The danger of chlorhexidine in lignocaine gel: A case report of anaphylaxis during urinary catheterisation

This article describes a case of anaphylaxis secondary to chlorhexidine during urethral catheterisation. Despite little evidence for the use of antiseptic lubricants in preventing catheter-associated urinary tract infections, the distribution and use of such products continues to be widespread. Chlorhexidine-free lubricating gel is widely available and should be used for urological procedures wherever possible.     

C.B‐17 SCID mice develop epicardial calcinosis with unaltered cardiac function

Inbred mouse strains are the most widely used mammalian model organism in biomedical research owing to ease of genetic manipulation and short lifespan; however, each inbred strain possesses a unique repertoire of deleterious homozygous alleles that can make a specific strain more susceptible to a particular disease. In the current study, we report dystrophic cardiac calcinosis (DCC) in C.B‐17 SCID male mice at 10 weeks of age with no significant change in cardiac function. Acquisition of DCC was characterized by myocardial injury, fibrosis, calcification, and necrosis of the tissue. At 10 weeks of age, 38% of the C.B‐17 SCID mice from two different commercial colonies exhibited significant calcinosis on the ventricular epicardium, predominantly on the right ventricle. The frequency of calcinosis was more than 50% for mice obtained from Taconic's Cambridge City colony and 25% for mice obtained from Taconic's German Town colony. Interestingly, the DCC phenotype did not affect cardiac function at 10 weeks of age. No differences in echocardiography or electrocardiography were observed between the calcinotic and non‐calcinotic mice from either colony. Our findings suggest that C.B‐17 SCID mice exhibit DCC as early as 10 weeks of age with no significant impact on cardiac function. This strain of mice should be cautiously considered for the study of cardiac physiology.     

Characterization of infections and hypogammaglobulinemia treated with the combination of pertuzumab and trastuzumab

We update a patient series that reported a high incidence of infection with Gram-positive cocci in women treated with the combination of pertuzumab and trastuzumab and further characterize this clinical problem. Treating physicians and advanced practice partners identified women who developed infections while on treatment with pertuzumab and trastuzumab alone or in combination with chemotherapy and enrolled them onto this registry trial. Between March, 2014 and May, 2017, 48 patients with HER2-positive breast cancers were reported to have 59 individual infections. The median age was 48 years. Twenty-four patients received neoadjuvant therapy, 17 were treated for metastatic disease, and 7 were treated in the adjuvant setting. Pertuzumab and trastuzumab were combined with carboplatin and docetaxel in 24 (49%) patients, docetaxel in 10 (21%), nab-paclitaxel in 12 (24%), and without other agents in 2 (4%). Granulocyte growth factors were administered in 24 (49%) patients and no patients were documented to be neutropenic. Folliculitis developed in 25 (52%) patients and was counted as a single infection. Abscesses developed at a number of sites in 24 (49%) patients, including a septic knee requiring total knee replacement. Paronychia occurred in 7 (15%) patients, and 5 (10%) developed cellulitis. When cultures were obtained, Gram-positive cocci were consistently identified. Hypogammaglobulinemia was documented in 14 (36%) of the 33 patients tested. Our data continue to support an increased risk of infections with Gram-positive cocci as a potentially serious adverse event in women treated with pertuzumab and trastuzumab.     

Neuronal protein-tyrosine phosphatase 1B hinders sensory-motor functional recovery and causes affective disorders in two different focal ischemic stroke models

Ischemic brain injury causes neuronal death and inflammation. Inflammation activates protein-tyrosine phosphatase 1B (PTP1B). Here, we tested the significance of PTP1B activation in glutamatergic projection neurons on functional recovery in two models of stroke: by photothrombosis, focal ischemic lesions were induced in the sensorimotor cortex (SM stroke) or in the peri-prefrontal cortex (peri-PFC stroke). Elevated PTP1B expression was detected at 4 days and up to 6 weeks after stroke. While ablation of PTP1B in neurons of neuronal knockout (NKO) mice had no effect on the volume or resorption of ischemic lesions, markedly different effects on functional recovery were observed. SM stroke caused severe sensory and motor deficits (adhesive removal test) in wild type and NKO mice at 4 days, but NKO mice showed drastically improved sensory and motor functional recovery at 8 days. In addition, peri-PFC stroke caused anxiety-like behaviors (elevated plus maze and open field tests), and depression-like behaviors (forced swimming and tail suspension tests) in wild type mice 9 and 28 days after stroke, respectively, with minimal effect on sensory and motor function. Peri-PFC stroke-induced affective disorders were associated with fewer active (FosB⁺) neurons in the PFC and nucleus accumbens but more FosB⁺ neurons in the basolateral amygdala, compared to sham-operated mice. In contrast, mice with neuronal ablation of PTP1B were protected from anxiety-like and depression-like behaviors and showed no change in FosB⁺ neurons after peri-PFC stroke. Taken together, our study identifies neuronal PTP1B as a key component that hinders sensory and motor functional recovery and also contributes to the development of anxiety-like and depression-like behaviors after stroke. Thus, PTP1B may represent a novel therapeutic target to improve stroke recovery. All procedures for animal use were approved by the Animal Care and Use Committee of the University of Ottawa Animal Care and Veterinary Service (protocol 1806) on July 27, 2018.Key Words: adhesive removal test, anxiety, depression, elevated plus maze, forced swimming test, Iba1, interleukin-1β, microglia, open field test, tail suspension test, tumor necrosis factor-α

Chinese Library Classification No. R453; R741; R364.5     

Vacuum-assisted closure therapy in pyoderma gangrenosum

Vacuum-assisted closure (VAC), although a modern adjunct in wound management, has not been used previously in pyoderma gangrenosum (PG), probably to avoid the potential complications of ‘pathergy’. We would like to report our experience of VAC in three cases of PG with the relevant review of literature.     

Delayed and persistent suppression of bronchoconstriction by trypsin in the airway lumen.

Mucosal trypsin, a protease-activated receptor (PAR) stimulant, may have an endogenous bronchoprotective role on airway smooth muscle. To test this possibility the effects of lumenal trypsin on airway tone in segments of pig bronchus were tested. Bronchial segments from pigs were mounted in an organ chamber containing Kreb's solution. Contractions were assessed from isovolumetric lumen pressure induced by acetylcholine (ACh) or carbachol added to the adventitia. Trypsin, added to the airway lumen (300 microg x mL(-1)), had no immediate effect on smooth muscle tone but suppressed ACh-induced contractions after 60 min, for at least 3 h. Synthetic activating peptides (AP) for PAR1, PAR2 or PAR3 were without effect, but PAR4 AP caused rapid, weak suppression of contractions. Lumenal thrombin was without effect and did not prevent the effects of trypsin. Effects of trypsin were reduced by N(omega)-nitro-L-arginine methyl ester but not indomethacin. Trypsin, thrombin and PAR4 AP released prostaglandin E2. Adventitially, trypsin, thrombin and PAR4 AP (but not PAR2 AP) relaxed carbachol-toned airways after <3 min. The findings of this study show that trypsin causes delayed and persistent bronchoprotection by interacting with airway cells accessible from the lumen. The signalling mechanism may involve nitric oxide synthase but not prostanoids or protease-activated receptors.