Comparison of Histological, Microbiological, and Molecular Methods in Diagnosis of Patients with TBLN Having Different Anti-TB Treatment Background

Objective The influence of anti-tuberculosis （TB） treatment history on tuberculous lymphadenitis （TBLN） diagnosis is unclear. Therefore, this study aims to evaluate the diagnostic methods, including histology, microbiology, and molecular tests, used for TBLN. Methods In this study, suspected patients with TBLN and having different anti-T8 treatment background were enrolled. All the samples were tested simultaneously by histology, ZiehI-Neelsen （ZN） staining, mycobacterial culture （culture）, Xpert MTB/RIF （xpert）, real-time PCR, and high-resolution melting curve PCR （HRM）. Thereafter, the performance of these methods on samples with different anti-TB treatment background was assessed. Results In our study, 89 patients were prospectively included 82 patients with TBLN and 7 with other diseases. The overall sensitivities of Xpert, real-time PCR, histology, ZN staining, and culture were 86.6%, 69.5%, 58.5%, 43.9%, and 22.0%, respectively. The anti-TB treatment history revealed dramatic influences on the sensitivity of culture （P 〈 0.0001）. In fact, the treatment that lasted over 3 months also influenced the sensitivity of Xpert （P 〈 0.05）. However, the treatment history did not affect the performance of remaining tests （P 〉 0.05）. For rifampicin drug susceptibility test （DST）, the anti-T8 treatment showed only significant influence on the success rate of culture DST （P = 0.001）, but not on those of Xpert and HRM tests （P 〉 0.05）. Conclusion Other tests as welt as culture should be considered for patients with TBLN having retreatment history or over 1-month treatment to avoid false negative results.

Noninvasive molecular analysis of Helicobacter pylori : Is it time for tailored first-line therapy?

The main problem of Helicobacter pylori(H. pylori) infection management is linked to antibiotic resistances. This phenomenon has grown in the last decade, inducing a dramatic decline in conventional regimen effectiveness. The causes of resistance are point mutations in bacterial DNA, which interfere with antibiotic mechanism of action, especially clarithromycin and levofloxacin. Therefore, international guidelines have recently discouraged their use in areas with a relevant resistance percentage, suggesting first-line schedules with expected high eradication rates, i.e., bismuth containing or non-bismuth quadruple therapies. These regimens require the daily assumption of a large number of tablets. Consequently, a complete adherence is expected only in subjects who may be motivated by the presence of major disorders. However, an incomplete adherence to antibiotic therapies may lead to resistance onset, since sub-inhibitory concentrations could stimulate the selection of resistant mutants. Of note, a recent meta-analysis suggests that susceptibility tests may be more useful for the choice of first than second-line or rescue treatment. Additionally, susceptibility guided therapy has been demonstrated to be highly effective and superior to empiric treatments by both meta-analyses and recent clinical studies. Conventional susceptibility test is represented by culture and antibiogram. However, the method is not available everywhere mainly for methodology-related factors and fails to detect hetero-resistances. Polymerase chain reaction(PCR)-based, culture-free techniques on gastric biopsy samples are accurate in finding even minimal traces of genotypic resistant strains and hetero-resistant status by the identification of specific point mutations. The need for an invasive endoscopic procedure has been the most important limit to their spread. A further step has, moreover, been the detection of point mutations in bacterial DNA fecal samples. Few studies on clarithromycin susceptibility have shown an overall high sensitivity and specificity when compared with culture or PCR on gastric biopsies. On these bases, two commercial tests are now available although they have shown some controversial findings. A novel PCR method showed a full concordance between tissue and stool results in a preliminary experience. In conclusion, despite poor validation, there is increasing evidence of a potential availability of noninvasive investigations able to detect H. pylori resistances to antibiotics. These kinds of analysis are currently at a very early phase of development and caution should be paid about their clinical application. Only further studies aimed to evaluate their sensitivity and specificity will afford novel data for solid considerations. Nevertheless, noninvasive molecular tests may improve patient compliance, time/cost of infection management and therapeutic outcome. Moreover, the potential risk of a future increase of resistance to quadruple regimens as a consequence of their use on large scale and incomplete patient adherence could be avoided.

