Macromolecular confinement of therapeutic protein in polymeric particles for controlled release: insulin as a case study

ABSTRACT Sustained release systems for therapeutic proteins have been widely studied targeting to improve the action of these drugs. Molecular entrapping of proteins is particularly challenging due to their conformational instability. We have developed a micro-structured poly-epsilon-caprolactone (PCL) particle system loaded with human insulin using a simple double-emulsion w/o/w method followed by solvent evaporation method. This formulation is comprised by spheric-shaped microparticles with average size of 10 micrometers. In vitro release showed a biphasic behavior such as a rapid release with about 50% of drug delivered within 2 hours and a sustained phase for up to 48 h. The subcutaneous administration of microencapsulated insulin showed a biphasic effect on glycemia in streptozotocin-induced diabetic mice, compatible with short and intermediate-acting behaviors, with first transition peak at about 2 h and the second phase exerting effect for up to 48h after s.c. administration. This study reveals that a simplified double-emulsion system results in biocompatible human-insulin-loaded PCL microparticles that might be used for further development of optimized sustained release formulations of insulin to be used in the restoration of hormonal levels.

Ultrastructural study on biomphalaria alexandrina haemocytes infected with schistosoma mansoni in Egypt and its correlation with nitric oxide level

Some snails of Biomphalaria alexandrina can resist the infection of Schistosoma mansoni so this study aimed to clearly this mechanism by using light and electron microscopy [EM] and determine the role of Nitric oxide in this mechanism. B. alexandrina snails used in this study were exposed individually to S. mansoni infection according to their response they were classified into susceptible group [shed cercariae] and resistant group [failed to shed cercariae]. Snails not exposed to infection were included in this study as control group. Nitric oxide [NO] level was assayed directly in the soluble fraction of B. alexandrina haemolymph supernatants collected from each group of B. alexandrina snails were subjected to NO assay by the Greiss reaction. The level of NO in haemolymph of infected snails was significantly increased [p<0.001] than both control and non infected snails groups, however, in non infected snails group had significantly [p<0.05] compared to control group. This study when correlated the changes recognized by EM with NO level the pro apoptotic effect of high level of NO on the haemocytes. Characterization and identification of cell shape of haemocytes in both haemolymph and tissue were examined by light and electron microscopy. Examination of B. alexandrina snail's haemocytes revealed three types of different cells classified according to their shape and granular contents. These cells are granulocytes, amoe-bocytes and hyalineocytes. Electron microscope Study also revealed the important role of granulocytes and amoebocytes as defense mechanism against snail infection. NO is considered an important anti parasite molecule; intra-molluscan stages of parasites switch off host NO defense response

histological and immunohistochemical study of the effects of leptin on the pars distalis of the pituitary gland in female albino rats

Leptin is an adipocyte-derived hormone. The plasma level of leptin is elevated in obesity and decreased in emaciation. It is involved in the neuroendocrine regulation of pituitary gland function. The present work was carried out to study the histological changes in the pars distalis of the pituitary gland after an injection of leptin in female albino rats. Thirty just-weaned immature female albino rats [22 days] were divided into two groups: group I included 10 animals and served as a control group and group II included 20 animals that received a daily subcutaneous injection of 5 micro g leptin up to the end of the experiment. The females were subjected daily to vaginal smear. After the maturation was established, rats from each group were again subdivided into groups a and b, which were sacrificed 4 and 20 days after puberty, respectively. The pituitary glands were dissected and specimens were prepared for electron microscopic and immunohistochemical assessment. Leptin injection induced various changes in the pars distalis of the pituitary gland. Some cells had deeply stained nuclei and vacuolated cytoplasm. There was a statistically significant increase in the number of positive p53 antibody immunostained cells in the leptin-treated group, especially after 4 days of leptin injection. The most affected cells were somatotrophs, thyrotrophs, and gonadotrophs. They showed features of hyperactivity, with the appearance of some apoptotic cells. Later, necrotic changes such as pyknotic nuclei, ballooned mitochondria with destroyed cristae, and dilated rough endoplasmic reticulum were observed. Prepubertal increase in leptin led to histological changes in some cells of the pars distalis. It is recommended to avoid increase in body weight, especially at a young age

