highest microbial N production occurring in the 1.97% N diet (P < 0.05). As the N content of the diet increased, the urinary excretion of urea increased from 13% to 27% of urea entry rate (quadratic, P < 0.001), whereas gastrointestinal entry urea returned to ornithine cycling decreased from 46% to 40% (linear, P < 0.001), and the gastrointestinal entry urea used for anabolism increased from 50% to 56% (linear, P < 0.001). Gastrointestinal entry urea incorporated into bacterial N decreased linearly (P < 0.001) with incremental increase in N intake, and the greatest concentration (23.5%) of bacterial N originating from plasma urea N was in yaks fed the 1.43% N diet. As much as 87% of the urea synthesised in the liver was returned to the gastrointestinal tract when the yaks were fed a diet with 1.43% N (1.1 times the maintenance N level). Moreover, constantly greater urea production than the intake of digestible N, and the gastrointestinal-urea clearance than the kidney-urea clearance were observed, respectively, in the growing yaks, regardless of the level of N intake. These results suggest that yaks might be more efficient at utilising N under harsh environment than are cattle.

Gene-dependent cell death in yeast

Caspase-dependent apoptotic cell death has been extensively studied in cultured cells and during embryonic development, but the existence of analogous molecular pathways in single-cell species is uncertain. This has reduced enthusiasm for applying the advanced genetic tools available for yeast to study cell death regulation. However, partial characterization in mammals of additional genetically encoded cell death mechanisms, which lead to a range of dying cell morphologies and necrosis, suggests potential applications for yeast genetics. In this light, we revisited the topic of gene-dependent cell death in yeast to determine the prevalence of yeast genes with the capacity to contribute to cell-autonomous death. We developed a rigorous strategy by allowing sufficient time for gene-dependent events to occur, but insufficient time to evolve new populations, and applied this strategy to the Saccharomyces cerevisiae gene knockout collection. Unlike sudden heat shock, a ramped heat stimulus delivered over several minutes with a thermocycler, coupled with assessment of viability by automated counting of microscopic colonies revealed highly reproducible gene-specific survival phenotypes, which typically persist under alternative conditions. Unexpectedly, we identified over 800 yeast knockout strains that exhibit significantly increased survival following insult, implying that these genes can contribute to cell death. Although these death mechanisms are yet uncharacterized, this study facilitates further exploration.

Role of taurine supplementation to prevent exercise-induced oxidative stress in healthy young men

To evaluate the protective effects of taurine supplementation on exercise-induced oxidative stress and exercise performance, eleven men aged 18-20 years were selected to participate in two identical bicycle ergometer exercises until exhaustion. Single cell gel assay (SCG assay) was used to study DNA damage in white blood cells (WBC). Pre-supplementation of taurine, a significant negative correlation was found between plasma taurine concentration before exercise and plasma thiobaribituric-acid reactive substance (TBARS) 6 hr after exercise (r = -0.642, p<0.05). WBC showed a significant increase in DNA strand breakage 6 hr and 24 hr after exercise. Seven-day taurine supplementation reduced serum TBARS before exercise ( p<0.05) and resulted in a significantly reduced DNA migration 24 hr after exercise ( p<0.01). Significant increases were also found in VO(2)max, exercise time to exhaustion and maximal workload in test with taurine supplementation ( p<0.05). After supplementation, the change in taurine concentration showed positive correlations with the changes in exercise time to exhaustion and maximal workload. The results suggest that taurine may attenuate exercise-induced DNA damage and enhance the capacity of exercise due to its cellular protective properties.

