Defining epithelial cell progenitors in the human oxyntic mucosa

In the human stomach, the oxyntic epithelium includes numerous tubular invaginations consisting of short pits opening into long glands. The pit is lined by pit cells, whereas the gland is composed of three regions: the base, containing zymogenic cells; the neck, containing neck cells; and the isthmus, composed of little known immature cells and of parietal cells, which are also scattered through the neck and base. The aim of this study was to examine the ultrastructure of the immature cells and to determine their relation to mature cells. To do so, normal oxyntic mucosal biopsies from subjects ranging from 20-43 years old were fixed in aldehydes and postfixed in reduced osmium for electron microscopy and morphometric analysis. The immature cells were sorted out into four classes, whose roles were clarified by comparison with the thoroughly investigated mouse oxyntic epithelium. The first class was composed of the least differentiated immature cells, which were rare and characterized by minute, dense, or cored secretory granules and were accordingly named mini-granule cells. Their function was not clarified. The second class consisted of pre-pit cells, which were characterized by few dense mucous granules and give rise to pit cells that ascend the pit wall and, after reaching the luminal surface, die or are extruded. Both pre-pit and pit cells underwent continuous renewal and, therefore, together constituted a renewal system referred to as pit cell lineage. The third class, or pre-neck cells, characterized by cored secretory granules, give rise to neck cells that descend toward the base region and differentiate further into pre-zymogenic cells, which finally become zymogenic cells. The latter eventually degenerate and die. Thus pre-neck cells and their progeny constitute a renewing system, designated zymogenic cell lineage. The fourth class, or pre-parietal cells, characterized by long microvilli and few tubulovesicles, differentiate into parietal cells that descend along the neck and base regions and eventually degenerate and die. Pre-parietal and parietal cells represent a renewing system referred to as parietal cell lineage. While the origin of the last three classes of progenitor cells has not been elucidated, it is likely that they arise either from an unidentified multipotential stem cell, possibly the mini-granule cell itself, or from the mitotic activity of pre-pit and pre-neck cells. In conclusion, the human oxyntic epithelium is composed of continually renewing cells organized in distinct cell lineages.     

Effect of age on left ventricular systolic function in humans: a study of systolic isovolumic acceleration rate

The aim of this study was to examine the effect of age on left ventricular (LV) systolic function in normal healthy adults. Eighty consecutive subjects without cardiovascular disease underwent standard and tissue Doppler (TD) echocardiographic imaging. LV systolic function was assessed by load-dependent indices as ejection fraction (EF) and myocardial systolic velocities by TD as well as by the load-independent index, systolic isovolumic acceleration rate (IVA). None of the echocardiographic measurements of systolic function declined with age (mean IVA for the group, 286 +/- 123 cm s(-2); IVA vs. age, r = 0.21, P = 0.1). Likewise, LV end diastolic dimension, wall thickness, mass and left atrial maximum volume were not significantly related to age. On the other hand, as previously reported, echocardiographic indices of diastolic function showed a significant decline with age (P < 0.05). When the group was stratified by gender, isovolumic velocity and acceleration were higher in men than women, but the differences were not significant (P = 0.12 and 0.37, respectively). No significant relation was observed between age and measurements of LV systolic function by regression analysis in women (P > 0.1). However, in men, a positive correlation was noted between average IVA and age (r = 0.63, P = 0.007). In conclusion, age is not associated with a change in cardiac structure and LV systolic function, but is accompanied by a decline in echocardiographic indices of diastolic function. With respect to gender, age does not appear to influence LV systolic function in women, but is associated with an increase in IVA and septal systolic ejection in men.     

The Effect of Neonicotinoids Exposure on Oreochromis niloticus Histopathological Alterations and Genotoxicity

This study aimed to examine the side effects of selected neonicotinoids (Acetamiprid, Aceta, and Imidacloprid, Imid) on Oreochromis niloticus juveniles. The acute toxicity, Probit method, revealed an LC₅₀ of 195.81 and 150.76 ppm for Aceta/96 h and Imid/72 h respectively. The fish were divided into three groups that were exposed, for 21 days (n?=?5/replicate), to 1/10 of the LC₅₀ of either neonicotinoids, however, the third was an unexposed control group. Results of erythrocytic micronucleus (MN), and nuclear abnormalities (NA) showed that Aceta and Imid exposure caused a significant (p?<?0.05) increase in MN by?~?2.2 and?~?10 folds, respectively relative to control. NAs occurred at the order of kidney-shaped?>?budding?>?binucleated in Aceta, however, budding?>?binucleated?>?kidney-shaped was noticed in the Imid group. Histopathological changes in gills, liver, and muscles were observed significantly in both exposed groups with more severity in the Imid group. Collectively, Aceta and Imid have potential genotoxicity and histopathological alterations in O. niloticus.

     

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.     

