[Relationship between gut microbiota and its metabolite dysregulation and postoperative cognitive dysfunction in elderly male C57BL/6J mice after laparotomy exploration]

Objective: To explore the relationship between gut microbiota and its metabolite dysregulation and postoperative cognitive dysfunction in elderly male C57BL/6J mice after laparotomy exploration. Methods: A total of 48 specific pathogen-free (SPF) male C57BL/6J mice, aged 16-17 months, were divided into two groups by random number table method: control group (n=24) and operation group (n=24). Mice in the operation group were induced with 1.4% isoflurane for 15 minutes, followed by a 10 minutes exploratory laparotomy anesthetized with 1.4% isoflurane and 100% oxygen, and anesthesia continued for 2 hours after surgery. Mice in control group were put in 100% oxygen for 2 hours. Feces and venous blood samples of both groups were collected 48 hours after surgery. Changes in the abundance and diversity of intestinal bacteria in the feces were detected by 16S rDNA gene sequencing. Functional changes of fecal metabolic profiles were detected by liquid chromatography tandem mass spectrometry (LC/MS) metabolomics and differential metabolite functions were analyzed. The serum level of interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) were detected by Enzyme-linked immunosorbent assay (ELISA). The cognitive function of the mice was detected by Morris water maze test 3 days after operation. Results: The postoperative escape latency of mice in control group and operation group was (22.0±4.9) and (35.0±5.1) s, and the target quadrant residence time was (26.0±3.7) and (16.0±2.9) s, respectively. Compared with the control group, the postoperative escape latency of mice in the operation group was prolonged (P=0.035), and the residence time in the target quadrant was reduced (P=0.006). The difference of intestinal flora between the two groups was comparable. The expression levels of Escherichia coli, shigella and clostridium in the operation group were up-regulated, while the expression levels of rumen bacteria and butyricobacteria were down-regulated. Fecal metabolic profiles of mice in control group and operation group were obtained by LC/MS, and 14 and 21 different metabolites were screened in positive and negative ion modes, respectively. The different metabolites in positive ion mode were glutamic acid, 2-indoleic acid, kynuuric acid and glyceraldehyde. The negative ion pattern differential metabolites are methionine, aspartic acid, L-threonine, tyrosyl-threonine and 5-hydroxyindole-3-acetic acid. The identified differential metabolite pathways are mainly involved in amino acid, fatty acid and tryptophan metabolism and nucleotide synthesis. There were no significant differences in serum levels of IL-1β, IL-6 and TNF-α between the two groups (all P>0.05). Conclusion: The dysregulated changes of gut microbiota and its metabolites are correlated with the occurrence of postoperative cognitive dysfunction in elderly male C57BL/6J mice. Anesthesia and surgery alter the structure of mice intestinal bacteria on the level of abundance, and change the metabolic balance and feces metabolomic phenotype.

[The effect of deep neuromuscular block combined with low pneumoperitoneum pressure on postoperative pain in patients undergoing laparoscopic radical colorectal surgery]

Objective: To investigate the effect of deep neuromuscular blockade (DNMB) combined with low pneumoperitoneum pressure anesthesia strategy on postoperative pain in patients undergoing laparoscopic colorectal surgery. Methods: This study was a randomized controlled trial. One hundred and twenty patients who underwent laparoscopic colorectal surgery at Cancer Hospital of Chinese Academy of Medical Sciences from December 1, 2022 to May 31, 2023 were selected and randomly divided into two groups by random number table method. Moderate neuromuscular blockade [train of four stimulations count (TOFC)=1-2] was maintained in patients of the control group (group C, n=60) and pneumoperitoneum pressure level was set at 15 mmHg(1 mmHg=0.133 kPa). DNMB [post-tonic stimulation count (PTC)=1-2] was maintained in patients of the DNMB combined with low pneumoperitoneum pressuregroup (group D, n=60) and pneumoperitoneum pressure level was set at 10 mmHg. The primary measurement was incidence of moderate to severe pain at 1 h after surgery. The secondary measurements the included incidence of moderate to severe pain at 1, 2, 3, 5 d and 3 months after surgery, the incidence of rescue analgesic drug use, the doses of sufentanil in analgesic pumps, surgical rating scale (SRS) score, the incidence of postoperative residual neuromuscular block, postoperative recovery [evaluated with length of post anesthesia care unit (PACU) stay, time of first exhaust and defecation after surgery and length of hospital stay] and postoperative inflammation conditions [evaluated with serum concentration of interleukin (IL)-1β and IL-6 at 1 d and 3 d after surgery]. Results: The incidence of moderate to severe pain in group D 1 h after surgery was 13.3% (8/60), lower than 30.0% (18/60) of group C (P<0.05). The incidence of rescue analgesia in group D at 1 h and 1 d after surgery were 13.3% (8/60) and 4.2% (5/120), respectively, lower than 30.0% (18/60) and 12.5% (15/120) of group C (both P<0.05). The IL-1β level in group D was (4.1±1.8)ng/L at 1 d after surgery, which was lower than (4.9±2.6) ng/L of group C (P=0.048). The IL-6 level in group D was (2.0±0.7)ng/L at 3 d after surgery, which was lower than (2.4±1.1) ng/L of group C (P=0.018). There was no significant difference in the doses of sufentanil in analgesic pumps, intraoperative SRS score, incidence of neuromuscular block residue, time spent in PACU, time of first exhaust and defecation after surgery, incidence of nausea and vomiting, and length of hospitalization between the two groups (all P>0.05). Conclusion: DNMB combined with low pneumoperitoneum pressure anesthesia strategy alleviates the early-stage pain in patients after laparoscopic colorectal surgery.

[Clinical value of arterial stiffness assessment on risk prediction of vascular stiffness in the octogenarian elderly]

