Acute idiopathic mesenteroaxial gastric volvulus managed laparoscopically.

Gastric volvulus is an uncommon cause of upper gastrointestinal obstruction that occurs when the stomach twists along its vertical (organoaxial) or horizontal (mesenteroaxial) axis. Its rarity combined with its non-specific presentation makes gastric volvulus a diagnostic challenge, especially when the volvulus occurs without underlying structural abnormality such as hiatal hernia. The organoaxial type comprises most cases of this rare diagnosis. Few cases of mesenteroaxial volvulus have been reported in children and even fewer in adults. Here, we present a rare case of acute, idiopathic mesenteroaxial volvulus in a patient in his 70s, that was successfully managed laparoscopically.

Hydrogen-Bond-Driven Peptide Nanotube Formation: A DFT Study.

DFT calculations were carried out to examine geometries and binding energies of H-bond-driven peptide nanotubes. A bolaamphiphile molecule, consisting of two N-α amido glycylglycine head groups linked by either one CH2 group or seven CH2 groups, is used as a building block for nanotube self-assembly. In addition to hydrogen bonds between adjacent carboxy or amide groups, nanotube formation is also driven by weak C-H· · ·O hydrogen bonds between a methylene group and the carboxy OH group, and between a methylene group and an amide O=C group. The intratubular O-H· · ·O=C hydrogen bonds account for approximately a third of the binding energies. Binding energies calculated with the wB97XD/DGDZVP method show that the hydrocarbon chains play a stabilizing role in nanotube self-assembly. The shortest nanotube has the length of a single monomer and a diameter than increases with the number of monomers. Lengthening of the tubular structure occurs through intertubular O-H· · ·O=C hydrogen bonds. The average intertubular O-H· · ·O=C hydrogen bond binding energy is estimated to change with the size of the nanotubes, decreasing slightly towards some plateau value near 15 kcal/mol according to the wB97XD/DGDZVP method.

Bracelet-like Complexes of Lithium Fluoride with Aromatic Tetraamides, and Their Potential for LiF-Mediated Self-Assembly: A DFT Study.

Geometries and binding energies of complexes between a LiF molecule and a model aromatic tetraamide are obtained using various DFT methods. The tetraamide consists of a benzene ring and four amides positioned so that the LiF molecule can bind via Li⋯O=C or N-H⋯F interactions. The complex with both interactions is the most stable one, followed by the complex with only N-H⋯F interactions. Doubling the size of the former resulted in a complex with a LiF dimer sandwiched between the model tetraamides. In turn, doubling the size of the latter resulted in a more stable tetramer with bracelet-like geometry having the two LiF molecules also sandwiched but far apart from each other. Additionally, all methods show that the energy barrier to transition to the more stable tetramer is small. The self-assembly of the bracelet-like complex mediated by the interactions of adjacent LiF molecules is demonstrated by all computational methods employed.

Cholecystocolonic fistula: two different presentations of this rare complication of gallstones.

Cholecystocolonic fistulas (CCF) are a rare but significant complication of biliary disease, frequently presenting as gallstone ileus. Although there is no one agreed-upon procedure, enterolithotomy appears to be the initial treatment of choice; with a subsequent cholecystectomy performed ~4-8 weeks later. Alternatively, a patient may undergo a single-stage procedure, at which time an enterolithotomy, cholecystectomy and fistula closure are performed. Herein, we describe two patients with chronic cholecystitis and subsequent development of CCF with differing presentations. We report the clinical, radiographic and intraoperative findings and discuss the surgical treatment options for each patient, respectively.

Enhancing Effects of the Cyano Group on the C-X∙∙∙N Hydrogen or Halogen Bond in Complexes of X-Cyanomethanes with Trimethyl Amine: CH3-n(CN)nX∙∙∙NMe3, (n = 0-3; X = H, Cl, Br, I).

