Towards a tailored approach for patients with acute diverticulitis and abscess formation. The DivAbsc2023 multicentre case-control study.

BACKGROUND: This multicentre case-control study aimed to identify risk factors associated with non-operative treatment failure for patients with CT scan Hinchey Ib-IIb and WSES Ib-IIa diverticular abscesses. METHODS: This study included a cohort of adult patients experiencing their first episode of CT-diagnosed diverticular abscess, all of whom underwent initial non-operative treatment comprising either antibiotics alone or in combination with percutaneous drainage. The cohort was stratified based on the outcome of non-operative treatment, specifically identifying those who required emergency surgical intervention as cases of treatment failure. Multivariable logistic regression analysis to identify independent risk factors associated with the failure of non-operative treatment was employed. RESULTS: Failure of conservative treatment occurred for 116 patients (27.04%). CT scan Hinchey classification IIb (aOR 2.54, 95%CI 1.61;4.01, P < 0.01), tobacco smoking (aOR 2.01, 95%CI 1.24;3.25, P < 0.01), and presence of air bubbles inside the abscess (aOR 1.59, 95%CI 1.00;2.52, P = 0.04) were independent predictors of failure. In the subgroup of patients with abscesses > 5 cm, percutaneous drainage was not associated with the risk of failure or success of the non-operative treatment (aOR 2.78, 95%CI - 0.66;3.70, P = 0.23). CONCLUSIONS: Non-operative treatment is generally effective for diverticular abscesses. Tobacco smoking's role as an independent risk factor for treatment failure underscores the need for targeted behavioural interventions in diverticular disease management. IIb Hinchey diverticulitis patients, particularly young smokers, require vigilant monitoring due to increased risks of treatment failure and septic progression. Further research into the efficacy of image-guided percutaneous drainage should involve randomized, multicentre studies focussing on homogeneous patient groups.

A Study of Alternative TrkA Splicing Identifies TrkAIII as a Novel Potentially Targetable Participant in PitNET Progression.

Pituitary neuroendocrine tumors (PitNETs) are generally benign but comprise an aggressive, invasive, therapy-resistant, metastatic subset, underpinning a need for novel therapeutic targets. PitNETs exhibit low mutation rates but are associated with conditions linked to alternative splicing, an alternative oncogene pathway activation mechanism. PitNETs express the neurotrophin receptor TrkA, which exhibits oncogenic alternative TrkAIII splicing in other neuroendocrine tumors. We, therefore, assessed whether TrkAIII splicing represents a potential oncogenic participant in PitNETs. TrkAIII splicing was RT-PCR assessed in 53 PitNETs and TrkA isoform(s) expression and activation were assessed by confocal immunofluorescence. TrkAIII splicing was also compared to HIF1α, HIF2α, SF3B1, SRSF2, U2AF1, and JCPyV large T antigen mRNA expression, Xbp1 splicing, and SF3B1 mutation. TrkAIII splicing was detected in all invasive and most non-invasive PitNETs and was significantly elevated in invasive cases. In PitNET lineages, TrkAIII splicing was significantly elevated in invasive PIT1 PitNETs and high in invasive and non-invasive SF1 and TPIT lineages. Immunoreactivity consistent with TrkAIII activation characterized PitNET expressing TrkAIII mRNA, and invasive Pit1 PitNETs exhibited elevated HIF2α expression. TrkAIII splicing did not associate with SF3B1 mutations, altered SF3B1, SRSF2, and U2AF1 or JCPyV large T antigen expression, or Xbp1 splicing. Therefore, TrkAIII splicing is common in PitNETs, is elevated in invasive, especially PIT1 tumors, can result in intracellular TrkAIII activation, and may involve hypoxia. The data support a role for TrkAIII splicing in PitNET pathogenesis and progression and identify TrkAIII as a novel potential target in refractory PitNETs.

30-day Morbidity and Mortality after Cholecystectomy for Benign Gallbladder Disease (AMBROSE): A Prospective, International Collaborative Cohort Study.