Redox factor-1: an extra-nuclear role in the regulation of endothelial oxidative stress and apoptosis

The rac1 GTPase promotes oxidative stress through reactive oxygen species (ROS) production, whereas the DNA repair enzyme and transcriptional regulator redox factor-1 (ref-1) protects against cell death due to oxidative stimuli. However, the function of ref-1 in regulating intracellular oxidative stress, particularly that induced by rac1, has not been defined. We examined the role of ref-1 in vascular endothelial cell oxidative stress and apoptosis. Ref-1 was expressed in both the cytoplasm and nuclei of resting endothelial cells. Cytoplasmic ref-1 translocated to the nucleus with the oxidative trigger hypoxia/reoxygenation (H/R). Forced cytoplasmic overexpression of ref-1 suppressed H/R-induced oxidative stress (H(2)O(2) production), NF-kappaB activation, and apoptosis, and also mitigated rac1-regulated H(2)O(2) production and NF-kappaB transcriptional activity. We conclude that inhibition of oxidative stress is another mechanism by which ref-1 protects against apoptosis, and that this is achieved through modulation of cytoplasmic rac1-regulated ROS generation. This suggests a novel extra-nuclear function of ref-1.

Biodegradation of volatile organic compounds by five fungal species

Five fungal species, Cladosporium resinae (ATCC 34066), Cladosporium sphaerospermum (ATCC 200384), Exophiala lecanii-corni (CBS 102400), Mucor rouxii (ATCC 44260), and Phanerochaete chrysosporium (ATCC 24725), were tested for their ability to degrade nine compounds commonly found in industrial off-gas emissions. Fungal cultures inoculated on ceramic support media were provided with volatile organic compounds (VOCs) via the vapor phase as their sole carbon and energy sources. Compounds tested included aromatic hydrocarbons (benzene, ethylbenzene, toluene, and styrene), ketones (methyl ethyl ketone, methyl isobutyl ketone, and methyl propyl ketone), and organic acids ( n-butyl acetate, ethyl 3-ethoxypropionate). Experiments were conducted using three pH values ranging from 3.5 to 6.5. Fungal ability to degrade each VOC was determined by observing the presence or absence of visible growth on the ceramic support medium during a 30-day test period. Results indicate that E. lecanii-corni and C. sphaerospermum can readily utilize each of the nine VOCs as a sole carbon and energy source. P. chrysosporium was able to degrade all VOCs tested except for styrene under the conditions imposed. C. resinae was able to degrade both organic acids, all of the ketones, and some of the aromatic compounds (ethylbenzene and toluene); however, it was not able to grow utilizing benzene or styrene under the conditions tested. With the VOCs tested, M. rouxiiproduced visible growth only when supplied with n-butyl acetate or ethyl 3-ethoxypropionate. Maximum growth for most fungi was observed at a pH of approximately 5.0. The experimental protocol utilized in these studies is a useful tool for assessing the ability of different fungal species to degrade gas-phase VOCs under conditions expected in a biofilter application.

[Effect of the Purariae-isofiavones on atrophic nasal mucosas in ovariectomized rats]

OBJECTIVE

To study the effect of Purariae-isoflavone on atrophic nasal mucosas in ovariectomized rats.

METHOD

60 rats were divided into four groups randomly, every group with 15 rats. The first group was studied as normal control group. Rats of the second group were ovariectomized and not given any treatment. Rats of the third group were given Weinian by gastrogavage from 30 days after being ovariectomized to being killed. Rats of the forth group were given purariae isoflavone by gastrogavage from 30 days after operation to being killed. Level of Estrodiol (E2) of every rat was measured. Morphological changes of the nasal mucosas were observed by light-microscopy and electron-microscopy.

RESULT

30 days after being ovariectomized, atrophic nasal mucosas occured, and average E2 level was lower significantly than that of control group (P < 0.05). Atrophic mucosas recovered after being treated with Weinian or Purariae isoflavone. E2 level of the third group was lower significantly than that of the first group and the second group (P < 0.05). E2 level of the forth group recovered (P > 0.05).

CONCLUSION

Purariae-isoflavone have effects on treating the atrophic nasal mucosas and recovering E2 level in ovariectomized rats.

Link of a new type of apoptosis-inducing gene ASY/Nogo-B to human cancer

Although apoptosis plays an essential role in the embryogenesis and homeostasis of multicellular organisms, this mechanism has not yet been fully clarified. We isolated a novel human apoptosis-inducing gene, ASY, which encodes an endoplasmic reticulum-targeting protein without any known apoptosis-related motifs. This gene is identical to the Nogo-B, a splice variant of the Nogo-A which has recently been shown to be an inhibitor of neuronal regeneration in the central nervous system. Ectopic expression of the ASY gene led to extensive apoptosis, particularly in cancer cells. Furthermore, transcription of the ASY gene was suppressed in small cell lung cancer. These results suggest that a new type of apoptosis-inducing gene, namely, ASY, may be involved in the development of certain types of cancer.

