Characterization of spatial performance in male and female Long-Evans rats by means of the Morris water task and the ziggurat task

Sex differences are prominent influences on spatial performance. One of the most common tasks to assess sex differences in spatial navigation in rodents is the Morris water task (MWT). In this task rats swim in a pool of water to locate a hidden platform employing the topographical relationships among the distal visual cues, pool wall, and goal location. Some evidence suggests that male rats display superior performance relative to females in the MWT. It is unknown, however, to what extent the sex difference in rats is task-dependent. This study compared the performance of male and female Long-Evans rats in the wet-land MWT versus the dry-land ziggurat task (ZT). The ZT represents a new dry-land task in which rats explore an arena with 16 ziggurat pyramids to locate food rewards. Several behavioural parameters, including latency, path length, path speed, probe trial performance, errors, and the number of returns were used as indices of spatial learning and memory. While males and females did not display significant differences in the traditional measures of spatial navigation within MWT, they displayed a robust sex difference in all measures of the ZT. These results indicate task-specific sex differences in spatial performance. Our findings suggest that males and females may employ different learning strategies in the MWT and ZT and that the latter task provides a more favourable task for assessing sex differences in rats.     

Comparison between Alpha and silver sulfadiazine ointments in treatment of Pseudomonas infections in 3rd degree burns

The goal of this study was to evaluate the efficacy of Alpha ointment in the treatment of burn wounds and compare its results with silver sulfadiazine (SS). Similar burn ulcers were produced on anterior surface of thigh of 60 rats. The wounds were infected with Pseudomonas aeruginosa and dressing and debridement was performed daily. The first group of rats received topical SS, the second group received Alpha ointment and the third (control group) received no medication. Wound healing, contraction, culture, and scar formation were evaluated at the end of the second and 10th week. Alpha ointment was equally effective as SS, considering wound healing and contraction. Wound infection was significantly less common in Alpha ointment group compared to the other two groups (p<0.05). Alpha ointment is a less expensive drug with an acceptable result compared to SS. Therefore, we recommend it as an alternative to SS, especially in patients with low economical backgrounds or in those who show adverse reactions to SS.     

Optimal β-blocker for prevention of atrial fibrillation after on-pump coronary artery bypass graft surgery: Carvedilol versus metoprolol

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass graft (CABG) surgery. It has been shown that prophylactic oral beta-blocker administration reduces the incidence of post-CABG AF. However, the optimal beta-blocker has not been identified. OBJECTIVE: This study sought to determine whether oral carvedilol (with its unique anti-inflammatory and antioxidant properties) is more effective than oral metoprolol for prevention of AF after CABG surgery. METHODS: Between April 2006 and December 2006, 120 patients (63 men, mean age 61 +/- 9.4 years) who were scheduled to undergo their first on-pump CABG were enrolled in this study. The patients were randomized in a prospective 1:1 manner to receive either oral carvedilol (n = 60) or oral metoprolol (n = 60). The end point of the study was the occurrence of the new-onset AF during the first 5 days after CABG. RESULTS: AF occurred in 29 of 120 patients (24.0%). The incidence of postoperative AF was 15.0% (9 of 60) in the carvedilol group and 33% (20 of 60) in the metoprolol group (P = .022). The carvedilol group was treated with mean daily dose of 46 +/- 9 mg and metoprolol group with mean daily dose of 93 +/- 11 mg. There were no differences between the study groups regarding any known preoperative, perioperative, or postoperative characteristics (all values were P >.05). No significant adverse effect was observed in either group. CONCLUSION: This prospective study suggested that oral carvedilol is more effective than oral metoprolol in the prevention of AF after on-pump CABG. It is well tolerated when started before and continued after the surgery. However, further prospective studies are needed to clarify this issue.     

Imaging of cervical spine trauma

The cervical spine, supporting such critical structures as the medulla, spinal cord, and cervical nerve roots, can be very challenging to image propertly because of its complex structural anatomy and superimposition of bony and soft tissue parts. In this article, the use and value of the various modalities that image the cervical spine are discussed. Plain radiography remains the best screening tool in the initial evaluation of the cervical spine after trauma. Additional views, such as swimmer's, pillar and lateral flexion, and extension, often are helpful in certain circumstances.     

Interferon-gamma gene polymorphism in Iranian patients with multiple sclerosis

Interferon- gamma (IFN- gamma) is an important immune regulator and inflammatory cytokine which is implicated in the pathogenesis of multiple sclerosis (MS). A single nucleotide polymorphism, T to A, at position +874 in the first intron has previously been shown. This polymorphism is associated with IFN- gamma production level. To study the effect of this polymorphism on susceptibility to multiple sclerosis, we screened genomic DNA samples from clinically definite MS patients and their unaffected first-degree relatives as controls, using sequence-specific primers (PCR-SSP). The results indicated that MS patients showed a lower TT (21.2% vs. 30.3%) and higher AA (21.2% vs. 12.1%) genotypes compared to controls, although there were statistically no differences in the IFN- gamma genotype distribution between these two groups. Thus, our data indicate that there is no association between IFN- gamma +874 polymorphism and MS susceptibility or severity of the disease.     