Possible protective effect of Moringa oleifera leaf extract on dexamethasone induced histological changes in adlt rat testes

Dexamethasone [Dex] is a widely used therapeutic agent for its immunosuppressive and anti-inflammatory action. It has adverse effects on many body organs and systems. Moringa oleifera is an antioxidant-rich natural plant. It contains vitamins C and A, and various phenolic compounds. The present study was designed to evaluate the ability of M. oleifera leaf extract to protect rat testis against Dex-induced spermatogenic defects. Thirty adult male rats were divided equally into three groups [10 animals each]: the control group [group I] and two experimental groups [groups II and III]. Rats of group II were subjected to intraperitoneal injection of 7mg/kg/day of Dex for 10 days. In group III the rats were treated with M. oleifera leaf extract at 400mg/kg/day, and then after 2h they were administered an intraperitoneal injection of Dex with the same dose as for group II for 10 days. The testes were dissected out and processed for light and electron microscope examination. Microscopic examination revealed that most of the seminiferous tubules of group II were lined with germ cells with dark pyknotic nuclei and vacuolated cytoplasm. The lumen of some tubules was obliterated with exfoliated and sometimes multinucleated giant cells. There was statistically highly significant increase in the percentage of sperm abnormality. Degenerated interstitial Leydig cells were also observed. However, in the moringa-treated group, the histological changes were reduced and the percentage of sperm abnormality was more or less similar to that of the control group. These results demonstrated that M. oleifera leaf extract has a potent protective effect against the testicular toxicity induced by Dex and hence might be clinically useful

possible protective effect of exercise on liver damage following hind-limb ischemia reperfusion injury in the adult male albino rat: light and electron microscopic study

Hind-limb ischemia-reperfusion [I/R] injury is not limited to the lower extremities; it also causes damage to remote organs. This study was undertaken to investigate the role of exercise in attenuating remote hepatic damage following hind-limb I/R injury. Forty-five adult male rats were divided into three groups: the control group, the I/R group, and the exercise+I/R group. The rats were left to swim for 1 h, five times a week, for 4 weeks before I/R. Bilateral hind-limb ischemia was induced by application of rubber bands above the greater trochanter for 3 h. Blood samples were taken after 3 h of reperfusion for determination of malondialdehyde, superoxide dismutase, tumor necrosis factor-alpha, and interleukin-6. Liver specimens were processed for light and electron microscopic study. In the I/R group, the superoxide dismutase level decreased and plasma levels of malondialdehyde, tumor necrosis factor-alpha, and interleukin-6 significantly increased when compared with the control group. Light microscopic examination showed hepatocytes with vacuolated cytoplasm, dilated blood sinusoids, and portal vessels. An extensive amount of collagen fibers around portal tracts and intense immune reaction for caspase-3 were observed. The ultrastructure showed hepatocytes with swollen mitochondria and disrupted cristae and others with an electron-dense matrix. Kupffer cells showed apoptotic bodies. Ito cells appeared surrounded by wide areas of collagen fibers. The exercise+I/R group showed significant attenuation of the biochemical and histological alterations of I/R-induced liver injury. Exercise could attenuate remote liver damage following hind-limb I/R injury

Ginkgo modulates noise induced hippocampal damage in male albino rats: a light and electron microscopic study

