Multiple technology approach based on stable isotope ratio analysis, Fourier transform infrared spectrometry and thermogravimetric analysis to ensure the fungal origin of the chitosan

Chitosan is a natural polysaccharide which has been authorized for oenological practices for the treatment of musts and wines. This authorization is limited to chitosan of fungal origin while that of crustacean origin is prohibited. To guarantee its origin, a method based on the measurement of the stable isotope ratios (SIR) of carbon δ13C, nitrogen δ15N, oxygen δ18O and hydrogen δ2H of chitosan has been recently proposed without indicating the threshold authenticity limits of these parameters which, for the first time, were estimated in this paper. In addition, on part of the samples analysed through SIR, Fourier transform infrared spectrometry (FTIR) and thermogravimetric analysis (TGA) were performed as simple and rapid discrimination methods due to limited technological resources. Samples having δ13C values above -14.2‱ and below -125.1‱ can be considered as authentic fungal chitosan without needing to analyse other parameters. If the δ13C value falls between -25.1‱ and -24.9‱, it is necessary to proceed further with the evaluation of the parameter δ15N, which must be above +2.7‱. Samples having δ18O values lower than +25.3‱ can be considered as authentic fungal chitosan. The combination of maximum degradation temperatures (obtained using TGA) and peak areas of Amide I and NH2/Amide II (obtained using FTIR) also allows the discrimination between the two origins of the polysaccharide. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) based on TGA, FTIR and SIR data successfully distributed the tested samples into informative clusters. Therefore, we present the technologies described as part of a robust analytical strategy for the correct identification of chitosan samples from crustaceans or fung

Chitosan in wine industry: identification of origin by a multidisciplinary approach and application in oenology

Aim: Chitosan is a promising antimicrobial agent, capable of providing control of a wide range of spoilage microorganisms. To guarantee the fugal origin of chitosan, the only authorized for oenological practices, a multidisciplinary approach based on the measurement of the stable isotope ratios, Fourier transform infrared spectrometry and thermogravimetric analysis was proposed. In addition, the activity of chitosan against food related microorganisms was evaluated by different experiments aimed to discriminate between chemical and physical action of chitosan vs. the microorganisms. Method: The measurement of the stable isotope ratios (SIR) of carbon δ13C, nitrogen δ15N, oxygen δ18O and hydrogen δ2H of 35 samples of chitosan and the data of maximum degradation temperatures (obtained by TGA) combined with those of the peak areas of amide I and NH2/Amide II (obtained by FTIR) were employed to discriminate chitosan different sources (fungal grown on different substrates vs crustacean). The antimicrobial activity was tested in static and stirred conditions, in a synthetic media, using type strains of most common technological or spoilage microorganism. Viability was evaluated by Petri plate counts. The activity of the soluble portion of chitosan was checked by inoculating microorganisms in the media after chitosan removal. Results: The Kruskal-Wallis test showed that δ13C and δ18O were the most significant parameters able to classified chitosan into three different groups (from fungus grown on C3 photosynthetic cycle plant substrate, from fungus on C4 substrate and from crustacean). HCA and PCA analysis based on TGA, FTIR and SIR data successfully distributed the tested samples into informative clusters. Tests of chitosan antimicrobial activity highlighted the different sensitivity of microorganisms to chitosans, allowing selective control of spoilage agents. However, yeast and bacteria involved in fermentation were damaged by chitosan, and the synthetic media treated with this molecule showed a less fermentative aptitude. Conclusion: A robust analytical strategy for the correct identification of chitosan samples from crustaceans or fungi was presented, based on the observation that diverse biosynthetic pathways during the formation of the chitin influenced the isotopic composition of chitosan. Results of toxicity tests suggest that chitosan is a promising tool in fermented beverage production, but an in-depth study of the biochemical interaction between chitosan and food microorganisms is necessary

Bacterial survival under extreme UV radiation: A comparative proteomics study of Rhodobacter sp., isolated from high altitude wetlands in Chile