Study on apoptosis and expression of P53, bcl-2, Bax in cardiac myocytys of congestive heart failure induced by ventricular pacing

The apoptosis and the expression of p53, bcl-2 and Bax in myocytes of chronic rapid ventricular pacing-induced congestive heart failure (CHF) in rabbits were investigated. The CHF rabbit model (P, n = 7) was established by chronic rapid ventricular pacing for 3 weeks. By using TUNEL technique the apoptosis in the myocytes in the rabbit model was studied and the expression of p53, bcl-2 and Bax in myocytes was detected by using immunohistochemical method. Sham-operated (C, n = 9) group served as control group. The results showed that there were about 4033 +/- 884.56 apoptotic cells/10(6) myocytes in P group, but no apoptotic cells were found in C group. Myocytes positive for p53 immunoreactivity (18.86 +/- 8.48 vs 5.06 +/- 0.87, P < 0.01) and positive for Bax immunoreactivity (7.15 +/- 1.91 vs 0.43 +/- 0.09, P < 0.01) were increased in P group as compared with those in C group, while the myocytes positive for bcl-2 immunoreactivity (7.08 +/- 1.05 vs 14.97 +/- 4.47, P < 0.01) and the ratio of bcl-2/Bax were decreased in P group as compared with those in C group. Apoptosis was involved in the development of CHF induced by continuously rapid ventricular pacing in rabbit. The expression of p53 and Bax was increased, while the expression of bcl-2 was inhibited. These might play an important role in the acceleration of the apoptosis.

Effect of cooking on banana and plantain texture

The effect of temperature and duration of cooking on plantain and banana fruit texture and cytpoplasmic and cell wall components was investigated. The firmness of both banana and plantain pulp tissues decreased rapidly during the first 10 min of cooking in water above 70 degrees C, although plantain was much firmer than banana. Cooking resulted in pectin solubilzation and middle lamella dissolution leading to cell wall separation (as observed by SEM). Dessert banana showed more advanced and extensive breakdown than plantain. Although dessert banana had a higher total pectin content than plantain, the former had smaller-sized carboxyethylenediaminetetraacetic acid (CDTA) soluble pectic polymers which are associated with plant tissues that have a propensity to soften. Plantain had higher levels of starch and amylose than banana but this was associated with a firmer fruit texture rather than a softening due to cell swelling during starch gelatinization. Different cooking treatments showed that cooking in 0.5% of CaCl(2) solution and temperatures below 70 degrees C had significant effects on maintenance of pulp firmness.

Molecular characterisation of the Theileria buffeli/orientalis group

Benign bovine Theileria parasites known as either Theileria buffeli, Theileria orientalis or Theileria sergenti are classified on basis of their morphology, vector specificity, pathogenicity and 18S small subunit ribosomal RNA or major piroplasm protein (MPSP) sequences. Since most isolates have been characterized on only some of these criteria and the existing confusion in nomenclature, an analysis was performed on eight different isolates to combine 18S rRNA data with MPSP data and the results were compared with available biological parameters. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach for both genes was used in combination with reverse line blot hybridisation for the 18S rRNA gene. Both MPSP and 18S rRNA genes were cloned and sequenced from parasites displaying aberrant MPSP RFLP profiles. Phylogeny based on published and determined 18S rRNA and MPSP sequences did correlate within the same isolate but there was no obvious correlation between molecular and biological data. Based on these findings, we suggest that the appropriate name for all these parasites is Theileria buffeli. A more specific nomenclature should be assigned when new molecular markers may become available.

