Endovascular repair of acute vs. subacute uncomplicated type B aortic dissection: a systematic review and meta-analysis

Objective

This study aimed to conduct a meta-analysis evaluating the optimal timing for endovascular repair of acute versus subacute uncomplicated Type B Aortic Dissection.

Method

PubMed, EMBASE, web of science and Cochrane Library was interrogated to identify Electronic bibliographic studies updated to January 2023 to collect studies compared the clinical outcomes of endovascular repair for Acute Versus Subacute Uncomplicated Type B Aortic Dissection. Data were aggregated as pooled odds ratios (OR) using the fixed or random effects models according to the significance of heterogeneity, Pooled odds ratios (OR) were calculated by RevMan 5.3 and applied with fixed or random-effect models.

Result

A comprehensive literature search found 322 citations published and finally among them 6 studies containing 3,769 patients (acute group 2,642, subacute group 1,127) were included in review. There is an increased risk of 30-day complications (OR = 1.51,95%CI,1.26-1.81) 30-day mortality (OR = 2.39,95%CI, 1.55-3.67) and 1-year mortality (OR = 1.71,95%CI,1.27-2.30) for an acute uTBAD group compared to subacute ones. Similarly, reintervention was more likely in the acute group than in the subacute group (OR = 1.42,95%CI,1.05-1.91). However, no significant differences were found in long-term mortality.

Conclusion

This meta-analysis confirmed that there was no significant difference in the long-term prognosis between the acute and subacute phases in the timing of surgery. However, considering the high incidence of complications, high re-intervention rate and one-year mortality probably caused by high intima fragility in the acute phase, endovascular repair at subacute phase appears to favorably compare with acute strategy. But future studies with adequate patient numbers and longer-term follow-up are necessary to further verify the study conclusion.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021247609, identifier PROSPERO CRD42021247609.

Development of an indirect enzyme-linked immunosorbent assay for the detection of novel chicken orthoreovirus

A novel avian orthoreovirus (N-ARV) variant characterized with obvious arthritis and synovial inflammation, was isolated from Shandong, China in May 2016. It caused chicken poor growth and enormous economic losses to the poultry industry of China. However, there are few effective methods for detecting the antibody levels of N-ARV. In this study, a viral structural protein σC was expressed using the prokaryotic expression vector pET32a (+). The target protein was obtained by inducing for 6 hours at an IPTG concentration of 0.6mM. The optimal dilution of the coating antigen and serum antibody were determined to be 1000 fold and 10 fold respectively. A specificity test showed that there was no positive reactivity between N-ARV and other pathogens, and when the positive serum was diluted 100 times detection results were still checkable. The repeatability of this method was determined by the inter assay and intra assay tests with variability ranging from 4.85% to 7.93%. In conclusion, this indirect enzyme linked immunosorbent assay (ELISA) will be useful for large-scale serological surveys and monitoring antibody levels in N-ARV infection.

Safety, feasibility, and effect of an enhanced nutritional support pathway including extended preoperative and home enteral nutrition in patients undergoing enhanced recovery after esophagectomy: a pilot randomized clinical trial

The aims of this pilot study are to evaluate the feasibility, safety, and effectiveness of conducting an enhanced nutritional support pathway including extended preoperative nutritional support and one month home enteral nutrition (HEN) for patients who underwent enhanced recovery after esophagectomy. We implemented extended preoperative nutritional support and one month HEN after discharge for patients randomized into an enhanced nutrition group and implemented standard nutritional support for patients randomized into a conventional nutrition group. Except the nutritional support program, both group patients underwent the same standardized enhanced recovery after surgery programs of esophagectomy based on published guidelines. Patients were assessed at preoperative day, postoperative day 7 (POD7), and POD30 for perioperative outcomes and nutritional status. To facilitate the determination of an effect size for subsequent appropriately powered randomized clinical trials and assess the effectiveness, the primary outcome we chose was the weight change before and after esophagectomy. Other outcomes including body mass index (BMI), lean body mass (LBM), appendicular skeletal muscle mass index (ASMI), nutrition-related complications, and quality of life (QoL) were also analyzed. The intention-to-treat analysis of the 50 randomized patients showed that there was no significant difference in baseline characteristics. The weight (-2.03 ± 2.28 kg vs. -4.05 ± 3.13 kg, P = 0.012), BMI (-0.73 ± 0.79 kg/m2 vs. -1.48 ± 1.11 kg/m2, P = 0.008), and ASMI (-1.10 ± 0.37 kg/m2 vs. -1.60 ± 0.66 kg/m2, P = 0.010) loss of patients in the enhanced nutrition group were obviously decreased compared to the conventional nutrition group at POD30. In particular, LBM (48.90 ± 9.69 kg vs. 41.96 ± 9.37 kg, p = 0.031) and ASMI (7.56 ± 1.07 kg/m2 vs. 6.50 ± 0.97 kg/m2, P = 0.003) in the enhanced nutrition group were significantly higher compared to the conventional nutrition group at POD30, despite no significant change between pre- and postoperation. In addition, European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 scores revealed that enhanced nutritional support improved the QoL of patients in physical function (75.13 ± 9.72 vs. 68.33 ± 7.68, P = 0.009) and fatigue symptom (42.27 ± 9.93 vs. 49.07 ± 11.33, P = 0.028) compared to conventional nutritional support. This pilot study demonstrated that an enhanced nutritional support pathway including extended preoperative nutritional support and HEN was feasible, safe, and might be beneficial to patients who underwent enhanced recovery after esophagectomy. An appropriately powered trial is warranted to confirm the efficacy of this approach.

