Examination of Replication Dynamics in Fragile Sites Through Molecular Combing

Chromosomal fragile sites are specific loci that exhibit instability visible as gaps and breaks on the chromosome following inhibition of DNA synthesis and are generally categorized into two main classes: rare fragile sites (RFSs) and common fragile sites (CFSs). Under standard conditions, CFSs are typically stable but are prone to breakage in cells subjected to replication stress. In recent years, their role in the generation of gross chromosome rearrangements has become increasingly evident, and fragile sites have now connected to chromosome instability in cancer cells. The connection between CFSs and cancer thus highlights the importance of the regulation of DNA replication to prevent cancer development. The study of fragile sites in the yeast model organism has provided insight into the mechanisms that lead to breakage and genome instability. Through the process of molecular combing, replication dynamics can be observed at fragile sites to further understand the consequence of replication stress on DNA damage

Analysis of gene conversion tracts in \u3ci\u3eSaccharomyces cerevisiae\u3c/i\u3e

Common fragile sites are regions of the genome prone to gaps and breakage under replication stress. Repair of breaks at CFS can occur through homologous recombination. yet may lead to loss of heterozygosity (LOH) events that manifest themselves as gene conversions. Gene conversions associated with LOH have the potential to deactivate tumor suppressor genes, driving tumor progression. Using the yeast model, Saccharomyces cerevisiae, evidence of two types of gene conversions has emerged: short-tract and long-tract gene conversions. Gene conversion maps show a high frequency of short-tract gene conversions ending near or at the SUP4-o tRNA, in yeast strain Y657 that contains SUP4-o. We hypothesized that termination of these tracts is due to replication fork pause sites created by SUP4-o. We find the 2% difference in frequency of terminations between Y657, and our experimental yeast strain that contains SUP4-o, AMC355, does not provide statistical support for our hypothesis of SUP4-o causing termination of gene conversion tracts. We see that gene conversions near SUP4-o vary in their tract length. These gene conversions have implications for possible LOH after repair at fragile sites and may contribute to cancer progression

A Simple Assay to Screen Antimicrobial Compounds Potentiating the Activity of Current Antibiotics

Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract of Juglans regia tree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract of J. regia bark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria, Salmonella typhi or enteropathogenic E. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (\u3e30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action of J. regia extract against multiple drug-resistant bacteria when tested with a range of antibiotic

Genotype variation and genetic relationship among Escherichia coli from nursery pigs located in different pens in the same farm

BACKGROUND: So far, little is known about the genetic diversity and relatedness among Escherichia coli (E. coli) populations in the gut of swine. Information on this is required to improve modeling studies on antimicrobial resistance aiming to fight its occurrence and development. This work evaluated the genotype variation of E. coli isolated from swine fecal samples at the single pig and pen level, as well as between pens using repetitive extragenic palindromic (REP) PCR fingerprinting and pulsed field gel electrophoresis (PFGE). The genetic diversity of strains collected from media supplemented with ampicillin or tetracycline was also investigated. Besides, the genetic relationship of strains within each pen, between pens, as well as among strains within each group isolated from media with or without antibiotic, was assessed. RESULTS: REP-PCR patterns (N = 75) were generated for all the isolates (N = 720). Two profiles (REP_2 and REP_5) dominated, accounting for 23.7 and 23.3% of all isolates, respectively. At the pig and at the pen level, the number of different strains ranged from two to eight, and from 27 to 31, respectively, and multiple isolates from a single pen were found to be identical; however, in some of the pens, additional strains occurred at a lower frequency. E. coli isolates yielding different REP profiles were subjected to PFGE and led to 41 different genotypes which were also compared. CONCLUSIONS: Despite the presence of dominant strains, our results suggest a high genetic diversity of E. coli strains exist at the pen level and between pens. Selection with antibiotic seems to not affect the genetic diversity. The dominant REP profiles were the same found in a previous study in Denmark, which highlights that the same predominant strains are circulating in pigs of this country and might represent the archetypal E.coli commensal in pigs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12866-016-0912-3) contains supplementary material, which is available to authorized users

