Mice lacking ghrelin receptors resist the development of diet-induced obesity

Ghrelin is the endogenous ligand for the growth hormone secretagogue receptor (GHSR; ghrelin receptor). Since its discovery, accumulating evidence has suggested that ghrelin may play a role in signaling and reversing states of energy insufficiency. For example, ghrelin levels rise following food deprivation, and ghrelin administration stimulates feeding and increases body weight and adiposity. However, recent loss-of-function studies have raised questions regarding the physiological significance of ghrelin in regulating these processes. Here, we present results of a study using a novel GHSR-null mouse model, in which ghrelin administration fails to acutely stimulate food intake or activate arcuate nucleus neurons. We show that when fed a high-fat diet, both female and male GHSR-null mice eat less food, store less of their consumed calories, preferentially utilize fat as an energy substrate, and accumulate less body weight and adiposity than control mice. Similar effects on body weight and adiposity were also observed in female, but not male, GHSR-null mice fed standard chow. GHSR deletion also affected locomotor activity and levels of glycemia. These findings support the hypothesis that ghrelin-responsive pathways are an important component of coordinated body weight control. Moreover, our data suggest that ghrelin signaling is required for development of the full phenotype of diet-induced obesity.     

PillCam ESO in esophageal studies: improved diagnostic yield of 14 frames per second (fps) compared with 4 fps

BACKGROUND AND STUDY AIM: Capsule endoscopy, using the PillCam ESO and sending images at a rate of 4 frames per second (fps), has a high sensitivity and specificity in diagnosing gastroesophageal reflux disease (GERD) lesions. We tested a new device which produces images at a rate of 14 fps. The diagnostic performance and esophageal visualization of these two devices were compared. PATIENTS AND METHODS: 42 patients with GERD symptoms and eight patients with a history of Barrett's esophagus had an esophagogastroduodenoscopy (EGD). All patients underwent capsule endoscopy of the esophagus within 1 hour prior to EGD. The first 25 patients had a capsule endoscopy examination with the 4-fps device. The following 25 patients underwent capsule endoscopy under identical conditions but using the 14-fps device. The reader of the capsule endoscopy study was blinded to the EGD findings. A diagnosis of GERD or Barrett's esophagus was established with EGD. The findings at capsule endoscopy were compared with the EGD findings. We also examined how frequently the esophagus in its entirety was visualized by these two devices. RESULTS: The 4-fps device diagnosed 16/19 cases of esophageal erosions or ulcers (sensitivity 84 %) and 6/8 cases of Barrett's esophagus (sensitivity 75 %). The 14-fps capsule diagnosed 16/16 cases of esophageal ulcers or erosions and 7/7 cases of Barrett's esophagus (sensitivity 100 %). The total diagnostic miss rate in the 4-fps group was 5/27 (18 %) whereas the diagnostic miss rate in the 14-fps group was 0/23 (0 %) P < 0.02). The upper esophageal sphincter (UES) was clearly identified in 6/25 patients (24 %) in the 4-fps group and in 20/25 patients (80 %) in the 14-fps group ( P < 0.01). The entire esophagus was well visualized in 3/25 patients (12 %) by the 4-fps device and in 19/25 (76 %) by the 14-fps device ( P < 0.01). The superiority of the 14-fps PillCam ESO capsule is consistent with the data obtained from fluoroscopic studies of swallowed PillCam capsules, showing that capsule speed may reach 20 cm/s. For the 14-fps PillCam this means one image transmitted per 3-cm segment at maximal capsule speed, therefore still allowing for full visualization of the entire esophagus. CONCLUSIONS: Capsule endoscopy using the 14-fps PillCam ESO showed a greater sensitivity than that of the 4-fps device for identifying GERD. The 14-fps PillCam ESO was statistically superior to the 4-fps device in visualizing the opening of the UES and the entirety of the esophagus.     

