Acto3D: an open-source user-friendly volume rendering software for high-resolution 3D fluorescence imaging in biology

Advances in fluorescence microscopy and tissue-clearing have revolutionised 3D imaging of fluorescently labelled tissues, organs and embryos. However, the complexity and high cost of existing software and computing solutions limit their widespread adoption, especially by researchers with limited resources. Here, we present Acto3D, an open-source software, designed to streamline the generation and analysis of high-resolution 3D images of targets labelled with multiple fluorescent probes. Acto3D provides an intuitive interface for easy 3D data import and visualisation. Although Acto3D offers straightforward 3D viewing, it performs all computations explicitly, giving users detailed control over the displayed images. Leveraging an integrated graphics processing unit, Acto3D deploys all pixel data to system memory, reducing visualisation latency. This approach facilitates accurate image reconstruction and efficient data processing in 3D, eliminating the need for expensive high-performance computers and dedicated graphics processing units. We have also introduced a method for efficiently extracting lumen structures in 3D. We have validated Acto3D by imaging mouse embryonic structures and by performing 3D reconstruction of pharyngeal arch arteries while preserving fluorescence information. Acto3D is a cost-effective and efficient platform for biological research.

Interpersonal sensitivity and persistent attenuated psychotic symptoms in adolescence

Interpersonal sensitivity defines feelings of inner-fragility in the presence of others due to the expectation of criticism or rejection. Interpersonal sensitivity was found to be related to attenuated positive psychotic symptom during the prodromal phase of psychosis. The aims of this study were to examine if high level of interpersonal sensitivity at baseline are associated with the persistence of attenuated positive psychotic symptoms and general psychopathology at 18-month follow-up. A sample of 85 help-seeking individuals (mean age = 16.6, SD = 5.05) referred an Italian early detection project, completed the interpersonal sensitivity measure and the structured interview for prodromal symptoms (SIPS) at baseline and were assessed at 18-month follow-up using the SIPS. Results showed that individuals with high level of interpersonal sensitivity at baseline reported high level of attenuated positive psychotic symptoms (i.e., unusual thought content) and general symptoms (i.e., depression, irritability and low tolerance to daily stress) at follow-up. This study suggests that being "hypersensitive" to interpersonal interactions is a psychological feature associated with attenuated positive psychotic symptoms and general symptoms, such as depression and irritability, at 18-month follow-up. Assessing and treating inner-self fragilities may be an important step of early detection program to avoid the persistence of subtle but very distressing long-terms symptoms.

GFRA2 Identifies Cardiac Progenitors and Mediates Cardiomyocyte Differentiation in a RET-Independent Signaling Pathway

A surface marker that distinctly identifies cardiac progenitors (CPs) is essential for the robust isolation of these cells, circumventing the necessity of genetic modification. Here, we demonstrate that a Glycosylphosphatidylinositol-anchor containing neurotrophic factor receptor, Glial cell line-derived neurotrophic factor receptor alpha 2 (Gfra2), specifically marks CPs. GFRA2 expression facilitates the isolation of CPs by fluorescence activated cell sorting from differentiating mouse and human pluripotent stem cells. Gfra2 mutants reveal an important role for GFRA2 in cardiomyocyte differentiation and development both in vitro and in vivo. Mechanistically, the cardiac GFRA2 signaling pathway is distinct from the canonical pathway dependent on the RET tyrosine kinase and its established ligands. Collectively, our findings establish a platform for investigating the biology of CPs as a foundation for future development of CP transplantation for treating heart failure.