Objective: This study aimed to analyze clinical factors related to arterial stiffening and establish a risk prediction nomogram of arterial stiffening in the octogenarian(≥80 years). Methods: This study was a retrospective cross-sectional study, which enrolled the octogenarian elderly who underwent physical examination and secondary prevention intervention in the outpatient department of Chinese People's Liberation Army General Hospital from April 2022 to August 2022. Clinical data including demographics, biochemical indicators and medical history were collected. Brachial-ankle pulse wave velocity (baPWV) was detected during the clinical visit. Participants were divided into the control group (baPWV≤1 800 cm/s) and vascular sclerosis group (baPWV>1 800 cm/s). The risk factors of arterial stiffness were analyzed by univariate and logistic regression analysis, and the nomogram model was constructed by R programming language. The predictive effect of the nomogram model was evaluated by the receiver operating characteristic curve (ROC). Results: The median age of the 525 participants was 87.0 (82.0, 92.0) years, 504 (96.0%) were male, 82 in the control group, 443 in the vascular sclerosis group. The baPWV, age, systolic blood pressure, mean arterial pressure and diastolic blood pressure were significantly lower in the control group than those in the vascular sclerosis group (all P<0.05). Logistic regression analysis showed that high-density lipoprotein cholesterol, alanine aminotransferase and amylase were protective factors, and alkaline phosphatase and creatinine were risk factors of arterial stiffening (all P<0.05). The combined nomogram model scores including age, mean arterial pressure and the above five laboratory indicators indicated that mean arterial pressure and serum creatinine levels were strongly correlated with vascular sclerosis. The ROC curve suggested that the nomogram model had good prediction ability. Conclusions: Age, mean arterial pressure, high-density lipoprotein cholesterol, alanine aminotransferase, alkaline phosphatase, amylase and creatinine are independently determinants for increased vascular stiffness. The combined prediction model in this study can provide reference for individualized clinical risk prediction of vascular sclerosis in the octogenarian elderly.

[Enterostomy based on abdominal wall tension and fascial locking: a theory of preventing stoma complications and parahernia]

No consensus on standardized technique of enterostomy creation has been made meanwhile high heterogeneity of surgical procedure exists in 'stoma creation' chapters of textbooks or atlases of colorectal surgery. The present article reviews the anatomy of tendinous aponeurotic fibers which is crucial for abdominal wall tension and integrity. Through empirical practice we hypothesize a procedure of enterostomy creation basied on abdominal wall tension plus anchor suture for fascia fixation which could theoretically decrease short-term stoma complication rates and long-term parastomal hernia rates. Surgical techniques are as followed: (1) preoperative stoma site mark for de-functioning ileostomy should be positioned at the lateral border of rectus abdominis muscle (RAM) to decrease the difficulty of stoma reversal and for permanent colostomy should be placed overlying the RAM to promote adhesion; (2)Optimal circular removal or lineal opening of skin, and avoid dissection of subcutaneous tissue; (3) Lineal dissection of natural strong fascia (rectus sheath) at stoma site and blunt separation of muscular fibers. The tunnel of the fascia should be made with appropriate size without undue tension. To prevent the formation of dead space, additional suturing at fascia layer is unnecessary. (4) Anchor suture for fascia fixation at two ends of fascia opening could be considered to avoid delayed fascia disruption and parastomal hernia. (5) After pull-through of ileum or colon loop, 4-8 interrupted seromuscular sutures could be placed to attach loop to skin. For ileostomy, self-eversion of mucosa can be successful in vast majority of cases and a Brooke ileostomy is not necessary. The efficacy and safety of this procedure should be tested in future trials.

[Double-edged sword of opioids in the treatment of cancer pain: hyperalgesia]

Hyperalgesia is an occult complication during the treatment of cancer pain, not only related to opioids, but also pertaining to the tumor itself and cancer therapeutic drugs. Yet it is often ignored by clinicians. Patients with cancer pain who were treated with opioids often have sensory abnormalities presented with reduced pain threshold and increased sensitivity to nociceptive stimuli. This phenomenon is clinically called opioid-induced hyperalgesia (OIH). However, due to the complexity of pathogenesis and the lack of clinical diagnostic criteria, the pain management of cancer patients is still facing great challenges. Therefore, this article focuses on the clinical diagnosis, pathogenesis, prevention and treatment of hyperalgesia related to cancer pain treatment, in order to provide a basis for optimal use of opioids in the future.

[Effects of myocardial fibrosis on ischemic preconditioning against myocardial ischemia-reperfusion injury in type 2 diabetic rats]

Objective: To assess whether myocardial fibrosis affects the protective efficiency of ischemic preconditioning (IPC) against myocardial ischemia/reperfusion injury (MIRI) in type 2 diabetic rats. Methods: Type 2 diabetic rat model was established. Fifty-four normal and 54 diabetic spragus-dawley (SD) rats were equally divided into 6 groups (n=18) using the random number table method: (1) Control group (C group); (2) Ischemia reperfusion injury (IRI) control group (IRI group); (3) IPC group; (4) Diabetic control group (DC group); (5) Diabetic IRI group (DIRI group); (6) Diabetic IPC group (DIPC group). After the reperfusion, blood samples were obtained for measuring serum concentrations of creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) using enzyme-linked immunosorbent assay (ELISA). The myocardial infarction size (IS) was assessed by double staining method with Evan's blue and Triphenyl tetrazolium chloride (TTC), and the myocardial collagen volume fraction (CVF) and perivascular collagen area (PVCA) were assessed by Masson staining. Results: A stable and effective rat model with long-term diabetes was established in the current study. Compared with the normal rat groups, the CVF and PVCA significantly increased (all P<0.05) in the diabetic rat groups. The levels of CK-MB, cTnI and IS in the IPC group were (6.6±0.8) ng/ml, (0.5±0.1) ng/ml and (25.1±4.7) %, which showed significant decrease compared with (12.3±1.1) ng/ml, (1.2±0.3) ng/ml and (52.3±8.1) % in IRI group (all P<0.05). Among the diabetic rat groups, the CK-MB and cTnI levels in DIPC group were (11.5±0.9) and (1.1±0.1) ng/ml, apparently lower than the levels of (16.6±2.2) and (1.4±0.3) ng/ml in the DIRI group (both P<0.05). Compared with the IPC group, the IS, CK-MB and cTnI levels significantly increased in the DIPC group (all P<0.05). Conclusion: Myocardial fibrosis exists in rats with long-term type 2 diabetes, which weakens the protective effect of IPC on diabetes MIRI.

The effects of age on neural correlates of recognition memory: An fMRI study

Studies examining the effects of age on the neural correlates of recognition memory have yielded mixed results. In the present study, we employed a modified remember-know paradigm to compare the fMRI correlates of recollection and familiarity in samples of healthy young and older adults. After studying a series of words, participants underwent fMRI scanning during a test phase in which they responded "remember" to a test word if any qualitative information could be recollected about the study event. When recollection failed, participants signaled how confident they were that the test item had been studied. Young and older adults demonstrated statistically equivalent estimates of recollection and familiarity strength, while recognition memory accuracy was significantly lower in the older adults. Robust, age-invariant fMRI effects were evident in two sets of a priori defined brain regions consistently reported in prior studies to be sensitive to recollection and familiarity respectively. In addition, the magnitudes of 'familiarity-attenuation effects' in perirhinal cortex demonstrated age-invariant correlations with estimates of familiarity strength and memory accuracy, replicating prior findings. Together, the present findings add to the evidence that the neural correlates of recognition memory are largely stable across much of the healthy human adult lifespan.

