Genetic diversity and molecular identification of mosquito species in the Anopheles maculatus group using the ITS2 region of rDNA

The species diversity and genetic structure of mosquitoes belonging to the Anopheles maculatus group in Southeast Asia were investigated using the internal transcribed spacer 2 (ITS2) of ribosomal DNA (rDNA). A molecular phylogeny indicates the presence of at least one hitherto unrecognised species. Mosquitoes of chromosomal form K from eastern Thailand have a unique ITS2 sequence that is 3.7% divergent from the next most closely related taxon (An. sawadwongporni) in the group. In the context of negligible intraspecific variation at ITS2, this suggests that chromosomal form K is most probably a distinct species. Although An. maculatus sensu stricto from northern Thailand and southern Thailand/peninsular Malaysia differ from each other in chromosomal banding pattern and vectorial capacity, no intraspecific variation was observed in the ITS2 sequences of this species over this entire geographic area despite an extensive survey. A PCR-based identification method was developed to distinguish five species of the group (An. maculatus, An. dravidicus, An. pseudowillmori, An. sawadwongporni and chromosomal form K) to assist field-based studies in northwestern Thailand. Sequences from 187 mosquitoes (mostly An. maculatus and An. sawadwongporni) revealed no intraspecific variation in specimens from Thailand, Cambodia, mainland China, Malaysia, Taiwan and Vietnam, suggesting that this identification method will be widely applicable in Southeast Asia. The lack of detectable genetic structure also suggests that populations of these species are either connected by gene flow and/or share a recent common history.

Efficacy of antitumoral photodynamic therapy with hypericin: relationship between biodistribution and photodynamic effects in the RIF-1 mouse tumor model

We investigated the hypericin-mediated PDT effects on the tumor and normal skin and in correlation with its biodistribution. These studies were carried out on C3H mice bearing RIF-1 tumors. The hypericin distribution and PDT effects were recorded at different intervals (0.5-24 hr) after intravenous injection of a 5-mg/kg dose of hypericin. After administration, rapid biphasic exponential decay was observed in the plasma drug concentration. It was found that hypericin was preferentially bound to the plasma lipoproteins. The tumor drug levels increased rapidly over the first few hours and reached a maximum around 6 hr after injection. In contrast, PDT efficacy was maximal when irradiation was performed at 0.5 hr after hypericin administration, which led to 100% cure. The PDT efficacy decreased rapidly as the administration-irradiation interval was prolonged. No tumor cure was obtained at the 6-hr interval, even though it was at this time that the tumor drug level peaked. Fluorescence microscopic studies showed that hypericin was mainly confined within the tumor vasculature at 0.5 hr after injection, whereupon it rapidly diffused to the surrounding tumor tissue. At 6 hr, a strong hypericin fluorescence was observed in the tumor tissue with only faint fluorescence within the vasculature, whereas at 24 hr the fluorescence in the tumor also decreased and became more diffused, and no fluorescence could be seen in the tumor vasculature. Like the tumor response, skin reactions were also found to be much more dramatic at short administration-irradiation intervals. Hypericin distribution and PDT response studies revealed a close correlation between the plasma drug level and the PDT effects, which suggests that vascular damage is the primary effect of hypericin-mediated PDT in this tumor model.

Infectious cDNA clone of hypovirus CHV1-Euro7: a comparative virology approach to investigate virus-mediated hypovirulence of the chestnut blight fungus Cryphonectria parasitica

We report the construction of a full-length infectious cDNA clone for hypovirus CHV1-Euro7, which is associated with reduced virulence (hypovirulence) of the chestnut blight fungus Cryphonectria parasitica. Field strains infected with CHV1-Euro7 are more virulent and exhibit less severe phenotypic changes (hypovirulence-associated traits) than strains infected with the prototypic hypovirus CHV1-EP713, for which the first infectious cDNA clone was developed. These differences exist even though the two hypoviruses show extensive sequence identities: 87 to 93% and 90 to 98% at the nucleotide and amino acid levels, respectively. The relative contributions of viral and host genomes to phenotypic traits associated with hypovirus infection were examined by transfecting synthetic transcripts of the two hypovirus cDNAs independently into two different virus-free C. parasitica strains, EP155 and Euro7(-v). Although the contribution of the viral genome was clearly predominant, the final magnitude and constellation of phenotypic changes were a function of contributions by both genomes. The high level of sequence identity between the two hypoviruses also allowed construction of viable chimeras and mapping of the difference in symptom expression observed for the two viruses to the open reading frame B coding domain. Implications of these results for engineering enhanced biological control and elucidating the basis for hypovirus-mediated attenuation of fungal virulence are discussed.

