Nasra N. Ayuob

Cell talk: a phenomenon observed in the keloid scar by immunohistochemical study.

Keloid is a common complication of the wound healing process. Scarce histologic studies describing changes in keloid growth or progression, regarding detailed descriptions of cellular distribution, relationship, or interaction are available. This study aimed to describe the nature, types, and interactions of immune cells (lymphocytes, macrophages, and mast cells), which predominate in keloid complications and may play a role in fibroblastic activation. In this study, 44 samples of keloid were collected, processed, and examined using both light (including routine and immunocytochemical staining) and scanning electron microscopy (SEM). This histologic study showed the characteristic disposition of abnormally thick collagen bundles and newly formed blood vessels in the keloid tissue. The latter showed endothelial hypertrophy, thickened walls with the disposition of homogenous substances, and fibrillar collagen in the perivascular tissue. Numerous mast cells were also observed. Marked cellular infiltration in the perivascular regions and among abnormal collagen was observed. Immunohistochemistry showed the dominance of (CD3) T lymphocytes together with the macrophages (CD68). Among the interesting findings that this study focused on was the cellular interaction. The contact was noticed between the fibroblast and mast cell, the fibroblast and T lymphocyte, the macrophage and both fibroblast and lymphocyte. This cell-cell interaction or contact may explain what was called in literature “cell talk” via cytokines secreted by these cells or through direct gap junctions. In conclusion, cell talk is a phenomenon that was noticed in many pathologic lesions and could explain the mechanism by which different cytokines are secreted by different cells to initiate disease or promote healing.

A model of horizontal and vertical integration of teaching on the cadaveric heart

This work was performed in a trial to organize the learning process by focusing on the integration of medical education particularly between the three main subjects: gross anatomy, histology and pathology. It was a theoretical teaching draft designed to be implemented with second year students of the Medical school of the King Abdul Aziz University, Jeddah, KSA, in order to overcome disadvantages in traditional teaching. The objectives of this work were to make medical students, at the pre-clinical stage of their medical carrier, alert to diagnosis and handling of clinical problems and to develop their ability to integrate pre-clinical and clinical subjects. Fifty human cadaveric hearts were anatomically and histopathologically examined. This examination revealed six different clinical problems such as pericarditis, myocarditis, cardiac hypertrophy, parasitic infestation, rheumatic heart disease and fatty infiltration. The medical students of the second year will be first introduced to the normal anatomical and histological structure of the heart, then allowed to visualize and examine the specimens of the cadaveric heart both macroscopically and microscopically. They will be introduced to a set of clinical problems through some clinical scenarios and asked to search for the possible etiological factors causing these changes, associated signs and symptoms. Finally they will be asked to present their findings and interpretations. This paper demonstrated a pathway of self-directed learning in an integrated teaching setting in the medical curriculum using available cadaveric material at a preparatory stage before developing the system-based curriculum.

Research practices and publication obstacles among interns at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, 2011-2012.

BACKGROUNDnMedical students can play a vital role in health research at any institute. Moreover, scientific publication by medical students is a strong indicator of students knowledge, skills and attitudes towards scientific research. Very little information exists, however, on this matter in Saudi Arabia.nnnSUBJECTS AND METHODSnThis cross-sectional study was conducted to assess the publication practices of medical interns who graduated from King Abdulaziz University Faculty of Medicine and to investigate barriers to conducting and publishing research during their medical studies. A questionnaire was distributed to 394 interns and 249 (63.2%) responded.nnnRESULTSnAbout 31% of the responding interns started research during their undergraduate study years. About 12% discontinued their research, whereas only 7% submitted their research for publication. Only 3.2% of the interns had their research papers published and 3.2% had their research paper accepted for publication; 2% had research papers under revision. Interns had positive attitudes towards research, although only a few of them had submitted their papers for publication. Furthermore, interns expressed the need for training in research design, scientific paper writing and publication practice. They recommended devoting slots in medical school curriculum, in addition to other extracurricular training workshops, to teach and train students on such practices and also to provide more convenient opportunities for student participation in conferences.nnnCONCLUSION AND RECOMMENDATIONSnInterns in King Abdulaziz University Faculty of Medicine have a positive attitude towards research; however, few students submit papers for publication. Lack of time and training in research methods were the main obstacles cited by the interns for conducting and publishing research. Interns welcome training in research, scientific writing and publication practice. These requirements will be issued to the main curriculum committee at the faculty of medicine and recommendations on possible actions will be discussed with the administration.

Impact of medical curriculum on conceptualization of professionalism by residents at a University Hospital, Jeddah, Saudi Arabia.

