Effect of high-fat diet-induced obesity on thyroid gland structure in female rats and the possible ameliorating effect of metformin therapy.

BACKGROUND: Obesity is known to induce a state of lipotoxicity that affects the different organs of the body. Metformin is an antidiabetic drug commonly used in obesity treatment. It was known to improve thyroid function and its regulating hormones. Structural changes in the thyroid gland associated with obesity have not been well investigated. So, the aim of the present study is to detect structural changes in thyroid gland induced by obesity and to investigate the possible protective role of metformin therapy. MATERIALS AND METHODS: Thirty adult female albino rats were divided into three groups (10 rats each). Group I (control group), group II (rats fed with a high-fat diet), and group III (rats fed with a high-fat diet and treated with metformin therapy). After 12 weeks, rats from all groups were sacrificed. Blood samples were taken for measurement of lipid profile, thyroid stimulating hormone (TSH), free T3 and free T4. Thyroid glands were extracted and processed for histological and ultrastructural study. Morphometric measurements for the colloid area of thyroid follicles and height of the follicular cells were done. RESULTS: Group I displayed normal biochemical parameters and architecture of the thyroid gland. Group II revealed disordered lipid profile, high TSH, free T3 and T4. Microscopically, large thyroid follicles with excessive colloid accumulation and decreased follicular cells height were seen. Some follicular cells showed pyknotic nuclei, vacuolated cytoplasm and disrupted basement membrane with mast cell infiltration of the thyroid tissue. Ultrastructurally, group II follicular cells showed loss of apical microvilli, dense shrunken nuclei, dilated endoplasmic reticulum, swollen damaged mitochondria with large intracellular vacuoles and colloid droplets. In group III, the biochemical parameters and structure of thyroid follicles were improved, and they had a near-normal appearance. CONCLUSIONS: Obesity induced by high-fat diet in female rats structurally and functionally changed the thyroid gland in a way that may explain hypothyroidism associated with obesity. These changes were improved by metformin therapy.

D-Amino acid oxidase-induced oxidative stress, 3-bromopyruvate and citrate inhibit angiogenesis, exhibiting potent anticancer effects.

Angiogenesis is critical for cancer growth and metastasis. Steps of angiogenesis are energy consuming, while vascular endothelial cells are highly glycolytic. Glioblastoma multiforme (GBM) is a highly vascular tumor and this enhances its aggressiveness. D-amino acid oxidase (DAO) is a promising therapeutic protein that induces oxidative stress upon acting on its substrates. Oxidative stress-energy depletion (OSED) therapy was recently reported (El Sayed et al., Cancer Gene Ther, 19, 1-18, 2012). OSED combines DAO-induced oxidative stress with energy depletion caused by glycolytic inhibitors such as 3-bromopyruvate (3BP), a hexokinase II inhibitor that depleted ATP in cancer cells and induced production of hydrogen peroxide. 3BP disturbs the Warburg effect and antagonizes effects of lactate and pyruvate (El Sayed et al., J Bioenerg Biomembr, 44, 61-79, 2012). Citrate is a natural organic acid capable of inhibiting glycolysis by targeting phosphofructokinase. Here, we report that DAO, 3BP and citrate significantly inhibited angiogenesis, decreased the number of vascular branching points and shortened the length of vascular tubules. OSED delayed the growth of C6/DAO glioma cells. 3BP combined with citrate delayed the growth of C6 glioma cells and decreased significantly the number and size of C6 glioma colonies in soft agar. Human GBM cells (U373MG) were resistant to chemotherapy e.g. cisplatin and cytosine arabinoside, while 3BP was effective in decreasing the viability and disturbing the morphology of U373MG cells.

3-Bromopyruvate antagonizes effects of lactate and pyruvate, synergizes with citrate and exerts novel anti-glioma effects.