Environmental factors in the etiology of Parkinson's disease

Parkinson's disease (PD) has been proposed to result from the interaction of aging and environment in susceptible individuals. Defective metabolism of debrisoquine, inherited as an autosomal recessive, has been associated with this susceptibility. In 35 PD patients and 19 age-matched controls, no significant differences in debrisoquine metabolism were found, although a trend to impaired metabolism was noted in patients with disease onset less than or equal to 40. Foci of PD patients were associated with rural living and well water drinking, or rural living coupled with market gardening or wood pulp mills. In a questionnaire survey, patients with PD onset less than or equal to age 47 were significantly more likely to have lived in rural areas and to have drunk well water than those with onset greater than or equal to age 54 (p less than or equal to 0.01). Because of population mobility in North America, a case-control study designed to test environmental, occupational, dietary and other proposed risk factors for PD was conducted in China, where the population is more stationary and the environment more stable. No significant differences in incidences of head trauma, smoking or childhood measles were found between patients and controls.

Decellularized kidney scaffold-mediated renal regeneration

Renal regeneration approaches offer great potential for the treatment of chronic kidney disease, but their availability remains limited by the clinical challenges they pose. In the present study, we used continuous detergent perfusion to generate decellularized (DC) rat kidney scaffolds. The scaffolds retained intact vascular trees and overall architecture, along with significant concentrations of various cytokines, but lost all cellular components. To evaluate its potential in renal function recovery, DC scaffold tissue was grafted onto partially nephrectomized rat kidneys. An increase of renal size was found, and regenerated renal parenchyma cells were observed in the repair area containing the grafted scaffold. In addition, the number of nestin-positive renal progenitor cells was markedly higher in scaffold-grafted kidneys compared to controls. Moreover, radionuclide scan analysis showed significant recovery of renal functions at 6 weeks post-implantation. Our results provide further evidence to show that DC kidney scaffolds could be used to promote renal recovery in the treatment of chronic kidney disease.

Extensive alteration of fungal gene transcript accumulation and elevation of G-protein-regulated cAMP levels by a virulence-attenuating hypovirus

Persistent infection of the chestnut blight fungus Cryphonectria parasitica with the prototypic hypovirus CHVI-713 results in attenuation of fungal virulence (hypo-virulence) and reduced accumulation of the GTP-binding (G) protein a subunit CPG-1. Transgenic cosuppression of CPG-1 accumulation in the absence of virus infection also confers hypovirulence. We now report the use of mRNA differential display to examine the extent to which virus infection alters fungal gene transcript accumulation and to assess the degree to which modification of CPG-1 signal transduction contributes to this alteration. More than 400 PCR products were identified that either increased (296 products) or decreased (127 products) in abundance as a result of virus infection. Significantly, 65% of these products exhibited similar changes as a result of CPG-1 cosuppression in the absence of virus infection. We also report that both virus infection and CPG-1 cosuppression elevate cAMP levels 3- to 5-fold. Additionally, it was possible to mimic the effect of virus infection and CPG-1 cosuppression on transcript accumulation for representative fungal genes by drug-induced elevation of cAMP levels. These results strengthen and extend previous indications that hypovirus infection causes a significant and persistent alteration of fungal gene expression/transcript accumulation. They further show that this alteration is primarily mediated through modification of the CPG-1 signaling pathway and suggest that, similar to mammalian Gi alpha subunits, CPG-1 functions as a negative modulator of adenylyl cyclase. Finally, these results suggest a role for G-protein-regulated cAMP accumulation in hypovirus-mediated alteration of fungal gene expression.