OBJECTIVE: This study aimed to assess 30-day morbidity and mortality rates following cholecystectomy for benign gallbladder disease and identify the factors associated with complications. SUMMARY BACKGROUND DATA: Although cholecystectomy is common for benign gallbladder disease, there is a gap in the knowledge of the current practice and variations on a global level. METHODS: A prospective, international, observational collaborative cohort study of consecutive patients undergoing cholecystectomy for benign gallbladder disease from participating hospitals in 57 countries between January 1 and June 30, 2022, was performed. Univariate and multivariate logistic regression models were used to identify preoperative and operative variables associated with 30-day postoperative outcomes. RESULTS: Data of 21,706 surgical patients from 57 countries were included in the analysis. A total of 10,821 (49.9%), 4,263 (19.7%), and 6,622 (30.5%) cholecystectomies were performed in the elective, emergency, and delayed settings, respectively. Thirty-day postoperative complications were observed in 1,738 patients (8.0%), including mortality in 83 patients (0.4%). Bile leaks (Strasberg grade A) were reported in 278 (1.3%) patients and severe bile duct injuries (Strasberg grades B-E) were reported in 48 (0.2%) patients. Patient age, ASA physical status class, surgical setting, operative approach and Nassar operative difficulty grade were identified as the five predictors demonstrating the highest relative importance in predicting postoperative complications. CONCLUSION: This multinational observational collaborative cohort study presents a comprehensive report of the current practices and outcomes of cholecystectomy for benign gallbladder disease. Ongoing global collaborative evaluations and initiatives are needed to promote quality assurance and improvement in cholecystectomy.

Roux-en-Y Gastric Bypass after Laparoscopic Sleeve Gastrectomy Failure: Could the Number of Previous Operations Influence the Outcome?

After a failed laparoscopic adjustable gastric band (LAGB), laparoscopic sleeve gastrectomy (LSG) has been proposed as revisional surgery. Those patients that receive a second restrictive procedure fall into a small subgroup of patients with more than one restrictive procedure (MRP). If also the second restrictive procedure fails, the correct surgical strategy is a challenge for the surgeon. Roux-en-Y gastric bypass (RYGB) may be an option but there is no evidence in the literature on whether the procedure is effective in treating failures after MRP. This study aims to evaluate the influence of the previous number of restrictive interventions (MRP vs single LSG) in the results of RYGB as revisional surgery. We have retrospectively analyzed patients who underwent conversion from laparoscopic sleeve gastrectomy (LSG), or from multiple restrictive procedures (MRP), to RYGB for weight regain (WR) or insufficient weight loss (IWL) between 2009 and 2019. The number of patients analyzed was 69 with conversion to RYGB after LSG and 44 after MRP. The reduction of excess weight (%TWL) at 3, 6, 12, 24 RYGB postoperative months was respectively of 11.03%, 16.39%, 21.43%, and 24.22% in the MRP group, and of 10.97%, 16.4%, 21.22%, and 22.71% in the LSG group. No significant difference was found in %TWL terms after RYGB for the MRP group and the LSG group with an overall %TWL, which was 11.00 ± 6.03, 16.40 ± 8.08, 21.30 ± 9.43, and 23.30 ± 9.91 respectively at 3, 6, 12, and 24 months. The linear regression model highlighted a positive relationship between the %EWL post-bypass at 24 months and the time elapsed only between the LSG and RYGB in the MRP group patients (p < 0.001). RYGB has proved to be a reliable technique with good results in terms of weight loss after failed bariatric surgery both in patients who previously underwent MRP and in those who underwent exclusively LSG. RYGB showed better results in patients who experienced WR than in those who had IWL from previous techniques.

Abdominal drainage after elective colorectal surgery: propensity score-matched retrospective analysis of an Italian cohort.

