A Novel Glutathione S-Transferase Gtt2 Class (VpGSTT2) Is Found in the Genome of the AHPND/EMS Vibrio parahaemolyticus Shrimp Pathogen

Glutathione S-transferases are a family of detoxifying enzymes that catalyze the conjugation of reduced glutathione (GSH) with different xenobiotic compounds using either Ser, Tyr, or Cys as a primary catalytic residue. We identified a novel GST in the genome of the shrimp pathogen V. parahaemolyticus FIM- S1708⁺, a bacterial strain associated with Acute Hepatopancreatic Necrosis Disease (AHPND)/Early Mortality Syndrome (EMS) in cultured shrimp. This new GST class was named Gtt2. It has an atypical catalytic mechanism in which a water molecule instead of Ser, Tyr, or Cys activates the sulfhydryl group of GSH. The biochemical properties of Gtt2 from Vibrio parahaemolyticus (VpGSTT2) were characterized using kinetic and crystallographic methods. Recombinant VpGSTT2 was enzymatically active using GSH and CDNB as substrates, with a specific activity of 5.7 units/mg. Low affinity for substrates was demonstrated using both Michaelis–Menten kinetics and isothermal titration calorimetry. The crystal structure showed a canonical two-domain structure comprising a glutathione binding G-domain and a hydrophobic ligand H domain. A water molecule was hydrogen-bonded to residues Thr9 and Ser 11, as reported for the yeast Gtt2, suggesting a primary role in the reaction. Molecular docking showed that GSH could bind at the G-site in the vicinity of Ser11. G-site mutationsT9A and S11A were analyzed. S11A retained 30% activity, while T9A/S11A showed no detectable activity. VpGSTT2 was the first bacterial Gtt2 characterized, in which residues Ser11 and Thr9 coordinated a water molecule as part of a catalytic mechanism that was characteristic of yeast GTT2. The GTT2 family has been shown to provide protection against metal toxicity; in some cases, excess heavy metals appear in shrimp ponds presenting AHPND/EMS. Further studies may address whether GTT2 in V. parahaemolyticus pathogenic strains may provide a competitive advantage as a novel detoxification mechanism.     

Dysregulated molecular networks in head and neck carcinogenesis

Multiple genetic and epigenetic events, including the aberrant expression and function of molecules regulating cell signaling, growth, survival, motility, angiogenesis, and cell cycle control, underlie the progressive acquisition of a malignant phenotype in squamous carcinomas of the head and neck (HNSCC). In this regard, there has been a recent explosion in our understanding on how extracellular components, cell surface molecules, and a myriad of intracellular proteins and second messenger systems interact with each other, and are organized in pathways and networks to control cellular and tissue functions and cell fate decisions. This emerging ability to understand the basic mechanism controlling inter- and intra-cellular communication has provided an unprecedented opportunity to understand how their dysregulation contributes to the growth and dissemination of human cancers. Here, we will discuss the emerging information on how the use of modern technologies, including gene array and proteomic studies, combined with the molecular dissection of aberrant signaling networks, including the EGFR, ras, NFkappaB, Stat, Wnt/beta-catenin, TGF-beta, and PI3K-AKT-mTOR signaling pathways, can help elucidate the molecular mechanisms underlying HNSCC progression. Ultimately, we can envision that this knowledge may provide tremendous opportunities for the diagnosis of premalignant squamous lesions, and for the development of novel molecular-targeted strategies for the prevention and treatment of HNSCC.     

Increasing adiposity in normal ovulatory women affects adipocytokine expression in subcutaneous and visceral abdominal fat

Objective

To determine which adipocytokines are differentially expressed as a function of body mass index (BMI), to compare expression of adipocytokines in abdominal subcutaneous and omental fat, and to correlate these findings with serum levels, BMI, and parameters of insulin resistance.

Methods

Serum and subcutaneous (sc) and omental (om) tissue were obtained from lean and obese ovulatory women undergoing gynecologic surgery. We determined adipocytokine expression in sc versus om abdominal fat and related this to increasing BMI.

Results

Serum leptin was higher and adiponectin lower in overweight subjects. Adipocytokines had higher expression in sc abdominal versus om adipose tissue with the most significant difference observed for leptin (P = 0.01). As BMI increased, sc leptin expression increased and adiponectin expression decreased. The leptin/adiponectin ratio correlated significantly with BMI (R = 0.84, P = 0.0001).

Conclusion

Increased adipocytokine expression correlates with BMI. Abdominal sc tissue has greater adipocytokine expression overall. The serum leptin/adiponectin ratio is highly correlated with BMI. These data may help in our understanding of how obesity affects women in a variety of ways.     

Multimodal Imaging Assisting the Early Diagnosis of Cat-Scratch Neuroretinitis

To describe how a multifocal fundus imaging system assisted the early diagnosis of cat scratch neuroretinitis in a case of a 27-year-old male with unilateral visual loss, neuroretinitis, and a peripapillary angiomatous lesion. Multimodal fundus imaging analysis was an essential contributor to the clinical diagnosis of cat scratch neuroretinitis during the early stage of the disease.     

JPEG and raw image files compared to direct measurement of the breast region

Purpose:To compare JPEG and RAW image file extensions to direct measurement of the breast region.Methods:Points were marked on the breasts and arms of 40 female volunteers. The joining of these points in each hemibody formed seven linear segments, one angular segment and one median segment common to both hemibodies. Volunteers were photographed in a standardized fashion and evaluated by three raters using the software Adobe Photoshop CS6^® and three image file extensions (RAW, high resolution JPEG and low resolution JPEG); values were compared to direct anthropometry.Results:All variables had interclass correlation coefficient higher than 0.8 (ICC>0.8). On average, all variables in all methods showed differences (p<0.05) when compared to direct measurement. A formula was created for each segment and each image file extension in comparison with the direct measurement.Conclusion:Measurements were similar among the correlated JPEG and RAW image file extensions but differed from the actual breast measurement obtained with a caliper.Key words: Photogrammetry, Anthropometry, Software, Breast     

The temporal effects of changes in in vitro fertilization culture media on the one-cell mouse embryo system

The one-cell mouse embryo system has previously been shown to be more sensitive than the two-cell system to mild changes in in vitro fertilization (IVF) culture media. To determine whether this greater sensitivity is related to the developmental stage or to the length of exposure, one-cell embryos were collected and cultured in control media (Ham's F-10, 282 mOsm/liter), in media of altered osmolality (260, 300, and 316 mOsm/liter), or in media containing Cidex diluted 1:100,000. The one-cell embryos were exposed to control or altered media in four patterns: control group—control medium for 96 hr; Group A—altered medium for the first 24 hr followed by control medium for 72 hr; Group B—control medium for the first 24 hr followed by altered medium for 72 hr; and Group C—control medium for the first 24 hr, altered medium for the next 24 hr, and control medium again for 48 hr. The percentage of embryos developing to blastocysts in Group A (exposed to adverse conditions only for the first 24 hr of culture) was significantly lower than in the control group under all conditions studied. In contrast, the percentage of blastocysts developing in Group B was significantly lower than in the control group only in medium of 315 mOsm/liter and was not different from that in controls under the other conditions studied. There was no difference between Group C and the control group. We conclude that the higher sensitivity of the one-cell system is an inherent property of the one-cell stage, as exposure of the embryo during this critical first 24-hr period proved to have the most profound consequences.