[A survey on the implementation of cardiovascular surgery for congenital heart disease in China between 2017 and 2021]

Objective: To investigate the inplementation of cardiovascular surgery for congenital heart disease (CHD) in China. Methods: A cross-sectional study was carried out. The CHD cardiovascular surgery data collected by the Chinese Society of Extracorporeal Circulation from 2017 to 2021 in 31 provinces (autonomous regions/municipalities) of China were retrospectively reviewed, the implementation of CHD cardiovascular surgery in different provinces, regions, general/specialized hospitals, and different age groups (whether≤18 years old) were summarized, and the correlation analysis between the number of surgeries carried out in each province/region and the gross regional product and the number of the regional population was performed. Results: Between 2017 and 2021, the annual volume of CHD cardiovascular surgery was 77 120, 77 634, 81 161, 62 663 and 71 492, respectively, showing a decreasing trend. Meanwhile, the proportion of CHD patients aged≤18 years who underwent cardiovascular surgery also showed a downward trend, from 79.8% (61 557/77 120) in 2017 to 58.6% (41 871/71 492) in 2021 (P=0.027). The number of surgical cases varied greatly among different provinces, including 4 provinces with≥5 000 cases and 9 provinces with 2 000-5 000 cases. In the five years, the number of CHD cardiovascular surgeries in Central and East China was the largest, accounting for 41.1%-45.5% of the total surgical cases. The proportion of CHD surgery cases≤18 years old was the highest in Southwest China (69.7%-87.4%) and the lowest in Northeast China (28.2%-68.9%). Except for 2021, the number of cases carried out by each region between 2017 and 2020 was correlated with the gross regional product (r=0.929, 0.929, 0.893 and 0.964, respectively, all P<0.05) and the population (r=0.821, 0.893, 0.821 and 0.857, respectively, all P<0.05). Hospitals that performed more than 100 operations (20.5%±1.2% of the total number of hospitals) completed 86.2%±1.2% of the total number of operations in China during the 5-year period. In 2017 and 2021, the number of CHD cardiovascular surgeries preformed in children's/women's and children's specialized hospitals accounted for 24.3% (18 772/77 120) and 23.8% (17 012/71 492) of the total number of cases in China, respectively. Conclusions: From 2017 to 2021, the number of cardiovascular surgery for CHD decreases slightly, but the proportion of surgery for adult CHD patients increases significantly.There is a strong correlation between the number of CHD operations in each region and their economic development status. The scale of CHD cardiovascular surgery performed in children's hospitals/women's and children's hospitals accounts for about a quarter of the total volume in China.

[Risk factors associated with in-hospital mortality in patients requiring extracorporeal membrane oxygenation in the perioperative period of heart transplantation]

Objective: To explore risk factors associated with in-hospital mortality in patients requiring extracorporeal membrane oxygenation (ECMO) in the perioperative period of heart transplantation. Methods: The data of ECMO cases in the perioperative period of heart transplantation from the Chinese Society of Extracorporeal Life Support (CSECLS) between January 2017 and December 2021 were retrospectively analyzed. These patients were divided into the survival group and non-survival group according to their outcomes at discharge. The demographics, indications and complications of ECMO between the two groups were compared, and the related risk factors of poor prognosis were analyzed. Results: A total of 77 patients were included in the study, including 67 males and 10 females, with a median age [M(Q₁, Q₃)] of 48 (36, 59) years. Sixty-three patients (81.8%) were successfully withdrawn from the ECMO and 46 patients (59.7%) survived to discharge. The median ECMO time was 139 (92, 253) hours. Compared with the survival group, the non-survival group (n=31) had more patients with chronic kidney disease before surgery [22.6% (7/31) vs 4.3% (2/46), P=0.034], and a higher proportion of continuous renal replacement therapy (CRRT) during ECMO [74.2% (23/31) vs 50.0% (23/46), P=0.034]. Moreover, the non-survival group had longer duration of extracorporeal circulation [262 (195, 312) vs 201 (155, 261) min, P=0.056] and higher lactate value in the first 24 hours of ECMO support [2.7 (2.1, 4.7) vs 2.3 (1.4, 3.8) mmol/L, P=0.060], but the differences were not statistically significant. Multivariate logistic regression analysis showed that perioperative application of CRRT was an independent risk factor for poor prognosis in ECMO patients during heart transplantation (OR=19.345, 95%CI: 1.209-309.440, P=0.036). Conclusion: CRRT treatment during ECMO is a risk factor for in-hospital mortality in patients undergoing heart transplantation.