"Hemicrania Continua": A Clinical Review

Hemicrania continua (HC) is a headache entity completely responsive to indomethacin. Since 1984, 18 cases have been described, 15 females and 3 males, i.e. a F:M ratio of 5.0. The finding of a female preponderance, like that in chronic paroxysmal hemicrania, is a new observation. HC is, in general, a unilateral headache in the sense that it sets in on one side and subsequently sticks to this side. In two cases, both sides might possibly be involved, when the pain was at its maximum. In another (somewhat dubious) case the headache was bilateral. The pain was continuous from the beginning in 8 of 18 cases (early stage ratio continuous: non-continuous = 0.8). Over time, the headache developed a continuous character in 16 of the 18 cases, producing a "continuous: non-continuous ratio" of 8:1. The intensity of pain generally was moderate and was not reported as excruciatingly severe by any patient. The autonomic involvement from a clinical point of view, was clearly less pronounced than that of other unilateral headaches, such as cluster headache and chronic paroxysmal hemicrania.     

Statins and Voriconazole Induce Programmed Cell Death in Acanthamoeba castellanii

Members of the genus Acanthamoeba are facultative pathogens of humans, causing a sight-threatening keratitis and a life-threatening encephalitis. In order to treat those infections properly, it is necessary to target the treatment not only to the trophozoite but also to the cyst. Furthermore, it may be advantageous to avoid parasite killing by necrosis, which may induce local inflammation. We must also avoid toxicity of host tissue. Many drugs which target eukaryotes are known to induce programmed cell death (PCD), but this process is poorly characterized in Acanthamoeba. Here, we study the processes of programmed cell death in Acanthamoeba, induced by several drugs, such as statins and voriconazole. We tested atorvastatin, fluvastatin, simvastatin, and voriconazole at the 50% inhibitory concentrations (IC₅₀s) and IC₉₀s that we have previously established. In order to evaluate this phenomenon, we investigated the DNA fragmentation, one of the main characteristics of PCD, with quantitative and qualitative techniques. Also, the changes related to phosphatidylserine exposure on the external cell membrane and cell permeability were studied. Finally, because caspases are key to PCD pathways, caspase activity was evaluated in Acanthamoeba. All the drugs assayed in this study induced PCD in Acanthamoeba. To the best of our knowledge, this is the first study where PCD induced by drugs is described quantitatively and qualitatively in Acanthamoeba.     

Toxicity of Amphotericin B Deoxycholate-Based Induction Therapy in Patients with HIV-Associated Cryptococcal Meningitis

Amphotericin B deoxycholate (AmBd) is the recommended induction treatment for HIV-associated cryptococcal meningitis (CM). Its use is hampered by toxicities that include electrolyte abnormalities, nephrotoxicity, and anemia. Protocols to minimize toxicity are applied inconsistently. In a clinical trial cohort of AmBd-based CM induction treatment, a standardized protocol of preemptive hydration and electrolyte supplementation was applied. Changes in blood counts, electrolyte levels, and creatinine levels over 14 days were analyzed in relation to the AmBd dose, treatment duration (short course of 5 to 7 days or standard course of 14 days), addition of flucytosine (5FC), and outcome. In the 368 patients studied, the hemoglobin levels dropped by a mean of 1.5 g/dl (95% confidence interval [CI], 1.0 to 1.9 g/dl) following 7 days of AmBd and by a mean of 2.3 g/dl (95% CI, 1.1 to 3.6 g/dl) after 14 days. Serum creatinine levels increased by 37 μmol/liter (95% CI, 30 to 45 μmol/liter) by day 7 and by 49 μmol/liter (95% CI, 35 to 64μmol/liter) by day 14 of AmBd treatment. Overall, 33% of patients developed grade III/IV anemia, 5.6% developed grade III hypokalemia, 9.5% had creatinine levels that exceeded 220 μmol, and 6% discontinued AmBd prematurely. The addition of 5FC was associated with a slight increase in anemia but not neutropenia. Laboratory abnormalities stabilized or reversed during the second week in patients on short-course induction. Grade III/IV anemia (adjusted odds ratio [aOR], 2.2; 95% CI, 1.1 to 4.3; P = 0.028) and nephrotoxicity (aOR, 4.5; 95% CI, 1.8 to 11; P = 0.001) were risk factors for 10-week mortality. In summary, routine intravenous saline hydration and preemptive electrolyte replacement during AmBd-based induction regimens for HIV-associated CM minimized the incidence of hypokalemia and nephrotoxicity. Anemia remained a concerning adverse effect. The addition of flucytosine was not associated with increased neutropenia. Shorter AmBd courses were less toxic, with rapid reversibility.