Densitometry Measurements Research Articles

Corneal densitometry measurements comparison between anterior segment OCT and scheimpflug imaging

PurposeTo evaluate and compare the repeatability of corneal densitometry (CD) measurements obtained using both an anterior-segment optical coherence tomography (AS-OCT) device and a Scheimpflug camera system, while also assessing the level of agreement. The study also sought to investigate the correlation of CD with age, gender, and central corneal thickness (CCT) in normal eyes.MethodsCD measurements were obtained using the Casia 2 and the Pentacam AXL Wave. Data were collected on Total Corneal Densitometry and 4 concentric corneal annular areas, these are referred to as zone 1, denoting the central area, through to zone 4, designating the outermost peripheral region. Repeatability was assessed using intra-session test–retest variability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC). The agreement was evaluated using Bland–Altman plots. Correlation analysis was performed between CD, age, gender, and CCT.ResultsThe study included 96 healthy volunteers. The Casia 2 demonstrated high repeatability with ICC values exceeding 0.9 in all the corneal zones and lower CoV values compared to the Pentacam AXL Wave (ranging from 1.07% to 2.25% for Casia 2 and from 1.91% to 6.89% for Pentacam).95% LoA were within ± 2 standard deviation from the average mean except from zone 1 (± 2.42).However, the measurements showed a consistent bias among all the corneal zones. CD values were positively correlated with age, except for zone 1 with the Pentacam (p = 0.083).ConclusionsThe findings suggest that the Casia 2 can be a reliable tool for assessing corneal transparency in healthy individuals, however its measurements are not interchangeable with those provided by the Pentacam. The AS-OCT device may be more sensitive in detecting subtle age-related changes in CD within the central zone.

Corneal stromal changes following simple limbal epithelial transplantation on Scheimpflug densitometry: Early results.

Chemical injury to eyes causes limbal stem cell deficiency (LSCD), which leads to conjunctival epithelium and underlying stromal changes. Simple limbal epithelial transplant helps to restore corneal epithelium and corneal stromal clarity. These changes are documented in this prospective eye study. To report the changes in epithelial/stromal (E/S) reflectivity ratio and corneal stromal densitometry following simple limbal epithelial transplantation (SLET) in patients with unilateral chemical burn-induced LSCD. It is a prospective imaging study of cornea before and after SLET. Corneal densitometry with Pentacam and epithelial and stromal reflectivity on anterior segment optical coherence tomography were analyzed for five patients (n = 5 eyes), who underwent autologous SLET for unilateral chemical burn-induced LSCD. Mann-Whitney U-test and Pearson correlation. A significant improvement in E/S reflectivity was noted at 1 month (P < 0.05) after SLET, and this was maintained until the end of 6 months. The densitometry measurements decreased in the entire cornea at every level, that is, anterior, central, and posterior cornea. However, the values did not normalize till the last follow-up at 6 months. A trend of normal corneal epithelization exists in eyes undergoing SLET. Densitometry at all the levels, the anterior, central, and posterior cornea, also decreases after SLET. SLET improves visual outcomes in LSCD eyes not only by epithelization but also by reducing stromal scarring.

Comparison of Scheimpflug Imaging (Pentacam HR) and Swept-Source Optical Coherence Tomography (CASIA2) in Eyes With Macular Corneal Dystrophy.

Assessment of tomographic characteristics and interdevice comparability between Scheimpflug imaging (Pentacam HR, Oculus Optikgeräte GmbH, Wetzlar, Germany) and swept-source optical coherence tomography (CASIA2, Tomey Corp., Nagoya, Japan) in eyes with macular corneal dystrophy (MCD). Eyes with MCD were examined by Pentacam HR and CASIA2. Interdevice comparison was performed using a Wilcoxon matched pairs test and Bland-Altman plots with 95% limit of agreement. A Spearman rank correlation coefficient was used for correlating indices of both devices. This retrospective study included 31 eyes of 18 patients (mean age: 32.1 ± 10.7 years). Eyes with MCD demonstrated a moderate astigmatism with a Cylinder anterior of 2.56 ± 1.50 D (Pentacam HR) and 2.52 ± 1.57 D (CASIA2) without a difference between both devices. CASIA2 (0.34 ± 0.14 D) measured lower values of Cylinder posterior compared with Pentacam HR (0.96 ± 0.66 D) (P < 0.0001). Comparison of pachymetry (Pentacam HR vs. CASIA2) showed higher values of the central corneal thickness (619 ± 227 μm vs. 445 ± 67 μm, P = 0.0001) and the thinnest corneal thickness (499 ± 165 μm vs. 430 ± 60 μm, P = 0.0167) for Pentacam HR. Corneal densitometry measurement revealed that increasing gray scale units caused a greater interdevice difference for pachymetry values, as Pentacam HR measured higher than CASIA2 for more opaque corneas. Eyes with MCD tend to have thinner corneas and a higher amount of corneal astigmatism than healthy eyes. In advanced MCD, Scheimpflug technology may mistakenly overestimate corneal thickness. The pachymetry measurement of the optical coherence tomography should be used when planning corneal surgery such as excimer laser-assisted phototherapeutic keratectomy to determine the ablation depth.