BACKGROUNDnThe quality of healthcare outcomes and patient satisfaction are affected by communication skills and professionalism of the physician. Medical curricula have substantial influence on physicians perception of professionalism.nnnOBJECTIVESnThe aim of this study was to determine the impact of medical curriculum on the values of the residents at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, and their opinions on professionalism and to identify the sources that they describe as most influential in shaping their views.nnnMETHODSnThis cross sectional study was conducted in 2010/2011. A modified version of the questionnaire designed by Blue and colleagues was distributed among the target group (n=201). Psychometric analysis of the survey tool showed that it was precise and had construct validity.nnnRESULTSnThe return rate was 76.6%. The overall means of the attitudes of both male and female residents toward the attributes of professionalism were low. Attitude toward professionalism showed an insignificant difference between male and female residents. Self-reflection ranked first among all studied attributes. Most male (80%) and female (76.7%) residents believed that working with consultants, specialists, and senior residents in the hospital was the main source of their opinions on professionalism. They considered basic science studies and the other extracurricular courses they attended to be the least helpful in developing their opinions.nnnCONCLUSION AND RECOMMENDATIONSnResidents at King Abdulaziz University Hospital feel underserved in the area of developing their values toward professionalism during the preclinical years, relying to some extent on their experiences during their clinical years and mainly on their interactions with consultants, colleagues, and hospital staff to develop their sense of professionalism. Given the recent changes in the curriculum adopted by the university, it is recommended to assess the attitudes of the students under the new curriculum toward professionalism and to compare them with those of students under the traditional curriculum.

Acute Taxol Toxicity: the Effects on Bone Marrow Mitotic Index and the Histology of Mice Hepatocytes

Abstract Rabah, S.O., Ali, S.S., Alsaggaf, S.M. and Ayuob, N.N. 2010. Acute taxol toxicity: the effects on bone marrow mitotic index and the histology of mice hepatocytes. J. Appl. Anim. Res., 38: 201–207. Hepatotoxic effects of acute intraperitoneal administration of 3 doses; MTD (Maximum tolerated dose) 1.7, ID (Intermediate dose) 1.15 and MD (Medical dose) 0.6 mg/kg Taxol were histologically studied. Mitotic index in hone marrow cells was used to test the drug effect on cell cycle. Vascular congestion, dilation and bile ducts dilatation was observed in liver. Hepatocytes became ballooned and the cytoplasm appeared vacuolated. Apoptotic cells were frequently encountered in all samples. Ultrastructure changes included degeneration of hepatocytes cellular organelles such as endoplasmic reticulum and mitochondria, lipid accumulation and cytoplasmic vacuolation. A significant decrease in mitotic index values in bone marrow cells was observed with higher doses after 24, 48 h. The frequencies of MicroNucleated Polychromatic Erythrocytes (MN-PCEs) were significantly higher in the Taxol treated mice after 24 and 48 h with all doses. This study indicated eneugenic and apoptotic potential of Taxol in mice.

Histological and immunohistochemical study on the possible ameliorating effects of thymoquinone on the salivary glands of rats with experimentally induced hypothyroidism

Background Although the physiological and biochemical effects of hypothyroidism on salivary glands were frequently studied in previous research, its histological aspects have not been sufficiently studied. Aim This study aimed to assess the histopathological changes caused by experimentally induced hypothyroidism in rat salivary glands as well as its effect on the antioxidant status, and assess the possible ameliorating effect of thymoquinone (TQ). Materials and methods Forty adult male Wister rats were randomly divided into four groups (n=10): control group, TQ-treated group, propylthiouracil-induced hypothyroid group, and TQ-treated hypothyroid group. Thyroid hormone levels, thyroid stimulating hormone levels, and antioxidant status were assessed in the blood. The submandibular, parotid, and sublingual salivary glands were processed for histopathological assessment using routine and immunohistochemical assessment of &agr;-smooth muscle actin, epidermal growth factor, caspase-3, and p53 antibodies. Results Salivary gland acini of the hypothyroid rats appeared smaller, and some were atrophied, with significantly increased percentage and number of heterochromatic nuclei and mast cells compared with controls. Increased &agr;-smooth muscle actin and caspase immunoexpression as well as p53-positive cells were evidence of parenchymal injury to the salivary glands. TQ could alleviate these histopathologic changes mostly because of its antioxidant activity as it significantly reduced malondialdehyde, glutathione, and superoxide dismutase activity and significantly increased nitric oxide concentration in hypothyroid rats. Conclusion Propylthiouracil-induced hypothyroidism in rats was associated with histological, biochemical, and immunohistochemical changes in the salivary glands, and TQ can alleviate these changes by improving the antioxidant status of the hypothyroid rats. This calls for further confirmation and validation in applied clinical studies on hypothyroid patients.

Comparative study on the effect of antioxidants α-lipoic acid and N-acetyl cysteine on the structure of the renal tubules of diabetic rabbits

