Decision curve analysis confirms higher clinical utility of multi-domain versus single-domain prediction models in patients with open abdomen treatment for peritonitis.

BACKGROUND: Prediction modelling increasingly becomes an important risk assessment tool in perioperative systems approaches, e.g. in complex patients with open abdomen treatment for peritonitis. In this population, combining predictors from multiple medical domains (i.e. demographical, physiological and surgical variables) outperforms the prediction capabilities of single-domain prediction models. However, the benefit of these prediction models for clinical decision-making remains to be investigated. We therefore examined the clinical utility of mortality prediction models in patients suffering from peritonitis with a decision curve analysis. METHODS: In this secondary analysis of a large dataset, a traditional logistic regression approach, three machine learning methods and a stacked ensemble were employed to examine the predictive capability of demographic, physiological and surgical variables in predicting mortality under open abdomen treatment for peritonitis. Calibration was examined with calibration belts and predictive performance was assessed with the area both under the receiver operating characteristic curve (AUROC) and under the precision recall curve (AUPRC) and with the Brier Score. Clinical utility of the prediction models was examined by means of a decision curve analysis (DCA) within a treatment threshold range of interest of 0-30%, where threshold probabilities are traditionally defined as the minimum probability of disease at which further intervention would be warranted. RESULTS: Machine learning methods supported available evidence of a higher prediction performance of a multi- versus single-domain prediction models. Interestingly, their prediction performance was similar to a logistic regression model. The DCA demonstrated that the overall net benefit is largest for a multi-domain prediction model and that this benefit is larger compared to the default "treat all" strategy only for treatment threshold probabilities above about 10%. Importantly, the net benefit for low threshold probabilities is dominated by physiological predictors: surgical and demographics predictors provide only secondary decision-analytic benefit. CONCLUSIONS: DCA provides a valuable tool to compare single-domain and multi-domain prediction models and demonstrates overall higher decision-analytic value of the latter. Importantly, DCA provides a means to clinically differentiate the risks associated with each of these domains in more depth than with traditional performance metrics and highlighted the importance of physiological predictors for conservative intervention strategies for low treatment thresholds. Further, machine learning methods did not add significant benefit either in prediction performance or decision-analytic utility compared to logistic regression in these data.

Outcome in patients with open abdomen treatment for peritonitis: a multidomain approach outperforms single domain predictions.

Numerous patient-related clinical parameters and treatment-specific variables have been identified as causing or contributing to the severity of peritonitis. We postulated that a combination of clinical and surgical markers and scoring systems would outperform each of these predictors in isolation. To investigate this hypothesis, we developed a multivariable model to examine whether survival outcome can reliably be predicted in peritonitis patients treated with open abdomen. This single-center retrospective analysis used univariable and multivariable logistic regression modeling in combination with repeated random sub-sampling validation to examine the predictive capabilities of domain-specific predictors (i.e., demography, physiology, surgery). We analyzed data of 1,351 consecutive adult patients (55.7% male) who underwent open abdominal surgery in the study period (January 1998 to December 2018). Core variables included demographics, clinical scores, surgical indices and indicators of organ dysfunction, peritonitis index, incision type, fascia closure, wound healing, and fascial dehiscence. Postoperative complications were also added when available. A multidomain peritonitis prediction model (MPPM) was constructed to bridge the mortality predictions from individual domains (demographic, physiological and surgical). The MPPM is based on data of n = 597 patients, features high predictive capabilities (area under the receiver operating curve: 0.87 (0.85 to 0.90, 95% CI)) and is well calibrated. The surgical predictor "skin closure" was found to be the most important predictor of survival in our cohort, closely followed by the two physiological predictors SAPS-II and MPI. Marginal effects plots highlight the effect of individual outcomes on the prediction of survival outcome in patients undergoing staged laparotomies for treatment of peritonitis. Although most single indices exhibited moderate performance, we observed that the predictive performance was markedly increased when an integrative prediction model was applied. Our proposed MPPM integrative prediction model may outperform the predictive power of current models.