Sex-related differences in response to zinc pyrithione shampoo vs. non-anti-dandruff shampoo

OBJECTIVE

Sex-related differences in skin properties may be expected to impact dandruff formation and treatment. A meta-analysis approach was undertaken to investigate potential differences between males and females in response to zinc pyrithione (ZnPT) treatment vs. non-anti-dandruff (AD) shampoo. A separate pooled statistical analysis of ceramide and total protein loss endpoints was also undertaken to assess potential sex-related differences in stratum corneum properties that might influence response to ZnPT vs. non-AD shampoo in subjects with dandruff.

METHODS

The meta-analysis approach included data from 17 half-head, double-blind, randomized studies (N = 2088) undertaken in Asia to assess the effectiveness of 1% ZnPT shampoo and/or non-AD shampoo in reducing dandruff severity, as assessed by Total Weighted Head Score Adherent Flake (TWHS-AF) methodology. Treatment duration was 4 weeks, with TWHS-AF measured at weekly intervals. Data from an additional three studies (N = 143) conducted in Asia were included in the pooled analysis of ceramide levels and protein loss from scalp skin of subjects with dandruff.

RESULTS

Response to 1% ZnPT vs. non-AD shampoo was greater in males than in females at all time points; after 4 weeks, the between-treatment difference in TWHS-AF was -17.5 (95% confidence interval [CI] -19.5, -15.5) in males and -11.1 (-13.2, -8.9) in females. Sex-related differences were observed between males and females in response to both 1% ZnPT and non-AD shampoos. Males had a stronger response than females to treatment with 1% ZnPT shampoo, while dandruff decreased to a greater extent in females than in males when using non-AD shampoo. Statistically significant sex-related differences in ceramide levels and total protein loss were observed (both P < 0.01). Ceramide levels were 0.76 times lower (95% CI 0.60, 0.97) in males than in females, while total protein loss was 1.4 times greater (95% CI 1.1, 1.9) in males than in females.

CONCLUSION

Males show a greater response than females to 1% ZnPT shampoo, while females show a greater response than males to non-AD shampoo. These findings may in part be explained by the sex-related differences observed in stratum corneum properties, which may make males more prone to dandruff than females.

Epidemiological investigation of H9 avian influenza virus, Newcastle disease virus, Tembusu virus, goose parvovirus and goose circovirus infection of geese in China

To deepen the knowledge about epidemic prevalence in the goose breeding field, a triplex PCR assay was established, and 478 samples were collected from scaled goose farms in 11 provinces in China. The results of this epidemiological investigation showed that incidence rates of H9 avian influenza and goose circovirus were the highest among five infectious diseases that were evaluated. In addition, the triplex PCR assay established remarkable sensitivity, rapidity and versatility compared to other diagnostic methods. Dual infection comprised a large proportion of the co-infections in the field, of which the combinations of H9/Tembusu, H9/goose circovirus and goose circovirus/Tembusu co-infected cases were more common. Epidemics were more severe in winter and spring. Additionally, significant differences in the prevalence of these infectious diseases were observed in association with different age groups. In addition, phylogenetic analysis, determined by the neighbour-joining method, was carried out to investigate the evolution of these viruses during the study period. For the most part, virus strains isolated during the study were consistent with most goose-origin strains isolated from the Chinese mainland over the past few years. However, mutations were observed between isolated H9 avian influenza virus strains and sequences available from GenBank, which should draw much attention.

Dorsal open reduction with pedicle screw rod internal fixation for lower cervical spine dislocation: A retrospective analysis of 12 cases

BACKGROUND

Lower cervical spine dislocation remains a surgical challenge.

METHODS

Twelve patients with lower cervical dislocation due to articular process injury underwent dorsal open reduction and manual pedicle screw rod fixation. Patients with cervical spinal cord injury received simultaneous open door expansive laminoplasty. Neurological function was evaluated using ASIA Impairment Scale 12.

RESULTS

Median time from injury to operation was 10 days (range, 5 to 52 days). Anatomic reduction was achieved in all patients. In nine patients with cervical spinal cord injury, 55.5% (5/9) showed improvement in ASIA grade following surgery. Unilateral numbness of the superior radicular area in one patient resolved 2 weeks post-surgery and two cases (11.1%, 2/9) had postoperative leakage of the cerebrospinal fluid, which resolved in 11 days and 13 days, respectively.

CONCLUSION

Dorsal open reduction and manual pedicle screw rod fixation is safe and effective for lower cervical spine dislocation due to articular process injury.

Cloning and characterization of the UBC gene from lotus (Nelumbo nucifera)

Protein ubiquitination is extensively involved in the regulation of a considerable number of physiological processes in plant cells. E2 (ubiquitin-conjugating enzyme, UBC), one of the essential enzymes of eukaryotic ubiquitination, catalyzes protein ubiquitination together with E1 and E3. In this study, we cloned four full-length cDNA NnUBCs of Nelumbo nucifera. With the same coding sequence length of 459 bp and coding 153 amino acids, these four genes are highly homologous with the AtUBC1 and AtUBC2 of Arabidopsis thaliana. Quantitative fluorescence polymerase chain reaction showed that these four genes exhibited different expression patterns in different tissues of N. nucifera. Overall, the expression of NnUBC3 was the highest in all plant tissues. Tests of different stress treatments showed that NnUBC3 plays an important role in response to heat, salt, and drought stresses in N. nucifera. Moreover, transgenic Arabidopsis plants (Atubc1-1Atubc2-1 mutant) expressing NnUBC3 presented a wild-type phenotype, indicating that NnUBC3 performs the same function as AtUBC1 and AtUBC2.