Genotype variation and genetic relationship among Escherichia coli from nursery pigs located in different pens in the same farm

Abstract Background So far, little is known about the genetic diversity and relatedness among Escherichia coli ( E. coli ) populations in the gut of swine. Information on this is required to improve modeling studies on antimicrobial resistance aiming to fight its occurrence and development. This work evaluated the genotype variation of E. coli isolated from swine fecal samples at the single pig and pen level, as well as between pens using repetitive extragenic palindromic (REP) PCR fingerprinting and pulsed field gel electrophoresis (PFGE). The genetic diversity of strains collected from media supplemented with ampicillin or tetracycline was also investigated. Besides, the genetic relationship of strains within each pen, between pens, as well as among strains within each group isolated from media with or without antibiotic, was assessed. Results REP-PCR patterns ( N \u2009=\u200975) were generated for all the isolates ( N \u2009=\u2009720). Two profiles (REP_2 and REP_5) dominated, accounting for 23.7 and 23.3% of all isolates, respectively. At the pig and at the pen level, the number of different strains ranged from two to eight, and from 27 to 31, respectively, and multiple isolates from a single pen were found to be identical; however, in some of the pens, additional strains occurred at a lower frequency. E. coli isolates yielding different REP profiles were subjected to PFGE and led to 41 different genotypes which were also compared. Conclusions Despite the presence of dominant strains, our results suggest a high genetic diversity of E. coli strains exist at the pen level and between pens. Selection with antibiotic seems to not affect the genetic diversity. The dominant REP profiles were the same found in a previous study in Denmark, which highlights that the same predominant strains are circulating in pigs of this country and might represent the archetypal E.coli commensal in pigs

Reaching the Unreachable: Barriers of the Poorest to Accessing NGO Healthcare Services in Bangladesh

The NGO Service Delivery Program (NSDP), a USAID-funded programme, is the largest NGO programme in Bangladesh. Its strategic flagship activity is the essential services package through which healthcare services are administered by NGOs in Bangladesh. The overall goal of the NSDP is to increase access to essential healthcare services by communities, especially the poor. Recognizing that the poorest in the community often have no access to essential healthcare services due to various barriers, a study was conducted to identify what the real barriers to access by the poor are. This included investigations to further understand the perceptions of the poor of real or imagined barriers to accessing healthcare; ways for healthcare centres to maximize services to the poor; how healthcare providers can maximize service-use; inter-personal communication between healthcare providers and those seeking healthcare among the poor; and ways to improve the capacity of service providers to reach the poorest segment of the community. The study, carried out in two phases, included 24 static and satellite clinics within the catchment areas of eight NGOs under the NSDP in Bangladesh, during June-September 2003. Participatory urban and rural appraisal techniques, focus-group discussions, and in-depth interviews were employed as research methods in the study. The target populations in the study included males and females, service-users and non-users, and special groups, such as fishermen, sex workers, potters, Bedes (river gypsies), and lower-caste people—all combined representing a heterogeneous community. The following four major categories of barriers emerged as roadblocks to accessing quality healthcare for the poor: (a) low income to be able to afford healthcare, (b) lack of awareness of the kind of healthcare services available, (c) deficiencies and inconsistencies in the quality of services, and (d) lack of close proximity to the healthcare facility. Those interviewed perceived their access problems to be: (a) a limited range of NGO services available as they felt what are available do not meet their demands; (b) a high service-charge for the healthcare services they sought; (c) higher prices of drugs at the facility compared to the market place; (d) a belief that the NGO clinics are primarily to serve the rich people, (e) lack of experienced doctors at the centres; and (f) the perception that the facility and its services were more oriented to women and children, but not to males. Others responded that they should be allowed to get treatment with credit and, if needed, payment should be waived for some due to their poverty level. While the results of the study revealed many perceptions of barriers to healthcare services by the poor, the feedback provided by the study indicates how important it is to learn from the poorest segment of society. This will assist healthcare providers and the healthcare system itself to become more sensitized to the needs and problems faced by this segment of the society and to make recommendations to remove barriers and improvement of access. Treatment with credit and waived payment for the poorest were also recommended as affordable alternative private healthcare services for the poor