Supraceliac aortic clamping during the anhepatic phase of experimental orthotopic liver transplantation

BACKGROUND

The pig tolerates simultaneous clamping of the liver pedicle and inferior vena cava poorly, so venovenous bypass has to be used during the anhepatic phase of experimental orthotopic liver transplantation (OLT). The aim of this work is to assess whether clamping of the supracoeliac aorta during the anhepatic phase (AP) of experimental OLT in pigs allows transplantation in stable hemodynamic conditions.

METHODS

Fourteen pigs (weight, 16 to 18 kg) received whole liver grafts from 14 age-matched donors and were subsequently divided into two groups: group I, OLT without venovenous bypass during the AP, group II, OLT with supracoeliac aortic clamping during the AP. Variables analyzed were cardiac output (CO) and related variables, mean systemic arterial pressure (MAP), mixed venous oxygen saturation (SvO2), hepatic artery and portal vein blood flow, systemic and hepatic O2 supply and uptake (SDO2, SVO2, HDO2, HVO2, respectively), liver enzymes, glucose, creatinine, and electrolytes.

RESULTS

In group I, CO, MAP, and SvO2, decreased during the AP (anhepatic) in comparison with baseline (preanhepatic) values (CO, 3.60+/-0.74, preanhepatic, v. 1.21+/-0.25 L x min(-1), anhepatic; P<.05. MAP, 97+/-12, preanhepatic, v. 43+/-17 mm Hg, anhepatic; P<.05. SvO2, 91.6+/-5.6, preanhepatic v. 70.0+/-12.5%, anhepatic; P<.05), and SDO2/SVO2 increased by 16% (preanhepatic) to 33% (anhepatic; P<.05). In group II, CO decreased during the anhepatic phase by only 21% (3.82+/-0.81, preanhepatic, v. 3.07+/-0.99 L x min(-1), anhepatic; not significant), the MAP increased significantly (100+/-8, preanhepatic, v. 135+/-4 mm Hg, anhepatic; P<.05), and SVO2, SDO2, SVO2, and SDO2/SVO2 remained unchanged. After revascularization, none of these variables differed significantly between groups, and levels of liver enzymes, glucose, creatinine, urea, and electrolytes were similar in both groups, both before and aftertransplantation.

CONCLUSIONS

Experimental OLT can be carried out in pigs without venovenous bypass, but it leads to severe hemodynamic disturbances. Clamping of the supraceliac artery during the AP is well tolerated and results in excellent hemodynamic stability, so it may prove to be a useful technique in liver transplantation in animals, such as dogs or pigs, that do not tolerate simultaneous clamping of the liver pedicle and inferior vena cava as well as human beings.

Tumorigenic conversion resulting from inhibition of apoptosis in a nontumorigenic HeLa-derived hybrid cell line

Although tumorigenicity in nude mice is one of the most important transformed phenotypes, its mechanism has been little analyzed. To understand the molecular basis of tumorigenicity, we characterized nontumorigenic CGL1 and tumorigenic CGL4 cell lines, both of which were originated from a common ancestral HeLa-human diploid fibroblast hybrid cell clone and retained a malignant state except tumorigenicity. When injected into nude mice, nontumorigenic CGL1 cells underwent apoptosis, but tumorigenic CGL4 cells did not. In vitro, CGL1 was also less resistant to various apoptotic stimuli than CGL4. These results suggested that inhibition of apoptosis may lead to tumorigenicity. To examine this hypothesis, we introduced antiapoptotic genes into the CGL1 cell line and injected the resulting clones into nude mice. The results showed that the ectopic expression of Bcl-2 or E1B19k, but not of crmA, converted CGL1 cells to tumorigenicity, suggesting strongly that this phenotype may be conferred by evasion of apoptosis.

A novel strategy for construction of immuno-PCR gene probe and its preliminary application in diagnosis

An alpha-fetoprotein (AFP) antibody gene probe was constructed using chlorophyll molecule as a coupler between protein and dsDNA. The preliminary study on the detection of AFP using this novel probe was performed by immuno-PCR. and the results indicated that the sensitivity of the gene probe by immuno-PCR is 10(4)-10(5) times higher compared with ELI SA. The construction of immuno-PCR gene probe in this way not only completely prevents the protein from contacting with organic solvent and maintains the native conformation of the proteins, but also anchors protein to dsDNA in a fixed orientation and makes PCR amplification more efficient. The gene probe thus constructed is stable for at least 6 months at room temperature. This new approach is exquisite, simple, less expensive, and suitable to a variety of applications.