In this paper, density functional theory and wave function theory calculations are carried out to investigate the strength and nature of the intermolecular C-X∙∙∙N bond interaction as a function of the number of cyano groups, CN, in the X-bond donor while maintaining the X-bond acceptor as fixed. Specifically, complexes of X-cyanomethanes with trimethyl amine CH3-n(CN)nX∙∙∙NMe3 (n = 0-3; X = H, Cl, Br, I) are used as model systems. Geometrical parameters and vibrational C-X-stretching frequencies as well as interaction energies are used as relevant indicators to gauge hydrogen or halogen bond strength in the complexes. Additional characteristics of interactions that link these complexes, i.e., hydrogen or halogen bonds, are calculated with the use of the following theoretical tools: the atoms in molecules (AIM) approach, the natural bond orbital (NBO) method, and energy decomposition analysis (EDA). The results show that, for the specified X-center, the strength of C-X∙∙∙N interaction increases significantly and in a non-additive fashion with the number of CN groups. Moreover, the nature (noncovalent or partly covalent) of the interactions is revealed via the AIM approach.

Sandwich, Triple-Decker and Other Sandwich-like Complexes of Cyclopentadienyl Anions with Lithium or Sodium Cations.

Density functional theory, DFT, calculations were carried out on complexes containing cyclopentadienyl anions and lithium or sodium cations; half-sandwich, sandwich and sandwich-like complexes (among them triple-decker ones) are analyzed. Searches performed through the Cambridge Structural Database revealed that crystal structures containing these motifs exist, mostly structures with sodium cations. The DFT calculations performed here include geometry optimization and frequency calculations of the complexes at the ωB97XD/aug-cc-pVTZ level, followed by the partitioning of the energy of interaction via the Energy Decomposition Analysis scheme, EDA, at the BP86-D3/TZ2P level. Additional calculations and analyses were performed using both the Quantum Theory of Atoms in Molecules, QTAIM, and the Natural Bond Orbital analyses, NBO. The results of this work show that the electrostatic interaction energy is the most important attractive contribution to the total interaction energy of each of the complex systems analyzed here, and that complexation itself leads to minor electron charge shifts.

Robotic Intracorporeal Rectus Aponeuroplasty: Early Experience of a New Surgical Technique for Ventral Hernia Repair.

Introduction: The laparoscopic intracorporeal rectus aponeuroplasty (LIRA) was developed as an alternative for minimally invasive ventral hernia repair. This technique allows the closure of the defect and restoration of the midline without tension by plication of both aponeurosis of the abdominal rectus muscles combined with a minimally invasive intraperitoneal underlay mesh repair. The objective of this study is to report our early experience with the Robotic-LIRA (R-LIRA) technique and its safety and short-term efficacy. Methods: We performed a retrospective analysis of patients undergoing R-LIRA repair for ventral hernias from March 2019 to April 2022. Results: Eight patients underwent R-LIRA from March 2019 to April 2022. Median age was 47 years (interquartile range [IQR] 34.5-62.8). Median body mass index was 34.2 kg/m2 (IQR 29.9-35.2). Four patients (50%) had a primary ventral hernia being one M2, two M3, and one M2/M3. There were three incisional hernias, being one recurrent, 6 patients (75%) had associated diastasis of the rectus muscle and 1 patient presented pure diastasis. The median hernia width was 4 cm (IQR 2-6), and the median defect area was 16 cm2 (IQR 4-42). The median mesh area was 290 cm2 (IQR 211.2-300). In all cases, a barbed suture was also used for mesh fixation, and tackers were added in 4 cases. The median operative time was 172 minutes (IQR 139.8-293.3). The median length of stay was 0.5 days (IQR 0-1.8), and the median follow-up was 20 days (IQR 16-46). Conclusion: The R-LIRA has been shown to be safe and feasible for ventral and incisional hernia repairs with or without Diastasis of the Rectus Abdominis Muscle in the short term.

A Microcosm of Disparities in Breast Cancer: Comparison Between a Private Hospital and a Safety-Net County Hospital Within Los Angeles County.