Oxidative stress-energy depletion therapy using oxidative stress induced by D-amino acid oxidase (DAO) and energy depletion induced by 3-bromopyruvate (3BP) was reported recently (El Sayed et al., Cancer Gene Ther., 19, 1-18, 2012). Even in the presence of oxygen, cancer cells oxidize glucose preferentially to produce lactate (Warburg effect) which seems vital for cancer microenvironment and progression. 3BP is a closely related structure to lactate and pyruvate and may antagonize their effects as a novel mechanism of its action. Pyruvate exerted a potent H(2)O(2) scavenging effect to exogenous H(2)O(2), while lactate had no scavenging effect. 3BP induced H(2)O(2) production. Pyruvate protected against H(2)O(2)-induced C6 glioma cell death, 3BP-induced C6 glioma cell death but not against DAO/D-serine-induced cell death, while lactate had no protecting effect. Lactate and pyruvate protected against 3BP-induced C6 glioma cell death and energy depletion which were overcome with higher doses of 3BP. Lactate and pyruvate enhanced migratory power of C6 glioma which was blocked by 3BP. Pyruvate and lactate did not protect against C6 glioma cell death induced by other glycolytic inhibitors e.g. citrate (inhibitor of phosphofructokinase) and sodium fluoride (inhibitor of enolase). Serial doses of 3BP were synergistic with citrate in decreasing viability of C6 glioma cells and spheroids. Glycolysis subjected to double inhibition using 3BP with citrate depleted ATP, clonogenic power and migratory power of C6 glioma cells. 3BP induced a caspase-dependent cell death in C6 glioma. 3BP was powerful in decreasing viability of human glioblastoma multiforme cells (U373MG) and C6 glioma in a dose- and time-dependent manner.

D-amino acid oxidase gene therapy sensitizes glioma cells to the antiglycolytic effect of 3-bromopyruvate.

Glioma tumors are refractory to conventional treatment. Glioblastoma multiforme is the most aggressive type of primary brain tumors in humans. In this study, we introduce oxidative stress-energy depletion (OSED) therapy as a new suggested treatment for glioblastoma. OSED utilizes D-amino acid oxidase (DAO), which is a promising therapeutic protein that induces oxidative stress and apoptosis through generating hydrogen peroxide (H2O2). OSED combines DAO with 3-bromopyruvate (3BP), a hexokinase II (HK II) inhibitor that interferes with Warburg effect, a metabolic alteration of most tumor cells that is characterized by enhanced aerobic glycolysis. Our data revealed that 3BP induced depletion of energetic capabilities of glioma cells. 3BP induced H2O2 production as a novel mechanism of its action. C6 glioma transfected with DAO and treated with D-serine together with 3BP-sensitized glioma cells to 3BP and decreased markedly proliferation, clonogenic power and viability in a three-dimensional tumor model with lesser effect on normal astrocytes. DAO gene therapy using atelocollagen as an in vivo transfection agent proved effective in a glioma tumor model in Sprague-Dawley (SD) rats, especially after combination with 3BP. OSED treatment was safe and tolerable in SD rats. OSED therapy may be a promising therapeutic modality for glioma.

Prognostic significance of cyclooxygenase-2, epidermal growth factor receptor 1, and microvascular density in gastric cancer.