Noise has been a major problem to mankind and induces many auditory and extra-auditory hazards. This study was carried out to determine the injurious effects of noise on the hippocampus and to show whether Ginkgo biloba has any modulatory effect on hippocampal injury. Twenty-five adult male albino rats were divided into five groups: a control group; a noise group exposed to 100 dB of sound pressure level white noise 4h/day for 4 weeks; a protected group exposed to the same noise level with the administration of a G. biloba extract [50mg/kg daily] for 4 weeks; a recovery group, which was allowed to recover for 4 weeks after noise cessation; and a treated group, administered the same dose of G. biloba for 4 weeks after noise cessation. In the noise-exposed group, the pyramidal cell layer of CA1 and CA3 and the granular cell layer of the dentate gyrus [DG] showed a decrease in thickness compared with the control group, which showed loss and degeneration of many cells, and evidence of increased apoptosis. The protected and treated groups showed improvement in many parameters compared with the recovery group, that is, an increase in the thickness of CA1, CA3, and DG; increase in the surface area of cells; increased vascularity; and a statistically significant decrease in apoptosis compared with the recovery group. Noise exerted detrimental effects on cells of CA1, CA3, and DG of the hippocampus. Although partial spontaneous recovery may occur after cessation of noise exposure, the administration of G. biloba led to a marked decrease in the injurious effect of noise on the hippocampus. This might suggest the probable usefulness of G. biloba in reducing the central hazardous effects in individuals exposed to noise

Effect of zinc-free diet from weaning through puberty on the structure of the testis in albino rats, with a special focus on the Leydig cells

Zinc is an essential trace element. Many physiological processes would be impaired if zinc is not supplied in sufficient quantities in the diet. The aim of the work was to evaluate the effect of a zinc-free diet from weaning through puberty on the testicular structure of rats, with a special focus on the Leydig cells. Twenty weaned rats were divided into three groups. Group I [the control group] was fed a balanced diet. Group II [the zinc-free group] was fed a zinc-free diet for 3 months. Group III [the recovery group] was fed a zinc-free diet for 3 months, followed by a balanced diet for 1 month. At the end of the experiment, rats were weighed and blood samples were collected to measure the level of serum testosterone hormone. The testes were removed, weighed, and processed for light and transmission electron microscopic study. The zinc-free group showed a significant decrease in the mean body weight, testis weight, and serum testosterone level compared with the control group. The light and electron microscopic examination showed loss of most of the spermatogenic cells accompanied by variable degrees of degeneration in the form of karryorhexis and haphazard chromatin content. In the interstitial tissue, there was accumulation of exudate. Many Leydig cells showed dilated smooth endoplasmic reticulum and mitochondria. Others cells showed accumulation of glycogen. Most of these changes were reversed after receiving the balanced diet in the recovery group. A zinc-free diet altered the structure of both the seminiferous tubules and the Leydig cells. Most of these alterations were reversed by zinc replenishment. Zinc is considered an essential element for maintaining testicular structure and spermatogenesis process

Histological characteristics of botulinum neurotoxin-A on rat skeletal muscles

Botulinum neurotoxins-A [BT-A] are bacterial enzymes that block neurotransmitter release. BT-A is widely used to treat spasticity and dystonias, and also in pharmacocosmetic and in the management of various types of pain. It is therefore important to clarify the histological characteristics involved in muscular tissue postinjection and to reconcile its injection for cosmoses under scope. Fifteen adult albino rats were used in this study and divided into three groups [five rats each]. Group I served as negative control; groups II and III were injected into the right gastrocnemius muscle with BT-A in addition to saline into the left side to serve as positive control. Muscle harvest was examined by LM, EM, and morphometry at 28th day for group II with two rats of group I and at 56th day for group III with three rats of group I. Histological examination revealed neurogenic atrophy, target fiber change, hypertrophied fibers, and dilated aggregates of the sarcotubular system. Neurogenic muscle atrophy following a single BT-A injection should be taken into consideration when repeated BT-A injections into the same muscle are needed

Light and electron microscopic study of thyroid follicular cells in adult albino rats following green tea administration