BACKGROUND: In Italy, surgeons continue to drain the abdominal cavity in more than 50 per cent of patients after colorectal resection. The aim of this study was to evaluate the impact of abdominal drain placement on early adverse events in patients undergoing elective colorectal surgery. METHODS: A database was retrospectively analysed through a 1:1 propensity score-matching model including 21 covariates. The primary endpoint was the postoperative duration of stay, and the secondary endpoints were surgical site infections, infectious morbidity rate defined as surgical site infections plus pulmonary infections plus urinary infections, anastomotic leakage, overall morbidity rate, major morbidity rate, reoperation and mortality rates. The results of multiple logistic regression analyses were presented as odds ratios (OR) and 95 per cent c.i. RESULTS: A total of 6157 patients were analysed to produce two well-balanced groups of 1802 patients: group (A), no abdominal drain(s) and group (B), abdominal drain(s). Group A versus group B showed a significantly lower risk of postoperative duration of stay >6 days (OR 0.60; 95 per cent c.i. 0.51-0.70; P < 0.001). A mean postoperative duration of stay difference of 0.86 days was detected between groups. No difference was recorded between the two groups for all the other endpoints. CONCLUSION: This study confirms that placement of abdominal drain(s) after elective colorectal surgery is associated with a non-clinically significant longer (0.86 days) postoperative duration of stay but has no impact on any other secondary outcomes, confirming that abdominal drains should not be used routinely in colorectal surgery.

Thermo-optic epsilon-near-zero effects.

Nonlinear epsilon-near-zero (ENZ) nanodevices featuring vanishing permittivity and CMOS-compatibility are attractive solutions for large-scale-integrated systems-on-chips. Such confined systems with unavoidable heat generation impose critical challenges for semiconductor-based ENZ performances. While their optical properties are temperature-sensitive, there is no systematic analysis on such crucial dependence. Here, we experimentally report the linear and nonlinear thermo-optic ENZ effects in indium tin oxide. We characterize its temperature-dependent optical properties with ENZ frequencies covering the telecommunication O-band, C-band, and 2-µm-band. Depending on the ENZ frequency, it exhibits an unprecedented 70-93-THz-broadband 660-955% enhancement over the conventional thermo-optic effect. The ENZ-induced fast-varying large group velocity dispersion up to 0.03-0.18 fs2nm-1 and its temperature dependence are also observed for the first time. Remarkably, the thermo-optic nonlinearity demonstrates a 1113-2866% enhancement, on par with its reported ENZ-enhanced Kerr nonlinearity. Our work provides references for packaged ENZ-enabled photonic integrated circuit designs, as well as a new platform for nonlinear photonic applications and emulations.

A chip-scale second-harmonic source via self-injection-locked all-optical poling.

Second-harmonic generation allows for coherently bridging distant regions of the optical spectrum, with applications ranging from laser technology to self-referencing of frequency combs. However, accessing the nonlinear response of a medium typically requires high-power bulk sources, specific nonlinear crystals, and complex optical setups, hindering the path toward large-scale integration. Here we address all of these issues by engineering a chip-scale second-harmonic (SH) source based on the frequency doubling of a semiconductor laser self-injection-locked to a silicon nitride microresonator. The injection-locking mechanism, combined with a high-Q microresonator, results in an ultra-narrow intrinsic linewidth at the fundamental harmonic frequency as small as 41 Hz. Owing to the extreme resonant field enhancement, quasi-phase-matched second-order nonlinearity is photoinduced through the coherent photogalvanic effect and the high coherence is mapped on the generated SH field. We show how such optical poling technique can be engineered to provide efficient SH generation across the whole C and L telecom bands, in a reconfigurable fashion, overcoming the need for poling electrodes. Our device operates with milliwatt-level pumping and outputs SH power exceeding 2 mW, for an efficiency as high as 280%/W under electrical driving. Our findings suggest that standalone, highly-coherent, and efficient SH sources can be integrated in current silicon nitride photonics, unlocking the potential of χ(2) processes in the next generation of integrated photonic devices.

Single SiGe quantum dot emission deterministically enhanced in a high-Q photonic crystal resonator.

We report the resonantly enhanced radiative emission from a single SiGe quantum dot (QD), which is deterministically embedded into a bichromatic photonic crystal resonator (PhCR) at the position of its largest modal electric field by a scalable method. By optimizing our molecular beam epitaxy (MBE) growth technique, we were able to reduce the amount of Ge within the whole resonator to obtain an absolute minimum of exactly one QD, accurately positioned by lithographic methods relative to the PhCR, and an otherwise flat, a few monolayer thin, Ge wetting layer (WL). With this method, record quality (Q) factors for QD-loaded PhCRs up to Q ∼ 105 are achieved. A comparison with control PhCRs on samples containing a WL but no QDs is presented, as well as a detailed analysis of the dependence of the resonator-coupled emission on temperature, excitation intensity, and emission decay after pulsed excitation. Our findings undoubtedly confirm a single QD in the center of the resonator as a potentially novel photon source in the telecom spectral range.