Evaluation of the biological differences of canine and human factor VIII in gene delivery: implications in human hemophilia treatment

The canine is the most important large animal model for testing novel hemophilia A (HA) treatment. It is often necessary to use canine factor VIII (cFIII) gene or protein for the evaluation of HA treatment in the canine model. However, different biological properties between cFVIII and human FVIII (hFVIII) indicated that the development of novel HA treatment may require careful characterization of non-human FVIII. To investigate whether the data obtained using cFVIII can translate to HA treatment in human, we analyzed the differential biological properties of canine heavy chain (cHC) and light chain (cLC) by comparing with human heavy chain (hHC) and light chain (hLC). The secretion of cHC was 5-30-fold higher than hHC, with or without light chains (LCs). cHC+hLC group exhibited ~18-fold increase in coagulation activity compared with hHC+hLC delivery by recombinant adeno-associated viral vectors. Unlike hHC, the secretion of cHC was independent of LCs. cLC improves the specific activity of FVIII by two- to threefold compared with hLC. Moreover, the cLC, but not cHC, contributes to the higher stability of cFVIII. Our results suggested that the cFVIII expression results in the canine model should be interpreted with caution as the cHC secreted more efficiently than hHC and cLC exhibited a more active and stable phenotype than hLC.

Evidence for Vertical Transmission of Novel Duck-Origin Goose Parvovirus-Related Parvovirus

In 2015, novel duck-origin goose parvovirus-related parvovirus (N-GPV) infection progressively appeared in commercial Cherry Valley duck flocks in North China. Diseased ducks were observed to have beak atrophy and dwarfism syndrome (BADS). A previous study showed that a high seropositive rate for N-GPV indicated a latent infection in most breeder duck flocks. To investigate this possibility in hatching eggs collected from N-GPV-infected breeder ducks, 120 eggs were collected at various stages of embryonic development for viral DNA detection and an N-GPV-specific antibody test. N-GPV DNA was present in nine hatching eggs, eleven duck embryo and eight newly hatched ducklings. Of the newly hatched ducklings, 58.33% (21/36) were seropositive. Further, two isolates were obtained from a 12-day-old duck embryo and a newly hatched duckling. N-GPV infection did not reduce the fertilization rate and hatchability. These results indicate possible vertical transmission of N-GPV and suggest that it may be transmitted from breeder ducks to ducklings in ovo.

Identification and characterization of chalcone synthase cDNAs (NnCHS) from Nelumbo nucifera

Chalcone synthase (CHS) catalyzes the first committed step in flavonoids biosynthetic pathway. In this study, six full-length cDNAs (NnCHS) encoding CHS from Nelumbo nucifera were successfully isolated, using rapid amplification cDNA end (RACE) assay. The obtained cDNAs were 1426 bp in size, containing a 1167 bp open reading frame coding 389 amino acids. Exons-intron architecture of NnCHS gene was illustrated, consisting two exons inserted by a 426 bp intron. The putative NnCHS possessed all the conserved active sites for CHS function as well as the family signature. Phylogenetic analysis revealed that NnCHS shared high homology with CHS from high plants, and the homology-based structural modeling showed that NnCHS had the typical structure of CHS. Moreover, Real-time PCR assays demonstrated that NnCHS mRNAs were expressed in various tissues of N. nucifera, with the highest expression in red flower and lowest level in the leaves. Moreover, patterns of NnCHS expression illustrated short-time wounding or low temperature significantly induced the up-regulation of NnCHS mRNA.

Development and characterization of genic-SSR markers from different Asia lotus (Nelumbo nucifera) types by RNA-seq

Nelumbo nucifera is an important economic vegetable and traditional medicine, but available genetic resources remain limited. Next generation sequencing has proven to be a rapid and effective means of identifying genic simple sequence repeat (genic-SSR) markers. This study developed genic-SSRs for N. nucifera using Illumina sequencing technology to assess diversity across cultivated and wild lotus. A total of 105,834 uni-contigs were produced with an average read length of 722 bp. Exactly 11,178 genic-SSR loci were identified in 9523 uni-contigs. Di-nucleotide (64.5%) was the most abundant SSR, followed by tri-nucleotide (23%), tetra-nucleotide (8.9%), penta-nucleotide (2.5%), and hexa-nucleotide (1%) repeat types. The most common di- and tri-nucleotide repeat motifs were AG/CT (51%) and AAG/CTT (8%), respectively. Based on these SSRs sequences, 6568 primer pairs were designed, of which 72 primers were randomly selected for synthesis and validation, and 38 in-silico polymorphic primers were obtained using in-house perl scripts. A total of 110 primers were screened in the lotus samples and the results showed that 101 primers yielded amplification products, of which 80 were polymorphs. The number of alleles ranged from 2 to 17 and the PIC (polymorphism information content) ranged from 0.19 to 0.87 with a mean value of 0.55. An Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram based on Jaccard's similarity coefficients showed that the correlation between geographical source and genotype was low. This study describes the distribution of genic-SSRs in the expressed portion of the lotus genome. These genic-SSRs have an important role to play in molecular mapping, diversity analysis, and marker-assisted selection strategies in Nelumbo.

