Misdiagnosis of mitochondrial myopathies: a study of 12 thymectomized patients

INTRODUCTION: Myasthenia gravis and mitochondrial myopathies have common symptoms (fatigability, ophthalmoplegia) that could lead to diagnosis confusion. METHODS: We systematically reviewed medical history and ancillary investigations regarding 12 patients (7F/5M, mean age 47+/-14 years) having a mitochondrial myopathy but who were previously misdiagnosed as autoimmune myasthenia gravis and in whom a thymectomy was performed. RESULTS: Ocular palsy, ptosis and bulbar palsy were present in all patients. Limb fatigability was present in 9 cases. Symptoms were fluctuant but without remission. The misdiagnosis of myasthenia was based on the following arguments: 1) decremental EMG response (2 cases); 2) positive injectable anticholinesterase drugs test (3 cases); 3) partial response to oral anticholinesterase medications (2 cases); 4) AChR antibodies titer of 0.6 nM considered as positive (1 case). A multisystemic involvement was present in 5 patients: peripheral neuropathy (2 cases), deafness (2 cases), cardiopathy (3 cases), cerebellar involvement (2 cases) and myoclonia (1 case). The diagnosis of mitochondrial myopathy (at a mean age of 38+/-12 years) has been certified on the results of muscle biopsy showing mitochondrial proliferation (12 cases) and deleted mitochondrial DNA (8 cases). CONCLUSIONS: In a patient presenting with oculomotor symptoms and muscle fatigability, progressive course and multisystemic involvement are major arguments for a mitochondrial myopathy. In the absence of relevant criteria arguing for Myasthenia Gravis (significant variability of muscle weakness, positive titer of anti-AChR or anti-MuSK antibodies, decremental EMG response), a muscle biopsy is required before indication of thymectomy to exclude a mitochondrial disease.     

Does the surgical technique for management of the distal ureter influence the outcome after nephroureterectomy?

Study Type – Therapy (case series)
Level of Evidence 4 What’s known on the subject? and What does the study add? The resection of the distal ureter and its orifice is an oncological principle during radical nephroureterectomy which is based on the fact that it represents a part of the urinary tract exposed to a considerable risk of recurrence. After removal of the proximal part it is hardly possible to image or approach it by endoscopy during follow‐up. Recent publications on survival after nephroureterectomy do not allow the conclusion that removal of distal ureter and bladder cuff are useless. Several techniques of distal ureter removal have been described but they are not equivalent in term of oncological safety. ? The standard treatment of upper urinary tract urothelial carcinomas (UUT‐UCs) must obey oncological principles, which consist of a complete en bloc resection of the kidney and the ureter, as well as excision of a bladder cuff to avoid tumour seeding. ? The open technique is the ‘gold standard’ of treatment to which all other techniques developed are necessarily compared, and various surgical procedures have been described. ? The laparoscopic stapling technique maintains a closed system but risks leaving behind the ureteric and bladder cuff segments. ? Transvesical laparoscopic detachment and ligation is a valid approach from an oncological stance but is technically difficult. The major inconvenience of the transurethral resection of the ureteric orifice and intussusception techniques is the potential for tumour seeding. ? Management of the distal ureter via the robot‐assisted laparoscopic method is technically feasible, but outcomes from these procedures are still preliminary. ? Therefore, prospective comparative studies with more thorough explorations of these techniques are needed to solve the dilemma of the management of the distal ureter during nephroureterectomy. However, bladder cuff excision should remain the standard of care irrespective of the stage of the disease.     