A Brief Overview of Research on Chemical Molecular Contamination in Cleanrooms

This review proposes associated standards from abroad regarding chemical contamination of the air, and has analyzed the formation of chemical air pollution, the common contaminants and the testing methods of projects. This paper demonstrates the capability of China to begin commercial testing of chemical contamination of the air. In addition, it offers technological references of the feasibility for adopting the international standard ISO14644-8：2006.

Laboratory Diagnosis of Acute Leukemia in Kenya: The Gaps and Opportunities

Acute leukemia (AL) is a malignant disease of the bone marrow in which hematopoietic precursors are arrested in an early stage of development. The diagnosis of leukemia and lymphomas, beyond morphology, is limited in low-resource countries including Kenya. Morphological diagnosis includes Cytological and Histological assessment of blood, bone marrow aspirates and tissues on suspected Acute leukemia patients. The World Health Organization (WHO, 2016) international guidelines on Acute leukemia diagnosis recommend that cytogenetic analysis, appropriate molecular genetics, Fluorescent in situ Hybridization (FISH) testing, and flow cytometric immuno-phenotyping should be done in addition to a morphologic assessment of Acute Leukemia. In facilities where resources are relatively available, immunophenotypic and genetic features have resulted not only in providing a more accurate leukemia diagnosis but also in identifying antigens or genes that can then be targeted for therapy. This article will look at the gaps in the diagnosis of Acute leukemia in low-resource settings like Kenya and opportunities available to improve diagnosis.

Optimization and Testing for PCR System of Rice by Orthogonal Design

[Objective] This study was to screen the economic or stable PCR system of rice and detect the generality of the selected system in different molecular markers based on PCR.[Method] With DNA extracted from rice leaves by CTAB method as the template,PCR system was optimized by L16(45)orthogonal design.[Result] Clear bands were amplified from 16 different combinations,but the amplification effects and yields had difference.The most economic and applicable system was as follows:20 ng DNA template,150 μmol/L dNT...

Genetic Transformation of Aloe barbadensis Miller by Agrobacterium tumefaciens

Despite the importance of aloe in cosmetic and pharmaceutical industries, improvement of aloe （Aloe barbadensis Miller） by genetic engineering was seldom reported previously. In this study, regeneration and transformation conditions, including explant selection and surface sterilization, use of different Agrobacterium strains, and co-culture processing, are optimized. The use of 20.0% sodium hypochloride （25 rain） for sterilization was less detrimental to the health of explant than 0.1% mercuric chloride （10 min）. Regeneration frequency from stems was much higher than that from leaves or sheaths. Explants were infected by Agrobacterium （30 rain） in liquid co-cultural medium, and this was followed by three days co-culture on sterile filter papers with light for 10 h per day at 24℃. Histochemical data demonstrated that the transient expression of GUS gene in the stem explants of aloe infected with Agrobacterium strains EHAI05 and C58CI was 80.0% and 30.0%, respectively, suggesting the higher sensitivity of the explants to EHAI05 than to C58C1. Infected tissues were selected using G418 （10.0-25.0 mg/L） to generate transformants. Sixty-seven G418 resistant plantlets were generated from the infected explants. Southern blotting, PCR, and ELISA analyses indicated that the alien gene were successfully transferred into aloe and was expressed in the transgenic plants. This newly established transformation system could be used for the genetic improvement of aloe.

Human bocavirus: Current knowledge and future challenges

Human bocavirus(HBoV) is a parvovirus isolated about a decade ago and found worldwide in both respiratory samples, mainly from early life and children of 6-24 mo of age with acute respiratory infection, and in stool samples, from patients with gastroenteritis. Since then, other viruses related to the first HBoV isolate(HBoV 1), namely HBoV 2, HBoV 3 and HBoV 4, have been detected principally in human faeces. HBo Vs are small nonenveloped single-stranded DNA viruses of about 5300 nucleotides, consisting of three open reading frames encoding the first two the non-structural protein 1(NS1) and nuclear phosphoprotein(NP1) and the third the viral capsid proteins 1 and 2(VP1 and VP2). HBoV pathogenicity remains to be fully clarified mainly due to the lack of animal models for the difficulties in replicating the virus in in vitro cell cultures, and the fact that HBo V infection is frequently accompanied by at least another viral and/or bacterial respiratory and/or gastroenteric pathogen infection. Current diagnostic methods to support HBoV detection include polymerase chain reaction, real-time PCR, enzymelinked immunosorbent assay and enzyme immunoassay using recombinant VP2 or virus-like particle capsid proteins, although sequence-independent amplification techniques combined with next-generation sequencing platforms promise rapid and simultaneous detection of the pathogens in the future. This review presents the current knowledge on HBoV genotypes with emphasis on taxonomy, phylogenetic relationship and genomic analysis, biology, epidemiology, pathogenesis and diagnostic methods. The emerging discussion on HBoV s as true pathogen or innocent bystander is also emphasized.