[Perirectal fascial anatomy and pelvic autonomic nerve preservation during the transanal total mesorectal excision]

The difficulty of transanal total mesorectal excision (TME) is to find the correct dissection plane of perirectal space. As a complex new surgical procedure, the fascial anatomic landmarks of transanal approach operation are more likely to be ignored. It is often found that dissection plane is false after the secondary injury occurs during the operation, which results in the damage of pelvic autonomic nerves. Meanwhile, the mesorectum is easily damaged if the dissection plane is too close to the rectum. Thus, the safety of oncologic outcomes could be limited by difficulty achieving adequate TME quality. The promotion and development of the theory of perirectal fascial anatomy provides a new thought for researchers to design a precise approach for transanal endoscopic surgery. Transanal total mesorectal excision based on fascial anatomy offers a solution to identify the transanal anatomic landmarks precisely and achieves pelvic autonomic nerve preservation. In this paper, the authors focus on the surgical experience of transanal total mesorectal excision based on the theory of perirectal fascial anatomy, and discuss the feature of perirectal fascial anatomy dissection and technique of pelvic autonomic nerve preservation during transanal approach operation.

Separation of item and context in item-method directed forgetting

Contextual information plays a critical role in directed forgetting (DF) of lists of items, whereas DF of individual items has been primarily associated with item-level processing. This study was designed to investigate whether context processing also contributes to the forgetting of individual items. Participants first viewed a series of words, with task-irrelevant scene images (used as "context tags") interspersed between them. Later, these words reappeared without the scenes and were followed by an instruction to remember or forget that word. Multivariate pattern analyses of fMRI data revealed that the reactivation of context information associated with the studied words (i.e., scene-related activity) was greater whereas the item-related information diminished after a forget instruction compared to a remember instruction. Critically, we found the magnitude of the separation between item information and context information predicted successful forgetting. These results suggest that the unbinding of an item from its context may support the intention to forget, and more generally they establish that contextual processing indeed contributes to item-method DF.

[Prognosis analysis of 112 cases with Japanese encephalitis in adults]

Objective: To analyze the improvement of clinical symptoms and recovery of neurological function in adult Japanese encephalitis, and study the prognostic factors. Methods: Follow-up was conducted for 112 hospitalized patients with Japanese encephalitis (JE) in adults at the Department of Neurology of three hospitals in Gansu province from July to October 2016, from July to October 2017, 6 months and 1 year after onset, respectively. The neurological functional recovery was evaluated by modified Ranking Scale (mRS).The influencing factors were analyzed by logistic regression model. Results: Among the 112 adult patients with JE after 1year follow-up, 57% (64/112) were completely recovered (mRS score=0), and 14%(16/112) had mild neurological dysfunction (mRS score=1 or 2 points), 20% (22/112) had moderate to severe neurological dysfunction (mRS score 3 to 5), and 9% (10/112) died. In 102 survivors, decreased consciousness were fully recovered (100%), 75% of the mental and behavior disorders, 64% of cognitive/memory impairment, 71% of language function disorder, 61% of paralysis, 73% of extrapyramidal symptoms were fully recovered, and 92% of the seizures were controlled. Comparison of clinical data of initial on-set between good prognosis group (mRS score≤2, 80 cases) and poor prognosis group (mRS score>2, 32 cases) showed that initial clinical manifestation with seizures, consciousness (GCS score), cerebrospinal fluid pressure, and lesion of MRI involved in midbrain had statistically significant differences (all P<0.05) . Multivariate analysis demonstrated that cerebrospinal fluid (CSF) pressure>250 mmH(2)O and lesion of midbrain in MRI were independent risk factors of poor prognosis in adult patients with JE. Conclusion: JE is an acute and infectious viral encephalitis of the central nervous system with high disability and mortality. Most patients were completely recovered, and some had neurological sequelae. CSF pressure>250 mmH(2)O and lesion of midbrain in MRI are independent risk factors for poor prognosis.

Effects of age on across-participant variability of cortical reinstatement effects

Using functional magnetic resonance imaging data, we assessed whether across-participant variability of content-selective retrieval-related neural activity differs with age. We addressed this question by employing across-participant multi-voxel pattern analysis (MVPA), predicting that increasing age would be associated with reduced variability of retrieval-related cortical reinstatement across participants. During study, 24 young and 24 older participants viewed objects and concrete words. Test items comprised studied words, names of studied objects, and unstudied words. Participants judged whether the items were recollected, familiar, or new by making 'Remember', 'Know' and 'New' responses, respectively. MVPA was conducted on each region belonging to the 'core recollection network', dorsolateral prefrontal cortex, and a previously identified content-selective voxel set. A leave-one-participant-out classification approach was employed whereby a classifier was trained on a subset of participants and tested on the data from a yoked pair of held-out participants. Classifiers were trained on the study phase data to discriminate the study trials as a function of content (picture or word). The classifiers were then applied to the test phase data to discriminate studied test words according to their study condition. In all of the examined regions, classifier performance demonstrated little or no sensitivity to age and, for the test data, was robustly above chance. Thus, there was little evidence to support the hypothesis that across-participant variability of retrieval-related cortical reinstatement differs with age. The findings extend prior evidence by demonstrating that content-selective cortical reinstatement is sufficiently invariant to support across-participant multi-voxel classification across the healthy adult lifespan.

Rapid Microbiology Screening in Pharmaceutical Workflows

Recently advances in miniaturization and automation have been utilized to rapidly decrease the time to result for microbiology testing in the clinic. These advances have been made due to the limitations of conventional culture-based microbiology methods, including agar plate and microbroth dilution, which have long turnaround times and require physicians to treat patients empirically with antibiotics before test results are available. Currently, there exist similar limitations in pharmaceutical sterility and bioburden testing, where the long turnaround times associated with standard microbiology testing drive costly inefficiencies in workflows. These include the time lag associated with sterility screening within drug production lines and the warehousing cost and time delays within supply chains during product testing. Herein, we demonstrate a proof-of-concept combination of a rapid microfluidic assay and an efficient cell filtration process that enables a path toward integrating rapid tests directly into pharmaceutical microbiological screening workflows. We demonstrate separation and detection of Escherichia coli directly captured and analyzed from a mammalian (i.e., CHO) cell culture with a 3.0 h incubation. The demonstration is performed using a membrane filtration module that is compatible with sampling from bioreactors, enabling in-line sampling and process monitoring.

