Physicochemical, surface and catalytic properties of Co3O4/Mn2O3 and Mn2O3/Co3O4 systems

The two catalytic systems were prepared using equimolar proportions of cobalt nitrate and manganese carbonate [Co3O4/Mn2O3] and manganese carbonate and cobalt nitrate Mn2O3/Co3O4]. The mixed solids were subjected to heating at 500, 700, and 900°C. The solid - solid interactions taking place in the two catalytic systems were followed up using XRD investigation. Their specific surface areas were determined from nitrogen - adsorption isotherms carried out at - 196°C. Their catalytic activities were studied via following up the kinetics of CO oxidation by O2 at 125-400°C using a static method. The results obtained revealed that solid - solid interaction took place between cobalt and manganese oxides at 500 - 900°C yielding cobalt manganite and manganese cobaltite. In Co3O4/Mn2O3 system, a complete conversion of cobalt and manganese oxides took place at 900°C to yield cobalt manganite. In the other system, however, a partial conversion of Mn2O3/Co3O4 took place at 900°C. The specific surface areas of the two investigated systems are close to each other and decrease by increasing their calcinations temperature within 500 - 900°C.The decrease was, however, more pronounced by increasing the calcinations temperature from 700 to 900°C. The catalytic activity of Mn2O3/Co3O4 is smaller than that measured for the other system calcined at 500 °C. Opposite results were observed for the solids calcined at 700°C and 900°C. The catalytic reaction proceeds via almost the same mechanism in contact with different solids

Studies on some physicochemical, surface and catalytic properties of CuO - ZnO/Al2O3 system prepared by coprecipitation

Four copper - zinc aluminium mixed oxides having different composition were prepared by coprecipitation method. The prepared solids were calcined at 400 - 800 degree C. Some physicochemical, surface and catalytic properties of the systems investigated were studied using XRD, EDX, nitrogen adsorption at 196 degree C and catalytic oxidation of CO by O2 at 100 - 200 degree C.The results revealed that all investigated solids consisted of nanocrystalline CuO and ZnO phases even those calcined at 800 degree C.The surface characteristics of different adsorbents were strongly dependent on their chemical composition and calcination temperature. The SBET decreased by increasing both the copper oxide content and calcination temperature. The value of 132m 2/g was computed for the system containing the smallest amount of CuO and being calcined at 400 degree C. The activation energies of sintering for different solids were determined from the values of SBET as being influenced by calcination temperature. The catalytic activities, in CO - oxidation by O 2, for all solids were found to increase by increasing both CuO content and calcination temperature. The activation energies of the reaction have been determined

Sodium fluoride-induced testicular toxicity in rats: the possible modulatory effect of quercetin

To Investigate the possible modulatory effects of quercetin [QE] against sodium fluoride [NaF]-mnduced testicular toxicity in rats and to highlight the underlying mechanisms of such protection. Forty adult male rats were classified into four groups; group [I] was served as control. Group [2] was administered NaF [20 mg/kg/day for 30 consecutive days]. Group [3] was received QE [IS mg/kg/day for 30 consecutive days. Group [4] was received QE 24 h prior to NaF administration for 30 consecutive days. Significant decreases in the normal relative testes weight, testicular lactic dehydrogenase [LDH-x] isoenzyme activity, sperms count and motility as well as daily sperm production were observed. The association of NaF-induced testicular toxicity with oxidative stress cascade was also investigated. Significant elevation in testicular level of salondialdehyde [M DA] accompanied with marked reductions in reduced glutathione [GSH] content and superoxide dismutase [SOD] activity were shown. Treatment with QE prior to NaF revealed marked mitigations in the studied functional parameters of the testes. In addition, the lowered activity of SOD and GSI-I content in the testicular tissue were elevated. The high level of MDA lended to be normalized. The data showed the capability of QE to ameliorate NaF-induced testicular toxicity through its antioxidant potential

Evaluation of the potential protective effect of captopril against doxorubicininduced cardiotoxicity in rats

The purpose of this study was to investigate the possible protective effect of Cap, an angiotensin-converting enzyme inhibitor with an antioxidant property, against DOXinduced cardiotoxicity. Results of the present study showed that DOX decreased significantly plasma activities of CK, CK-MB and LDH, while it produced a significant increase in serum NO level, cardiac MDA level and CAT activity. Significant reductions in cardiac GSH level and GPx activity were also produced. Administration of Cap one hour before DOX treatment attenuated the reduction in CK-MB activity. The combined treated group showed significant decrease in cardiac MDA level. Also, DOX concentration was markedly decreased in both serum and cardiac tissue. Data of the present study showed that Cap had limited protective effect on cardiotoxicity produced by DOX treatment. The mechanism by which Cap exerts its protective effect may involve inhibition of lipid peroxidation

