Antimicrobial and disinfectant resistance of Escherichia coli isolated from giant pandas

AIMS

The study aims to demonstrate the antimicrobial and disinfectant resistance phenotypes and genotypes of Escherichia coli isolates obtained from giant pandas (Ailuropoda melanoleuca).

METHODS AND RESULTS

Antimicrobial testing was performed according to the standard disk diffusion method. The minimal inhibitory concentrations (MICs) of disinfectants were determined using the agar dilution method. All isolates were screened for the presence of antimicrobial and disinfectant resistance genes and further analysed for genetic relatedness by pulse-field gel electrophoresis (PFGE). Results showed that 46·6% of the isolates were resistant to at least one antimicrobial. Escherichia coli isolates showed resistance to fewer antimicrobials as panda age increased. Among antimicrobial-resistant E. coli isolates, the antimicrobial resistance genes blaCTX-M (88·2%) and sul1 (92·3%) were most prevalent. The disinfectant resistance genes emrE, ydgE/ydgF, mdfA and sugE(c) were commonly present (68·2-98·9%), whereas qac and sugE(p) were relatively less prevalent (0-21·3%). The frequencies of resistance genes tended to be higher in E. coli isolated in December than in July, and PFGE profiles were also more diverse in isolates in December. The qacEΔ1 and sugE(p) genes were higher in adolescent pandas than in any other age groups. PFGE revealed that antimicrobial resistance correlated well with sampling time and habitat.

CONCLUSIONS

This study demonstrated that antimicrobial and disinfectant resistance was common in giant panda-derived E. coli, and the antimicrobial resistance was associated with sampling time and habitat. Escherichia coli could serve as a critical vector in spreading disinfectant and antimicrobial resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study that demonstrated the phenotypic and genetic characterizations of antimicrobial and disinfectant resistance in E. coli isolates from more than 60 giant pandas. Frequent transfer of pandas to other cages may lead to the dissemination of antimicrobial resistance. The study highlights the need for regularly monitoring the antimicrobial and disinfectant resistance in bacteria from giant pandas.

Occupancy by key transcription factors is a more accurate predictor of enhancer activity than histone modifications or chromatin accessibility

Background

Regulated gene expression controls organismal development, and variation in regulatory patterns has been implicated in complex traits. Thus accurate prediction of enhancers is important for further understanding of these processes. Genome-wide measurement of epigenetic features, such as histone modifications and occupancy by transcription factors, is improving enhancer predictions, but the contribution of these features to prediction accuracy is not known. Given the importance of the hematopoietic transcription factor TAL1 for erythroid gene activation, we predicted candidate enhancers based on genomic occupancy by TAL1 and measured their activity. Contributions of multiple features to enhancer prediction were evaluated based on the results of these and other studies.

Results

TAL1-bound DNA segments were active enhancers at a high rate both in transient transfections of cultured cells (39 of 79, or 56%) and transgenic mice (43 of 66, or 65%). The level of binding signal for TAL1 or GATA1 did not help distinguish TAL1-bound DNA segments as active versus inactive enhancers, nor did the density of regulation-related histone modifications. A meta-analysis of results from this and other studies (273 tested predicted enhancers) showed that the presence of TAL1, GATA1, EP300, SMAD1, H3K4 methylation, H3K27ac, and CAGE tags at DNase hypersensitive sites gave the most accurate predictors of enhancer activity, with a success rate over 80% and a median threefold increase in activity. Chromatin accessibility assays and the histone modifications H3K4me1 and H3K27ac were sensitive for finding enhancers, but they have high false positive rates unless transcription factor occupancy is also included.

Conclusions

Occupancy by key transcription factors such as TAL1, GATA1, SMAD1, and EP300, along with evidence of transcription, improves the accuracy of enhancer predictions based on epigenetic features.

Electronic supplementary material

The online version of this article (doi:10.1186/s13072-015-0009-5) contains supplementary material, which is available to authorized users.

Morphologic control of Sb-rich Sb2Se3 to adjust its catalytic hydrogenation properties for p-nitrophenol

Sb-rich Sb₂Se₃ with hollow sphere morphology is an efficient catalyst for the hydrogenation of p-nitrophenol.