A silicon source of frequency-bin entangled photons: publisher's note.

This publisher's note contains corrections to Opt. Lett.47, 6201 (2022)10.1364/OL.471241.

Programmable frequency-bin quantum states in a nano-engineered silicon device.

Photonic qubits should be controllable on-chip and noise-tolerant when transmitted over optical networks for practical applications. Furthermore, qubit sources should be programmable and have high brightness to be useful for quantum algorithms and grant resilience to losses. However, widespread encoding schemes only combine at most two of these properties. Here, we overcome this hurdle by demonstrating a programmable silicon nano-photonic chip generating frequency-bin entangled photons, an encoding scheme compatible with long-range transmission over optical links. The emitted quantum states can be manipulated using existing telecommunication components, including active devices that can be integrated in silicon photonics. As a demonstration, we show our chip can be programmed to generate the four computational basis states, and the four maximally-entangled Bell states, of a two-qubits system. Our device combines all the key properties of on-chip state reconfigurability and dense integration, while ensuring high brightness, fidelity, and purity.

The Alternative TrkAIII Splice Variant, a Targetable Oncogenic Participant in Human Cutaneous Malignant Melanoma.

Post-therapeutic relapse, poor survival rates and increasing incidence justify the search for novel therapeutic targets and strategies in cutaneous malignant melanoma (CMM). Within this context, a potential oncogenic role for TrkA in CMM is suggested by reports of NTRK1 amplification, enhanced TrkA expression and intracellular TrkA activation associated with poor prognosis. TrkA, however, exhibits tumour-suppressing properties in melanoma cell lines and has recently been reported not to be associated with CMM progression. To better understand these contradictions, we present the first analysis of potential oncogenic alternative TrkA mRNA splicing, associated with TrkA immunoreactivity, in CMMs, and compare the behaviour of fully spliced TrkA and the alternative TrkAIII splice variant in BRAF(V600E)-mutated A375 melanoma cells. Alternative TrkA splicing in CMMs was associated with unfolded protein response (UPR) activation. Of the several alternative TrkA mRNA splice variants detected, TrkAIII was the only variant with an open reading frame and, therefore, oncogenic potential. TrkAIII expression was more frequent in metastatic CMMs, predominated over fully spliced TrkA mRNA expression in ≈50% and was invariably linked to intracellular phosphorylated TrkA immunoreactivity. Phosphorylated TrkA species resembling TrkAIII were also detected in metastatic CMM extracts. In A375 cells, reductive stress induced UPR activation and promoted TrkAIII expression and, in transient transfectants, promoted TrkAIII and Akt phosphorylation, enhancing resistance to reductive stress-induced death, which was prevented by lestaurtinib and entrectinib. In contrast, fully spliced TrkA was dysfunctional in A375 cells. The data identify fully spliced TrkA dysfunction as a novel mechanism for reducing melanoma suppression, support a causal relationship between reductive stress, UPR activation, alternative TrkAIII splicing and TrkAIII activation and characterise a targetable oncogenic pro-survival role for TrkAIII in CMM.

Bright and dark Talbot pulse trains on a chip.

Temporal Talbot effect, the intriguing phenomenon of the self-imaging of optical pulse trains, is extensively investigated using macroscopic components. However, the ability to manipulate pulse trains, either bright or dark, through the Talbot effect on integrated photonic chips to replace bulky instruments has rarely been reported. Here, we design and experimentally demonstrate a proof-of-principle integrated silicon nitride device capable of imprinting the Talbot phase relation onto in-phase optical combs and generating the two-fold self-images at the output. We show that the GHz-repetition-rate bright and dark pulse trains can be doubled without affecting their spectra as a key feature of the temporal Talbot effect. The designed chip can be electrically tuned to switch between pass-through and repetition-rate-multiplication outputs and is compatible with other related frequencies. The results of this work lay the foundations for the large-scale system-on-chip photonic integration of Talbot-based pulse multipliers, enabling the on-chip flexible up-scaling of pulse trains' repetition rate without altering their amplitude spectra.