[Application of pump-controlled retrograde trial off in weaning from veno-arterial extracorporeal membrane oxygenation in adult patients]

Objective: To Summarize the experience of pump-controlled retrograde trial off (PCRTO) in the process of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) withdrawal in adult patients. Methods: Adult patients who received ECMO assistance in Intensive Care Unit for Cardiac Surgery from March to July 2019 were collected. According to our strategies, PCRTO was used if the patients can wean from VA-ECMO and hemodynamic indexes were recorded during the process. The statistics data was collected, including the 48 hours survival rate, ECMO re-assistance rate, thrombus complications, Intensive Care Unit (ICU) stay time and hospital stay time after weaning from VA-ECMO. The patients who failed in the test were continued to be assisted by ECMO. Results: There were 46 patients assisted by VA-ECMO in our center. In total, 21 adults who met the offline test standard underwent 26 PCRTOs, including 10 male adults (47.6%), with an age of 65 (55, 68) years old. Eighteen adults passed the withdrawal test. No new thrombus was found in the arteriovenous ultrasound of the lower extremity after weaning from ECMO, and no pulmonary embolism was found in the chest X-ray. The success rate of weaning from ECMO was 69.23%(18/26). The D-dimer decreased [584(348,2 107)μg/L vs 1 440(631,2 916)μg/L, P=0.014] and the left ventricular ejection fraction (LVEF) increased (51.4%±8.5% vs 46.9%±10.6%, P=0.013) on the next day after weaning. There were significant differences in heart rate (HR), central venous pressure (CVP), oxygenation index and lactate (Lac) during the PCRTO in the group which involved the cases of the 8 failed experiments (all P<0.05). Compared with the failure group, there were significant differences in age, blood flow rate, CVP before the test, HR, pulse oxygen saturation(SpO(2)), CVP, Lac and oxygenation index after the test, and the variations of SpO(2), CVP and Lac. Conclusion: PCRTO is a simple, reversible, safe and effective weaning method. It can be used in the process of VA-ECMO withdrawal in adult patients.

Application of Artificial Intelligence/Machine Vision & Learning for the Development of a Live Single-cell Phenotypic Biomarker Test to Predict Prostate Cancer Tumor Aggressiveness

To assess the usefulness and applications of machine vision (MV) and machine learning (ML) techniques that have been used to develop a single cell-based phenotypic (live and fixed biomarkers) platform that correlates with tumor biological aggressiveness and risk stratification, 100 fresh prostate samples were acquired, and areas of prostate cancer were determined by post-surgery pathology reports logged by an independent pathologist. The prostate samples were dissociated into single-cell suspensions in the presence of an extracellular matrix formulation. These samples were analyzed via live-cell microscopy. Dynamic and fixed phenotypic biomarkers per cell were quantified using objective MV software and ML algorithms. The predictive nature of the ML algorithms was developed in two stages. First, random forest (RF) algorithms were developed using 70% of the samples. The developed algorithms were then tested for their predictive performance using the blinded test dataset that contained 30% of the samples in the second stage. Based on the ROC (receiver operating characteristic) curve analysis, thresholds were set to maximize both sensitivity and specificity. We determined the sensitivity and specificity of the assay by comparing the algorithm-generated predictions with adverse pathologic features in the radical prostatectomy (RP) specimens. Using MV and ML algorithms, the biomarkers predictive of adverse pathology at RP were ranked and a prostate cancer patient risk stratification test was developed that distinguishes patients based on surgical adverse pathology features. The ability to identify and track large numbers of individual cells over the length of the microscopy experimental monitoring cycles, in an automated way, created a large biomarker dataset of primary biomarkers. This biomarker dataset was then interrogated with ML algorithms used to correlate with post-surgical adverse pathology findings. Algorithms were generated that predicted adverse pathology with >0.85 sensitivity and specificity and an AUC (area under the curve) of >0.85. Phenotypic biomarkers provide cellular and molecular details that are informative for predicting post-surgical adverse pathologies when considering tumor biopsy samples. Artificial intelligence ML-based approaches for cancer risk stratification are emerging as important and powerful tools to compliment current measures of risk stratification. These techniques have capabilities to address tumor heterogeneity and the molecular complexity of prostate cancer. Specifically, the phenotypic test is a novel example of leveraging biomarkers and advances in MV and ML for developing a powerful prognostic and risk-stratification tool for prostate cancer patients.

