Influence of 120 kDa Pyruvate:Ferredoxin Oxidoreductase on Pathogenicity of Trichomonas vaginalis

Trichomonas vaginalis is a flagellate protozoan parasite and commonly infected the lower genital tract in women and men. Iron is a known nutrient for growth of various pathogens, and also reported to be involved in establishment of trichomoniasis. However, the exact mechanism was not clarified. In this study, the author investigated whether the 120 kDa protein of T. vaginalis may be involved in pathogenicity of trichomonads. Antibodies against 120 kDa protein of T. vaginalis, which was identified as pyruvate:ferredoxin oxidoreductase (PFOR) by peptide analysis of MALDI-TOF-MS, were prepared in rabbits. Pretreatment of T. vaginalis with anti-120 kDa Ab decreased the proliferation and adherence to vaginal epithelial cells (MS74) of T. vaginalis. Subcutaneous tissue abscess in anti-120 kDa Ab-treated T. vaginalis-injected mice was smaller in size than that of untreated T. vaginalis-infected mice. Collectively, the 120 kDa protein expressed by iron may be involved in proliferation, adhesion to host cells, and abscess formation, thereby may influence on the pathogenicity of T. vaginalis.

Low iodine diet does not improve the efficacy of radioiodine for the treatment of Graves’ disease

Objective Consuming a low-iodine diet (LID) is a widely accepted practice before administering radioiodine (131I) to evaluate and to treat thyroid disease. Although this procedure is well established for the management of patients with differentiated thyroid cancer, its use in patients with benign disease is unclear. So, we aimed to evaluate the influence of a LID on the outcome in patients with Graves’ disease (GD) treated with131I. Subjects and methods We evaluated 67 patients with GD who were divided into 2 groups: one group (n = 31) consumed a LID for 1-2 weeks, and the second group (n = 36) was instructed to maintain a regular diet (RD). Results The LID group experienced a 23% decrease in urinary iodine after 1 week on the diet and a significant 42% decrease after 2 weeks on the diet. The majority (53%) of the patients in the LID group had urinary iodine levels that were consistent with deficient iodine intake. However, there was no difference in the rate of hyperthyroidism’s cure between the LID and the RD groups 6 months after 131I therapy. Furthermore, the therapeutic efficacy did not differ in patients with varying degrees of sufficient iodine intake (corresponding urinary iodine levels: < 10 μg/dL is deficient; 10-29.9 μg/dL is sufficient; and > 30 μg/dL is excessive). Conclusion In the present study, we demonstrated that although a LID decreased urinary iodine levels, those levels corresponding with sufficient or a mild excess in iodine intake did not compromise the therapeutic efficacy of131I for the treatment of GD.

Zinc and low-dose of cadmium protect sertoli cells against toxic-dose of cadmium: the role of metallothionein

The impact of cadmium [Cd] on male infertility may be related to the interaction with metal-binding proteins known as metallothioneins [Mts]. Trace elements like zinc [Zn] have protective effects on testicular damage induced by Cd. We determined the effect of Zn and low-dose Cd pre-treatment on the expression of Mt1 and Mt2 genes on testicular Sertoli cells. The cultured TM4 mouse sertoli cells were treated with 50 micro M ZnSO4 [Zn pre-treated group; ZnPG], 2 micro M CdCl2 [Cd pre-treated group; CdPG], or distilled water [DW pre-treated group; DWPG]. After 18 hour, all of these groups were exposed to 100 micro M CdCl2 for different periods of time [1, 2, 3, and 6 hours]. There was also a control group for all three groups, which was treated only with distilled water [without Cd or Zn pre-treatment]. Cellular viability, Zn and Cd concentrations and gene expression were assessed by MTT, atomic absorption spectrometry and real time PCR methods, respectively. The expression of Mt1 and Mt2 genes in ZnPG, CdPG, and DWPG was greater than the control group [p=0.02 and p=0.01, respectively]. Cd concentrations in CdPG and DWPG were greater than the control group [p=0.00]. Expression of both genes in ZnPG and CdPG increased after 3 hours of treatment and Cd concentration decreased simultaneously, which was more obvious in ZnPG. Zn and short term low-dose Cd pre-treatment might reduce the adverse effects of Cd by increasing expression of Mts genes in Sertoli cells. The protective effect of Zn was stronger than Cd