Single-photon nonlinearities and blockade from a strongly driven photonic molecule.

Achieving the regime of single-photon nonlinearities in photonic devices by just exploiting the intrinsic high-order susceptibilities of conventional materials would open the door to practical semiconductor-based quantum photonic technologies. Here we show that this regime can be achieved in a triply resonant integrated photonic device made of two coupled ring resonators, in a material platform displaying an intrinsic third-order nonlinearity. By strongly driving one of the three resonances of the system, a weak coherent probe at one of the others results in a strongly suppressed two-photon probability at the output, evidenced by an antibunched second-order correlation function at zero-time delay under continuous wave driving.

Surgical site infections in patients undergoing breast oncological surgery during the lockdown: An unexpected lesson from the COVID-19 pandemic.

Background: The present study aims to evaluate how the measures to contain the SARS-CoV-2 spreading affected the surgical site infections (SSIs) rate in patients who underwent nondeferrable breast cancer surgery (BCS). Methods: This study is a retrospective analysis of prospectively collected data from a consecutive series of patients underwent nondeferrable BCS in a regional Italian Covid-free hub during two different period: March to April 2020 (pandemic cohort [PC]) and March till April 2019 (control cohort [CC]). SSIs were defined according to the criteria established by the Center for disease control and prevention (CDC) and additional treatment, serous discharge, erythema, purulent exudate, separation of deep tissues, isolation of bacteria, and stay (ASEPSIS) scoring systems. Results: One hundred ninety-nine patients were included in the present study: 100 and 99 patients who underwent nondeferrable BCS from March to April 2020 (PC) and from March to April 2019 (CC), respectively. The overall SSIs rate in this series was 9.1% according to CDC criteria and 6.5% according to ASEPSIS criteria. The SSIs incidence decreased during the pandemic period. Moreover, the SSIs rate according to ASEPSIS criteria was statistically lower in the PC than in the CC. We observed significant evidence of higher SSIs, both in terms of CDC and ASEPSIS score, in patients having undergone breast reconstruction compared with patients not undergoing immediate reconstruction. Conclusions: The restrictive measures issued during the lockdown period seemed to lower the SSIs rates in patients undergoing nondeferrable BCS.

Colostomy Reversal following Hartmann's Procedure: The Importance of Timing in Short- and Long-Term Complications: A Retrospective Multicentric Study.

The restoration of bowel continuity following Hartmann's Procedure (HP) has been reported hitherto with high morbidity and mortality rates. No clear guidelines exist about timing in Hartmann's Reversal (HR), the literature data being conflicting. We have sought to investigate the effect of the interval time between HP and HR in short- and long-term HR outcomes through a retrospective study based on consecutive patients undergoing HR between 2009 and 2017 in two regional hospitals in Italy. Demographic characteristics, comorbidities, intra- and post-operative data, as well as early complications, were recorded. Long-term data were collected on the surgical site occurrences of Incisional Ventral Hernia (IVH). One hundred and five patients were recruited for the study. Late HR, female gender, and long operating time were related to the highest incidence of peri-operative complications. Patients who developed IVH had undergone HR at significantly shorter times and had a higher Body Mass Index (BMI). The timing of HR seems to be an important variable linked to the onset of early and late post-operative complications. The patients submitted to early HR show a significantly lower complication rate but, at the same time, a higher rate of IVH incidence after restorative surgery. These data, in our opinion, reflect the need for planning, where possible, an early restoration of bowel continuity after HP.

Circulating tumour cell gene expression and chemosensitivity analyses: predictive accuracy for response to multidisciplinary treatment of patients with unresectable refractory recurrent rectal cancer or unresectable refractory colorectal cancer liver metastases.

