Morphological and proteomic analysis of biofilms from the Antarctic archaeon, Halorubrum lacusprofundi

Biofilms enhance rates of gene exchange, access to specific nutrients, and cell survivability. Haloarchaea in Deep Lake, Antarctica, are characterized by high rates of intergenera gene exchange, metabolic specialization that promotes niche adaptation, and are exposed to high levels of UV-irradiation in summer. Halorubrum lacusprofundi from Deep Lake has previously been reported to form biofilms. Here we defined growth conditions that promoted the formation of biofilms and used microscopy and enzymatic digestion of extracellular material to characterize biofilm structures. Extracellular DNA was found to be critical to biofilms, with cell surface proteins and quorum sensing also implicated in biofilm formation. Quantitative proteomics was used to define pathways and cellular processes involved in forming biofilms; these included enhanced purine synthesis and specific cell surface proteins involved in DNA metabolism; post-translational modification of cell surface proteins; specific pathways of carbon metabolism involving acetyl-CoA; and specific responses to oxidative stress. The study provides a new level of understanding about the molecular mechanisms involved in biofilm formation of this important member of the Deep Lake community.

Novel methylene blue staining technique for localizing small esophageal leiomyomas during thoracoscopic enucleation

The treatment of choice for leiomyoma, the most common benign esophageal tumor, is thoracoscopic enucleation. One of the most difficult aspects of thoracoscopic enucleation is the precise localization of small tumors (≤1.5 cm) and tumors without external protrusion. No simple, feasible solutions to this problem are available. We developed a novel methylene blue staining technique to localize small esophageal leiomyomas and evaluated the feasibility of our technique. Between January 2013 and July 2014, eight patients with small esophageal leiomyomas (≤1.5 cm) underwent thoracoscopic enucleation in Tongji Hospital. Preoperative endoscopic ultrasonography was performed in all patients. The leiomyomas were located in the middle (n = 5) and lower (n = 3) thirds of the esophagus. We preoperatively injected 0.5-1.0 mL methylene blue in the submucosa adjacent to the tumors under standard gastroscope guidance. The entire staining process took about 10 minutes. Staining was successful in all patients. The unstained tumor was exposed after the blue-stained mediastinal pleura, and overlying muscle were incised longitudinally. All procedures were successfully completed without conversion to open surgery. No abnormalities were detected in the esophageal mucosa. The median operating time was 60 minutes (range, 40-90 minutes). Postoperative histopathology confirmed leiomyoma in all patients. The median postoperative hospital stay was 6 days (range, 5-7 days). No major complications, such as esophageal leakage or esophageal diverticulum, occurred. Endoscopic methylene blue staining is safe and feasible for localizing small esophageal leiomyomas during thoracoscopic enucleation. This method will enable precise and easy enucleation.

Developing a genetic manipulation system for the Antarctic archaeon, Halorubrum lacusprofundi: investigating acetamidase gene function

No systems have been reported for genetic manipulation of cold-adapted Archaea. Halorubrum lacusprofundi is an important member of Deep Lake, Antarctica (~10% of the population), and is amendable to laboratory cultivation. Here we report the development of a shuttle-vector and targeted gene-knockout system for this species. To investigate the function of acetamidase/formamidase genes, a class of genes not experimentally studied in Archaea, the acetamidase gene, amd3, was disrupted. The wild-type grew on acetamide as a sole source of carbon and nitrogen, but the mutant did not. Acetamidase/formamidase genes were found to form three distinct clades within a broad distribution of Archaea and Bacteria. Genes were present within lineages characterized by aerobic growth in low nutrient environments (e.g. haloarchaea, Starkeya) but absent from lineages containing anaerobes or facultative anaerobes (e.g. methanogens, Epsilonproteobacteria) or parasites of animals and plants (e.g. Chlamydiae). While acetamide is not a well characterized natural substrate, the build-up of plastic pollutants in the environment provides a potential source of introduced acetamide. In view of the extent and pattern of distribution of acetamidase/formamidase sequences within Archaea and Bacteria, we speculate that acetamide from plastics may promote the selection of amd/fmd genes in an increasing number of environmental microorganisms.