Green tea [GT] is one of the most popular beverages with high daily consumption worldwide. It has a rich content of polyphenols, among which catechins predominate. Its extracts are widely used as ingredients in dietary supplements, beverages, and functional foods, which may lead to a higher consumption of GT polyphenols by the general population. Recently, a relationship between GT administration and disruption of thyroid homeostasis was suggested. The goal of the study was to clarify the impact of GT administration on the histological structure of thyroid follicular cells of adult albino rats. Thirty adult male albino rats [140-160 g] were categorized into three equal groups: group I served as the control group; groups II and III received 1.25 and 5.0 g% GT extract orally at a dose of 10 ml/kg body weight, respectively, every day for 30 days. At the end of the experiment, blood samples were collected from all animals for estimation of serum triiodothyronine [T[3]], thyroxine [T[4]], and thyroid stimulating hormone. Rats were then euthanized and the thyroid glands were harvested for histological examination of thyroid follicular cells by light and transmission electron microscopy. The follicular epithelial height and colloid area of thyroid follicles were morphometrically evaluated and statistically analyzed. GT in small concentrations [in group II] did not induce any significant change in hormonal, histological, and histomorphometric assessments as compared with the control group. However, some follicular cells exhibited mildly dilated rough endoplasmic reticulum and multiple lysosomes. In contrast, GT administration in group III induced hypothyroidism as evidenced by significant reduction in serum T[3] and T[4] levels along with substantial increase in thyroid stimulating hormone level compared with controls. Histologically, many follicles displayed signs of hyperactivity as evidenced by focal hypertrophy and hyperplasia of the follicular cells along with colloid depletion. Ultrastructurally, dilated rough endoplasmic reticulum and disrupted mitochondria were encountered. Some severely degenerated follicular cells were revealed as well. Histomorphometrically, there was a significant increase in the mean follicular epithelial height, whereas the colloid area was significantly lowered as compared with the respective controls. The study clearly indicates that GT in large concentrations has the potential to disrupt thyroid follicular cell structure and function

Protective effect of orange and grapefruit peel extracts against testicular toxicity induced by sulfasalazine in male albino rats

Sulfasalazine is a drug commonly used for the treatment of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. However, the histological changes in the testes are not well defined. Also, orange and grapefruit peels are powerful antioxidants that have come into use recently for the treatment of infertility. This study aimed to elucidate the histological, immunohistochemical, and ultrastructural changes in the testes after sulfasalazine treatment and evaluate the possible protective role of orange and grapefruit peel extracts. This study included 48 adult male albino rats divided into six equal groups: the control group [group I]; the orange peel extract group [group II]; the grapefruit peel extract group [group III]; the sulfasalazine group [group IV]; the sulfasalazine and orange peel extract group [group V]; and the sulfasalazine and grapefruit peel extract group [group VI]. At the end of the experiment [2 weeks], all animals were sacrificed and their testes were excised. Paraffin sections were prepared and stained with H and E and immunohistochemical staining was performed for proliferating cell nuclear antigen. Other pieces of the testis were used for ultrastructural study. Sulfasalazine was shown to affect the testes. The changes were in the form of irregular degenerated seminiferous tubules, germ cells, decrease in proliferating cell nuclear antigen, ultrastructural alterations of spermatogenic cells, and thickened basement membranes. These changes were present in some tubules in the testes. Treatment with orange or grapefruit peel extracts proved to improve these changes. Sulfasalazine has deleterious effects on the structure of the testes and supplementation with orange or grapefruit peel extracts with sulfasalazine can overcome the toxicity of sulfasalazine on the testis and protect testicular tissue from the detrimental effects of sulfasalazine

Assessment of the protective role of vitamine E in atrazine toxicity on the testis of adult albino rats: a histological and biochemical study