Identification of diaphragmatic crural component of gastroesophageal barrier in the rat

Manometric assessment of the diaphragmatic contribution to the human gastroesophageal barrier is difficult because it overlaps with that of the lower esophageal sphincter. Our aim was to investigate the barrier components in the rat in which the gastroesophageal junction is widely separated from the hiatus. Rats under anesthesia (N = 119) and after muscle relaxation (N = 14) underwent stationary and pull-through perfusion manometry. Inspiratory transdiaphragmatic pressure gradient was 5.79 +/- 1.69 mm Hg and lower esophageal sphincter pressure was 14.76 +/- 8.63 mm Hg. A 13.78 +/- 3.13-mm intraabdominal segment of the esophagus was interposed cranially between the sphincter and a group of phasic oscillations with frequency identical to the respiratory rate and pressure of 13.81 +/- 6.54 mm Hg, which disappeared after muscle relaxation. Both components of the gastroesophageal barrier in the rat are widely separated by a long intraabdominal esophagus. This arrangement allows investigation of the behavior of both components under challenging conditions.

Nucleotide sequence of a 5423 base pairs fragment of the LsNPV genome and comparison with the AcNPV genome

A 5423 bp fragment of LsNPV genome was sequenced, in which PDV-E66 gene and another four ORFs were found. The PDV-E66 gene of LsNPV was compared with the PDV-E66 gene of AcNPV, and a 51.9% nucleotide sequence homology and 38.8% amino acid sequence homology were found between the two genes. Two conserved late transcriptional motifs TAAG were found in LsNPV PDV-E66 gene, similar to those in AcNPV PDV-E66. The LsNPV PDV-E66 ORF is 204 base pairs shorter than the AcNPV PDV-E66 ORF at the 5' end. This is agreement with the fact that the N-terminus of the AcNPV PDV-E66 mature protein is 69 amino acids interior to the N-terminus predicted by the AcNPV PDV-E66 ORF. The 5' regulatory region of ORF1 contains early (CGTGC) and late (TAAG) transcriptional initiation motifs and ORF1 is predicted to encode a protein with 114 amino acid residues. The 5' regulatory region of ORF2 which can encode a protein with 115 amino acid residues contains only an early transcriptional initiation motif. Compared with all the genes from AcNPV and other baculoviruses, ORF1 and ORF2 have no homologous genes. It is suggested that ORF1 and ORF2 may be two novel baculovirus genes. ORF3 (PDV-E66 gene), ORF5 and an incomplete ORF, ORF6-part, have homologous regions in the AcNPV genome. ORF3, ORF5, ORF6-part are linked together in LsNPV genome, but their homologous regions are separated by about 58 kb fragment in the AcNPV genome. This fact indicates that the organization of the above genes in LsNPV is different from that of AcNPV. ORF4 is included in ORF6-part and can encode a 48 amino acid residues polypeptide, but ORF4 and ORF6-part are located on different DNA strands.

The effect of hepatic vascular exclusion on hepatic blood flow and oxygen supply--uptake ratio in the pig

