ABSTRACT
Extracts from 2 algal species [Hypnea esperi and Caulerpa prolifera] from Suez Canal region, Egypt were screened for the production of antibacterial compounds against some pathogenic bacteria. The bacteria tested included Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Aeromonas hydrophila, Bacillus subtilis and Staphylococcus aureus. Algal species displayed antibacterial activity. The methanolic extracts showed variable response by producing various zones of inhibition against studied bacteria. The tested Gram-negative bacteria were less affected by studied algal extracts than Gram-positive bacteria. We determined some biopotentials properties such as cytotoxicity and anticoagulant activity of most potent algal active extracts. The secondary metabolites of only Hypnea esperi algal extract effectively prevented the blood clotting to the extent of 120 seconds. Minimum inhibitory concentration [MIC] indicated that all potent tested algal extract C inhibits Bacillus subtilis and Staphylococcus aureus. Minimum bactericidal concentration [MBC] was between 1 and 1.4mg/ml. The algal isolates from Egypt have been found showing promising results against infectious bacteria instead of some synthetic antibiotics
Subject(s)
Chlorophyta , Anti-Bacterial Agents , Anticoagulants , Microbial Sensitivity Tests , Plant Extracts , CytotoxinsABSTRACT
Whether satellite cell nuclei are more common in the vicinity of motor endplates than in extrasynaptic regions of rat muscle is not clear. If this were true, then perisynaptic satellite cells could play a role in the preservation of the endplate. We compared the frequency of satellite cell nuclei in the perisynaptic and extrasynaptic regions of rat soleus muscle. An absolute as well as a relative increase of perisynaptic satellite cells was found. The mean frequency of satellite cell nuclei per sarcomere was 0.016 in perisynaptic regions and 0.002 in extrasynaptic regions [P=0.01]. Also, perisynaptic satellite cells had many processes, and some features suggested a more active state. It was suggested that satellite cells might add to the pool of junctional myonuclei which synthesize acetylcholine receptor molecules, or help in the repair of the postsynaptic membrane. Alternatively, they may synthesize basal lamina components which are specific for the endplate
ABSTRACT
The effect of methyl mercury [MeHg] on the neuropil of the molecular cell layer of the cerebellzrr cortex of the mouse embryo was studied by the electron microscope. Fifteen adult mice [12 females and 3 males] were used in this study. From the lSt day of gestation, the pregnant female mice were provided with drinking water containing 4% MeHg. The developing cerebellum of the foetal mice was examined on the 14th day of gestation. The neuropil showed swollen dendritic profiles with clear dendroplasm, axonal knobs with degenerated synaptic vesicles and axo-dendritic contact without synaptic thickening. After 17 days of gestation, the dendritic profiles appeared swollen with immature mitochondria and few free ribosomes, axonal knobs with defined synaptic vesicles and axo-dendritic contacts with synaptic thickening. After 20 days of gestation, the dendritic profiles were swollen with immature ribosomes. The axonal knobs were observed containing illdefined synaptic vesicles. The axo-dendritic and axo-somatic contacts were recognized. They were of symmetrical synaptic thickening. From the above-mentioned observations, it appeared that exposure to methyl mercury caused permanent marked damage to the cerebellum. So, exposure to methyl mercury should be avoided
ABSTRACT
The present study investigated the role of the neural cell adhesion molecule [N-CAM] in maintaining the integrity of the neuromuscular junction. Immunohistochemical localization of this molecule in muscle tissue of the rat was examined through double immunostaining of longitudinal cryostat sections for synaptophysin [a synaptic vesicle marker] and N-CAM. In addition, immunoelectron microscopy was performed to view the localization of N-CAM at the ultrastructural level. The results showed that N-CAM immunoreactivity at the neuromuscular junction was exclusively restricted to the contact area between the terminal Schwann cells and the nerve terminals. No reaction product could be seen between the pre-and postsynaptic membranes. Such localization of NCAM implies that this molecule is not adequately positioned to play a role in maintaining the integrity of the neuromuscular junction, but rather mediates the axon-Schwann cell interactions
ABSTRACT
One of the major health problems is the wide incidence of cancerous diseases as a result of air, water and food pollution. Endoxan is a widely used anti-cancer immunosuppressive drug that affects' fertility in men. The aim of the present work was to study the side effects of endoxan on the testis. Ten adult white male rats were divided into two groups, the first group [consisted of 4 rats] was given normal saline and used as controls. The second group [consisted of 6 rats] was treated with 100mg/kg/day endoxan intraperitoneally for one week. The rats were sacrificed and prepared for electron microscopic examination. The treated testis showed irregular basement membrane either in thickness or in its outline. The cytoplasm of Sertoli cells showed lysosomes and vacuoles. The spermatogenic cells revealed vacuoles in its cytoplasm. Its mitochondria became swollen and lost their cristae and were arranged peripherally near the cytoplasmic membrane. Degeneration of chromatin was detected. The spermatid revealed abnormalities in the fonn of irregular acrosomal vesicles, appearance of vacuoles in its head, in addition to the presence of abnormal heads
ABSTRACT
In order to better understand the role played by the ciliary neurotrophic factor [CNTF] during nerve growth, we have investigated the localization of this factor in normal skeletal muscle and neuromuscular junctions of the rat. In addition, we have investigated the changes in CNTF immunoreactivity in botulinum-toxin-paralyzed rat muscle. This animal model was characterized by local muscle inactivity which was accompanied by profuse terminal nerve growth. The results showed that CNTF immunoreactivity in normal rat muscle was localized in Schwann cells surrounding myelinated intramuscularand preterminal nerve fibres. No staining was seen in Sehwann cells overlying the unmyelinated nerve terminals nor within axons or nerve terminals. Secondly, we have demonstrated that CNTF immunoreactivity did not show any changes in botulinum-toxin-paralyzed muscle from the control muscle [neither during terminal nerve growth nor during the formation of new neuromuscular junctions]. In view of the present findings, and previous reports, it is suggested that CNTF has no role during growth of nerve fibres, but rather during the process of myelination, or perhaps, thickening and maturation of nerve fibres