A comparison of 8 and 16 frames gated SPECT imaging for determination of left ventricular volumes and ejection fraction: effects of gender and myocardial counts

The International Journal of Cardiovascular Imaging - In myocardial gated SPECT imaging each cardiac cycle is divided into 8 or 16 temporal frames and the cause of the difference between 8 and 16...     

Reversible cerebral vasoconstriction syndrome (RCVS): an interesting case report

BackgroundReversible Cerebral Vasoconstriction Syndrome is a condition of transient cerebral vascular spasms, which usually presents with recurrent thunderclap headaches and recovers within 3 months. Several probable triggers and underlying factors, such as sex hormones, vasoactive drugs, head trauma or surgery, and tumors, have been implicated.Case presentationIn this paper, we present a 53-year-old woman with thunderclap headaches and normal lab tests who was radio-clinically diagnosed with reversible cerebral vasoconstriction syndrome and treated accordingly. Then, she experienced the recurrence of RCVS after about 2 years and headaches after 1 year in association with high blood pressure, high blood sugar, hypothyroidism, hyperlipidemia, and a urine metanephrine level of 5 times higher than the normal limit, suggesting a diagnosis of pheochromocytoma. After confirmation of the diagnosis with further imaging studies, surgical removal of the tumor resolved all the signs and symptoms.ConclusionOften underdiagnosed, pheochromocytoma could be an important condition associated with RCVS. It is important for clinicians to bear this diagnosis in mind while dealing with similar cases of recurrent thunderclap headaches.     

The effects of diode laser (660 nm) on the rate of tooth movements: an animal study

Lasers in Medical Science - Low-level laser has been indicated to have the capability to facilitate the differentiation of the osteoclastic and osteoblastic cells which are responsible for the bone...     

Correlation between expression of MMP-9 and MMP-3 in Helicobacter pylori infected patients with different gastroduodenal diseases

Background and study aims

Helicobacter pylori (H. pylori) has been implicated in the pathogenesis of most important gastro-duodenal diseases, such as gastritis, peptic ulcer disease (PUD) and gastric cancer. H. pylori upregulates the expression and activity of several matrix metalloproteinases (MMPs) in the gastric mucosa, but the role of MMP-3 and MMP-9 in infected patients with H. pylori have not been clearly defined yet. We examined mucosal MMP-3 and MMP-9 mRNA levels in gastric mucosa of H. pylori infected patients and evaluated the effects of virulence factors cagA and vacA allelic variants on these levels. We also determined correlation between mucosal MMP-3 and MMP-9 mRNA levels and types of disease.

Lack of Association Between Transforming Growth Factor Beta 1 -509C/T and +915G/C Polymorphisms and Chronic Hepatitis B in Iranian Patients

Background:

Chronic hepatitis B is one of the world''s major health concern. The etiological agent of this infection is hepatitis B virus (HBV), which can evade the immune system response. Transforming growth factor beta 1 (TGF-β1) can act against HBV by suppressing the viral replication. The TGF-β1 also plays an important role in preventing liver damage in chronically HBV infected patients.

Objectives:

In this study, the association of TGF-β1 +915G/C and -509C/T gene polymorphisms with chronic hepatitis B was evaluated in Iranian patients.

Materials and Methods:

A population-based case–control study was conducted in Taleghani Hospital, Tehran. A number of 220 patients with chronic hepatitis B and the same number of healthy control subjects were designated the case and the control groups. The PCR-Restriction Fragment Length Polymorphism Method (PCR-RFLP) method was used for genotyping both polymorphisms. Ten percent of the control samples were sequenced to confirm the results.

Results:

No statically significant differences in genotype distribution and allele frequency were observed for both polymorphisms between healthy controls and patients with chronic hepatitis B.

Conclusions:

There was no association between TGF-β1 -509C/T and +915G/C polymorphisms with chronic hepatitis B and it seems that these changes don not play a significant role in increasing the risk of chronic infection in Iranian patients.     

The Therapeutic Use of Analgesics in Patients With Liver Cirrhosis: A Literature Review and Evidence-Based Recommendations

Context:

Pain management in cirrhotic patients is a major clinical challenge for medical professionals. Unfortunately there are no concrete guidelines available regarding the administration of analgesics in patients with liver cirrhosis. In this review we aimed to summarize the available literature and suggest appropriate evidence-based recommendations regarding to administration of these drugs.

Evidence Acquisition:

An indexed MEDLINE search was conducted in July 2014, using keywords “analgesics”, “hepatic impairment”, “cirrhosis”, “acetaminophen or paracetamol”, “NSAIDs or nonsteroidal anti-inflammatory drugs”, “opioid” for the period of 2004 to 2014. All randomized clinical trials, case series, case report and meta-analysis studies with the above mentioned contents were included in review process. In addition, unpublished information from the Food and Drug Administration are included as well.