[Wound Healing Disorders after Excision and Open Treatment for Pilonidal Sinus]. / Wundheilungsstörungen nach Exzision und offener Behandlung eines Sinus pilonidalis.

INTRODUCTION: Pilonidalis sinus disease is a mostly chronic selective infection of the hairy skin in the area of skin wrinkles, mainly in the area of the natal cleft. Open treatment is still the most common recommended therapy. Nevertheless, there may be healing disorders within the framework of open wound treatment, which can significantly complicate the course. METHODS: The following is an overview of wound healing disorders after excision of pilonidalis sinus. Healing time and frequency are determined on the basis of current data and the causes of the healing disorder are evaluated. In addition, possible treatment options are presented and treatment recommendations are made. RESULTS: The evaluation of published data on wound healing period showed that the wound usually heals after a mean of two months. The results of the German forces cohort study show by way of example that almost all wounds have healed in the period up to three months. However, a small percentage of non-healing wounds remain. The frequency of significantly delayed wound healing is given in the literature as 2 - 5%. The influencing factors for wound healing after sinus pilonidalis excision are not only the size and symmetry of the excision wound but also other details of open wound treatment. In addition to intensification of the previous open wound treatment, the new excision and refreshment of the wound are mentioned as treatment options in the event of a lack of wound healing. Furthermore, changes in strategy for plastic-reconstructive procedures or other surface treatment are also recommended. CONCLUSION: The excision wound of pilonidalis sinus should be healed after three to four months at the latest, after which the wound can be regarded as a wound with significantly delayed healing or as a wound healing disorder. Around this time, the findings should be re-evaluated and, if necessary, a change in the treatment concept should be made.

Hybrid shallow on-axis and deep off-axis hydrothermal circulation at fast-spreading ridges.

Hydrothermal flow at oceanic spreading centres accounts for about ten per cent of all heat flux in the oceans and controls the thermal structure of young oceanic plates. It also influences ocean and crustal chemistry, provides a basis for chemosynthetic ecosystems, and has formed massive sulphide ore deposits throughout Earth's history. Despite this, how and under what conditions heat is extracted, in particular from the lower crust, remains largely unclear. Here we present high-resolution, whole-crust, two- and three-dimensional simulations of hydrothermal flow beneath fast-spreading ridges that predict the existence of two interacting flow components, controlled by different physical mechanisms, that merge above the melt lens to feed ridge-centred vent sites. Shallow on-axis flow structures develop owing to the thermodynamic properties of water, whereas deeper off-axis flow is strongly shaped by crustal permeability, particularly the brittle-ductile transition. About 60 per cent of the discharging fluid mass is replenished on-axis by warm (up to 300 degrees Celsius) recharge flow surrounding the hot thermal plumes, and the remaining 40 per cent or so occurs as colder and broader recharge up to several kilometres away from the axis that feeds hot (500-700 degrees Celsius) deep-rooted off-axis flow towards the ridge. Despite its lower contribution to the total mass flux, this deep off-axis flow carries about 70 per cent of the thermal energy released at the ridge axis. This combination of two flow components explains the seismically determined thermal structure of the crust and reconciles previously incompatible models favouring either shallower on-axis or deeper off-axis hydrothermal circulation.

Microbial metal-sulfide oxidation in inactive hydrothermal vent chimneys suggested by metagenomic and metaproteomic analyses.