Predictors of treatment failure among tuberculosis patients under DOTS strategy in Egypt

Treatment failure is a serious problem facing some national tuberculosis [TB] control programmes. Irregularity of treatment is a factor that can lead to treatment failure. A case-control study was carried out in TB centres in Egypt during April 2001-December 2002 aimed at investigating the predictors of treatment failure. We interviewed 119 people with treatment failure and an equal number of cured cases [controls] and their families regarding sociodemographic characteristics, information about TB, information about drugs, treatment compliance, family support and patient-family interaction. Significant risk factors for treatment failure were non-compliance to treatment, deficient health education to the patient, poor patient knowledge regarding the disease and diabetes mellitus as co-morbid condition

Effects of ICRF-187 and L-carnitine on bleomycin-induced lung toxicity in rats

The possible modulatory effects of ICRF-187 and L-carnitine against bleomycin -induced pulmonary toxicity in male rats were investigated. Repeated administration of bleomycin [10mg/kg, twice weekly for 6 consecutive weeks] produced significant lung toxicity. The toxicity was manifested by significant increase in normal contents of lipid peroxide [LPO. 91.7%], reduced glutathione [GSH, 73.2%] and oxidised glutathione [GSSG, 135,4%] as well as the activity of superoxide dismutase [SOD, 222.7%]. Thirty minutes prior to bleomycin treatment, other groups of rats were received either ICRF-187 [95 mg/kg] or L-carnitine [500 mg/kg] adopting the same schedule of treatment as in bleomycin-treated group. L-carnitine decreased bleomycin-induced elevations in SOD activity, GSH and GSSG contents, however, it failed to suppress the increase in LPO level. On the other hand,. treatment with ICRF-187 returned back all the elevated biochemical parameters induced by bleomycin to nearly normal levels. In conclusion, the results of this study showed a potential capability of ICRF-187 to mitigate the bleomycin-induced lung injury. Moreover, despite the inability of L-carnitine to change the elevated LPO content, it was able however, to decrease the elevated endogenous antioxidant parameters

influence of testosterone administration on the partially extirpated submandibular salivary gland in rat

This study was carried out in order to investigate the effect of testosterone administration on the regenerative power of the extirpated submandibular gland of rats. Thirty two Spargue-Dawley rats weighting about 240 gm were divided into two groups, 16 animals for each. In group 1 about half of right submandibular gland was removed and the animals were injected intraperitoneally at five successive days by testosterone. At different intervals [1,7,15 and 30 days] four rats were sacrified. Morphological and histochemical studies revealed healing of the extirpated area occured as a result of regeneration of secretory part by formation of newly formed serous acini from the old ones at the line of section and from rudimentary ducts in the central area. In the central area, the periductal cells were transformed into acinar cells and later, some of the straited ducts changed further to form granular convoluted tubules. In our study, group II revealed progressive newly formed acini and ducts. Some of these ducts demonstrated apical vacuolization within the first period, which could be considered as earlier sign of transformation into granular convoluted tubules, which appeared in later period in control groups. The lumina of these ducts appeared with eosinophilic products, which might indicate either that lumina carry acinar secretions or producing such material. The acini of group II became larger and its cytoplasm appeared as honeycombed appearance due to fusion of the secretory granules together. The appearance of the mucous cells or acini in group II may arise either from the proliferation of the already found mucous cells or as a result of sexual maturity. The newly formed acini showed strong PAS reaction, which decreased with maturation, denoting increase in the metabolic activity. The study has demonstrated that after testosterone administration the regenerative process of the submandibular gland was accelerated

potential value of serum osteocalcin in patients with metastatic breast cancer

Serum osteocalcin, a modern and sensitive marker of bone turnover, was measured in 60 female breast cancer patients and 8 healthy subjects as control. Patients were subdivided into 3 groups: The first group [group A] included postmastectomy patients in complete clinical remission, the second group [group B] involved those with visceral metastases or extraosseous metastases, while the third group [group C] represented those with bone metastases +/- extraosseous metastases. It was concluded that serum osteocalcin level increased in breast cancer patients with bone metastase, but decreased in those with visceral metastases. Also, it may be more important in evaluating bone metastases in breast cancer patients than serum alkaline phosphatase

impact of health education on the knowledge and attitude of Egyptian nurses towards occupational HIV infection

