Immunohistochemistry: a need for standardization

As immunohistochemical techniques continue to evolve, their application to surgical and research pathology is becoming increasingly valuable. Despite this, there is no standard method that can be applied for the analysis of the results of immunostaining to ensure that the selected antibody reacts with the expected antigen specifically. The main goal of standardization in immunohistochemical is to obtain reproducible and consistent results within each laboratory and comparable results among different laboratories. During the technique, specimens are subjected to different preanalytical, analytical and postanalytical variables that may affect the reliability of the stain. Therefore, it is important to highlight the different tissue processing and staining variables that may alter the results of immunohistochemistry and assess the magnitude of reported factors in the literature that require standardization

Effect of bisphenol A on the cauda epididymis of adult male albino rats and the possible protective role of quercetin: a histological and immunohistochemical study

Bisphenol A is a compound released into the environment. It affects male reproductive organs. Quercetin is an antioxidant substance that attenuates various disorders induced by environmental contaminants. To study the effect of bisphenol A on histological structure and immunohistochemical expression of antioxidant glutathione reductase enzyme in cauda epididymis of adult male albino rats, and to evaluate the possible protective effects of quercetin. Fifty adult male albino rats were divided into four groups: control group 1, group 2 receiving bisphenol A, group 3 receiving quercetin, and group 4 receiving bisphenol A and quercetin. After 8 weeks of the experiment, blood was collected for serum testosterone assessment and rats were killed. Cauda epididymis was prepared for histological and immunohistochemical study. Epididymal sperms were obtained to assess sperm concentration and percentage of normal and abnormal sperm forms. Control group 1 showed positive immune reaction of glutathione reductase in cauda epididymis. Group 2 receiving bisphenol A showed structural and ultrastructural degenerative changes in addition to negative immune reaction of glutathione reductase, and a significant decrease in serum testosterone, sperm concentration, and percentage of normal sperm forms associated with a significant increase in the percentage of abnormal forms. Group 3 was not apparently different from group 1 in histological and immunohistochemical reaction. In group 4, quercetin prevented most of changes in cauda epididymis, glutathione reductase, sperms, and testosterone level. Bisphenol A resulted in degenerative changes in cauda epididymis of adult male albino rats. Quercetin prevented most of the changes, suggesting its possible protective effect

Ultrastructural changes in zona fasiculata cells of suprarenal cortex in adult male albino rats after short exposure to high ambient temperature and the effect of fish oil administration

Temperature is one of the stressful factors affecting body systems including zona fasiculata of suprarenal cortex. Investigation of ultrastructural changes in zona fasiculata cells of suprarenal cortex in adult male albino rats after short exposure to high ambient temperature and effect offish oil administration. Thirty adult male albino rats were divided into: Group I control rats, group II rats exposed to high ambient temperature [38°C] 1 hour/day for L one week and group III included rats exposed to high ambient temperature similar to group II and receiving 0.4mg/kg/day fish oil orally, in addition. Animals were sacrificed after one week and suprarenal cortex was prepared for ultra-structural study of zona fasiculata. Compared to group I, rats exposed to high ambient temperature in group II showed significant increase in serum corticosterone and revealed few lipid droplets without discernible outline, dilated smooth endoplasmic reticulum, disrupted cristae of mitochondria and condensed nuclear chromatin in many cells, In group III, rats exposed to high ambient temperature and receiving fish oil showed insignificant increase in serum corticosterone. Many lipid droplets were found and were surrounded with discernible outline. Most of mitochondria were similar to control animals. However, disrupted cristae in few mitochondria were still found. Exposure to high ambient temperature resulted in evident ultrastructural degenerative changes in zona fasiculatacells of adult male albino rats. The administration of fish oil ameliorated such degenerative changes, suggesting a possible favorable effect of fish oil on zona fasiculata cells on exposure to high ambient temperature

Influence of alpha-lipoic acid on streptozotocin induced diabetic cardiomyopathy in adult male albino rats: a biochemical and microscopical study