Five days of head-down-tilt bed rest induces noninflammatory shedding of L-selectin

Head-down-tilt bed rest (HDTBR) is a popular model, simulating alterations of gravitation during space missions. The aim of this study was to obtain a better insight into the complexly orchestrated regulations of HDTBR-induced immunological responses, hypothesizing that artificial gravity can mitigate these HDTBR-related physiological effects. This crossover-designed 5 days of HDTBR study included three protocols with no, or daily 30 min of centrifugation or 6 × 5 min of centrifugation. Twelve healthy, male participants donated blood pre-HDTBR, post-HDTBR, and twice during HDTBR. Cellular immune changes were assessed either by enumerative and immune cell phenotyping assays or by functional testing of responses to either recall antigens or receptor-dependent activation by chemotactic agents N-formyl-methionyl-leucyl-phenylalanine (fMLP) and with TNF-α. The expression of the adhesion molecule L-selectin (CD62L) on the surface of granulocytes and its shedding into plasma samples were measured. In parallel, other humoral factor, such as interleukin-6 and interleukin-8, parameters of endothelial damage (glycocalyx) were determined. Hematocrit and hemoglobin were significantly increased during HDTBR. Although immune functional tests did not indicate a change in the immune performance, the expression of CD62L on resting granulocytes was significantly shed by 50% during HDTBR. Although the latter is normally associated to an activation of inflammatory innate immune responses and during interaction of granulocytes with the endothelium, CD62L shedding was, however, not related either to a systemic inflammatory alteration or to shedding of the endothelial glycocalyx during bed rest. This suggests a noninflammatory or “mechanical” shedding related to fluid shifts during head-down intervention and not to an acute inflammatory process.

Elevated snoRNA biogenesis is essential in breast cancer

Hyperactive ribosomal biogenesis is widely observed in cancer, which has been partly attributed to the increased rDNA transcription by Pol I in cancer. However, whether small nucleolar RNAs (snoRNAs), a class of non-coding RNAs crucial in ribosomal RNA (rRNA) maturation and functionality, are involved in cancer remains elusive. We report that snoRNAs and fibrillarin (FBL, an enzymatic small nucleolar ribonucleoprotein, snoRNP) are frequently overexpressed in both murine and human breast cancer as well as in prostate cancers, and significantly, that this overexpression is essential for tumorigenicity in vitro and in vivo. We demonstrate that when the elevated snoRNA pathway is suppressed, the tumor suppressor p53 can act as a sentinel of snoRNP perturbation, the activation of which mediates the growth inhibitory effect. On the other hand, high level of FBL interferes with the activation of p53 by stress. We further show that p53 activation by FBL knockdown is not only regulated by the ribosomal protein-MDM2-mediated protein stabilization pathway, but also by enhanced PTB-dependent, cap-independent translation. Together, our data uncover an essential role of deregulated snoRNA biogenesis in tumors and a new mechanism of nucleolar modulation of p53.

We are all in this together: working towards a holistic understanding of self-harm

Self-harm is a widespread and controversial issue in contemporary society. Statistics are based on reported incidents and therefore do not accurately reveal prevalence, as self-harm is often a hidden behaviour. This highlights the essential need for practitioners and society to work towards reducing the stigma surrounding self-harm. This paper goes some way towards understanding the impact of self-harm on individuals and communities. It begins by exploring terminologies and definitions of self-harm and discusses the importance of sensitivity in language use relating to self-harm. It continues by examining types of self-harm and subsequently presents life experiences that may contribute to the onset of self-harm. The paper elucidates the cultural, historical and religious origins of self-harm, indicating the ways in which self-harm has evolved with us as part of our humanity. Moreover, literature relating to the significance of stigma and attitudes is examined, followed by issues around psychiatric diagnoses pertaining to self-harm. The paper concludes by synthesizing literature relevant to the relationship between self-harm and suicide.