Antimicrobial susceptibility testing for Helicobacter pylori in times of increasing antibiotic resistance

The gram-negative bacterium Helicobacter pylori(H.pylori)causes chronic gastritis,gastric and duodenal ulcers,gastric cancer and mucosa-associated lymphoid tissue lymphoma.Treatment is recommended in all symptomatic patients.The current treatment options for H.pylori infection are outlined in this review in light of the recent challenges in eradication success,largely due to the rapid emergence of antibiotic resistant strains of H.pylori.Antibiotic resistance is a constantly evolving process and numerous studies have shown that the prevalence of H.pylori antibiotic resistance varies significantly from country to country,and even between regions within the same country.In addition,recent data has shown that previous antibiotic use is associated with harbouring antibiotic resistant H.pylori.Local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy.Antimicrobial resistance is assessed by H.pylori culture and antimicrobial susceptibility testing.Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H.pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material.Accumulating evidence indicates that surveillance of antimicrobial resistance by susceptibility testing is feasible and necessary to inform clinicians in their choice of therapy for management of H.pylori infection.

Endoscopic ultrasound guided fine needle aspiration and useful ancillary methods

The role of endoscopic ultrasound(EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within the mediastinum and abdominal cavity allow detection of small focal lesions and precise tissue acquisition from suspected lesions within the reach of this method. Fine needle aspiration(FNA) is considered of additional value to EUS and is performed to obtain tissue diagnosis. Tissue acquisition from suspected lesions for cytological or histological analysis allows, not only the differentiation between malignant and non-malignant lesions, but, in most cases, also the accurate distinction between the various types of malignant lesions. It is well documented that the best results are achieved only if an adequate sample is obtained for further analysis, if the material is processed in an appropriate way, and if adequate ancillary methods are performed. This is a multi-step process and could be quite a challenge in some cases. In this article, we discuss the technical aspects of tissue acquisition by EUS-guided-FNA(EUS-FNA), as well as the role of an on-site cytopathologist, various means of specimen processing, and the selection of the appropriate ancillary method for providing an accurate tissue diagnosis and maximizing the yield of this method. The main goal of this review is to alert endosonographers, not only to the different possibilities of tissue acquisition, namely EUS-FNA, but also to bring to their attention the importance of proper sample processing in the evaluation of various lesions in the gastrointestinal tract and other accessible organs. All aspects of tissue acquisition(needles, suction, use of stylet, complications, etc.) have been well discussed lately. Adequate tissue samples enable comprehensive diagnoses, which answer the main clinical questions, thus enabling targeted therapy.

A Comprehensive Overview of the Paradigm of Laboratory Findings in the Diagnosis of the Pandemic Coronavirus Disease 2019 (COVID-19) in India

COVID-19 is a pandemic disease caused by 2019 Novel Coronavirus or SARS-CoV-2. As this disease is highly contagious and rapidly spreading, so all countries have to increase their level of preparedness, alert, and response to identify, manage, and care for new cases of COVID-19;laboratory testing is an integral part of this strategy. Accurate results by laboratory diagnosis are beneficial for public health.

Access to quality diagnosis and rational treatment for tuberculosis: real-world evidenee from China-Gates Tuberculosis Control Project Phase Ⅲ

Background:China has successfully reduced tuberculosis(TB)incidence rate over the past three decades,however,challenges remain in improving the quality ofTB diagnosis and treatment.I n this paper,we assess the effects of the implementation of"China National Health Commission(NHC)and Gates Foundation TB Preventi on and Control Pro-jectwon the quality ofTB care in the three provinces.