The hemodynamic disturbances produced by total hepatic vascular exclusion (THVE) for 40 minutes were studied in 7 pigs (19-22 kg). THVE was produced by clamping the hepatic pedicle and inferior vena cava, above and below the liver, for a 40-minutes period, followed by unclamping. Compared to baseline values, 30 minutes after onset of THVE, there was a decrease in cardiac output (3.86 +/- 0.55 vs 1.23 +/- 0.23 L x min-1), systemic arterial pressure (97.54 +/- 13.58 vs 43.43 +/- 11.38 mm Hg), and pulmonary artery pressure (16.57 +/- 6.38 vs 12.57 +/- 3.58) and an increase in systemic and pulmonary vascular resistance (1772 +/- 198 vs 2351 +/- 462, and 182 +/- 66 vs 361 +/- 124 dyn x s x cm-5 respectively). As a result of diminished cardiac output, the systemic oxygen supply decreased (461 +/- 131 vs 101 +/- 46 ml x min-1), but the systemic oxygen extraction rate rose from 17.3% t0 31.2%. Thirty minutes after unclamping, the changes had reversed and all the parameters tended to normalize. Total hepatic blood flow 30 minutes after unclamping was higher than at baseline (5.08 +/- 1.2 vs 6.66 +/- 0.67 ml x min-1 x 100 g-1), because of the increase in portal blood flow (4.52 +/- 1.21 vs 6.07 +/- 0.70 ml x min-1 x 100 g-1). There were no significant differences in hepatic oxygen supply and uptake at baseline and after unclamping (152.6 +/- 23.0 vs 187.0 +/- 34.7 and 22.7 +/- 4.9 vs 28.7 +/- 8.4 ml O2 respectively). AST rose (29 +/- 7 vs 136 +/- 91 U/l), but there was no change in the remaining liver enzymes, glucose, creatinine and serum electrolytes, so we conclude that the hemodynamic disturbances produced by 40 minutes of THVE are manageable and spontaneously reversible. Liver metabolism was not greatly disturbed, so THVE was judged to be a viable technique to be added to the surgeon's range of options.

Extremely low awareness of AIDS, sexually transmitted diseases and condoms among Dai ethnic villagers in Yunnan province, China

OBJECTIVE

To assess the awareness of AIDS, other sexually transmitted diseases (STDs), condoms, sources of health information and HIV-related societal risks among Dai villagers in southern Yunnan Province, China.

SUBJECTS AND METHODS

In November-December 1994, a cross-sectional descriptive study, comprising a questionnaire-based survey and focus group discussions, was conducted in three Dai villages in Mengla county; a total of 177 Dai villagers were interviewed in the survey and eight focus group discussions were held. Ethnographic observations provided a composite picture of HIV risks in the area.

RESULTS

Only 18% of respondents had heard of AIDS, and only 25 and 28%, respectively, had heard of STDs or condoms. Furthermore, among these more aware groups, the level of knowledge was low and misconceptions were common. An ability to understand the official language (Mandarin) was the most important predictor of awareness of AIDS, other STDs or condoms. The sources of information in the three Dai villages sampled included TV, videos, radio and magazines, but only TV and videos had a large audience. Even so, these media were mostly in Mandarin and were not used in AIDS education. Travel outside of China was frequent; most villagers (77%) had traveled to Laos and 9% had traveled to Thailand. Societal risks of HIV transmission, such as an increasing incidence of STDs and an active sex industry, were observed in this area.

CONCLUSIONS

Dai villagers in southern Yunnan Province had an extremely low awareness and knowledge of AIDS, other STDs and condoms. Given the high mobility of ethnic villagers to neighboring countries in Southeast Asia and the societal risks of HIV transmission in this area, there is an urgent need to provide accessible education about AIDS and other STDs. Suggestions regarding such health education and the implications of HIV policy-making are discussed.

Thyroid hormones in the pathogenesis of lung hypoplasia and immaturity induced in fetal rats by prenatal exposure to nitrofen

BACKGROUND/PURPOSE

Nitrofen is believed to act on prenatally exposed fetuses by changing maternal or fetal thyroid hormone physiology. The aim of this study was to determine whether the amounts of circulating and lung tissue T3 and T4 are decreased in rat fetuses with nitrofen-induced pulmonary hypoplasia and diaphragmatic hernia.

METHODS

Timed-pregnant rats were given 100 mg of nitrofen in oil on gestational day 9.5, and their fetuses were recovered on the 21st day. Lung weight to body weight ratio was determined. Hormonal studies consisted in measurement of plasma T3, T4, and TSH, and of T3, T4, and DNA in lung tissue. Suitable groups of control fetuses prenatally exposed to oil were used for comparison.

RESULTS

The lungs of nitrofen-treated fetuses were hypoplastic and those who had congenital diaphagmatic hernia were even more so. Nitrofen treatment led to decreased plasma T3 and T4 levels without TSH changes. T3 and T4 in lung tissue were apparently decreased in treated fetuses when expressed by weight, but these differences disappeared when expressed by DNA (cell content).