Alterations of fatty acid β-oxidation capability in the liver of ketotic cows

Dairy cows are highly susceptible to ketosis after parturition. In the present study, we evaluated the expression of fatty acid β-oxidation-related enzymes in the liver of ketotic (n=6) and nonketotic (n=6) cows. Serum levels of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and glucose were determined by using standard biochemical techniques. The mRNA abundance and protein content of acyl-CoA synthetase long-chain (ACSL), carnitine palmitoyltransferase I (CPT I), carnitine palmitoyltransferase II (CPT II), acyl-CoA dehydrogenase long chain (ACADL), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS), and acetyl-CoA carboxylase (ACC) were evaluated by real-time PCR and ELISA. We found that serum glucose levels were lower in ketotic cows than in nonketotic cows, but serum BHBA and NEFA concentrations were higher. Messenger RNA and protein levels of ACSL were significantly higher in livers of ketotic cows than those in nonketotic cows. In contrast, mRNA levels of CPT I and mRNA and protein levels of CPT II, ACADL, HMGCS, and ACC were decreased in the liver of ketotic cows. Serum NEFA concentration positively correlated with ACSL protein levels and negatively correlated with protein levels of CPT II, HMGCS, ACADL, and ACC. In addition, serum BHBA concentration negatively correlated with protein levels of CPT II, HMGCS, and ACADL. Overall, fatty acid β-oxidation capability was altered in the liver of ketotic compared with nonketotic cows. Furthermore, high serum NEFA and BHBA concentrations play key roles in affecting pathways of fatty acid metabolism in the liver.

SU-E-I-75: A New Method for Prostate Cancer Localization Using Multispectral MRI

PURPOSE

To develop a new method for automatic localization of prostate cancer using multispectral MRI data.

METHODS

Multispectral MRI including MR spectroscopic imaging (MRSI), T2 weighted MRI, diffusion weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI, has been used for cancer target localization. The combination of multiple MRI imaging technologies provides more useful information than one single technology alone about prostate cancer and has advantages for target definition in radotherapy treatment and quantitative evaluation of tumor response. However, manual cancer localization using multispectral MRI dataset is a tedious task and prone to inter-/intra-observer variability. Automatic localization methods using multispectral MRI data is highly desired. In this paper, a fuzzy fusion framework for automatically localizing prostate cancer with multispectral MRI data is presented. Firstly, for each kind of MRI images, a membership function is created to calculate the membership-degrees of image elements belonging to cancer region. Secondly, a fuzzy fusion operator is used to fuse different membership- degrees corresponding to the same regions. Lastly, the Result of fusion is further adjusted with fuzzy region growing process, leading to the final membership-degree map. And cancer volume is finally defined by setting up a threshold on the map.

RESULTS

The new method was tested with one multispectral MRI patient dataset and results from our experimental study are compared with the one obtained form a manual method performed by an experienced pathologist. Quantitative analysis shows that the specificity is 98.89%, sensitivity is 62.85% and accuracy is 95.42%, respectively. It illustrates the feasibility of utilizing this framework in the clinical application.

CONCLUSIONS

The feasibility study shows the new method reported in this paper achieves automatic localization for prostate cancer and can be easily implemented in clinical applications. We are currently conducting a clinical study for testing the effectiveness and reliability, and further developing this method. *supported by NSFC-81171342 support by National Science Foundation of China (NSFC-81171342).

Changes of serum omentin levels and relationship between omentin and adiponectin concentrations in type 2 diabetes mellitus

BACKGROUND

Omentin has recently been characterized as a potent insulin-sensitizing adipokine, but its pathophysiologic roles in humans remain largely unknown.

OBJECTIVE

To investigate the change of fasting serum omentin levels and evaluate the relationship of omentin with adiponectin in patients with type 2 diabetes mellitus.

DESIGN

35 patients with newly diagnosed type 2 diabetes (T2DM), 35 patients with impaired glucose regulation (IGT) and 35 patients with normal glucose tolerance (NGT) participated in this study. Fasting serum omentin and adiponectin levels were measured by enzyme-linked immunosorbent assay. The relationship between serum omentin, serum adiponectin levels and metabolic parameters was also analyzed.