Gastric cancer remains a significant global health burden with poor treatment outcome. New treatment modalities that target inflammation, proliferation, and angiogenesis have been used in various cancers, including gastric cancer. We sought to study the pattern of expression of two important proteins, cyclooxygenase-2 and epidermal growth factor receptor, and their association with microvascular density, clinicopathological features, and survival in Arab Omani patients with gastric cancer. Formalin-fixed, paraffin-embedded tumors were studied by immunohistochemistry using monoclonal antibodies to cyclooxygenase-2, epidermal growth factor receptor, and CD34. The immunohistochemical results were correlated with clinicopathological features and survival. In our study population, we found a male/female ratio of 72:43, a median age of 59 years, stage III and IV incidence of 66.9%, and a median follow-up of 96 months. Positive expression rates of cyclooxygenase-2 and epidermal growth factor receptor were 89.6 and 23.5%, respectively. The median microvascular density value was 52.5. When this value was determined as the cut-off point, 50% of patients were found to have high microvascular density. Epidermal growth factor receptor over-expression correlated with high microvascular density values, advanced lymph node involvement (N3), and TNM stage presentation (III and IV). Similarly, lymph node involvement was associated with cyclooxygenase-2 over-expression and high microvascular density. Univariate analysis showed that epidermal growth factor receptor over-expression, pathological T3 and T4 disease, and overall stage III and IV disease were adverse prognostic factors. On multivariate analysis using a Cox regression model, expression of epidermal growth factor receptor, and advanced TNM stage were significant adverse prognostic factors for overall survival. Expression of epidermal growth factor receptor in Arab Omani patients with gastric cancer correlates with aggressive tumor characteristics and is an independent prognostic factor. Further clinical studies are needed to evaluate the utility of epidermal growth factor receptor immunohistochemistry as a tool for gastric cancer treatment.

Degradation of natural rubber by Achromobacter sp. NRB and evaluation of culture conditions.

A natural rubber degrading candidate was isolated from a soil sample from Aswan, Egypt. The strain was able to grow on natural rubber as a sole source for carbon and energy. According to its degradation behavior, it grew adhesively and in direct contact with the rubber substrate and led to disintegration of the material during cultivation. Furthermore, this strain was not able to form a clear zone (translucent halos) around bacterial colonies after cultivation on NR latex plates. Taxonomic analysis of the strain based on partial 16S rRNA similarity examinations indicated that bacterial candidate belongs to genus Achromobacter sp. Schiff's reagent staining tests performed during cultivation of the strain on NR latex gloves of different sizes, treated or nontreated, revealed that the strain was able to colonize the rubber surface. Formation of bacterial films and occurrence of compounds containing aldehyde groups during cultivation was observed. The tested strain showed a higher colonization efficiency on small or treated pieces of NR latex gloves, while a lower colonization efficiency was recognized when grown on large or nontreated NR latex gloves. Plackett-Burman experimental design, based on numerical modeling, was applied to evaluate the significance of culture conditions affecting natural rubber degradation by the bacterial candidate. Eleven variables through fourteen trials were studied simultaneously. Based on rubber mineralization data, the highest positive variables affecting rubber degradation were NR granules, K2HPO4, Na-succinate and NH4Cl, while MgSO4 x 7H2O and KH2PO4 were the lowest significant variables.

Cardiac and ocular manifestations in Egyptian patients with mucopolysaccharidoses.

Cardiac and ocular manifestations were evaluated in 21 patients clinically suspected of mucopolysaccharidosis. After electrophoresis analysis of urinary glycoaminoglycans, 3 patients were excluded because their results did not correlate with any known type of mucopolysaccharidosis. Echocardiography revealed abnormal findings in 11 patients (61.1%). The mitral valve was the most commonly affected valve; 7 patients (38.9%) had thickened mitral valve and 6 had mitral regurge. Corneal opacities were found in 3 patients (16.7%) and progressive increase in intraocular pressure in 1 patient (5.6%), while fundus examination showed early optic atrophy in 1 patient (5.6%) and bilateral papilloedema in 2 patients (11.1%).

Cardiac and ocular manifestations in Egyptian patients with mucopolysaccharidoses

Cardiac and ocular manifestations were evaluated in 21 patients clinically suspected of mucopolysaccharidosis. After electrophoresis analysis of urinary glycoaminoglycans, 3 patients were excluded because their results did not correlate with any known type of mucopolysaccharidosis. Echocardiography revealed abnormal findings in 11 patients [61.1%]. The mitral valve was the most commonly affected valve; 7 patients [38.9%] had thickened mitral valve and 6 had mitral regurge. Corneal opacities were found in 3 patients [16.7%] and progressive increase in intraocular pressure in 1 patient [5.6%], while fundus examination showed early optic atrophy in 1 patient [5.6%] and bilateral papilloedema in 2 patients [11.1%]

Effect of fluoride application on specular reflectance and stain potential of unfilled and photocured microfilled resin veneering materials.