Control of spermatogenesis in mice by the cyclin D-dependent kinase inhibitors p18(Ink4c) and p19(Ink4d)

Male mice lacking both the Ink4c and Ink4d genes, which encode two inhibitors of D-type cyclin-dependent kinases (Cdks), are infertile, whereas female fecundity is unaffected. Both p18(Ink4c) and p19(Ink4d) are expressed in the seminiferous tubules of postnatal wild-type mice, being largely confined to postmitotic spermatocytes undergoing meiosis. Their combined loss is associated with the delayed exit of spermatogonia from the mitotic cell cycle, leading to the retarded appearance of meiotic cells that do not properly differentiate and instead undergo apoptosis at an increased frequency. As a result, mice lacking both Ink4c and Ink4d produce few mature sperm, and the residual spermatozoa have reduced motility and decreased viability. Whether or not Ink4d is present, animals lacking Ink4c develop hyperplasia of interstitial testicular Leydig cells, which produce reduced levels of testosterone. The anterior pituitary of fertile mice lacking Ink4c or infertile mice doubly deficient for Ink4c and Ink4d produces normal levels of luteinizing hormone (LH). Therefore, the failure of Leydig cells to produce testosterone is not secondary to defects in LH production, and reduced testosterone levels do not account for infertility in the doubly deficient strain. By contrast, Ink4d-null or double-null mice produce elevated levels of follicle-stimulating hormone (FSH). Because Ink4d-null mice are fertile, increased FSH production by the anterior pituitary is also unlikely to contribute to the sterility observed in Ink4c/Ink4d double-null males. Our data indicate that p18(Ink4c) and p19(Ink4d) are essential for male fertility. These two Cdk inhibitors collaborate in regulating spermatogenesis, helping to ensure mitotic exit and the normal meiotic maturation of spermatocytes.

Acute lung injury. Pathogenesis of intraalveolar fibrosis

In patients dying with acute lung injury, interstitial mesenchymal cells migrate into the airspace where they replicate and deposit connective tissue. We therefore hypothesized that peptides capable of promoting mesenchymal cell migration and replication would be present in the alveolar airspace. To examine this hypothesis, patients with severe acute diffuse lung injury (n = 26) underwent bronchoalveolar lavage. Acutely ill patients without lung injury served as controls (n = 12). Recovered effluent was examined for mesenchymal cell growth-promoting and migration-promoting activity. Lavage cell supernates from both patients and controls were devoid of bioactivity. However, substantial growth-promoting and migration-promoting activity was present in lavage fluid from nearly every patient, whereas little or none was present in fluid from controls. Characterization of the bioactivity indicated a significant proportion consisted of three peptides related to PDGF: (a) a 14-kD peptide that shared with PDGF several biophysical, biochemical, receptor-binding, and antigenic properties; (b) a 29-kD peptide that appeared identical to PDGF of platelet origin; and (c) a 38-kD peptide that was biophysically and antigenically similar to PDGF. These data indicate that peptide moieties are present in the airspace of patients after acute lung injury that can signal mesenchymal cell migration and replication.

Natural history of acute upper GI bleeding due to tumours: short-term success and long-term recurrence with or without endoscopic therapy

BACKGROUND

Scant information is available regarding patients with upper gastrointestinal bleeding (UGIB) from tumours.

AIM

To determine the presentation, endoscopic findings, treatment and outcomes in patients with UGIB from malignant tumours and identify risk factors associated with rebleeding.

METHODS

Consecutive patients who were hospitalised with haematemesis, melena or haematochezia and underwent upper endoscopy were identified retrospectively by reviewing an endoscopy database. Patients with UGIB due to biopsy-proven malignant tumours were studied.

RESULTS

Tumours were the source of bleeding in 106 (5%) of 2,166 patients with UGIB. Tumours were oesophageal in 17 (16%), gastric in 77 (73%) and duodenal in 12 (11%). At presentation, 84 (79%) did not have known cancer previously, and 79 (75%) had metastatic disease. Seventy-seven (73%) received transfusions at index hospitalisation. At endoscopy, 32 (30%) had active bleeding (31 oozing, 1 spurting). Among actively bleeding patients, haemostasis was achieved in 12 (86%) of 14 receiving endoscopic therapy and all 18 not receiving endoscopic treatment. Hospitalisation for rebleeding occurred in 50 (49%) of 103 at a median of 30 days (3-885). On multivariate analysis, age ≤60 years (OR = 2.49, 95% CI 1.06-5.81) and haemodynamic instability (OR = 2.42, 95% CI 1.08-5.46) were associated with rebleeding.