RESULTS

Fasting serum omentin levels were significantly lower in T2DM and IGT groups than in NGT group (16.75±1.71 vs. 18.62±1.22 vs. 24.60±1.43 ng/ml, all P<0.01). Obesity subjects had significantly lower serum omentin levels than normal body weight subjects ( P<0.01 or P<0.05). Female subjects had moderately higher fasting serum omentin levels than male subjects. Fasting serum adiponectin levels showed a similar variation trend to omentin in T2DM and NGT groups, obesity and normal body weight subjects, female and male subjects. Fasting serum omentin levels were negatively correlated with HOMA-IR and positively correlated with adiponectin. Moreover, HOMA-IR and adiponectin were the independently predictors of fasting serum omentin levels.

CONCLUSIONS

Serum omentin levels possibly play an important role in the pathogenesis of insulin resistance and diabetes. More importantly, there is such a close connection between serum omentin and adiponectin levels that regulation of omentin may be dependent on adiponectin.

Effect of Saccharomyces cerevisiae fermentation product on ruminal fermentation and nutrient utilization in dairy cows

The goal of this experiment was to investigate the effect of yeast culture (Saccharomyces cerevisiae) on rumen fermentation, nutrient utilization, and ammonia and methane emission from manure in dairy cows. Eight ruminally cannulated Holstein cows were allocated to 2 dietary treatments in a crossover design. Treatments were control (no yeast culture) and XP (yeast culture, fed at 56 g/head per day; XP, Diamond V Mills Inc., Cedar Rapids, IA). Dry matter intake, milk yield, milk composition, and body weight were similar between treatments. Milk urea nitrogen concentration was also not affected by treatment. Rumen pH was similar between the control and XP treatments, but rumen ammonia concentration tended to be lower with XP than with the control. Treatment had no effect on concentrations of total or individual volatile fatty acids, protozoal counts, polysaccharide-degrading activities (except amylase activity that tended to be increased by XP), or methane production in the rumen. Urinary N losses did not differ significantly between treatments, but allantoin and total purine derivative excretions and the estimated microbial N outflow from the rumen tended to be increased by XP compared with the control treatment. Total-tract apparent digestibility of dietary nutrients was not affected by XP. Milk fatty acid composition was also not altered by XP supplementation. Cumulative (253 h) ammonia and methane emissions from manure, measured in a steady-state gas emission system, were slightly decreased by XP. Overall, the yeast culture tested had little effect on ruminal fermentation, digestibility, or N losses, but tended to reduce rumen ammonia concentration and increase microbial protein synthesis in the rumen, and decreased ammonia and methane emissions from manure.

A localized multimeric anchor attaches the Caulobacter holdfast to the cell pole

Caulobacter crescentus attachment is mediated by the holdfast, a complex of polysaccharide anchored to the cell by HfaA, HfaB and HfaD. We show that all three proteins are surface exposed outer membrane (OM) proteins. HfaA is similar to fimbrial proteins and assembles into a high molecular weight (HMW) form requiring HfaD, but not holdfast polysaccharide. The HfaD HMW form is dependent on HfaA but not on holdfast polysaccharide. We show that HfaA and HfaD form homomultimers and that they require HfaB for stability and OM translocation. All three proteins localize to the late pre-divisional flagellar pole, remain at this pole in swarmer cells, and localize at the stalk tip after the stalk is synthesized at the same pole. Hfa protein localization requires the holdfast polysaccharide secretion proteins and the polar localization factor PodJ. An hfaB mutant is much more severely deficient in adherence and holdfast attachment than hfaA and hfaD mutants. An hfaA, hfaD double mutant phenocopies either single mutant, suggesting that HfaB is involved in holdfast attachment beyond secretion of HfaA and HfaD. We hypothesize that HfaB secretes HfaA and HfaD across the outer membrane, and the three proteins form a complex anchoring the holdfast to the stalk.