Salar de Huasco, defined as a polyextreme environment, is a high altitude saline wetland in the Chilean Altiplano (3800 m.a.s.l.), permanently exposed to the highest solar radiation doses registered in the world. We present here the first comparative proteomics study of a photoheterotrophic bacterium, Rhodobacter sp., isolated from this remote and hostile habitat. We developed an innovative experimental approach using different sources of radiation (in situ sunlight and UVB lamps), cut-off filters (Mylar, Lee filters) and a high-throughput, label-free quantitative proteomics method to comprehensively analyze the effect of seven spectral bands on protein regulation. A hierarchical cluster analysis (HCA) of 40 common proteins revealed that all conditions containing the most damaging UVB radiation induced similar pattern of protein regulation compared with UVA and visible light spectral bands. Moreover, it appeared that the cellular adaptation of Rhodobacter sp. to osmotic stress encountered in the hypersaline environment from which it was originally isolated, might further a higher resistance to damaging UV radiation. Indeed, proteins involved in the synthesis and transport of key osmoprotectants, such as glycine betaine and inositol, were found in very high abundance under UV radiation compared to the dark control, suggesting the function of osmolytes as efficient reactive oxygen scavengers. Our study also revealed a RecA-independent response and a tightly regulated network of protein quality control involving proteases and chaperones to selectively degrade misfolded and/or damaged proteins

Endometriosis and the Coronavirus (COVID-19) Pandemic: Clinical Advice and Future Considerations

The COVID-19 pandemic has led to a dramatic shift in the clinical practice of women’s health and routine care for endometriosis has been severely disrupted. Endometriosis is defined as an inflammatory disease characterized by lesions of endometrial-like tissue outside the uterus that is associated with pelvic pain and/or infertility (1). It affects ∼10% of reproductive age women worldwide, is diagnosed by surgical visualization or by radiological imaging, and is managed with hormone treatments or by laparoscopic removal of lesions (2–4). At the time of writing, under the guidance of international gynecological organizations (5–7), many centers temporarily ceased offering outpatient appointments, diagnostic imaging for nonacute pelvic pain, surgery for endometriosis, and fertility treatments. In the absence of routine care pathways and uncertainty about when health services will be available again, endometriosis sufferers are likely to feel vulnerable and that resultant stress and anxiety may contribute to a worsening of symptoms. The pandemic poses several important questions for healthcare providers on how best to deliver care within these restrictions. Herein, we present clinical advice on the management of endometriosis during the COVID-19 pandemic and future considerations

Comparison of minimally invasive surgical approaches for hysterectomy at a community hospital: robotic-assisted laparoscopic hysterectomy, laparoscopic-assisted vaginal hysterectomy and laparoscopic supracervical hysterectomy

The study reported here compares outcomes of three approaches to minimally invasive hysterectomy for benign indications, namely, robotic-assisted laparoscopic (RALH), laparoscopic-assisted vaginal (LAVH) and laparoscopic supracervical (LSH) hysterectomy. The total patient cohort comprised the first 237 patients undergoing robotic surgeries at our hospital between August 2007 and June 2009; the last 100 patients undergoing LAVH by the same surgeons between July 2006 and February 2008 and 165 patients undergoing LAVHs performed by nine surgeons between January 2008 and June 2009; 87 patients undergoing LSH by the same nine surgeons between January 2008 and June 2009. Among the RALH patients were cases of greater complexity: (1) higher prevalence of prior abdominopelvic surgery than that found among LAVH patients; (2) an increased number of procedures for endometriosis and pelvic reconstruction. Uterine weights also were greater in RALH patients [207.4 vs. 149.6 (LAVH; P < 0.001) and 141.1 g (LSH; P = 0.005)]. Despite case complexity, operative time was significantly lower in RALH than in LAVH (89.9 vs. 124.8 min, P < 0.001) and similar to that in LSH (89.6 min). Estimated blood loss was greater in LAVH (167.9 ml) than in RALH (59.0 ml, P < 0.001) or LSH (65.7 ml, P < 0.001). Length of hospital stay was shorter for RALH than for LAVH or LSH. Conversion and complication rates were low and similar across procedures. Multivariable regression indicated that LAVH, obesity, uterine weight ≥250 g and older age predicted significantly longer operative time. The learning curve for RALH demonstrated improved operative time over the case series. Our findings show the benefits of RALH over LAVH. Outcomes in RALH can be as good as or better than those in LSH, suggesting the latter should be the choice primarily for women desiring cervix-sparing surgery