CONCLUSIONS

Patients presenting with tumour-associated UGIB have substantial blood loss, with three-quarters requiring transfusion at presentation. Initial haemostasis occurs in almost all patients, with or without endoscopic therapy, but rebleeding requiring repeat hospitalisation occurs in approximately half the patients and is more common in patients who are ≤60 years of age and have haemodynamic instability at presentation.

Neuroprotective effect of grafting GDNF gene-modified neural stem cells on cerebral ischemia in rats

Previous studies indicated the beneficial effects of glial cell line-derived neurotrophic factor (GDNF) and transplanted neural stem cells (NSCs) on stroke. Here, we explored whether transplantation of neural stem cells (NSCs) modified by GDNF gene provides a better therapeutic effect than native NSCs after stroke. Primary rat NSCs were transfected with GDNF plasmid (GDNF/NSCs, labeled by green fluorescent protein from AdEasy-1, GFP). Adult rats were subjected to two-hour middle cerebral artery occlusion and reperfusion, followed by infusion of NSCs (labeled with5-bromo-2'-deoxyuridine before infusion, BrdU), GDNF/NSCs and saline at 3 days after reperfusion (NSCs group, GDNF/NSCs group, control group), respectively. All rats were sacrificed at 1, 2, 3, 5, and 7 weeks after reperfusion. Modified Neurological Severity Scores (mNSS) test and H and E staining were respectively performed to evaluate neurological function and lesion volume. Immunohistochemistry was used to identify implanted cells and observe the expressions of Synaptophysin (Syp) and postsynaptic density-95 (PSD-95) and caspase-3. TdT-mediated dUTP-biotin nick-end labeling (TUNEL) was employed to observe apoptotic cells. Western blotting was used to detect brain-derived neurotrophic factor (BDNF) and NT-3 protein expression. Significant recovery of mNSS was found in GDNF/NSCs rats at 2 and 3 weeks after reperfusion compared with NSCs rats. Lesion volume in the NSCs and GDNF/NSCs groups was reduced significantly compared with control group. The number of NSCs in the GDNF/NSCs group was significantly increased in comparison with NSCs group. Moreover, Syp-immunoreactive product at 2 and 3 weeks after reperfusion and PSD-95 immunoreactive product in the GDNF/NSCs group were significantly increased compared with NSCs group. In contrast, caspase-3 positive cells and TUNEL-positive cells in the GDNF/NSCs group were significantly decreased compared with NSCs group. Significant increase of BDNF protein in the GDNF/NSCs and NSCs groups was observed compared to the control group at different time points of reperfusion, and GDNF/NSCs grafting significantly increased BDNF protein expression compared to NSCs grafting. In addition, significant increase of NT-3 protein in GDNF/NSCs and NSCs groups was detected only at 1 week of reperfusion compared to control group. The results demonstrate that grafting NSCs modified by GDNF gene provides better neuroprotection for stroke than NSCs grafting alone.

Circadian rhythms in light-evoked responses of the fly's compound eye, and the effects of neuromodulators 5-HT and the peptide PDF

Two sets of wide-field neurons extend neurites into the fly's optic lamina, where monopolar cells receive photoreceptor input. They exhibit immunoreactivity to antibodies raised against either 5-hydroxytryptamine or the crustacean peptide PDH, respectively. Both are proposed whole-field neuromodulators of vision, apparently regulating a circadian rhythm of monopolar cell size. Seeking functional correlates, we have re-examined the electroretinogram for circadian rhythmicity, and for responses to locally injected 5-hydroxytryptamine and peptide. Long-term electroretinogram recordings from Calliphora entrained to a light/dark cycle and then transferred to constant darkness, uncovered a gradual, modest increase during the subjective night in the electroretinogram's ON- and OFF-transients, from the lamina's monopolar cells. Five to twenty nl of 5-hydroxytryptamine (10(-3) mol.1(-1)) injected into the head haemolymph strongly enhanced the electroretinogram transients, an action reversed by 5-hydroxytryptamine antagonists. Injected into the eye, 5-hydroxytryptamine (10(-4) mol.1(-1)) had the opposite effect; the rapid onset there suggests direct action, whilst the opposing effect from haemolymph injection suggests a different receptor site. Pigment-dispersing hormone (2.2 x 10(-5) mol.1(-1)) injected into the haemolymph increased the electroretinogram transients along a biphasic course, with a slow partial recovery; injected into the eye, it lacked effect.