CONCLUSIONS

Lung hypoplasia and immaturity induced by nitrofen treatment are not related to decreased levels of thyroid hormones in tissue near term. This should be kept in mind when proposing hormonal treatment for prenatal induction of lung maturation.

An experimental study on the pathogenesis of gastroesophageal reflux after repair of diaphragmatic hernia

BACKGROUND/PURPOSE

Gastroesophageal reflux (GER) is increasingly reported after surgical repair of congenital diaphragmatic hernia (CDH) and eventration. The aim of this study was to test the hypothesis that transdiaphragmatic pressure gradients are increased and that the antireflux barrier is weakened after plication of a previously paralyzed diaphragm.

METHODS

Abdominal and esophageal pressures as well as lower esophageal sphincter pressures (LESP) and diaphragmatic pinchcock pressure (DPP) were measured before and after diaphragmatic plication in 16 rats in which the diaphragm had been previously eventrated by phrenic nerve section.

RESULTS

This maneuver increased the transdiaphragmatic inspiratory pressure gradient from 2.75 +/- 0.54 to 4.51 +/- 0.86 mm Hg (P < .05) by rising both the inspiratory (-2.02 +/- 0.39 v -3.11 +/- 0.92 mm Hg, P < .05) and the expiratory (1.47 +/- 0.87 v 0.51 +/- 0.41 mm Hg, P < .05) intrathoracic pressures. At the same time, the antireflux barrier was weakened because LESP decreased from 17.5 +/- 5.59 to 10.59 +/- 5.74 mm Hg (P < .05) and DPP tended to decrease from 13.57 +/- 8.67 to 6.07 +/- 1.72 mm Hg (ns).

CONCLUSIONS

Plication of the previously paralyzed diaphragm in the rat reinforces the GER driving forces while weakening the antireflux barrier. This may explain why reflux is frequent in children surviving repair of diaphragmatic hernia and eventration.

Transdiaphragmatic pressure gradients and the lower esophageal sphincter after tight abdominal wall plication in the rat

BACKGROUND

Gastroesophageal reflux (GER) is increasingly recognized as a complication of surgical closure of gastroschisis and omphalocele.

AIM

This study tests the hypothesis that forceful abdominal wall closure reinforces the transdiaphragmatic pressure gradients that constitute the main GER-driving force and challenges the antireflux barrier.

MATERIALS AND METHODS

Abdominal and esophageal pressures as well as lower esophageal sphincter pressures (LESP) and length (LESL) were measured in 17 adult rats before tight abdominal wall plication, after it, and 1 week later.

RESULTS

This maneuver increased the transdiaphragmatic expiratory gradient from 0.67 +/- 1.31 to 6.97 +/- 2.68 mm Hg (P < .01) and the inspiratory gradient from 4.36 +/- 1.13 to 10.79 +/- 2.31 mm Hg (P < .01) by markedly increasing both the expiratory (from 1.47 +/- 0.74 to 9.44 +/- 1.85 mm Hg; P < .01) and inspiratory (from 0.98 +/- 0.69 to 6.83 +/- 1.55 mm Hg; P < .01) intraabdominal pressures. These changes were transient, and all pressures became normal after 1 week. The antireflux barrier functioned properly under these new conditions because both LESP and the diaphragmatic pinch-cock pressure (DPP) increased, from 20.3 +/- 3.63 to 26.5 +/- 4.31 mm Hg (P < .01) and from 16.4 +/- 7.25 to 22.5 +/- 4.36 mm Hg (P < .01), respectively, while LESL remained unchanged.

CONCLUSION

Tight abdominal wall plication in the rat generates high intraabdominal pressures and thus reinforces the transdiaphragmatic pressure gradients, but these conditions elicit a healthy barrier response with sphincteric reinforcement. In addition, these changes are transient and fade out some time after operation. These facts should be taken into account for understanding the pathogenesis of GER after repair of abdominal wall defects in human babies.