Bone mineral density in patients with Cushing’s syndrome

Objective: Cushing’s syndrome is caused by the excessive secretion of cortisol or the intake of exogenous cortisol. Morbidity caused by osteoporosis is a major complication that cannot be ignored. We conducted a study to evaluate bone density and fracture risk factors in patients with Cushing’s syndrome. Patients and Methods: This retrospective case-control study involved 176 patients diagnosed with Cushing’s syndrome [153 female and 34 male patients] and 84 controls [72 female and 12 male patients]. Patients admitted to the clinics within the last eight years were included in the analysis. We collected demographic, clinic laboratory data, and bone densitometry measurements from electronic patient files. The classification of patients into normal, osteopenia, or osteoporosis groups is determined by their Body Mineral Density measurements based on the World Health Organization criteria. Results: Among the patients, 135 were diagnosed with Cushing’s disease and 41 with adrenal adenomas. Patients with Cushing’ syndrome showed a higher incidence of osteopenia (11.4%) and osteoporosis (2.8%) when compared to the control group. No osteoporosis cases were found in the control group, while nine cases of osteopenia were detected. Osteopenia was significantly more common in adrenal adenoma patients than in those with pituitary Cushing’s disease. Osteopenia was present in 39.1% of adrenal Cushing’s patients, with only 8.7% (n = 2) having osteoporosis. Osteopenia was observed in 11 patients (23.4%) with pituitary Cushing’s disease, while only 4 patients (8.5%) had osteoporosis. Conclusions: Osteopenia is more prevalent in patients with adrenal Cushing’s syndrome.

Functional and morphological evaluation of the dentofacial system in patients with distal occlusion using ultrasonic diagnostic methods

Relevance. The integrity of the dentofacial system, significantly influenced by the functional condition of the masseter muscles (MM) and the morphological alterations in the alveolar bone, plays a crucial role in the outcome and duration of orthodontic treatment for distal occlusion. Ultrasonic diagnostic methods, due to their physiological compatibility, high information content, and ergonomic design, offer a preferable alternative for assessing and tracking these changes throughout orthodontic treatment.Materials and methods. This study included 55 individuals of both genders, aged 9-12, with either normal occlusions (NO) or distal occlusions (DO). Ultrasound examinations of the MM at rest and during maximum voluntary teeth clenching were conducted to evaluate MM thickness and echotexture. Ultrasonic densitometry measurements were conducted through the assessment of ultrasound transit velocity (UTV). This was carried out across the interalveolar bone with probes positioned on the buccal and oral sides between two neighboring teeth roots.Results. The findings indicated that DO patients had a notably thicker MM compared to their NO counterparts. Variations in MM echotexture were observed, with differences in the anechogenic and hyper echogenic zones. Recorded UTV values illustrated that the highest alveolar bone density in DO subjects was predominantly in the frontal regions of both jaws on the left side, whereas the lowest density was observed in the right lateral regions. For NO subjects, the highest density values were identified in the frontal region of the mandibular bone, with the lowest in the maxillary bone's lateral regions on both sides.Conclusion. The application of advanced ultrasonic diagnostic methods in this study facilitated a detailed functional and morphological analysis of the MM, as well as an evaluation of alveolar bone density in individuals with both distal and normal occlusions. The development of ultrasonic alveolar bone density chart from this research provides a valuable addition to dental examination protocols for patients undergoing orthodontic treatment.