Fisetin Exerts Antioxidant and Neuroprotective Effects in Multiple Mutant hSOD1 Models of Amyotrophic Lateral Sclerosis by Activating ERK

Oxidative stress exhibits a central role in the course of amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disease commonly found to include a copper/zinc superoxide dismutase (SOD1) gene mutation. Fisetin, a natural antioxidant, has shown benefits in varied neurodegenerative diseases. The possible effect of fisetin in ALS has not been clarified as of yet. We investigated whether fisetin affected mutant hSOD1 ALS models. Three different hSOD1-related mutant models were used: Drosophila expressing mutant hSOD1^G85R, hSOD1^G93A NSC34 cells, and transgenic mice. Fisetin treatment provided neuroprotection as demonstrated by an improved survival rate, attenuated motor impairment, reduced ROS damage and regulated redox homeostasis compared with those in controls. Furthermore, fisetin increased the expression of phosphorylated ERK and upregulated antioxidant factors, which were reversed by MEK/ERK inhibition. Finally, fisetin reduced the levels of both mutant and wild-type hSOD1 in vivo and in vitro, as well as the levels of detergent-insoluble hSOD1 proteins. The results indicate that fisetin protects cells from ROS damage and improves the pathological behaviors caused by oxidative stress in disease models related to SOD1 gene mutations probably by activating ERK, thereby providing a potential treatment for ALS.

Mobile nucleic acid amplification testing (mobiNAAT) for Chlamydia trachomatis screening in hospital emergency department settings

Management of curable sexually-transmitted infections (STI) such as Chlamydia can be revolutionized by highly sensitive nucleic acid testing that is deployable at the point-of-care (POC). Here we report the development of a mobile nucleic acid amplification testing (mobiNAAT) platform utilizing a mobile phone and droplet magnetofluidics to deliver NAAT in a portable and accessible format. By using magnetic particles as a mobile substrate for nucleic acid capture and transport, fluid handling is reduced to particle translocation on a simple magnetofluidic cartridge assembled with reagents for nucleic acid purification and amplification. A mobile phone user interface operating in tandem with a portable Bluetooth-enabled cartridge-processing unit facilitates process integration. We tested 30 potentially Chlamydia trachomatis (CT)-infected patients in a hospital emergency department and confirmed that mobiNAAT showed 100% concordance with laboratory-based NAAT. Concurrent evaluation by a nontechnical study coordinator who received brief training via an embedded mobile app module demonstrated ease of use and reproducibility of the platform. This work demonstrates the potential of mobile nucleic acid testing in bridging the diagnostic gap between centralized laboratories and hospital emergency departments.

Independent contributions of fMRI familiarity and novelty effects to recognition memory and their stability across the adult lifespan

The impact of age on the neural correlates of familiarity-driven recognition memory has received relatively little attention. Here, the relationships between age, the neural correlates of familiarity, and memory performance were investigated using an associative recognition test in young, middle-aged and older participants. Test items comprised studied, rearranged (items studied on different trials) and new word pairs. fMRI 'familiarity effects' were operationalized as greater activity for studied test pairs incorrectly identified as 'rearranged' than for correctly rejected new pairs. The reverse contrast was employed to identify 'novelty' effects. Estimates of familiarity strength were slightly but significantly lower for the older relative to the younger group. With the exception of one region in dorsal medial prefrontal cortex, fMRI familiarity effects (which were identified in medial and lateral parietal cortex, dorsal medial and left lateral prefrontal cortex, and bilateral caudate among other regions) did not differ significantly with age. Age-invariant 'novelty effects' were identified in the anterior hippocampus and the perirhinal cortex. When entered into the same regression model, familiarity and novelty effects independently predicted familiarity strength across participants, suggesting that the two classes of memory effect reflect functionally distinct mnemonic processes. It is concluded that the neural correlates of familiarity-based memory judgments, and their relationship with familiarity strength, are largely stable across much of the healthy adult lifespan.

Decoding the content of recollection within the core recollection network and beyond

Recollection - retrieval of qualitative information about a past event - is associated with enhanced neural activity in a consistent set of neural regions (the 'core recollection network') seemingly regardless of the nature of the recollected content. Here, we employed multi-voxel pattern analysis (MVPA) to assess whether retrieval-related functional magnetic resonance imaging (fMRI) activity in core recollection regions - including the hippocampus, angular gyrus, medial prefrontal cortex, retrosplenial/posterior cingulate cortex, and middle temporal gyrus - contain information about studied content and thus demonstrate retrieval-related 'reinstatement' effects. During study, participants viewed objects and concrete words that were subjected to different encoding tasks. Test items included studied words, the names of studied objects, or unstudied words. Participants judged whether the items were recollected, familiar, or new by making 'remember', 'know', and 'new' responses, respectively. The study history of remembered test items could be reliably decoded using MVPA in most regions, as well as from the dorsolateral prefrontal cortex, a region where univariate recollection effects could not be detected. The findings add to evidence that members of the core recollection network, as well as at least one neural region where mean signal is insensitive to recollection success, carry information about recollected content. Importantly, the study history of recognized items endorsed with a 'know' response could be decoded with equal accuracy. The results thus demonstrate a striking dissociation between mean signal and multi-voxel indices of recollection. Moreover, they converge with prior findings in suggesting that, as it is operationalized by classification-based MVPA, reinstatement is not uniquely a signature of recollection.

Characterization of the Microbial Communities in the Ant Lion Euroleon coreanus (Okamoto) (Neuroptera: Myrmeleontidae)

Euroleon coreanus (Okamoto) is widely distributed in China, and the larval stage can be treated as traditional Chinese medicine. However, the host-bacterium relationship remains unexplored, as there is a lack of knowledge on the microbial community of ant lions. Hence, in the current study, we explored the microbial community of the larval ant lion E. coreanus using Illumina MiSeq sequencing. Results indicated that a total of 10 phyla, 126 genera, and 145 species were characterized from the second instars of E. coreanus, and most of the microbes were classified in the phylum Proteobacteria. Cronobacter muytjensii was the most abundant species characterized in the whole body and gut of E. coreanus, and the unclassified species in the genera Brevundimonas and Lactobacillus were relatively more abundant in the head and carcass. In addition, no Wolbachia-like bacteria were detected, whereas bacteria like Francisella tularensis subsp. Holarctica OSU18 and unclassified Rickettsiella were first identified in ant lion E. coreanus.