Leaf transcriptome analysis and development of SSR markers in water chestnut (Eleocharis dulcis)

Water chestnut (Eleocharis dulcis) is an important aquatic crop in China; however, transcriptomic and genomic data in public databases are limited. To identify genes and development molecular markers, high-throughput transcriptome sequencing was applied to generate transcript sequences from water chestnut leaf. More than 24 million reads were obtained, trimmed, and assembled into 40,796 contigs with an average length of 616.6 bp. Sequence similarity analyses against 4 public databases (NR, GO, KEGG, KOG) revealed 17,628 contigs that could be annotated with gene descriptions, conserved protein domains, or gene ontology terms. Among the important metabolic pathways, 27 genes were related to starch synthesis and 13 genes were in the steroid synthetic pathway. In addition, 2570 cDNA simple sequence repeats were identified as potential molecular markers in our contigs. One hundred pairs of polymerase chain reaction primers were designed and used for validation of the amplification. The results revealed that 87 primer pairs were successfully amplified in initial screening tests. Overall, this transcriptome dataset and these markers can serve as a platform for further gene expression studies, functional genomic studies, and marker-assisted selection in E. dulcis.

Recombinant human kallistatin inhibits angiogenesis by blocking VEGF signaling pathway

Kallistatin has been recognized as an endogenous angiogenic inhibitor. However, the underlying molecular mechanism remains poorly understood. Taking it into account that vascular endothelial growth factor (VEGF) has been implicated in all aspects of normal and pathological vasculogenesis and angiogenesis. In this study, we investigated whether VEGF signaling pathway was impacted by the anti-angiogenic effect of recombinant human kallistatin (rhKal). We found that the rhKal inhibited proliferation as well as induced apoptosis of cultured human umbilical vein endothelial cells (HUVECs) in both concentration- and time-dependent manners. The rhKal also suppressed the VEGF-induced migration and tube formation of HUVECs. Furthermore, our data revealed that the rhKal suppressed the VEGF165-stimulated tyrosine phosphorylation of VEGFR-2 as well as its downstream signal molecular activation. The inhibition of receptor phosphorylation was correlated with a decrease in VEGF-triggered phosphorylation of angiogenesis signal molecules AKT and ERK, but not stress-related JNK. Taken together, these findings added the knowledge for us to understand the anti-angiogenic mechanism of kallistatin, which suggested that the rhKal could be worth as a candidate compound for further development for the purpose of anti-angiogenic therapies.

Isolation and genetic characterization of a tembusu virus strain isolated from mosquitoes in Shandong, China

Tembusu virus (TMUV) is a flavivirus, presumed to be a mosquito-borne flavivirus of the Ntaya virus subgroup. To date, however, there have been no reports indicating that mosquitoes are involved in the spread of TMUV. In this study, we report the first isolation of TMUV from Culex mosquitoes. We describe the isolation and characterization of a field strain of TMUV from mosquitoes collected in Shandong Province, China. The virus isolate, named TMUV-SDMS, grows well in mosquito cell line C6/36, in Vero and duck embryo fibroblast (DEF) cell lines, and causes significant cytopathic effects in these cell cultures. The TMUV-SDMS genome is a single-stranded RNA, 10 989 nt in length, consisting of a single open reading frame encoding a polyprotein of 3410 amino acids, with 5' and 3' untranslated regions of 142 and 617 nt, respectively. Phylogenetic analysis of the E and NS5 genes revealed that the TMUV-SDMS is closely related to the TMUV YY5 and BYD strains which cause severe egg-drop in ducks. The 3'NTR of TMUV-SDMS contains two pairs of tandem repeat CS and one non-duplicate CS, which have sequence similarities to the same repeats in the YY5 and BYD strains. Our findings indicate that mosquitoes carrying the TMUV may play an important role in the spread of this virus and in disease outbreak.

Tembusu virus in human, China

SUMMARY

Tembusu virus (TMUV) infection in ducks, geese and house sparrows was reported in China. To confirm the emergence of TMUV in humans, we investigated TMUV as a possible infection in duck industry workers in Shandong, China. Of 132 serum samples tested, 95 (71.9%) had TMUV antibodies. In oral swabs detection, 63 (47.7%) samples were positive for TMUV RNA. Nucleotide sequences of 277 bp coding the partial NS3 protein showed more than 99.5% identity with other duck TMUV strains, which can cause severe egg drop in ducks. These findings contribute to the realization that TMUV may be overlooked as a zoonotic transmission in China.

Isolation and characterization of microsatellite loci for the herbaceous tuber crop, Amorphophallus konjac (Araceae)

Amorphophallus konjac is an herbaceous tuber crop with tremendous potential for commercial development. We report the development of microsatellite primers for this important crop species. Thirteen polymorphic microsatellite markers were developed and tested in two populations of A. konjac from the Wuling Mountain Region (WL population) and the Yunnan Province (YN population) in China. The number of alleles per locus ranged from 1 to 7; the observed and expected heterozygosities ranged from 0 to 1 and from 0 to 0.844, respectively, in the two populations. These microsatellite markers will facilitate further studies in population genetics and utilization of A. konjac.

