Postoperative pain in transabdominal preperitoneal laparoscopic hernia repair with staple fixation versus self-fixation mesh.

Background: The mesh fixation method is one of the multiple factors associated with chronic postoperative pain in inguinal hernia surgery. The aim of this study is to evaluate postoperative pain associated with the two available fixation strategies (staple fixation versus self-fixating mesh) used in our field. Methods: We designed an observational study with retrospective cohorts to analyze postoperative pain in patients who underwent a laparoscopic transabdominal preperitoneal inguinal hernia repair with a self-fixating mesh or staple fixation, which are the two available techniques in our field. A total of 296 patients who met the inclusion criteria were included between January 2014 and October 2021. Results: The evaluated patients' median age was 66.0 (interquartile range (IQR): 20.75) years and were predominantly male (70.13 %). The proportion of participants with chronic pain was 3.20 % in the staple fixation group and 0 % in the self-fixating mesh group, with no statistically significant differences. On the other hand, recurrency in the staple fixation group was 2.28 % versus 3.90 % in the self-fixating mesh group, without statistically significant differences. Conclusions: Self-fixating meshes have a trend towards smaller proportion of chronic pain and similar proportions of recurrence; therefore, they seem to be the best fixation method between the two mechanisms that are available in our field to prevent postoperative chronic pain.

Penile necrosis due to monkeypox.

Since 2022 Monkeypox virus (MPXV) infection incidence of cases has increased. Genitourinary lesions and penile edema are one of the main causes of emergency room visits. We aim to describe a 36-year-old man with MPXV infection and newly diagnosed with HIV and low CD4+ count, who developed a rapidly extensive penile necrosis. Extensive surgical debridement was performed and necrosis compromise was confirmed in the histopathological findings. We provide novel forms of presentation of MPXV, improving data collection and awarding health workers for a correct differential diagnosis.

Antibiotic prophylaxis in flexible ureterorenoscopy with negative urine culture.

Objective: To improve susceptibility profiles of nosocomial bacteria, identifying the difference between infectious complications in patients undergoing endoscopic flexible ureterolithotomy (fURS) with negative urine culture (UC) that received extended antibiotic prophylaxis (EP) compared with standard antibiotic prophylaxis (SP). Methodology: This is a retrospective, observational, analytical cohort study, comparing infectious complications between patients undergoing fURS with negative UC who received EP versus SP. We include patients with susccessfull fURS, <20-mm stones and complete information. Results: Overall, 10.3% of patients had complications, 7.2% of patients had postoperative urinary infection, 1.8% had upper urinary tract infection (UTI) and 1.4% had urinary sepsis. Lower UTI were significantly more likely in the extended prophylaxis group with 6.8% versus 2.7% (RR = 2.8; 95% CI: 1.10-7.37, p = 0.030). The risk of upper UTI and sepsis did not show significant differences. A total of 69% patients with postoperative infection had isolated multidrug-resistant bacteria (MDRB) in the UC, with a higher risk in patients with extended prophylaxis (RR = 3.1; 95% CI: 1.33-7.59, p = 0.009). Conclusions: Patients with negative UC who underwent fURS using extended prophylaxis have two times higher risk of low UTI than patients with standard prophylaxis, without differences in the incidence of upper UTI or urinary sepsis. The risk of MDRB isolation in the postoperative UC is higher in the extended prophylaxis group, therefore we recommend the standard 60-min preoperative prophylaxis.

Síndrome de Alicia en el país de las maravillas (AIWS). Reflexión / Alice in Wonderland Syndrome (AIWS). A reflection

Abstract The Alice in Wonderland syndrome is a rare clinical neurological condition, defined by the presence of perception disorders usually interpreted by the affected patient as rare metamorphosing and depersonalization phenomena. Due to its extremely rare occurrence and its surreal and sometimes psychedelic character, the syndrome has been associated with the phenomena experienced by Alice, the character in the classic and world-famous story by Lewis Carroll.

Resumen El Síndrome de Alicia en el País de las Maravillas es una condición clínica neurológica de rara aparición, definida por la aparición de alteraciones en la percepción usualmente interpretadas por el paciente que las experimenta, como fenómenos extraños de metamorfosis y despersonalización. Por su naturaleza altamente inusual y su carácter surreal e incluso en ocasiones psicodélico, se ha relacionado al cuadro con los fenómenos experimentados por el personaje de Alicia, en la clásica y mundialmente reconocida historia de Lewis Carroll.

Spectral properties and orientation of voltage-sensitive dyes in lipid membranes.