BACKGROUND: Breast cancer survival is improving due to early detection and treatment advances. However, racial/ethnic differences in tumor biology, stage, and mortality remain. The objective of this study was to analyze presumed disparities at a local level. METHODS: Breast cancer patients at a county hospital and private hospital from 2010 to 2012 were retrospectively reviewed. Demographic, clinical, pathologic, and surgical data were collected. Comparisons were made between hospital cohorts and between racial/ethnic groups from both hospitals combined. RESULTS: 754 patients were included (322 from county hospital and 432 from private hospital). All patients were female. The median age was 54 years at county hospital and 60 years at private hospital (P < .0001). Racial/ethnic minorities comprised 85% of county hospital patients vs. 12% of private hospital patients (P < .0001). County hospital patients had a higher grade, clinical/pathologic stage, HER2-positive rate, and mastectomy rate. Compared to other racial/ethnic groups, non-Hispanic white women were more likely to have lower grade and ER-positive tumors. Hispanic/Latina women were younger and were more likely to have HER2-positive tumors. Both Hispanic/Latina and non-Hispanic black women presented at higher clinical stages and were more likely to undergo neoadjuvant chemotherapy and mastectomy. DISCUSSION: At county hospital compared to private hospital, the proportion of racial/ethnic minorities was higher, and patients presented at younger ages with more aggressive tumors and more advanced disease. The racial/ethnic disparities that were identified locally are largely consistent with those identified in national database studies. These marked differences at hospitals within a diverse city highlight the need for further research into the disparities.

Robotic Inguinal Hernia Repair After Prostatectomy: How to Navigate Safely.

INTRODUCTION: In recent decades, minimally invasive approaches have found their place in treating a specific subset of patients with inguinal hernias, predominantly those with recurrent or bilateral disease. Classically, prior history of urologic pelvic operations, such as prostatectomy, has been listed as relative contraindication for minimally invasive inguinal hernia repair. As the adoption of the robotics platform continues to grow, we aim to outline a feasible robotic-assisted inguinal hernia repair technique in patients with previous prostatectomies. We report the outcomes of 15 patients who underwent repair at 2 institutions. METHODS: This is a retrospective case series of 15 patients who underwent robotic transabdominal preperitoneal approach repair of their inguinal hernias after prostatectomy. Demographics, intraoperative variables, and outcomes of our cases are described. RESULTS: Fifteen patients were included in our cohort. All patients had a history of prostatectomy (7 open, 2 laparoscopic, and 6 robotic) due to prostate cancer. Median age was 70 years old (range: 60 to 89 y), with a median body mass index of 26.3 kg/m2 (range: 20.5 to 37.4 kg/m2). Hernia defects were bilateral in 6 patients and unilateral in the remaining 9 (right; 6, left; 3). The shortest interval between prostatectomy and subsequent hernia repair was 4 months (range: 4 to 216 mo). The median operative time was 139 min (range: 91 to 281 min). All defects were repaired using a polypropylene mesh except in 1 case, where a coated monofilament polyester mesh was used after having a large peritoneal defect to close, preventing future adhesions to the bowel. Mesh sizes used were large (16×11 cm), extra-large (17×12 cm) for anatomic mesh, and 20×15 cm for the monofilament polyester mesh. The mesh was fixed in 14 of 15 cases. Fixation was accomplished with absorbable suture (n=13), barbed suture (n=1), and fibrin sealant (n=1). Peritoneal closure was always performed using a continuous running v-loc suture. There were no documented major intraoperative complications, no 30-day readmission, or recurrences recorded within the follow-up period. Postoperatively, only 2 seromas and 1 hematoma were documented during the follow-up period. CONCLUSIONS: Robotic inguinal hernia repairs in patients with previous prostatectomy is safe and feasible in most patients. Larger patient series are needed to confirm these findings.

Synthesis, LC-MS/MS analysis, and biological evaluation of two vaccine candidates against ticks based on the antigenic P0 peptide from R. sanguineus linked to the p64K carrier protein from Neisseria meningitidis.