Increased Expression of MicroRNA-221 in gastric cancer and its clinical significance

OBJECTIVE

MicroRNA-221 (miR-221), which is located on chromosome X, is an oncogenic microRNA that is involved in several human malignancies. This study aimed to characterize the role of miR-221 in the initiation and malignant progression of gastric cancer.

METHODS

The level of miR-221 expression in 92 pairs of primary gastric tumour tissue and adjacent nontumour tissue was quantified by real-time reverse transcription-polymerase chain reaction. The relationship between the miR-221 level and clinicopathological features was explored.

RESULTS

MiR-221 was up-regulated in 88% (81/92) of gastric cancer tissue samples compared with their paired adjacent nontumour tissue samples. High expression of miR-221 showed a significant correlation with advanced tumour-node-metastasis stage, local invasion and lymphatic metastasis. Univariate and multivariate Cox proportional hazard regression analyses revealed that miR-221 overexpression was an unfavourable prognostic factor for overall survival in patients with gastric cancer.

CONCLUSIONS

These findings suggest that miR-221 is a novel prognostic indicator in gastric cancer and may be a potential target for diagnosis and gene therapy.

Characterization of a Tembusu virus isolated from naturally infected house sparrows (Passer domesticus) in Northern China

The house sparrow (Passer domesticus) is one of the most widely distributed wild birds in China. Tembusu virus (TMUV) strain, TMUV-SDHS, was isolated from house sparrows living around the poultry farms in Shandong Province, Northern China. Genetic analysis of E and NS5 genes showed that it had a close relationship with that of the YY5 strain, which can cause severe egg drop in ducks. Pathogenicity studies showed that the virus is highly virulent when experimentally inoculated into the ducks. These findings show that house sparrows carrying the Tembusu virus may play an important role in transmitting the virus among other species.

Analysis of the complete genome of Tembusu virus, a flavivirus isolated from ducks in China

During investigations into the outbreak of duck viral infection in 2010 in China, with a severe drop in egg production, a flavivirus was isolated from the affected ducks. It was characterized as a Tembusu virus (TMUV). In this study, we obtained a complete genome sequence of Tembusu virus using RT-PCR and RACE techniques. TMUV genome is a singled-stranded RNA, with 10,990 nucleotides in length, and contains a single open reading frame (3410 amino acids) encoding 11 viral proteins with 5'and 3'non-translated regions (NTRs) of 142 and 618 nt, respectively. We characterized the open reading frame (ORF) with respect to gene sizes, cleavage sites and potential glycosylation sites. The different genomic regions of the virus were also compared with those of six other flaviviruses including Japanese encephalitis virus, West Nile virus (WNV), dengue-2 virus, yellow fever virus, tick-borne encephalitis virus (TBEV) and Bagaza virus. TMUV demonstrated the highest similarity to Bagaza virus. The result of entire ORF scanning shows that TMUV was close to Bagaza viruses in genetic relatedness. These data demonstrate that TMUV is a unique virus among the mosquito-borne flaviviruses and also provide a useful reference for a critically important study to determine why TMUV is a serious pathogen for ducks.

On the mean and variance of the writhe of random polygons

We here address two problems concerning the writhe of random polygons. First, we study the behavior of the mean writhe as a function length. Second, we study the variance of the writhe. Suppose that we are dealing with a set of random polygons with the same length and knot type, which could be the model of some circular DNA with the same topological property. In general, a simple way of detecting chirality of this knot type is to compute the mean writhe of the polygons; if the mean writhe is non-zero then the knot is chiral. How accurate is this method? For example, if for a specific knot type K the mean writhe decreased to zero as the length of the polygons increased, then this method would be limited in the case of long polygons. Furthermore, we conjecture that the sign of the mean writhe is a topological invariant of chiral knots. This sign appears to be the same as that of an "ideal" conformation of the knot. We provide numerical evidence to support these claims, and we propose a new nomenclature of knots based on the sign of their expected writhes. This nomenclature can be of particular interest to applied scientists. The second part of our study focuses on the variance of the writhe, a problem that has not received much attention in the past. In this case, we focused on the equilateral random polygons. We give numerical as well as analytical evidence to show that the variance of the writhe of equilateral random polygons (of length n) behaves as a linear function of the length of the equilateral random polygon.

Comparative analysis of five varieties in Perilla frutescens (L.) Britton by 45S rDNA FISH and 5S rDNA sequences

In this study, the relationships of five varieties in Perilla frutescens (L.) Britton were analyzed. All the varieties showed the same chromosome number 2n = 40, and the banding patterns of PI-DAPI staining and the FISH results of 45S rDNA probe were on the same site of the chromosome pair. The 5S rRNA gene spacers were ranged from 413 bp in P. frutescens var. purpurascens and 408 bp in var. frutescens. The varieties analyzed here were clustered into two clades according to the phylogenetic analysis. The sequence identity of 96% between var. auriculato-dentata and var. arguta suggested they could be considered the same variety.

DNA Knotting in Spooling Like Conformations in Bacteriophages

A number of idealized models have been proposed to explain the long range organization of the DNA in bacteriophages. However, none of these models can account for the distributions of complex knots found when examining DNA extracted from bacteriophage P4 capsids. Furthermore, these models do not consider possible chirality biases in the arrangement of the DNA molecule inside the capsid. In this paper, we address these two issues by proposing a randomized version of one of the most popular models: the coaxially spooled model. We present analytical and numerical results for the properties of the random polygons (knots) generated using this model. We show that such model can easily generate complex knotted conformations and although it accounts for some chirality of the organization of the DNA molecules inside bacteriophage capsids does not fully explain the experimental data.