Voltage-sensitive dyes are frequently used for probing variations in the electric potential across cell membranes. The dyes respond by changing their spectral properties: measured as shifts of wavelength of absorption or emission maxima or as changes of absorption or fluorescence intensity. Although such probes have been studied and used for decades, the mechanism behind their voltage sensitivity is still obscure. We ask whether the voltage response is due to electrochromism as a result of direct field interaction on the chromophore or to solvatochromism, which is the focus of this study, as result of changed environment or molecular alignment in the membrane. The spectral properties of three styryl dyes, di-4-ANEPPS, di-8-ANEPPS, and RH421, were investigated in solvents of varying polarity and in model membranes using spectroscopy. Using quantum mechanical calculations, the spectral dependence of monomer and dimer ANEPPS on solvent properties was modeled. Also, the kinetics of binding to lipid membranes and the binding geometry of the probe molecules were found relevant to address. The spectral properties of all three probes were found to be highly sensitive to the local environment, and the probes are oriented nearly parallel with the membrane normal. Slow binding kinetics and scattering in absorption spectra indicate, especially for di-8-ANEPPS, involvement of aggregation. On the basis of the experimental spectra and time-dependent density functional theory calculations, we find that aggregate formation may contribute to the blue-shifts seen for the dyes in decanol and when bound to membrane models. In conclusion, solvatochromic and other intermolecular interactions effects also need to be included when considering electrochromic response voltage-sensitive dyes.

Effects of tryptophan content and backbone spacing on the uptake efficiency of cell-penetrating peptides.

Cell-penetrating peptides (CPPs) are able to traverse cellular membranes and deliver macromolecular cargo. Uptake occurs through both endocytotic and nonendocytotic pathways, but the molecular requirements for efficient internalization are not fully understood. Here we investigate how the presence of tryptophans and their position within an oligoarginine influence uptake mechanism and efficiency. Flow cytometry and confocal fluorescence imaging are used to estimate uptake efficiency, intracellular distribution and toxicity in Chinese hamster ovarian cells. Further, membrane leakage and lipid membrane affinity are investigated. The peptides contain eight arginine residues and one to four tryptophans, the tryptophans positioned either at the N-terminus, in the middle, or evenly distributed along the amino acid sequence. Our data show that the intracellular distribution varies among peptides with different tryptophan content and backbone spacing. Uptake efficiency is higher for the peptides with four tryptophans in the middle, or evenly distributed along the peptide sequence, than for the peptide with four tryptophans at the N-terminus. All peptides display low cytotoxicity except for the one with four tryptophans at the N-terminus, which was moderately toxic. This finding is consistent with their inability to induce efficient leakage of dye from lipid vesicles. All peptides have comparable affinities for lipid vesicles, showing that lipid binding is not a decisive parameter for uptake. Our results indicate that tryptophan content and backbone spacing can affect both the CPP uptake efficiency and the CPP uptake mechanism. The low cytotoxicity of these peptides and the possibilities of tuning their uptake mechanism are interesting from a therapeutic point of view.

Correlation between cellular localization and binding preference to RNA, DNA, and phospholipid membrane for luminescent ruthenium(II) complexes.

Because of their unique photophysical properties, sensitively depending on environment, ruthenium dipyridophenazine (dppz) complexes are interesting as probes for cellular imaging with fluorescence microscopy. Here three complexes derivatized with alkyl ether chains of varied length, which exhibit distinctly different cellular staining patterns by confocal laser scanning microscopy, are studied regarding their binding preference for rRNA compared with calf thymus DNA (ct-DNA) and phospholipid membranes. Co-staining with commercial RNA and membrane-specific dyes shows that whereas the least lipophilic complex exclusively stains DNA inside the nucleus, the most lipophilic complex preferentially stains membrane-rich parts of the cell. Interestingly, only the intermediate lipophilic complex shows intense staining of the RNA-rich nucleoli. The intracellular localizations of the probes correlate with their binding preferences concluded from spectroscopy measurements.

Lipophilic ruthenium complexes with tuned cell membrane affinity and photoactivated uptake.

Ruthenium dipyridophenazine (dppz) complexes are virtually non-emissive in aqueous solutions but show strong luminescence in hydrophobic environments, making them interesting as molecular probes in cellular imaging. We show by luminescence spectroscopy that by substituting the dppz ligand with alkyl ether chains of increasing length the complexes can be tuned from preferential intercalation into DNA to insertion in model phospholipid membranes. Confocal laser scanning microscopy (CLSM) on methanol fixed CHO-K1 cells show an analogous distribution in the cell, where the least hydrophobic complex exclusively stains the nucleus whereas the more hydrophobic ones seem to predominantly stain membrane structures in the cytoplasm. In live cells CLSM show that initially only the more hydrophobic derivatives stain the plasma membrane. However, brief further exposure to the laser light causes permeabilization of the membrane and accumulation of extracellular ruthenium complexes in internal cellular structures, similarly to the distribution found in fixed cells.