Gynaecologists estimate and experience laparoscopic hysterectomy as more difficult compared with abdominal hysterectomy

The level of difficulty of various types of hysterectomy differs and may influence the choice of either approach. When surgeons consider one specific approach to hysterectomy as more difficult, they may be reluctant to perform this type of hysterectomy. The main objective of this study was to investigate the potential different levels of difficulty for laparoscopic and abdominal hysterectomy. Furthermore, the accuracy of estimating the level of difficulty was examined. In a randomized controlled trial between laparoscopic hysterectomy (LH) and abdominal hysterectomy (AH), gynaecologists were asked to record the preoperatively estimated and postoperatively experienced level of difficulty on a Visual Analogue Scale (VAS). Differences between LH and AH were examined and the correlation between the estimated uterine weight on bimanual palpation and the actual uterine weight was calculated. A difference on the VAS of three points or more (ΔVAS ≥ 3) was considered clinically relevant. In 72 out of 76 cases, both VAS scores were recorded. LH was estimated and experienced as significantly more difficult as compared with AH. In 13 (18%) cases, ΔVAS was ≥3, equally distributed between LH (n = 6) and AH (n = 7). Eleven of these 13 cases had a positive ΔVAS ≥3, meaning that surgery was experienced as more difficult than it was estimated. Surgeon’s estimation of uterine size correlated well with the actual uterine weight. LH is considered as more difficult than AH, which might be a reason for its slow implementation. In a large proportion of cases, gynaecologists seem to be able to estimate the level of difficulty of hysterectomy accurately

Chemical Basis of Prey Recognition in Thamnophiine Snakes: The Unexpected New Roles of Parvalbumins

Detecting and locating prey are key to predatory success within trophic chains. Predators use various signals through specialized visual, olfactory, auditory or tactile sensory systems to pinpoint their prey. Snakes chemically sense their prey through a highly developed auxiliary olfactory sense organ, the vomeronasal organ (VNO). In natricine snakes that are able to feed on land and water, the VNO plays a critical role in predatory behavior by detecting cues, known as vomodors, which are produced by their potential prey. However, the chemical nature of these cues remains unclear. Recently, we demonstrated that specific proteins–parvalbumins–present in the cutaneous mucus of the common frog (Rana temporaria) may be natural chemoattractive proteins for these snakes. Here, we show that parvalbumins and parvalbumin-like proteins, which are mainly intracellular, are physiologically present in the epidermal mucous cells and mucus of several frog and fish genera from both fresh and salt water. These proteins are located in many tissues and function as Ca2+ buffers. In addition, we clarified the intrinsic role of parvalbumins present in the cutaneous mucus of amphibians and fishes. We demonstrate that these Ca2+-binding proteins participate in innate bacterial defense mechanisms by means of calcium chelation. We show that these parvalbumins are chemoattractive for three different thamnophiine snakes, suggesting that these chemicals play a key role in their prey-recognition mechanism. Therefore, we suggest that recognition of parvalbumin-like proteins or other calcium-binding proteins by the VNO could be a generalized prey-recognition process in snakes. Detecting innate prey defense mechanism compounds may have driven the evolution of this predator-prey interaction

Twenty-first century laparoscopic hysterectomy: should we not leave the vaginal step out?

