Asymmetric 1,3-dipolar cycloaddition reaction of chiral 1-alkyl-1,2-diphospholes with diphenyldiazomethane

The 1,3-dipolar cycloaddition of chiral 1-alkyl-1,2-diphosphacyclopenta-2,4-dienes ((1-(−)-menthyl)oxymethyl-1,2-diphosphole and 1-(+)-neomenthyl-1,2-diphosphole) with diphenyldiazomethane leads to novel P-chiral bicyclic phosphiranes having six chiral centers. The degree of diastereoselectivity depends on the substituent at phosphorus, and dramatically increases in the case of (+)-neomenthyl group (de up to 71%). DFT calculations indicate that the cycloaddition is thermodynamically controlled.

The 1,3-dipolar cycloaddition of chiral 1-alkyl-1,2-diphosphacyclopenta-2,4-dienes with diphenyldiazomethane leads to novel P-chiral bicyclic phosphiranes having six chiral centers.     

Failure of the first step of two-stage revision due to polymicrobial prosthetic joint infection of the hip

Background

The unsuccessful treatment of prosthetic joint infection (PJI) with two-stage revision leads to infection recurrence. The objectives of the study were to assess the clinical and demographic characteristics of patients with polymicrobial PJI, and to evaluate the role of the microbial profile involved in PJI in the risk of infection recurrence after the first step of two-stage revision surgery.

Materials and methods

A retrospective analysis of 189 cases of culture-positive PJI following total hip replacement over a 5-year period was performed. The demographic characteristics of patients, clinical symptoms, microbiology cultures of intraoperative biopsies, laboratory values of C-reactive protein (CRP), white blood cell count and erythrocyte sedimentation rate were analyzed. Patients were divided into two groups—135 with monomicrobial and 54 with polymicrobial infection.

Results

Of all patients, 68.9 % in the monomicrobial and 83.3 % in the polymicrobial group had a body mass index >25 kg/m² (p = 0.05). The median CRP values were 5.7 mg/L (IQR 4.0–10.0 mg/L) in the monomicrobial compared to 8.8 mg/L (IQR 5.0–27 mg/L) in the polymicrobial group (p = 0.01). The percentage of successful outcomes was 27.8 % in patients with microbial associations (p < 0.0001). Gram-negative pathogens caused polymicrobial PJI in 61.5 % of cases with infection recurrence (OR 4.4; 95 % CI 1.18–16.37; p = 0.03).

Conclusions

Overweight and obese patients or those with elevated CRP had a greater risk of polymicrobial PJI. They were predisposed to recurrence of infection after the first step of two-stage revision. An unsuccessful outcome was more likely in cases with polymicrobial infection compared to those with monomicrobial infection. In addition, the presence of multidrug-resistant strains of Gram-negative bacteria substantially increased the risk of PJI treatment being unsuccessful.

Level of evidence

Level III, therapeutic study.

     

Altered performance of reelin-receptor ApoER2 deficient mice on spatial tasks using the Barnes maze

The apolipoprotein E receptor 2 (ApoER2), expressed predominantly in forebrain regions including the hippocampus, is 1 of 2 receptors for the extracellular matrix protein reelin, which is critical for cortical development. Previous studies of ApoER2 mutant mice have indicated deficits in synaptic plasticity and learning. The current authors assessed learning and memory of ApoER2 knockout and wild-type mice on the Barnes circular maze. Mice were trained in this task for 22 days, followed by memory recall and reversal tests. ApoER2 knockout mice were initially slower to complete the task, but by Day 22 they were more accurate than wild-type mice on several indices. There were no differences in memory assessed by the recall task, but ApoER2 knockout mice performed significantly worse on the memory reversal task. ApoER2 knockout mice also displayed altered use of specific search strategies and relationship of these strategies to errors made on the maze.     