Alternatively activated macrophages determine repair of the infarcted adult murine heart

Alternatively activated (also known as M2) macrophages are involved in the repair of various types of organs. However, the contribution of M2 macrophages to cardiac repair after myocardial infarction (MI) remains to be fully characterized. Here, we identified CD206+F4/80+CD11b+ M2-like macrophages in the murine heart and demonstrated that this cell population predominantly increases in the infarct area and exhibits strengthened reparative abilities after MI. We evaluated mice lacking the kinase TRIB1 (Trib1-/-), which exhibit a selective depletion of M2 macrophages after MI. Compared with control animals, Trib1-/- mice had a catastrophic prognosis, with frequent cardiac rupture, as the result of markedly reduced collagen fibril formation in the infarct area due to impaired fibroblast activation. The decreased tissue repair observed in Trib1-/- mice was entirely rescued by an external supply of M2-like macrophages. Furthermore, IL-1α and osteopontin were suggested to be mediators of M2-like macrophage-induced fibroblast activation. In addition, IL-4 administration achieved a targeted increase in the number of M2-like macrophages and enhanced the post-MI prognosis of WT mice, corresponding with amplified fibroblast activation and formation of more supportive fibrous tissues in the infarcts. Together, these data demonstrate that M2-like macrophages critically determine the repair of infarcted adult murine heart by regulating fibroblast activation and suggest that IL-4 is a potential biological drug for treating MI.

Single-Cell Expression Profiling Reveals a Dynamic State of Cardiac Precursor Cells in the Early Mouse Embryo

In the early vertebrate embryo, cardiac progenitor/precursor cells (CPs) give rise to cardiac structures. Better understanding their biological character is critical to understand the heart development and to apply CPs for the clinical arena. However, our knowledge remains incomplete. With the use of single-cell expression profiling, we have now revealed rapid and dynamic changes in gene expression profiles of the embryonic CPs during the early phase after their segregation from the cardiac mesoderm. Progressively, the nascent mesodermal gene Mesp1 terminated, and Nkx2-5+/Tbx5+ population rapidly replaced the Tbx5low+ population as the expression of the cardiac genes Tbx5 and Nkx2-5 increased. At the Early Headfold stage, Tbx5-expressing CPs gradually showed a unique molecular signature with signs of cardiomyocyte differentiation. Lineage-tracing revealed a developmentally distinct characteristic of this population. They underwent progressive differentiation only towards the cardiomyocyte lineage corresponding to the first heart field rather than being maintained as a progenitor pool. More importantly, Tbx5 likely plays an important role in a transcriptional network to regulate the distinct character of the FHF via a positive feedback loop to activate the robust expression of Tbx5 in CPs. These data expands our knowledge on the behavior of CPs during the early phase of cardiac development, subsequently providing a platform for further study.

CYP26B1 promotes male germ cell differentiation by suppressing STRA8-dependent meiotic and STRA8-independent mitotic pathways

Germ cell sex is defined by factors derived from somatic cells. CYP26B1 is known to be a male sex-promoting factor that inactivates retinoic acid (RA) in somatic cells. In CYP26B1-null XY gonads, germ cells are exposed to a higher level of RA than in normal XY gonads and this activates Stra8 to induce meiosis while male-specific gene expression is suppressed. However, it is unknown whether meiotic entry by an elevated level of RA is responsible for the suppression of male-type gene expression. To address this question, we have generated Cyp26b1/Stra8 double knockout (dKO) embryos. We successfully suppressed the induction of meiosis in CYP26B1-null XY germ cells by removing the Stra8 gene. Concomitantly, we found that the male genetic program represented by the expression of NANOS2 and DNMT3L was totally rescued in about half of dKO germ cells, indicating that meiotic entry causes the suppression of male differentiation. However, half of the germ cells still failed to enter the appropriate male pathway in the dKO condition. Using microarray analyses together with immunohistochemistry, we found that KIT expression was accompanied by mitotic activation, but was canceled by inhibition of the RA signaling pathway. Taken together, we conclude that inhibition of RA is one of the essential factors to promote male germ cell differentiation, and that CYP26B1 suppresses two distinct genetic programs induced by RA: a Stra8-dependent meiotic pathway, and a Stra8-independent mitotic pathway.