Atrazine [ATZ] is one of the most commonly used herbicides that adversely affect the reproductive system in rats. The aim of the study was to evaluate the impact of vitamin E [Vit E] on subchronic exposure to ATZ in testicular tissue. Fifty adult male albino rats were divided into five groups: the negative control group; the positive control group, which received 1 ml of corn oil/day, orally; the Vit E group, which received Vit E at 100 mg/kg/day, orally; the ATZ group, which received ATZ at 300 mg/kg/day, orally; and the ATZ+Vit E group, which received both ATZ and Vit E at the previously mentioned doses. Treatments were given for 6 days/week for 45 days. At the end of the experiment, blood samples were taken to measure serum testosterone level. Semen analysis and estimation of oxidative stress markers catalase, superoxide dismutase, and tissue malondialdehyde were carried out. The testes were processed for light and electron microscopic examination. An immunohistochemical study was performed for detection of Bcl2. ATZ caused a decrease in serum testosterone level and in superoxide dismutase and catalase enzyme activities, whereas malondialdehyde content increased. There was also a decrease in sperm count, viability, and motility in comparison with the control groups. Light microscopic examination of seminiferous tubules revealed degeneration of the germinal epithelium. The lumen contained sloughed cells and homogenous acidophilic material. Ultrastructurally, there was separation of the germinal epithelial cells with small dense nuclei and phagocytic remnants. Sertoli and Leydig cells were also affected. Bcl-2 immunolocalization revealed weak reaction in the cytoplasm of the germinal epithelial cells and Leydig cells. Concomitant use of Vit E caused partial improvement. ATZ induced detrimental effects in the testicular tissue that were attenuated by concomitant administration of vitamin E

Effect of malathion on pars distalis of the pituitary gland and the possible protective role of vitamin C in adult female albino rats: a histological, immunohistochemical, and ultrastructural study

Malathion is one of the organophosphorus insecticides that are widely used in agriculture and have been reported to cause multiple organ damage. Vitamin C has been proposed as an antioxidant because it reduces oxidative stress. This work aimed to study the possible histological, immunohistochemical, and ultrastructural changes of gonadotrophs and somatotrophs of the pars distalis of the anterior pituitary gland associated with chronic sublethal malathion administration and assess the possible beneficial role of vitamin C in ameliorating these possible changes. Forty adult female albino rats were divided into four groups. Group I served as the control group. Group II received vitamin C at a dose of 20 mg/100 g/day. Group III animals were treated with malathion at a dose of 100 mg/kg/day. Groups IV animals received vitamin C and then malathion after 2 h at the previous doses. The treatments were given orally to the rats for 2 months. The rats were then sacrificed and specimens from the anterior pituitary gland were taken for light and electron microscopic examination. Light microscopic examination of rats treated with malathion revealed that gonadotrophs exhibited vacuolated degranulated cytoplasm and pyknotic nuclei, whereas somatotrophs appeared shrunken with dense nuclei. Immunohistochemically, there was a decrease in the immunoreactivity of follicle stimulating hormone, luteinizing hormone, and growth hormone-secreting cells. Ultrastructurally, gonadotrophs and somatotrophs showed disintegration of cellular organelles and apoptosis of the nuclei. Coadministration of malathion with vitamin C showed a slight improvement in some gonadotrophs and somatotrophs that looked normal in both light microscopic and electron microscopic examination; however, still others were markedly affected, showing signs of degeneration and apoptosis. The results showed that malathion in chronic doses induces histological, immunohistochemical, and ultrastructural changes in gonadotrophs and somatotrophs because of oxidative stress, and the use of vitamin C partially improves the malathion-induced toxicity

Differential expression of alpha-smooth muscle actin and vascular endothelial growth factor in skin biopsy of patients with systemic sclerosis: a histological and immunohistochemical study

Vasculopathy is a hallmark of systemic sclerosis [SSc]. It contributes to many of its clinical manifestations and precedes fibrosis. The aim of this study was to investigate the expression of alpha-smooth muscle actin [alpha-SMA] in skin biopsy of patients with SSc and correlate it with other manifestations of vasculopathy, including those seen on fundus fluorescein angiography and tissue vascular endothelial growth factor [VEGF] expression. This study included 25 patients with SSc and 10 healthy individuals. Patients underwent full history taking and a clinical examination. All participants underwent fundus fluorescein angiography. Skin biopsy was examined by H and E staining, Mallory triple staining, and immunohistochemical staining for alpha-SMA and VEGF. Histological examination showed loss of dermal papillae, hypovascularity of the dermis, and subepidermal fibrosis. Immunohistochemical staining of the vessel wall in skin biopsy samples showed a statistically highly significant increase in VEGF and a highly significant decrease in alpha-SMA in patients as compared with controls. There was a highly significant positive correlation between VEGF and duration of illness, Raynaud's phenomenon, digital ulcers, disease activity score, and modified Rodnan Skin Score. As regards alpha-SMA, there was a highly significant negative correlation with Raynaud's phenomenon, disease activity score, modified Rodnan Skin Score, and VEGF, whereas there was a significant negative correlation with digital ulcers. The strongest correlation [r] for the duration of illness was found with alpha-SMA, followed by VEGF. alpha-SMA was found to be correlated to different manifestations of vasculopathy in SSc. It was found to be one of the early markers of vasculopathy among the other studied variables. Besides its diagnostic role in SSc vasculopathy, it could play a role in impaired vasculogenesis, making it a potential therapeutic target in the management of SSc

