The potential roles of bacteria to improve radiation treatment outcome

Many combined therapies have been proposed to enhance radiotherapy outcome, but they have several limitations. As a new feasible strategy, combination of radiotherapy with bacteria showed a significant positive impact on the tumor treatment and metastasis inhibition. Although probiotic bacteria and radiotherapy alone can be effective in the treatment of different cancers, the combination of these two therapies seems to enhance therapeutic outcome and is cost-effective. Bacterial cells can act as therapeutic/gene/drug delivery vehicles as well as theranostic agents. In this communication, we reviewed current evidences, studies, suggestions, and future-based directions on combination of radiotherapy and bacteria. In another sections, an overview on tumor hypoxia, bacteria in cancer therapy, and combination of radiotherapy and bacteria is presented. A brief overview on trials and animal studies which used bacteria to protect normal tissues against radiotherapy-induced complications is also included (AU)

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The potential roles of bacteria to improve radiation treatment outcome.

Many combined therapies have been proposed to enhance radiotherapy outcome, but they have several limitations. As a new feasible strategy, combination of radiotherapy with bacteria showed a significant positive impact on the tumor treatment and metastasis inhibition. Although probiotic bacteria and radiotherapy alone can be effective in the treatment of different cancers, the combination of these two therapies seems to enhance therapeutic outcome and is cost-effective. Bacterial cells can act as therapeutic/gene/drug delivery vehicles as well as theranostic agents. In this communication, we reviewed current evidences, studies, suggestions, and future-based directions on combination of radiotherapy and bacteria. In another sections, an overview on tumor hypoxia, bacteria in cancer therapy, and combination of radiotherapy and bacteria is presented. A brief overview on trials and animal studies which used bacteria to protect normal tissues against radiotherapy-induced complications is also included.

Seroepidemiology of herpes simplex virus type 1 and 2 in northern iran.

BACKGROUND: Herpes simplex virus (HSV) type 1 and 2 are common infectious agents worldwide. Data on prevalence of HSV-1 and HSV-2 infection are limited in Asia, especially in Iran. The aim of this study was to determine the seroprevalence of HSV type 1 and 2 based on age, gender, marital status, education, living area, job, symptoms and history of disease variables. METHODS: The study population included 800 randomly selected persons from laboratories in Gilan Province, Iran, from 2010 to 2011. Demographic data gathered by a well-designed questionnaire and for serological studies, blood samples were collected and centrifuged. ELISA HSV-1, 2 and HSV-2 specific ELISA kits were used to determine IgG type specific antibodies in sera samples. Person's chi-square test was applied to compare HSV-1 and HSV-2 seropositivities. RESULTS: HSV-1 and HSV-2 IgG antibodies were positive in 467 (58.4%) and 28 (3.5%) subjects, respectively. There was significant correlation between age, marital status, job, symptoms, history of disease and HSV seroprevalence (P<0.05). CONCLUSION: Our findings were in agreement with prior studies in which HSV-1 infections was more prevalent than HSV-2 and seropositivity increased with age.

Simultaneous and rapid differential diagnosis of Mycoplasma genitalium and Ureaplasma urealyticum based on a polymerase chain reaction-restriction fragment length polymorphism.

OBJECTIVES: The aim of this investigation was to simultaneously detect and differentiate Mycoplasma genitalium and Ureaplasma urealyticum in female patients suffering from genital complications by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). MATERIALS AND METHODS: Genital swabs were taken from 210 patients. They were transported to the laboratory in phosphate-buffered saline. For PCR, samples were analysed with genus-specific MyUu-R and MyUu-F primers. This primer set, which was originally designed in our laboratory, amplified a 465 bp fragment (M. genitalium) and a 559 bp fragment (U. urealyticum). Samples containing a band of the expected sizes for the Mycoplasma strains were subjected to digestion with a restriction endonuclease enzyme of TaqI and Cac8I. RESULTS: Of the 210 samples, a total of 100 (47.6%) samples were found to be positive for Mycoplasmas (seven M. genitalium isolates, 3.3%; and 89 U. urealyticum isolates, 42.4%), and coinfections with both species were detected in four samples (1.9%). The PCR-RFLP results showed that M. genitalium and U. urealyticum are different by enzyme patterns. CONCLUSION: PCR-RFLP offers a rapid and easily applicable protocol to simultaneous detection and differentiation of M. genitalium and U. urealyticum from clinical samples when specific primers and restriction enzymes are used.

