Multimodal imaging in photic retinopathy

Letter to the Editor     

Compaction of Cohesive Granular Material: Application to Carbon Paste

Carbon-like materials such as the anode and the ramming paste play a crucial role in the efficiency of the Hall–Héroult process. The mechanical behavior of these materials during forming processes is complex and still ill-understood. This work aimed to investigate experimentally the mechanical behavior of a carbon paste used in the aluminum industry under different loading conditions. For this purpose, experiments consisting of (1) relaxation tests at different compaction levels, (2) quasi-static cyclic tests at several amplitudes, (3) monotonic compaction tests at varied strain rates, and (4) vibrocompaction tests at different frequencies were carried out. The obtained results highlight some fundamental aspects of the carbon paste behavior such as the strain rate’s effect on the paste compressibility, the hardening-softening behavior under cyclic loadings, the effect of cycling amplitude on the stress state and the paste densification, and the frequency effect on the vibrocompaction process. These results pave the way for the development of reliable rheological models for the modeling and the numerical simulation of carbon pastes forming processes.     

Association between the polymorphisms of IL-4 gene promoter (-590C>T), IL-13 coding region (R130Q) and IL-16 gene promoter (-295T>C) and allergic asthma

Allergic asthma is a multifactorial disease, influenced by genetic and environmental factors. Recent family-based studies have revealed evidence for linkage of human chromosomes 5q31-33, 12q15-24, 11q13 and 15q23.6 as regions likely to contain genes related to asthma. Among the candidate genes in these regions are the genes encoding for human interleukin-4, interleukin-13 and interleukin-16. To evaluate this linkage, we examined an Iranian population of patients with asthma. A total of 30 patients with allergic asthma and 50 normal subjects were studied. Allergic asthma was confirmed using skin prick test and spirometry. DNA was extracted from blood cells and IL-4 (-590C>T), IL-13 (R130Q) and IL-16 (-295T>C) polymorphisms were determined by PCR-RFLP method. Out of 30 patients with allergic asthma, the following genotypes for IL-4, IL-13 and IL-16 cytokines were found: IL-4 genotypes consisted of 17 (56.7%) CC, 8 (26.7%) CT and 5 (16.7%) TT; IL-13 genotypes consisted of 11 (36.7%) GG, 13 (43.3%) GA and 6 (20%) AA; IL-16 genotypes consisted of 23 (76.7%) TT and 7 (23.3%) CT. No patient showed CC genotype for IL-16. A higher proportion of case subjects with the C allele for the IL-4, G allele for the IL-13 and T allele for the IL-16 polymorphisms was found compared with the T, A and C alleles, respectively. These results suggest an influence of genetic variability at the promoter of IL-4 gene (-590C>T) and a coding region of IL-13 gene (R130Q) on the occurrence of allergic asthma and no relationship between IL-16 promoter polymorphism (-295T>C) and this disease.     

Insulin resistance in chronic hepatitis B and C.

AIM: To determine whether insulin resistance occurs in patients with chronic hepatitis B (CHB) and chronic hepatitis C (CHC) and its relationship with the presence of liver fibrosis and steatosis. METHODS: Untreated patients with CHC (n=60) or CHB (n=40), similar in age, gender, body mass index and waist-hip ratio, were studied. Relationship between anthropometric, biochemical (fasting serum insulin, C-peptide, ferritin, iron, TNF-alpha, cholesterol, triglyceride, bilirubin, hemoglobin and platelet concentrations) and liver biopsy (43 CHC and 20 CHB patients) findings was investigated by insulin resistance determined via the homeostasis model assessment (HOMA-IR). RESULTS: The mean fasting serum insulin was 14.9 (11.9) mU/mL in CHC and 21.4 (17.4) in the CHB group (normal range 0.7-9; p=0.049) and mean HOMA-IR was 3.1 (2.6) in CHC versus 4.7 (4.1) in the CHB group (normal range 0.12-4.61; p=0.036). HOMA-IR was significantly associated with fibrosis stage in the CHC group (p=0.015), but not in the CHB group. CONCLUSION: Hyperinsulinemia occurs in chronic viral hepatitis B and hepatitis C; insulin resistance is associated with stage of fibrosis in hepatitis C.     

A comparison between Goldmann applanation tonometry and dynamic contour tonometry after photorefractive keratectomy

Background

The intraocular pressure (IOP) could be measured by both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT). Although these two methods have been discussed widely after laser-assisted sub-epithelial keratectomy (LASIK), there is little data in the cases undergoing photorefractive keratectomy (PRK). We aimed to compare the changes of IOP measurements obtained by GAT and DCT after PRK for myopia/myopic astigmatism.