A laboratory study was conducted to determine the effect of application of four types of fluoride solutions commonly used and administered by dentists on the specular reflectance and staining potential of photocured and regular unfilled resin veneering materials. The fluoride solutions used were: (1) 1.23% acidulated phosphate fluoride gel (APF) gel, (2) 0.4% stannous fluoride gel, (3) 0.2% sodium fluoride solution and (4) .05% sodium fluoride solution. Specular and diffuse reflectance using scanning spectrophotometer were carried out for the fluoride treated samples and the control untreated samples before and after staining. The results revealed that the (APF) gel, produced the highest surface roughness and staining ability followed by the stannous fluoride solution for the both tested veneering materials. The sodium fluoride mouth wash solutions (0.2% and 0.05%) produced the least effect. So, on the bases of these results, caution should be taken in utilization of fluoride treatment in patients with prosthesis containing resin veneering material.

Biological influence of some crown and bridge restorative materials finished and polished by different techniques.

Fixed restorations should satisfy certain biologic requirements and they must not be injurious to the surrounding living tissues as pulp, periodontal ligament, alveolar bone and gingiva. It is best to terminate preparations above the gingival margin but for retention and esthetics considerations the margins of the fixed restorations could be placed subgingivally. In recent years, the biologic effects of dental restorative materials on the gingiva and periodontal tissues have been better appreciated. A rough surface restoration attracts and retains bacterial plaque and irritates the surrounding soft tissues which is injurious to the living supporting structure of the abutments.

Daily and seasonal activities of some sandflies from Surrugia village, Khartoum, Sudan.

The present study is concerned with four species of phlebotomine sandflies prevailing in Khartoum area between the years 1984 and 1987. Flies studied were Phlebotomus papatasi, Sergentomyia antennata, S. clydei and S. schewtzi. The indoor and outdoor daily rhythmic and biting activities were determined during the transmission season for both males and females P. papatasi. Peaks of daily activities and the time at which man is at greatest risk were determined. For each year the monthly relative population densities, populations structure and seasonal changes of sandflies were studied, in comparison with the pooled data of the four years. Seasonal density changes were correlated with temperature, relative humidity and rainfall prevailing in the area.

Psychiatric diagnostic categories in Saudi Arabia.

This study involves 324 new cases referred to the Psychiatric Department of King Faisal University, Dammam, Saudi Arabia, over a period of 6 months. Men outnumbered women, which is in contrast to most Western studies. There was a preponderance in the younger age groups. The interaction of cultural factors and the rapid urbanization of the Saudi society may to some extent explain the pattern.

Colorimetric determination of certain phenol derivatives in pharmaceutical preparations.

Simple colorimetric methods are reported for determining both acetaminophen and oxyphenbutazone. These methods are based on coupling between the phenolic compound and the diazonium salts of both sulfanilic acid and p-nitroaniline; the optimum conditions for the reactions were carefully studied. For acetaminophen, the reaction products with diazosulfanilic acid and diazo-p-nitroaniline show maximum absorbance at 480 and 425 nm, respectively. The mean percentage recoveries for authentic samples were 99.5 +/- 1.1 and 100.6 +/- 0.66, respectively (P = 0.05). For oxyphenbutazone, the obtained colors showed maxima at 385 nm with diazosulfanilic acid and 490 nm with diazo-p-nitroaniline reactions. The mean percentage recoveries for authentic samples were 99.8 +/- 0.27 and 100.1 +/- 0.57, respectively (P = 0.05). The proposed methods were successfully applied to the analysis of commercial preparations; results were statistically compared with those of other methods.