Background and objectives Hyperglycemia-induced oxidative stress plays a central role in the pathogenesis of diabetic complications. The therapeutic potential of antioxidants in the prevention and treatment of these complications is an emerging research area. The roles of &agr;-lipoic acid (ALA) and N-acetyl cysteine (NAC) in the protection against oxidative stress in alloxan-induced diabetic rabbits were assessed both biochemically and histologically in this study. Materials and methods Thirty-two mature male rabbits were used in this study. They were divided into two groups: the control group (n=8) and the experimental (n=24) group; the experimental group was injected intraperitoneally with alloxan (180mg/ml/kg body weight). After 3 weeks, this group (diabetic rabbits) was subdivided into three subgroups of eight rabbits each. The first one was left as the untreated diabetic subgroup; rabbits in the second and third subgroups were treated daily for 7 days with ALA and NAC (100 mg/ml/kg body weight), respectively. At the end of the experiment, blood and kidney sections were processed for biochemical and histological studies. Results The renal tubules showed degenerative and apoptotic changes, which were associated with increased DNA fragmentation and lipid peroxidation in the kidney tissues, as well as reduction in the capacity of the antioxidant defense system. However, treatment of diabetic rabbits with either ALA or NAC ameliorated diabetes-induced oxidative stress. Conclusion ALA and NAC could be useful in the prevention and treatment of oxidative stress associated with hyperglycemia. This action seems to result mainly from direct scavenging of reactive oxygen species and restoring of the GSH (glutathione) redox state.

Can raisins ameliorate hypercholesterolemia-induced nephropathy? What is the evidence?

Background Many drugs that lower circulating cholesterol levels are available, but they are frequently associated with severe side effects. Aim This study was conducted to investigate the possible protective effect of raisins against a high-cholesterol-diet-induced nephropathy using biochemical and histopathological examination. Materials and methods This experimental study was performed on 30 male Wistar rats randomly divided into four groups: group I served as the control group and was fed a standard diet along with saline; group II was fed a standard diet along with 0.5 g of raisins; group III was fed a high-cholesterol diet (HCD); and group IV was fed the HCD along with 0.5 g of raisins through a nasogastric tube for 13 weeks. The kidneys were processed for histopathological examination using light and electron microscopes. The data were analyzed using statistical package for the social sciences (version 16). Results Ingestion of raisins along with the HCD significantly decreased blood glucose, insulin, cholesterol, triglycerides, low-density lipoprotein, and creatinine levels, whereas it increased the high-density lipoprotein level. Mesangial expansion, glomerular capillary congestion, and fibrosis decreased in the rats fed HCD and raisins compared with those fed only the HCD. Raisins significantly reduced mesangial cell activation evident by &agr;-smooth muscle actin, podocyte injury indicated by desmin, and glomerular inflammation denoted by a number of monocytes, whereas it increased endothelial nitric oxide synthase expression in glomerular capillaries. The ultrastructural findings confirmed these results. Conclusion Raisins protect the kidney from hypercholesterolemia-induced injury. Consumption of raisins or its pharmaceutical preparations is advised, particularly for those who consume a high-fat diet.

Amelioration of hypercholesterolemia-induced hepatic changes with red grape juice: A histopathological study.

OBJECTIVESnHypercholesterolemia was confirmed as a risk factor for hepatic fibrosis, as well atherosclerosis and coronary heart disease. This biochemical and histoplathological study was conducted to investigate the possible protective effect of red grape against hepatic injury induced by a high-cholesterol diet (HCD).nnnMATERIAL AND METHODSnThirty male Wister rats were randomly divided into three groups (n=10): the control received saline, the induction group was fed HCD, and the treated group was fed a HCD and 0.4 ml of 100% red grape juice (RGJ) for 13 weeks. After the animals were sacrificed, liver tissue samples were taken to be processed for light and electron microscopy examination.nnnRESULTSnThe administration of the RGJ and HCD significantly decreased the animals blood glucose, insulin, cholesterol, triglycerides, Low Density Lipoprotein levels and increased their High Density Lipoprotein level compared to the rats fed the HCD alone. It also decreased the periportal (macro- and microvesicular) steatosis, fibrosis, lymphocytic infiltration and blood sinusoidal congestion that were observed in HCD-fed rats alone. The RGJ reduced the number of activated myofibrobasts. This was confirmed by a reduction in the expression of alpha smooth muscle actin and desmin. The RGJ increased, although not significantly, the expression of endothelial Nitric Oxide Synthetase.nnnCONCLUSIONnThe administration of RGJ succeeded in alleviating the biochemical and, to some extent, the histopathological changes induced by the high cholesterol diet. Consumption of fresh RGJ or its pharmaceutical preparations is advised especially for those who are used to eat a high fat diet.

Cell cross-talk and interactions: a review of structure and function

Cell–cell interactions are central to the function of many organ systems. The contact between cells and their microenvironment is fundamental both during development and for the preservation of tissue structure. Picking out the signals coming from the surrounding environment enables cells to react promptly to changes that may occur. This work provides a comprehensive review on cell interactions and cross-talk in normal physiological and some pathological conditions of different tissues and organs of the human body (e.g. embryonic, vascular, dendritic, natural killer, cardiac, nerve, lung, testicular, epidermal, and dermal cells). It aimed to explore the nature of this phenomenon and its role in regulating or directing normal cellular function. The mode of cellular interaction was discussed on the basis of biochemical data regarding cytokines or through actual cell contact through different types of junctions or synaptic ribbons. Further understanding of how cell–cell interactions modulate tissue function will allow us to gain fundamental biological insight as well as suggest approaches that will allow the manipulation of tissue function in vitro and for therapeutic applications in vivo.