Modeling and Simulation of A Microchannel Cooling System for Vitrification of Cells and Tissues

BACKGROUND

The microchannel heat exchange system has several advantages and can be used to enhance heat transfer for vitrification.

OBJECTIVE

To evaluate the microchannel cooling method and to analyze the effects of key parameters such as channel structure, flow rate and sample size.

MATERIALS AND METHODS

A computational flow dynamics model is applied to study the two-phase flow in microchannels and its related heat transfer process. The fluid-solid coupling problem is solved with a whole field solution method (i.e., flow profile in channels and temperature distribution in the system being simulated simultaneously).

RESULTS AND CONCLUSION

Simulation indicates that a cooling rate >10⁴ C/min is easily achievable using the microchannel method with the high flow rate for a board range of sample sizes. Channel size and material used have significant impact on cooling performance. Computational flow dynamics is useful for optimizing the design and operation of the microchannel system.

Diversity and antimicrobial activity of endophytic fungi isolated from Cephalotaxus hainanensis Li, a well-known medicinal plant in China

About 1051 endophytic fungi were isolated from leaves, branches, barks and stems of Cephalotaxus hainanensis Li from four sites in Hainan, China. The fungi were identified as 21 genera by morphology and ITS sequences. One dominant species was Phomopsis quercella in Hainan Tropical Botanical Garden and Bawangling Nature Reserve, with relative frequency of 42·06 and 34·88% respectively. Another dominant species was Colletotrichum boninense in Wuzhishan and Jianfengling Nature Reserves, with relative frequency of 36·84 and 46·97% respectively. Among the selected 21 endophytic fungi, 17 strains (80·95%) had activity against at least one pathogenic bacteria, and 14 strains (66·67%) exhibited activity against at least one fungal pathogens. Neonectria macroconidialis showed strong inhibition against Staphylococcus aureus (inhibition zone being 20 mm), Bacillus subtilis (14 mm) and Streptococcus agalactiae (28 mm). Xylaria sp. showed strong inhibition against Escherichia coli (20 mm), Rhizoctonia solani (20 mm) and Sclerotinia sclerotiorum (17 mm). Verticillium bulbillosum showed great activity against Strep. agalactiae (32 mm) and Fusarium oxysporum (22 mm). These endophytic fungi showed potentials in medicine development.

SIGNIFICANCE AND IMPACT OF THE STUDY

Endophytic fungi from medicinal plants are an important source of novel and viable drugs. Cephalotaxus hainanensis Li is well known for leukaemia treatment and its endophytic fungi were isolated to investigate the diversity and antimicrobial activity. It was found that Ce. hainanensis Li had rich endophytic fungi, and some fungi showed strong antimicrobial activity against certain pathogens. These fungi can be used in medicine development.

Molecular cloning, sequence identification, and gene expression analysis of bovine ADCY2 gene

Adenylyl cyclase 2 (ADCY2), a class B member of adenylyl cyclases, is important in accelerating phosphor-acidification as well as glycogen synthesis and breakdown. Given its distinct role in flesh tenderization after butchering, we cloned and sequenced the ADCY2 gene from Yanbian cattle and assessed its expression in bovine tissues. A 2947 bp nucleotide sequence representing the full-length cDNA of bovine ADCY2 gene was obtained by 5' and 3' remote analysis computations for gene expression. Analyses of the putative protein sequence showed that ADCY2 had high homology among species, except with the non-mammal Oreochromis niloticus. Gene structural domain analyses in humans and rats indicated that the ADCY2 protein had no flaw; only the transmembrane domain was reduced and the CYCc structure domain was shortened. Assessment of ADCY2 expression in bovine tissues by real-time PCR showed that the highest expression was in the testes, followed by the longissimus dorsi, tensor fasciae latae, and latissimus dorsi. These data will serve as a foundation for further insight into the cattle ADCY2 gene.

A novel β-glucosidase with lipolytic activity from a soil metagenome

Moonlighting proteins have two different functions within a single polypeptide chain. Exploring moonlighting enzymes from the environment using the metagenomic approach is interesting. In the present study, a novel β-glucosidase gene, designated as bgl1D, with lipolytic activity (renamed Lip1C) was cloned through function-based screening of a metagenomic library from uncultured soil microorganisms. The deduced amino acid sequence comparison and phylogenetic analysis also indicated that Lip1C and other putative lipases are closely related. Biochemical characterization demonstrated that the maximum activity of the recombinant Lip1C protein occurs at pH 8.0 and 30°C using 4-nitrophenyl butyrate as substrate. The putative lipase had an apparent K(m) value of 0.88 mmol/L, a k(cat) value of 212/min, and a k(cat)/K(m) value of 241 L/mmol/min. Lip1C exhibited habitat-specific characteristics with 5 mmol/L AlCl(3), CuCl(2), and LiCl. The characterization of the biochemical properties of Lip1C enhances our understanding of this novel moonlighting enzyme isolated from a soil metagenome.