The relationships between age, associative memory performance, and the neural correlates of successful associative memory encoding

Using functional magnetic resonance imaging, subsequent memory effects (greater activity for later remembered than later forgotten study items) predictive of associative encoding were compared across samples of young, middle-aged, and older adults (total N = 136). During scanning, participants studied visually presented word pairs. In a later test phase, they discriminated between studied pairs, "rearranged" pairs (items studied on different trials), and new pairs. Subsequent memory effects were identified by contrasting activity elicited by study pairs that went on to be correctly judged intact or incorrectly judged rearranged. Effects in the hippocampus were age-invariant and positively correlated across participants with associative memory performance. Subsequent memory effects in the right inferior frontal gyrus (IFG) were greater in the older than the young group. In older participants only, both left and, in contrast to prior reports, right IFG subsequent memory effects correlated positively with memory performance. We suggest that the IFG is especially vulnerable to age-related decline in functional integrity and that the relationship between encoding-related activity in right IFG and memory performance depends on the experimental context.

Abscess formation in ovarian endometriomas after failure of mifepristone-induced abortion

OBJECTIVE

To report a case of abscess formation in bilateral ovarian endometriomas after failure of mifepristone-induced abortion.

CASE REPORT

A-36-year-old multiparous woman with bilateral ovarian endometriomas conceived spontaneously and received mifepristone to induce an abortion at 35 days' gestation. Fever and lower abdominal pain occurred 28 days after the abortion. The patient then underwent surgical curettage for an incomplete abortion complicated by endometritis. Her symptoms and signs became aggravated, and computed tomography showed a large ovarian abscess. She underwent laparoscopic drainage of the abscess plus the enucleation of the ovarian endometriomas, and received intravenous antibiotic treatment. She resumed menstruation one month later and was doing well at the 11-month follow-up.

CONCLUSION

This case demonstrates the importance of combining antibiotic therapy with mifepristone to induce abortions in women with known ovarian endometriomas.

The Effects of Age on the Neural Correlates of Recollection Success, Recollection-Related Cortical Reinstatement, and Post-Retrieval Monitoring

Functional magnetic resonance imaging (fMRI) was used to investigate whether age-related differences in episodic memory performance are accompanied by a reduction in the specificity of recollected information. We addressed this question by comparing recollection-related cortical reinstatement in young and older adults. At study, subjects viewed objects and concrete words, making 1 of 2 different semantic judgments depending on the study material. Test items were words that corresponded to studied words or the names of studied objects. Subjects indicated whether each test item was recollected, familiar, or novel. Reinstatement of information differentiating the encoding tasks was quantified both with a univariate analysis of the fMRI signal and with a multivoxel pattern analysis, using a classifier that had been trained to discriminate between the 2 classes of study episode. The results of these analyses converged to suggest that reinstatement did not differ according to age. Thus, there was no evidence that specificity of recollected information was reduced in older individuals. Additionally, there were no age effects in the magnitude of recollection-related modulations in regional activity or in the neural correlates of post-retrieval monitoring. Taken together, the findings suggest that the neural mechanisms engaged during successful episodic retrieval can remain stable with advancing age.

Cortical reinstatement and the confidence and accuracy of source memory

Cortical reinstatement refers to the overlap between neural activity elicited during the encoding and the subsequent retrieval of an episode, and is held to reflect retrieved mnemonic content. Previous findings have demonstrated that reinstatement effects reflect the quality of retrieved episodic information as this is operationalized by the accuracy of source memory judgments. The present functional magnetic resonance imaging (fMRI) study investigated whether reinstatement-related activity also co-varies with the confidence of accurate source judgments. Participants studied pictures of objects along with their visual or spoken names. At test, they first discriminated between studied and unstudied pictures and then, for each picture judged as studied, they also judged whether it had been paired with a visual or auditory name, using a three-point confidence scale. Accuracy of source memory judgments- and hence the quality of the source-specifying information--was greater for high than for low confidence judgments. Modality-selective retrieval-related activity (reinstatement effects) also co-varied with the confidence of the corresponding source memory judgment. The findings indicate that the quality of the information supporting accurate judgments of source memory is indexed by the relative magnitude of content-selective, retrieval-related neural activity.

Quantum dots in diagnostics and detection: principles and paradigms

Quantum dots are semiconductor nanocrystals that exhibit exceptional optical and electrical behaviors not found in their bulk counterparts. Following seminal work in the development of water-soluble quantum dots in the late 1990's, researchers have sought to develop interesting and novel ways of exploiting the extraordinary properties of quantum dots for biomedical applications. Since that time, over 10,000 articles have been published related to the use of quantum dots in biomedicine, many of which regard their use in detection and diagnostic bioassays. This review presents a didactic overview of fundamental physical phenomena associated with quantum dots and paradigm examples of how these phenomena can and have been readily exploited for manifold uses in nanobiotechnology with a specific focus on their implementation in in vitro diagnostic assays and biodetection.

Effects of age on negative subsequent memory effects associated with the encoding of item and item-context information

It has consistently been reported that "negative" subsequent memory effects--lower study activity for later remembered than later forgotten items--are attenuated in older individuals. The present functional magnetic resonance imaging study investigated whether these findings extend to subsequent memory effects associated with successful encoding of item-context information. Older (n = 25) and young (n = 17) subjects were scanned while making 1 of 2 encoding judgments on a series of pictures. Memory was assessed for the study item and, for items judged old, the item's encoding task. Both memory judgments were made using confidence ratings, permitting item and source memory strength to be unconfounded and source confidence to be equated across age groups. Replicating prior findings, negative item effects in regions of the default mode network in young subjects were reversed in older subjects. Negative source effects, however, were invariant with respect to age and, in both age groups, the magnitude of the effects correlated with source memory performance. It is concluded that negative item effects do not reflect processes necessary for the successful encoding of item-context associations in older subjects. Negative source effects, in contrast, appear to reflect the engagement of processes that are equally important for successful episodic encoding in older and younger individuals.

Mesoporous SnO2@carbon core-shell nanostructures with superior electrochemical performance for lithium ion batteries

SnO2@carbon nanostructure composites are prepared by a simple hydrothermal method. The composite exhibits unique structure, which consists of a mesoporous SnO2 core assembled of very small nanoparticles and a carbon shell with 10 nm thickness. The mesoporous SnO2@carbon core-shell nanostructures manifest superior electrochemical performance as an anode material for lithium ion batteries. The reversible specific capacity of the composite is about 908 mAh g(-1) for the first cycle and it can retain about 680 mAh g(-1) after 40 charge/discharge cycles at a current density of 0.3 C. Moreover, it shows excellent rate capability even at the high rate of 4.5 C. The enhanced performance was attributed to the mesoporous structure and a suitable carbon coating.