Using pseudo amino acid composition to predict transmembrane regions in protein: cellular automata and Lempel-Ziv complexity

Transmembrane (TM) proteins represent about 20-30% of the protein sequences in higher eukaryotes, playing important roles across a range of cellular functions. Moreover, knowledge about topology of these proteins often provides crucial hints toward their function. Due to the difficulties in experimental structure determinations of TM protein, theoretical prediction methods are highly preferred in identifying the topology of newly found ones according to their primary sequences, useful in both basic research and drug discovery. In this paper, based on the concept of pseudo amino acid composition (PseAA) that can incorporate sequence-order information of a protein sequence so as to remarkably enhance the power of discrete models (Chou, K. C., Proteins: Structure, Function, and Genetics, 2001, 43: 246-255), cellular automata and Lempel-Ziv complexity are introduced to predict the TM regions of integral membrane proteins including both alpha-helical and beta-barrel membrane proteins, validated by jackknife test. The result thus obtained is quite promising, which indicates that the current approach might be a quite potential high throughput tool in the post-genomic era. The source code and dataset are available for academic users at liml@scu.edu.cn.

Directional tunings independent of orientation in the primary visual cortex of the cat

A family of moving 'random-line' patterns was developed and used to study the directional tuning of 91 single units in cat primary visual cortex (V1). The results suggest that, in addition to the well-known orientation-dependent mechanism, there is also some kind of orientation-independent mechanism underlying the direction selectivity. The directional tuning of the neurons varies in accordance with the increase of orientation or non-orientation element in the stimulus.

[Ovarian follicular maldevelopment in infertile women]

OBJECTIVE

To study the manifestation and outcome of ovarian follicular maldevelopment (FM) in infertile women.

METHODS

Among 296 infertile women, 80 cases with FM were taken as study group and 20 with normal ovulation as control. Serial B-ultrasonography, cervical mucus scoring, serum estradiol (E2) assay and laparoscopy, endometrium histology were monitored in both groups.

RESULTS

The incidence of FM in infertile women was 27.0%, B-ultrasonography showed many small and obscure outlined follicles in the ovarian. The maximum and mean cervical mucus socres in FM group were < 9 and 7.3 +/- 1.8, significantly lower than those in control (> 10, 13.2 +/- 1.8) (P < 0.01). So were the midcycle serum E2 levels (300 +/- 100 pmol/L vs 900 +/- 400 pmol/L, P < 0.001). No stigma was found in two-third of FM patients and no corpus luteum in about one-third. Proliferative endometrium was shown in 34.0% of the FM group.

CONCLUSION

(1) FM with an incidence of 27.0% might be an important cause of infertility. (2) FM results finally in follicular atresia or multiple immature luteinized follicles.

A possible basic cortical microcircuit called "cascaded inhibition." Results from cortical network models and recording experiments from striate simple cells

The robust behavior, the degree of response linearity, and the aspect of contrast gain control in visual cortical simple cells are (amongst others) the result of the interplay between excitatory and inhibitory afferent and intracortical connections. The goal of this study was to suggest a simple intracortical connection pattern, which could also play a role in other cortical substructures, in order to generically obtain these desired effects within large physiological parameter ranges. To this end we explored the degree of linearity of spatial summation in visual simple cells experimentally and in different models based on half-wave rectifying cells ("push-pull models"). Visual cortical push-pull connection schemes originated from antagonistic motor-control models. Thus, this model class is widely applicable but normally requires a rather specific design. On the other hand we showed that a more generic version of a push-pull model, the so-called cascaded inhibitory intracortical connection scheme, which we implemented in a biologically realistic simulation, naturally explains much of the experimental data. We investigated the influence of the afferent and intracortical connection structure on the measured linearity of spatial summation in simple cells. The analysis made use of the relative modulation measure, which is easy to apply but is limited to moving sinusoidal grating stimuli. We introduced two basic push-pull models, where the order of threshold nonlinearity and linear summation is reversed. Very little difference is observed with the relative modulation measure for these models. Alterative models, like half-wave squaring models, were also briefly discussed. Of all model parameters, the ratio of excitation to inhibition in the simple cell exerts the most crucial influence on the relative modulation. Linearity deteriorates as soon as excitatory and inhibitory inputs are imbalanced and the relative modulation drops. This prediction was tested experimentally by extracellular recordings from cat area 17 simple cells and we found that about 62% showed a significant deviation from linear behavior. The problem that individual basic push-pull models are hard to distinguish experimentally led us to suggest a different solution. In order to generically account for the observed behavior (e.g., imbalance of excitation versus inhibition), we suggested a rather generic version of a push-pull model where it no longer mattered about (the hard-to-distinguish) fine differences in connectivity. Thus, we introduced a new class of biophysically realistic models ("cascaded inhibition"). This model class requires very little connection specificity and is therefore highly robust against parameter variations. Up to 25 cells are connected to each target cell. Thereby a highly interconnected network is generated, which also leads to disinhibition at some parts of an individual receptive field. We showed that the performance of these models simulates the degree of linearity and its variability in recal simple cells with comparatively high accuracy. This behavior can be explained by the self-regulating properties of a cascaded inhibitory connection scheme by which the balance between excitation and inhibition at a given cell is improved by the joint network effects. The virtues and the generic design of this connection pattern, therefore, allow to speculate that it is used also in other parts of the cortex.

