Relationships between sex steroids of the seminal fluid and milt quality parameters of Persian sturgeon, Acipenser persicus Borodin, 1897

To investigate the role of sex steroids of the seminal fluid on sperm quality, the relationships between sex steroids and milt quality parameters (sperm motility and sperm production) were investigated in the Persian sturgeon. The seminal fluid levels of 17α,20β,21-trihydroxy-4-pregnen-3-one (20βs), and 11-ketotestosterone (11-KT) had positive relationships with sperm motility characteristics (percentage and duration of motility) and sperm density. Also, no relationships were found between other sex steroids including: Testosterone (T), progesterone (P), 17α-hydroxyprogesterone (OHP), and milt quality parameters. The good correlation of 20βs and 11-KT of the seminal fluid with sperm motility and sperm density suggests that these steroids may be important hormones involving in final maturation of the Persian sturgeon spermatozoa.     

Cellular and molecular interactions between MC3T3-E1 pre-osteoblasts and nanostructured titanium produced by high-pressure torsion

Ultra-fine surface features are commonly used to modulate cellular activity on a variety of materials. The continuing challenge for materials in contact with bone is the development of a material with both favorable surface and bulk properties to modulate not only the cell-substrate interactions, but also to ensure the long-term stability of the implant. In a combined approach involving material sciences and cell and molecular biology, the nature and mechanism of cell-substrate interaction, in particular, the molecular machinery controlling cell response to the surface of the nanostructured titanium based material produced by the high pressure torsion (HPT) process is assessed. The degree of pre-osteoblast attachment and rate of growth, which are regulated through the activity and interaction of proteins present in the extracellular matrix and associated with cytoskeleton and focal adhesion, are notably increased on the HPT-processed titanium substrates. The improved cell activity is attributed to the nanostructured feature of these substrates consisting of ultra-fine crystals (<50 nm) and a distinct surface oxide layer which provide higher degree of surface wettability. These findings demonstrate the advantages of HPT-processed titanium over the conventional and coated titanium implants, as both mechanical properties and cellular response are improved.     

The significance of crystallographic texture of titanium alloy substrates on pre-osteoblast responses

The aim of this study is to investigate the effects of grain orientation in polycrystalline materials on cell-substrate interactions. Samples are prepared from rods and sheets of Ti-6Al-4V substrates with predominately two distinct crystallographic orientations. X-ray diffraction analysis indicates that 36% of the surfaces of rod samples consist of (1010) plane, while the predominant orientation in the surface of the sheet samples is (1120) plane (29%). Morphological studies and cell biological experiments including cell attachment, proliferation and differentiation are conducted using MC3T3 pre-osteoblast cells cultured on these two different samples. The number of attached cells on the rod Ti-(1010) samples (70% after 1 h and 50% after 2 h) is higher than on the sheet Ti-(1120) samples. Cell proliferation after 3 days is also significantly higher on the Ti-(1010) samples. Alkaline phosphatase activity, however, shows no significant difference between the two samples. Scanning electron microscopy (SEM) analysis of MC3T3 cells grown on samples with different crystallographic texture demonstrate significant differences in morphology with respect to attachment and growth pattern. This study shows that crystal orientation of the substrate can influence cell responses and, therefore, substrate engineering can be used to improve and control cell-substrate interactions.     

Gigantism in unique biogenic magnetite at the Paleocene-Eocene Thermal Maximum

We report the discovery of exceptionally large biogenic magnetite crystals in clay-rich sediments spanning the Paleocene-Eocene Thermal Maximum (PETM) in a borehole at Ancora, NJ. Aside from previously described abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite up to 4 microm long and hexaoctahedral prisms up to 1.4 microm long. Similar to magnetite produced by magnetotactic bacteria, these single-crystal particles exhibit chemical composition, lattice perfection, and oxygen isotopes consistent with an aquatic origin. Electron holography indicates single-domain magnetization despite their large crystal size. We suggest that the development of a thick suboxic zone with high iron bioavailability--a product of dramatic changes in weathering and sedimentation patterns driven by severe global warming--drove diversification of magnetite-forming organisms, likely including eukaryotes.     

Modified synthesis of 11-[C]-clozapine

The reported synthetic pathway of 8-chloro-11-(4-methyl-1-piperazinyl)-11-[¹⁴C]-5H-dibenzo[b,e][1,4]diazapine (clozapine) was modified in several steps. The synthetic pathway was shortened by 60% and the total yield was increased from 6% to 23%.     