Reliability of erector spinae oxygenation and blood volume responses using near-infrared spectroscopy in healthy males

The purpose of this investigation was to (1) describe the trends in oxygenation (OXY) and blood volume (BV) of the right and left paraspinal muscles during the Biering-Sorensen muscle endurance (BSME) test using near infrared spectroscopy (NIRS), and (2) assess the test-retest reliability of OXY and BV changes during the BSME in healthy males. Seventeen healthy males [age=28.4 (9.8) years, height=1.75 (0.05) m, body mass=82.7 (9.1) kg; mean (SD)] completed two BSME trials within 1 week. NIRS probes were placed bilaterally at lumbar 3. The test was performed with the subject in the prone position using the following protocol: 2 min baseline, BSME, and 4 min recovery. The delta and range values of OXY and BV were used for analysis. Acceptable intra-class correlations were observed for endurance time and all the NIRS variables at the point of fatigue and at each 10% segment of the BSME during the two trials. Bland-Altman plots confirmed the reproducibility of the bilateral NIRS responses of the paravertebral muscles. The BV responses were more reliable than the OXY responses during the two trials. The OXY and BV responses of the paravertebral muscles during static contractions can be measured reliably using NIRS. Future studies should focus primarily on BV for analysis.     

An indoor bio-contaminants air quality

Both the quantity and quality of microorganisms (mold, actinomycetes and bacteria) were investigated in the air of five clean rooms indoors, outdoor air sampling was a routine work of the present study. Total viable bacterial counts were recorded in a mean value of 103 cfu/m3, whereas mold counts ranged between 102-103 cfu/m3. The highest mold counts were recorded at some places investigated such as research laboratories and a library. Moreover, the types, percentages and frequencies of occurance of viable mold were studied. Penicillium, Cladosporium and Aspergillus were the predominant mold genera. These organisms are aeroallergens. Actinomycetes were detected in low numbers compared with other organisms (range between 0-102 cfu/m3). Yellow, grey and white colour series were dominant streptomycetes. The mold and streptomycetes spore sizes were measured microscopically. The sizes of major mold spores ranged between 2.5-10 mum, whereas that of streptomycetes spores ranged between 1.2-2.5 mum. The particles < 5 mum in sizes are likely to reach the alveoli which may elicit potential risk for exposed residents. However, a low number of air microorganisms does not mean a clean and healthy environment.     

Paclitaxel decreases the interstitial fluid pressure and improves oxygenation in breast cancers in patients treated with neoadjuvant chemotherapy: clinical implications.

PURPOSE: It has been hypothesized that tumors with high interstitial fluid pressure (IFP) and/or hypoxia respond poorly to chemotherapy (CT) because of poor drug delivery. Preclinical studies have shown that paclitaxel reduces the IFP and improves the oxygenation (pO(2)) of tumors. Our aim is to evaluate the IFP and pO(2) before and after neoadjuvant CT using sequential paclitaxel and doxorubicin in patients with breast cancer tumors of >/= 3 cm. PATIENTS AND METHODS: Patients were randomly assigned, according to an institutional review board-approved phase II protocol, to receive neoadjuvant sequential CT consisting of either four cycles of dose-dense doxorubicin at 60 mg/m(2) every 2 weeks followed by nine cycles of weekly paclitaxel at 80 mg/m(2) (group 1) or vice versa, with paclitaxel administered before doxorubicin (group 2). Patients were re-evaluated clinically and radiologically. The IFP (wick-in-needle technique) and pO(2) (Eppendorf) were measured in tumors at baseline and after completing the administration of the first and second drug. RESULTS: IFP and pO(2) were measured in 54 patients at baseline and after the first CT. Twenty-nine and 25 patients were randomly assigned to groups 1 and 2, respectively. Paclitaxel, when administered first, decreased the mean IFP by 36% (P = .02) and improved the tumor pO(2) by almost 100% (P = .003). In contrast, doxorubicin did not have a significant effect on either parameter. This difference was independent of the tumor size or response measured by ultrasound. CONCLUSION: Paclitaxel significantly decreased the IFP and increased the pO(2), whereas doxorubicin did not cause any significant changes. Tumor physiology could potentially be used to optimize the sequence of neoadjuvant CT in breast cancer.     

Influence of Tantalum Addition on the Corrosion Passivation of Titanium-Zirconium Alloy in Simulated Body Fluid

Ti-15%Zr alloy and Ti-15%Zr-2%Ta alloy were fabricated to be used in biomedical applications. The corrosion of these two alloys after being immersed in simulated body fluid for 1 h and 72 h was investigated. Different electrochemical methods, including polarization, impedance, and chronoamperometric current with time at 400 mV were employed. Also, the surface morphology and the compositions of its formed film were reported by the use of scanning electron microscope and energy dispersive X-ray. Based on the collected results, the presence of 2%Ta in the Ti-Zr alloy passivated its corrosion by minimizing its corrosion rate. The polarization curves revealed that adding Ta within the alloy increases the corrosion resistance as was confirmed by the impedance spectroscopy and current time data. The change of current versus time proved that the addition of Ta reduces the absolute current even at high anodic potential, 400 mV. The results of both electrochemical and spectroscopic methods indicated that pitting corrosion does not occur for both Ti-Zr and Ti-Zr-Ta alloys, even after their immersion in SBF solutions for 72 h.