Characterization of a novel serine protease inhibitor gene from a marine metagenome

A novel serine protease inhibitor (serpin) gene designated as Spi1C was cloned via the sequenced-based screening of a metagenomic library from uncultured marine microorganisms. The gene had an open reading frame of 642 base pairs, and encoded a 214-amino acid polypeptide with a predicted molecular mass of about 28.7 kDa. The deduced amino acid sequence comparison and phylogenetic analysis indicated that Spi1C and some partial proteinase inhibitor I4 serpins were closely related. Functional characterization demonstrated that the recombinant Spi1C protein could inhibit a series of serine proteases. The Spi1C protein exhibited inhibitory activity against α-chymotrypsin and trypsin with K_i values of around 1.79 × 10⁻⁸ and 1.52 × 10⁻⁸ M, respectively. No inhibition activity was exhibited against elastase. Using H-d-Phe-Pip-Arg-pNA as the chromogenic substrate, the optimum pH and temperature of the inhibition activity against trypsin were 7.0–8.0 and 25 °C, respectively. The identification of a novel serpin gene underscores the potential of marine metagenome screening for novel biomolecules.

[Cloning and diversity analysis of microorganism genes from alkalescence soil]

The metagenomic DNAs were extracted and purified from alkalescence environmental samples directly. On the basis of the metagenomic DNA, the alkaline soil 16S rDNA library composed of 5,562 positive clones was constructed. The phylogenic tree indicated that the bacteria from the alkaline soils were bio-diversity. The metagenomic DNA library named AL01 was constructed by inserting restriction fragments of the purified DNAs into plasmids pGEM-3Zf(+) vector. This library contained 23,650 positive clones and the average foreign DNA fragments were about 3.2 kb. The length of the library covered 75.68 Mb. The efficiency of the metagenomic library was approximately 6,000 clones from 1g dry soil samples. After screening AL01 DNA library with the screening tactics of enzymes, we confirmed that a positive clone, designated pGXAA2011, contained an alkaline protease gene AP01. Enzymatic analysis proved that its reaction optimum pH was 9.5 and the optimum temperature was 40 degrees C. Furthermore, a clone, designated pGXAG142 was screened from metagenomic DNA library, which expresses beta-glucosidase. DNA sequence indicated that the potential ORF of pGXAG142, which was named unglu01, there was no DNA or amino acids identity with the known beta-glucosidase genes in the Genbank. The integrated ORF was cloned into pETBlue-2 vector and was then transformed into Tuner(DE3)pLacI. The recombinant expression clone could express beta-glucosidase on the screening plate clearly and the analysis of SDS-PAGE indicated that the target protein was about 29 kDa.

[Inferring genotype of DNA molecular marker by Bayesian theorem]

Bayesian theorem is applied to infer DNA molecular marker genotype (DNA chain type) from its phenotype (electrophoresis band type). The results indicate that large difference often presents in the genotype probability of a molecular marker with incomplete genetic information when it is obtained from the assumption of independence among markers as compared with that inferred from the genotypes of the flanking markers with the complete genetic information and the recombination fractions among them based on the Bayesian theorem. Therefore, before utilizing the marker information, such as in mapping quantitative trait loci (QTL), marker assisted selection (MAS) etc., Bayes' probability of the genotype for all markers with incomplete genetic information must be calculated over the whole genome for every individual. This study provided detailed procedure for the calculation of the Bayes' probability of the unknown DNA genotype. Several extensions were also discussed for the application of the Bayesian theorem in genetics.

Molecular cloning of a novel importin alpha homologue from rice, by which constitutive photomorphogenic 1 (COP1) nuclear localization signal (NLS)-protein is preferentially nuclear imported

Nuclear import of proteins that contain classical nuclear localization signals (NLS) is initiated by importin alpha, a protein that recognizes and binds to the NLS in the cytoplasm. In this paper, we have cloned a cDNA for a novel importin alpha homologue from rice which is in addition to our previously isolated rice importin alpha1a and alpha2, and we have named it rice importin alpha1b. In vitro binding and nuclear import assays using recombinant importin alpha1b protein demonstrate that rice importin alpha1b functions as a component of the NLS-receptor in plant cells. Analysis of the transcript levels for all three rice importin alpha genes revealed that the genes were not only differentially expressed but that they also responded to dark-adaptation in green leaves. Furthermore, we also show that the COP1 protein bears a bipartite-type NLS and its nuclear import is mediated preferentially by the rice importin alpha1b. These data suggest that each of the different rice importin alpha proteins carry distinct groups of nuclear proteins, such that multiple isoforms of importin alpha contribute to the regulation of plant nuclear protein transport.