Late presentation of aorto-right ventricular fistula and associated aortic regurgitation following penetrating chest trauma

We present a case in which a 39-year-old man was assaulted in 2002 and sustained penetrating chest trauma. He was treated conservatively, and presented six years later with exertional dyspnoea and a continuous murmur. Echocardiography detected an aorta-right ventricular fistula and an important aortic regurgitation. The aorta-right ventricular fistula was repaired and the aortic valve was replaced with a mechanical prosthesis. Traumatic aorto-right ventricular fistulas and aortic regurgitation are often masked by the primary injury and may take months or years to become clinically evident.

Conservative management of ovarian cysts in pregnancy during third trimester and intrapartum

We treated two patients with large ovarian cysts in pregnancy conservatively. In both cases, aspiration of the cysts under ultrasound guidance allowed successful vaginal delivery. In one case, the cyst fluid reaccumulated, and required further aspiration in labour. In both cases, benign ovarian cysts were removed laparoscopically at a later date. Various strategies for dealing with ovarian cysts in pregnancy are discussed.

Origination of chimeric genes through DNA-level recombination

Comparative genomics is rapidly bringing to light the manifold differences that exist within and between species on the molecular level. Of fundamental interest are the absolute and relative amounts of the genome dedicated to protein coding regions. Results thus far have shown surprising variation on both the polymorphism and divergence levels. As a result, there has been an increase in efforts aimed to characterize the underlying genetic mechanisms and evolutionary forces that continue to alter genomic architecture. In this review we discuss the formation of chimeric genes generated at the DNA level. While the formation of chimeric genes has been shown to be an important way in which coding regions of the genome evolve, many of the detailed studies have been limited to chimeric genes formed through retroposition events (through an RNA intermediate step). Here we provide a short review of the reported mechanisms that have been identified for chimeric gene formations, excluding retroposition-related cases, and discuss several of the evolutionary analyses carried out on them. We emphasize the utility chimeric genes provide for the study of novel function. We also emphasize the importance of studying chimeric genes that are evolutionarily young.

Combination therapy with gefitinib and capecitabine in metastatic breast cancer (MBC): A phase I trial

10564

Background: Preclinical models have suggested synergy between the EGFR tyrosine kinase inhibitor gefitinib (G) and the 5-FU prodrug capecitabine (C), an active treatment for MBC. This phase I study was designed to explore the safety of this all-oral regimen in patients (pts) with MBC. Methods: Pts were treated in sequential cohorts (n = 3–6) using a fixed dose of G (250 mg qd continuously) and escalating doses of C (1500 mg/m2/day, 1750 mg/m2/day, and 2000 mg/m2/day) in a 21-day cycle. An additional 10 pts were enrolled in a validation cohort at the maximum tolerated dose (MTD). Dose limiting toxicity (DLT) was defined during the first cycle as any grade 3/4 toxicity or a delay >3 weeks due to unresolved toxicity. The primary endpoint was safety; secondary endpoints included assessments of tumor response (using RECIST criteria), adherence to the oral regimen, and biomarker measurements. Results: 19 pts were enrolled; the mean age was 49 y, 58% of tumors were hormone receptor positive, and 10% were HER2 positive. The mean number of prior MBC chemotherapy regimens was 1.2 and 74% had visceral spread. No pts in dose escalation cohorts had DLT during cycle 1. The 10 pts in the validation cohort (MTD C 2000 mg/m2) had 3 DLTs in cycle 1 and 1 DLT in cycle 2 (95% CI 12–74%). For all pts at C 2000 mg/m2 (n = 13), there was no grade 4 toxicity, however 5 (38%) had grade 3 toxicity, 7 (54%) required a C dose reduction, and 2 (15%) came off study for persistent toxicity. 3 pts (23%) experienced grade 3 diarrhea, and 4 pts (31%) had moderate to severe hand/foot syndrome. There were no objective responses (PR or CR) observed out of 18 evaluable pts. The mean number of completed cycles of therapy was 4.8, and 3 pts (16%) were treated for > 24 weeks. An exploratory analysis of serum EGFR measurements demonstrated no association of pre- or post-therapy values with lack of progression. Monitoring adherence to oral therapy using a microelectronic monitoring system (MEMS) was feasible, and detailed data will be presented. Conclusions: In this phase I dose escalation trial of G/C therapy in women with MBC, treatment was generally well tolerated, with a confirmed C MTD of 2000 mg/m2. Moderate toxicity and dose reductions were common. In this small cohort, the G/C combination did not appear to have substantial anti-tumor activity.