Aminobisphosphonates Cause Osteoblast Apoptosis and Inhibit Bone Nodule Formation In Vitro

Bisphosphonates are widely used for the treatment of bone diseases associated with increased osteoclastic bone resorption. Bisphosphonates are known to inhibit biochemical markers of bone formation in vivo, but it is unclear to what extent this is a consequence of osteoclast inhibition or a direct inhibitory effect on cells of the osteoblast lineage. In order to investigate this issue, we studied the effects of various bisphosphonates on osteoblast growth and differentiation in vitro. The aminobisphosphonates pamidronate and alendronate inhibited osteoblast growth, caused osteoblast apoptosis, and inhibited protein prenylation in osteoblasts in a dose-dependent manner over the concentration range 20-100 microM. Further studies showed that alendronate in a dose of 0.1 mg/kg inhibited protein prenylation in calvarial osteoblasts in vivo, indicating that alendronate can be taken up by osteoblasts in sufficient amounts to inhibit protein prenylation at clinically relevant doses. Pamidronate and alendronate inhibited bone nodule formation at concentrations 10-fold lower than those required to inhibit osteoblast growth. These effects were not observed with non-nitrogen-containing bisphosphonates or with other inhibitors of protein prenylation and were only partially reversed by cotreatment with a fourfold molar excess of ss-glycerol phosphate. We conclude that aminobisphosphonates cause osteoblast apoptosis in vitro at micromolar concentrations and inhibit osteoblast differentiation at nanomolar concentrations by mechanisms that are independent of effects on protein prenylation and may be due in part to inhibition of mineralization. While these results need to be interpreted with caution because of uncertainty about the concentrations of bisphosphonates that osteoblasts are exposed to in vivo, our studies clearly demonstrate that bisphosphonates exert strong inhibitory effects on cells of the osteoblast lineage at similar concentrations to those that cause osteoclast inhibition. This raises the possibility that inhibition of bone formation by bisphosphonates may be due in part to a direct inhibitory effect on cells of the osteoblast lineage.     

Minimum Alveolar Concentration of Volatile Anesthetics in Rats during Postnatal Maturation

Background: Although neonatal rats have become widely used as experimental laboratory animals, minimum alveolar concentration (MAC) values of volatile anesthetics in rats during postnatal maturation remain unknown.

Methods: We determined MAC values of volatile anesthetics in spontaneously breathing neonatal (2-, 9-, and 30-day-old) and adult Wistar rats exposed to increasing (in 0.1-0.2% steps) concentrations of halothane, isoflurane, or sevoflurane (n = 12-20 in each group), using the tail-clamp technique. MAC and its 95% confidence intervals were calculated using logistic regression and corrected for body temperature (37[degrees]C).

Results: In adult rats, inspired MAC values corrected at 37[degrees]C were as follows: halothane, 0.88% (confidence interval, 0.82-0.93%); isoflurane, 1.12% (1.07-1.18%); and sevoflurane, 1.97% (1.84-2.10%). In 30-day-old rats, the values were as follows: halothane, 1.14% (1.07-1.20%); isoflurane, 1.67% (1.58-1.76%); and sevoflurane, 2.95% (2.75-3.15%). In 9-day-old rats, inspired MAC values were as follows: halothane, 1.68% (1.58-1.78%); isoflurane, 2.34% (2.21-2.47%); and sevoflurane, 3.74% (3.64-3.86%). In 2-day-old rats, inspired MAC values were as follows: halothane, 1.54% (1.44-1.64%); isoflurane, 1.86% (1.72-2.01%); and sevoflurane, 3.28% (3.09-3.47%).     

The response of balanitis xerotica obliterans to local steroid application compared with placebo in children