Metal-sulfides are wide-spread in marine benthic habitats. At deep-sea hydrothermal vents, they occur as massive sulfide chimneys formed by mineral precipitation upon mixing of reduced vent fluids with cold oxygenated sea water. Although microorganisms inhabiting actively venting chimneys and utilizing compounds supplied by the venting fluids are well studied, only little is known about microorganisms inhabiting inactive chimneys. In this study, we combined 16S rRNA gene-based community profiling of sulfide chimneys from the Manus Basin (SW Pacific) with radiometric dating, metagenome (n = 4) and metaproteome (n = 1) analyses. Our results shed light on potential lifestyles of yet poorly characterized bacterial clades colonizing inactive chimneys. These include sulfate-reducing Nitrospirae and sulfide-oxidizing Gammaproteobacteria dominating most of the inactive chimney communities. Our phylogenetic analysis attributed the gammaproteobacterial clades to the recently described Woeseiaceae family and the SSr-clade found in marine sediments around the world. Metaproteomic data identified these Gammaproteobacteria as autotrophic sulfide-oxidizers potentially facilitating metal-sulfide dissolution via extracellular electron transfer. Considering the wide distribution of these gammaproteobacterial clades in marine environments such as hydrothermal vents and sediments, microbially accelerated neutrophilic mineral oxidation might be a globally relevant process in benthic element cycling and a considerable energy source for carbon fixation in marine benthic habitats.

[Pilonidal Sinus Disease; What is the Best Treatment Option?] / Sinus pilonidalis ­ was ist die beste chirurgische Therapie?

INTRODUCTION: Sinus pilonidalis is a chronic infection of the hairy skin in the area of skin wrinkles, with the most common localization in the natal cleft. The disease often has a significant impact on the quality of life of the affected person; the treatment may be complex and needs to be adapted to the patient's needs. METHODS: Below is an overview of the origin as well as the treatment alternatives and their peculiarities. The following aspects are presented: early post-operative results, wound healing disorder and long-term results. RESULTS: The pathomechanism of pilonidal sinus disease has still not been conclusively clarified; it must continue to be assumed that the hair in the natal cleft contributes significantly to the formation. However, recent findings indicate that the large tufts of hair that are repeatedly found in the wound cavity are most likely to come from the hairy scalp. Three essential treatment options can be distinguished: The standard treatment of excision and subsequent open wound treatment, has a low recurrence rate, but requires considerable effort in wound treatment and thus leads to protracted time off work. Relatively new treatments include locally destructive treatment that essentially preserves the skin. Important representatives are so-called pit picking, fistuloscopy and other forms of treatment, such as phenol injection and/or laser treatment. In these treatment options, the final evaluation of the results is still pending. The third treatment group is excision and plastic reconstruction. These procedures are technically demanding, often involve inpatient treatment but lead to relatively good results in the long term. CONCLUSION: Treatment of pilonidal disease requires patient-oriented therapy planning. The patient must be taught the different treatment options and a treatment recommendation must be given to the patient. Excision and open granulation continues to serve as a standard procedure with which other treatment options can be compared.

Accumulation of CD11c+CD163+ Adipose Tissue Macrophages through Upregulation of Intracellular 11ß-HSD1 in Human Obesity.

Adipose tissue (AT) macrophages (ATMs) are key players for regulation of AT homeostasis and obesity-related metabolic disorders. However, the phenotypes of human ATMs and regulatory mechanisms of their polarization have not been clearly described. In this study, we investigated human ATMs in both abdominal visceral AT and s.c. AT and proposed an 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1)-glucocorticoid receptor regulatory axis that might dictate M1/M2 polarization in ATMs. The accumulation of CD11c+CD163+ ATMs in both visceral AT and s.c. AT of obese individuals was confirmed at the cellular level and was found to be clearly correlated with body mass index and production of reactive oxygen species. Using our in vitro system where human peripheral blood monocytes (hPBMs) were cocultured with Simpson-Golabi-Behmel syndrome adipocytes, M1/M2 polarization was found to be dependent on 11ß-HSD1, an intracellular glucocorticoid reactivating enzyme. Exposure of hPBMs to cortisol-induced expression of CD163 and RU-486, a glucocorticoid receptor antagonist, significantly abrogated CD163 expression through coculture of mature adipocytes with hPBMs. Moreover, 11ß-HSD1 was expressed in crown ATMs in obese AT. Importantly, conditioned medium from coculture of adipocytes with hPBMs enhanced proliferation of human breast cancer MCF7 and MDA-MB-231 cells. In summary, the phenotypic switch of ATMs from M2 to mixed M1/M2 phenotype occurred through differentiation of adipocytes in obese individuals, and upregulation of intracellular 11ß-HSD1 might play a role in the process.

