High prevalence of mouse mammary tumor virus-like gene sequences in breast cancer samples of Iranian women

Mouse mammary tumor virus (MMTV) is considered to be responsible for breast tumor development in mice. In several instances sequences homologous to the genome of this virus have been reported in human breast cancer samples.

Here we aimed to evaluate MMTV involvement in human breast cancer development. DNA was extracted from 118 formalin fixed and paraffin embedded malignant (n = 59) and benign (n = 59) breast lesions. Using two sets of outer and inner MMTV-like envelope specific primers, in a nested PCR setup, MMTV genome was detected in 19 samples out of 59 (%32.2) cases of breast carcinomas, while in non-malignant breast tissue samples, only 3 samples out of 59 (%5) were positive. The difference was statistically highly significant (p < 0.001). Alignment of PCR amplified sequences with BR6, GR and C3H mouse mammary tumor virus strains emerged to be around 99% identical which is indicative of tumor tissue infection by an exogenous mouse MMTV genome.     

Internalin B is essential for adhesion and mediates the invasion of Listeria monocytogenes into human endothelial cells

Listeria monocytogenes causes rhombencephalitis in humans and animals and also affects the fetus in utero , causing disseminated sepsis. In both instances, the infection occurs by the crossing of endothelial cells lining a physiological barrier, the blood–brain barrier or the transplacental barrier. In this study, the ability of L. monocytogenes wild-type EGD to invade human umbilical vein endothelial cells (HUVECs) was evaluated using wild-type bacteria and isogenic Listeria mutants. Here, we show that invasion of HUVECs by L. monocytogenes is dependent on the expression of the internalin B gene product. This was demonstrated in several ways. First, L. monocytogenes strains lacking the inl B gene did not invade HUVECs. Secondly, avid invasion was obtained when a strain deleted for inl AB was complemented with a plasmid harbouring inl B only, whereas strains expressing inl A did not enter HUVECs. Thirdly, entry of wild-type EGD could be blocked effectively with antibodies to InlB. Fourthly, cell binding assays and flow cytometry with HUVECs showed binding of purified InlB, but not InlA, suggesting a tropism of InlB for this cell type. Finally, physical association of purified native InlB with the surface of non-invasive mutants dramatically increased their ability to invade HUVECs. In laser-scanning confocal microscopy, binding of InlB was observed as focal and localized patches on the cell surface of HUVECs. Qualitative examination of the entry process by scanning electron microscopy revealed that both wild-type EGD and a recombinant strain overexpressing only InlB enter HUVECs in a similar fashion. The entry process was polarized, involved single bacteria and occurred over the entire surface of endothelial cells.     

Genetically different clonal isolates of Trichomonas gallinae, obtained from the same bird, can vary in their drug susceptibility, an in vitro evidence

Trichomonas gallinae is a flagellated protozoon which parasitizes in the upper digestive tract of different birds, especially columbiformes (doves and pigeons) and falconiformes. The parasite is also a common inhabitant of the crop of psittacine birds and is frequently detected in budgerigars. The lesions associated with T. gallinae infection of the upper digestive tract range from mild inflammation of the mucosa to large caseous lesions that block the lumen of the oesophagus. Nitroimidazoles are considered to be the drugs of choice for the treatment of trichomonosis. However, only a few studies report the existence of resistant strains of T. gallinae to these drugs. Thus, in the present investigation cloned cultures of T. gallinae obtained from budgerigars and pigeons were analysed for the first time for their in vitro susceptibilities against four 5′-nitroimidazole derivates, including metronidazole, dimetridazole, ronidazole and ornidazole. Significantly different minimal lethal concentrations (MLCs) were observed for them against all four drugs. The lowest MLCs revealed the Trichomonas isolates obtained from two budgerigars, ranging from 2.0 ± 0.3 to 3.0 ± 0.7 μg/ml for metronidazole and dimetridazole, and from 2.0 ± 0.6 to 6.7 ± 1.7 μg/ml for ornidazole and ronidazole. Contrary to this, the highest MLCs were recorded for one Trichomonas isolate obtained from a pigeon, ranging from 83.3 ± 6.7 (for dimetridazole and ronidazole) to 103.3 ± 3.3 μg/ml (for metronidazole and ornidazole). The data obtained for the resistance testing were further compared with already available genetic data of the small subunit rRNA gene sequences and ITS-1, 5.8S rRNA and ITS-2 sequences, indicating a certain correlation between in vitro results and strain relationships.     

Demographic and Clinical Features of Dengue Fever in Pakistan from 2003–2007: A Retrospective Cross-Sectional Study

Background

Demographic features of dengue fever have changed tremendously in Pakistan over the past two decades. Small scale studies from all over the country have reported different aspects of individual outbreaks during this time. However, there is scarcity of data looking at the overall trend of dengue virus infection in the country. In this study, we examined annual trends, seasonality, and clinical features of dengue fever in the Pakistani population.

Methods

Demographic information and dengue IgM status of all patients tested for dengue IgM antibody at Aga Khan University Hospital from January 2003 to December 2007 were analyzed to look for trends of IgM-positive cases in Pakistan. In addition, clinical and biochemical parameters were abstracted retrospectively from medical records of all patients hospitalized with IgM-proven dengue fever between January 2006 and December 2007. These patients were categorized into dengue fever and dengue hemorrhagic fever according to the WHO severity grading scale.