Evaluation of corneal densitometry values with Pentacam in cases of ocular hypertension and pseudoexfoliative glaucoma

BackgroundExamination of corneal densitometry measurements using the Pentacam Scheimpflug imaging system in cases of pseudoexfoliative glaucoma (PEXG) and ocular hypertension (OHT). MethodsThe study included 50 eyes of 29 PEXG patients, 25 eyes of 16 OHT patients, and 76 eyes of 38 healthy control subjects followed in the glaucoma clinic. Corneal densitometry values of all cases were measured using the Scheimpflug imaging system (Pentacam, Oculus, Germany). Corneal densitometry was assessed based on 4 concentric radial zones (0–2 mm, 2–6 mm, 6–10 mm, and 10–12 mm) and depths (anterior, central, posterior, and total) within the Scheimpflug imaging system. The results were statistically analyzed. ResultsCorneal densitometry values examined between the OHT and control groups were higher in OHT and statistically significant (p < 0.05). Corneal densitometry values examined between the PEXG and control groups were higher in PEXG and statistically significant (p < 0.05). In comparison between the PEXG and OHT groups, corneal densitometry values in the central 0–2 mm, 2–6 mm, and 6–10 mm; posterior 0–2 mm and 2–6 mm radial zones were higher in PEXG and statistically significant (p < 0.05). ConclusionsIt was observed that elevated intraocular pressure levels in OHT cases could lead to changes in the cornea, consequently increasing corneal densitometry values. The higher corneal densitometry values in PEXG cases compared to OHT were attributed to the accumulation of pseudoexfoliative material in the cornea. Based on our study, corneal densitometry could serve as a potential biomarker for early glaucoma detection in OHT cases and could be employed to assess corneal transparency during the follow-up of PEXG cases.

A high throughput immuno-affinity mass spectrometry method for detection and quantitation of SARS-CoV-2 nucleoprotein in human saliva and its comparison with RT-PCR, RT-LAMP, and lateral flow rapid antigen test.

Many reverse transcription polymerase chain reaction (RT-PCR) methods exist that can detect SARS-CoV-2 RNA in different matrices. RT-PCR is highly sensitive, although viral RNA may be detected long after active infection has taken place. SARS-CoV-2 proteins have shorter detection windows hence their detection might be more meaningful. Given salivary droplets represent a main source of transmission, we explored the detection of viral RNA and protein using four different detection platforms including SISCAPA peptide immunoaffinity liquid chromatography-mass spectrometry (SISCAPA-LC-MS) using polyclonal capture antibodies. The SISCAPA-LC MS method was compared to RT-PCR, RT-loop-mediated isothermal amplification (RT-LAMP), and a lateral flow rapid antigen test (RAT) for the detection of virus material in the drool saliva of 102 patients hospitalised after infection with SARS-CoV-2. Cycle thresholds (Ct) of RT-PCR (E gene) were compared to RT-LAMP time-to-positive (TTP) (NE and Orf1a genes), RAT optical densitometry measurements (test line/control line ratio) and to SISCAPA-LC-MS for measurements of viral protein. SISCAPA-LC-MS showed low sensitivity (37.7 %) but high specificity (89.8 %). RAT showed lower sensitivity (24.5 %) and high specificity (100 %). RT-LAMP had high sensitivity (83.0 %) and specificity (100.0 %). At high initial viral RNA loads (<20 Ct), results obtained using SISCAPA-LC-MS correlated with RT-PCR (R2 0.57, p-value 0.002). Detection of SARS-CoV-2 nucleoprotein in saliva was less frequent than the detection of viral RNA. The SISCAPA-LC-MS method allowed processing of multiple samples in <150 min and was scalable, enabling high throughput.

Differences in the Quantitative HRCT Characteristics of Patients with Asthma, COPD and Asthma-COPD Overlap and Their Relationships with Pulmonary Function.