Surgical Treatment for Extramammary Paget's Disease.

OPINION STATEMENT: Extramammary Paget's disease (EMPD) is a rare, slow growing non-melanoma skin cancer.Diagnosis is often significantly delayed, since clinical presentation may resemble common benign dermatoses. Treatment is characterized by high recurrence rates. This is in part due to ill-defined margins and by frequent development of satellites. Improvement of outcome needs a better preoperative planning with fluorescence diagnostics or scouting biopsies. Mohs micrographic surgery has some advantages for patients, such as reduced relapse rates and prolonged relapse-free survival. Improved identification of Paget cells in cryosections by immunostainings or alternatively the use of delayed Mohs with formalin-fixed material reduces the rate of false-negative results. Surgery remains the cornerstone of treatment.

Angiogenesis: Managing the Culprits behind Tumorigenesis and Metastasis.

Deregulated angiogenesis has been identified as a key contributor in a number of pathological conditions including cancer. It is a complex process, which involves highly regulated interaction of multiple signalling molecules. The pro-angiogenic signalling molecule, vascular endothelial growth factor (VEGF) and its cognate receptor 2 (VEGFR-2), which is often highly expressed in majority of human cancers, plays a central role in tumour angiogenesis. Owing to the importance of tumour vasculature in carcinogenesis, tumour blood vessels have emerged as an excellent therapeutic target. The anti-angiogenic therapies have been shown to arrest growth of solid tumours through multiple mechanisms, halting the expansion of tumour vasculature and transient normalization of tumour vasculature which help in the improvement of blood flow resulting in more uniform delivery of cytotoxic agents to the core of tumour mass. This also helps in reduction of hypoxia and interstitial pressure leading to reduced chemotherapy resistance and more uniform delivery of cytotoxic agents at the targeted site. Thus, complimentary combination of different agents that target multiple molecules in the angiogenic cascade may optimize inhibition of angiogenesis and improve clinical benefit in the cancer patients. This review provides an update on the current trend in exploitation of angiogenesis pathways as a strategy in the treatment of cancer.

H1N1 vaccination in Sjögren's syndrome triggers polyclonal B cell activation and promotes autoantibody production.

OBJECTIVES: Vaccination of patients with rheumatic disease has been reported to result in lower antibody titres than in healthy individuals. However, studies primarily include patients on immunosuppressive therapy. Here, we investigated the immune response of treatment-naïve patients diagnosed with primary Sjögren's syndrome (pSS) to an H1N1 influenza vaccine. METHODS: Patients with Sjögren's syndrome without immunomodulatory treatment and age-matched and gender-matched healthy controls were immunised with an H1N1 influenza vaccine and monitored for serological and cellular immune responses. Clinical symptoms were monitored with a standardised form. IgG class switch and plasma cell differentiation were induced in vitro in purified naïve B cells of untreated and hydroxychloroquine-treated patients and healthy controls. Gene expression was assessed by NanoString technology. RESULTS: Surprisingly, treatment-naïve patients with Sjögren's syndrome developed higher H1N1 IgG titres of greater avidity than healthy controls on vaccination. Notably, off-target B cells were also triggered resulting in increased anti-EBV and autoantibody titres. Endosomal toll-like receptor activation of naïve B cells in vitro revealed a greater propensity of patient-derived cells to differentiate into plasmablasts and higher production of class switched IgG. The amplified plasma cell differentiation and class switch could be induced in cells from healthy donors by preincubation with type 1 interferon, but was abolished in hydroxychloroquine-treated patients and after in vitro exposure of naïve B cells to chloroquine. CONCLUSIONS: This comprehensive analysis of the immune response in autoimmune patients to exogenous stimulation identifies a mechanistic basis for the B cell hyperactivity in Sjögren's syndrome, and suggests that caution is warranted when considering vaccination in non-treated autoimmune patients.