Differential responses of migratory locusts to systemic RNA interference via double-stranded RNA injection and feeding

The migratory locust, Locusta migratoria, is one of the most destructive agricultural pests and has been widely used as a model system for insect physiology, neurobiology and behavioural research. In the present study, we investigated the effects of RNA interference (RNAi) using two delivery methods for double-stranded RNA (dsRNA) molecules, namely, injection and feeding, to develop a potential new pest control strategy. Our results showed that locusts have a sensitive and systemic response to the injection of dsRNAs in a dose-dependent manner, but do not respond to the feeding of dsRNAs. Further experiments suggested that the ineffectiveness of dsRNA feeding was attributable to the rapid degradation of dsRNA, which was probably induced by nuclease enzymes in the locust midgut. Moreover, we identified almost all the homologous genes involved in the endocytosis-mediated dsRNA uptake from the locust genome, which provided possible clues regarding the dsRNA uptake mechanisms from the intestine to the midgut epithelium. These findings reveal the differential response models of fourth instar locust nymphs to dsRNA delivery methods, contribute to the current understanding of insect RNAi mechanisms and provide important information for the further application of RNAi as a genetic tool and pest control strategy.

Hierarchical modelling of attachment and detachment mechanisms of gecko toe adhesion

The mechanics of reversible adhesion of the gecko is investigated in terms of the attachment and detachment mechanisms of the hierarchical microstructures on its toe. At the bottom of the hierarchy, we show that a spatula pad of tiny thickness can be well absorbed onto a substrate with a large surface area and a highly constrained decohesion process zone, both of which are beneficial for robust attachment. With different peeling angles, the peeling strength of a spatula pad for attachment can be 10 times larger than that for detachment. At the intermediate level of hierarchy, we show that a seta can achieve a stress level similar to that in the spatula pad by uniformly distributing adhesion forces; as a consequence, the 10 times difference in the peel-off force of a single spatula pad for attachment and detachment is magnified up to a 100 times difference in adhesion energy at the level of seta. At the top of the hierarchy, the attachment process of a gecko toe is modelled as a pad under displacement-controlled pulling, leading to an adhesive force much larger than the gecko's body weight, while the associated detachment process is modelled as a pad under peeling, resulting in a negligible peel-off force. The present work reveals, in a more systematic way than previous studies in the literature, that the hierarchical microstructures on the gecko's toe can indeed provide the gecko with robust adhesion for attachment and reversible adhesion for easy detachment at the same time.

Photodynamic therapy efficacy and tissue distribution of hypericin in a mouse P388 lymphoma tumor model

The phototherapeutic properties and tissue distribution of hypericin were investigated in DBA/2 mice bearing subcutaneously transplanted P388 lymphoma cells. The efficacy of the photodynamic therapy (PDT) 2 h after administration of hypericin (2, 5, or 20 mg/kg, i.p., 120 J/cm2, 595 nm) was substantially greater than the efficacy after a 24 h interval. PDT with Photofrin (5 mg/kg, i.p., 24-h interval, 120 J/cm2, 630 nm) showed no significant antitumoral effect. The hypericin uptake in some tissues was measured after administration of hypericin (5 or 20 mg/kg, i.p.) up to 168 h. A comparison of the distribution data and the PDT efficacy at various intervals suggests that the plasma concentration of hypericin, and to a lesser extent the tumor uptake, determines the tumor response to PDT with hypericin.

Flat panel detector-based cone-beam volume CT angiography imaging: system evaluation

