effects of ultraviolet B [UV-B] radiation on albino rat cornea and epitheial cells

To evaluate the influence of UV-B radiation on the cornea and epithelial cells of the albino rat. 100 Sprague-Dawely rats were divided in 4 groups with different ages [3, 6, 10, 18 weeks] and control one. Exposed 4 groups were irradiated to UVB with wave length 300nm and intensity of 8 kj/m2. Each group was divided into 2 sub-groups [A and B] according to the time of exposure [15 and 30 minutes]. The control group [C] was divided into 5 rats for each group. One week after exposure cornea was removed to evaluate the histopathological changes. Groups were compared by evaluating the difference between exposed and non-exposed cornea. Exposure to 15 minutes UV-B showed degenerative changes in all ages and increased with time of exposure. Epithelial hyperplasia was 25% in 6 weeks group exposed to 15 minutes of UV-B and 33.3% with 30 minutes of exposure. In 18 weeks group hyperplasia was 25% after 30 minutes of exposure. Epithelial thinning was detected only in 3 and 18 weeks groups after exposure to 30 minutes of UV-B by 33.3%. Epithelial erosion was 16.6% in 10 weeks group after 30 minutes of exposure. Stromal blood vessels were detected in exposed groups to 30 minutes of radiation in 6, 10 weeks by 16.6% and 41.6%. Stromal edema was detected in all ages exposed to 15 and 30 minutes of UV-B. Exposure to UV-B comeal epithelial and stromal changes which increase with time of exposure

effects of ultraviolet B [UV-B] radiation on the lens in albino rats in different ages and times of exposure

To investigate the effects of UVB radiation on the crystalline lens of the rat lens. 100 Sprague-Dawely rats were divided in 4 groups with different ages [3, 6, 10 and 18 weeks] and control one [20 rats in each group]. Exposed 4 groups were irradiated to UVB with wave length 300nm and intensity of 8kj/m2. Each group was divided into 2 subgroups [A and B] according to the time of exposure [15 and 30 minutes]. The control group [C] was divided into 5 rats for each group. One week after exposure, both lenses were removed for morphological changes and for histopathology. Groups were compared by evaluating the difference between exposed and non-exposed lenses. Early cortical cataract [vacuoles] was not detected in all [B] groups, and appeared in all [A] groups As except E4 group. Cortical cataract appeared in both exposed groups and the increased with age. Equatorial cataract was detected in all ages and the incidence increased in rats of [A] groups. Sutural cataract was more in young groups and the incidence increased with time of exposure to UV-B it was not detected in E4 group. Early nuclear and nuclear cataract was more in young ages and increased time of exposure. UV-B has powerful effects on the rat lens and development of different types of cataract, which differs according to the age and time of exposure. The more exposure to UV-B the more the cataract develops

Assessment the effectiveness of hematopoietic growth factors on hepatic regeneration after partial hepatectomy in albino rats with induced bone marrow suppression

This study aimed to evaluate the effect of hematopoietic growth factors [erythropoietin and granulocyte colony stimulating factor] on liver regeneration after partial hepatectomy and bone marrow suppression of rats and to investigate the role of hematopoietic stem cells in liver regeneration by assessment of CD 34+ hematopoietic stem cells marker in hepatic tissues. 36 adult male albino rats were used in this study and were divided into six groups each of 6 rats: the 1st is the control group, the 2nd is bone marrow suppression group, 3rd is subjected to partial hepatectomy, 4th is subjected to bone marrow suppression by benzene, then 70% partial hepatectomy, 5th is subjected to 70% partial hepatectomy with injection of Eprex and Neupogen at time of partial hepatectomy, then daily for 5 days post hepatectomy and the 6th group is subjected to bone marrow suppression by benzene first then 70% partial hepatectomy with injection of Eprex and Neupogen daily for 5 days post hepatectomy. Histological evaluation and immunohistochemical study for CD34+ cells in the hepatic tissues were assessed. There were no regenerative changes in both control and benzene treated groups. There were little regenerative changes in the group of partial hepatectomy after benzene treatment but in the groups that were treated with the hematopoietic growth factors. These regenerative changes were increased especially in the treated group after partial hepatectomy than treated group after partial hepatectomy and bone marrow suppression. Immunostaining of CD34 expression as marker of HSCs in liver sections showed the following; the normal group, benzene treated group and partially hepatectomized group after benzene treatment showed no expression, but partially hepatectomized group show focally positive expression. Both groups treated with hematopoietic growth factors either after partial hepatectomy or after partial hepatectomy and bone marrow suppression by benzene show diffusely positive expression. The present study had shown that Erythropoietin and Granulocyte colony stimulating factors stimulate regenerative process occurred in the liver after partial hepatectomy only and after partial hepatectomy with bone marrow suppression either by endogenous mechanisms or by mobilization of hematopoietic stem cells