PURPOSE: We evaluated the clinical effectiveness of topical steroid application for balanitis xerotica obliterans in children and analyzed the association of any clinical response with histological findings. MATERIALS AND METHODS: Our double-blind, placebo controlled, randomized study included 40 boys in whom balanitis xerotica obliterans was diagnosed clinically by cicatricial phimosis. The severity of phimosis was graded into 4 groups. Patients were randomized to receive the topical application of 0.05% mometasone furoate or placebo. After 5 weeks phimosis severity was reevaluated and all patients underwent circumcision. Surgical specimens were histologically typed as an early, intermediate or late form of balanitis xerotica obliterans. RESULTS: Seven patients were withdrawn from the study. In the steroid group 7 boys had clinical improvement and 10 had no change. Histological study showed an early, intermediate and late form of balanitis xerotica obliterans in 5, 5 and 7 cases, respectively. Of cases with clinical improvement 5 were the early and 2 the intermediate type. In the placebo group 5 cases worsened clinically and 11 did not change. Histological evaluation revealed an early, intermediate and late form of balanitis xerotica obliterans in 3, 7 and 6 boys, respectively. Of the 5 cases with histological worsening, disease was the early, intermediate and late type in 2, 2 and 1, respectively. CONCLUSIONS: Applying a potent topical steroid affects improvement in balanitis xerotica obliterans in the histologically early and intermediate stages of disease, and may inhibit further worsening in the late stage.     

Poor Outcomes After Liver Transplantation in Patients With Incidental Cholangiocarcinoma Irrespective of Tumor Localization

Introduction

After liver transplantation for cholangiocarcinoma (CCC), patients have a poor prognosis without use of specific therapeutic strategies. Accordingly, recipients with incidental CCC might have the highest risk of recurrent disease; however, sparse data on the long-term outcome of unselected patients with incidental CCC have been published. The aim of this study was to evaluate the post-transplantation outcomes of patients with incidental CCC with special focus on tumor localization.

Material and Methods

There were 11 primary liver transplantations in patients with incidental CCC of 1310 liver transplantation procedures performed between December 1994 and August 2013. All patients with incidental CCC received a chemotherapy regiment including gemcitabine/5 fluorouracil, doxorubicin, and mitomycin. The patients were switched from calcineurin inhibitors to mammalian target of rapamycin inhibitor−based immunosuppression shortly after CCC diagnosis.

Results

Intra- and extrahepatic tumors were found in 6 and 5 patients, respectively. At median follow-up examination of 26.3 months there were 8 CCC recurrences and 7 patient deaths. Overall survival after liver transplantation for incidental CCC was 88.9% at 1 year, 44.4% at 2 years, and 14.8% at 3 years. The corresponding rates of recurrence-free survival were 45.7%, 45.7%, and 0.0%, respectively. Post-transplantation CCC recurrences were universal with 0% 3-year recurrence-free survival both in patients with intra- and extrahepatic tumors (P = .475).

Conclusions

Incidental CCC in liver transplantation is associated with poor outcomes irrespective of tumor localization. Introduction of new adjuvant multimodal treatment concepts is necessary to improve the prognosis for this subgroup of patients.     

Initial prevalence of anal human papilloma virus infection in liver transplant recipients

Although liver transplant recipients are at increased risk of human papilloma virus (HPV)‐related anal cancer, limited data are available regarding the initial prevalence of anal HPV infection in this population. Anal swabs collected from 50 liver transplant recipients within the first three postoperative weeks were subjected to real‐time polymerase chain reaction for detection of the four HPV genotypes: 6, 11, 16, and 18. Predictors of any, low‐risk, and high‐risk anal HPV infection were evaluated. Overall, the prevalence of any anal HPV infection was 18.0%, with the corresponding rates for high‐ and low‐risk HPV genotypes being 8.0% and 10.0%, respectively. Infection with any type of anal HPV was higher in patients with hepatitis B virus (HBV) infection (P = 0.027), ≥3 sexual partners (P = 0.031), and alcoholic liver disease (P = 0.063). HBV infection was the only factor significantly associated with high‐risk HPV infection (P = 0.038). Male sex (P = 0.050), age ≥52 years (P = 0.016), ≥30 sexual partners (P = 0.003), age at first intercourse ≤18 years (P = 0.045), and time since first intercourse ≥38 years (P = 0.012) were identified as predictors of low‐risk HPV infection. These results indicate that HPV vaccination of liver transplant candidates and screening for anal HPV infection in high‐risk groups should be considered.