Interaction of pollen-specific actin-depolymerizing factor with actin

We have examined the interaction of recombinant lily pollen ADF, LlADF1, with actin and found that whilst it bound both G- and F-actin, it had a much smaller effect on the polymerization and depolymerization rate constants than the maize vegetative ADF, ZmADF3. An antiserum specific to pollen ADF, antipADF, was raised and used to localize pollen ADF in daffodil--a plant in which massive reorganizations of the actin cytoskeleton have been seen to occur as pollen enters and exits dormancy. We show, for the first time, an ADF decorating F-actin in cells that did not result from artificial increase in ADF concentration. In dehydrated pollen this ADF : actin array is replaced by actin : ADF rodlets and aggregates of actin, which presumably act as a storage form of actin during dormancy. In germinated pollen ADF has no specific localization, except when an adhesion is made at the tip where actin and ADF now co-localize. These activities of pollen ADF are discussed with reference to the activities of ZmADF3 and other members of the ADF/cofilin group of proteins.

A new class of microtubule-associated proteins in plants

In plants there are three microtubule arrays involved in cellular morphogenesis that have no equivalent in animal cells. In animals, microtubules are decorated by another class of proteins - the structural MAPS - which serve to stabilize microtubules and assist in their organization. The best-studied members of this class in plants are the MAP-65 proteins that can be purified together with plant microtubules after several cycles of polymerization and depolymerization. Here we identify three similar MAP-65 complementary DNAs representing a small gene family named NtMAP65-1, which encode a new set of proteins, collectively called NtMAP65-1. We show that NtMAP65-1 protein localizes to areas of overlapping microtubules, indicating that it may function in the behaviour of antiparallel microtubules in the mitotic spindle and the cytokinetic phragmoplast.

In vitro characterization of rice importin beta1: molecular interaction with nuclear transport factors and mediation of nuclear protein import

We recently isolated two cDNAs encoding importin 3 homologues (rice importin beta1 and beta2), the first such homologues identified in plants. To address the function of rice importin beta1 in the process of nuclear import of proteins, we carried out in vitro binding and nuclear import assays. Recombinant protein of rice importin beta1 assembled a complex (PTAC) with rice importin alpha1 and NLS protein, and also bound to the nuclear envelope of tobacco BY-2 cells. Ran-GTP, but not Ran-GDP, interacted with rice importin beta1 and dissociated the heterodimer formed between rice importin alpha1 and rice importin beta1. An in vitro nuclear import assay using digitonin-permeabilized HeLa cells revealed that rice importin beta1 can mediate nuclear envelope docking of NLS proteins and their subsequent translocation into the nucleus. These data strongly suggest that rice importin beta1 functions as a component of the NLS receptor in plant cells.

Functional characterization of a plant importin alpha homologue. Nuclear localization signal (NLS)-selective binding and mediation of nuclear import of nls proteins in vitro

Nuclear import of most nuclear proteins is initiated by recognition of the nuclear localization signal (NLS) by importin alpha. We recently isolated an importin alpha homologue from rice (rice importin alpha1) and demonstrated that transcription of the gene is down-regulated by light in rice leaves. To address the function of rice importin alpha1 in the process of nuclear import of proteins, we performed in vitro binding and nuclear import assays. The rice importin alpha1 showed specific binding to fusion proteins containing either monopartite or bipartite NLSs, but not to a fusion protein containing a Matalpha-2-type NLS, suggesting that there exists selective binding of rice importin alpha1 to different plant NLSs. The rice importin alpha1 is also capable of forming a complex with mouse importin beta and NLS protein in vitro. An in vitro nuclear import assay using permeabilized HeLa cells revealed that rice importin alpha1, in conjunction with other vertebrate transport factors, mediates the nuclear envelope docking of NLS proteins and their subsequent translocation into the nucleus. These data provide strong, direct evidence suggesting that rice importin alpha1 functions as a component of the NLS receptor in plant cells.