We compared pulmonary function indices and quantitative CT parameters of airway remodeling, air trapping, and emphysema in asthmatic patients and patients with COPD and asthma-COPD overlap (ACO) and explored their relationships with airflow limitation. Patients with asthma (n=48), COPD (n=52), and ACO (n=30) and controls (n=54) who completed pulmonary function tests and HRCT scans were retrospectively enrolled in our study. Quantitative CT analysis software was used to assess emphysema (LAA%), airway wall dimensions (wall area (WA), luminal area (LA), and wall area percentage (WA%)), and air trapping ((relative volume change of -860 HU to -950 HU (RVC-860 to-950) and the expiration-to-inspiration ratio of the mean lung density (MLDE/I))). Differences in pulmonary function and HRCT parameters were compared among the groups. Spearman correlation analysis and regression analysis were utilized to explore structure‒function relationships. The LAA% in COPD and ACO patients was significantly greater than that in asthmatic patients and controls. The WA% and WA in COPD and ACO patients were greater than those in controls, whereas the WA% and LA between asthmatic patients and controls reached statistical significance. The RVC-860 to -950 levels decreased in the following order: ACO, COPD, and asthma. RVC-860 to -950 independently predicted FEV1% in asthmatic patients; LAA% and MLDE/I in COPD patients; and LAA%, WA% and RVC-860 to -950 in ACO patients. Comparable emphysema was observed in patients with COPD and ACO but not in asthmatic patients. All patients exhibited proximal airway remodeling. The bronchi were thickened outward in COPD and ACO patients but are thickened inward in asthmatic patients. Furthermore, air trapping in ACO patients was the most severe among all the groups. Indirect lung densitometry measurements might be more predictive of the degree of airflow limitation than direct airway measurements in obstructive airway diseases.

Quality by design optimization and validation of a HPTLC-MS method for simultaneous estimation of paracetamol and prochlorperazine from bulk and formulation

Study reports that the, stability indicating high-performance thin layer chromatographic technique (HPTLC) was developed as well as validated for estimating Paracetamol and Prochlorperazine in bulk and dosage form. These drugs are largely used in migraine and first line treatment of schizophrenia. Selected drug combination employed for Quality by design based Box Behnken design by high performance thin layer chromatography method utilizing aluminium plates; pre-coated using silica gel 60F254 as stationary phase by using acetone: toluene: methanol (4:4:2 v/v/v) as a mobile phase. Densitogram shows Rf values for Paracetamol at 0.74 and for Prochlorperazine at 0.32 evaluated by densitometry measurement bands at 248 nm. Paracetamol and Prochlorperazine marketed formulation of 700 mg by using various excipients prepared at lab scale and it was evaluated for various types of tablet tests, and it showed the accurate result with respect to standard guidelines. The approach has been validated in accordance with International Conference on Harmonization (ICH) requirements. The correlation coefficient was found to be 0.992 and 0.998 at a concentration range of 100–300 μg/band and 1000–3000 ng/band for Paracetamol and Prochlorperazine, respectively. The method had an accuracy of 100.51 % and 100.53 % for Paracetamol and Prochlorperazine, respectively. The degradation of Paracetamol and Prochlorperazine was carried out in an acid, alkaline, oxidative, thermal and photolytic environment. The stress degraded product was successfully separated using the HPTLC and using high resonance mass spectroscopy technique (HRMS-MS), the degradation product was discovered.

Developmental changes in tibia and humerus of goose: morphometric, densitometric, and mechanical analysis.

The skeletal system of young animals undergoes a series of intensive and rapid changes. In this study, we aimed to verify the hypothesis that geese exhibit a distinct pattern of bone growth compared to gallinaceous species. Specifically, we hypothesised that geese would experience an accelerated growth rate in the humerus bone, which can be attributed to the increased wing mobility facilitated by their rearing in free-range systems. This need for access to both ground and water environments contributes to the unique demands placed on their skeletal development. We focused on evaluating the mechanical properties and geometry of the humerus as the forelimb bone, and the tibia as the hindlimb bone. The 320 geese used in this study were divided into 12 groups according to sex (females and males) and age (0-,1-,3-,6-,8-,12-,14-week-old). To assess bone mechanical properties, a three-point bending test was performed, along with densitometry and morphological measurements. The tibiae of the geese showed the most intensive growth until 6weeks of age and then stabilised. The wing bones (humerus) showed only slight changes in the first weeks after hatching, and then a rapid growth between the third and sixth week, both in terms of mechanical and morphological properties. This is most likely due to a change in the geese's living environment during this period, i.e., allowing them to leave their enclosures and enter open space, which gives them the opportunity to use their wings, resulting in the rapid growth of the wing bones to support increasing muscle mass in this area. This study increases our understanding of bone growth and development in domesticated birds, specifically waterfowl species, and highlights the importance of rearing methods on the proper bone development and functionality of the entire skeletal system, and thus, on their welfare.