Immunohistochemical and light and electron microscopic study of the basement membrane in photoaged skin

The basement membrane plays an important role in maintaining a healthy epidermis and dermis, and repeated damage destabilizes the skin and accelerates the aging process. This study was carried out to detect the changes in human skin basement membrane in sun-exposed skin compared with sun-protected skin. Skin biopsies were taken from sun-exposed and sun-protected skin of 10 male individuals aged between 50 and 60 years and processed for light and electron microscopic examination of the changes of the basement membrane. Immunohistochemical assessment of laminin and matrix metalloproteinase-1 [MMP-1] expression in skin biopsies was also carried out. Histological examination of sections of sun-exposed skin revealed that the basement membrane was discontinuous and the collagenous fibers of the underlying connective tissue were discrete in comparison with sun-protected skin. Immunoreactivity for laminin was decreased, whereas that for MMP-1 was markedly increased in sun-exposed skin as compared with sun-protected skin. The results of the current study revealed that the structure of the basement membrane was affected in sun-exposed skin as regards thickness, continuity, and structure. Increased activity of MMP-1 accounts at least in part for the disruption of the basal lamina and degradation of collagenous fibers of the dermis

Role of losartan on the renal cortex damage induced by cisplatin in adult male albino rats

Cisplatin is a potent anticancer agent for the treatment of solid tumors, but its use is limited by its adverse effects. This research aimed to evaluate the effect of losartan on cisplatin nephrotoxicity in adult male albino rats. Twenty-five male albino rats were divided into four groups. The first was the control group. Group II received a single injection of cisplatin. Group III received losartan for 6 days. Group IV received a single injection of cisplatin in addition to losartan ingestion for 6 days. Renal tissues were prepared for light and transmission electron microscopic examinations. Glomerular diameter and cell number were measured by means of an image analyzer. Also, glomerular capillary basement membrane [GBM] thickness, filtration slit width, and pedicel length were recorded and statistically analyzed. The renal cortical sections of group II rats showed loss of normal appearance of renal corpuscles with enlarged glomeruli and increased glomerular cellularity. Degenerative changes and necrosis of the lining cells of proximal convoluted tubule were noted. Intertubular hemorrhage and cellular infiltration were detected. Electron microscopic examination revealed fusion of the foot processes with significant increase in the thickness of GBM and filtration slit width. Damage of proximal convoluted tubule cells was seen more than damage of distal convoluted tubules. The renal cortical sections of group III rats showed vacuolated cytoplasm of some tubules lining cells. Electron microscopic examination revealed some ultrastructural changes in the distal convoluted tubule lining cells. Most of the renal corpuscles of rats treated with losartan and cisplatin appeared normal, with presence of some enlarged corpuscles as well as cytoplasmic vacuolation of the tubular cells. Electron microscopic examination revealed a significant decrease in GBM thickness and filtration slit width in comparison with cisplatin-received rats. From this study, it was obvious that losartan ameliorates the histological changes induced by cisplatin given at a dose of 3 mg/kg in adult male rats

Effect of partial bladder outlet obstruction on the histological structure of adult male rat urinary bladder and the role of L-arginine supplementation