There is a phobia about nursing human immunodeficiency virus [HIV] infected patients. This work was carried out to study the impact of health education on the knowledge and attitude of nurses, representing a stratum of health care team, about modes of transmission and prevention of occupational HIV infection. The studied population were students of the High Institute of Nursing, they were subjected to a health education program [HE], and assessment was carried out before and after this intervention. The results revealed that health education is a successful tool in improving the knowledge of the nurses and in minimizing their phobia from occupational HIV infection

Study of the knowledge, attitude of Egyptian health care workers towards occupational HIV infection

Acquired imnuino-deficiency syndrome [AIDS] was reported for the first time in Egypt in 1986. Up to March 1993, 60 cases were notified to the Ministry of Health and 359 were detected to be infected with human immunodeficiency virus [HIV]. Most cases had acquired infection abroad through blood, blood products or sexual contact. The number of cases is continuously increasing. Fear and ignorance about HIV infection causes panic among health care workers [HCWs] whenever a case is discovered and needs medical care. We assessed the knowledge and attitude of 346 HCWs towards the probability of occupational HIV infection using a self administered questionnaire. The sample included physicians, surgeons, nurses, laboratory technicians and ambulance workers. 72.8% of HCWs believed that they are in "great" danger of acquiring AIDS through occupational exposure whereas 0.6% thought that there was no danger. 67% of HCWs had wrong ideas about transmission of HIV [toilet seats, droplet infection, touching patients]. 83.5% mentioned that AIDS patients should be isolated in quarantine. The main source of information about AIDS was the television, radio and ordinary press. 44.8% got their information from textbooks or scientific literature. 95.4% felt the need for more information about infection and disease. The results show an urgent need to start a program of education of BCWs concerning the risk of occupational HIV infection and the measures of its prevention

Potentiation of the chemotherapeutic effect of methotrexate by hyperthermia in experimental animal tumor model

Evidence was obtained for the augmentation of cytotoxic effect of methotrexate [MTX] when combined with hyperthermia [HPT] in vivo. Results showed that Ehrlich tumor bearing mice injected i.p. with a single dose of MTX [1 mg/kg] 1 hour prior to local treatment with HPT [43C for 30 minutes] produced 2-fold enhancement of the tumor growth delay induced by MTX alone. Treatment of HPT alone for 3 times every other day produced 41.5% tumor regression, however, combined treatment of MTX and HPT produced 76.3% decrease in tumor volume compared to their volume before the treatment. The molecular mechanisms responsible for this potentiation were investigated by assaying tumor tissue contents of DNA, RNA and protein, and their rate of synthesis. Total lipid, cholesterol as well as activities of acid phosphatase and acid ribonuclease were also determined

transplacental carcinogenic promoting activity of chloroacetonitrile the role of L-ornithine and its relation to glutathione content in embryonic tissue

The possible transplacental carcinogenic promoting activity of chloroacetonitrile [CAN, a by-product of drinking water chlorination process] in timed pregnant mice was studied. The activity was investigated through the assessment of the embryonic ornithine-decarboxylase [ODS] activity in relation to the embryonic glutathione [GSH] content after maternal administration of CAN. CAN was administered orally in a single dose of 25, 50, 70, 100 and 150 mg/kg diluted in 0.2 ml corn oil to the pregnant mice [GD 11.5]. All mice were killed 2 hours after treatment and the embryonic tissue was prepared for analysis. Also, a time course study protocol was studied, CAN was given in a single oral dose of 25 or 75 mg/kg to the pregnant mice and they were killed at 2, 6, 12, 24 and 48 hours post-treatment at GD 11.5. Maternal administration of CAN in doses of 25, 50, 75 mg/kg produced a marked increase in ODC activity expressed as pmole 14CO2/mg protein/30 min., associated with a significant reduction in GSH content. However, treatment with CAN either in a dose of 100 or 150 mg/kg showed significant reductions in ODC activity and GSH content. Concerning time-course study protocol, maternal administration of CAN either in 25 or 75 mg/kg produced a significant increase in the embryonic ODC activity accompanied with a remarkable decrease in GSH content measured at 2, 6, 12, 24 and 48 hours post-maternal treatment. The increase in the embryonic carcinogenic marker ODC which was associated with GSH depletion after administration of non-cytotoxic doses of CAN reflected an indication towards the mechanistic pathway of the transplacental carcinogenic promoting potential of CAN