The Effect of Entecavir and Tenofovir Disoproxil on Bone Mineral Density in Chronic Hepatitis B Treatment

Background/Aim:Evaluation of the relationship between drugs and osteoporosis in patients receiving entecavir (ETV) or tenofovir disoproxil fumarate (TDF) treatment for chronic hepatitis B infection (CHB).&#x0D; Material and Method: The study included patients who received ETV or TDF treatment for at least 12 months between 2016 and 2021 and underwent bone mineral densitometry (BMD) measurement within 12 months after treatment. Demographic characteristics of the patients and the association of antiviral drug use with osteopenia/osteoporosis were retrospectively.&#x0D; Results: The study included 170 patients, 92 (54.1%) of whom were male, with a mean age at diagnosis of 36.57 ± 14.88 years. Of the patients, 24 (14.1%) were on ETV and 146 (85.9%) were on TDF. The mean age at BMD measurement was 48.62 ± 13.4 years. The median time from diagnosis to BMD was 138.5 (15-373) months. Osteopenia/osteoporosis was found in 14 (15.2%) of male patients and 25 (32.1%) of female patients. The frequency of osteopenia/osteoporosis was significantly higher in women (p=0.011). There was no significant difference in the frequency of osteopenia/osteoporosis between ETV and TDF (p=0.112). Lumbar spine (LS) BMD was significantly higher in TDF users (p=0.043). While no patient had a BMD within 12 months of treatment initiation, 6 (3.5%) of the patients had a BMD within 24 months, 8 (4.7%) within 36 months and 25 (14.7%) within 60 months of treatment initiation.&#x0D; Conclusion: There was no significant difference in the development of osteopenia/osteoporosis in patients using TDF and ETV. It was found that bone mineral measurements of patients with CHB were not performed regularly and appropriately.

Characteristics of Wires of the Long-Operated Aluminum-Steel Cable at Different Places on an Overhead Power Line Span

During operation, cables of overhead power lines (OPLs) are exposed to the impact that differs in separate parts of the OPL span due to the different responses of cables near the clamps and far from them. This paper presents the results of a study of aluminum and steel wires cut from such separate parts of ACSR cables before and after exploitation. Structural, microstructural, and elastic–microplastic properties of wires and their changes during operation were studied through optical microscopy, energy-dispersive X-ray microanalysis, electron backscattering diffraction, X-ray diffraction, densitometry, and acoustic measurements. The characteristics of the properties of the wires along the span were found to change in a coordinated manner. Numerical estimates of the influence of the steel core on aging the ACSR cable were obtained. Changes in the properties of the wires, as well as oxidization and corrosion of their near-surface layers, were studied in detail. Quantitative values of the characteristics of properties, the most distant from those observed in the new wires, were revealed for samples of aluminum and steel wires cut from the cable at 1/4 span and near clamps. It is assumed that these cable parts should be the most crucial for cable durability.

P-643 The effect of hyperinsulinemia on FSH-mediated signalling pathways in granulosa cells - implications for follicle growth in women with PCOS