[Table: see text]

Cetacean captures, strandings and mortalities in South Australia 1881-2000, with special reference to human interactions

This study summarizes 660 events involving captured, live-stranded and dead cetaceans in South Australia between 1881 and 2000. Emphasis is placed on records (n = 361) during 1985-2000 when an active necropsy programme was underway. Average number of events per year was 30.4 and the most common species were the short-beaked common dolphin (Delphinus delphis) and Indo-Pacific bottlenose dolphin (Tursiops aduncus). Records were assigned to nine categories of circumstance/cause of death. Summarizing the total database, 60% were unknown circumstance, 22% not obviously anthropogenic, 13% unintentional human-related and 5% intentional human-related. In the data set of records for 1985-2000, 50% were unknown, 25% were not obviously anthropogenic, 20% were unintentional humanrelated and 5% were intentional killings. Non-anthropogenic circumstances included neonatal deaths, live strandings, significant diseases, shark attacks and choking. Cornynebacterium ulcerans is recorded for the first time in a cetacean. Unintentional circumstances included entanglement in fishing and aquaculture equipment (17% of necropsied carcasses from 1985-2000) and boat strikes. Intentional human-related circumstances were captures for live display and illegal killing. Five percent of the necropsied carcasses during 1985-2000 were attributed to shootings or stabbings/spearings. There is need for a formal reporting procedure for marine mammal deaths and human interaction involving injury and for steps to be taken to reduce human impacts.

[The relationship between surgical staging, pathologic grading, operative type and postoperative recurrence in giant cell tumor of bone]

Sixty-eight surgical procedures of 58 patients with Giant Cell Tumor of Bone(GCT) were followed up over two years. The recurrence rate of GCT was Stage 1: 0 in 5, Stage 2: 15.4% in 39 and Stage 3: 37.5% in 24. It was significantly higher in Stage 3 than in Stage 2 (P < 0.05). The recurrence rate of GCT in Stage 2 was 30.8% in 13 intralesional curettage, and 0 in 17 wide or radical resection(P < 0.05). We conclude that the surgical staging of GCT has important value in predicting postoperative recurrence, in accurately evaluating the operative efforts and in guiding treatment, and that the operative type is a significant factor effecting on the recurrence of GCT.

[Analysis of complications and deaths in aged patients with obstructive jaundice]

The reasons of complications and deaths in 98 aged patients with obstructive jaundice were analysed in the paper. Among them, 52 cases were diagnosed as benign obstruction, 46 cases as malignant obstruction; 92 patients were treated by surgical management(15 died), 6 patients were treated without operation(4 died). The results showed that effective management on time and intensive perioperative care are important to minimize the mortality rate. Malignant obstructive jaundice was more harmful to the patients' renal function no the mortality rate would be increased. The operations, internal drainage and pressure reduction of biliary duct, were performed on time, thus the survival rate was improve.

ExInt: an Exon Intron Database

The Exon/Intron Database (ExInt) stores information of all GenBank eukaryotic entries containing an annotated intron sequence. Data are available through a retrieval system, as flat-files and as a MySQL dump file. In this report we discuss several implementations added to ExInt, which is accessible at http://intron.bic.nus.edu.sg/exint/newexint/exint.html.

Intravenous tissue-type plasminogen activator therapy for ischemic stroke: Houston experience 1996 to 2000

CONTEXT

Intravenous tissue-type plasminogen activator (tPA) therapy using the National Institute of Neurological Disorders and Stroke criteria has been given with variable safety to less than 5% of the patients who have ischemic strokes nationwide. Our center is experienced in treating large numbers of stroke patients with intravenous tPA.

OBJECTIVE

To report our total 4-year experience in the treatment of consecutive patients who had an ischemic stroke.

