Patterns of healing of scaphoid fractures. The importance of vascularity

We studied 45 patients with 46 fractures of the scaphoid who presented sequentially over a period of 21 months. MRI enabled us to relate the pattern of the fracture to the blood supply of the scaphoid. Serial MRI studies of the four main patterns showed that each followed a constant sequence during healing and failure to progress normally predicted nonunion.     

Extradural endodermal cyst of posterior fossa: case report, review of the literature, and embryogenesis

OBJECTIVE AND IMPORTANCE: Posterior fossa endodermal cysts are rare. They are located in the midline, in ventral or ventrolateral locations, or intrinsic to the neural axis. Accordingly, various theories of embryogenesis have been proposed. We report the first case of an extradural, dorsolaterally situated endodermal cyst. CLINICAL PRESENTATION: An adult male patient presented with a short history of headache and cerebellar ataxia. Neuroimaging revealed an extra-axial cystic posterior fossa mass. INTERVENTION: An entirely extradural cyst was found and was totally excised. Immunohistochemistry confirmed the diagnosis of endodermal cyst. CONCLUSION: The extradural, dorsal location of the endodermal cyst suggests gaps at the cranial end of the notochord causing ectodermal-endodermal adhesions during early gastrulation and the persistence of endodermal remnants in the dorsal mesenchyme of the blastemal cranium. The literature is reviewed, and proposed theories of embryogenesis are discussed.     

Pharmacological studies on nitro‐naproxen (naproxen‐2‐nitrooxyethylester)

Naproxen‐2‐nitrooxyethylester (S‐(+)‐2‐(6‐methoxy‐2‐naphthyl)propanoic acid‐2‐nitrooxyethylester, LE‐EK06) was synthesized from naproxen and 2‐nitrooxyethylbromide as a novel nitric oxide–releasing derivative of naproxen. Molar equivalents of LE‐EK06 (6.93–27.73 mg/kg, p.o.) to naproxen dose‐dependently exhibited greater antinociceptive activity in comparison to naproxen in a writhing assay. The compound (5.54–22.18 mg/kg, p.o.) showed greater anti‐inflammatory activity at 2 h after as comparable to its effect at 4 h after carrageenan challenge in rats. Further, LE‐EK06 (9.45 mg/kg, p.o.) was more potent in the carrageenan‐evoked hyperalgesia. LE‐EK06 (11.09 mg/kg, p.o.) and naproxen (8.0 mg/kg, p.o.) showed a comparable inhibitory effect on exudate formation and migration of polymorphonuclear leukocytes (PMNs) in a carrageenan‐induced pleurisy test. Further, the compound (11.09 mg/kg, p.o.) significantly reduced myeloperoxidase activity in carrageenan‐treated paw and demonstrated significantly less gastrotoxicity in acute and chronic (21 days) studies. The scanning electron microscopy revealed that LE‐EK06 showed only mild gastric damage (slight disruption of mucus layer) in comparison to naproxen. The present study suggested that naproxen‐2‐nitrooxyethylester (LE‐EK06) represents a novel gastric sparing NSAID. Drug Dev. Res. 61:66–78, 2004. © 2004 Wiley‐Liss, Inc.     

Hemimegalencephaly with tuberous sclerosis: A longitudinal imaging study

Hemimegalencephaly is a rare cerebral malformation characterized by asymmetry of the hemispheres and cortical dysplasias. We report clinical and imaging findings in a child with hemimegalencephaly involving the right cerebral hemisphere with associated manifestations of tuberous sclerosis complex. Gross abnormal myelination pattern and gyral abnormalities were seen in the enlarged hemisphere. Subsequent scans showed atrophy of the frontoparietal region in the enlarged hemisphere and normal growth of the opposite hemisphere exceeding the size of the abnormal hemisphere in the frontoparietal region. A few white‐matter lesions that were seen in the normal hemisphere on neonatal scan were difficult to appreciate on subsequent MR studies. The white‐matter lesions were better seen in the neonatal period, whereas cortical tubers were better detected at a later age.     

Brief Clinical Report: Serum Tumor Necrosis Factor for Monitoring Response of Hepatic Veno-occlusive Disease to Pentoxiphyllin-A Case Report

Hepatic veno-occlusive disease (VOD) is the second most common cause of death after autologous bone marrow transplantation (ABMT). A patient with multiple myeloma undergoing ABMT developed classic features of hepatic VOD. He responded to treatment with pentoxiphyllin. Serum tumor necrosis factor (TNF) levels showed remarkable correlation with the severity of VOD and response to therapy.     

A model to explore the interaction between muscle insulin resistance and beta-cell dysfunction in the development of type 2 diabetes

Type 2 diabetes is a polygenic disease characterized by defects in both insulin secretion and insulin action. We have previously reported that isolated insulin resistance in muscle by a tissue-specific insulin receptor knockout (MIRKO mouse) is not sufficient to alter glucose homeostasis, whereas beta-cell-specific insulin receptor knockout (betaIRKO) mice manifest severe progressive glucose intolerance due to loss of glucose-stimulated acute-phase insulin release. To explore the interaction between insulin resistance in muscle and altered insulin secretion, we created a double tissue-specific insulin receptor knockout in these tissues. Surprisingly, betaIRKO-MIRKO mice show an improvement rather than a deterioration of glucose tolerance when compared to betaIRKO mice. This is due to improved glucose-stimulated acute insulin release and redistribution of substrates with increased glucose uptake in adipose tissue and liver in vivo, without a significant decrease in muscle glucose uptake. Thus, insulin resistance in muscle leads to improved glucose-stimulated first-phase insulin secretion from beta-cells and shunting of substrates to nonmuscle tissues, collectively leading to improved glucose tolerance. These data suggest that muscle, either via changes in substrate availability or by acting as an endocrine tissue, communicates with and regulates insulin sensitivity in other tissues.