[Solid-phase microextraction of dichlorvos from white spirits]

DDVP was isolated from white spirits using Solid-Phase Microextraction (SPME) technique, and determined by wide-bore capillary gas chromatography (GC) coupling a flame ionization detector. This method had an excellent linearity among 0.5-12 mg/L. Correlation coefficient and minimum detectable concentration were 0.9983 and 0.05 mg/L respectively. This method enables the extraction, the enrichment and the injection to integrate into a single step, and it was free-solvent in whole process. SPME is an advanced technique for the extraction and analysis of the samples.

Distribution of endotoxins in tissues and circulation and its effects following hemorrhagic shock

OBJECTIVE

To systemically investigate 1) distribution of endogenous endotoxin (ET) in tissues and circulation; 2) its relationship with shock duration and organ damage; and 3) its possible mechanism after hemorrhagic shock.

METHODS

To further elucidate the intrinsic relationship between endogenous endotoxin translocation and hemorrhagic shock, the present study systematically investigated the distribution of endogenous ET into the liver, lungs, kidneys and circulation, and the relationship between ET levels and the corresponding organ dysfunction with limulus amebocyte lysate (LAL) chromogenic assay following hemorrhagic shock in rats.

RESULTS

It was found that ET levels in hepatic homogenate markedly increased (P = 0.09) 1.5 hours following shock compared with that in the sham group. After resuscitation, ET levels in hepatic, pulmonary and renal tissues were all significantly elevated. The levels kept increasing with the prolonged experimental time, and reached as high as 3.88 +/- 0.95 EU (endotoxin unit)/g in the livers, 2.53 +/- 1.46 EU/g in the lungs and 2.51 +/- 0.89 EU/g in the kidneys 12 hours after shock. ET levels in plasma reached a peak of 1.13 +/- 0.42 EU/ml at 1 hour following resuscitation, then rapidly decreased to the sham levels 3 hours following resuscitation. There was a close relationship between endotoxin translocation and shock duration. Correlation analysis further indicated that the changes in glutamic-pyruvic transaminase (GPT), blood urea nitrogen (BUN) in plasma and angiotensin I-converting exzyme (ACE) in pulmonary homogenate were significantly and positively correlated with the ET levels in the liver, kidneys and lungs after hemorrhagic shock.

CONCLUSIONS

Hemorrhagic shock can induce obvious endogenous ET translocation, which is closely related to the shock duration. Although only transient endotoxemia occurs after hemorrhagic shock, ET can massively accumulate in tissues (liver, lungs and kidneys), and may play an important role in the development of shock.

Effect of hemorrhagic shock on endotoxin-induced TNF production and its molecular mechanism in rats

The present study was designed to investigate the production of tumor necrosis factor alpha (TNF alpha) induced by low-dose (1 microgram/kg) lipopolysaccharide (LPS) and its cellular source after hemorrhagic shock (HS) in rats, and to further analyze the mechanism for increased sensitivity to LPS through looking at expression of lipopolysaccharide-binding protein (LBP) mRNA in the liver, lungs and kidneys. It was found in vivo that plasma TNF alpha levels in the HS + LPS group were 20-fold higher than that in the HS group (P < 0.01), and 2.7-fold higher than that in the LPS group (P < 0.05). It was shown in vitro that the capacity of peripheral white blood cells to produce TNF alpha in response to LPS stimulation was significantly decreased by 126% (P < 0.01) and 57% (P < 0.05) compared with pre-shock levels and the sham group respectively at the end of resuscitation following shock, and was still markedly decreased 3 hours after resuscitation, while the capacity of Kupffer cells was significantly increased by 110% compared with the sham group (P < 0.01) after shock and resuscitation. Results from RT-PCR showed that expression of LBP mRNA in the liver, lungs and kidneys was increased after shock and resuscitation. It is suggested that hemorrhagic shock could significantly enhance endotoxin-induced TNF alpha production, which might be due to up-regulation of LBP expression in tissues after shock, and tissue macrophages might be the main source of cytokine production.

[Increased sensitivity to endotoxin and its molecular mechanism after hemorrhagic shock]

OBJECTIVE

To study the increasing sensitivity to endotoxin induced by hemorrhagic shock and its mechanism.

METHODS

Routine biochemical assay, reverse transcription-polymerase chain reaction. (RT-PCR) and cell in situ hybridization were used to investigate the effects of low-level endotoxin under hemorrhagic shock and its possible mechanism.

RESULTS

In rabbits, blood pressure levels were significantly decreased, and plasma lactate and beta-glucuronidase (beta-G) levels increased in hemorrhagic shock (HS) + LPS group, all of which were significantly different from those in the LPS or HS group. All of the animals in the HS + LPS group were dead while those in the LPS or HS group survived 24 hours after shock. The results of RT-PCR showed that expression of lipopolysaccharide-binding protein (LBP) mRNA in the liver, lungs and kidneys was increased in rats after shock and resuscitation. The expression of CD144 mRNA in the peritoneal macrophages in mice was also enhanced after hemorrhagic shock and subsequent resuscitation showed by cell in situ hybridization.

CONCLUSION

Hemorrhagic shock can significantly increase the sensitivity to endotoxin possibly because of up-regulation of LBP/CD14 after shock.