Effects of age on the neural correlates of familiarity as indexed by ERPs

ERPs were recorded from samples of young (18-29 years) and older (63-77 years) participants while they performed a modified "remember-know" recognition memory test. ERP correlates of familiarity-driven recognition were obtained by contrasting the waveforms elicited by unrecollected test items accorded "confident old" and "confident new" judgments. Correlates of recollection were identified by contrasting the ERPs elicited by items accorded "remember" and confident old judgments. Behavioral analyses revealed lower estimates of both recollection and familiarity in older participants than in young participants. The putative ERP correlate of recollection-the "left parietal old-new effect"-was evident in both age groups, although it was slightly but significantly smaller in the older sample. By contrast, the putative ERP correlate of familiarity-the "midfrontal old-new effect"-could be identified in young participants only. This age-related difference in the sensitivity of ERPs to familiarity was also evident in subgroups of young and older participants, in whom familiarity-based recognition performance was equivalent. Thus, the inability to detect a reliable midfrontal old-new effect in older participants was not a consequence of an age-related decline in the strength of familiarity. These findings raise the possibility that familiarity-based recognition memory depends upon qualitatively different memory signals in older and young adults.

The effects of age, memory performance, and callosal integrity on the neural correlates of successful associative encoding

This functional magnetic resonance imaging study investigated the relationship between the neural correlates of associative memory encoding, callosal integrity, and memory performance in older adults. Thirty-six older and 18 young subjects were scanned while making relational judgments on word pairs. Neural correlates of successful encoding (subsequent memory effects) were identified by contrasting the activity elicited by study pairs that were correctly identified as having been studied together with the activity elicited by pairs wrongly judged to have come from different study trials. Subsequent memory effects common to the 2 age groups were identified in several regions, including left inferior frontal gyrus and bilateral hippocampus. Negative effects (greater activity for forgotten than for remembered items) in default network regions in young subjects were reversed in the older group, and the amount of reversal correlated negatively with memory performance. Additionally, older subjects' subsequent memory effects in right frontal cortex correlated positively with anterior callosal integrity and negatively with memory performance. It is suggested that recruitment of right frontal cortex during verbal memory encoding may reflect the engagement of processes that compensate only partially for age-related neural degradation.

Electric-dipole transitions between group-III acceptor states in uniaxially compressed Ge

We study the electric-dipole transitions between group-III acceptor states in Ge under stress along the [001] crystallographic direction in the effective mass approximation. We systematically investigate the cases of zero stress, infinitesimal stress, and finite stress including the low-stress and the high-stress regions. Our results show quantitative agreement with experimental data at zero stress and at infinitesimal stress. The relative intensities of infinitesimal-stress-induced components of transitions from the 1Γ(8)(+) state to the nΓ(8)(-) states do not correlate significantly with the species of acceptors except for the transition to the 1Γ(8)(-) state. The oscillator strengths of some transitions are susceptible to the stress in the low-stress region (<0.3 kbar), and could be zero at a specific stress. The behaviours of the stress dependence of oscillator strengths for different transition lines are explained in terms of the compositions of the wavefunctions and the dipole matrix elements. In the high-stress region (> or approximately equal3 kbar), the ground state is s-like, and only the transitions to the p-like states can have non-negligible oscillator strengths. The photon absorbed (emitted) and associated with each electric-dipole transition between the s-like and the p-like states is polarized either parallel or perpendicular to the stress direction. We also calculate the absorption spectra for Ge:Ga at liquid-helium temperature. The results are in good agreement with experiment.

Quantum dots in molecular detection of disease

The unique photophysical properties of semiconductor quantum dots (QDs) have made them ideal for use as spectral labels and luminescent probes. In this review, applications are presented in which QDs function as active participants in nanoscale biosensor assemblies, where replacing traditional molecular fluorophores results in improved assay performance. Specific focus is on disease detection with applications including multiplexed target detection, mutation detection by coincidence analysis and QD-based FRET reporters for miRNA detection and DNA methylation analysis.

Rainbow trout interleukin-2: cloning, expression and bioactivity analysis

In this study the rainbow trout (Oncorhynchus mykiss) interleukin-2 (IL-2) cDNA has been cloned, and its expression and bioactivity analysed in head kidney leucocytes. The IL-2 precursor encoded an open reading frame of 429 bp, that translates into a predicted protein of 142 aa, with a 20 aa signal peptide. The trout IL-2 had moderate protein homology (30.9% identity/48.3% similarity) with Fugu IL-2, the only IL-2 homologue identified in fish to date, with lower homology to avian (17.8% identity/23.2% similarity) and mammalian (34.2 identity/46.5% similarity) IL-2s. IL-2 expression was induced by the T cell mitogen PHA and by the mixed leucocyte reaction, where leucocytes from pairs of fish were cultured together for four days. Expression was also induced in vivo during bacterial (Yersinia ruckeri) infection. The Escherichia coli produced recombinant IL-2 was shown to increase the expression of two transcription factors, STAT5 and Blimp-1, known to be involved in IL-2 signalling in mammals, as well as IFN-gamma, gIP and IL-2 itself. The potential signalling pathways involved and possible use as an adjuvant for fish vaccines are discussed.

Electronic structure analysis for group III acceptors in Ge under stress considering screening effect and central-cell correction

We study theoretically the electronic structures of various group III acceptors in Ge under [001] stress, based on the effective-mass theory with a semi-empirical impurity potential which considers the q-dependent screening and the central-cell correction. An assignment is made for inter-level transition lines which were previously ignored or incorrectly assigned. In addition, our calculation can resolve crowding levels of final states of transition lines which have not been resolved by experimental techniques. The stress effect on the electronic structure can be understood by connecting with the composition of the states. Our results show that the binding energies decrease rapidly with the stress in the low-stress region, and for even-parity states they exhibit remarkable asymmetry in the stress dependence due to the large difference between the heavy-hole and the light-hole compositions. The acceptor states asymptotically approach a pure heavy-hole or light-hole state under high stress. In the limiting case of high stress, extra degeneracy appears. The central-cell correction may cause a significant chemical shift for even-parity states of nonisocoric acceptors. We also complete the assignment of the four line components into which the B line splits under stress. The newly assigned stress-dependent transition energies show excellent agreement with the experimental data for low stress. A justification is made for the applicability of our calculation scheme to the case of high stress.