Abstract Study question Does in vitro exposure of granulosa cells (GC) to an equivalent hyperinsulinemic (HI) dose of insulin alter key signalling pathways, potentially slowing follicle growth? Summary answer Exposure of GC to HI dose of insulin down-regulated FSH-mediated phosphorylation of AKT and ERK proteins, which was reversed by metformin but not myoinositol treatment What is known already Antral follicles utilise glycolytic methods of energy production releasing the metabolites pyruvate and lactate, which are then secreted into the follicular fluid or passed directly to the oocyte via gap junctions. Insulin increases GC glucose uptake and cross-talks with FSH-mediated intracellular pathways that determine follicle growth and glucose utilisation. We and others have shown that there is significant perturbation in glucose metabolism (as measured by reduced lactate production) in cultured luteinised GC (GLC) from women with anovulatory PCOS, compared to those with normal ovaries or polycystic ovarian morphology (PCOM), that represents both attenuated glucose uptake and reduced glycolytic activity. Study design, size, duration KGN-GC were exposed to 1000ng/ml insulin for 48h (mimicking prolonged HI in vivo) with/without metformin [10-7M] or myo-inositol [25mM]; followed by acute stimulation with FSH (10ng/ml at 15 and 30 mins) (n = 4-5). GLCs obtained from women with normal ovaries (n = 5), PCOM (n = 7) and PCOS (n = 2) were serum-starved and exposed acutely to insulin (10ng/ml for 30mins), glucose starved (20mins) and treated with a radiolabelled 2-deoxy-glucose mix. Fasting serum glucose and insulin were measured in PCOS women. Participants/materials, setting, methods Western blotting on proteins from KGN-GC was performed using antibodies against total and phosphorylated forms of AKT and ERK. Densitometry measurements of phospho:total forms were taken from individual treatments, normalised to loading controls (either β-actin/Vinculin) and then untreated controls. GLCs were lysed and uptake of 14C-2DG (non-metabolised) measured and expressed as percentage uptake of 14C-2DG in the insulin-treated normalised to untreated/control cells (100%). Insulin resistance (IR) was calculated from fasting glucose and insulin using HOMA2. Main results and the role of chance Chronic exposure of KGNs to high dose insulin significantly down-regulated acute FSH-mediated phosphorylation of AKT and ERK (ANOVA *p=0.03, multiple post-hoc t-tests p &amp;lt; 0.05, two-tailed), without altering insulin receptor levels. Addition of metformin to FSH treatment, significantly reversed the HI-induced reduction in pAKT levels and enhanced it further (*p=0.02) but had no effect on pERK levels. Myoinositol had no effect on either pAKT or pERK levels. These findings demonstrated that HI directly inhibited FSH signalling events downstream of the insulin receptor in GC, but that metformin could counteract some of these detrimental effects. The 2-deoxy form of glucose is taken up into the cell but not metabolised further. Measurement of 14C-2DG showed that acute stimulation with post-prandial levels of insulin of GLCs taken from normal and PCOM women significantly increased glucose uptake (*p&amp;lt;0.05, ratio of paired t-test, 2-tailed); whereas GLCs from women with PCOS and insulin resistance were unable to respond to insulin and take up glucose. Therefore, GLCs from insulin resistant women with PCOS retain their phenotype in vitro and this is not an artefact, since GLCs from normal and PCOM also subjected to the same stimulation regime were able to take up glucose in response to insulin stimulation. Limitations, reasons for caution A clear limitation is the small number of insulin resistant women with PCOS. In addition, human GLCs were collected after hormonal stimulation. Wider implications of the findings Women with IR, HI and PCOS undergoing ART may require extra gonadotrophin stimulation to grow and mature sufficient eggs. Additionally, the oocyte quality maybe compromised, as indicated by reduced glucose uptake. Treatment of women with metformin but not myoinositol may improve the dysregulated FSH-signalling pathways brought about by HI. Trial registration number not applicable

High-intensity interval training prevents muscle mass loss in overweight Chilean young adults during a hypocaloric-Mediterranean diet: a randomized trial.

The hypocaloric Mediterranean diet (MD) mainly reduces fat mass but inevitably causes a loss of skeletal muscle mass. High-intensity interval training (HIIT) seems to have advantages in preserving muscle mass during a hypocaloric regime. Our study compares body composition and metabolic changes in overweight and obese Chilean women and men after 3 months of weight loss treatment with a Mediterranean-type hypocaloric diet, HIIT, or a combination of both. The study included 83 overweight or obese women and men between the ages of 25 and 50. The subjects were randomly assigned to one of the three intervention groups: (1) MD, (2) EX, and (3) MD + EX. Baseline and post-intervention measurements included: (a) body composition by dual-beam densitometry, muscle, and fat measurements by thigh ultrasound and computed tomography; (b) handgrip and quadriceps muscle strength; (c) exercise performance by peak oxygen consumption, peak load, work efficiency, and exercise energy expenditure; and (d) metabolic parameters. Out of 83 participants, the retention rate was 49% due to low compliance with the interventions. As expected, the MD group resulted in significantly greater weight loss (MD -7%, EX -0.6% and MD + EX -5.3%) and appendicular fat mass loss (MD -11.1%, EX -2.9, MD + EX -10.2%) but was associated with significant lean tissue loss (2.8%), which was prevented by HIIT (EX -0.1 and MD + EX -0.6%). Metabolic and glycoxidative parameters remained unchanged, irrespective of changes in body composition. Hypocaloric diets remain the most effective means to lose weight and body fat. However, it induces a loss of lean body mass when not accompanied by exercise training. This study shows that HIIT prevents the loss of muscle mass caused by a hypocaloric Mediterranean diet.

