Lumbar hernia, anatomical basis and clinical aspects

INTRODUCTION: The purpose of this study was to describe the anatomy of the two orifices of the abdominal posterior wall where lumbar hernias could appear. They may protrude through the superficial lumbar triangle (JL Petit) or the deepest superior orifice (Grynfeltt). METHODS: The exact limits were precised by dissections in cadavers to explain the main differences of these two locations. We report two cases of spontaneous lumbar hernias discovered in outpatient clinic. RESULTS: Clinical diagnosis was difficult and both the patients were sent for lumbar lipoma but a meticulous examination gave us a clue. MRI was useful to confirm the defect in the posterior abdominal wall under the 12th rib. Only one patient was operated by a direct approach with a reinforcement of an unabsorbable mesh. No recurrence appeared during follow-up. CONCLUSION: Thanks to clinical and anatomical knowledge, these rare superior lumbar hernias were diagnosed and a correct surgical treatment permitted a quick recovery.     

Murine intramyocellular lipids quantified by NMR act as metabolic biomarkers in burn trauma

It has been suggested that intramyocellular lipids (IMCLs) may serve as biomarkers of insulin resistance and mitochondrial dysfunction. Using a hind-limb mouse model of burn trauma, we tested the hypothesis that severe localized burn trauma involving 5% of the total body surface area causes a local increase in IMCLs in the leg skeletal muscle. We quantified IMCLs from ex vivo intact tissue specimens using High-Resolution Magic Angle Spinning (HRMAS) 1H NMR and characterized the accompanying gene expression patterns in burned versus control skeletal muscle specimens. We also quantified plasma-free fatty acids (FFAs) in burn versus control mice. Our results from HRMAS 1H NMR measurements indicated that IMCL levels were significantly increased in mice exposed to burn trauma. Furthermore, plasma FFA levels were also significantly increased, and gene expression of Glut4, insulin receptor substrate 1 (IRS1), glycolytic genes, and PGC-1beta was downregulated in these mice. Backward stepwise multiple linear regression analysis demonstrated that IMCL levels correlated significantly with FFA levels, which were a significant predictor of IRS1 and PGC-1beta gene expression. We conclude from these findings that IMCLs can serve as metabolic biomarkers in burn trauma and that FFAs and IMCLs may signal altered metabolic gene expression. This signaling may result in the observed burn-induced insulin resistance and skeletal muscle mitochondrial dysfunction. We believe that IMCLs may therefore be useful biomarkers in predicting the therapeutic effectiveness of hypolipidemic agents for patients with severe burns.     

Reduced rate of adenosine triphosphate synthesis by in vivo 31P nuclear magnetic resonance spectroscopy and downregulation of PGC-1beta in distal skeletal muscle following burn

Using a mouse model of burn trauma, we tested the hypothesis that severe burn trauma corresponding to 30% of total body surface area (TBSA) causes reduction in adenosine triphosphate (ATP) synthesis in distal skeletal muscle. We employed in vivo 31P nuclear magnetic resonance (NMR) in intact mice to assess the rate of ATP synthesis, and characterized the concomitant gene expression patterns in skeletal muscle in burned (30% TBSA) versus control mice. Our NMR results showed a significantly reduced rate of ATP synthesis and were complemented by genomic results showing downregulation of the ATP synthase mitochondrial F1 F0 complex and PGC-1beta gene expression. Our findings suggest that inflammation and muscle atrophy in burns are due to a reduced ATP synthesis rate that may be regulated upstream by PGC-1beta. These findings implicate mitochondrial dysfunction in distal skeletal muscle following burn injury. That PGC-1beta is a highly inducible factor in most tissues and responds to common calcium and cyclic adenosine monophosphate (cAMP) signaling pathways strongly suggests that it may be possible to develop drugs that can induce PGC-1beta.     

A review of anatomy education during and after the COVID‐19 pandemic: Revisiting traditional and modern methods to achieve future innovation

The coronavirus disease 2019 (COVID‐19) pandemic has had enormous effects on anatomy education. During the pandemic, students have had no access to cadavers, which has been the principal way to learn anatomy since the 17th century. As it is difficult to predict future access to cadavers for students or in‐person classes, anatomy educators are encouraged to revisit all possible teaching methods in order to develop innovations. Here, we review anatomy education methods to apply to current and future education.     

Comparing the left and right Whitnall’s tubercles and their relation to the frontozygomatic suture: Application to symmetry following lateral orbital surgery

We compare, on left and right side of human skulls, the length of Whitnall’s tubercle as a relevant landmark and anchor point for the lateral retinaculum. Twenty human skulls were used in this study. A caliper was used to measure the length of Whitnall’s tubercle, the distance from Whitnall’s tubercle to the frontozygomatic suture and the height of the orbit. An overall mean for these three parameters was calculated using the data obtained. There were no significant differences between left and the right sides. The combined mean length of Whitnall’s tubercle was 4.9 mm ± 23%. The combined mean distance from the frontozygomatic suture was 7.8 mm ± 25%. The orbital height was found to be the measurement with the highest congruence between the two sides having a combined mean of 32.3 mm ± 7%. Although 6 out of 20 skulls were found to have no tubercle, five out of twenty skulls had a tubercle only on one side. Even though human skulls develop from bilateral symmetric osteogenesis, surgeons should always be aware of possible asymmetry and possible absence of Whitnall’s tubercle between sides or among individuals. The frontozygomatic suture was found to be a useful landmark in identifying the position of Whitnall’s tubercle in the majority of specimens. Such information will be useful in realigning the lateral retinaculum following surgery.     

Cholesterol catabolism in patients with acute myelogenous leukemia and hypocholesterolemia: suppressed levels of a circulating marker for bile acid synthesis

Hypocholesterolemia is a frequent finding in patients with acute myelogenous leukemia (AML) and in other types of malignancies. Since bile acids are major excretion products of cholesterol, the hepatic degradation of cholesterol to bile acids was investigated in AML patients by analyzing a circulating marker for bile acid synthesis. In addition, plasma levels of a marker for cholesterol synthesis were determined. The plasma levels of 7-hydroxy-4-cholesten-3-one, reflecting bile acid production, were markedly lower in patients with AML than in healthy controls. The median levels were 3.3 and 18.5 ng/ml (P<0.0001) in the AML patients (n=29) and the healthy subjects (n=16), respectively. The plasma levels of 7-dehydrocholesterol, reflecting hepatic cholesterol synthesis, were similar for the AML patients and the controls. The results show that the conversion of cholesterol to bile acids was suppressed in AML patients, a phenomenon that may result in a decreased intestinal absorption of cholesterol and subsequent hypocholesterolemia.