Bladder outlet obstruction [BOO] is one of the most common urological problems in elderly men. l-Arginine, a precursor of nitric oxide synthesis, is thought to play an important role in the lower urinary tract function. The aim of this study was to verify the effect of partial BOO on the structure of the urinary bladder in adult male albino rats and to test the possible protective role of l-arginine. Twenty-seven adult male albino rats were divided into three groups: rats in group I served as controls. Rats in group II were subjected to partial BOO. In group III, the obstructed rats were injected intraperitoneally with L-arginine [at a dose of 150 mg/kg body weight/day] for 6 weeks. Specimens were processed for H and E and Mallory trichrome stains, desmin immunoreaction, and electron microscopic study. Morphometric results were statistically analyzed. Examination of the urinary bladder of obstructed rats showed an observable reduction in the urothelium thickness with focal sloughing of the mucosa as well as cytoplasmic vacuolation of some cells. Cellular infiltration and dilated congested blood vessels of the lamina propria were also encountered. Most smooth muscle cells were distorted with wide separation of muscle bundles and significant increase in the optical density of desmin expression. An increase in collagen fiber deposition was detected in the lamina propria. Ultrastructurally, the superficial urothelial cells showed electron-lucent vacuoles and large electron-dense granules, whereas the myocytes had irregular sarcolemmae. L-Arginine was able to prevent most of the observed alterations. L-Arginine showed a potential protective role against the altered urinary bladder structure induced by partial outlet obstruction. Further physiological studies on the detrusor muscle under the effect of l-arginine are recommended

Histological study on the effect of metformin on high-fat-diet-induced liver injury in adult male albino rats

Changes in lifestyle and food habits increase the prevalence of nonalcoholic fatty liver disease [NAFLD]. It is a chronic condition that has no or few symptoms. It may be accompanied by inflammation and insulin resistance. Moreover, it is closely linked to diabetes. Metformin is an antidiabetic agent that can improve insulin resistance. The study was conducted to investigate the effect of metformin on liver injury induced by a high-fat diet. The study lasted for 12 weeks. Thirty-six adult male albino rats were used and divided into four groups. Group I was the control group. Group II rats received metformin. Group III rats were fed a high-fat diet for induction of NAFLD. Group IV rats were fed a high-fat diet for induction of NAFLD and then administered metformin orally in the last 4 weeks of the study. Liver specimens were processed for light and electron microscopic examination. Moreover, liver weight index was determined, and biochemical, morphometric, and statistical studies were performed. Induction of NAFLD [group III] resulted in severe insulin resistance. Hepatocytes showed macrovesicular and microvesicular steatosis, ballooning, and lobular inflammation. The number of positive cells and the reaction for tumor necrosis factor-alpha in group III apparently increased as compared with group IV. Lipid droplets, loss of mitochondrial cristae, and dispersion of rER were detected in group III. Metformin improved insulin resistance, and liver histological changes were fewer than those in group III. Metformin can greatly improve liver histological changes associated with a model of NAFLD

Effect of aqueous extract of Hibiscus sabdariffa on hyperthyroidism-induced changes in the renal cortex of rats: a histological study

Hyperthyroidism is a condition resulting from hypersecretion of thyroid hormones [T3 and T4]. It affects multiple organ systems, including the renal system. This study was set to evaluate the protective effect of Hibiscus sabdariffa [roselle] on the damaging effect induced by hyperthyroid state in the rat renal cortex. Twenty-four adult male albino rats were used and divided into four groups of six rats each. Group I was the control group. In group II, the rats received aqueous extracts of roselle at a daily dose of 500 mg/kg body weight. In group III, the rats were given a daily oral dose of thyroxin [100 micro g/kg body weight] dissolved in distilled water through gavage for 1 month. In group IV, the rats were given an aqueous extract of roselle at a daily dose of 500 mg/kg body weight 3 h before thyroxin administration at 100 micro g/kg body weight. At the end of the experimental period, blood samples wer collected for thyroid hormone [T3 and T4] assay. Kidney specimens were processed for immunohistochemical and histological study using light and electron microscopes. Morphometric analysis of the proximal convoluted tubule [PCT] diameter was carried out. A statistically significant elevation in the levels of T3 and T4 was observed in the thyroxin-treated group. Also, a significant increase in the diameter of PCT was detected in this group. Histologically, some malpighian corpuscles were partially atrophied. Effacement of podocyte foot processes with thickening of the filtration barrier was observed. In addition, tubulointerstitial injury in the form of PCT dilatation, peritubular hemorrhage, and inflammatory cellular infiltration was also seen. Immunohistochemical examination of the thyroxin-treated group revealed excess actin fibers in the PCT cells, indicating exposure of these cells to stress. Furthermore, there was significant improvement in the histological and immunohistochemical pictures toward normal in the thyroxin and roselle-treated group. Roselle has a potent protective effect against the damaging effect induced by the hyperthyroid state in the rat renal cortex

