Gamalat Y. Osman

Histamine Immunoreactive Elements in the Central and Peripheral Nervous Systems of the Snail, Biomphalaria spp., Intermediate Host for Schistosoma mansoni

Histamine appears to be an important transmitter throughout the Animal Kingdom. Gastropods, in particular, have been used in numerous studies establishing potential roles for this biogenic amine in the nervous system and showing its involvement in the generation of diverse behaviours. And yet, the distribution of histamine has only previously been described in a small number of molluscan species. The present study examined the localization of histamine-like immunoreactivity in the central and peripheral nervous systems of pulmonate snails of the genus Biomphalaria. This investigation demonstrates immunoreactive cells throughout the buccal, cerebral, pedal, left parietal and visceral ganglia, indicative of diverse regulatory functions in Biomphalaria. Immunoreactivity was also present in statocyst hair cells, supporting a role for histamine in graviception. In the periphery, dense innervation by immunoreactive fibers was observed in the anterior foot, perioral zone, and other regions of the body wall. This study thus shows that histamine is an abundant transmitter in these snails and its distribution suggest involvement in numerous neural circuits. In addition to providing novel subjects for comparative studies of histaminegic neurons in gastropods, Biomphalaria is also the major intermediate host for the digenetic trematode parasite, which causes human schistosomiasis. The study therefore provides a foundation for understanding potential roles for histamine in interactions between the snail hosts and their trematode parasites.

The hepatoprotective activity of blue green algae in Schistosoma mansoni infected mice.

This study aims to evaluate the immunomodulatory effects of a natural product, blue green algae (BGA) (100 mg/kg BW), alone or combined with praziquantel PZQ (250 mg/kg BW) on granulomatous inflammation, liver histopathology, some biochemical and immunological parameters in mice infected with Schistosoma mansoni. Results showed that the diameter and number of egg granuloma were significantly reduced after treatment of S. mansoni-infected mice with BGA, PZQ and their combination. The histopathological alterations observed in the liver of S. mansoni-infected mice were remarkably inhibited after BGA treatments. BGA decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) as well as the level of total protein (TP) while the level of albumin was increased. Treatment of infected mice with BGA, PZQ as well as their combination led to significant elevation in the activities of hepatic antioxidant enzymes glutathione peroxidase (GPX) and glutathione-S-transferase (GST) as compared with control group. Combination of BGA and PZQ resulted in significant reduction in the level of intercellular adhesion molecules-1 (ICAM-1), vascular adhesion molecules-1 (VCAM-1) and tumor necrosis factor-alpha (TNF-α) when compared to those of the S. mansoni-infected group. Overall, BGA significantly inhibited the liver damage accompanied with schistosomiasis, exhibited a potent antioxidant and immunoprotective activities. This study suggests that BGA can be considered as promising for development a complementary and/or alternative medicine against schistosomiasis.

Biohazards of the biofungicide, Trichoderma harzianum on the crayfish, Procambarus clarkii: Histological and biochemical implications

Abstract Pesticides are one of the pollutants threatening aquatic invertebrates living in the tributaries of the River Nile. So, the effect of the biofungicide, Trichoderma harzianum on the crayfish, Procambarus clarkii and its influence on electrophretic pattern of proteins and tissue pathology of gonads were studied. Different concentrations of T. harzianum (100, 50, 40, and 20%) were used. The potency of T. harzianum to genocide ranged from many hours (less than a day) with 100% concentration to 39 day of treated with 20% concentration. Electrophoretic analysis was done to compare protein patterns of muscles from control and treated animals with 20% T. harzianum. The result recorded decrease in protein density of males and females post exposure to T. harzianum after one week (this decrease was more in males than females). However, the protein density increased four weeks post exposure to T. harzianum (this increase was more in females than in males). T. harzianum caused some histobathological changes in testis after four weeks post exposure when compared to the control. The testis showed deformed architecture, some testicular acini showed incomplete fusion and others with elongated shape. On the other hand, the ovary exhibited severe damage in oogenetic pouch like detachment of ovarian epithelium, fusion between some oogenetic pouches, and necrosis in connective tissue. It can be concluded that, T. harzianum has deleterious effects on the proteins and gonads of P. clarkii that may lead to disturbance/decrease in productivity and even death to this organism and the surrounding environment.