Efficacy of Live attenuated and Inactivated Oil Emulsion Infectious Bursal Disease Virus Vaccines in Broiler chicks

This study was carried out with the aims to evaluate the efficacy of indigenous live and inactivated Infectious bursal disease virus (IBDV) vaccines in broilers. Two hundred and fifty (250), a-day-old broiler chicks divided into five groups (A-E) were immunized with live and inactivated vaccine at varying ages. Live vaccine was given to group A (at 8 days post hatch), B (at 8, 15 days post hatch), C (at 8, 15 and 23 days post hatch) and D (at 8 days post hatch). In addition group D received a booster dose of inactivated vaccine at 21 days of age, while group E served as control. Antibody titers were measured via Agar Gel Precipitation (AGP) test and ELISA, while the degree of protection against the virulent strains of IBDV was also recorded. Results showed that vaccine program adopted for group C and D produced significantly (P<0.05) higher antibody titer as compared to other groups. While a significant (P<0.05) difference in antibody titers was observed between group A and B while no considerable antibodies were detected in group E. The response to challenge dose was recorded as the difference of lesions in bursa, pectoral muscles or other visceral organs with the exception of group C and D. The study suggests that broiler chicks may be vaccinated at days 8, 15 and 23 with live attenuated vaccine or live attenuated vaccine followed by inactivated vaccine at days 8 and 21 that could provide an adequate protection against the virulent form of IBDV

Xylazine in the Opioid Epidemic: A Systematic Review of Case Reports and Clinical Implications

Introduction and objectives: The opioid overdose epidemic is exacerbated by the emergence of Xylazine as an illicit drug adulterant. Xylazine, a veterinary sedative, can potentiate opioid effects while also causing toxic and potentially fatal side effects. This systematic review aims to assess the impact of Xylazine use and overdoses within the opioid epidemic context.Method: A systematic search was conducted following PRISMA guidelines to identify relevant case reports, and case series related to Xylazine use. A comprehensive literature search included databases like Web of Science, PubMed, Embase, and Google Scholar, utilizing keywords and Medical Subject Headings (MeSH) terms related to Xylazine. Thirty-four articles met the inclusion criteria for this review. Results: Intravenous (IV) administration was a common route for Xylazine use among various methods, including subcutaneous (SC), intramuscular (IM), and inhalation, with overall doses ranging from 40 mg to 4300 mg. The average dose in fatal cases was 1,200 mg, compared to 525 mg in non-fatal cases. Concurrent administration of other drugs, primarily opioids, occurred in 28 cases (47.5%). Intoxication was identified as a notable concern in 32 out of 34 studies, and treatments varied, with the majority experiencing positive outcomes. Withdrawal symptoms were documented in one case study, but the low number of cases with withdrawal symptoms may be attributed to factors such as a limited number of cases or individual variation. Naloxone was administered in eight cases (13.6%), and all patients recovered, although it should not be misconstrued as an antidote for Xylazine intoxication. Of the 59 cases, 21 (35.6%) resulted in fatal outcomes, with 17 involving Xylazine use in conjunction with other drugs. The IV route was a common factor in six out of the 21 fatal cases (28.6%). Conclusion: This review highlights the clinical challenges associated with Xylazine use and its co-administration with other substances, particularly opioids. Intoxication was identified as a major concern, and treatments varied across the studies, including supportive care, naloxone, and other medications. Further research is needed to explore the epidemiology and clinical implications of Xylazine use. Understanding the motivations and circumstances leading to Xylazine use, as well as its effects on users, is essential for developing effective psychosocial support and treatment interventions to address this public health crisis