Preliminary evaluation of recently developed large-area flat panel detectors (FPDs) indicates that FPDs have some potential advantages: compactness, absence of geometric distortion and veiling glare with the benefits of high resolution, high detective quantum efficiency (DQE), high frame rate and high dynamic range, small image lag (< 1%), and excellent linearity (approximately 1%). The advantages of the new FPD make it a promising candidate for cone-beam volume computed tomography (CT) angiography (CBVCTA) imaging. The purpose of this study is to characterize a prototype FPD-based imaging system for CBVCTA applications. A prototype FPD-based CBVCTA imaging system has been designed and constructed around a modified GE 8800 CT scanner. This system is evaluated for a CBVCTA imaging task in the head and neck using four phantoms and a frozen rat. The system is first characterized in terms of linearity and dynamic range of the detector. Then, the optimal selection of kVps for CBVCTA is determined and the effect of image lag and scatter on the image quality of the CBVCTA system is evaluated. Next, low-contrast resolution and high-contrast spatial resolution are measured. Finally, the example reconstruction images of a frozen rat are presented. The results indicate that the FPD-based CBVCT can achieve 2.75-lp/mm spatial resolution at 0% modulation transfer function (MTF) and provide more than enough low-contrast resolution for intravenous CBVCTA imaging in the head and neck with clinically acceptable entrance exposure level. The results also suggest that to use an FPD for large cone-angle applications, such as body angiography, further investigations are required.

Dose-dependent ras mutation spectra in N-nitrosodiethylamine induced mouse liver tumors and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induced mouse lung tumors

In a previous study, the spectrum of H-ras mutations detected in B6C3F1 mouse liver tumors induced by 5, 50 or 150 mumol/kg body wt of N-nitrosodiethylamine (NDEA) was similar to that in spontaneous B6C3F1 mouse liver tumors, suggesting that activation of the H-ras gene in NDEA-induced mouse liver tumors may not be the direct result of the chemical interaction with the H-ras gene. In the present study, mutations in the H-ras oncogene from B6C3F1 mouse liver tumors induced by 5 or 50 mumol/kg body wt of NDEA were characterized by DNA amplification with polymerase chain reaction (PCR), single-strand conformation of polymorphism (SSCP) and direct sequence analysis. Twenty-one of 66 NDEA-induced B6C3F1 mouse liver tumors contained activated H-ras gene with 2 of 21 having a CG to AT transversion at the first base of codon 61, 17 of 21 having AT to GC transition and 2 of 21 having an AT to TA transversion at the second base of codon 61 in the H-ras gene. The predominant mutation, AT to GC transition (17/21, 81%) is consistent with the formation of O4-ethylthymine adduct, and is distinct from the predominant CG to AT transversion (50%) at the first base of codon 61 detected in H-ras gene from NDEA-induced B6C3F1 mouse liver tumors in a previous study by Stowers et al. Mutations in the K-ras oncogene from 59 A/J mouse lung tumors induced by 0.53 mmol/kg body wt of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were also characterized by using the above mentioned methods. Forty-six of 59 NNK-induced A/J mouse lung tumors contained activated K-ras genes. All 46 (100%) of the activated K-ras gene had GC to AT transitions at the second base of codon 12. The same mutation was observed in 70% (7/10) of the K-ras oncogene from A/J lung tumors induced by 4.8 mmol/kg body wt (given in 21 doses) of NNK. These data suggest that other factors in addition to genotoxic effect might be involved in the induction of rodent tumors by some carcinogens when given at higher doses. Therefore, further studies to compare the dose-dependent differences in the profile of ras mutations induced by chemical carcinogens may help to assess human cancer risk. Mutation(s) in exons 5-8 of the p53 gene was not found in these NDEA-induced mouse liver tumors and NNK-induced mouse lung tumors.

Association study of dopamine D2, D3 receptor gene polymorphisms with motor fluctuations in PD

The authors investigated the association between dopamine receptor D2, D3 gene polymorphisms, and the risk of developing motor fluctuations in PD. DRD3 BalI and MspI polymorphisms were not associated with risk of developing motor fluctuations. However, the genotypic distribution of DRD2 TaqIA polymorphism was significantly different in motor fluctuators and nonmotor fluctuators. These findings suggest that DRD2 TaqIA polymorphism may be associated with an increased risk for developing motor fluctuations in PD.