Assessment of hepatic regeneration after partial hepatectomy in albino rats with induced bone barrow suppression

The liver has a remarkable capacity to regenerate after injury. Within a week after partial hepatectomy [PH] hepatic mass is back essentially to what it was prior to surgery. Hematopoietic stem cells [HSCs] may contribute in the regeneration and the renewal capacity of hepatocytes. To investigate the origin of hepatocytes in liver regeneration whether from resident hepatic stem cells or from circulated HSCs after suppression of HSCs from bone marrow by Benzene This experimental study included 24 adult male albino rats. The studied animals were divided into 4 groups; first group [control group] was included 6 normal rats. No intervention was carried out to this group of rates. Second group [PH] group] was included 6 rats in which 70% PH was done. Third group [Benzene group] was included 6 rats of in which bone marrow [BM] suppression was carried out by Benzene injection. Ten injections were performed subcutaneously in a period of 3 weeks for induction of BM suppression. Fourth group [Benzene+ PH group] was included 6 rats in which BM suppression was carried out as 3rd group. Seventy percent PH was then done to them. Cytological changes during regeneration were assessed in all groups by; the number of binucleate cells and the restored number of hepatocytes. Mitotic index was performed in the second and the fourth groups. The percent of regeneration was also calculated. Immunohistochemistry technique was used for detection of CD34+ cells markers in liver tissues by using anti CD34+ cells antibodies [this technique is done in group 4 only]. Our results found that mean weights of rats and assumed liver weights, there were no statistical significant differences between the studied groups. PH group had shown higher regeneration rate than Benzene+ PH group; the former showed a mean loss of 19% [81 +/- 2.1% of regeneration] of their original weight by the end of the first week, and the latter a mean loss of 30% [70 +/- 0.7% of regeneration]. Number of binucleate cells there was a significant difference in benzene treated group compared to control group [p<0.05]. Mitotic index there was significant higher mitotic index in partially hepatectomized after bone marrow suppression by benzene than partially hepatectomized group [p<0.05]. We had used CD34 [CBRE8] antibody in our. It is indicated that the hepatocytes can regenerate the liver and restore its original size. Hematopoietic stem cells may habitat the endothelial cells in the liver. Their role in hepatic regeneration doesn't appear early after partial hepatectomy it mobilized from bone marrow to the damaged liver rlay in the liver tissues for long time [> 7 days] then differentiate into non parynchematous liver tissues

Effects of postnatal exposure to static magnetic field on the development of the cerebellar granule cells

Many studies were performed to evaluate the effects of static magnetic fields [SMFs] on the processes of proliferation and migration of cerebellar cells to their final postnatal destinations. Granule cells are the most abundant interneurons in the cerebellum. Progenitors of these neurons actively proliferate during the first 2 postnatal weeks in external granular layer [EGL]. The granule cells in the EGL migrate inwards to form the internal granular layer [IGL], and the EGL disappears. So the postnatal development of the cerebellum depends on their postnatal proliferation and migration which is vulnerable to any micro-environmental insult. to evaluated the light and electron microscopic changes occurred to the cerebellar granule cells of the pups after postnatal exposure to SMF [20 mT]. Postnatal exposure to SMFs showed that there was a significant thinning in the EGL at the beginning of the study at postnatal thy 4, this significant decrease in thickness progressed in the first week. At two weeks when normally the EGL starts to disappear, it showed persistent increase in its thickness indicating delayed migration. At all ages of exposed group [P], EGL contained many apoptotic cells and some degenerated cells. IGL showed significant decrease in its cellular density till the postnatal day 15 concomitant with the period of delayed migration in the EGL. At the postnatal days 22, the cells in IGL began to regain its near normal cellular density but the IGL showed disarrangement of its crowded granule cells with absence of appearance of regular glomeruli among them with appearance of some degenerated cells among the granule cells. Many cells of the IGL also showed areas of cytoplasmic vacuolation. Postnatal exposure to SMFs produces some delay in the development and appearance of more apoptotic cells. But some of these changes in different stages of the postnatal development of the cerebellar cortex began to be less apparent with advancement of age