Expression of TNF alpha, IL-1 beta, IL-6 mRNA, release of TNF alpha in vital organs and their relationship with endotoxin translocation following hemorrhagic shock

This study was designed to systematically investigate expression of TNF alpha, IL-1 beta, Il-6 mRNA in the liver, lungs and kidneys, release of TNF alpha in the above tissues, their relationship with hepatic, pulmonary and renal dysfunction, and distribution of endogenous endotoxin in tissues after hemorrhagic shock in mice and rats, with reverse-transcription-polymerase chain reaction, ELISA, etc, to elucidate the kinetics of expression and release of major cytokines in vital organs, their role and mechanism of production in shock. The results were: 1. expression of TNF alpha, IL-1 beta, IL-6 mRNA in vital organs successively increased after hemorrhagic shock and resuscitation, and TNF alpha expression was the first to appear followed by IL-1 beta. Though expression of IL-6 mRNA appeared late, it persisted longer; 2. TNF alpha levels in the liver, lungs and kidneys were all elevated but to different degrees after shock and resuscitation. At 3 hours after resuscitation, TNF alpha levels in the three above tissues were still significantly high, while plasma TNF alpha levels were already decreased to control levels; 3. hepatic, pulmonary and renal functions were damaged to different degrees after hemorrhagic shock, with hepatic dysfunction being the most severe; 4. endotoxin levels in the liver, lungs and kidneys were markedly increased after shock and resuscitation, and paralleled the expression of cytokine genes. In addition, there was significant correlation between changes in endotoxin level in tissues and TNF alpha release in tissues during early shock. It is suggested that expression and release of cytokines in vital organs might play an important role in local organ damage after hemorrhagic shock, and production of cytokines is related to endotoxin translocation.

Orientational and directional selectivities of visual neurons in the superior colliculus of the cat

Based on quantitative analyses of the response characteristics of visual neurons in the superior colliculus to moving optical bar stimuli, it is demonstrated for the first time that the visual neurons in superior colliculus of the cat have, to some extent, orientational selectivity. The significance of this selectivity is discussed in reference to its morphological substrate and physiological functions. In addition, both the directional and orientational selectivities in the superior colliculus are relatively weak when compared with those in the primary visual cortex, and the majority of the neurons prefer upward or downward motion in the visual field.

Quantification of directional and orientational selectivities of visual neurons to moving stimuli

Directional and orientational components usually coexist and are mixed in the cell's overall responses when moving optical stimuli are used to study the response characteristics of visual neurons. While these two properties were quantified with all the previous methods for data analysis, their effects could not be efficiently separated from each other, and thus the analyses were imperfect. In this paper, theoretical evidence and examples are provided to show the defects of the old methods. In order to separate the two components completely, we propose to apply optimal regression analysis with the sine-cosine function series as the fundamental variables. Based on this separation, we defined the orientational selectivity as variation of response strength with orientation and performed integration and averaging to quantify the two properties [cf. Eqs. (5) and (6)]. The present method has the advantages of completeness and accuracy, and can detect some details which would have been missed by other methods. An explanation of the intrinsic implications of the method and our comprehension of directional and orientational selectivities and preferred direction and orientation are also given.

Pharmacokinetics of sustained-release tablets of metoprolol in Chinese

Single and repeated oral doses pharmacokinetic studies of metoprolol sustained-release tablets (Sino-Swed Pharmaceutical Co Ltd) were performed on 12 Chinese healthy subjects in an open randomized crossover manner, using metoprolol tablets from Sweden Astra International Pharmaceutical Co Ltd as control. Drug concentrations in plasma were assayed by gas chromatography-electron-capture detector method. The percent of drug absorbed in vivo at 1, 2, 4, 6, 8 h correlated well with the amount of drug released in vitro at corresponding time (P > 0.05). Pharmacokinetic parameters in Chinese after metoprolol tablets were comparable to the reported data in foreigners.

Pharmacokinetics and relative bioavailability of lomefloxacin preparations in 10 healthy Chinese volunteers

The pharmacokinetics of lomefloxacin tablet and capsule were determined following a single oral dose of 400 mg given to each of 10 Chinese healthy male volunteers in an open, randomized crossover study. Drug concentrations in plasma were assayed by HPLC method. The peak levels in plasma averaged 6.0 +/- 1.3 and 5.9 +/- 1.0 micrograms.ml-1 at 1.3 +/- 0.4 and 1.2 +/- 0.4 h, and the areas under the drug concentration curves were 43 +/- 15 and 44 +/- 13 h.micrograms.ml-1 for lomefloxacin tablet and capsule, respectively. The concentration-time courses after medication conformed to a 1-compartment open model with a first order absorption. Pharmacokinetic parameters after tablet did not differ significantly from the corresponding values after capsule. The bioavailability of tablet was comparable to that of capsule.

Pharmacokinetics and relative bioavailability of ofloxacin tablets in 12 healthy volunteers

Single oral dose of tablet A (Daiichi Pharmaceutical Co Ltd, Japan) and B (Jining Pharmaceutical Factory, Shandong, China) of 300 mg ofloxacin (Ofl) were given to 12 Chinese healthy male volunteers in an open, randomized crossover study. Drug concentrations in serum and urine were assayed by HPLC and partial least squares spectrophotometric method, respectively. The serum concentration-time course after medication conformed to a 2-compartment open model with a first order absorption. Pharmacokinetic parameters after tablet B did not differ significantly from the corresponding values after tablet A. The bioavailability of tablet B was comparable to that of tablet A.