Regulation of autophagy by miR-30d impacts sensitivity of anaplastic thyroid carcinoma to cisplatin

miR-30d has been observed to be significantly down-regulated in human anaplastic thyroid carcinoma (ATC), and is believed to be an important event in thyroid cell transformation. In this study, we found that miR-30d has a critical role in modulating sensitivity of ATC cells to cisplatin, a commonly used chemotherapeutic drug for treatment of this neoplasm. Using a mimic of miR-30d, we demonstrated that miR-30d could negatively regulate the expression of beclin 1, a key autophagy gene, leading to suppression of the cisplatin-activated autophagic response that protects ATC cells from apoptosis. A reporter gene assay demonstrated that the binding sequences of miR-30d in the beclin 1-3' UTR was the region required for the inhibition of beclin 1 expression by this miRNA. We further showed that inhibition of the beclin 1-mediated autophagy by the miR-30d mimic sensitized ATC cells to cisplatin both in vitro (cell culture) and in vivo (animal xenograft model). These results suggest that dysregulation of miR-30d in ATC cells is responsible for the insensitivity to cisplatin by promoting autophagic survival. Thus, miR-30d may be exploited as a potential target for therapeutic intervention in the treatment of ATC.

The feedback circuit connecting the superior colliculus and central mesencephalic reticular formation: a direct morphological demonstration

The central mesencephalic reticular formation (cMRF) has been distinguished from the surrounding reticular formation due to its involvement in the control of saccades. A role in saccade function has been proposed for this region based on electrical-stimulation experiments, its neuronal activity, and its pattern of connections. The present study was undertaken in an attempt to further characterize the location of the central mesencephalic reticular formation by anatomical methods and to examine its connections with the superior colliculus at the neuronal level. Biotinylated dextran amine (BDA) was injected into the superior colliculus of two cynomolgus monkeys (Macaca fascicularis). This resulted in the retrograde labeling of a large number of neurons in a restricted area of the mesencephalic reticular formation. They were distributed bilaterally, with an ipsilateral predominance, forming a cellular band in the ventral half of the midbrain reticular formation that was 2.7 mm in its rostrocaudal extent. Its rostral pole lay dorsolateral to the red nucleus and ventrolateral to, but not immediately adjacent to, the interstitial nucleus of Cajal. The cell band was widest caudally, where it occupied an area of approximately 2.7 mm wide and 2 mm in depth. Labeled neurons displayed a wide variety of multipolar somatic shapes and sizes, with long, slightly tapering, sparsely branched dendrites. Tectal terminal arbors were also labeled within the mesencephalic reticular formation. They were concentrated bilaterally, with an ipsilateral predominance, in the same areas that contained retrogradely labeled neurons. Numerous, primarily en passant labeled boutons of various sizes and shapes were seen in close association with both labeled and unlabeled neurons. They formed axosomatic and, more commonly, axodendritic relationships with labeled neurons. The extensive relationship of labeled terminals and labeled cells suggests the existence of a strong interconnection between the deeper layers of the colliculus and the central mesencephalic reticular formation neurons projecting back to the tectum. The bidirectional neural circuit directly demonstrated in this study presumably provides an anatomical substrate for feedback modification of gaze signals generated in the colliculus. However, the presence of tectal terminals around unlabeled reticular neurons suggests that the collicular signal may also be fed forward to the downstream targets of the central mesencephalic reticular formation.

Mapping of Drosophila mutations using site-specific male recombination

Although recombination does not usually occur in the male Drosophila germline, site-specific recombination can be induced at the ends of P elements. This finding suggested that male recombination could be used to map Drosophila mutations. In this article, we describe the general method and its application to the mapping of two EMS-induced female-sterile mutations, grauzone and cortex. Within two months, the grauzone gene was mapped relative to seven different P-element insertion sites, and cortex was mapped relative to 23 different P-elements. The results allowed us to map grauzone to a region of about 50 kb, and cortex distal to the chromosomal region 33E. These experiments demonstrate that P-element-induced site-specific male recombination is an efficient and general method to map Drosophila autosomal mutations.

Associations of miRNA polymorphisms and female physiological characteristics with breast cancer risk in Chinese population

mircoRNAs (miRNAs) play important roles on regulation of gene expressions. Aberrant expression of miRNAs was involved in various biological and pathological processes, including tumorigenesis of breast cancer. Single-nucleotide polymorphisms (SNPs) were implicated in altered expression or biological functions of mature miRNAs. To explore the relevance of miRNA polymorphisms and female physiological characteristics to breast cancer risk, SNPs located within hsa-miR-605 (rs2043556), hsa-miR-149 (rs2292832), hsa-miR-27a (rs895819), hsa-miR-196a-2 (rs11614913) and hsa-miR-618 (rs2682818) were selected, and their associations with breast cancer risk were analysed. In addition, associations between physiological characteristics-related factors and breast cancer risk were estimated too. We found that the ones with menarche age less than 16 years had increased breast cancer risk (OR = 2.10, 95% CI: 1.23-3.60). Marginally significant association between rs11614913 CT/CC genotypes and reduced breast cancer risk was observed (OR = 0.65, 95% CI: 0.40-1.06), while no significance was detected about the other miRNA polymorphisms. We concluded that menarche at less than 16 years old increased breast cancer risk, while the genetic variants in miR-196-a-2 might decrease the risk.