A peptide from the P0 acidic ribosomal protein (pP0) of ticks conjugated to keyhole limpet hemocyanin from Megathura crenulata has shown to be effective against different tick species when used in host vaccination. Turning this peptide into a commercial anti-tick vaccine will depend on finding the appropriate, technically and economically feasible way to present it to the host immune system. Two conjugates (p64K-Cys1pP0 and p64K-ßAla1pP0) were synthesized using the p64K carrier protein from Neisseria meningitidis produced in Escherichia coli, the same cross-linking reagent, and two analogues of pP0. The SDS-PAGE analysis of p64K-Cys1pP0 showed a heterogeneous conjugate compared to p64K-ßAla1pP0 that was detected as a protein band at 91kDa. The pP0/p64K ratio determined by MALDI-MS for p64K-Cys1pP0 ranged from 1 to 8, being 3-5 the predominant ratio, while in the case of p64K-ßAla1pP0 this ratio was 5-7. Cys1pP0 was partially linked to 35 out of 39 Lys residues and the N-terminal end, while ßAla1pP0 was mostly linked to the six free cysteine residues, to the N-terminal end, and, in a lesser extent, to Lys residues. The assignment of the conjugation sites and side reactions were based on the identification of type 2 peptides. Rabbit immunizations showed the best anti-pP0 titers and the highest efficacy against Rhipicephalus sanguineus ticks when the p64K-Cys1pP0 was used as vaccine antigen. The presence of high molecular mass aggregates observed in the SDS-PAGE analysis of p64K-Cys1pP0 could be responsible for a better immune response against pP0 and consequently for its better efficacy as an anti-tick vaccine. Graphical abstract.

Unusual presentation of rectal squamous cell carcinoma perforation-case report and literature review.

This is an unusual case of an obstructive rectal squamous cell carcinoma (SCC), causing perforation and a pelvic abscess, requiring source control and diverting colostomy. A 50-year-old female with chronic constipation presented with worsening right buttock pain for 1 month. On exam, the patient reported right hip tenderness. A computer tomography (CT) revealed rectal wall thickening with a presacral abscess. Due to the concern of rectal perforation with abscess she was taken to the operating room for proctoscopy with biopsy, colostomy diversion and drainage of the abscess over the right buttock. Pathology reported invasive rectal SCC. Rectal SCC presents similarly to rectal adenocarcinoma but its diagnosis must include special markers for cytokeratins. The treatment approach is controversial but adequately treated offers better survival than rectal ADC. Rectal SCC is rare and treated with chemoradiation however it must also be tailored to the variable acute presentations.

Duodenal perforation in the pediatric population: two rare cases at a small community hospital.

Duodenal ulcer perforation is very uncommon in the pediatric population; hence, it is usually not considered in the differential diagnosis of acute abdomen in this age group. In our small community hospital, we had two rare cases of perforated peptic ulcer in the pediatric population within a short span of time. A 14-year-old male and a 13-year-old female child presented to the emergency room with acute abdominal pain. No other symptoms were reported and neither had any history of peptic ulcer disease. Abdominal CT showed pneumoperitoneum consistent with perforated hollow viscus. Subsequent exploratory laparotomy indicated perforated duodenal ulcer in both children. These cases illustrate that perforated peptic ulcers should be considered in children presenting with acute abdomen.

Dedifferentiated liposarcoma of the scrotum. Case report and literature review.

Malignant paratesticular and spermatic cord tumors are rare and often misdiagnosed preoperatively due to clinical presentations similar to other benign scrotal mass etiologies. Only a few cases regarding giant, paratesticular liposarcomas (>10 cm) have been reported. We report a unique case of an aggressive giant dedifferentiated liposarcoma of the scrotum with osteosarcoma features in a 70-year-old patient who initially presented with indolent scrotal swelling. A CT scan showed a large, complex, solid and cystic mass (12.0 x 15.5 x 19.0 cm) in the right scrotum. With a concern of a complex hydrocele, the patient was taken to the operating room for a scrotal approach to excise the hydrocele, but the spermatic cord was not traced to any discernible testicle as the entire mass was indurated and multilocular, and was excised. Pathology revealed a dedifferentiated liposarcoma, with MDM2 amplification. The patient's course was complicated due to metastatic disease.

Pneumoperitoneum and Pneumatosis cystoides intestinalis, a dangerous mixture. A case report.

