Muscle specific kinase autoantibodies cause synaptic failure through progressive wastage of postsynaptic acetylcholine receptors

In myasthenia gravis muscle weakness is caused by autoantibodies against components of the neuromuscular junction. Patient autoantibodies against muscle specific kinase (MuSK) deplete MuSK from the postsynaptic membrane and reproduce signs of myasthenia gravis when injected into mice. Here we have examined the time-course of structural and functional changes that lead up to synaptic failure. C57Bl6J mice received daily injections of anti-MuSK patient IgG for 15days. Mice began to lose weight from day 12 and demonstrated whole-body weakness by day 14. Electromyography indicated synaptic impairment from day 6 in the gastrocnemius muscle and from day 10 in the diaphragm muscle. Confocal microscopy revealed linear declines in the area and density of postsynaptic acetylcholine receptors (3-5% per day) from day 1 through day 15 of the injection series in all five muscles examined. Intracellular recordings from the diaphragm muscle revealed comparable progressive declines in the amplitude of the endplate potential and miniature endplate potential of 3-4% per day. Neither quantal content nor the postsynaptic action potential threshold changed significantly over the injection series. The inverse relationship between the quantal amplitude of a synapse and its quantal content disappeared only late in the injection series (day 10). Our results suggest that the primary myasthenogenic action of anti-MuSK IgG is to cause wastage of postsynaptic acetylcholine receptor density. Consequent reductions in endplate potential amplitudes culminated in failure of neuromuscular transmission.     

Trastuzumab mediated cardiotoxicity in the setting of adjuvant chemotherapy for breast cancer: a retrospective study

Background The incidence and management of trastuzumab-mediated cardiotoxicity outside of clinical trials has not been well described. Objective and methods The aim of the study was to retrospectively evaluate the incidence of cardiac dysfunction, characterize its natural history, and identify the degree of reversibility using cardiac MRI, in a population of HER-2 positive breast cancer patients receiving trastuzumab in the adjuvant setting. Results Out of 152 patients (mean age 52 ± 10 years), 36 (24%) developed trastuzumab mediated cardiomyopathy, the majority asymptomatic. Factors that predicted the development of trastuzumab mediated cardiac dysfunction were a pre-existing history of hypertension, smoking history, and a family history of coronary artery disease. Within 3 months of treatment with trastuzumab, there was a difference in LVEF between the normal cohort and those patients who developed LV systolic dysfunction (61 ± 5% vs. 51 ± 8%, P < 0.01). During the 6-month-followup, 34/36 patients demonstrated subepicardial linear delayed enhancement of the lateral wall of the left ventricle on cardiac MRI, suggesting trastuzumab induced myocarditis. Conclusion Approximately 1 in 4 women may develop LV systolic dysfunction after treatment with adjuvant trastuzumab, necessitating careful patient selection and close serial monitoring using noninvasive cardiac imaging.     

Preinjection aspiration for injectable fillers in aesthetic dermatology: Trust or bust?

In recent years, the utility of preinjection aspiration for injectable fillers as a safety checkpoint has been debated. It is a clinical technique that has become controversial in both the literature and at national aesthetic conferences. Many consensus papers and anecdotal reports have been divided on how helpful preinjection aspiration is in reducing adverse events and subsequently increasing patient safety. Here, we summarize the prominent studies in the literature and offer an evaluation and insights.     

Erroneous diagnosis of primary fibrosarcoma of the breast: The value of the multidisciplinary breast team approach

Diagnostic errors occur in the preanalytic, analytic, and postanalytic phases of specimen processing. Correlating clinical and imaging information with gross and microscopic findings is crucial to limit errors and unnecessary treatment. Herein, we report the case of a 54-year-old woman who presented with left breast bloody nipple discharge and subsequently underwent central duct excision. Pathology revealed a high-grade sarcoma. The patient presented to our institution for further management. Upon secondary pathology review and DNA fingerprinting analysis, the correct interpretation was rendered. Our case demonstrates the importance of clinical correlation and review of pathology slides prior to definitive therapy.     

Evaluating the Correlation Between the Survival Rate of Patients with Esophageal Squamous Cell Carcinoma and Expression of p53 and Cyclin D1 Biomarkers Along with Other Prognostic Factors

Objective

In the present study, we aimed to evaluate the relationship between the survival rate of patients with esophageal squamous cell carcinoma (SCC) and expression of two biomarkers along with age, gender, tumor margin, depth of invasion, site of tumor, tumor diameter, tumor grade, number of involved nodes, and vascular invasion.

Materials and Methods

In this retrospective survey, medical records of patients referred to the Shohada-e Tajrish hospital during 2001 to 2005 were reviewed and subjects with definite diagnosis of SCC were included. Required data were extracted from the patients’ records, and their prepared paraffin-embedded tissue blocks were collected under supervision of two pathologists. Immunohistochemistry (IHC) analysis was performed at the Firoozgar hospital in Tehran, Iran.

Results

The studied population included 20 men (74%) and 7 women (26%). The mean age at diagnosis was 58 ± 22. Results showed significantly higher survival rates in women compared to men (85.7 vs. 40%) (p = 0.001) and in patients with well-differentiated tumors compared to poor-differentiated cases (20 vs. 5%) (p = 0.004). No significant relationship was found between p53 expression and prognostic factors like age, gender, the site, grade, and size of the tumor, depth of invasion, involvement of lymph nodes, and vascular invasion.

Conclusion

Positivity of p53 and cyclin D1 was not found to be predictive of survival in patients with esophageal SCC which might be due to the small sample size of the present survey. Further investigations with larger sample populations and longer follow-ups are required to evaluate this correlation.

     

Correlation of Neutrophil to Lymphocyte Ratio and Absolute Neutrophil Count With Outcomes With PD-1 Axis Inhibitors in Patients With Advanced Non–Small-Cell Lung Cancer

Introduction

Programmed death-1 (PD-1) axis inhibitors have become standard therapy in advanced non–small-cell lung cancer (NSCLC). Response might be delayed and pseudo-progression occasionally occurs in patients who eventually benefit from treatment. Additional markers beyond programmed death ligand 1 (PD-L1) expression are needed to assist in patient selection, response evaluation, and treatment decisions.