Methods

This prospective study enrolled 77 candidates (154 eyes) for PRK to correct myopia or myopic astigmatism and 30 matched patients (30 eyes) with myopia or myopic astigmatism who served as controls. Changes of the IOP measurements (ΔIOP) obtained by GAT and DCT before and at 6 months after PRK in the operated eyes, and at baseline and 6 months later in the controls, were documented. Changes of the central corneal thickness (ΔCCT) were determined in the same fashion.

Results

The mean IOP readings obtained by DCT were comparable before and at 6 months after procedure (18.34 ± 3.03 mmHg and 17.87 ± 2.61 mmHg respectively, p?=?0.41); whereas the mean IOP reading obtained by GAT decreased significantly 6 months postoperatively (17.92 ± 3.63 mmHg and 16.25 ± 2.66 mmHg, p?<?0.001). A significant correlation was present between the ΔIOP obtained by GAT and ΔCCT (r?=?0.61, p?<?0.001). Similar correlation was not significant between the DCT-obtained ΔIOP and the ΔCCT (r?=?0.07, p?=?0.44). The mean ΔIOP obtained by GAT was significantly higher in the operated eyes than in the controls (?1.54?±?1.45 vs 0.07?±?0.44 mmHg, p?=?0.02). The mean DCT-obtained ΔIOP was just marginally insignificant between the operated and nonoperated eyes (?0.63?±?0.59 vs 0.02?±?0.38 mmHg respectively; p?=?0.09).

Conclusions

The authors recommend DCT after PRK in the cases with myopia or myopic astigmatism     

Cytotoxic T-lymphocyte antigen 4 gene polymorphisms and susceptibility to chronic hepatitis B

AIM:To assess the three polymorphism regions withincytotoxic T-lymphocyte antigen 4(CTLA-4)gene,a C/Tbase exchange in the promoter region-318(CTLA-4-318C/T),an A/G substitution in the exon 1 position49(CTLA-4 49A/G),a T/C substitution in 1172(CTLA-4-1172T/C)in patients with chronic hepatitis B.METHODS:Fifty-one patients with chronic hepatitis Bvirus infection and 150 healthy subjects were recruitedsequentially as they presented to the hepatic clinic.Clas-sification of chronic hepatitis B virus(HBV)-infected pa-tients was as asymptomatic carrier state(26 patients)and chronic hepatitis B(25 patients).Genomic DNA wasisolated from anti-coagulated peripheral blood Buffy coatusing Miller's salting-out method.The presence of theCTLA-4 gene polymorphisms was determined using poly-merase chain reaction amplification refractory mutationsystem(ARMS).RESULTS:We observed a significant association be-tween-318 genotypes frequency(T C-,T C ,T-C )and susceptibility to chronic hepatitis B(P=0.012,OR=0.49,95%CI:0.206-1.162).However,we did notobserve a significant association for 49 genotype fre-quency(T C ,T C- T-C )and -1172 genotype fre-quency(C T ,T C- C T-)and state of disease.CONCLUSION:Our results suggest that CTLA-4 genepolymorphisms may partially be involved in the suscepti-bility to chronic hepatitis B.     

The Efficacy of an Herbal Medicine, Carmint, on the Relief of Abdominal Pain and Bloating in Patients with Irritable Bowel Syndrome: A Pilot Study

Carmint contains total extracts of Melissa officinalis, Mentha spicata, and Coriandrum sativum, which have antispasmodic, carminative, and sedative effects. As abdominal pain/discomfort and bloating are commonly observed in patients with irritable bowel syndrome, we decided to evaluate the effectiveness of Carmint in relieving these symptoms in irritable bowel syndrome patients. We randomly assigned 32 irritable bowel syndrome patients to receive either Carmint or placebo, plus Loperamide or psyllium (based on their predominant bowel function), for 8 weeks. T-test analysis of the results showed that the severity and frequency of abdominal pain/discomfort were significantly lower in the Carmint group than the placebo group at the end of the treatment (P=0.016 and P=0.001, respectively), as were the severity and frequency of bloating (P=0.02 and P=0.002, respectively). This pilot study suggests that Carmint plus loperamide or Carmint plus psyllium (depending on the irritable bowel syndrome subtype) might be effective in these patients.