Citations

Age increases the risk for ischemic acute kidney injury (AKI). We questioned whether a similar age-dependent injury occurs following exposure to hemoglobin, a known nephrotoxin. Old mice (∼16 mo old), but not young mice (∼6 mo old), when administered hemoglobin, exhibited marked elevation in blood urea nitrogen (BUN) and serum creatinine, and acute tubular necrosis with prominent tubular cast formation. The aged kidney exhibited induction of heme oxygenase-1 (HO-1) and other genes/proteins that may protect against heme-mediated renal injury, including ferritin, ferroportin, haptoglobin, and hemopexin. Old mice did not evince induction of HO-2 mRNA by hemoglobin, whereas a modest induction of HO-2 mRNA was observed in young mice. To determine the functional significance of HO-2 in heme protein-induced AKI, we administered hemoglobin to relatively young HO-2+/+and HO-2−/−mice: HO-2−/−mice, compared with HO-2+/+mice, exhibited greater renal dysfunction and histologic injury when administered hemoglobin. In addition to failing to elicit a protective system such as HO-2 in response to hemoglobin, old mice exhibited an exaggerated maladaptive response typified by markedly greater induction of the nephrotoxic cytokine IL-6 (130-fold increase vs. 10-fold increase in mRNA in young mice). We conclude that aged mice, unlike relatively younger mice, are exquisitely sensitive to the nephrotoxicity of hemoglobin, an effect attended by a failure to induce HO-2 mRNA and a fulminant upregulation of IL-6. Age thus markedly augments the sensitivity of the kidney to heme proteins, and HO-2 confers resistance to such insults.

The diaphragm muscle (DIAm) is critically responsible for sustaining ventilation. Previously we showed in a commonly used model of spinal cord injury, unilateral spinal cord hemisection at C 2 (SH), that there are minimal changes to muscle fiber cross-sectional area (CSA) and fiber type distribution following 14 days of SH-induced ipsilateral DIAm inactivity. In the present study, effects of long-term SH-induced inactivity on DIAm fiber size and force were examined. We hypothesized that prolonged inactivity would not result in substantial DIAm atrophy or force loss. Adult rats were randomized to control or SH groups ( n = 34 total). Chronic bilateral DIAm electromyographic (EMG) activity was monitored during resting breathing. Minimal levels of spontaneous recovery of ipsilateral DIAm EMG activity were evident in 42% of SH rats (<25% of preinjury root mean square amplitude). Following 42 days of SH, DIAm specific force was reduced 39%. There was no difference in CSA for type I or IIa DIAm fibers in SH rats compared with age, weight-matched controls (classification based on myosin heavy chain isoform expression). Type IIx and/or IIb DIAm fibers displayed a modest 20% reduction in CSA ( P < 0.05). Overall, there were no differences in the distribution of fiber types or the contribution of each fiber type to the total DIAm CSA. These data indicate that reduced specific force following prolonged inactivity of the DIAm is associated with modest, fiber type selective adaptations in muscle fiber size and fiber type distribution.

Interventions that cultivate sustainable food systems to promote health, prevent obesity, and improve food security have the potential for many large-scale and long-lasting benefits including improvements in social, environmental, health, and economic outcomes. We briefly summarize findings from previous research examining associations between obesity and food insecurity and discuss the need for greater synergy between food insecurity initiatives and national obesity prevention public health goals in the United States. The common ground between these two nutrition-related public health issues is explored, and the transformation needed in research and advocacy communities around the shared goal of improving population health through individual, environmental, and policy level changes to promote healthy sustainable food systems is discussed. We propose an ecological framework to simultaneously consider food insecurity and obesity that identifies levers for change to promote sustainable food systems to improve food security and prevent obesity.

Thyroid disease is a common condition, and thyroid hormone excess or deficiency is known to have wide-ranging effects on a variety of organ systems. Our objective is to describe the magnitude, biochemical features, and clinical characteristics of hepatic abnormalities in patients with acute thyrotoxicosis. We performed a retrospective review of all patients admitted to our institution between January 1, 1998 and December 31, 2008 with a discharge diagnosis of acute thyrotoxicosis excluding iatrogenic causes. The records of these patients were reviewed and data extracted regarding demographic, biochemical, and clinical data particularly relevant to liver function. Fourteen patients were identified of which eleven had liver studies performed. The majority (90.9%) had Graves disease. Nine of eleven patients (81.8%) had some degree of hepatic abnormality. Seven patients (63.6%) had an elevation in one or both transaminases, and two (18.2%) had isolated synthetic dysfunction as manifested as an elevated INR and/or decreased albumin without transaminitis. The mean magnitude of deviation from the normal range was greater in the transaminases as compared to bilirubin, INR, or albumin. Definitive treatment was radioiodine ablation in six cases (54.5%) and surgical thyroidectomy in two cases (18.2%). Noniatrogenic acute thyrotoxicosis requiring hospitalization is a rare condition which is most frequently caused by Graves disease. The majority of patients have disordered liver tests of a highly variable nature, making the recognition of this association important in the care of patients presenting with acute thyrotoxicosis.

