The scope of the cataract problem in the Middle East and the Mediterranean

The region is characterized by diversity in cultural, political, economic and health conditions. Blindness in the region varies from 6.4% to 0.2% with cataract ranking highly as an underlying cause. There is a need to develop national policies to deliver affordable, technically suitable, and cost effective management plans to reduce cataract. Economic, demographic, health, and manpower statistics are essential information to be considered in formulating such policies.     

An alternative approach to acid base abnormalities in critically ill patients

Contin Educ Anaesth Crit     

Maximal dynamic expiratory pressures with fast and slow inspirations

Maximal dynamic expiratory pressures are higher when forced expiration is preceded by a fast inspiration to total lung capacity (TLC) than when preceded by a slow inspiration and a few seconds pause at TLC. We hypothesized that these pressure differences are due to the stretch-shorten cycle (SSC), which refers to enhancement of muscle force when a concentric muscle contraction is immediately preceded by an eccentric contraction. Seven volunteers [36 (2) years; mean (SEM)] performed maximal forced expirations against minimal resistance with fast (F) or slow (S) maneuvers. F maneuvers consisted of a fast inspiration to TLC followed immediately by a fast expiration, whereas S consisted of a slow inspiration to TLC and a 4- to 5-s pause at TLC prior to forced expiration. We measured esophageal pressure (P _es), peak expiratory flow rate (PEFR), and the EMG activity of the transversus abdominis (Tr) by means of intramuscular fine-wire electrodes. The subjects performed several runs of each maneuver in a random order, and runs with the greatest expiratory P _es were analyzed. In comparison with S, F yielded greater P _es [182 (15) versus 167 (15) cmH₂O; P=0.003)] but similar PEFR [9.8 (0.7) versus 9.6 (0.7) l/s, P>0.05] and EMG activity of the Tr during forced expiration [221 (31) versus 208 (34) a.u., P>0.05]. Further analysis revealed significant EMG activity of Tr during end-inspiration (eccentric contraction) with F maneuvers only [73 (22) versus 32 (17) a.u., P<0.05]. We conclude that the ability of expiratory muscles to generate greater P _es with F maneuvers is related to the sequence of an eccentric contraction, which is followed immediately by concentric contraction in a manner analogous to SSC described in skeletal muscles. Electronic Publication     

Investigating Population Risk Factors of Pancreatic Cancer by Evaluation of Optical Markers in the Duodenal Mucosa

Pancreatic cancer screening has been hampered by the high rate of complications associated with interrogating the pancreas. The closest non-invasively accessible mucosa available for pancreatic cancer screening is the periampullary duodenal tissue. Our earlier report has shown the potential of using optical markers to interrogate this tissue for the presence of pancreatic cancer. In this study, we report a larger data set of low-coherence enhanced backscattering (LEBS) and elastic light scattering fingerprinting (ELF) optical markers from the periampullary duodenal mucosa. Optical measurements from biopsy samples were acquired from a total of 203 patients with varying clinical classification including healthy controls, a family history of pancreatic cancer, pancreatitis, mucinous cystic precursor lesions, pancreatic cancer, and other pancreatic malignancies. Evaluation of the performance of an independent testing set for discriminating healthy control patients from pancreatic cancer patients showed a 95% sensitivity, 71% specificity, and 85% area under the receiver operator characteristic (AUROC) curve. Importantly, this performance was uncompromised for detecting potentially curable stages of the disease. Additionally, optical markers in higher risk populations such as family history and pancreatitis had values between those of healthy control and pancreatic cancer patients, thus allowing for future investigations of screening from these high risk groups.     

Methimazole in the Treatment of Melasma: A Clinical and Dermascopic Study

BACKGROUND: Melasma is a chronic hypermelanotic disorder that is challenging to treat; no single effective therapeutic agent for it has been discovered. Methimazole, an oral antithyroid drug, has a skin depigmenting effect when used topically. OBJECTIVE: We sought to evaluate the efficacy and safety of methimazole, applied during microneedling sessions and additional topical use in between sessions, for the treatment of melasma. METHODS: This split-face study included 30 Egyptian patients with melasma, each of whom received 12 microneedling sessions once per week for 12 weeks followed by topical methimazole on the right side of face and placebo on the left side. In between the sessions, topical methimazole 5% cream was applied twice per day on the right side and placebo on the left side. Assessments were performed using the Hemi-melasma Area and Severity Index (hemi-MASI) percentage of improvement, patient satisfaction, dermoscopy, and thyroid-stimulating hormone (TSH) serum levels. RESULTS: There were significant clinical and dermoscopic improvements; hemi-MASI scores on the methimazole-treated right sides were decreased (p<0.001). The percent of hemi-MASI score improvement was significantly associated with the malar pattern (p=0.031) and epidermal type (p=0.04) of melasma. About 70 percent of our studied patients reported being satisfied with their treatment response (7% excellent, 33% good, 30% fair). No significant local or systemic side effects were observed. Pre- and posttreatment serum TSH levels were within the normal range in all treated cases. CONCLUSIONS: Methimazole has the potential to be a safe and promising therapeutic agent for the treatment of melasma via dermapen-delivered microneedling sessions with topical use in between sessions.     

A nuclear gene of eubacterial origin in Euglena gracilis reflects cryptic endosymbioses during protist evolution.

Genes for glycolytic and Calvin-cycle glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of higher eukaryotes derive from ancient gene duplications which occurred in eubacterial genomes; both were transferred to the nucleus during the course of endosymbiosis. We have cloned cDNAs encoding chloroplast and cytosolic GAPDH from the early-branching photosynthetic protist Euglena gracilis and have determined the structure of its nuclear gene for cytosolic GAPDH. The gene contains four introns which possess unusual secondary structures, do not obey the GT-AG rule, and are flanked by 2- to 3-bp direct repeats. A gene phylogeny for these sequences in the context of eubacterial homologues indicates that euglenozoa, like higher eukaryotes, have obtained their GAPDH genes from eubacteria via endosymbiotic (organelle-to-nucleus) gene transfer. The data further suggest that the early-branching protists Giardia lamblia and Entamoeba histolytica--which lack mitochondria--and portions of the trypanosome lineage have acquired GAPDH genes from eubacterial donors which did not ultimately give rise to contemporary membrane-bound organelles. Evidence that "cryptic" (possibly ephemeral) endosymbioses during evolution may have entailed successful gene transfer is preserved in protist nuclear gene sequences.     

Biology of senescent liver peroxisomes: role in hepatocellular aging and disease.

Despite rising interest in the health problems of the elderly, information on senescence-related alterations in essential metabolic pathways and their responses to various chemicals is scarce. Although peroxisomal pathways are involved in a multitude of cellular functions, little attention has been given to the potential relationship between senescence of these organelles and the process of aging and disease. Although the prevailing experimental evidence points to a decline in liver peroxisomal enzyme activities and a muted response to peroxisome-proliferating chemicals in aged animals, it is also evident that aged animals are more susceptible, in comparison to their young counterparts, to the hepatocarcinogenic effects of these chemicals. Furthermore, little is known about extraperoxisomal effects of peroxisome proliferators in aged animals. This review evaluates published studies on the impact of aging on basal hepatic peroxisomal metabolism, response to peroxisome proliferators, and changes in signal transduction pathways involved in these processes, with the aim of stimulating research efforts in this important area. The potential intricate relationship among senescent peroxisomes, aged hepatocytes, and health are also discussed.