Results:

Paracetamol is safe in patients with chronic liver disease but a reduced dose of 2-3 g/d is recommended for long-term use. Non-steroidal anti-inflammatory drugs (NSAIDs) are best avoided because of risk of renal impairment, hepatorenal syndrome, and gastrointestinal hemorrhage. Most opioids can have deleterious effects in patients with cirrhosis. They have an increased risk of toxicity and hepatic encephalopathy. They should be administrated with lower and less frequent dosing in these patients and be avoided in patients with a history of encephalopathy or addiction to any substance.

Conclusions:

No evidence-based guidelines exist on the use of analgesics in patients with liver disease and cirrhosis. As a result pain management in these patients generates considerable misconception among health care professionals, leading under-treatment of pain in this population. Providing concrete guidelines toward the administration of these agents will lead to more efficient and safer pain management in this setting.     

Detection of vertical root fractures using digitally enhanced images: reverse‐contrast and colorization

Abstract – Root fracture diagnosis is a clinical difficulty that in most cases can only be detected through radiography. The objective of this study was to compare the diagnostic accuracy of two types of digitally enhanced images (reverse‐contrast and colorization) with original digital radiographies in detecting experimental root fractures. Two hundred extracted single‐rooted human teeth were endodontically instrumented and then divided in two groups, one control group and one test group, including fractured teeth. Vertical root fractures were experimentally made in the fractured group. The digital image of each tooth was taken, using the paralleling technique. There were three groups of images: (i) original, (ii) reverse contrast, and (iii) colorized. Three experienced dental specialists examined the images with no prior knowledge of the distribution of the root fractures. Two‐way analysis of variance was used to assess the differences in accuracy, sensitivity, and specificity of each technique in detecting root fractures. Cohen’s kappa coefficients were calculated to investigate the degree of interobserver agreement. The accuracy, sensitivity, and specificity of original images were 67.4%, 66.7%, and 68%, respectively; these amounts were 61.5%, 61%, and 65.5% in reverse contrast images and 66.4%, 70.7%, and 62% in colorized digital radiography. The original images had the best inter observer kappa coefficients (between 0.45 and 0.55). The results showed that the accuracy of original images is better than reverse contrast and colorized images. Use of reverse‐contrast and colorization digital images in root fracture detection should be regarded as an adjunct to other diagnostic methods not as a highly critical diagnostic aid.     

The Impact of Preload Alteration on the Myocardial Performance Index through Implementing Positive End Expiratory Pressure

Load independent methods should be used for the assessment of ventricular function. Debate still exists regarding whether tissue Doppler imaging (TDI) indices are influenced by preload. Here, we evaluated the effect of positive end expiratory pressure (PEEP) related preload reduction on both conventional pulsed Doppler (PD) and TDI myocardial performance index (MPI). Thirty-eight mechanically ventilated patients of 3 months to 12 years old (mean ± SD age of 30 ± 11months) without overt heart disease were enrolled. Doppler mitral inflow velocities, isovolumetric contraction and relaxation times and aortic ejection time in addition to TDI peak systolic, early and late diastolic velocities from the basal segment of left ventricular lateral wall were determined for each patient before and after applying high PEEP (10 cmH(2) O).PD-MPI was load dependent (0.61 ± 0.22 vs. 0.78 ± 0.25, P = 0.002). However, TDI-MPI did not significantly change after the use of high PEEP declining the left ventricular volume loading (0.78 ± 0.21 vs. 0.84 ± 0.22, P = 0.23). Hence, regarding various interfering pathophysiologic factors particularly preload reduction, it seems that TDI-MPI would be a more reliable index for the assessment of ventricular function.     

Bio-inspired stable antimicrobial peptide coatings for dental applications

We developed a novel titanium coating that has applications for preventing infection-related implant failures in dentistry and orthopedics. The coating incorporates an antimicrobial peptide, GL13K, derived from parotid secretory protein, which has been previously shown to be bactericidal and bacteriostatic in solution. We characterized the resulting physicochemical properties, resistance to degradation, activity against Porphyromonas gingivalis and in vitro cytocompatibility. Porphyromonas gingivalis is a pathogen associated with dental peri-implantitis, an inflammatory response to bacteria resulting in bone loss and implant failure. Our surface modifications obtained a homogeneous, highly hydrophobic and strongly anchored GL13K coating that was resistant to mechanical, thermochemical and enzymatic degradation. The GL13K coatings had a bactericidal effect and thus significantly reduced the number of viable bacteria compared to control surfaces. Finally, adequate proliferation of osteoblasts and human gingival fibroblasts demonstrated the GL13K coating’s cytocompatibility. The robustness, antimicrobial activity and cytocompatibility of GL13K-biofunctionalized titanium make it a promising candidate for sustained inhibition of bacterial biofilm growth. This surface chemistry provides a basis for development of multifunctional bioactive surfaces to reduce patient morbidities and improve long-term clinical efficacy of metallic dental and orthopedic implants.