Stubborn rectal prolapse in systemic sclerosis.

Systemic sclerosis (SSc) is an autoimmune connective tissue disorder. Anorectal involvement might typically cause fecal incontinence and rarely rectal prolapse. Here we report three female patients, who were admitted with a mean history of 10 years suffering from SSc. All patients presented with the initial symptom of anal incontinence, in all cases this was associated with rectal intussusception or rectal prolapse. The three women faced prolapse recurrence, independent of the initial procedure. After surgical removal of the prolapse, the incontinence remained. In SSc rectal prolapse syndrome might occur at an earlier age, and a primary prolapse of the ventral aspect of the rectal wall seems to be typical for this disease. If patients with prior diagnosis of SSc appear with third degree of fecal incontinence, it is suspected to be associated with rectal prolapse. The prolapse recurrence rate after surgery in SSc patients is high.

Stapled hemorrhoidopexy: functional results, recurrence rate, and prognostic factors in a single center analysis.

PURPOSE: Since its introduction, stapled hemorrhoidopexy (SHP), the so-called Longo procedure, became a widely accepted treatment option for prolapsing hemorrhoids. Nevertheless, from the early years, concerns grew about the early functional results and potential recurrences. In order to evaluate of SHP with special respect to early defecation disorders und recurrences, our single institute high-volume results were evaluated. METHOD: One thousand one hundred forty-four consecutive patients with SHP for prolapsing hemorrhoids were evaluated in a period from January 2007 to December 2013. In a prospective analysis, patients were followed with special respect to postoperative complications, functional disorders, mainly perianal irritation, stenosis, and recurrence. RESULTS: During the timeframe, a total of 663 men and 481 women were treated for prolapsing hemorrhoids. The mean age was 52.6 years (±14.4 years). Indication for surgery was prolapsing hemorrhoids in all cases. In addition to prolapse, 90 patients (7.9 %) suffered from bleeding, 96 patients (8.4 %) had itching, and 95 (8.3 %) had anal wetness; the mean operative time was 11 min (±4 min). Patients were treated as inpatients; the mean hospital stay was 3 days (±1 day). Early complications were observed in 14 patients (1.2 %). The follow-up revealed inflammatory reaction at the stapleline in 8 patients (0.7 %) and rectal stenosis in 22 cases (1.9 %), and recurrence was observed in 46 cases (4.0 %). CONCLUSION: The data presented here provide evidence that SHP is a save procedure with a very low rate for functional disorders and low recurrence rate. Therefore, in our hands, SHP remains standard for prolapsing hemorrhoids.

Deletion of WASp and N-WASp in B cells cripples the germinal center response and results in production of IgM autoantibodies.

Humoral immunodeficiency caused by mutations in the Wiskott-Aldrich syndrome protein (WASp) is associated with failure to respond to common pathogens and high frequency of autoimmunity. Here we addressed the question how deficiency in WASp and the homologous protein N-WASp skews the immune response towards autoreactivity. Mice devoid of WASp or both WASp and N-WASp in B cells formed germinal center to increased load of apoptotic cells as a source of autoantigens. However, the germinal centers showed abolished polarity and B cells retained longer and proliferated less in the germinal centers. While WASp-deficient mice had high titers of autoreactive IgG, B cells devoid of both WASp and N-WASp produced mainly IgM autoantibodies with broad reactivity to autoantigens. Moreover, B cells lacking both WASp and N-WASp induced somatic hypermutation at reduced frequency. Despite this, IgG1-expressing B cells devoid of WASp and N-WASp acquired a specific high affinity mutation, implying an increased BCR signaling threshold for selection in germinal centers. Our data provides evidence for that N-WASp expression alone drives WASp-deficient B cells towards autoimmunity.

