Diverse Reactivity of Dienes with Pentaphenylborole and 1-Phenyl-2,3,4,5-Tetramethylborole Dimer.

The reactions of a monomeric borole and a dimeric borole with 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene were investigated. The monomeric borole reacted at ambient temperature whereas heat was required to crack the dimer to form the monomer and induce reactivity. 2,3-Dimethyl-1,3-butadiene reacts to give diverse products resulting from a cycloaddition process with the B-C moiety of the boroles acting as a dienophile, followed by rearrangements to furnish bicyclic species. For 1,3-cyclohexadiene, a [4+2] process is observed in which 1,3-cyclohexadiene serves as the dienophile and the boroles as the diene partner. The experimental results are corroborated with mechanistic theoretical calculations that indicate boroles can serve as either a diene or dienophile in cycloaddition reactions with dienes.

Systematic review and network meta-analysis of methods of mesh fixation during laparoscopic ventral hernia repair.

BACKGROUND: Ventral hernia repairs are common and have high recurrence rates. They are usually repaired laparoscopically with an intraperitoneal mesh, which can be fixed in various ways. The aim was to evaluate the recurrence rates for the different fixation techniques. METHODS: This systematic review included studies with human adults with a ventral hernia repaired with an intraperitoneal onlay mesh. The outcome was recurrence at least 6 months after operation. Cohort studies with 50 or more participants and all RCTs were included. PubMed, Embase and the Cochrane Library were searched on 22 September 2016. RCTs were assessed with the Cochrane risk-of-bias assessment tool and cohort studies with the Newcastle-Ottawa scale. Studies comparing fixation techniques were included in a network meta-analysis, which allowed comparison of more than two fixation techniques. RESULTS: Fifty-one studies with a total of 6553 participants were included. The overall crude recurrence rates with the various fixation techniques were: absorbable tacks, 17·5 per cent (2 treatment groups); absorbable tacks with sutures, 0·7 per cent (3); permanent tacks, 7·7 per cent (20); permanent tacks with sutures, 6·0 per cent (25); and sutures, 1·5 per cent (6). Six studies were included in a network meta-analysis, which favoured fixation with sutures. Although statistical significance was not achieved, there was a 93 per cent chance of sutures being better than one of the other methods. CONCLUSION: Both crude recurrence rates and the network meta-analysis favoured fixation with sutures during laparoscopic ventral hernia repair.

Identification of the ilioinguinal and iliohypogastric nerves during open inguinal hernia repair: a nationwide register-based study.

BACKGROUND: Chronic pain remains prevalent after open inguinal hernia repair and nerve-handling strategies are debated. Some guidelines suggest sparing nerves that are encountered; however, the nerve identification rates are unclear. This study aimed to investigate the nerve identification rates in a register-based nationwide cohort. METHODS: This study was reported according to the RECORD guideline and used prospective, routinely collected data from the Danish Hernia Database, which was linked with the National Patient Registry. We included patients ≥ 18 years old, undergoing Lichtenstein hernia repair with information on nerve handling of the iliohypogastric and ilioinguinal nerves. RESULTS: We included 30,911 open hernia repairs performed between 2012 and 2022. The ilioinguinal nerve was identified in 73% of the repairs and the iliohypogastric nerve in 66% of repairs. Both nerves were spared in more than 94% of cases where they were identified. Female patient sex, emergency and recurrence surgery, general anesthesia, medial and saddle hernias, and large defect size all result in lower nerve identification rates for both nerves. CONCLUSION: The Ilioinguinal nerve was recognized in 73% of cases, while the iliohypogastric nerve was recognized in 66% with almost all identified nerves being spared during surgery. Several pre- and intraoperative factors influenced identification rates of the ilioinguinal and iliohypogastric nerve.

Epidemiology and surgical management of 184 obturator hernias: a nationwide registry-based cohort study.