BACKGROUND: Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by gas infiltration into the intestine wall. When gas is seen in the intestinal wall, it is usually a sign of bowel wall infarction and a surgical emergency; therefore, an adequate differentiation of benign and urgent conditions of pneumatosis intestinalis is necessary to prevent misdiagnosis and inadequate therapies. CASE PRESENTATION: We present the case of a 79-year-old male with past medical history of Alzheimer's, cholecystectomy, and umbilical hernia. PCI was identified, and conservative therapy was started. Since the patient's pain persisted, a complication was suspected, and surgery was decided. After successful treatment, the patient completely recovered. CONCLUSION: There are many benign and life-threatening causes of pneumatosis intestinalis, the imaging appearance of both may look very similar. Therefore, clinical history, physical examination, and laboratory test results are the best indicators of whether it is due to a benign or life-threatening cause. PCI must be managed with a multidisciplinary team of clinicians, radiologists, and surgeons to achieve better results for our patients.

Spatio-temporal immunolocalization of extensin protein and hemicellulose polysaccharides during olive fruit abscission.

MAIN CONCLUSION: Immunocytochemical and molecular analyses reveal that the disassembly of the cell wall may be mediated by changes in the level and subcellular location of extensin protein and hemicelluloses during olive-fruit abscission. Although cell-wall modification is believed to underlie the changes in organ abscission, information concerning the changes in cell-wall proteins and hemicellulose polysaccharides is still limited. The aim of this work was to analyze the spatio-temporal patterns of the distribution of different extensin proteins and hemicelluloses in the abscission zone (AZ) during natural ripe-fruit abscission in olive (Olea europaea L.). In this study, we employed immunogold labeling in the ripe-fruit AZ during olive AZ cell separation, using an expanded set of monoclonal antibodies that recognize different types of hemicelluloses (LM11, LM15, and LM21), callose (anti-(1,3)-ß-D-glucan) and extensin (JIM19) epitopes, and transmission electron microscopy imaging. Our data demonstrate that AZ cell separation was accompanied by a loss of the JIM19 extensin epitopes and a reduction in the detection of the LM15 xyloglucan epitopes in AZ cell walls, whereas AZ cells were found to be enriched with respect to the xylan and callose levels of the cell wall during olive ripe-fruit abscission. By contrast, AZ cell-wall polysaccharide remodeling did not involve mannans. Moreover, in ripe-fruit AZ, quantitative RT-PCR analysis revealed that OeEXT1, OeEXT2, OeXTH9, and OeXTH13 genes were downregulated during abscission, whereas the expression of OeXTH1, OeXTH5, and OeXTH14 genes increased during abscission. Taken together, the results indicate that AZ cell-wall dynamics during olive ripe-fruit abscission involves extensin protein and hemicellulose modifications, as well as related expressed genes. This is the first study available demonstrating temporal degradation of extensin protein and hemicelluloses in the AZ at the subcellular level.

Splenic abscess after arterial embolization: a rare cause of acute abdomen.

Splenic abscess is a rare disease and a diagnostic challenge for the medical team. Attributable to its high mortality, prompt diagnosis and treatment are essential. A high degree of clinical awareness is required in conjunction with aggressive treatment, as misleading symptoms may delay treatment and worsen the patient's prognosis. The management of splenic abscess is based on medical therapy, antibiotics and splenectomy or percutaneous drainage. We present the case of a 58-year-old patient presented with a splenic abscess after arterial embolization. He underwent surgery and completely recovered.

Cell Wall Composition and Ultrastructural Immunolocalization of Pectin and Arabinogalactan Protein during Olea europaea L. Fruit Abscission.