Isolation and characterization of two importin-beta genes from rice

The nuclear transport of proteins is mediated by the complex of importin-alpha and importin-beta. We isolated two cDNAs encoding importin-beta from rice. A rice importin-beta was demonstrated to interact with rice GST-importin-alpha fusion proteins. The presence of two importin-beta genes was shown for the first time among a variety of eukaryotes.

Ser6 in the maize actin-depolymerizing factor, ZmADF3, is phosphorylated by a calcium-stimulated protein kinase and is essential for the control of functional activity

Maize actin-depolymerizing factor, ZmADF, binds both G- and F-actin and enhances in vitro actin dynamics. Evidence from studies on vertebrate ADF/cofilin supports the view that this class of protein responds to intracellular and extracellular signals and causes actin reorganization. As a test to determine whether such signal-responsive pathways existed in plants, this study addressed the ability of maize ADF to be phosphorylated and the likely effects of such phosphorylation on its capacity to modulate actin dynamics. It is shown that maize ADF3 (ZmADF3) can be phosphorylated by a calcium-stimulated protein kinase present in a 40-70% ammonium sulphate fraction of a plant cell extract. Phosphorylation is shown to be on Ser6, which is only one of nine amino acids that are fully conserved among the ADF/cofilin proteins across distantly related species. In addition, an analogue of phosphorylated ZmADF3 created by mutating Ser6 to Asp6 (zmadf3-4) does not bind G- or F-actin and has little effect on the enhancement of actin dynamics. These results are discussed in context of the previously observed actin reorganization in root hair cells.

The maize actin-depolymerizing factor, ZmADF3, redistributes to the growing tip of elongating root hairs and can be induced to translocate into the nucleus with actin

The maize actin depolymerizing factor, ZmADF3, binds G- and F-actin, and increases in vitro actin dynamics. Polyclonal antibodies have been raised against ZmADF3 and these detect a single band of approximately 17 kDa in all maize tissues examined, with the exception of pollen. In the development of root hairs, the distribution of ZmADF3 is related to actin reorganization. In the early stages of hair development, ZmADF3 is distributed throughout the cytoplasm. As the hair emerges and the microfilament bundles redirect to the outgrowth there is a simultaneous redistribution of ZmADF3 which now concentrates at the tip of the emerging hair and remains in this position as elongation proceeds. These observations show that ZmADF3 localizes to a region where actin is being remodelled during tip growth. After cytochalasin D treatment which disrupts actin filaments, short rods of ZmADF3 and actin appear in the nucleus suggesting that ZmADF3 may function by guiding actin to sites of actin polymerization.

F-actin and G-actin binding are uncoupled by mutation of conserved tyrosine residues in maize actin depolymerizing factor (ZmADF)

Actin depolymerizing factors (ADF) are stimulus responsive actin cytoskeleton modulating proteins. They bind both monomeric actin (G-actin) and filamentous actin (F-actin) and, under certain conditions, F-actin binding is followed by filament severing. In this paper, using mutant maize ADF3 proteins, we demonstrate that the maize ADF3 binding of F-actin can be spatially distinguished from that of G-actin. One mutant, zmadf3-1, in which Tyr-103 and Ala-104 (equivalent to destrin Tyr-117 and Ala-118) have been replaced by phenylalanine and glycine, respectively, binds more weakly to both G-actin and F-actin compared with maize ADF3. A second mutant, zmadf3-2, in which both Tyr-67 and Tyr-70 are replaced by phenylalanine, shows an affinity for G-actin similar to maize ADF3, but F-actin binding is abolished. The two tyrosines, Tyr-67 and Tyr-70, are in the equivalent position to Tyr-82 and Tyr-85 of destrin, respectively. Using the tertiary structure of destrin, yeast cofilin, and Acanthamoeba actophorin, we discuss the implications of removing the aromatic hydroxyls of Tyr-82 and Tyr-85 (i.e., the effect of substituting phenylalanine for tyrosine) and conclude that Tyr-82 plays a critical role in stabilizing the tertiary structure that is essential for F-actin binding. We propose that this tertiary structure is maintained as a result of a hydrogen bond between the hydroxyl of Tyr-82 and the carbonyl of Tyr-117, which is located in the long alpha-helix; amino acid components of this helix (Leu-111 to Phe-128) have been implicated in G-actin and F-actin binding. The structures of human destrin and yeast cofilin indicate a hydrogen distance of 2.61 and 2.77 A, respectively, with corresponding bond angles of 99.5 degrees and 113 degrees, close to the optimum for a strong hydrogen bond.