Psychometric properties of the Persian version of the Questionnaire of Cognitive Schema Activation in Sexual Context (QCSASC) in unsuccessful sexual situations

The aim of this study was to translate and adapt to Persian, and to assess psychometric properties of the Questionnaire of Cognitive Schema Activation in Sexual Context (QCSASC). A total of 265 Iranian participants (121 women and 144 men) were recruited for this study. A principal component analysis (PCA) with varimax rotation and subsequent confirmatory factor analysis revealed a best fitting five-factor structure similar to the original QCSASC: Incompetence, Undesirability, Abandon/Rejection, Powerless/Helpless, and Difference. However, in the Iranian sample, the original Self-Depreciation dimension was included in the Incompetence and Undesirability factors. An Abandon/Rejection dimension was also evident, and may be explained by cultural, social, and religious factors in the Iranian culture. Additionally, reliability analysis has supported the internal consistency (adequate Cronbach's alpha values) and temporal stability (test–retest reliability) of the QCSASC in an Iranian sample. The findings suggest the adequacy of the Persian version of the QCSASC to assess cognitive schemas in sexual context among Iranian men and women.     

COVID‐19‐associated mucormycosis involving the maxilla

It is important to increase the awareness and knowledge of head and neck surgeons about the recent surge of craniofacial mucormycosis in COVID‐19 patients because early diagnosis and appropriate treatment are essential to improve the outcomes. Here, we describe clinical features, treatment protocols, and outcomes of treatment in eight patients with COVID‐19‐associated mucormycosis in the maxilla. Consistent with the findings of previous studies, our experience in the management of these eight patients shows that early administration of amphotericin B and prompt aggressive surgery are essential for optimal control of the disease.     

Nurses experiences in chemical emergency departments: Iran–Iraq war, 1980–1988

BackgroundNurses have played a major role in taking care of the wounded across the centuries. One of the most important roles of Iranian nurses in wartime has been working in chemical emergency departments. This study investigated the nature of nursing practice in chemical emergency departments created in the context of the Iran–Iraq War fought during 1980–1988.MethodThis is a history methodology design with oral history and in-depth interview to detect nurses ‘actual experiences in chemical emergency departments while taking care of the chemically injured military forces.FindingsToday’s nurses emphasize finding new ways to fulfill the present nursing needs and to combine theory and practice in an appropriate framework.Having a retrospective approach to utilize nurses’ experience can well clarify the future way to achieve this goal.ConclusionThis study revealed the way the nurses prepared to take care of the chemically injured in miserable situations and their practice in chemical emergency departments. It highlighted their awareness of wartime nursing and the challenging experiences it brings.     

Smooth muscle cells deficient in osteopontin have enhanced susceptibility to calcification in vitro

OBJECTIVE: Vascular calcification is an actively regulated process, correlating with cardiovascular morbidity and mortality especially in patients with diabetes and chronic renal diseases. Osteopontin (OPN) is abundantly expressed in human calcified arteries and inhibits vascular calcification in vitro and in vivo. How OPN functions in vascular calcification, however, is less clear. METHODS: Smooth muscle cells (SMCs) were isolated from aortas of OPN knock-out (OPN-/-) and wild type (OPN+/+) mice. RESULTS: OPN-/- SMCs were identical to OPN+/+ SMCs in morphology and stained positively for SM lineage proteins, desmin, smooth muscle alpha-actin and SM22alpha. No spontaneous calcification was observed in OPN-/- SMCs under normal culture conditions or in medium containing 1%, 3%, or 5% fetal bovine serum. However, when cultured in medium containing elevated concentrations of inorganic phosphate, an inducer of vascular calcification, a significantly higher calcification was observed in OPN-/- SMCs compared to OPN+/+ SMCs that, in response to elevated phosphate, synthesized and secreted OPN into the culture. Finally, retroviral transduction of mouse OPN cDNA into OPN-/- SMCs rescued the calcification phenotype of the cells. CONCLUSION: These results are the first to demonstrate an inhibitory role of endogenously produced OPN on SMC calcification, suggesting a novel feedback mechanism where OPN produced locally by the SMCs may serve as an important inducible inhibitor of vascular calcification.     

The response of fibrinogen,platelets, endothelial and smooth muscle cells to an electrochemically modified SS316LS surface: Towards the enhanced biocompatibility of coronary stents

Modification of a biomedical-grade stainless steel 316LS surface by electrochemical cyclic potentiodynamic passivation (CPP) and the response of fibrinogen (Fg), platelets, endothelial cells (ECs) and smooth muscles cells (SMCs) to this surface was investigated. Polarization modulation infrared reflection absorption spectroscopy revealed a significant difference between the secondary structure of Fg adsorbed on the unmodified and CPP surface, the latter being closer to that of native Fg. This was postulated as the origin of the significantly lower surface density of attached platelets on the CPP surface. The competitive interaction of ECs and SMCs with the surface showed that the ECs/SMCs surface density ratio is significantly higher on the CPP surface over the first 2 h of attachment, suggesting faster initial attachment kinetics of ECs on the CPP surface. The presented results thus clearly demonstrate an increase in biocompatibility of the CPP 316LS surface.