Impact of worsening renal function during hospital admission on resource utilization in patients with heart failure

Renal impairment frequently accompanies heart failure (HF) and is a recognized independent risk factor for morbidity and mortality. Few data are available assessing the impact of worsening renal function (WRF) during hospitalization on health care resource use in patients with HF. Health Insurance Portability and Accountability Act-compliant, de-identified, clinical, laboratory, and economic data for patients admitted to a tertiary care medical center with a primary diagnosis of HF were extracted by MedMining and reviewed retrospectively by the authors. Patients were excluded if they had no previous HF or were admitted for acute coronary syndrome or coronary artery bypass grafting within 30 days of index hospitalization. WRF was defined as ≥ 0.3 mg/dl increase in serum creatinine from baseline at any time during hospitalization. Of 5,803 hospitalized patients with primary HF diagnosis, 827 patients (14%) fulfilled all prespecified inclusion and exclusion criteria (74 ± 14 years of age, 43% men, 98% white, admission serum creatinine 1.4 ± 0.9 mg/dl, estimated glomerular filtration rate < 90 ml/min/1.73 m(2) at admission in 83%). During index hospitalization, WRF was identified in nearly 33%. Compared to patients without WRF, those with WRF had greater prevalence of diabetes (54% vs 43%), lower estimated glomerular filtration rate (44 ± 30 vs 62 ± 35 ml/min/1.73 m(2)), higher serum potassium (4.3 ± 0.7 vs 4.2 ± 0.7 mEq/L), and higher B-type natriuretic peptide (845 ± 821 vs 795 ± 947 pg/ml) at baseline (all p values < 0.05). Patients developing WRF incurred higher total inpatient costs ($10,977, range 671 to 212,819, vs $7,820, range 697 to 269,797, p < 0.001) and longer hospital stay (8.2 ± 6.8 vs 5.7 ± 5.5 days, p < 0.001). In conclusion, occurrence of WRF during HF-related hospitalization is associated with higher hospitalization costs and longer hospital stay.     

Relation of myocardial perfusion at rest and during pharmacologic stress to the PET patterns of tissue viability in patients with severe left ventricular dysfunction

Background. Stress perfusion imaging can assess effectively the amount of jeopardized myocardium, but its use for identifying underperfused but viable myocardium has yielded variable results. We evaluated the relation between measurements of myocardial perfusion at rest and during pharmacologic stress and the patterns of tissue viability as determined by positron emission tomographic (PET) imaging.Methods and Results. We studied 33 patients with coronary artery disease and left ventricular (LV) dysfunction (LV ejection fraction, 30% ± 8%). PET imaging was used to evaluate regional myocardial perfusion at rest and during pharmacologic stress with [¹³N]-ammonia as a flow tracer, and to delineate patterns of tissue viability (ie, perfusion-metabolism mismatch or match) using [¹⁸F]-deoxyglucose (FDG). We analyzed 429 myocardial regions, of which 229 were dysfunctional at rest. Of these, 30 had normal perfusion and 199 were hypoperfused. A severe resting defect (deficit>40% below normal) predicted lack of significant tissue viability; 31 of 35 regions (89%) had a PET match pattern denoting transmural fibrosis. Although regions with mild or moderate resting defects (deficit <40% below normal) showed evidence of metabolic activity, perfusion measurements alone failed to identify regions with PET mismatch (reflecting hibernating myocardium). Reversible stress defects were observed with slightly higher frequency in regions with a PET mismatch (10 of 37) than in those with a PET match (36 of 162) pattern of viability. A reversible stress defect was a specific (78%) marker, but was a relatively insensitive marker (27%) of viable myocardium as defined by the PET mismatch pattern.Conclusions. In patients with LV dysfunction, the severity of regional contractile abnormalities correlates with the severity of flow deficit at rest. Severe reductions in resting blood flow in these dysfunctional regions identify predominantly nonviable myocardium that is unlikely to have improved function after revascularization. Although dysfunctional myocardium with mild to moderate flow reductions contains variable amounts of viable tissue (as assessed by FDG uptake), flow measurements alone do not distinguish between regions with PET mismatch (potentially reversible dysfunction) and PET match (irreversible dysfunction). The presence of an irreversible defect on stress imaging is a relatively specific (78%) marker of PET match, whereas a reversible stress defect is a rather insensitive (27%) marker of viability, as defined by the PET mismatch pattern.     

Radiological features of Paget disease of bone associated with VCP myopathy

Objective  

Mutations in the Valosin-containing protein (VCP) gene cause a unique disorder characterized by classic Paget disease of bone (PDB), inclusion body myopathy, and frontotemporal dementia (IBMPFD). Our objective was to analyze the radiographic features of PDB associated with VCP mutations since there is a dearth of literature on the PDB component of VCP disease.