Cardiovascular disease is responsible for 80% of deaths among diabetic patients. Diabetic patients may suffer from cardiac insult termed 'diabetic cardiomyopathy. Investigation of biochemical structural and ultastructural changes of the diabetic hearts and effect of supplementation with alpha-lipoic acid [ALA]. Thirty adult male albino rats were divided into: group I control rats, group II diabetic rats and group III diabetic rats receiving ALA. Diabetes was induced in rats of groups II and III by streptozotocin drug. The animals were sacrificed after 16 weeks. The hearts and sera were prepared for biochemical and microscopical studies. Diabetic [Group-II] animals showed significant increase in levels of serum; glucose, malondialdehyde [MDA], cholesterol and hepatic glucose -6-phosphatase enzyme [G-6-Pase] activity in addition to a significant decrease in tissue glutathione [GSH]. Structurally, cardiac muscle fibers appeared swollen with areas devoid of fibers, with collagen deposition among them. Ultrastructurally, diabetic hearts showed poorly organized myofibrils and sarcomeres, disrupted Z lines, dilated sarcoplasmic reticulum, abnormal mitochondria with heterogonous electron dense matrix and disrupted mitochondrial membranes. Some mitochondria showed vacuoles and thsion with each other. The wall of blood vessels was irregular. Secondary lysosomes and myelin bodies in between myofibrils were detected. In diabetic [Group-Ill] animals, ALA partially prevented biochemical structural and ultrastructural changes. Different structural, ultrastructural and biochemical changes were evident in diabetic rats after 16 weeks. The supplementation of ALA in diabetic rats partially prevented such changes, suggesting its possible protective effect against the risk of the progression of cardiovascular diseases during diabetes

Immunohistochemical distribution of inducible nitric oxide synthase enzyme [INOS] in the renal cortex of control and diabetic adult male albino rats and the effect of iNOS inhibition by aminoguanidine

Inducible nitric oxide synthase [iNOS] enzyme endogenously synthesizes nitric oxide molecule involved in regulation of renal function. Conflicting reports exist regarding immunohistochemical localization of iNOS in the kidney and its role in diabetes. Investigation of immunohistochemical distribution of iNOS in renal cortex of control and diabetic rats and effect of iNOS inhibition by aminoguanidine. Forty adult albino male rats were used. Rats were divided into; group I [negative control animals], group II positive control rats [receiving aminoguanidine], group III included diabetic rats [diabetes was induced by streptozotocine drug], group IV [diabetic rats receiving aminoguanidine]. The animals were sacrificed afterl month. Kidneys were prepared for histological study and immunohistochemical localization of iNOS in renal cortex. In control [Group I and II] rats, collecting tubules revealed a positive immune reaction of iNOS, while renal glomeruli were negative. Diabetic [Group III] animals showed structural changes 1 month after induction of diabetes in the form of enlarged renal corpuscles, degenerated renal tubules and interstitial leukocytic infiltration, with a positive immune-reaction of iNOS in those structures. In diabetic [Group IV] animals, more diabetic changes were found after iNOS inhibition by aminoguanidine. The iNOS was expressed in collecting tubules of control rat kidney and in renal corpuscles of early diabetic rats. The inhibition of iNOS promoted more diabetic changes, indicating a possible protective role of iNOS against progression of diabetic nephropathy

Microscopic changes in the myocardium of streptozotocin-induced diabetic rats and the effect of vitamin C administration

Diabetic cardiomyopathy can be considered as one of the most common complications of diabetes. Oxidative stress and the production of reactive oxygen species [ROS] were considered to play a key role in the pathogenesis of this cardiomyopathy. Accordingly, this study was planned to detect the biochemical disorders and structural changes in the cardiac muscle in experimentally-induced diabetic rats and to emphasize the role of vitamin C, which could be considered to have an antioxidant effect, in the correction of these abnormalities. Thirty adult male albino rats were classified into three equal groups; group A served as Sham-injected control, while group B rats were turned diabetic by a single intraperitoneal injection of streptozotocin in a dose of 50 mg / kg body weight / rat and left under observation for 16 weeks. The animals of group C were turned diabetic by the same method, but they received vitamin C by stomach tubes for one week before and 16 weeks after induction of diabetes in a single daily dose of 200 mg /kg body weight / rat. Biochemically, significant hyperglycemia and an increase in serum malondialdehyde [MDA] levels with a significant decrease in myocardial glutathione [GSH] were noticed in the animals of group 6 [16 weeks after induction of diabetes]. This was accompanied with extensive microscopic changes in the cardiac muscle in the form of depletion of glycogen content, increased collagen deposition and decreased ATPase activity. Ultrastructurally, myofibrillar disarray in the form of discontinuous, irregular and fragmented Z lines, loss of microfilaments and disorganization of sarcomeres was noticed. The mitochondria appeared irregular in shape with heterogeneous electron dense matrix and disrupted or absent cristae. In addition, appearance of secondary lysosomes and absence of glycogen granules were encountered. The intercalated discs showed a large area having no cellular junctions. These biochemical and morphological abnormalities were apparently reduced in the diabetic rats that received vitamin C. Accordingly, the daily use of vitamin C might play an essential role in the protection against diabetes-induced cardiomyopathy with a more positive impact on management