Lymphomatoid papulosis (LyP) and cutaneous anaplastic large cell lymphoma (ALCL) belong to the spectrum of cutaneous CD30+ lymphoproliferative disorders, an indolent form of T‐cell lymphoproliferative disease. We reviewed 21 cases of CD30+ lymphoproliferative lesions expressing cytotoxic profile (CD8+). Seven cases of cutaneous ALCL, 2 cases of systemic ALCL involving the skin, and 12 cases of LyP. The cases of LyP were predominated by small lymphocytes exhibiting a prominent epidermotropic pattern consistent with either type B or type D LyP. Four cases showed co‐expression of CD56. The ALCL cases included myxoid features, pseudoepitheliomatous change, and an intravascular component. In all cases that were primary in the skin an indolent clinical course was seen while one patient with systemic myxoid ALCL is in remission following systemic multiagent chemotherapy. The paucity of other neutrophils and eosinophils and concomitant granulomatous inflammation were distinctive features in cases of type B and type D LyP. CD30 and CD45 Ro positivity and a clinical course typical of LyP were useful differentiating features from an aggressive cytotoxic CD8+ T cell lymphoma. In all cases that were primary in the skin an indolent clinical course was observed. CD30 and CD45 Ro positivity and a clinical course typical of LyP were useful in preventing a misdiagnosis of an aggressive cytotoxic CD8+ T cell lymphoma.

AbstractThe brain operates through complex interactions in the flow of information and signal processing within neural networks. The ‘wiring’ of such networks, being neuronal or glial, can physically and/or functionally go rogue in various pathological states. Neuromodulation, as a multidisciplinary venture, attempts to correct such faulty nets. In this review, selected approaches and challenges in neuromodulation are discussed. The use of water‐dispersible carbon nanotubes has been proven effective in the modulation of neurite outgrowth in culture and in aiding regeneration after spinal cord injury in vivo. Studying neural circuits using computational biology and analytical engineering approaches brings to light geometrical mapping of dynamics within neural networks, much needed information for stimulation interventions in medical practice. Indeed, sophisticated desynchronization approaches used for brain stimulation have been successful in coaxing ‘misfiring’ neuronal circuits to resume productive firing patterns in various human disorders. Devices have been developed for the real‐time measurement of various neurotransmitters as well as electrical activity in the human brain during electrical deep brain stimulation. Such devices can establish the dynamics of electrochemical changes in the brain during stimulation. With increasing application of nanomaterials in devices for electrical and chemical recording and stimulating in the brain, the era of cellular, and even intracellular, precision neuromodulation will soon be upon us.

Low testosterone (T) levels in men have been shown to predict development of the metabolic syndrome, but the effects of T on lipid metabolism are incompletely understood. In a randomized, double-blind, placebo-controlled, crossover study, 12 healthy, young males received gonadotropin-releasing hormone agonist treatment 1 month prior to 3 of 4 trial days to induce castrate levels of T. On trial days, T gel was applied to the body containing either high or low physiological T dose or placebo. On the 4th trial day, participants constituted their own eugonadal controls. Each study comprised a 5-h basal period and a 3-h hyperinsulinemic-euglycemic clamp. Short-term hypogonadism did not affect VLDL triglyceride (TG) secretion, nor did it affect VLDL-TG concentrations. It was, however, characterized by lower total lipid oxidation. In addition, acute rescue with high physiological T increased VLDL-TG secretion during both basal and clamp conditions. These data show that T can act through fast nongenomic pathways in the liver. In addition, the early hypogonadal state is characterized by decreased total lipid oxidation, but whether these changes represent early hypogonadal metabolic dysfunction warrants further investigations. T is not a major determinant of resting VLDL-TG kinetics in men.

AbstractBackground and AimHamartomatous polyposis syndromes (HPS) are a group of rare inherited autosomal dominant disorders. Small bowel polyposis is one of the manifestations of HPS. Double‐balloon enteroscopy (DBE) with polypectomy may obviate repeated small bowel surgeries for polyp intussusception, obstruction, or bleeding. The efficacy and safety of DBE‐assisted polypectomy in HPS patients with clinically significant small bowel polyposis were evaluated.MethodsAll HPS patients who underwent DBE from January 2007 to April 2011 were identified using a prospectively maintained database. Data on patient demographics, pre‐DBE radiological studies, polyp characteristics, procedural outcomes, and complications were abstracted.ResultsTwenty‐two patients underwent a total of 34 DBE procedures. Pre‐DBE imaging included computed tomography enterography (n = 15), computed tomography enteroclysis (n = 5), small bowel follow‐through (n = 1), and magnetic resonance enterography (n = 1). Any small bowel polyp ≥ 1 cm in size on radiological imaging was referred for DBE‐assisted polypectomy. Antegrade and retrograde DBE were successful in reaching and resecting targeted polyps in 90% (18/20) and 71.4% (10/14) of procedures, respectively. The overall success rate for DBE‐assisted polypectomy was 82.3% (95% confidence interval: 66.5–91.6%). The median size of resected polyps was 2 cm (range 1–5 cm) and all were hamartomas. Minor adverse events occurred in four (11.8%) procedures, including abdominal pain (n = 2), immediate post‐polypectomy bleeding (n = 1), and self‐limited hematochezia (n = 1).ConclusionsDBE‐assisted polypectomy was successful in over 80% of HPS patients with an acceptable margin of safety. To the knowledge of the authors, this is one of the largest single‐center studies to report on the performance and safety of DBE‐assisted polypectomy in HPS patients.