First Confirmed Case of Vancomycin-ResistantEnterococcus faeciumMeningitis in Turkey:

Vancomycin-resistant enterococci are unusual etiologic agents of bacterial meningitis and pose significant therapeutic difficulties. We report the first confirmed case of nosocomial vancomycin-resistant Enterococcus faecium meningitis in Turkey. The patient was treated with chloramphenicol and cerebrospinal fluid cultures became negative, but clinical success was not achieved. We also review the previously reported cases of vancomycin-resistant Enterococcus faecium meningitis.

Nodal/activin signaling promotes male germ cell fate and suppresses female programming in somatic cells

Testicular development in the mouse is triggered in somatic cells by the function of Sry followed by the activation of fibroblast growth factor 9 (FGF9), which regulates testicular differentiation in both somatic and germ cells. However, the mechanism is unknown. We show here that the nodal/activin signaling pathway is activated in both male germ cells and somatic cells. Disruption of nodal/activin signaling drives male germ cells into meiosis and causes ectopic initiation of female-specific genes in somatic cells. Furthermore, we prove that nodal/activin-A works directly on male germ cells to induce the male-specific gene Nanos2 independently of FGF9. We conclude that nodal/activin signaling is required for testicular development and propose a model in which nodal/activin-A acts downstream of fibroblast growth factor signaling to promote male germ cell fate and protect somatic cells from initiating female differentiation.

Rhox13 is translated in premeiotic germ cells in male and female mice and is regulated by NANOS2 in the male

Male and female germ cells enter meiosis in response to an extrinsic cue by retinoic acid (RA), but the pathways downstream of RA signaling that regulate early gametogenesis remain uncertain. We identified a novel reproductive homeobox gene, Rhox13, transcribed in the prenatal ovary and testis beginning on Embryonic Day (E) 13.5. Translation of RHOX13 also begins in female germ cells on E13.5 but is suppressed in male germ cells until Postnatal Day 3. Translation of RHOX13 coincides with initiation of RA signaling in both male and female gonads in vivo but occurs precociously in neonatal testes exposed to RA in vitro or in fetal male germ cells when NANOS2 is absent in vivo. Conversely, RHOX13 translation in female germ cells is suppressed in the presence of ectopically induced NANOS2. These results strongly suggest that RHOX13 expression is regulated at a posttranscriptional step by direct interaction of NANOS2 with Rhox13 mRNA to suppress translation.

Interaction between NANOS2 and the CCR4-NOT deadenylation complex is essential for male germ cell development in mouse

Nanos is one of the evolutionarily conserved proteins implicated in germ cell development and we have previously shown that it interacts with the CCR4-NOT deadenylation complex leading to the suppression of specific RNAs. However, the molecular mechanism and physiological significance of this interaction have remained elusive. In our present study, we identify CNOT1, a component of the CCR4-NOT deadenylation complex, as a direct factor mediating the interaction with NANOS2. We find that the first 10 amino acids (AAs) of NANOS2 are required for this binding. We further observe that a NANOS2 mutant lacking these first 10 AAs (NANOS2-ΔN10) fails to rescue defects in the Nanos2-null mouse. Our current data thus indicate that the interaction with the CCR4-NOT deadenylation complex is essential for NANOS2 function. In addition, we further demonstrate that NANOS2-ΔN10 can associate with specific mRNAs as well as wild-type NANOS2, suggesting the existence of other NANOS2-associated factor(s) that determine the specificity of RNA-binding independently of the CCR4-NOT deadenylation complex.

The Nanos3-3'UTR is required for germ cell specific NANOS3 expression in mouse embryos

BACKGROUND

The regulation of gene expression via a 3' untranslated region (UTR) plays essential roles in the discrimination of the germ cell lineage from somatic cells during embryogenesis. This is fundamental to the continuation of a species. Mouse NANOS3 is an essential protein required for the germ cell maintenance and is specifically expressed in these cells. However, the regulatory mechanisms that restrict the expression of this gene in the germ cells is largely unknown at present.