Effects of prenatal exposure to static magnetic field on the development of the cerebellar purkinje cells

Many studies were performed to evaluate the effects of static magnetic fields [SMFs] on the processes of proliferation and migration of cerebellar cells to their final postnatal destinations. Purkinje cell [PC] as one of the most critical station for all afferent input to the cerebellum as well as the major output from the cerebellum either direct or indirect through the other cerebellar neurons and development of Purkinje cells depends on their postnatal migration which is vulnerable to any micro-environmental insult. To evaluate the light and electron microscopic changes occurred to the cerebellar PCs of the pups after prenatal exposure to SMF [20 mT]. Prenatal exposure showed a significant decrease in the number of PCs as compared with that number in the control group throughout the time of study with appearance of some pathological changes at the cellular level obvious from the postnatal day 4 till the end of the study, as there were many apoptotic cells, few cells degenerated with astrocytosis near the Purkinje cells with large cytoplasmic vacuoles inside the cells and many cells became atrophied cells. The prenatal exposure to static magnetic field led to decrease ability of the proliferation, delay in the development and appearance of some degenerative changes in different stages of the postnatal development of the cerebellar cortex and these changes persisted till the adult life

Effect of vitamin E on the biochemical and haematological changes produced by cadmium toxicity in kidneys of albino rats

Kidneys are the main excretory organ of the body, performing its function through elimination of nephrotoxicants as Cadmium [Cd]. We carried out this study to investigate the effects of vitamin E "alpha tocopherol", as an antioxidant compound, on Cd induced toxicity in the kidneys of albino rats. In experimental albino rats, intraperitoneal administration of Cd [0.4 and 0.6 mg/kg/day] for 12 weeks induced renal damage, which was evident from the increased levels of serum urea and creatinine with significant decrease in total proteins, body weight and hematological parameters. This was associated with a significant rise in Cd concentration both in kidneys and blood. Co-administration of alpha tocopherol as antioxidant resulted in improvement of the kidney functions. The present study suggests that the physiological, biochemical and cytoprotective potential effects of vitamin E in Cd toxicity might be due to its antioxidant properties, which could be useful for achieving optimum effects in treating Cd induced renal damage

Role of tumor necrosis factor-alpha on hepatic regeneration after partial hepatectomy in adult male albino rats

This study aimed to evaluate the effect of TNF- alpha on liver regeneration after seventy percent partial hepatectomy of male rats. Rats were divided into three groups: control, untreated partially hepatectomised group and Pentoxifylline [a drug which blocks TNF-alpha] treated hepatectomised group. Each group had thirteen rats. Rats were killed on the 1[st], 3[rd], 5[th] and 7[th] days posthepatectomy. The removed part of the liver was weighed to detect the increase of the total liver weight on the previous days. A sample of the liver was taken for histological and immunohistochemical studies. The weight of liver in the untreated group showed gradual increase up to more than ninety nine per cent of the original liver weight on the7[th] day posthepatectomy. In the treated group, it reached only fifty five per cent of the original liver weight on the 7[th] day posthepatectomy. Mitotic activity in the untreated group was sharply increased on the 1[st] day then gradually decreased and disappeared on the 7[th] day. Treated group showed a decreasing in mitotic activity from the1[st] day and disappearing on the 3[rd] day. Immunohistochemical studies in untreated group showed intense cytoplasmic overexpression for TNF- alpha on the 1[st] and the 3[rd] days, moderate overexpression on the 5[th] day and mild overexpression on the 7[th] day. Treated group showed mild overexpression on the 1[st] day and no expression on other day posthepatectomy. The study demonstrated that TNF- alpha promoted the regenerative changes that occur in the liver after partial hepatectomy

Craniofacial ossification in rat fetuses following prenatal exposure to dimethoate and carbosulfan insecticides