PURPOSE: We aimed describe the patient characteristics, surgical details, postoperative outcomes, and prevalence and incidence of obturator hernias. Obturator hernias are rare with high mortality and no consensus on the best surgical approach. Given their rarity, substantial data is lacking, especially related to postoperative outcomes. METHODS: The study was based on data from the nationwide Danish Hernia Database. All adults who underwent obturator hernia surgery in Denmark during 1998-2023 were included. The primary outcomes were demographic characteristics, surgical details, postoperative outcomes, and the prevalence and incidence of obturator hernias. RESULTS: We included 184 obturator hernias in 167 patients (88% females) with a median age of 77 years. Emergency surgeries constituted 42% of repairs, and 72% were laparoscopic. Mesh was used in 77% of the repairs, with sutures exclusively used in emergency repairs. Concurrent groin hernias were found in 57% of cases. Emergency surgeries had a 30-day mortality of 14%, readmission rate of 21%, and median length of stay of 6 days. Elective surgeries had a 30-day mortality of 0%, readmission rate of 10%, and median length of stay of 0 days. The prevalence of obturator hernias in hernia surgery was 0.084% (95% CI: 0.071%-0.098%), with an incidence of one per 400,000 inhabitants annually. CONCLUSIONS: This was the largest cohort study to date on obturator hernias. They were rare, affected primarily elderly women. The method of repair depends on whether the presentation is acute, and emergency repair is associated with higher mortality.

The clinical task force: Improving quality of medical students' internship.

Background: Up to 40% of young medical doctors feel that the internships prepared them insufficiently for the clinical work. This study investigated whether a Clinical Task Force (CTF) could improve internship quality. Methods: The CTF visited internship departments with a triple-targeted approach: first, departments pre-filled a self-evaluating questionnaire; secondly, CTF visited departments to discuss the self-evaluation and previous student evaluations; and thirdly, CTF and departments agreed on several quality-improving focus points to work on after the meeting. Focus points were followed-up after three and 12 months. The impact on internship quality was assessed with departments' student evaluation scores, number of completed focus points, and the effect of completed focus points on a range of learning parameters. The CTF learned several things along the way, that potentially could affect the quality of internships. A shortlist of these was provided to illustrate unmeasurable benefits. Results: The CTF met with 53 out of 60 eligible departments. The CTF and departments agreed upon 197 focus points of which 64% were completed. The three most frequent categories of focus points were Introduction of the students, The departments' evaluation percentage, and The departments' function as an educational site. The mean student evaluation scores did not change significantly, but the individual evaluation parameters changed significantly in two categories. It decreased in the category regarding the students' satisfaction with the clinical lecturers and the scheduled teaching and increased in the category regarding the percentage of students evaluating the department. Conclusion: The CTF's triple-targeted approach did not increase the mean student evaluation score significantly. For departments that completed the agreed focus points, one category increased and another decreased. However, the unmeasurable benefits illustrated that CTF was a good viable linking element between the faculty, departments, and students with the potential of improving other aspects of the quality of internships.

Lower reoperation rates after open and laparoscopic groin hernia repair when performed by high-volume surgeons: a nationwide register-based study.

PURPOSE: Previous studies have shown a correlation between surgeons with high annual volume and better outcomes after various surgical procedures. However, the preexisting literature regarding groin hernia repair and annual surgeon volume is limited. The aim was to investigate how annual surgeon volume affected the reoperation rates for recurrence after primary groin hernia repair. METHODS: This nationwide cohort study was based on data from the Danish Hernia Database and the Danish Patient Safety Authority's Online Register. Patients ≥ 18 years undergoing laparoscopic or Lichtenstein primary groin hernia repair between November 2011 and January 2020 were included. Annual surgeon volume was divided into five categories: ≤ 10, 11-25, 26-50, 51-100, and > 100 cases/year. RESULTS: We included 25,262 groin hernia repairs performed in 23,088 patients. The risk of reoperation for recurrence after Lichtenstein repair was significantly higher for the volume categories of ≤ 10 (HR 4.02), 11-25 (HR 3.64), 26-50 (HR 3.93), or 51-100 (HR 4.30), compared with the > 100 category. The risk of reoperation for recurrence after laparoscopic repair was significantly increased for the volume categories of ≤ 10 (HR 1.89), 11-25 (HR 2.08), 26-50 (HR 1.80), and 51-100 (HR 1.58) compared with the > 100 category. CONCLUSION: The risk of reoperation for recurrence was significantly higher after Lichtenstein and laparoscopic repairs performed by surgeons with < 100 cases/year compared with > 100 cases/year. This indicates that higher surgeon volume minimizes the risk of reoperation for recurrence after groin hernia repair.

Dimeric boroles: effective sources of monomeric boroles for heterocycle synthesis.