Effects of advanced aging on the neural correlates of successful recognition memory

Functional neuroimaging studies have reported that the neural correlates of retrieval success (old>new effects) are larger and more widespread in older than in young adults. In the present study we investigated whether this pattern of age-related 'over-recruitment' continues into advanced age. Using functional magnetic resonance imaging (fMRI), retrieval-related activity from two groups (N=18 per group) of older adults aged 84-96 years ('old-old') and 64-77 years ('young-old') was contrasted. Subjects studied a series of pictures, half of which were presented once, and half twice. At test, subjects indicated whether each presented picture was old or new. Recognition performance of the old-old subjects for twice-studied items was equivalent to that of the young-old subjects for once-studied items. Old>new effects common to the two groups were identified in several cortical regions, including medial and lateral parietal and prefrontal cortex. There were no regions where these effects were of greater magnitude in the old-old group, and thus no evidence of over-recruitment in this group relative to the young-old individuals. In one region of medial parietal cortex, effects were greater (and only significant) in the young-old group. The failure to find evidence of over-recruitment in the old-old subjects relative to the young-old group, despite their markedly poorer cognitive performance, suggests that age-related over-recruitment effects plateau in advanced age. The findings for the medial parietal cortex underscore the sensitivity of this cortical region to increasing age.

Coupling confocal fluorescence detection and recirculating microfluidic control for single particle analysis in discrete nanoliter volumes

The recent proliferation of platforms designed to handle arrays of nano- and picolitre volumes is in response to the need to perform biological assays on discrete entities, such as single cells. However, a critical challenge associated with this trend for in vitro compartmentalization is the need for highly sensitive, yet low-volume detection platforms. In this paper, we coupled confocal fluorescence detection with recirculating microfluidic control to perform single particle DNA assays within five nL chambers. The performance of this low-volume assay was shown to match that of traditional single molecule detection platforms. However, volume requirements per measurement were nearly 3 orders of magnitude less than conventional systems, enabling future integration with lab-on-a-chip systems that require discrete or digitalized sample processing.

Outcome of antenatally diagnosed cardiac rhabdomyoma: case series and a meta-analysis

OBJECTIVES

Rhabdomyoma, the most common primary fetal cardiac tumor, is often associated with tuberous sclerosis (TS). We aimed to evaluate outcome in cases diagnosed with fetal cardiac rhabdomyoma.

METHODS

This study presents 11 cases with fetal cardiac rhabdomyoma. In addition, all relevant published cases of antenatally diagnosed cardiac rhabdomyoma since 1982 were identified from MEDLINE. We evaluated the following risk factors associated with clinical impact and perinatal outcome: family history of TS, gestational age at diagnosis, tumor size, site and number of tumors, tumor progression, and associated intracardiac and extracardiac anomalies.

RESULTS

In this meta-analysis, 138 cases, including nine newly added by us, were categorized into Group A (107 live babies) and Group B (16 neonatal deaths and 15 intrauterine fetal deaths). Univariate analysis showed that large cardiac tumors (P < 0.0001), fetal dysrhythmia (P < 0.0001) and hydrops (P < 0.0001) were strong predictors of neonatal outcome. Tumor size >or= 20 mm (relative risk (RR), 20.6; 95% CI, 2.2-195.9; P = 0.009) and fetal dysrhythmia (RR, 13.6; 95% CI, 2.9-62.3; P = 0.001) were significantly associated with neonatal morbidity. TS, present in 85/133 (63.9%) cases, was significantly associated with multiple cardiac tumors (P < 0.0001) and family history of TS (P = 0.02).

CONCLUSIONS

Large tumor size and hydrops are significantly associated with poor neonatal outcome, whereas family history of TS and multiple fetal cardiac tumors are associated with TS. Any sonographic detection of a fetal cardiac tumor should warrant further investigation for the possible presence of associated disorders.

Substrate-free growth, characterization and growth mechanism of ZnO nanorod close-packed arrays

ZnO nanorod close-packed arrays are successfully fabricated in a substrate-free manner by a citric acid assisted annealing process at a low growth temperature of 400 °C. Each nanorod of ZnO nanorod close-packed arrays grows along the [0001] direction and is single crystalline with an average diameter of 50 nm, and an average length of 0.5 µm. The aspect ratio is 10. The ZnO nanorod close-packed arrays show a strong exciton absorption peak at 372 nm in UV-visible absorption spectra, exhibiting a blue-shift relative to the bulk exciton absorption (387 nm). Finally, a new growth mechanism is proposed for the substrate-free preparation of ZnO nanorod close-packed arrays by a citric acid assisted annealing process.

Open Access Series of Imaging Studies (OASIS): cross-sectional MRI data in young, middle aged, nondemented, and demented older adults

The Open Access Series of Imaging Studies is a series of magnetic resonance imaging data sets that is publicly available for study and analysis. The initial data set consists of a cross-sectional collection of 416 subjects aged 18 to 96 years. One hundred of the included subjects older than 60 years have been clinically diagnosed with very mild to moderate Alzheimer's disease. The subjects are all right-handed and include both men and women. For each subject, three or four individual T1-weighted magnetic resonance imaging scans obtained in single imaging sessions are included. Multiple within-session acquisitions provide extremely high contrast-to-noise ratio, making the data amenable to a wide range of analytic approaches including automated computational analysis. Additionally, a reliability data set is included containing 20 subjects without dementia imaged on a subsequent visit within 90 days of their initial session. Automated calculation of whole-brain volume and estimated total intracranial volume are presented to demonstrate use of the data for measuring differences associated with normal aging and Alzheimer's disease.

Shot noise with interaction effects in single-walled carbon nanotubes

We have measured shot noise in single-walled carbon nanotubes with good contacts at 4.2 K at low frequencies (f=600-850 MHz). We find a strong modulation of shot noise over the Fabry-Perot pattern; in terms of the differential Fano factor the variation ranges over 0.4-1.2. The shot noise variation, in combination with differential conductance, is analyzed using two (spin-degenerate) modes with different, energy-dependent transmission coefficients. Deviations from the predictions from Landauer-Buttiker formalism are assigned to electron-electron interactions.

Biodegradation of four phthalate esters in sludge

This study investigated the effects of ultrasonic pretreatment and various treatments on the aerobic degradation of four phthalic acid esters (PAEs) such as diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP) and di-(2-ethyl hexyl)phthalate (DEHP) in sludge. The effect on PAE degradation of treating sludge with a 20 min sonication period at a power level of 0.1 W ml(-1) was evaluated. The degradation rates of the four PAEs were DBP>BBP>DEP>DEHP. Degradation rate constants (k(1)) and half-lives (t(1/2)) for the four PAEs (50 mg kg(-1)) ranged from 0.182 to 0.379 day(-1) and 1.8 to 3.8 days, respectively. The optimal pH for PAE degradation in sludge was 7.0 at 30 degrees C. PAE degradation was enhanced by the addition of yeast extract, brij 30 or brij 35 and inhibited by the addition of hydrogen peroxide. Our results show that a combination of ultrasonic pretreatment and biodegradation can effectively remove PAE from sludge.