The intra- and inter-day repeatability of corneal densitometry measurements in subjects with keratoconus and in healthy controls

The healthy cornea is transparent, however, disease can affect its structure, rendering it more or less opaque. The ability to assess the clarity of the cornea objectively could thus be of considerable interest for keratoconus patients. It has previously been suggested that densitometry can be used to diagnose early keratoconus, and that the values of densitometry variables increase with increasing disease severity, indicating that densitometry could also be used to assess progressive keratoconus. Previous studies have only assessed the repeatability of corneal densitometry measurements on the same day, which does not reflect the clinical setting in which changes are evaluated over time. We have therefore evaluated the inter-day repeatability of densitometry measurements in both patients with keratoconus and healthy controls. Measurements in the middle layer of the 2–6 mm zone of the cornea showed the best repeatability. Although an objective measure of the corneal transparency could be interesting, the generally poor repeatability of densitometry measurements limits their use. The repeatability of corneal clarity measurements could be improved by using other approaches such as optical coherence tomography, but this remains to be investigated. Such improvements would allow the more widespread use of corneal densitometry in clinical practice.

Effects of Descemet Stripping Automated Endothelial Keratoplasty on Corneal Densitometry of Cases with Long-Standing Pseudophakic Bullous Keratopathy.

To quantify the effects of Descemet stripping automated endothelial keratoplasty (DSAEK) on corneal clarity and densitometry of patients with long-standing pseudophakic bullous keratopathy (PBK) complicated with subepithelial fibrosis. Thirty-four eyes with PBK complicated with corneal edema for more than 6 months and subepithelial fibrosis were enrolled. All subjects underwent complete ophthalmic examination and corneal densitometry module of Pentacam HR, before and 1, 3, and 6 months after DSAEK. Thirteen patients were excluded due to postoperative complications or missed to follow-up visits. Finally, twenty-one patients' data were analyzed. Corneal densitometry measures significantly decreased in all three layers (anterior, central, and posterior) 3 and 6 months after surgery compared to preoperative values; however, the differences did not reach statistical significance in the 1st month. Moreover, densitometry measurements were significantly lower at month 6 compared to month 1, but not at month 3 compared to month 1. Corneal densitometry of the anterior layer was significantly higher than central and posterior layers in 2 mm and 6 mm zones preoperatively and at all postoperative visits. Corneal light backscatter of each three layers was not statistically different between 0-2 mm and 2-6 mm in all pre- and postoperative visits. Corneal densitometry in cases of PBK begins to improve after DSAEK in different layers in a slow and continued trend which takes up to 6 months for an effect to be seen. Interestingly, this improvement is possible even in complicated corneas with long-standing edema. Hence, corneal densitometry can be used as an objective method for quantification of the outcome of DSAEK in complicated cases of PBK.

Analytical Method Development and Validation of Hptlc Method for Simultaneous Estimation of Telmisartan and Azelnidipine in Tablet Dosage Form

Background: A specific, accurate, precise, robust and cost effective HPTLC method was developed and validated for quantitative analysis of Telmisartan and Azelnidipine in fixed dose combination. The separation was carried out on pre-coated TLC plates with Silica gel 60 F254 as stationary phase using Chloroform: Ethyl acetate: Methanol (7.5:2:0.5 v/v/v) as developing system followed by densitometry measurement of bands at 280nm. Result: The separation of Telmisartan and Azelnidipine was found to be at the following RF values 0.3 and 0.63 respectively. Calibration curves were found to be linear over the concentration ranges 400-4000ng/band, 80-800ng/band for Telmisartan and Azelnidipine with correlation coefficient 0.9957 and 0.9966 respectively. Accuracy was found between 98.03% - 102% and 98.72% - 102 % for Telmisartan and Azelnidipine respectively. LOD was found to be 1.04% and 1.6% and LOQ was found to be 3.49% and 5.57% for Telmisartan and Azelnidipine respectively Conclusion: The results showed that the proposed HPTLC method is reliable for routine analysis for simultaneous determination of Telmisartan and Azelnidipine without any interference.

Effect of a Contrast Agent on Bone Mineral Density Measurement in the Spine and Hip Using QCT-Conversion Factor Recommendation.