Monomeric boroles have been gaining attention as reagents for the synthesis of heterocycles due to their ability to insert atoms into the BC4 ring in a single step. Although unique boron frameworks can be accessed via this methodology, the products feature aryl substitution on the carbon centers as steric bulk is required to preclude borole dimerization. This work demonstrates that insertion chemistry is possible with Diels-Alder dimeric boroles and that such reactivity is not exclusive to monomeric boroles with bulky groups. With 1-phenyl-2,3,4,5-tetramethylborole dimer, the formal 1,1-insertion of a nitrene and sulfur generate the six-membered aromatic 1,2-azaborine and 1,2-thiaborine, respectively. The isolation of the 1,2-thiaborine enabled the synthesis of an η6-chromium complex. Benzophenone and diphenylketene readily insert a CO unit to generate BOC5 seven-membered rings confirming dimeric boroles can serve as monomeric synthons in 1,2-insertion reactions. An epoxide did not furnish the anticipated eight-membered BOC6 ring, instead provided a bicyclic system with a BOC3 ring. The insertion chemistry was demonstrated with two other borole dimers featuring different substitution with diphenylketene as a substrate. This work elevates borole insertion chemistry to a new level to access products that do not require bulky substitution.

Decreased re-operation rate for recurrence after defect closure in laparoscopic ventral hernia repair with a permanent tack fixated mesh: a nationwide cohort study.

PURPOSE: To investigate whether defect closure in laparoscopic ventral hernia repair reduces the re-operation rate for recurrence compared with no defect closure. METHODS: Data were extracted from the Danish Ventral Hernia Database. Adults with an elective laparoscopic ventral hernia repair with tacks used as mesh fixation were included, if their first repair was between the 1st of January 2007 and the 1st of January 2017. Patients with defect closure were compared with no defect closure. Re-operation rates are presented as crude rates and cumulated adjusted re-operation rates. Sub-analyses assessed the effect of the suture material used during defect closure and also whether defect closure affected both primary and incisional hernias equally. RESULTS: Among patients with absorbable tacks as mesh fixation, 443 received defect closure and 532 did not. For patients with permanent tacks, 393 had defect closure and 442 did not. For patients with permanent tacks as mesh fixation, the crude re-operation rates were 3.6% with defect closure and 7.2% without defect closure (p = 0.02). The adjusted cumulated re-operation rate was significantly reduced with defect closure and permanent tacks (hazard ratio = 0.53, 95% confidence interval = 0.28-0.999, p = 0.05). The sub-analysis suggested that defect closure was only beneficial for incisional hernias, and not primary hernias. We did not find any benefits of defect closure for patients with absorbable tacks as mesh fixation. CONCLUSION: This nationwide cohort study showed a reduced risk of re-operation for recurrence if defect closure was performed in addition to permanent tacks as mesh fixation during laparoscopic incisional hernia repair.

Biosynthesis and characterization of phosphatidylglycerophosphoglycerol, a possible intermediate in lipoteichoic acid biosynthesis in Streptococcus sanguis.

A membrane enzyme preparation from Streptococcus sanguis was shown to convert sn-[14C]glycerol 3-phosphate and CDP-diacylglycerol (or deoxyCDP-diacylglycerol) into a series of progressively higher-molecular-weight [14C]oligophosphoglycerophospholipids in vitro. The first oligophosphoglycerophospholipid to accumulate (termed lipid-1) was purified to homogeneity; chemical analysis, gas-liquid chromatography and chemical degradation studies indicated the most likely structure to be phosphatidylglycerophosphoglycerol (PGpG). PGpG is formed directly from two molecules of phosphatidylglycerol (PG), one molecule of PG serving as a sn-glycerol 1-phosphate (pG) donor and the second serving as the pG acceptor, with co-production of diacylglycerol. These oligophosphoglycerophospholipids may be intermediates in the biosynthesis of lipoteichoic acids.

New perspectives in psychiatry in the Veterans Administration.

In 1972, the mental health services in the Veterans Administration were reorganized in a manner designed to increase the probability of interdisciplinary collaboration. VA hospitals were urged to form multidisciplinary mental health committees to advise on local programs and practices. This "corporate" approach has led to significant changes in the use of staff and in the physical and psychological environment in some hospitals. While it is too early to evaluate the full impact of the changes on patient care, waiting lists have been reduced and length of hospital stay has decreased.

The stimulation of human peripheral blood lymphocytes by oral bacteria: macrophage and T-cell dependence.