METHODOLOGY/PRINCIPAL FINDINGS

In our current study, we show that differences in the stability of Nanos3 mRNA between germ cells and somatic cells is brought about in a 3'UTR-dependent manner in mouse embryos. Although Nanos3 is transcribed in both cell lineages, it is efficiently translated only in the germ lineage. We also find that the translational suppression of NANOS3 in somatic cells is caused by a 3'UTR-mediated mRNA destabilizing mechanism. Surprisingly, even when under the control of the CAG promoter which induces strong ubiquitous transcription in both germ cells and somatic cells, the addition of the Nanos3-3'UTR sequence to the coding region of exogenous gene was effective in restricting protein expression in germ cells.

CONCLUSIONS/SIGNIFICANCE

Our current study thus suggests that Nanos3-3'UTR has an essential role in translational control in the mouse embryo.

[Depressive and anxiety symptoms in a community sample of young adults and correlation with help-seeking behavior]

AIMS

To evaluate: (i) self-perceived stress, depressive and anxiety symptoms in a community sample of young adults; (ii) which elements have most impact on the development of mental disease; (iii) if high levels of mental disease are related to help-seeking behavior.

MATERIALS AND METHODS

The study was carried out on a sample of 1660 university students. The evaluation of the perceived stress was conducted using the Stress-Related Vulnerability Scale (SVS), the evaluation of depressive and anxiety symptoms with Beck Depression Inventory-II (BDI-II) and Beck Anxiety Inventory (BAI). A descriptive analysis of all the data collected was carried out and the principal links between variables and level of mental disease were detected. Finally the reasons for the failure to seek help were investigated.

RESULTS

Mean scores of BDI-II and BAI were respectively 10.9 (sigma = 8.3) and 11.4 (sigma = 9.4) and about 4% of the sample showed a pathological level of stress with the SVS. Female sex, non resident status and conflictual family climate were found to be more related with more severe anxious and depressive symptoms. Moreover, the latter ones were found to be strongly related with help-seeking behavior.

CONCLUSION

In this sample mental disease associated with distress show a significant percentage. Higher level of anxiety and depressive symptoms are more related to perceived need for help and help-seeking behavior. Nevertheless the level of unexpressed help-seeking turn out to be high for multiple reason.

Hepatic toxocariasis: US, CT and MRI findings

Visceral larva migrans (VLM) most commonly occurs as a febrile disease of childhood particularly affecting children between 1 and 7 years of age. Pulmonary, dermatological, hepatic, lymphatic, cardiac, rheumatological and neurological manifestations may occur. VLM seems to be a rare disease in adults. We report the imaging findings of a woman with hepatic toxocariasis. Ultrasonography showed a solitary hepatic lesion measuring 4 x 3 cm, displaying a hypoechoic-heterogeneous pattern with ill-defined borders and distal acoustic enhancement, located in the right sub-diaphragmatic area. Two enlarged periportal lymph nodes and moderately dilated intrahepatic biliary ducts were also noted. The probability of toxocariasis was discussed, based on sonographic and biopsy findings, and the final diagnosis was confirmed by a specific ELISA test. In summary, a clinical picture of cholestasis initially resembling hepatitis or malignancy should be further evaluated by imaging techniques, and the ultrasound examiner should be familiar with the possible findings of hepatic toxocariasis, which consist of focal ill-defined hepatic lesions, hepato-splenomegaly, biliary dilatation, sludge and periportal lymph node enlargement.