Flk-1+ mesenchymal stem cells aggravate collagen-induced arthritis by up-regulating interleukin-6

The immunomodulatory ability of mesenchymal stem cells (MSCs) may be used to develop therapies for autoimmune diseases. Flk-1(+) MSCs are a population of MSCs with defined phenotype and their safety has been evaluated in Phase 1 clinical trials. We designed this study to evaluate whether Flk-1(+) MSCs conferred a therapeutic effect on collagen-induced arthritis (CIA), an animal model of rheumatic arthritis, and to explore the underlying mechanisms. Flk-1(+) MSCs, 1-2 x 10(6), were injected into CIA mice on either day 0 or day 21. The clinical course of arthritis was monitored. Serum cytokine profile was determined by cytometric bead array kit or enzyme-linked immunosorbent assay. Flk-1(+) MSCs and splenocytes co-culture was conducted to explore the underlying mechanisms. Flk-1(+) MSCs did not confer therapeutic benefits. Clinical symptom scores and histological evaluation suggested aggravation of arthritis in mice treated with MSCs at day 21. Serum cytokine profile analysis showed marked interleukin (IL)-6 secretion immediately after MSC administration. Results of in vitro culture of splenocytes confirmed that the addition of Flk-1(+) MSCs promoted splenocyte proliferation and increased IL-6 and IL-17 secretion. Moreover, splenocyte proliferation was also enhanced in mice treated with MSCs at day 21. Accordingly, MSCs at low concentrations were found to promote lipopolysaccharide-primed splenocytes proliferation in an in vitro co-culture system. We propose that Flk-1(+) MSCs aggravate arthritis in CIA model by at least up-regulating secretion of IL-6, which favours Th17 differentiation. When Flk-1(+) MSCs are used for patients, we should be cautious about subjects with rheumatoid arthritis.

Divergent effects of AKI to CKD models on inflammation and fibrosis

Chronic kidney disease (CKD) is a condition with significant morbidity and mortality that affects 15% of adults in the United States. One cause of CKD is acute kidney injury (AKI), which commonly occurs secondary to sepsis, ischemic events, and drug-induced nephrotoxicity. Unilateral ischemia-reperfusion injury (UIRI) without contralateral nephrectomy (CLN) and repeated low-dose cisplatin (RLDC) models of AKI to CKD demonstrate responses characteristic of the transition; however, previous studies have not effectively compared the pathogenesis. We demonstrate both models instigate renal dysfunction, inflammatory cytokine responses, and fibrosis. However, the models exhibit differences in urinary excretory function, inflammatory cell infiltration, and degree of fibrotic response. UIRI without CLN demonstrated worsening perfusion and function, measured with ^99mTc-mercaptoacetyltriglycine-3 imaging, and physiologic compensation in the contralateral kidney. Furthermore, UIRI without CLN elicited a robust inflammatory response that was characterized by a prolonged polymorphonuclear cell and natural killer cell infiltrate and an early expansion of kidney resident macrophages, followed by T-cell infiltration. Symmetrical diminished function occurred in RLDC kidneys and progressively worsened until day 17 of the study. Surprisingly, RLDC mice demonstrated a decrease in inflammatory cell numbers relative to controls. However, RLDC kidneys expressed increased levels of kidney injury molecule-1 (KIM-1), high mobility group box-1 ( HMGB1), and colony stimulating factor-1 ( CSF-1), which likely recruits inflammatory cells in response to injury. These data emphasize how the divergent etiologies of AKI to CKD models affect the kidney microenvironment and outcomes. This study provides support for subtyping AKI by etiology in human studies, aiding in the elucidation of injury-specific pathophysiologic mechanisms of the AKI to CKD transition.