Human peripheral blood mononuclear lymphocytes from individuals with moderate periodontitis were separated into purified subpopulations of T lymphocytes and B lymphocytes by rosetting with sheep red blood cells (E). All three lymphocyte subpopulations were compared for proliferative responses to cell walls from seven oral bacteria, phytohemagglutinin (PHA), pokeweed mitogen (PWM), lipopolysaccharide (LPS), and streptolysin-O (SLO). Mononuclear cells and a re-combined subpopulation consisting of four parts purified T lymphocytes and one part B lymphocytes responded significantly to all of the stimulants. Purified T lymphocytes by themselves responded significantly to PHA and PWM, but were unresponsive to oral bacteria and SLO; however, T lymphocytes cultured with 2% autologous macrophages responded significantly to all seven oral bacterial cell walls and to SLO, which indicates that T-cell responses to oral bacteria are macrophage-dependent. T-cell-depleted non-E-rosette-forming B cells by themselves were poorly responsive to all of the tested stimulants; however, the responses of these cells to oral bacteria, PWM, LPS, and SLO increased significantly in the presence of 10% mitomycin-C-treated T cells, demonstrating that B cell proliferation to these stimulants is T-cell-dependent.

The stimulation of human peripheral blood lymphocytes by solubilized dental plaque: macrophage and T-cell dependence.

This study compared the ability of human peripheral blood lymphocyte subpopulations from individuals with moderate periodontitis to proliferate in response to stimulation with solubilized dental plaque, phytohemagglutinin (PHA), pokeweed mitogen (PWM) and purified protein derivative (PPD). Unseparated mononuclear lymphocytes and recombined purified T and B lymphocytes (4/1) responded significantly to all of the stimulants. DNA synthesis in response to solubilized dental plaque was maximal after 6 to 7 days of culture; the optimum dose was usually 10 to 20 micrograms/ml. T lymphocyte subpopulations purified by rosetting with sheep red blood cells and density gradient centrifugation responded well to PHA and PWM, but were unresponsive to solubilized dental plaque and PPD unless supplemented with 2% autologous macrophages, demonstrating that T cell responses to solubilized dental plaque and to PPD are macrophage-dependent. T cell-depleted enriched B lymphocyte subpopulations were poorly responsive to all of the tested stimulants; however, the responses of these cells to solubilized dental plaque and to the known T cell-dependent B cell mitogens PWM and PPD were increased significantly by the presence of 10% mitomycin C-treated T cells, demonstrating that B cell proliferation to solubilized dental plaque is T cell-dependent. Thus, cellular interactions between macrophages, T lymphocytes and B lymphocytes are required to obtain optimal proliferative lymphocyte responses to solubilized dental plaque. Since both T and B lymphocytes respond to dental plaque stimulants, they both have the potential to mediate periodontal inflammation and tissue destruction whenever dental plaque stimulants gain entrance into the periodontal tissues.

A simple method for extracting human lymphocyte stimulants from human dental plaque bacteria of the genus Actinomyces.

The effect of acid concentration on the hot-acid extraction of antigens from Actinomyces viscosus that stimulate human peripheral blood lymphocytes in vitro was tested. The optimum pH for release of these antigens in a soluble low molecular-weight form was pH 2.3. Preliminary purification on Sepharose 4B demonstrated that most of the lympho-stimulatory material (about 90 per cent) had a mol. wt of about 100,000. This partially-purified antigenic material was mainly protein. The pH 2.3 hot-acid extraction was also suitable for extracting antigens that stimulate cellular immune responses from three strains of Actinomyces naeslundii and 1 strain of Actinomyces israelii, but did not release lympho-stimulatory material from Streptococcus sanguis which is a poor human peripheral-blood lymphocyte-stimulant and was used to demonstrate that the hot-acid extraction is not simply extracting a mitogenic macromolecule common to all bacteria. As good yields of soluble, biologically-active antigens were obtained from all of the Actinomyces, the procedure described will facilitate the purification and characterization of these antigens.

Peptidoglycan from the potentially pathogenic oral bacterium Actinomyces viscosus is a B-cell mitogen.

Cell walls and peptidoglycan from Actinomyces viscosus, strain M-100 were compared for their ability to act as mitogens with spleen cells from germ-free Fischer rats. The cell walls were prepared from trypticase soy broth grown whole cells using a French press, followed by two consecutive washes with 0.1 M tris-HCl buffer, pH 8.0, 1 M NaCl and distilled water. Peptidoglycan was prepared from cell walls by three consecutive formamide extractions at 165 degrees C. On a dry-weight basis, the peptidoglycan was a significantly-better mitogen than cell walls, suggesting that the peptidoglycan is the major mitogenic component of A. viscosus cell walls. Mononuclear spleen cells were separated on a Nylon-wool column into a non-adherent subpopulation enriched for T lymphocytes and a weakly-adherent, plunger-removable subpopulation enriched for B lymphocytes. The non-adherent T-cell subpopulation responded strongly to the T-cell mitogen PHA, but was unresponsive to both the peptidoglycan and cell walls from A. viscosus. In contrast, the weakly-adherent enriched B-cell subpopulation was less responsive to PHA, but was strongly stimulated by A. viscosus peptidoglycan and cell walls. These results indicate that peptidoglycan and cell walls from A. viscosus are B-cell mitogens.