In vitro inhibition of Helicobacter pylori urease with non and semi fermented Camellia sinensis.

PURPOSE: Helicobacter pylori is the etiological agent in duodenal and peptic ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. This study was conducted to evaluate the effect of Camellia sinensis extracts on the urease enzyme that is a major colonization factor for H. pylori. METHODS: Minimum inhibitory concentrations of nonfermented and semifermented C. sinensis methanol: water extracts were assessed by broth dilution method. Examination of the urease function was performed by Mc Laren method, and urease production was detected on 12% SDS polyacrylamide gel electrophoresis from whole cell and membrane bound proteins. RESULTS: Both extracts had inhibitory effects against H. pylori and urease production. At a concentration of 2.5 mg/ml of nonfermented extract and 3.5 mg/ml of semifermented extract the production of Ure A and Ure B subunits of the urease enzyme were inhibited completely. A concentration of 4 mg/ml of nonfermented and 5.5 mg/ml of semifermented extract were bactericidal for H. pylori. CONCLUSIONS: C. sinensis extracts, especially the nonfermented, could reduce H. pylori population and inhibit urease production at lower concentrations. The superior effect of nonfermented extract is due to its rich polyphenolic compounds and catechin contents.

Comparison of heat shock response in Brucella abortus and Brucella melitensis.

Heat shock protein (hsp) is highly conserved, that serves a wide range of function in protein folding and transport. It protect from various type of stress including heat shocks. However, it is well known that the virulence of B. melitensis is more than B. abortus, but there is not any strong evidence to verify it. For this purpose, in refer to potent antigenicity of hsps in various infectious as well as some hsp molecules act as potent activator of macrophage (danger signal), we hypothesized that difference in virulence between B. abortus and B. melitensis may be originated from difference in pattern of response to heat shock induced by high degree of fever that usually present in brucellosis. To this end, five B. abortus and five B. melitensis strains isolated from cows and human, were subjected to 39, 40 and 42 degrees C heat shocks. The bacterial whole cell proteins were extracted and resolved by SDS-PAGE. Western blotting was used to detect antibody production against the extracted bacterial proteins especially hsp60 in both control and patient sera. SDS-PAGE gels revealed protein bands mainly in the range of 10-100 kDa. The amounts of a 60 kDa protein band (hsp60) was significantly enhanced following heat shock at 42 degrees C in relation to the unheated cells in both bacterial species. The heat shock responses in B. abortus and B. melitensis point to the higher production of a 60 kDa protein (hsp60) in both bacterial species, especially in B. abortus. It seems that, lower hsp60 production by B. melitensis would induce a relatively much lower immune response against the bacterium leading to its greater virulence potentials; the sera from Brucellosis patients reacted with several of these cell derived protein bands in western blots, none of which were reactive with sera from healthy individuals. The western blot protein bands showed striking differences. This observation points to the immunogenic properties of hsps, specially the overwhelming response to hsp-60. Therefore, hsp-60 can be a good antigenic candidate for engineering subunit vaccine against Brucella, as well as for ELISA test development.

Nutritional requirements for synthesis of heat-stable enterotoxin by Yersinia enterocolitica.

A defined medium that supported the growth of and synthesis of heat-stable enterotoxin (YST) by clinical isolates of Yersinia enterocolitica at levels equivalent to those observed in a complex Trypticase soy broth-0.6% yeast extract medium was developed. The defined medium contained four amino acids (L-methionine, L-glutamic acid, glycine, and L-histidine), inorganic salts, N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffer, and potassium gluconate as the carbon source. Methionine was required for growth by most strains of Y. enterocolitica used in this study; thus, it was not possible to determine whether it was also required for the synthesis of YST. The other 17 amino acids commonly found in proteins did not stimulate the synthesis of YST when added to the defined medium. The yield of YST observed with other carbon sources fermented by Y. enterocolitica ranged from 4- to 26-fold lower than that obtained with potassium gluconate. The divalent cations Ca2+ and Mn2+ had no effect on the synthesis of YST; however, concentrations of Fe2+ above 10 microM inhibited the synthesis of the enterotoxin. The addition of a mixture of pyrimidines containing thymine, cytosine, and uracil, each at a concentration of 2.0 mM, stimulated the synthesis of YST by 10 to 15%, whereas a mixture of adenine and guanine, each at a similar concentration, inhibited the synthesis of YST. Vitamins had no effect on the amounts of YST produced by Y. enterocolitica strains grown in the defined medium.(ABSTRACT TRUNCATED AT 250 WORDS)