Cell wall modification is integral to many plant developmental processes where cells need to separate, such as abscission. However, changes in cell wall composition during natural fruit abscission are poorly understood. In olive (Olea europaea L.), some cultivars such as 'Picual' undergo massive natural fruit abscission after fruit ripening. This study investigates the differences in cell wall polysaccharide composition and the localization of pectins and arabinogalactan protein (AGP) in the abscission zone (AZ) during cell separation to understand fruit abscission control in 'Picual' olive. To this end, immunogold labeling employing a suite of monoclonal antibodies to cell wall components (JIM13, LM5, LM6, LM19 and LM20) was investigated in olive fruit AZ. Cell wall polysaccharide extraction revealed that the AZ cell separation is related to the de-esterification and degradation of pectic polysaccharides. Moreover, ultrastructural localization showed that both esterified and unesterified homogalacturonans (HGs) localize mainly in the AZ cell walls, including the middle lamella and tricellular junction zones. Our results indicate that unesterified HGs are likely to contribute to cell separation in the olive fruit AZ. Similarly, immunogold labeling demonstrated a decrease in both galactose-rich and arabinose-rich pectins in AZ cell walls during ripe fruit abscission. In addition, AGPs were localized in the cell wall, plasma membrane and cytoplasm of AZ cells with lower levels of AGPs during ripe fruit abscission. This detailed temporal profile of the cell wall polysaccharide composition, and the pectins and AGP immunolocalization in the olive fruit AZ, offers new insights into cell wall remodeling during ripe fruit abscission.

Giant ovarian cystadenocarcinoma in an adult patient, a rare finding in modern times.

Ovarian cancer (OC) is one of the most commonly diagnosed cancers among women. Regretfully due to its a broad spectrum of clinical behavior and challenging diagnosis most cases are diagnosed at a late stage. On rare occasions, these tumors can grow to massive sizes if left untreated, worsening the prognosis of the patient. Thanks to the advancement of medicine and diagnostic techniques, these rare cases are less frequent. Timely detection and surgery could avoid all these potentially troublesome scenarios. We report the case of a 64-year-old female with a giant 13 kg high-grade papillary serous ovarian cystadenocarcinoma, the tumor grew during a four year period and was adequately treated with surgery and is under close follow up with the oncologist. To our knowledge, this is the first case of a giant ovarian cystadenocarcinoma ever reported in Ecuador.

Cyclic networks of halogen-bonding interactions in molecular self-assemblies: a theoretical N-X...N versus C-X...N investigation.

The geometries and energetics of molecular self-assembly structures that contain a sequential network of cyclic halogen-bonding interactions are investigated theoretically. The strength of the halogen-bonding interactions is assessed by examining binding energies, electron charge transfer (NBO analysis) and electron density at halogen-bond critical points (AIM theory). Specifically, structural motifs having intramolecular N-X...N (X = Cl, Br, or I) interactions and the ability to drive molecular self-assembly via the same type of interactions are used to construct larger self-assemblies of up to three unit motifs. N-X...N halogen-bond cooperativity as a function of the self-assembly size, and the nature of the halogen atom is also examined. The cyclic network of the halogen-bonding interactions provides a suitable cavity rich in electron density (from the halogen atom lone pairs not involved in the halogen bonds) that can potentially bind an electron-deficient species such as a metal ion. This possibility is explored by examining the ability of the N-X...N network to bind Na+. Likewise, molecular self-assembly structures driven by the weaker C-X...N halogen-bonding interactions are investigated and the results compared with those of their N-X...N counterparts.

Concerted halogen bonding and orthogonal metal-halogen interactions in dimers of lithium formamidinate and halogenated formamidines: an ab initio study.

Dimers of lithium formamidinate, CH(NH)2Li, and halogenated formamidines, HN=CHNHX, (X=Cl, Br, or I) are used as model systems to investigate simultaneous N-X···N and N-Li···N interactions, in tandem with orthogonal Li···X interactions. Geometry optimizations and energy calculations for the dimers are examined with the MP2 method and the M06-2X hybrid functional and the aug-cc-pVTZ basis set (the aug-cc-pVTZ-PP basis set is used for the iodine atom). Both methods predict the formation of a planar structure of C2v symmetry, regardless of the identity of the halogen atom. In this structure, the identities of the constituent monomers are essentially lost. Accordingly, the N-X···N interactions emerge as a rather symmetric quasi-linear N···X···N, where the covalent N-X bond in the halogenated formamidine is replaced by a partly covalent N···X interaction. Formation of the C2v structure is also driven by a fairly linear N···Li···N interaction parallel to the N···X···N interaction, and a Li···X interaction orthogonal to both the N···X···N and N···Li···N interactions. The strength of the interactions increases with the size of the halogen. The robustness of the interactions suggests that the dimers studied here or suitable analogues may find diverse applications including their use as novel polymeric synthons.