The effect of a naturalistic stressor on frontal EEG asymmetry, stress, and health

The aim of the current study was to investigate the effect of a naturalistic stressor, examination stress, on frontal EEG asymmetry, psychological stress, hormonal stress, and negative health. Forty-nine subjects were tested during periods of low and high examination stress. During the high examination stress period, subjects reported higher levels of stress on the Spielberger State Anxiety Inventory and Cohen's Perceived Stress Scale. However, no change in cortisol was detected across the two sessions. Furthermore, a shift from relatively greater left frontal activity during the low examination session to relatively greater right frontal activity during the high examination session was also found. Moreover, the increasing right frontal activity asymmetry associated with the high exam session compared to the low exam session correlated with increasing reports of negative health. No evidence was found for the prediction that cortisol mediated either the relationship between examination stressor and right frontal asymmetry or between right frontal asymmetry and negative health. In conclusion, while the findings from this study are compelling, the mechanism mediating increases in psychological stress, relatively greater right frontal activity, and increases in negative health from naturally occurring stressors is in need of further investigation.

Quantum Size Effect on Surface Photovoltage Spectra: Alpha-Fe2O3 Nanocrystals on the Surface of Monodispersed Silica Microsphere

A new method for the preparation of Fe(2)O(3) nanoparticle/SiO(2) microsphere composites is described, in which fine alpha-Fe(2)O(3) nanocrystals were prepared by forced hydrolysis of FeCl(3) aqueous solution. The structure and optical spectra of these alpha-Fe(2)O(3) nanocrystals have been studied. Their visible optical absorption can be enhanced by their adsorptions on the surface of SiO(2) microspheres and thereafter simple packing of these microspheres to the aggregated structures. The size-dependent photogenerated surface photovoltage spectra (SPS) of these composites were studied, and quantum confinement effects of the SPS properties were observed. The transport of photoinduced charges between nanocrystals with intrinsic electronic nature of confined states accounts for this phenomenon. These results are helpful in understanding the relationship among d-d transition and charge-transfer transition in transition metal oxides and find applications in photovoltaic devices.

Antisense inhibition of xylitol dehydrogenase gene, xdh1 from Trichoderma reesei

AIMS

To inhibit xylitol dehydrogenase (XDH) in Trichoderma reesei by antisense inhibition strategy and construct novel strains capable of accumulating xylitol.

METHODS AND RESULTS

The xdh1 antisense expression plasmid pGTA-xdh was constructed by inserting xdh1 DNA fragment inversely between the gpdA promoter and the trpC terminator from Aspergillus nidulans into a pUC19 plasmid backbone. Trichoderma reesei protoplasts were co-transformated with pGTA-xdh and hygromycin B resistance plasmid pAN7-1. Of 20 transformants screened from the selective medium, one transformant with the highest xylitol accumulation, designated ZY15, showed a distinct reduction (c. 52%) in XDH activity compared with the original strain Rut-C30. The results of Southern hybridization and PCR assay showed that the antisense expression cassette of xdh1 was integrated into the genome of T. reesei. The RT-PCR analysis proved that antisense RNA effectively inhibited XDH expression (c. 65%). Xylitol accumulation (2.37 mg ml(-1)) of ZY15 was five times higher than that (0.46 mg ml(-1)) of the original strain Rut-C30.

CONCLUSIONS

Strain ZY15 successfully downregulated XDH production and exhibited xylitol accumulation in xylose liquid medium.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study contributed to the budding field of fungal genetics in two points. First, it confirmed that antisense RNA strategy could be used as a means of reducing gene expression in the filamentous fungus T. reesei. Secondly, it verified that the strategy appears most promising for creating novel filamentous fungi strains capable of accumulating intermediary metabolites.

Single-crystalline Sb-doped SnO2 nanowires: synthesis and gas sensor application

The synthesis of semiconducting Sb-doped SnO2 nanowires in mass production by an in situ doping approach are reported, and the ethanol sensing results demonstrated that Sb-doped SnO2 nanowires have a promising application for the fabrication of gas sensors with low resistance, and quick response and recovery times.

Construction of a yeast one-hybrid system with the xylanase2 promoter from Trichoderma reesei to isolate transcriptional activators

AIMS

To construct a yeast one-hybrid system and isolate transcriptional activators.

METHODS AND RESULTS

A 1.1-kb promoter region of xylanase2 from Trichoderma reesei was cloned by PCR and sequenced (GenBank accession number: AY263380). Sequence analysis revealed that typical binding sites for several transcription factors in filamentous fungi, such as CREI, XLNR, ALCR, AREA and CCAAT enhancer, are located in the promoter. To isolate xyn2 transcription factors, the reporter plasmid of a yeast one-hybrid system was constructed on the backbone of the plasmid pRS415 containing the leu2 selective marker, with the xyn2 promoter region and Saccharomyces cerevisiae his4 as a reporter gene. The reporter gene contained 123-bp minimal promoter region. The S. cerevisiae H158 strain containing the reporter plasmid was transformed with a T. reesei expression cDNA library, and 34 transformants were collected from SC-Leu-His-Ura plates. The isolation of the gene ace2 from several transformants showed that the one-hybrid system approach was successful. Then, approx. 59 mg l(-1) of ace2 was overexpressed in Escherichia coli BL21.

SIGNIFICANCE AND IMPACT OF THE STUDY

The yeast one-hybrid system is suitable for isolating transcription factors of filamentous fungi. ACE II is a main and universal transcriptional activator that controls cellulase and hemicellulase transcription regulation in T. reesei.

Contribution of the gastrointestinal tract below the stomach to the 13C-urea breath test

BACKGROUND

Graham et al. [Lancet, I (1987) 1174] found a late increase of 13C enrichment in the 13C-urea breath test 120 min after administration of labeled urea to patients without Helicobacter pylori infection. This may give false positive results.

AIM

We designed this study to elucidate the contribution of the gastrointestinal tract below the stomach to the 13C-urea breath test.

PATIENTS

Twenty-eight patients with dyspeptic symptoms who gave their consent were enrolled.

METHODS

Patients underwent the 13C-urea breath tests both via the mouth (as usual) and the duodenum (labeled urea introduced to the second portion). Breath samples were collected at baseline, 5, 15, 30, 45, 60, 90, 120, 150 and 180 min for analysis. H. pylori status was defined by the CLOtest and by histological examination.

RESULTS

There was no late increase in 13C enrichment of 13C-urea breath test for eight H. pylori negative patients either via the mouth or the duodenum. For those H. pylori positive patients, seventeen had no late rise 13C enrichment of the 13C-urea breath test via the duodenum and three patients had a rise after 15 min.

CONCLUSIONS

No late rise in 13CO2 excretion to cause a positive 13C-urea breath test up to 180 min after the administration of labeled urea was found in the present study.