The objective of this study was to compare surgical outcomes for laparoscopically assisted vaginal hysterectomy (LAVH) with total laparoscopic hysterectomy (TLH) in three teaching hospitals in the Netherlands. This study is a multicenter cohort retrospective analysis of consecutive cases (Canadian Task Force classification II-2). One hundred and four women underwent a laparoscopic hysterectomy between March 1995 and March 2005 at one of three teaching hospitals. This included 37 women who underwent LAVH and 67 who underwent TLH. Blood loss, operating time, and intraoperative complications such as bladder or ureteric injury as well as conversion to an open procedure were recorded. In the TLH group, average age was statistically significant lower, as well as the mean parity, whereas estimated uterus size was statistically significant larger, compared to the LAVH group. Main indication in both groups was dysfunctional uterine bleeding. In the TLH group, mean blood loss (173 mL) was significant lower compared to the LAVH group (457 mL), whereas length of surgery, uterus weight, and complication rates were comparable between the two groups. The method of choice at the start of the study period was LAVH, and by the end of the study period, it had been superceded by TLH. LAVH should not be regarded as the novice’s laparoscopic hysterectomy. Moreover, with regard blood loss, TLH shows advantages above LAVH. This might be due to the influence of the altered anatomy in the vaginal stage of the LAVH procedure. Therefore, when a vaginal hysterectomy is contraindicated, TLH is the procedure of choice. LAVH remains indicated in case of vaginal hysterectomy with accompanying adnexal surgery

Clarifying the murk: unveiling bacterial dynamics in response to crude oil pollution, Corexit-dispersant, and natural sunlight in the Gulf of Mexico

The 2010 Deepwater Horizon (DwH) Oil spill released an enormous volume of oil into the Gulf of Mexico (GoM), prompting the widespread use of chemical dispersants like Corexit® EC9500A. The ecological consequences of this treatment, especially when combined with natural factors such as sunlight, remain unexplored in the context of marine bacterial communities’ dynamics. To address this knowledge gap, our study employed a unique metaproteomic approach, investigating the combined effects of sunlight, crude Macondo surrogate oil, and Corexit on GoM microbiome across different mesocosms. Exposure to oil and/or Corexit caused a marked change in community composition, with a decrease in taxonomic diversity relative to controls in only 24 hours. Hydrocarbon (HC) degraders, particularly those more tolerant to Corexit and phototoxic properties of crude oil and/or Corexit, proliferated at the expense of more sensitive taxa. Solar radiation exacerbated these effects in most taxa. We demonstrated that sunlight increased the dispersant’s toxicity, impacting on community structure and functioning. These functional changes were primarily directed by oxidative stress with upregulated proteins and enzymes involved in protein turnover, general stress response, DNA replication and repair, chromosome condensation, and cell division. These factors were more abundant in chemically treated conditions, especially in the presence of Corexit compared to controls. Oil treatment significantly enhanced the relative abundance of Alteromonas, an oil-degrading Gammaproteobacteria. In combined oil-Corexit treatments, the majority of identified protein functions were assigned to Alteromonas, with strongly expressed proteins involved in membrane transport, motility, carbon and amino acid metabolism and cellular defense mechanisms. Marinomonas, one of the most active genera in dark conditions, was absent from the light treatment. Numerous metabolic pathways and HC-degrading genes provided insights into bacterial community adaptation to oil spills. Key enzymes of the glyoxylate bypass, enriched in contaminant-containing treatments, were predominantly associated with Rhodobacterales and Alteromonadales. Several proteins related to outer membrane transport, photosynthesis, and nutrient metabolisms were characterized, allowing predictions of the various treatments on biogeochemical cycles. The study also presents novel perspectives for future oil spill clean-up processes

Protein structure, amino acid composition and sequence determine proteome vulnerability to oxidation-induced damage

Oxidative stress alters cell viability, from microorganism irradiation sensitivity to human aging and neurodegeneration. Deleterious effects of protein carbonylation by reactive oxygen species (ROS) make understanding molecular properties determining ROS susceptibility essential. The radiation‐resistant bacterium Deinococcus radiodurans accumulates less carbonylation than sensitive organisms, making it a key model for deciphering properties governing oxidative stress resistance. We integrated shotgun redox proteomics, structural systems biology, and machine learning to resolve properties determining protein damage by γ‐irradiation in Escherichia coli and D. radiodurans at multiple scales. Local accessibility, charge, and lysine enrichment accurately predict ROS susceptibility. Lysine, methionine, and cysteine usage also contribute to ROS resistance of the D. radiodurans proteome. Our model predicts proteome maintenance machinery, and proteins protecting against ROS are more resistant in D. radiodurans. Our findings substantiate that protein‐intrinsic protection impacts oxidative stress resistance, identifying causal molecular properties