Commissural neuron identity is specified by a homeodomain protein, Mbh1,that is directly downstream of Math1

Proneural basic helix-loop-helix (bHLH) proteins are key regulators of neurogenesis. However, downstream target genes of the bHLH proteins remain poorly defined. Mbh1 confers commissural neuron identity in the spinal cord. Enhancer analysis using transgenic mice revealed that Mbh1 expression required an E-box 3′ of the Mbh1 gene. Mbh1 expression was lost in Math1 knockout mice, whereas misexpression of Math1 induced ectopic expression of Mbh1. Moreover, Math1 bound the Mbh1 enhancer containing the E-box in vivo and activated gene expression. Generation of commissural neurons by Math1 was inhibited by a dominant negative form of Mbh1. These findings indicate that Mbh1 is necessary and sufficient for the specification of commissural neurons,as a direct downstream target of Math1.

Effect of chronic Pseudomonas aeruginosa infection on the development of atherosclerosis in a rat model

In order to investigate the possible relationship between atherosclerosis and chronic Pseudomonas aeruginosa infection, 66 Wistar rats were given five separate intratracheal inoculations of either P. aeruginosa or sterile saline at 4-week intervals. The rats were divided into four groups: group 1 was infected with P. aeruginosa and fed a diet containing cholesterol 1% w/v; group 2 was infected with P. aeruginosa and fed a normal diet; group 3 was not infected and was fed a diet containing cholesterol 1% w/v; and group 4 (the control group) was not infected and was fed a normal diet. One month after the final inoculation, the rats were killed humanely; computerised image analysis was used to evaluate sections of the aorta and heart, and the maximal wall thickness of the aorta and coronary artery. The aortic wall thickness was significantly greater for group 1 (329.53 +/- 58.06 microm) compared to groups 2 (190.59 +/- 27.81 microm; p < 0.0001), 3 (262.90 +/- 61.12 microm; p < 0.0004) and 4 (158.00 +/- 30.30 microm; p < 0.0001). Similarly, the coronary artery wall thickness was significantly greater for group 1 (72.96 +/- 10.67 microm) compared to groups 2 (35.07 +/- 8.53 microm; p < 0.0001), 3 (41.45 +/- 10.22 microm; p < 0.0001) and 4 (32.30 +/- 5.27 microm; p < 0.0001). These findings strengthen the hypothesis that chronic infection plays a role in the pathogenesis of atherosclerosis.

Human fascioliasis

Fasciola hepatica, a zoonotic liver fluke, can also cause disease in humans. Common symptoms are epigastric pain, upper abdominal pain and malaise. Fever and arthralgia are common in acute fascioliasis. Eosinophilia is the predominant laboratory finding, especially in patients with the acute form of the disease. Diagnosis and treatment is not easy, as physicians rarely encounter this disease, and effective drugs are not available in many countries. Human fascioliasis may be underestimated. Patients with eosinophilia and abdominal pain should be evaluated for F. hepatica infestation by parasitological, radiological and serological tests.

Mammalian BarH1 confers commissural neuron identity on dorsal cells in the spinal cord

Commissural neurons in the spinal cord project their axons through the floor plate using a number of molecular interactions, such as netrins and their receptor DCC (deleted in colorectal cancer). However, the molecular cascades that control differentiation of commissural neurons are less characterized. A homeobox gene, MBH1 (mammalian BarH1) was expressed specifically in a subset of dorsal cells in the developing spinal cord. Transgenic mice that carried lacZ and MBH1-flanking genome sequences demonstrated that MBH1 was expressed by commissural neurons. To analyze the function of MBH1, we established an in vivo electroporation method for the transfer of DNA into the mouse spinal cord. Ectopic expression of MBH1 drove dorsal cells into the fate of commissural neurons with concomitant expression of TAG-1 (transiently expressed axonal surface glycoprotein 1) and DCC. Cells ectopically expressing MBH1 migrated to the deep dorsal horn, in which endogenous MBH1-positive cells accumulated. These results suggest that MBH1 functions upstream of TAG-1 and DCC and is involved in the fate determination of commissural neurons in the spinal cord.