Impact of prolapse mass on Contour Transtar technique for third-degree rectal prolapse.

PURPOSE: Contour Transtar procedure for rectal prolapse is a promising technique according to safety and efficacy. One potential surgical problem is failure of the stapler due to the thick rectal wall. In order to evaluate the practicability and the impending limitations of the Contour Transtar technique, we reviewed our data with special respect to the necessity of additional anastomosis suturing. METHODS: A prospective analysis of 25 consecutive patients, which underwent Contour Transtar procedure from January 2009 to July 2012, was performed. For statistic analysis, the groups with and without additional suturing of the anastomosis were evaluated according to patient characteristics and surgical outcome. RESULTS: Twenty-five patients, three men and 22 women, underwent transanal Contour Transtar stapling procedure for rectal prolapse. Due to stapling failure, additional suturing of the anastomosis was necessary in 4 of 25 procedures (16%). Age (74.1 vs. 83.1 years) and body mass index (30.8 vs. 22.7 kg/m(2)) were significantly different with and without additional suturing. Operative time was longer (62 vs. 31 min), more cartridges were used (12 vs. 6), and the specimen weight was higher (220 vs. 107 g) in patients with additional suturing. Early postoperative complications were observed in two patients without anastomosis suturing including one patient with bleeding and systemic inflammatory reaction in one case. Postoperative stay did not differ between both groups. CONCLUSION: Patients with extensive obesity, which present with a substantial rectal prolapse, may need additional suturing of the rectal anastomosis after Contour Transtar stapling. This causes prolonged operative time. However, this does not correlate with complications and it is not related to significant longer hospital stay.

Prevalence of Fecal Incontinence in Normal Pressure Hydrocephalus: A Prospective Evaluation of 100 Patients.

BACKGROUND: Normal pressure hydrocephalus (NPH) is a frequent disease in elderly patients. The main symptoms are gait disturbance, urine incontinence, and cognitive decline. Fecal urgency and incontinence are described as rare additional symptoms; however, no exact numbers are known. The aim of this study was to investigate the prevalence of fecal disturbances in NPH patients. METHODS: Patients who presented to our department with confirmed diagnosis of NPH between January and December 2021 were interviewed prospectively about fecal function. Additionally, the extent of gait disturbance, cognitive decline, ventriculomegaly (EvansIndex), disproportionate enlarged subarachnoid space hydrocephalus (DESH presence), age, gender, and length of history were documented. In those who were operated with a hydrocephalus shunt postoperative development of stool incontinence was followed up. RESULTS: One hundred patients were evaluated (67 males, 33 females, medium age 77.5 years, medium Evans Index: 0.37; 87 with disproportionate enlarged subarachnoid space hydrocephalus). 97 patients showed gait disturbance, 84 cognitive decline, and 87 bladder dysfunctions. 78 patients had the complete Hakim triad. 32 patients complained about fecal incontinence (20 with urge incontinence, 12 with complete incontinence). Twenty nine patients were shunted, of which 17 (57%) recovered completely, 9 (31%) partially, and 3 (10%) did not show any change. CONCLUSIONS: Fecal urgency and incontinence is a frequent finding in NPH (32%) and is essential for the quality of life. In the general population, fecal incontinence in elderly is found in up to 15%. The more than two-fold higher prevalence in NPH patients and the high percentage of postshunted improvement suggests that NPH causes often directly fecal disturbance.

A novel GPI-anchored dominant-negative TGF-ß receptor II renders T cells unresponsive to TGF-ß signaling.