Osteoporosis causes an increased fracture risk. Clinically, osteoporosis is diagnosed late, usually after the first fracture occurs. This emphasizes the need for an early diagnosis of osteoporosis. However, computed tomography (CT) as routinely used for polytrauma scans cannot be used in the form of quantitative computed tomography (QCT) diagnosis because QCT can only be applied natively, i.e., without any contrast agent application. Here, we tested whether and how contrast agent application could be used for bone densitometry measurements. Bone mineral density (BMD) was determined by QCT in the spine region of patients with and without the contrast agent Imeron 350. Corresponding scans were performed in the hip region to evaluate possible location-specific differences. Measurements with and without contrast agent administration between spine and hip bones indicate that the corresponding BMD values were reproducibly different between spine and hips, indicating that Imeron 350 application has a location-specific effect. We determined location-specific conversion factors that allow us then to determine the BMD values relevant for osteoporosis diagnosis. Results show that contrast administration cannot be used directly for CT diagnostics because the agent significantly alters BMD values. However, location-specific conversion factors can be established, which are likely to depend on additional parameters such as the weight and corresponding BMI of the patient.

Subjective and objective evaluation of corneal haze after accelerated corneal crosslinking for corneal ectasias.

To evaluate the relationship between subjective (slit lamp examination [SLE]) and objective (densitometry) measurements of corneal haze after accelerated corneal crosslinking (aCXL), assess the relationship between densitometry and corrected distance visual acuity (CDVA), and determine the effect of baseline characteristics on densitometry after aCXL in eyes with progressive keratoconus and other ectasias. Kensington Eye Institute and Bochner Eye Institute, Toronto, Canada. Retrospective analysis of a prospective interventional cohort study. Scheimpflug-derived corneal densitometry, CDVA, maximum keratometry (Kmax ), and central corneal thickness were measured preoperatively and up to 1year after aCXL, and post-operative haze was estimated with SLE (n=483 eyes). A random effect model was used to examine the relationship between post-operative subjective haze with SLE and densitometry. Linear mixed models were used to examine the relationship between densitometry, pre-operative baseline characteristics, and CDVA. There was a significant association between subjective haze with SLE and densitometry (p < 0.001). There was a significant relationship between CDVA and densitometry: for every 10 GSUs of increased densitometry in the 0-2 mm zone, CDVA worsened by approximately half a Snellen line (p < 0.001). Age and pre-operative Kmax were significant predictors of densitometry. For every 10 years of age, densitometry increased by 0.68 GSUs (95% CI [0.27 to 1.07], p < 0.001). For every 10 D of increased preoperative Kmax , densitometry increased by 0.69 GSUs (95% CI [0.41 to 0.98], p < 0.001). Subjective haze after aCXL estimated with SLE, is significantly associated with densitometry. Increased densitometry after aCXL is associated with a reduction in CDVA.

Corneal Densitometry to Assess the Corneal Cystine Deposits in Patients With Cystinosis.

The purpose of this study was to assess the suitability of corneal densitometry measurements obtained with Scheimpflug imaging in estimating the corneal changes caused by cystine deposits in the cornea in patients with cystinosis. Scheimpflug imaging (Pentacam) was performed for 14 patients with cystinosis and 16 age-matched controls. Pentacam data were used for analysis of the corneal densitometry at different zones in the cornea for patients with cystinosis and controls. Densitometry measurements were compared with the corneal crystal scores obtained from the slitlamp images for patients with cystinosis. There was no statistically significant difference in keratometry measurements between the 2 groups ( P > 0.05). Corneal thickness was found to be significantly higher in the control group when compared with the cystinosis group ( P = 0.0004). The mean corneal densitometry was significantly higher in patients with cystinosis when compared with controls at most of the corneal layers and zones. The corneal densitometry readings for the right and left eyes showed moderate positive correlation with the corneal crystal score with a ceiling effect being reached at the maximum corneal crystal score of 3. Corneal densitometry obtained through Pentacam can be used as an objective estimate of the level of cystine crystals present in patients with cystinosis. The clinical estimate of corneal crystal score, although effective at low levels of crystal deposition, does not allow for accurate estimates of change when the level of crystal deposition is high leading to limited utility when assessing treatment effects. Hence, densitometry measurements can potentially be used to assess treatment efficacy of cystinosis treatments in clinical settings.