Results

Out of a total of 15040 patients (63.2% male and 36.8% female), 3952 (26.3%) tested positive for dengue IgM antibody. 209 IgM proven dengue patients were hospitalized during the study period. During 2003, IgM positive cases were seen only during the months of July-December. In contrast, such cases were detected throughout the year from the 2004–2007. The median age of IgM positive patients decreased every year from 32.0 years in 2003 to 24.0 years in 2007 (p<0.001). Among hospitalized patients, nausea was the most common presenting feature found in 124/209 (59.3%) patients. Children presented with a higher median body temperature than adults (p = 0.010). In addition, neutropenia was seen more commonly in children while raised serum ALT levels were seen more commonly in adults (both p = 0.006). While a low total white cell count was more common in patients with dengue fever as compared to Dengue Hemorrhagic Fever (p = 0.020), neutropenia (p = 0.019), monocytosis (p = 0.001) and raised serum ALT level (p = 0.005) were observed more commonly in the latter group.

Conclusions

Dengue virus is now endemic in Pakistan, circulating throughout the year with a peak incidence in the post monsoon period. Median age of dengue patients has decreased and younger patients may be more susceptible. Total and differential leukocyte counts may help identify patients at risk of hemorrhage.     

Biosynthesized silver nanoparticles induce phytotoxicity in Vigna radiata L.

With the recent developments in the field of nanotechnology, the biosynthesis of nanoparticles has increased tremendously. Silver nanoparticles (SNPs) are among the most synthesized nanoparticles and this extensive synthesis can elevate the amounts of SNPs in the environment, which, consequently, pose a serious threat to the ecosystem and can bring unwanted environmental effects. As plants are an important part of ecosystem, investigation of toxic effects of SNPs on plants is particularly interesting. This study evaluates the potential risk of SNPs interaction with plants. For this, seeds of Vigna radiata L. were screened in presence of SNPs (20 mgL⁻¹) using the germination, growth, and biochemical parameters as a phototoxicity criterion. The 19.57 nm average-sized SNPs were synthesized via the biosynthesis method. These biosynthesized SNPs were then applied on two varieties of V. radiata (Azri and High cross 404) and found to have variety dependent toxic effects on seed germination, growth, and biochemical parameters. Seed germination, root length, shoot length, fresh weight, chlorophyll, carotenoid, sugar content, and total proteins were reduced by 20, 46, 50, 18, 55, 62, 82, and 67%, respectively, in High cross 404, when compared with control (distilled water). The variety Azri was less sensitive than the variety High cross 404. In conclusion, the results demonstrated that SNPs affect seed germination and seedling growth when internalized and accumulated in plants, revealing that SNPs were responsible for the side effects. More in-depth research is required, in the form of different concentrations of SNPs or different plant species, to draw a logical conclusion and develop legislation about the safe use of biosynthesized SNPs.Supplementary Information The online version contains supplementary material available at 10.1007/s12298-021-01073-4.     

Production of cyclodextrin glycosyltransferase by alkaliphilic <Emphasis Type="Italic">Bacillus circulans</Emphasis> in submerged and solid-state cultivation

Cyclodextrin glycosyltransferase (CGTase; E.C. 2.4.1.19) is an industrially important enzyme, which is used to produce cyclodextrins (CDs). In this research, we report the use of experimental factorial design to find the best conditions of pH and temperature for CGTase production by Bacillus circulans var. alkalophilus. The optimized calculated values for the tested variables were, respectively, pH 9.7 and temperature 36^oC, with a CGTase activity of 615 U mL⁻¹. The CGTase production was further studied with the optimized process parameters on submerged cultivations (SC) and solid-state cultivations (SSC) using soybean industrial fibrous residue (SIFR). The maximum CGTase activity obtained on SC was 1,155 U mL⁻¹ under aerobic conditions. Cell growth and CGTase synthesis in SSC using SIFR as substrate was excellent, with CGTase activity of 32,776 U g_(SIFR) ⁻¹. These results strongly support the use of SIFR for CGTase production since it is a non-expensive residue.     

Inhibition of rat testicular 17 alpha-hydroxylase and 17,20-lyase activities by anti-androgens (flutamide, hydroxyflutamide, RU23908, cyproterone acetate) in vitro

Flutamide, hydroxyflutamide, RU23908 and cyproterone acetate (CPA) inhibited rat testicular microsomal 17 alpha-hydroxylase and 17,20-lyase activities in vitro. The Km of [3H] progesterone for 17 alpha-hydroxylase was 45 +/- 0.62 nmol/l (+/- SEM, n = 12) and the Km of [3H] 17 alpha-hydroxyprogesterone for 17,20-lyase was 192 +/- 0.42 nmol/l (+/- SEM, n = 12). The Ki values for 17 alpha-hydroxylase, determined from Lineweaver-Burk plots were 102 +/- 3.2 mumol/l (+/- SEM, n = 6), 363 +/- 3.8 mumol/l (+/- SEM, n = 6), 118 +/- 1.4 mumol/l (+/- SEM, n = 6) and 123 +/- 2.1 mumol/l (+/- SEM, n = 6) for flutamide, hydroxyflutamide, RU23908 and CPA respectively. Flutamide and CPA were mixed-type inhibitors, whereas hydroxyflutamide and RU23908 were competitive inhibitors of 17 alpha-hydroxylase activity. Ki values for 17,20-lyase were 33 +/- 3.1 mumol/l (+/- SEM, n = 6), 112 +/- 3.1 mumol/l (+/- SEM, n = 6), 69 +/- 4.4 mumol/l (+/- SEM, n = 6) and 71 +/- 3.2 mumol/l (+/- SEM, n = 6) for flutamide, hydroxyflutamide, RU23908 and CPA, respectively. Inhibition was found to be competitive in each case. Although the characteristic action of anti-androgens is at the receptor level, these results demonstrate that anti-androgens may also have inhibitory effects on androgen biosynthesis which could prove to be of clinical significance.