DESIGN

Prospective inception cohort registry of all patients seen by our stroke team and an additional retrospective medical record review of all patients treated between January 1, 1996, and June 1, 2000.

SETTING

A veteran stroke team composed of fellows and stroke-specialty faculty servicing 1 university and 3 community hospitals in a large urban setting.

PATIENTS

Consecutive patients with ischemic stroke treated within the first 3 hours of symptom onset.

INTERVENTION

According to the National Institute of Neurological Disorders and Stroke protocol, 0.9 mg/kg of intravenous tissue-type plasminogen activator was administered.

MAIN OUTCOME MEASURES

Number and proportion treated, patient demographics, time to treatment, hemorrhage rates, and clinical outcome.

RESULTS

A total of 269 patients were treated between January 1, 1996, and June 1, 2000. Their mean age was 68 years (age range, 24-93 years); 48% were women. This represented 9% of all patients admitted with symptoms of cerebral ischemia at our most active hospital (over the final 6 months, 13% of all patients with symptoms of cerebral ischemia and 15% of all acute ischemic stroke patients). Before treatment the mean +/- SD National Institutes of Health Stroke Scale (NIHSS) score was 14.4 +/- 6.1 points (median, 14 points; range, 4-33 points). A tPA bolus was given at 137 minutes (range, 30-180 minutes); 28% of the patients were treated within 2 hours. The mean door-to-needle time was 70 minutes (range, 10-129 minutes). The symptomatic intracerebral hemorrhage rate was 5.6% of those patients with a second set of brain scans (4.5% of all patients), with a declining trend from 1996 to 2000. Protocol violations were found in 13% of all patients; the symptomatic intracerebral hemorrhage rate in these patients was 15%. At 24 hours, the NIHSS score was 10 +/- 8 points (median, 8 points; range, 0-36 points). In-hospital mortality was 15% and the patients' discharge NIHSS scores were 7 +/- 7 points (median, 3 points; range, 0-35 points).

CONCLUSIONS

Intravenous tPA therapy can be given to up to 15% of the patients with acute ischemic stroke with a low risk of symptomatic intracerebral hemorrhage. Successful experience with intravenous tPA therapy depends on the experience and organization of the treating team and adherence to published guidelines.

Evolution of novel genes

Much progress in understanding the evolution of new genes has been accomplished in the past few years. Molecular mechanisms such as illegitimate recombination and LINE element mediated 3' transduction underlying exon shuffling, a major process for generating new genes, are better understood. The identification of young genes in invertebrates and vertebrates has revealed a significant role of adaptive evolution acting on initially rudimentary gene structures created as if by evolutionary tinkers. New genes in humans and our primate relatives add a new component to the understanding of genetic divergence between humans and non-humans.

Kinetic measurements of cell surface E-selectin/carbohydrate ligand interactions

Selectin/ligand interactions initiate the multistep adhesion and signaling cascades in the recruitment of leukocytes from circulation to inflamed tissues and may also play a role in tumor metastasis. Kinetic properties of these interactions are essential determinants governing blood-borne cells' tethering to and rolling on the vessel wall. Extending our recently developed micropipette method, we have measured the kinetic rates of E-selectin/ligand interactions. Red cells coated with an E-selectin construct were allowed to bind HL-60 or Colo-205 cells bearing carbohydrate ligands. Specific adhesions were observed to occur at isolated points, the frequency of which followed a Poisson distribution. These point attachments were formed at the same rate with both the HL-60 and Colo-205 cells (0.14 +/- 0.04 and 0.13 +/- 0.03 microm2 s(-2) per unit density of E-selectin, respectively) but dissociated from the former at a rate twice as fast as did from the latter (0.92 +/- 0.23 and 0.44 +/- 0.10 s(-1), respectively). The reverse rates agree well with those measured by the flow chamber. The forward rates are orders of magnitude higher than those of Fcgamma receptors interacting with IgG measured under similar conditions, consistent with the rapid kinetics requirement for the function of E-selectin/ligand binding, which is to capture leukocytes on endothelial surfaces from flow.