Risperidone-induced topological alterations of anatomical brain network in first-episode drug-naive schizophrenia patients: a longitudinal diffusion tensor imaging study

BACKGROUND

It remains unclear whether the topological deficits of the white matter network documented in cross-sectional studies of chronic schizophrenia patients are due to chronic illness or to other factors such as antipsychotic treatment effects. To answer this question, we evaluated the white matter network in medication-naive first-episode schizophrenia patients (FESP) before and after a course of treatment.

METHOD

We performed a longitudinal diffusion tensor imaging study in 42 drug-naive FESP at baseline and then after 8 weeks of risperidone monotherapy, and compared them with 38 healthy volunteers. Graph theory was utilized to calculate the topological characteristics of brain anatomical network. Patients' clinical state was evaluated using the Positive and Negative Syndrome Scale (PANSS) before and after treatment.

RESULTS

Pretreatment, patients had relatively intact overall topological organizations, and deficient nodal topological properties primarily in prefrontal gyrus and limbic system components such as the bilateral anterior and posterior cingulate. Treatment with risperidone normalized topological parameters in the limbic system, and the enhancement positively correlated with the reduction in PANSS-positive symptoms. Prefrontal topological impairments persisted following treatment and negative symptoms did not improve.

CONCLUSIONS

During the early phase of antipsychotic medication treatment there are region-specific alterations in white matter topological measures. Limbic white matter topological dysfunction improves with positive symptom reduction. Prefrontal deficits and negative symptoms are unresponsive to medication intervention, and prefrontal deficits are potential trait biomarkers and targets for negative symptom treatment development.

NKD2 a novel marker to study the progression of osteosarcoma development

OBJECTIVE

Osteosarcoma is the most frequent metastatic bone tumor in the current era. An effective novel marker is essential at the current scenario for the identification of the tumor and to treat them in the early stage of osteosarcoma.

PATIENTS AND METHODS

In the present study, patients having metastatic and non-metastatic osteosarcoma samples were collected from the 23 patients along with the control. Microarray analysis was performed on both samples. The results were validated using Western blot analysis.

RESULTS

Microarray analysis confirms the up-regulation of NKD2 gene in the progression of osteosarcoma development. The results were validated using western blot analysis. Microarray in accordance with Western blot analysis helps to validate the expression of NKD2 in the progression of osteosarcoma development.

CONCLUSIONS

In short, NKD2 is the key molecular marker to study the progression of osteosarcoma development, and it may be used for better prognosis of the disease in early stage.

Dysregulation of Hypothalamo-Pituitary-Adrenocortical Axis in Overweight Female Diabetic Subjects is Associated with Downregulation of Corticosteroid Receptors and 11β-HSD1 in the Brain

The objective of this work was to assess hypothalamo-pituitary-adrenocortical (HPA) axis dysregulation in overweight diabetic women and investigate the possible mechanism using overweight diabetic rats. Twenty-two overweight diabetic women were recruited alongside 34 lean and 23 overweight healthy women serving as controls. Dexamethasone suppression test (0.25 mg DST) and low dose adrenocorticotropic hormone (ACTH) stimulation assay were used to evaluate the HPA axis activity. Then, high fat diet (HF) and STZ-induced diabetic rats were utilized to investigate the possible mechanism. After measurement of corticosterone circadian patterns and dexamethasone suppression levels, mRNA amounts of mineralocorticoid receptors (MR), glucocorticoid receptors (GR), and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) were determined by real time PCR at hippocampus, hypothalamus, and pituitary levels. Overweight diabetic women showed impaired HPA axis with negative feedback efficacy (suppression ratio F-DEX%: 0.52±0.06% vs. 0.49±0.06% vs. 0.14±0.08%), as well as increased adrenal cortisol secretion response to low dose ACTH stimulation. Interestingly, F-DEX% was negatively correlated with BMI (r=- 0.323, p=0.003), waist circumference (r=- 0.319, p=0.004), and HbA1c (r=- 0.334, p=0.002). Stepwise linear regression analysis showed F-DEX% was significantly related to HbA1c level (β=- 0.328, p=0.007) after adjusting for other covariates (age, BMI, waist circumference, SBP, TC, TG, and HOMA-IR). Furthermore, 11β-HSD1, MR, and GR mRNA expression levels were reduced at pituitary level while GR expression was downregulated at hippocampus level in HF and HF+STZ rats. In conclusion, hyperactive HPA axis in overweight diabetic subjects may be associated with downregulation of 11β-HSD1, MR, and GR in the brain.