Pollen specific expression of maize genes encoding actin depolymerizing factor-like proteins

In pollen development, a dramatic reorganization of the actin cytoskeleton takes place during the passage of the pollen grain into dormancy and on activation of pollen tube growth. A role for actin-binding proteins is implicated and we report here the identification of a small gene family in maize that encodes actin depolymerizing factor (ADF)-like proteins. The ADF group of proteins are believed to control actin polymerization and depolymerization in response to both intracellular and extracellular signals. Two of the maize genes ZmABP1 and ZmABP2 are expressed specifically in pollen and germinating pollen suggesting that the protein products may be involved in pollen actin reorganization. A third gene, ZmABP3, encodes a protein only 56% and 58% identical to ZmABP1 and ZmABP2, respectively, and its expression is suppressed in pollen and germinated pollen. The fundamental biochemical characteristics of the ZmABP proteins has been elucidated using bacterially expressed ZmABP3 protein. This has the ability to bind monomeric actin (G-actin) and filamentous actin (F-actin). Moreover, it decreases the viscosity of polymerized actin solutions consistent with an ability to depolymerize filaments. These biochemical characteristics, taken together with the sequence comparisons, support the inclusion of the ZmABP proteins in the ADF group.

Mini-dose intrathecal morphine for post-cesarean section analgesia

Dose-response relationship of mini-dose intrathecal morphine (0.025-0.125 mg) for analgesia after Cesarean section was studied. Sixty-three patients were randomly divided into six groups by the following intrathecal morphine injection: group 1 (0 mg), group 2 (0.025 mg), group 3 (0.05 mg), group 4 (0.075 mg), group 5 (0.1 mg), and group 6 (0.125 mg). The selected dose of morphine mixed with 2 ml 0.5% hyperbaric bupivacaine (10 mg) was administered intrathecally to induce spinal anesthesia. The mean analgesia duration in each group was 3.6 +/- 2.0, 10.6 +/- 7.1, 17.3 +/- 13.8, 25.6 +/- 7.5, 33.9 +/- 10.1, and 39.5 +/- 11.9 h respectively (mean +/- SD). In morphine groups, duration of analgesia was significantly longer (p less than 0.05) than control group (0 mg), and the first 24 h pain scores were also lower (p less than 0.01). Furthermore, a significant linear dose-response relationship between analgesic duration and the dose of intrathecal morphine was revealed (y = 3.28 + 295.5x, r2 = 0.64, p less than 0.05). Among morphine groups, analgesic quality was significantly better in patients in groups 4-6 than those in group 2 and 3 (p less than 0.05), so as in the proportion of effective analgesia in the first 24 h (p less than 0.01). Neonatal condition was not adversely affected by such mini-dose of intrathecal morphine. The most common maternal adverse effect observed was pruritus, and its incidence was significantly greater in groups 3-6 than in the control group (p less than 0.05). However, no significant difference was observed among all morphine groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Epirubicin and cytosine arabinoside for the induction therapy of childhood acute nonlymphocytic leukemia

Epirubicin, a new anthracycline, was used in combination with cytosine arabinoside for the induction therapy of de novo acute nonlymphocytic leukemia in childhood. The treatment consisted of epirubicin 20 mg/m2/day for 3 days and cytosine arabinoside 100 mg/m2/day for 7 days. The treatment could be repeated every 3 weeks. Remission induction rate was 80% (20/25). Moreover, in 13 patients, the remissions were obtained after a single course. In general, the side effects of epirubicin and cytosine arabinoside were tolerable. However, the main causes of all the three deaths were infections. Our study suggests that epirubicin is acceptable and effective for the induction therapy for de novo acute nonlymphocytic leukemia in childhood.

Comparison of lower concentrations of lidocaine to suppress bucking before extubation during recovery of general anesthesia

Thirty females, aged 25-50 years old, scheduled for abdominal total hysterectomy were randomly divided to two groups. For patients in group I, 2 mL 1% lidocaine solution was injected through the catheter on the tube to desensitize the trachea while surgeon started to close the peritoneum. In group II, 2 mL 2% lidocaine was used. The peak cuff pressures generated in the awakening group I patients were 49.0 +/- 2.5 cmH2 O (mean +/- SD) which shows greater than that in group II (27.9 +/- 7.2 cmH2 O), p less than 0.01. Bucking before awakening was also evaluated clinically. One hundred % (15/15) in group I patients bucked compared with 13.3% (2/15) in group II patients (p less than 0.01). Gag reflex was preserved in all patients and none suffered from aspiration postoperatively. Intratracheal administration of two mL 2% lidocaine through the catheter of modified endotracheal tube showed significant effect for suppressing bucking during recovery of general anesthesia.