Protective effect of zinc over lead toxicity on testes

To determine the effects of lead and zinc on testes. Randomized control trial. Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi, from August 2003 to December 2005. Sixty adult [90 days old] albino rats were obtained from animal house JPMC for the study and divided into 3 groups. Group A received injection normal saline 1 cc intraperitoneally daily for 8 weeks. Group B received lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily. Group C received zinc chloride in a dose of 1 mg/kg body weight before half an hour of injection of lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily so that to provide pre-treatment. On the day of completion of treatment the animals were sacrificed testes removed and fixed in Bouins fluid. Testes were dehydrated in the ascending strength of alcohol, 5 micro m thick sections were cut and stained with PAS Iron Hematoxylin. Student's t-test was used for statistical analysis with significance at p<0.05. The mean diameter of seminiferous tubule was 291.91 +/- 1.18, 198.53 +/- 1.67 and 288.77 +/- 1.11 micro m in groups A, B and C respectively. Diameter of seminiferous tubules decreased by 31.99% in group B [p<0.001; CI 89.023 to 97.736] as compared group A and while group B comparing with group C, the diameter of seminiferous tubules was decreased by 31.25% [p-value=0.076; CI-94.264 to-86.203]. Mean thickness of germinal epithelium was 96.19 +/- 1.01, 50.69 +/- 1.20 and 94.94 +/- 0.54 micro m in groups A, B and C respectively. Thickness of germinal epithelium decreased by 47.30 in group B [P<0.001; CI 42.503 to 48.496] as compared to group A and while comparing group B with group C, the thickness of germinal epithelium was decreased by 46.61% [p=-44.25; CI-46.704 to-41.787]. Zinc prevented toxic effects of lead on germinal epithelium in the albino rats

Amelioration of altered antioxidant status and membrane linked functions by vanadium and Trigonella in alloxan diabetic rat brains.

Trigonella foenum graecum seed powder (TSP) and sodium orthovanadate (SOV) have been reported to have antidiabetic effects. However, SOV exerts hypoglycemic effects at relatively high doses with several toxic effects. We used low doses of vanadate in combination with TSP and evaluated their antidiabetic effects on anti-oxidant enzymes and membrane-linked functions in diabetic rat brains. In rats, diabetes was induced by alloxan monohydrate (15 mg/100 g body wt.) and they were treated with 2 IU insulin, 0.6 mg/ml SOV, 5% TSP and a combination of 0.2 mg/ml SOV with 5% TSP for 21 days. Blood glucose levels, activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), Na+/K+ ATPase, membrane lipid peroxidation and fluidity were determined in different fractions of whole brain after 21 days of treatment. Diabetic rats showed high blood glucose (P less than 0.001), decreased activities of SOD, catalase and Na+/K+ ATPase (P less than 0.01, P less than 0.001 and P less than 0.01), increased levels of GPx and MDA (P less than 0.01 and P less than 0.001) and decreased membrane fluidity (P less than 0.01). Treatment with different antidiabetic compounds restored the above-altered parameters. Combined dose of Trigonella and vanadate was found to be the most effective treatment in normalizing these alterations. Lower doses of vanadate could be used in combination with TSP to effectively counter diabetic alterations without any toxic effects.

Complicaciones y sus factores asociados en la nutrición parenteral total en neonatos: Servicio de Neonatología Hospital Central de San Cristóbal julio-septiembre 2002 / Complications and associated factors in total parenteral nutrition in neonates: Department of Neonatology Hospital Central de San Cristóbal july-september 2002

La nutrición parenteral (NP) es una técnica adecuada, pero no fisiológica, que permite administrar macro y micronutrientes y calorías directamente a través de la circulación sistémica. Sin embargo, aunque la NPT sea un método adecuado de soporte nutricional, no está exento de complicaciones. Algunos autores, han descrito las complicaciones de tipo metabólicas e infecciosas como las más frecuentes en el período neonatal y otros estudios han destacado además diversas complicaciones de tipo mecánico, relacionadas con la colocación de los catéteres. Determinar las complicaciones que se presentan en los recién nacidos que ameritan nutrición parenteral, hospitalizados en la Unidad de Recién Nacidos y en la Unidad de Patología Neonatal del Hospital Central de San Cristóbal e identificar los factores de riesgo asociados. Se implementó un estudio prospectivo, longitudinal, descriptivo y observacional, con un intervalo de tres meses para selección de la muestra. Durante este tiempo, se obtuvieron muestras de 36 pacientes, de los cuales todos fueron estudidos. El criterio final de inclusión para cada paciente lo constituyó la indicación de la NPT. El tiempo promedio de administración fue de 8 días; 26 (72 por ciento) de los neonatos eran prematuros. En 26 por ciento (72 por ciento) se encontraron complicaciones y de ellas las más frecuentes fueron las metabólicas. No se encontró correlación significativa entre los factores de riesgo y la aparición de complicaciones por administración de NPT. No se encontró una asociación significativa entre los factores de riesgo y las complicaciones, aunque la mayor parte de neonatos complicados resultaron prematuros con indicación prolongada de NPT. Es necesaria mayor vigilancia en todos los procedimientos relacionados con la administración de NPT, en especial para pacientes prematuros y en los que se administre por tiempo prolongado.