Aspartyl proteinase genes from apicomplexan parasites: evidence for evolution of the gene structure

Aspartyl proteinases are a widely distributed family of enzymes. All vertebrate aspartyl proteinases share a conserved nine-exon gene structure, but in other organisms the structure of aspartyl proteinase genes varies considerably. The exon-intron patterns generally reflect phylogeny based on amino acid sequences. However, close comparison of these gene structures reveals some striking features, such as the conservation of intron positions and intron phases between aspartyl proteinases from nematodes and apicomplexans. Here, we discuss the implications of gene structure for the possible evolution of the aspartyl proteinase family, with particular reference to the plasmepsins of Plasmodium falciparum and eimepsin from Eimeria tenella.

[Studies on transference of hydrogenase genes of Rhizobium arachis]

The hydrogen-uptake genes were transferred into wild Rhizobium arachis Ra strains (Hup-, Nif+, Apr) by triparental mating using pRK2013 as help plasmid. A transconjugant R. arachis Rz34-2(Hup+, Nif+, Apr, Tcr) which expressed high activities of hydrogenase and nitrogenase under free-living and symbiotic state was screened. Peanut inoculation test with recipient R. arachis Ra34, transcojugant Rz34-2 and control strain R. arachis L8-3 (Hup+, Nif+) was carried out respectively. The results showed that, compare to treatment without inoculation, inoculation with R. arachis Ra34 and R. arachis L8-3, the dry weight of leaf inoculated with transconjuant Rz34-2 increased 6.2%, 7.6% and 6.3% respectively; the N-content of seed increased 8.8%, 10.0% and 6.0%; the output increased 18.8%, 10.5% and 10.7%. This suggested that legume plants inoculated with Rhizobium strains (Hup+) were more efficient to accumulate N and to increase its output.

An outcome study of breast reconstruction: presurgical identification of risk factors for complications

BACKGROUND

Breast reconstruction following mastectomy has been shown to have a salutary effect on the overall psychological well-being of women being treated for breast cancer. Unfortunately, however, not every patient is an ideal candidate for reconstruction. Complications stemming from reconstructive surgery can cause significant morbidity, the most important of which may be the delay of subsequent adjuvant antineoplastic therapies, and therefore may not be in the best interests of the patient.

METHODS

A retrospective study was performed on a consecutive series of 123 breast reconstructions in 98 patients, performed by one of two plastic surgeons, in a university setting over a 5-year period, for all surgical outcomes. Specifically, wound-healing complications, infections, and reoperations leading to the potential delay of subsequent chemotherapy or radiotherapy were recorded, and possible risk factors leading to these were sought.

RESULTS

Three presurgical risk factors were found to have a statistically significant influence on the development of complications following breast reconstruction. These were: (1) increasing obesity, defined by the body mass index, (2) an active or recent (<5 year) history of cigarette smoking, and (3) a history of previous radiation exposure. Odds ratios were used to describe the magnitude of the effect of each factor for the development of complications. An ordinal regression analysis was used to create a nomogram based on this information that can be used to calculate any individual patient's presurgical risk for developing major complications following breast reconstruction, based on the presence of these factors.

CONCLUSIONS

It is possible, based on the presence of specific presurgical risk factors, to predict the probability of developing major complications following breast reconstruction. This information can be useful to the referring physician and plastic surgeon alike in determining which patients are the best candidates for breast reconstruction and which type of reconstruction would be best suited for each individual patient.

A comparison of the Ameroid constrictor versus ligation in the surgical management of single extrahepatic portosystemic shunts

Twenty-two dogs were managed surgically for a single extrahepatic portosystemic shunt; 12 with surgical ligation and 10 with an Ameroid constrictor. Utilization of the Ameroid constrictor significantly decreased surgery time to approximately half that of the ligation technique. A decreased intraoperative and postoperative complication rate was noted with the Ameroid constrictor group. Follow-up evaluation demonstrated comparable efficacy when comparing surgical techniques. The Ameroid constrictor offered a surgical occlusion technique for management of a single extra-hepatic portosystemic shunt that was equally effective to ligation while shortening surgical time and minimizing the risks that are commonly associated with ligation of the shunting vessel.