Fourier analysis of corneal Scheimpflug imaging: clinical use in keratoconus

AIM: To evaluate the clinical use of Fourier analysis of videokeratography data in the diagnosis and follow-up of keratoconus (KC). METHODS: We conducted a chart review of consecutive patients presented to our cornea clinic. A team of two experienced cornea specialists divided the patients into three groups: normal cornea, forme fruste KC (FFKC), and clinical KC. The exclusion criteria were a history of previous ocular surgery, any accompanying corneal pathology other than KC, high myopia (>6.00 diopters), amblyopia, pregnancy, breastfeeding, or any current autoimmune disease. The data of Fourier series harmonic analysis were evaluated for their diagnostic capacity using the receiver operating characteristic (ROC) curve. A binary logistic regression analysis was also conducted to construct a diagnostic model. A total of 259 eyes showed progression in the clinical KC group and underwent a combination of accelerated corneal collagen cross-linking and topography-guided customized treatment with an excimer laser. RESULTS: The study included 1262 eyes (618 normal, 530 KC, and 114 FFKC) of 1262 patients. We observed that maximum decentration (MaxDec) was almost as good as maximum keratometry (Kmax) in detecting progressive KC. The area under the curve (AUC) was 0.95 for KC [95% confidence interval (CI): 0.93-0.96] and 0.84 for FFKC (95%CI: 0.79-0.88). Higher predictive accuracy was obtained using a model combining the spherical component, MaxDec, irregularity, and regular astigmatism in the center of the cornea (AUC: 0.97; sensitivity: 89%, and specificity: 96%). CONCLUSION: Decentration, Kmax, and posterior radii of curvatures from a 3.0-mm optical zone centered on the thinnest point of the cornea provide the highest accuracy with low reproducibility of Kmax.     

Assessment of laminate technique using glass ionomer and resin composite for restoration of root filled teeth

Objective

To evaluate the open laminate technique using glass ionomer cements (GIC) in association with a low shrink composite for restoring root filled premolars.

Methods

Extensive MOD cavities plus endodontic access and root filling were performed in intact extracted maxillary premolars. Three restoration types were evaluated: (1) resin composite alone; (2) resin-modified GIC (RM-GIC) open laminate plus resin composite; (3) conventional GIC open laminate plus resin composite (n = 8 for all groups and tests). Three tests were conducted to assess restorations: (A) inward cusp deflection during light curing, using DCDTs; (B) fracture strength using a ramped oblique load at 45° to the long axis in a servohydraulic testing machine in comparison with intact and unrestored teeth; (C) proximal marginal leakage using methylene blue dye and the effect of thermocycling. Data were analysed using 1-way ANOVA for cuspal deflection and fracture strength and Fisher's exact test for leakage.

Results

Laminate restorations resulted in significantly less cuspal deflection compared with resin composite (4.2 ± 1.2 μm for RM-GIC and 5.1 ± 2.3 μm for conventional GIC vs. 12.2 ± 2.6 μm for composite, P < 0.001). Fracture strength was not significantly different among all groups. Failure with all restorations was predominantly adhesive at the tooth-restoration interface. The two laminate groups showed significantly better marginal seal than composite alone, but sealing ability of conventional GIC deteriorated after thermocycling.

Conclusions

Laminate restoration of root filled teeth had beneficial effects in terms of reducing cuspal deflection and marginal seal, with acceptable fracture strength.     

Rhino-orbito-cerebral mucormycosis during the COVID-19 third wave in 2021: an Egyptian preliminary report from a single tertiary hospital

Neurological Sciences - COVID-19 is a pandemic disease which predominantly affects the respiratory system with high critical care mortality and morbidity; however, it also causes multi-organ...     

Immunomodulatory effect of gelatin-coated silver nanoparticles in mice: Ultrastructural evaluation

Silver nanoparticles (SNP) are used in many pharmaceutical, cosmetic, and industrial products already available in the market. Although they are considered relatively safe, many toxic and pathological alterations in different organs including immune organs were reported after SNP administration. In this study, 10-week-old male mice (n = 20) were divided into two groups. Ten mice received greenly synthesized gelatin-coated silver nanoparticles in a dose of 10 mg/kg body weight for five consecutive days while the other 10 received 0.5 ml of distilled water daily for 5 days and kept as control. At the sixth day, all mice were sacrificed; blood and tissue samples were collected and prepared for pathological analysis. Liver and kidney lesions were in the form of degenerative and inflammatory changes. Interestingly, the immune organs were drastically affected by SNP treatment. Severe hyperplasia of the Peyer’s patches was noticed in the intestines of intoxicated animals both in gross and microscopic examination. Spleen was enlarged and showed large number of megakaryocytes. The particles were encountered in membrane-bound phagosomes inside macrophages in different organs like lungs and spleen. Blood picture complied to morphological findings with an increase in monocytes and eosinophils accompanied by drop in the platelets count in the intoxicated animals.     