Pesticides, including insecticides, occupy a unique position among many chemicals that man encounters daily for the purpose of pest control in all agricultural programs. In fact, most of such chemicals are not highly selective and constitute potential hazard to many non-target species including man and other animals. The present study aimed to study the teratogenic effects of both dimethoate and carbosulfan insecticides on the ossification of craniofacial bones in albino rat fetuses. In this study, fifty female albino rats were allocated to ten groups [5/each group]; control, low dose dimethoate 1/40 LD50 [8.25 mg/kg], medium dose dimethoate 1/20 LD5O [16.5 mg/kg], high dose dimethoate 1/10 LD50 [33 mg/kg], low dose carbosulfan 1/40 LD50 [5.2 mg/kg], medium dose carbosulfan 1/20 LD50 [10.45 mg/kg], high dose carbosulfan 1/40 LD50 [20.9 mg/kg], mixed low doses of dimethoate and carbosulfan, mixed medium doses of dimethoate and carbosulfan, and mixed high doses of dimethoate and carbosulfan. Animals of all groups were sacrificed in the morning of 20[th] day of gestation. Then all specimens were stained with alizarin red stain for evaluation of ossification of skeletal system. The results of the present study revealed that both dimethoate and carbosulfan insecticides, had a deleterious effect on the ossification of craniofacial bones and that the most affected bones were supraoccipital, presphenoid, and interparietal bones. These effects were marked in the high doses and mixed low dose groups. It is concluded that the deleterious effects were increased with the increasing dose of either dimethoate or carbosulfan insecticides and that the mixture of low doses had an effect near to that of medium and sometimes high doses

Teratogenic effects of dimethoate and carbosulfan insecticides on albino rat fetuses

The present study deals with the teratogenic effects which occur in albino rat fetuses after intragastric administration of different doses of dimethoate and carbosulfan insecticides, either separately or in combination, to pregnant albino rats. In this study, fifty female albino rats were allocated to ten groups [5/each group]; control, low dose dimethoate 1/40 LD50 [8.25 mg/kg], medium dose dimethoate 1/20 LD50 [16.5 mg/kg], high dose dimethoate 1/10 LD50 [33 mg/kg], low dose carbosulfan 1/40 LD50 [5.2 mg/kg], medium dose carbosulfan 1/20 LD50 [10.45 mg/kg], high dose carbosulfan 1/40 LD50 [20.9 mg/kg], mixed low doses of dimethoate and carbosulfan, mixed medium doses of dimethoate and carbosulfan, and mixed high doses of dimethoate and carbosulfan. All pregnant females in mixed medium doses of dimethoate and carbosulfan group died between 9th and 11[th] day of gestation, while those in mixed high doses of dimethoate and carbosulfan died between 8th and 10[th] day of gestation. Animals of all groups were sacrificed in the morning of 20th day of gestation. The external manifestation of poisoning with dimethoate and carbosulfan, embryolethality, live and dead fetuses, placental weight, external abnormalities of fetuses, fetal weight, crown-rump length, biparietal diameter had been monitored. The results of the present study denoting that both dimethoate and carbosulfan insecticides, had a deleterious effects on embryolethality in the form of increased percentage of preimplantation loss, an increased percentage of resorptions, and decreased percentage of live fetuse. Also, both dimethoate and carbosulfan insecticides had a deleterious effects on fetal growth in the form of reduction of, fetal weight, crown-rump length, and biparietal diameter. It is concluded that dimethoate and carbosulfan insecticides had a deleterious effects on fetal growth and embryolethality, this effect is dose-related, and that the mixture of low doses had an effect near that of medium and sometimes high dose of dimethoate and carbosulfan insecticides

Influence of prenatal protein under nutrition on apical dendritic length and cytoplasmic RNA in pyramidal neurons of prefrontal cortical layers in albino rat pups

Protein malnutrition is a major problem in developing countries affecting mainly newborns and children during the most critical stage of their brain development. Protein deficiency can alter brain development causing structural and functional deficits. The purpose of the present study is to determine the effect of prenatal protein under nutrition on apical dendritic length and cytoplasmic RNA of pyramidal neurons in prefrontal cortical layers in albino rat pups. Pregnant rats were divided into two groups [Control and undernourished], ten dams each. All dams were fed 20% protein diet till 14th gestational day, and then undernourished group was fed 6% protein diet. At birth pups were scarified by over dose of ether. The selected samples was fixed in Bouin's fixative, then processed and embedded in paraffin wax. Sections of 6 microm thicknesses were prepared for the methyl green-pyronin stain for DNA and RNA. Sections [median sagittal] 10 microm thickness in prefrontal cortex were prepared and stained with Silver stain. Silver stained sections were used for measurements of apical dendritic length of neuron in all layers of prefrontal cortex at x 400 magnification. Methyl green-pyronin stain for was used for measurements of optical density for RNA at x 400 magnification by using image pro-plus program. The apical dendritic length in undernourished was significantly less in all layers compared to control. Cytoplasmic RNA was significantly less in the cells in experimental group in all cortical layers compared to control; except layer V, was more in undernourished group than control. Prenatal protein under nutrition decreased apical dendritic length in all prefrontal cortical layers and reflected on the amount of cytoplasmic ribosomal RNA which is also decreased