The structure of the avian fast skeletal muscle troponin T gene: seven novel tandem-arranged exons in the exon x region

To elucidate the mechanism that produces enormous molecular diversity in troponin T (TnT) of fast skeletal muscle, we determined the 5'-half genomic sequence of the chicken fast muscle TnT gene. The sequence of ca. 16 kb included seven exons (exons 1, 2, 3, 4, w, 5, and 6), which have been reported previously and presumed by sequencing TnT cDNAs. Additionally we found six 15 nt and one 18 nt sequences in the region between exons 5 and 6 (i.e. the exon x region). They were encompassed by consensus splice donor and acceptor sites and preceded by putative branch sites, and designated herein as exons xa to xg. Our result shows that the sequence derived from exons x1, x2, and x3, the exons presumed previously by cDNA sequencing, is actually encoded by the seven exons xa to xg, establishing the precise gene structure in the exon x region. Based on our data, together with that on the 3'-half genomic sequence of the quail fast muscle TnT gene, we conclude that the avian fast skeletal muscle TnT gene includes 27 exons, 16 of which are alternatively spliced.

Natural occurrence of fast- and fast/slow-muscle chimeric fibers in the expression of troponin T isoforms

Rhomboideus, one of the back muscle tissues, and its single fibers were studied in chickens by immunostaining with antisera against fast- and slow-muscle-type troponin T isoforms. Nonuniform distribution of slow-muscle-type isoforms was for the first time detected in single fibers isolated from the muscle, although fast-muscle-type troponin T isoforms were distributed over the whole length of the fiber. Based on these observations, we conclude that fast- and fast/slow-muscle chimeric fibers exist in normal skeletal muscle tissue and that the existence of chimeric fibers is direct evidence showing that myonuclei subjected to different determination in troponin T isoform expression can together form a single muscle fiber.

Fructosamine in HbS and G6PD-deficient Saudi Arabs in the Eastern Province of Saudi Arabia

Plasma fructosamine, total proteins and albumin were estimated in a group of 77 sickle cell anaemia and 32 glucose-6-phosphate dehydrogenase (G6PD)-deficient Saudi Arabs and the results compared with those obtained in a group of 30 normal controls. The mean values of fructosamine in the sickle cell anaemia and G6PD-deficient patients were not statistically different from those of the controls. The mean values of the total proteins and albumin were also not significantly different from those of the normal group. It is concluded that fructosamine level is not affected by sickle cell anaemia and G6PD deficiency, and provides a useful tool for monitoring diabetic patients in regions with high prevalence of haemoglobinopathies and G6PD deficiency.

A comparative study of glycosylated haemoglobin level in the Arabian camel (Camelus dromedarius) during different seasons

1. The extent of haemoglobin glycosylation from 60 camels has been determined (4.39%) in blood samples drawn during winter. 2. Phosphate (9.45 mg/dl), DPG (2.9 mumol/ml) and glucose (138 mg/dl) levels were also recorded. 3. In addition the P50 at pH 7.4 was measured (22.8 Torrs). 4. The data obtained compared with human blood levels and with levels reported for camels during summer sampling. 5. Despite the fact that camels have higher blood glucose levels than humans, the extent of glycosylation is much less in camel blood than in human blood.

A study of the biochemical characteristics of NADP+ isocitrate dehydrogenase from the liver and kidney of the Arabian camel (Camelus dromedarius)

1. NADP+ isocitrate dehydrogenase was partially purified from camel liver and kidney by an FPLC. 2. The specific activity of the purified preparation from liver was 63.5 mumol/min/mg protein and from the kidney was similar, 58.7 mumol/min/mg protein. 3. The enzyme from the two sources were similar in their pH optimum (7.6), electrophoretic mobility and stability to thermal inactivation at 60 degrees C. 4. Heat inactivation was accelerated by oxidized glutathione and cystine and decreased by dithiothreitol, reduced glutathione and cysteine. 5. The molecular weight of the enzyme from both organs was estimated as 60,000 +/- 5000. 6. Divalent metal ions increased the activities of both enzymes, with maximum catalytic activity in the presence of Mn2+ ions.