Effect of unilateral hind limb immobilization on ipsilateral soleus muscle morphology of adult male albino rats

Clinically, limb immobilization has been extensively used during recovery of musculoskeletal injuries despite the fact that this technique causes functional deficits in the skeletal muscle. This work aimed to study the morphology of ipsilateral soleus muscle after left hindlimb immobilization in the shortened position in adult male albino rats. Ten healthy adult male albino rats were divided equally into two groups: a control group and an immobilized group. Immobilized animals were anesthetized and their left hindlimbs were fixed for 2 weeks keeping the soleus muscle in the shortened position. Animals of the control group were anesthetized without carrying out any procedures for soleus muscle fixation and then were kept freely moving in their cages for the same period. Left soleus muscles of all animals were dissected out and processed for examination by light and electron microscopy. Immunoreaction experiments for desmin were carried out. The left soleus muscles of immobilized rats showed that most of the muscle fibers were shrunken with widened endomysium, deeply stained nuclei, and lighter-stained foci. The affected myocytes contained distorted Z-lines, thinning or focally destroyed myofibrils, loss of myofilaments, and undulating sarcolemmae. Sarcosomes were bizarre shaped, amorphous, and giant. Desmin immunoreactivity appeared weak. Immobilization led to muscle fiber structural alterations in the form of thinning or focally destroyed myofibrils, loss of myofilaments, Z-line distortion, and disorganized desmin distribution. These changes can produce muscle fiber weakness, which consequently affects motor performance

Ultrastructural study on microfold cells and microvillus cells in the follicle-associated epithelium over Peyer's Patches in albino rat

Microfold cells [M cells] act as gateways to the mucosal immune system. The aim of the study was to perform a detailed ultrastructural study on M cells and microvillus enterocytes in the follicle-associated epithelium that covers the dome region of the ileal Peyer's patches in the albino rat to understand the relationship between the two types of cells, the origin of M cells, and their possible mechanism in sampling of the luminal antigens. The follicle-associated epithelium over the Peyer's patches in 10 adult albino rats was studied carefully under transmission electron microscope with a special attention to M cells and microvillus enterocytes. M cells were characterized by pale cytoplasm and either paucity or lack of apical microvilli beside intracytoplasmic pockets harboring migrating lymphocytes. In the microvilli-lacking areas, however, bundles of microvillus filaments occasionally remained in the apical cytoplasm and small vesicles and tubules were found at the apical poles of M cells. Microvillus cells had apical brush borders composed of long, regular, and densely packed microvilli; however, a wide range of diversity of the apical surface morphology was noted. Sometimes, transitional epithelial cells from microvillus to M cells were observed as columnar cells, which had microvilli of moderate height in their apical border with appearance of bare areas, in addition to other cells, which had a microfolded profile that bore few stout and short microvilli. Pale cytoplasmic extensions of dendritic morphology were seen extending among the epithelial cells covering the Peyer's patches. The M cells were differentiated from the intestinal enterocytes by distinctive ultrastructural features. The observed transitional epithelial cells might indicate that the M cells probably originated from the microvillus enterocytes. The M cells transport the antigens from the intestinal lumen to the lymphocytes in the intraepithelial pockets for induction of mucosal-associated immune response