Transgenic mice expressing human transferrin as a model for meningococcal infection

The pathogenesis of meningococcal disease is poorly understood due to the lack of a relevant animal model. Moreover, the use of animal models is not optimal as most meningococcal virulence determinants recognize receptors that are specifically expressed in human tissues. One major element of the host specificity is the system of meningococcal iron uptake by transferrin-binding proteins that bind specifically human transferrin but not murine transferrin. We developed a new mouse model for experimental meningococcal infection using transgenic mice expressing human transferrin. Intraperitoneal challenge of transgenic mice induced bacteremia for at least 48 h with an early stage of multiplication, whereas the initial inoculum was rapidly cleared from blood in wild-type mice. Inflammation in the subarachnoidal space with a high influx of polymorphonuclear cells was observed only in transgenic mice. Meningococcal mutants that were unable to use transferrin as a source of iron were rapidly cleared from both wild-type and transgenic mice. Thus, transgenic mice expressing human transferrin may represent an important advance as a new mouse model for in vivo studies of meningococcal virulence and immunogenicity factors.     

Das weltweite Medizinernetzwerk Aufklärung gegen Tabak – Ehrenamtliche Prävention made in Germany

Smoking is the leading preventable cause of premature death in Germany. The network “Education Against Tobacco” (EAT) is an initiative that was founded in Germany in 2012, in which more than 3500 medical students and physicians engage in volunteer work in about 80 medical faculties in 14 countries. In this article, the concept, activities, objectives and associated research studies oft he EAT initiative are introduced.On the school level, the initiative addresses 10- to 15-year-old secondary school students. In addition to a multimodal approach, school visits use modern media such as facemorphing apps, which are not only used by students (45,000 per year in 14 countries), but by a total of over 500,000 other people as well. The effectiveness of the school-based intervention is currently being investigated in randomised long-term studies with 20,000 adolescents in Germany. A first long-term study demonstrated evidence of a protective effect regarding the onset of smoking, especially among female students, students having a low level of education and students with a migratory background.The programme educates several hundred prospective physicians at 13 (of 28 participating) German medical faculties each year in science-based elective courses for the well-established smoking cessation counselling of patients and sensitises them to the tobacco epidemic. The approved members engage in dialogue with local members of the German house of representatives as “Ärzteverband Tabakprävention”.EAT motivates the prospective generation of physicians, initially through prevention in school settings, to face the challenge of national tobacco control at the university and federal level.     

Impact of occupational cadmium exposure on bone in sewage workers

Cadmium (Cd) is one of the environmental risk factors for bone loss. The present study included 40 sewage workers occupationally exposed to Cd. Forty nonexposed men were included as a control group. Current smokers represented 65% and 47.5% of the exposed and control groups, respectively.

The study aimed to investigate the hazard of occupational Cd exposure on bone health. This was achieved through measuring serum and urinary Cd, and calcium (Ca), in addition to serum osteoprotegerin (OPG) and estrogen receptor-α gene. Results showed significant elevation in serum Cd, OPG, and urinary Ca levels in the exposed compared to the controls. Bony aches and joint pain were more prevalent among the exposed workers. Serum and urinary Cd increased in exposed smokers relative to control smokers. Also, serum OPG levels showed significant rise among exposed smoker and nonsmoker compared to control smoker and nonsmoker groups. Serum Cd level increased significantly in PP and pp genotypes in exposed workers compared to controls, while elevated levels of serum OPG was observed in PP and Pp genotypes in exposed workers relative to controls.

Urinary Cd exhibited significant rise in both PP and pp genotypes in exposed workers, while Ca excretion was elevated in pp genotype only. The study reflected an association of genetic predisposition and Cd exposure in progression of osteoporosis. Further research is needed to explain the mechanisms of Cd impact on bone. The role of smoking is important and hence smoking cessation programs are essential for sewage workers.     

Effects of low and high doses of acetylsalicylic acid on penicillin-induced epileptiform activity

Background

The most common headache associated with epilepsy occurs after seizure activity and is called a postictal headache. Therefore, the objective of this study was to investigate the effects of low and high doses acetylsalicylic acid (aspirin) on a penicillin-induced experimental epilepsy model.

Synthesis of indole-2-hydrazones in search of potential leishmanicidal agents

Indole-2-hydrazones 3–30 were synthesized and evaluated for their antileishmanial activity. The compounds 24 (IC₅₀ = 1.86 ± 0.09 μM), 12 (IC₅₀ = 2.26 ± 0.16 μM), 23 (IC₅₀ = 3.81 ± 0.29 μM), 8 (IC₅₀ = 4.01 ± 0.32 μM), 17 (IC₅₀ = 4.89 ± 0.31 μM), 20 (IC₅₀ = 4.89 ± 0.26 μM), 3 (IC₅₀ = 5.12 ± 0.34 μM), 15 (IC₅₀ = 5.26 ± 0.26 μM), 6 (IC₅₀ = 6.16 ± 0.38 μM), and 21 (IC₅₀ = 6.18 ± 0.045 μM) showed better activities than standard pentamidine (IC₅₀ = 7.02 ± 0. 09 μM). Compounds 4, 5, 7, 9–11, 13, 16, 18, 19, 22, 25–28, and 30 displayed good activities. The compounds 14 and 29 were found to be inactive. The synthesized compounds were characterized by different spectroscopic techniques.