Transforming growth factor ß (TGF-ß) is a pleiotropic cytokine expressed by a wide range of cell types and is known for hampering the effectiveness of cancer immune cell therapeutic approaches. We have designed a novel construct containing the extracellular domain of the TGF-ß receptor II linked to a glycosylphosphatidylinositol (GPI) anchor (GPI-ecto-TßRII) lacking the transmembrane and cytoplasmic signaling domain of TGF-ß receptor II (TßRII). T cells transduced with lentivirus expressing the GPI-ecto-TßRII construct show 5 to 15 times higher membrane expression compared with a previously established dominant-negative receptor carrying a truncated signaling domain. GPI-ecto-TßRII expression renders T cells unresponsive to TGF-ß-induced signaling seen by a lack of SMAD phosphorylation upon exogeneous TGF-ß treatment. Transduced T cells continue to express high levels of IFNγ and granulocyte-macrophage colony-stimulating factor (GM-CSF), among other cytokines, in the presence of TGF-ß while cytokine expression in untransduced T cells is being markedly suppressed. Furthermore, T cells expressing GPI-ecto-TßRII constructs have been shown to efficiently capture and inactivate TGF-ß from their environment. These results indicate the potential benefits of GPI-ecto-TßRII expressing cytotoxic T cells (CTLs) in future cell therapies.

Microbial ecosystem assessment and hydrogen oxidation potential of newly discovered vent systems from the Central and South-East Indian Ridge.

In order to expand the knowledge of microbial ecosystems from deep-sea hydrothermal vent systems located on the Central and South-East Indian Ridge, we sampled hydrothermal fluids, massive sulfides, ambient water and sediments of six distinct vent fields. Most of these vent sites were only recently discovered in the course of the German exploration program for massive sulfide deposits and no previous studies of the respective microbial communities exist. Apart from typically vent-associated chemosynthetic members of the orders Campylobacterales, Mariprofundales, and Thiomicrospirales, high numbers of uncultured and unspecified Bacteria were identified via 16S rRNA gene analyses in hydrothermal fluid and massive sulfide samples. The sampled sediments however, were characterized by an overall lack of chemosynthetic Bacteria and the presence of high proportions of low abundant bacterial groups. The archaeal communities were generally less diverse and mostly dominated by members of Nitrosopumilales and Woesearchaeales, partly exhibiting high proportions of unassigned Archaea. Correlations with environmental parameters were primarily observed for sediment communities and for microbial species (associated with the nitrogen cycle) in samples from a recently identified vent field, which was geochemically distinct from all other sampled sites. Enrichment cultures of diffuse fluids demonstrated a great potential for hydrogen oxidation coupled to the reduction of various electron-acceptors with high abundances of Hydrogenovibrio and Sulfurimonas species. Overall, given the large number of currently uncultured and unspecified microorganisms identified in the vent communities, their respective metabolic traits, ecosystem functions and mediated biogeochemical processes have still to be resolved for estimating consequences of potential environmental disturbances by future mining activities.

Taxonomic diversity of microbial communities in sub-seafloor hydrothermal sediments of the active Santorini-Kolumbo volcanic field.

Introduction: Active hydrothermal vents of volcanic origin provide a remarkable manifestation of life on Earth under extreme conditions, which may have consequences for our understanding of habitability on other terrestrial bodies as well. Methods: Here, we performed for the first time Illumina sequencing of bacterial and archaeal communities on sub-seafloor samples collected from the Santorini-Kolumbo volcanic field. A total of 19 (3-m long) gravity corers were collected and processed for microbial community analysis. Results: From a total of 6,46,671 produced V4 sequences for all samples, a total of 10,496 different Operational Taxonomic Units (OTUs) were identified that were assigned to 40 bacterial and 9 archaeal phyla and 14 candidate divisions. On average, the most abundant phyla in all samples were Chloroflexi (Chloroflexota) (24.62%), followed by Proteobacteria (Pseudomonadota) (11.29%), Firmicutes (Bacillota) (10.73%), Crenarchaeota (Thermoproteota) (8.55%), and Acidobacteria (Acidobacteriota) (8.07%). At the genus level, a total of 286 known genera and candidate genera were mostly dominated by members of Bacillus, Thermoflexus, Desulfatiglans, Pseudoalteromonas, and Pseudomonas. Discussion: In most of the stations, the Chao1 values at the deeper layers were comparable to the surface sediment samples denoting the high diversity in the subsurface of these ecosystems. Heatmap analysis based on the 100 most abundant OTUs, grouped the sampling stations according to their geographical location, placing together the two hottest stations (up to 99°C). This result indicates that this specific area within the active Kolumbo crater create a distinct niche, where microorganisms with adaptation strategies to withstand heat stresses can thrive, such as the endospore-forming Firmicutes.

