Journal of Microscopy and Ultrastructure

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In a VMS ore at Al Amar gold mine (level 640 FW-E), sulfide minerals are paragenetically ordered as follows: pyrite(I)–sphalerite–chalcopyrite–galena–pyrite(II), deformations vary from brittle to ductile deformation fabrics. Microscopically, the massive sulfides have pyrite porphyoblasts (up to ~80%) that show evidence of creep dislocation as a result of low-temperature plastic deformation rather than brittle failure, whereas high-temperature annealment is completely lacking. Softer minerals such as chalcopyrite fill into fractures in pyrite as narrow slivers. Needle-shaped or lamellar morphology of chalcopyrite, together with the chemical composition of Fe-poor sphalerite (with maximum 0.99 wt% Fe) suggest a combined replacement–coprecipitation mechanism of chalcopyrite disease formation rather than an exsolution texture. Greenschist facies metamorphism produces an ore with distinct chalcopyrite disease into a stratified ore with microbands of chalcopyrite and sphalerite. Ore microfabrics and uncommon occurrence of epithermal stringers suggest noticeable effect of the Najd tectonics in the studied level. The EMPA analyses indicate that all sulfide minerals in the VMS ore are auriferous and the Au contents are considerable (up to 0.94, 1.31, 0.16 and 1.20wt%; in sphalerite, chalcopyrite, galena and pyrite, respectively). Gold in pyrite is “invisible” whereas it occurs as submicroscopic inclusions in sphalerite, chalcopyrite and galena. The VMS ore of Al Amar deep horizons are characterized by the occurrence of “invisible gold”, Ag-free galena, Fe- and Ni-poor sphalerite, negligible hydrothermal alteration, plastic deformation of pyrite and non-exsolution origin of the chalcopyrite disease intergrowth which are together strong indicators of low-temperature (250–300°C).

Engine oil is an important and the most essential part of machine system. Oil monitoring is a tool to determine lubricant useful life. It can be either performance testing or oil condition monitoring. Knowledge of the system's failure modes is essential for cost-effective oil monitoring. Contamination occurs by mating contact inside the engine chamber. In the present work used CH₄15W40 engine oil were monitored under bichromatic microscope to observe the contamination and surfaces wear micrograph. According to the observation, rubbing, cutting, fatigue, corrosion, abrasive and scuffing wear modes were observed.

Since its introduction, conventional endoscopy has changed the management framework of a variety of gastrointestinal tract (GIT) diseases and is now considered a fundamental component in the evaluation and treatment of gastrointestinal diseases. Histologic analysis of specimens remains the gold standard for the final diagnosis of gastrointestinal lesions. However, such workup is time-consuming and labor-intensive. This restricts the endoscopists to immediately determine the necessity for resection during ongoing endoscopies, necessitating the need to repeat the procedure. Furthermore, overtreatment (resection of benign lesions) or undertreatment (biopsy instead of resection for neoplastic tissue) can lead to frustrations, unnecessary risks (e.g., bleeding) for the patients, and delay in definite treatment for the urgent cases. Recently, developments in endoscopic and imaging technologies (narrow-band imaging, autofluorescence imaging, confocal laser endoscopy and imaging, optical coherence tomography, and endoscopic ultrasound) can provide a wide variety of valuable tools for in vivo cytological diagnosis of neoplastic lesions of GIT, even beyond inner layer of the bowel. Such investigations, may therefore lead to an optimized rapid diagnosis of GIT lesions, providing important implications also for immediate therapy, during ongoing endoscopies (e.g., endoscopic resection of neoplastic tissue). Moreover the possibility to properly investigate in vivo progression of the extraluminal disease (lymph node status) allows reducing, if not eliminating the need of extensive resection just for proper staging. The present review convincingly describes the operating systems of each diagnostic modality, their clinical implications, and future vision of the role of these modern tools in the clinical diagnosis of GIT diseases.

Skin tags (ST) are the most common fibro-epithelial skin tumors. They are tumors of the middle-aged and elderly people. However, in women, the age of 50 is suggested to be the turning point of life at which the development of skin tags comes to a stop. A major event that occurs around this period of life is menopause/andropause, after menopause, estrogen receptors amounts decrease significantly. Estrogen receptors (ER) and androgen receptors (AR) are members of the steroid receptor gene superfamily. Estrogen receptors positivity has been demonstrated in most skin tumors by both histochemical and biochemical assays. This study aimed to assess the role of estrogen and androgen receptors in the development of skin tags by assessment of their immunohistochemical expression. Twenty five patients were included in this study. Snip excision of skin tags was done for each patient, punch biopsy from adjacent sites from skin tags have been taken as perilesional skin biopsy only for twelve patients. Histopathology was performed to confirm the diagnosis. Immuno-histochemical staining was done to detect ER and AR for skin tags, perilesional skin, and control normal skin. Immunohistochemical staining for ER was positive in 64% of skin tag cases and AR were positive in 60% of them. There was a statistically significant difference in ER and AR staining pattern between skin tags, perilesional skin and normal skin. It could be concluded that ST correlated positively with ER and AR immunohistochemical staining which may implicate a role for them in the pathogenesis of skin tags.

Information on potential genetic damage in humans after exposure to waste anaesthetic gases in Egyptian hospitals is scarce. To evaluate the possible genotoxic effects of waste anaesthetic gases, the chromosomal aberrations [CA] and the sister chromatid exchange [SCE] tests, were studied in peripheral blood lymphocytes in 26 operating room personnel (exposed group) currently employed at Tanta University hospitals, in comparison to a group of 13 non-exposed persons (control group), matched by age, sex and smoking habits. The results showed a statistically significant increase in chromosomal aberrations and sister chromatid exchange in the exposed persons in comparison to controls. Also it suggests that exposure to waste anaesthetic gases has the potential to cause changes in human genome.

Microvillus inclusion disease (MVID) is a rare autosomal recessive disorder due to defective apical surface of the enterocytes presenting with protracted diarrhea from birth. The aim of the study is to describe the pattern of MVID in pediatric population of King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. This retrospective cohort study used small intestinal biopsies submitted to the histopathology laboratory of KAUH between January 2002 and December 2011 from infants aged 0–24 months with intractable diarrhea. Histological slides and pathology reports were reviewed. PAS and CD10 were performed if not available along with electron microscopic examination of the cases and review of the patients’ medical charts. Four (10.5%) cases of MVID were found among 38 small intestinal biopsies submitted to the laboratory with the above mentioned criteria. Two (50%) were females. The four presented with intractable diarrhea during their first week of life that required support with parenteral nutrition. All have died of their disease in their infancy. Light microscopy of their small bowel biopsies showed moderate to severe villous atrophy in all of the four cases. PAS and CD10 immunostain showed loss of the sharp staining of the brush border. Ultrastructural examination of the intestinal epithelial lining demonstrated atrophic surface microvilli in the apical portion of the enterocyte cytoplasm characteristic microvillus inclusions. In conclusion, MVID is a rare fatal disorder with no sex predilection. Clinicians and pathologists should consider it in the differential diagnosis of infants presenting with chronic intractable diarrhea.

Online since 21^st December 2017