Aetiological risk factors are associated with distinct imaging findings in patients with chronic pancreatitis: A study of 959 cases from the Scandinavian Baltic Pancreatic Club (SBPC) imaging database

ObjectivesThe relation between aetiology and structural changes of the pancreas in patients with chronic pancreatitis (CP) is not fully understood. Earlier studies are limited by focusing on selected factors in studies of limited sample size. We aimed to use a large dataset to explore associations between aetiology and pancreatic morphology in CP.MethodsSubjects with definite or probable CP according to the M-ANNHEIM diagnostic criteria were included in this multicentre cross-sectional observational study and assessed using a standardized and validated CP imaging system. We performed multivariate logistic regression to analyse if aetiological factors adjusted for covariates were independently associated with morphological pancreatic features.ResultsWe included 959 patients (66% males). Mean (SD) age was 55 (14) years. Pancreatic structural changes were found in 94% of the subjects: 67% had calcifications, 59% main pancreatic duct dilatation, 33% pseudo-cysts and 22% pancreatic atrophy. Alcohol abuse was independently associated with pancreatic calcifications (odds ratio (OR, [95% CI]); 1.61, [1.09, 2.37]) and focal acute pancreatitis (OR; 2.13, [1.27, 3.56]), whereas smoking was independently associated with more severe calcifications (OR; 2.09, [1.34, 3.27]) and involvement of the whole gland (OR; 2.29, [1.61, 3.28]). Disease duration was positively associated with calcifications (OR; (per year) 1.05 [1.02, 1.08]) and pancreatic atrophy (OR; 1.05 [1.02, 1.08]) and negatively associated with focal acute pancreatitis (OR 0.91, [0.87, 0.95] and pseudo cysts (OR; 0.96, [0.93, 0.98]).ConclusionIn this large-scale study, etiological risk factors and disease duration in CP were independently associated with specific structural pancreatic imaging changes.     

Voiding and sexual dysfunction after deep rectal resection and total mesorectal excision

OBJECTIVE: Voiding and sexual dysfunction after deep rectal resection have been described with various frequencies in the literature. In this study, we prospectively evaluated the baseline preoperative voiding and sexual function in a cohort of patients undergoing deep rectal resection with mesorectal excision to determine any pre-existing abnormalities. Postoperatively, we sought first to determine the frequency of a urinary or sexual dysfunction, secondly whether there is a time-dependent change of a dysfunction and thirdly whether there is a relationship between postoperative urological dysfunction and the patient's age. PATIENTS AND METHODS: Fifty-two patients (36 men and 16 women) with a primary rectal carcinoma were prospectively examined directly before and after the operation, as well after the third and sixth postoperative month. The preoperative urological evaluation consisted of a careful voiding and sexual history, uroflowmetry and a sonographic residual urine determination. A detailed sexual history was obtained via the use of a questionnaire. RESULTS: Urological dysfunction: Preoperatively, 49 of the 52 patients had a completely normal bladder function and three patients had post void residual >100 ml. Postoperatively, 12 of the 49 patients with normal preoperatively urinary function had voiding dysfunction, but only four male patients had residual urine in the third postoperative month. Therefore, in about 90% of the patients, postoperative bladder function became normal and only 10% suffered from vesical denervation after 6 months. We could not determine a relationship between the degree of bladder dysfunction and the patient's age due to a relatively small patient cohort in this study. Sexual dysfunction: Preoperatively, 36 (seven women, 29 men) of the 52 patients were potent and had regular sexual intercourse. Eleven men specified a limited erection, but all had occasional sexual intercourse. One of the potent men experienced no ejaculation. Postoperatively, eight of the 29 men were impotent and two of the 29 men experienced retrograde ejaculation. Therefore, 30% of the preoperatively potent men had sexual dysfunction postoperatively. There was no correlation between the postoperative impotence and the age of the patients at the time of surgery. Although it is likely that the potency may diminish with advanced age, the incidence of impotence was not higher in the older patients of our study. CONCLUSIONS: The results of our study underline the importance of risk estimation for possible postoperative urological dysfunction by means of preoperative urologic evaluation in this patient collective. Of patients with postoperative bladder dysfunction, 90% improved within 6 months after surgery and only 10% continued to have bladder dysfunction beyond 6 months, indicating irreversible nerve damage.