The role of tetraspanin CD63 in antigen presentation via MHC class II.

Interactions between MHC class II (MHC II)-positive APCs and CD4(+) T cells are central to adaptive immune responses. Using an Epstein-Barr virus (EBV)-transformed B lymphoblastoid cell line (LCL) as MHC II-positive APCs and CD4(+) T-cell clones specific for two endogenously expressed EBV antigens, we found that shRNA knockdown of the tetraspanin protein CD63 in LCL cells consistently led to increased CD4(+) T-cell recognition. This effect was not due to enhanced antigen processing nor to changes in MHC II expression since CD63 knockdown did not influence the amount or dimerization of MHC II in LCL cells. We therefore investigated the possible involvement of exosomes, small MHC II- and tetraspanin-abundant vesicles which are secreted by LCL cells and which we found could themselves activate the CD4(+) T-cell clones in an MHC II-dependent manner. While equal loadings of exosomes purified from the control and CD63(low) LCLs stimulated T cells to a comparable degree, we found that exosome production significantly increased following CD63-knockdown, suggesting that this may underlie the greater T-cell stimulatory capacity of the CD63(low) LCLs. Taken together, our data reveal a new insight into the mechanisms by which tetraspanins are involved in the regulation of MHC II-dependent T-cell stimulation.

Laparoscopic assisted sigmoid resection for diverticular disease.

PURPOSE: Laparoscopic assisted sigmoid resection (LASR) has become a widely accepted procedure in colorectal surgery. In the last decade, numerous variations of surgical details have been established. In order to demonstrate a feasible technique, this video is provided. METHODS: LASR is performed using four ports. The first port is inserted via open access by a minilaparotomy in the right paraumbilical region. Two ports are sited in the right lower abdomen, including one 12-mm port in the following incision above the pubic symphysis. The forth port is inserted in the left upper abdomen. The procedure starts with the removal of adhesions, the peritoneal incision is performed medially, and a medial to lateral approach to the mesocolon and the inferior mesenteric artery (IMA) is carried out. After identifying the left ureter, the IMA is either clipped or sealed about 1.5 to 2 cm from the origin in order to preserve the autonomous plexus. Then dissection is continued on Gerota's fascia. After lifting the rectosigmoid, dissection is continued in the avascular plane until the mesentery of the upper rectum is mobilized. Then the remaining lateral adhesions are dissected with preservation of the gonadal vessels and the left ureter. The distal resection line is always in the upper rectum, which is easily identified by the lack of tenia. After sealing the mesorectum, the rectum is dissected using a linear stapler. Thereafter, a minilaparotomy above the pubic symphysis is performed and a device for protection and retraction of the wound is inserted. Dissection of the mesosigmoid and the descending colon is carried out extracorporally. The anvil of a circular stapling device is inserted in the descending colon, which is then returned into the peritoneal cavity. Running sutures closes the incision, and the anastomosis is carried out laparoscopically in a "double stapling" technique. CONCLUSION: The video describes the efficacy and technical feasibility of laparoscopic surgery for diverticular disease and demonstrates its effect regarding perioperative morbidity and functional outcome.