The application of pulse oximeter for supraclavicular brachial block

The subclavian artery is the most important landmark of the supraclavicular brachial block. However, it is difficult to locate the artery by palpation in the patients with poor landmark. The present study was aimed to compare two localizing methods of the subclavian artery by a pulse oximeter or by palpation. One hundred patients were divided into three groups. Group A (Slim Group): 6 patients, Group B (Normal Weight Group): 75 and Group C (Obese Group): 19. All patients received both methods to locate the subclavian artery. The first method was by palpating the pulsation of the subclavian artery. The second was by observing the wave depression of the pulse oximeter while pressing supraclavicular area. It was found that the detection rate of the first method was 83.3% in Group A, 52.0% in Group B, 26.3% in Group C and 49.0% in overall patients. However, the detection rate of the second method was 100% in each group. It shows a significant difference between the two methods in Group B, Group C and all patients (P less than 0.001), but no difference in Group A (P = 0.68). There were 13 patients among the 100 patients undergoing surgery of the upper extremity. Seven of them whose pulsation was not clearly palpated but could be located exactly by pulse oximeter. Supraclavicular brachial block was still completed successfully in these 13 patients. No pneumothorax was found. Utilizing pulse oximeter in supraclavicular block provides a high detection rate of the pulsation of the subclavian artery and improves the reliability of the block, especially in the patients with poor landmark.

[A study of insertional length of umbilical artery catheters in newborns]

To correlate the neonatal body measurements that best predict insertional length of the umbilical artery catheter (UAC), we performed this study with two separate parts. In part I, we collected 120 cases with indication for umbilical artery catheterization from Mackay Memorial Hospital during December 1986 to November 1987. They were randomly divided into 4 groups and in each group the internal catheter length of UAC was calculated with formula of: Gr. 1. 3 birth weight (BW) (Kg) + 9 (cm), Gr. 2. suprasternal notch to public symphysis length (SSL) (cm), Gr. 3. 1/3 total body length (TBL) (cm), Gr. 4. shoulder to umbilicus length (SUL) + 2 (cm). The accuracy was 90% in BW group, 90% in TBL group, 70% in SSL group and 70% in SUL group respectively, and there was no statistical difference between any two groups. However, BW and TBL formula were clinically more practical than the other two (SUL and SSL). In part II of our study, out of 120 cases we selected 63 appropriate for gestational age (AGA) cases with catheter tips placed between the 7th and 9th thoracic vertebra. Correlation coefficients (rs) between inserted length of UAC and each of the four parameter (BW, TBL, SSL, and SUL) were shown to have statistically significant correlation. There was no statistical difference among those correlation coefficients. Modified regression equations derived from BW, SSL, TBL and SUL were 1.7BW (kg) + 2 (cm). 2. SSL (cm). 3. 1/3 TBL (cm) + 0.5 (cm). 4. SUL (cm) + 1 (cm). Further study would be necessary for establishing a more widely adaptable equation.

Use of the multinomial Dirichlet model for analysis of subdivided genetic populations

The distribution found by compounding the multinomial distribution with the Dirichlet distribution has been suggested as a basis for the estimation of parameters in subdivided populations, in particular of the "correlation between genotypes" within subpopulations. It is shown that the estimators deriving from these procedures perform poorly when the data are generated by the classical Wright drift model of subdivided populations. This conclusion suggests that the compound distribution estimation approach does not provide a good estimation procedure for real populations which are reasonably described by the Wright model.

Pharmacology of radioiodinated hexadecenoic acid--a myocardial imaging agent

123I- and 131I-labeled hexadecenoic acid (IHDA, radiochemical purity over 92%, dissolved in 6% bovine serum albumin solution) was investigated in vivo. ICR mice were administered IHDA via the tail vein. Maximum myocardial uptake (27.3 +/- 5.1%) was reached about 0.5 min after the injection. The ratio of uptake in the heart to that in the lungs was 2.3, to that in liver 1.5 and to that in other organs 2.4 to 6.4. The dog myocardium was visualized distinctly within 3-5 min with a gamma camera after i.v. 131I-IHDA, and not interfered with by activities in the lungs, liver and other organs. The low blood levels at 20 min had little effect on the quality of the heart images.