Influence of prenatal protein under nutrition on neuron packing density of prefrontal cortex in albino rat pups

Nutrition is probably the single greatest environmental influence both on the fetus and neonate, and plays a necessary role in the maturation and functional development of the central nervous system. The purpose of the present study is to determine the effect of prenatal protein under nutrition on neuron packing density of prefrontal cortex in albino rat pups. Pregnant rats were divided into two groups [Control and undernourished], ten dams each. All dams were fed 20% protein diet till 14th gestational day, and then undernourished group was fed 6% protein diet. Taking undernourished diet from 14th gestational day. At birth pups were scarified by over dose of ether. The growth parameters [body weight, head length and biparietal diameter] were taken. Brain parameters [weight, width and anteroposterior diameter of cerebral cortex] were recorded. The selected samples from prefrontal cortex were prepared for toluidine blue stain. Number of neurons in each layer of prefrontal cortex was counted at x 400 magnification by using Image pro plus program. The results revealed that prenatal protein under nutrition decreased significantly growth parameters [body and brain weight, biparietal diameter and width of cerebral hemisphere]. Prenatal protein under nutrition decreased significantly neuron packing density in superficial layers of prefrontal cortex [I and II] more than layers [III-IV]. Prenatal protein under nutrition found to decrease significantly growth parameters in newly born pups. Also, it decreased significantly neuron packing density in superficial layers of prefrontal cortex due to delay of neuronal migration to these layers

Influence of low frequency electric and magnetic fields exposure on albino rat placentation following maternal exposure during early and late periods of embryogenesis

Background: with the phenomenal growth in the use of extremely low frequency electromagnetic fields EMFs, there has been a surge of interest concerning the possible harmful biological effects of electromagnetic fields EMFs with a frequency of 50-60 Hz on the human body

Aim of the work: The aim of the present study is to evaluate the histological changes in the placenta after exposure to low frequency electric and magnetic fields during two different critical periods of embryogenesis

Methods: twenty-four pregnant albino rats were randomly divided into three equal groups: control, early exposed and late exposed. Both exposed groups were exposed to 50 Hz magnetic field of intensity 1.5G and a strong electric field of intensity 10KV/m. The EMFs exposure started from gestational day 6 through day 10 in the early exposed group and from gestational day 11 through day 15 in the late exposed group. Twenty day full term placenta were then collected and examined histological through light microscopy using hematoxylin and Eosin stains

Results: The present study indicated that 50Hz EMFs exposure the low frequency EMFs exposure in the early and late period affect the placentation of albino rats. Also EMFs exposure in the early period cause changes in rat placenta more than that occurred in the late exposure except the deciduas was more affected in late exposure

Conclusions: So it is suggested that exposure to appliances that producing EMFs must be limited especially during pregnancy

Craniofacial bones development in albino rat fetuses following maternal exposure to low frequency electric and magnetic fields during early and late periods of embryogenesis

Background: With the progressive development of the electrical industry, several workers have studied the effects of electromagnetic fields on cells, organs and tissues through animal studies to investigate the possible harmful biological effects on the human body

Aim of the work The aim of the present study is to evaluate the frequency and pattern of craniofacial bones ossification of 18 and 20-day albino rat fetuses, following maternal exposure to low frequency electric and magnetic fields in the early and late periods of embryogenesis

Methods: Forty eight pregnant albino rats were randomly divided into two age groups [18 and 20 day] each of them was subdivided into three equal groups: control, early exposed and late exposed. Both exposed groups were exposed to 50Hz magnetic fields of intensity 1.5G and a strong electric field of intensity 10KV/m. The EMFs exposure started from gestational day 6 through day 10 in the early exposed group and from gestational day 11 through day 15 in the late exposed group. 18 and 20-day fetuses were then collected and their skeletons were stained with Alizarin red for their evaluation

Results: The present study indicated that 50 Hz EMFs exposure decreased the craniofacial bones development either in the early or late exposed groups but more marked and more delayed in the early exposed group in 18-day fetuses. The early period of embryogenesis was the most critical period for ossification of craniofacial bones

Conclusion: So it is suggested that exposure to appliances that producing EMFs must be limited especially during early period of pregnancy