Influence of Solar Energy on Encysted Parasitic Protozoa Giardia and Entamoeba spp in Water-Treatment Plants, Egypt

Polluted water with parasitic protozoa (Giardia lamblia and Entamoeba histolytica) causes many serious health problems like diarrhea and gastrointestinal diseases. The present study investigated the applicability of solar energy for disinfection of parasitic protozoa in polluted water. One-side blackened bottles of two liters volume each were continuously exposed to direct sun light for about seven hours which maintained water temperature in the range of 50-60 °C that was enough for destroying most of the encysted parasitic protozoa. Complete destruction of the encysted protozoa was achieved in both bottles facing south and those vertically in position at 60 °C with an ambient temperature of 40 °C. The influence of water temperature against the viability of these two cysts was found to be highly significant (P < 0.001) in both cases particularly those of Giardia where its regression coefficient equal -1.5 as compared to that of Entamoeba (-1.27). The low cost and operational simplicity of this study make it affordable and usable. It is more useful in rural areas where other sources of energy like electricity and gas are not easily available.

Preliminary study on induction of sex reversal inMeloidogyne javanica (Chitwood) andTylenchulus semipenetrans (Cobb) nematodes by testosterone

Sex hormone, testosterone, was used to induce the function of sex reversal in the two nematode genera, by treatingM. javanica andT. semipenetrans egg-masses and new hatched larvae. The percentages of males were 80 and 62.5%, respectively, when applying testosterone three times, the first on egg-masses, the second and the third on hatched larvae at 10 ppm concentration. Percentage of males was increased by 45.83 forM. javanica in comparison with the check. Also, the sex hormone decreased the percentage of citrus nematode females that infected the root with 80%. Consequently, this means that the males percentage was increased.In addition, the reduction percentages of the total nematode population forM. javanica andT. semipenetrans treated with testosterone were 33.33 and 80%, respectively.These results indicate that the use of testosterone to induce the function of sex reversal is promising as a new approach for controlling parasitic nematodes,M. javanica andT. semipenetrans on tomato and sur orange, respectively. Testosterone showed two dimensions in this respect, the first is in changing the population sex ratio, where the percentages of males were increasing and decreasing the total population in comparison with the check in both nematode genera.ZusammenfassungDas Sexualhormon Testosteron wurde angewandt, um die Ausbildung des Geschlechts vonM. javanica undT. semipenetrans durch Behandlung der Eigelege und der frischgeschlüpften Larven zu beeinflussen. Bei dreimaliger Anwendung des Hormons bei den Eigelegen, sowie den Zweit- und Drittlarven, betrug der Männchen-Anteil der beiden Nematodenarten 80 bzw. 62,5%. Dabei wurde der Männchenanteil vonM. javanica um 45,8% gegenüber Kontrolle erhöht. BeiT. semipenetrans wurde bei gleicher Anwendung der Weibchenanteil um 80% vermindert, was ebenfalls einen Anstieg der Männchenquote bedeutete.Weiterhin wurde durch die Testosteron-Anwendung die Gesamtpopulation vonM. javanica um 33,3% und diejenige vonT. semipenetrans um 80% vermindert.Diese Ergebnisse zeigen, daß der Gebrauch von Testosteron zur Beeinflussung des Geschlechterverhältnisses einen neuen aussichtsreichen Weg zur Bekämpfung der pflanzenparasitären NematodenM. javanica undT. semipenetrans darstellt. Die Wirkung des Hormons ist dabei eine zweifache: Verringerung des Weibchenanteils sowie Verminderung der Gesamtpopulation der Nematodenart.