Effect of trace elements on surface hydrophobicity and adherence of Escherichia coli to uroepithelial cells.

Trace elements have significant effect on the physiology of bacteria. Variation in the concentration of trace elements may affect the expression of virulence by microorganisms. The effect of trace elements on hydrophobicity and adherence of E.coli to uroepithelial cells was studied. Increasing concentrations of Ca2+, Mg2+, Fe3+ and Zn2+ significantly decreased the surface hydrophobicity. Toxic trace elements like Co2+, Cu2+, Mn2+ and Ni2+ did not alter surface hydrophobicity. With regards to adherence of E.coli to uroepithelial cells, only Mg2+ had significant effect. Toxic trace elements decreased the rate of cell adherence. The pathogenic strains of E.coli showed higher surface hydrophobicity and better cell adherence compared to the nonpathogenic strains. There was good correlation between surface hydrophobicity and cell adherence at higher concentrations (0.1 to 0.2mM) of Fe2+ and Zn2+. The results indicated that trace elements can significantly affect surface hydrophobicity and adherence of E.coli to uroepithelial cells. Such effect may have a significant impact on the initial stages of bacterial infection.

Antioxidantes: mitos y realidades / Antioxidants: myths and reallity

La homeostasis de los seres vivos aeróbicos se ve constantemente amenazada por la formación de moléculas químicamente inestables y altamente reactivas llamadas radicales libres. Estos pueden generarse por agresores metabólicos endógenos (metabolismo celular) o exógenos, como el tabaco, el ozono y la radiación ultravioleta. Se les relaciona con una serie de condiciones patológicas, como la carcinogénesis, la aterosclerosis y el envejecimiento tisular. Los antioxidantes son sustancias que al interactuar con estos radicales libres previenen o demoran su acción deletérea. En la dieta se encuentran diversos compuestos que pueden contribuir a la modulación interna de los antioxidantes, apartándolos en forma directa o como cofactores. Es importante conocer estos antioxidantes dietarios, saber sus requerimientos mínimos y los potenciales riesgos por uso inapropiado

Selenium protects against ischemia-reperfusion-induced gastric lesions in rats

Recent studies have shown that selenium afforded protection against ethanol and stress-induced gastric lesions in rats. The present study was undertaken to investigate the effect of selenium on ischemia-reperfusion-induced gastric injuries in which rats were subjected to 30 minutes of ischemia in the presence of 100 mtM HCI and a reperfusion for 60 minutes duration. Intraluminal bleeding was assessed macroscopically and gastric lesions were graded microscopically under an inverted microscope. Nonprotein sulphydryl levels were measured spectrophotometrically. The severity of gastric lesions, intraluminal bleeding as well as the depletion of nonprotein sulphydryls during the reperfusion periods was significantly different from that of control. Pretreatment with selenium [0.125-2.0 mg/kg, intraperitoneally] 30 minutes before the ischemia-reperfusion, dose-dependently attenuated the gastric lesions, reduced the severity of intraluminal bleeding and prevented the depletion of nonprotein sulphydryls in the stomach. These results suggest that the gastric protection effect of selenium may be due to its antioxidant properties. Furthermore, endogenous nonprotein sulphydryls may play a significant role in the protective mechanisms of selenium

Role of zinc in repair

Zinc is potent catalyst necessary for tissue repair and healing. Its administration leading to correction of lowered serum levels and acceleration of wound healing has improved the success rate of our surgical repair of Vesicovaginal Fistula [VVF] and played an important role in reducing its rate of recurrence

Effect of trace metals on synthesis of exoproteins and exotoxins by Staphylococcus aureus.

Staphylococcus aureus did not grow in chemically defined medium completely free of trace metals. At low concentrations all the trace metals showed stimulating effect on growth and exoprotein production. Increasing concentrations of Ca2+ and Mg2+ were growth stimulatory whereas Co2+, Cu2+, Fe3+, Mn2+, Ni2+ and Zn2+ were inhibitory. The amount of exoprotein and haemolytic exotoxins produced in relation to final viable count increased with increasing concentrations of growth inhibitory trace metals whereas it decreased with increasing concentrations of Ca2+ and Mg2+. Trace metals did not show significant influence on amount of haemolytic exotoxins produced in relation to total exoproteins. The results indicate presence of a common regulatory mechanism for all types of exoproteins produced by S. aureus.