Activation of the alternate complement pathway by peptidoglycan of Actinomyces viscosus, a potentially pathogenic oral bacterium.

Peptidoglycans and cells walls from Actinomyces viscosus, Staphylococcus aureus, and group A streptococcus were compared for their relative abilities to activate the alternate complement pathway (ACP). On the dry-weight basis, the peptidoglycan from A. viscosus was 3.5 times more active than group A streptococcal peptidoglycan and 15.6 times more active than Staph. aureus peptidoglycan in activating the ACP. Consequently A. viscosus peptidoglycan is one of the most potent ACP-activators reported to date. For both A. viscosus and group A streptococcus, the peptidoglycan was a better ACP activator than cell walls from the same organism (125- and 52-fold, respectively) indicating that the peptidoglycan is probably the most important subcellular ACP-activator in these microorganisms. In contrast, cell walls from Staph, aureus were 9 times more active than peptidoglycan from Staph. aureus in activating the ACP, presumably because teichoic acids are the most important subcellular ACP activator in this microorganism.

Transbronchial fine needle aspiration of the mediastinum. Importance of lymphocytes as an indicator of specimen adequacy.

To determine the effectiveness and accuracy of transbronchial fine needle aspiration of mediastinal masses for the staging of bronchogenic carcinoma, the results and histologic correlations of 97 transbronchial aspirates submitted from 78 patients over a two-year period were reviewed. Malignant cells were present in 25 of 97 aspirates. Of the remaining 75 nonmalignant aspirates, 34 had corresponding mediastinal tissue sections. Review of these 34 aspirates disclosed respiratory epithelial cells without lymphocytes in 20, lymphocytes without respiratory cells in 1 and both cell types in 8. Neither cell type was present in five aspirates. The predictive value of a negative result was 78% for nonmalignant aspirates containing lymphocytes and 36% for nonmalignant aspirates not containing lymphocytes (P less than .05). The presence of lymphocytes in transbronchial needle aspirates of the mediastinum is an essential criterion of specimen adequacy. Negative specimens lacking lymphocytes should be considered unsatisfactory, regardless of the numbers of respiratory epithelial cells present.

Antemortem diagnosis of cholangiocellular carcinoma in a horse.

A 10-year-old Tennessee Walking Horse gelding was admitted to the veterinary teaching hospital for evaluation of intermittent fever, lethargy, and anorexia. Initial laboratory analyses revealed anemia and hyperfibrinogenemia. Abdominocentesis and thoracentesis yielded fluid samples with high nucleated cell counts and total protein concentrations. The tentative diagnosis was nonseptic peritonitis. The horse did not improve after 4 days of antimicrobial treatment, and pitting edema of the ventral midline developed. Thoracic radiography and ultrasonography revealed consolidation of the ventral aspect of the lung fields and pleural effusion. Pleuroscopy of the right hemithorax revealed pleural effusion and a soft-tissue mass in the caudal portion of the mediastinum. Findings on biopsy of the liver and mediastinal mass led to a presumptive diagnosis of metastatic cholangiocellular carcinoma. The horse was euthanatized, and the diagnosis was confirmed at necropsy.

They may want to take charge, but can physicians really organize?

Current managed care network models include physician organizations (POs) and fully integrated regional groups (FIRGs). Proper organization of such networks requires a sequence of essential organizational decisions. If physicians are to organize properly, they must avoid three major pitfalls. Of these, the loss of autonomy is the greatest threat. The proper fit of organizational structure with the founders can assist the entire process significantly.

Activity-based costing for integrated delivery systems.

The paradigm shift toward managed care is fueling new cost-finding demands. More sophisticated methods are emerging to meet these demands. Foremost among the new methods is activity-based costing (ABC). ABC is designed to eliminate cross-subsidies between products or services. Because costs are traced by activities across departments and cost centers, costs can also be traced by activities across integrated delivery systems (IDSs). The methodology makes ABC very applicable to combinations of providers including chains, affiliated groups, and IDS participants.