BACKGROUND: Patients with unresectable recurrent rectal cancer (RRC) or colorectal cancer (CRC) with liver metastases, refractory to at least two lines of traditional systemic therapy, may receive third line intraarterial chemotherapy (IC) and targeted therapy (TT) using drugs selected by chemosensitivity and tumor gene expression analyses of liquid biopsy-derived circulating tumor cells (CTCs). METHODS: In this retrospective study, 36 patients with refractory unresectable RRC or refractory unresectable CRC liver metastases were submitted for IC and TT with agents selected by precision oncotherapy chemosensitivity assays performed on liquid biopsy-derived CTCs, transiently cultured in vitro, and by tumor gene expression in the same CTC population, as a ratio to tumor gene expression in peripheral mononuclear blood cells (PMBCs) from the same individual. The endpoint was to evaluate the predictive accuracy of a specific liquid biopsy precision oncotherapy CTC purification and in vitro culture methodology for a positive RECIST 1.1 response to the therapy selected. RESULTS: Our analyses resulted in evaluations of 94.12% (95% CI 0.71-0.99) for sensitivity, 5.26% (95% CI 0.01-0.26) for specificity, a predictive value of 47.06% (95% CI 0.29-0.65) for a positive response, a predictive value of 50% (95% CI 0.01-0.98) for a negative response, with an overall calculated predictive accuracy of 47.22% (95% CI 0.30-0.64). CONCLUSIONS: This is the first reported estimation of predictive accuracy derived from combining chemosensitivity and tumor gene expression analyses on liquid biopsy-derived CTCs, transiently cultured in vitro which, despite limitations, represents a baseline and benchmark which we envisage will be improve upon by methodological and technological advances and future clinical trials.

Reverse strategy to locally advanced breast implant-associated anaplastic large cell lymphoma: A case report.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare T-cell lymphoma associated with textured breast implants. The most common presentation is a periprosthetic seroma that occurs at least 1 year after an aesthetic or reconstructive implantation, and in these cases, the surgical treatment seems to be successful. More rarely, BIA-ALCL presents with locally advanced mass-formed disease and a related regional lymph node involvement. In all these cases with worse prognosis, a multidisciplinary approach is required, including adjuvant chemotherapy, radiation therapy, and surgery. We present a clinical case of a 49-year-old woman who developed on the left side of the breast a mass-formed stage 3 BIA-ALCL 15 years after a bilateral breast augmentation with textured silicone implant. Our multidisciplinary team (MDT) scheduled the patient for a "reverse-strategy" sequential approach consisting of induction chemotherapy, hematopoietic stem cell mobilization, and harvest followed by autologous stem cell transplant (ASCT). After 100 days from the stem cell transplant, the patient showed a complete pathologic response and was a candidate for radical surgery. She underwent removal of both implants with total en bloc capsulectomy. On the left site, the periprosthetic mass was also en bloc removed. We did not perform any axillary dissection. Our surgical and hemato-oncological teams followed the patient every 3 months, and no local or systemic recurrences were observed 24 months after surgery. This case report has demonstrated the effectiveness of neoadjuvant chemotherapy as part of a "reverse strategy" in selected cases of advanced-stage BIA-ALCL in which it was not possible to perform an immediate radical surgery. Furthermore, in our case, the de-escalation strategy adopted permitted a less demolitic surgery with good functional and aesthetic results.

Silicon source of frequency-bin entangled photons.

We demonstrate an integrated source of frequency-entangled photon pairs on a silicon photonics chip. The emitter has a coincidence-to-accidental ratio exceeding 103. We prove entanglement by showing two-photon frequency interference with a visibility of 94.6% ± 1.1%. This result opens the possibility of on-chip integration of frequency-bin sources with modulators and the other active and passive devices available in the silicon photonics platform.

Thermo-optically induced transparency on a photonic chip.

Controlling the optical response of a medium through suitably tuned coherent electromagnetic fields is highly relevant in a number of potential applications, from all-optical modulators to optical storage devices. In particular, electromagnetically induced transparency (EIT) is an established phenomenon in which destructive quantum interference creates a transparency window over a narrow spectral range around an absorption line, which, in turn, allows to slow and ultimately stop light due to the anomalous refractive index dispersion. Here we report on the observation of a new form of both induced transparency and amplification of a weak probe beam in a strongly driven silicon photonic crystal resonator at room temperature. The effect is based on the oscillating temperature field induced in a nonlinear optical cavity, and it reproduces many of the key features of EIT while being independent of either atomic or mechanical resonances. Such thermo-optically induced transparency will allow a versatile implementation of EIT-analogs in an integrated photonic platform, at almost arbitrary wavelength of interest, room temperature and in a practical, low cost, and scalable system.