The end of the road for prostate specific antigen testing?

Many candidate biomarkers for diagnosis of prostate cancer have been investigated, but prostate‑specific antigen (PSA) testing remains the frontline test for both mass screening and individual clinical testing. Although the PSA test is cost‑effective, analytically reliable, and flexibly high throughput, it has a very weak correlation with prostate malignancy. This has resulted in over‑diagnosis and over‑treatment of patients leading to costly economic, social, and psychological impacts. PSA testing lacks the ability to molecularly characterize prostate diseases and define aggressiveness and lethality, which are necessary to influence choice of treatment. Therefore, newer molecular tests are beginning to replace the PSA tests. The prostate cancer antigen 3 test has shown superiority and is now widely used. The recently reported sarcosine urine test, the already delineated TMPRSS2: ETS fusion genes, the glutathione‑S‑transferase P1 serum marker, and enhancer of zeste homolog 2 biomarker may also help improve diagnosis and prognostication of prostate cancer. The analytical trend is toward a multiplex testing format using molecular and/or proteomic techniques that are reliable, accurate, reproducible, and ensure rapid quantitation. Therefore, validation of these newer biomarkers and their assays are necessary for both large‑scale clinical trials and clinical utility.Keywords: Prostate cancer and prostate cancer antigen 3, prostate cancer antigen 3, prostate specific antigen, sarcosineNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue

Allelic variants of KLK2 gene predict presence of prostate cancer at biopsy

Objective: Several single nucleotide polymorphisms associated with prostate cancer risk have been reported in recent years. We evaluated polymorphisms in the human glandular kallikrein 2 (KLK2) genes because the protein product of this gene is known to be increased in prostate cancer. Materials and methods: Blood samples were collected from sixty patients who underwent prostate biopsy sectioning, and from their genomic DNA the SNPs in KLK2 gene were investigated by direct DNA sequencing. Another 138 archived prostate tissue sections were also evaluated using the TaqMan SNP genotyping assay. Results: Eighteen known SNPs were identified in the KLK2 gene. The SNPs were located in introns, coding exons and untranslated regions of the gene. Further analysis showed that two of the SNPs were associated with prostate disease. The T/T allele of rs198977 was significantly predictive of the presence of prostate cancer at biopsy and was also associated with high tumour grade. The A/A allele of rs2664155 was also significantly associated with the presence of benign hyperplasia at biopsy. Conclusion: Our results support previous reports of association of the rs198977 SNP with prostate cancer risk and also indicated a link with the disease phenotype. However, the second SNP (rs2664155) was more associated with benign hyperplasia than prostate cancer risk. The method of TaqMan SNP genotyping could be clinically useful in genetic screening and risk stratification of patients for prostate diseases

Molecular detection and characterization of bacteria from CSF samples of patients with suspected cerebrospinal meningitis in parts of northern Nigeria using metagenomic DNA extracts

Background: The most commonly used approaches for detection and characterization of bacterial pathogens of meningitis in developing countries include culture, Gram stain, and latex agglutination. The positivity rate of culture is relatively low due to suboptimal storage and transportation conditions, culture practice, and/or antibiotic treatment administered before specimens are collected. Specimens that yield no growth in culture can still be analyzed using molecular methods, and metagenomic DNA (mDNA) extracted directly from clinical samples (CSF) can be used. We aimed to detect and characterize three major bacterial causes of cerebrospinal meningitis (CSM); Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae using mDNA extracted directly from CSF samples. Methodology: Metagenomic DNA templates were prepared directly from CSF specimens collected from 210 patients with suspected CSM. A multiplex Real Time PCR (mRT-PCR) using the ABI StepOne Plus Machine and Taqman Probe chemistry was used in the molecular detection, while serogroup/serotype-specific singleplex RT-PCR was used to characterize all positives samples. Results: Eighty-eight (41.9%) of the 210 samples were positive with the mRT-PCR assay for one or a combination of two of the three bacteria. Of these, 59 (67.1%) were N. meningitidis, 2 (2.3%) were H. influenzae, 3 (3.4%) were S. pneumoniae, 15 (17 %) had co-infections of N. meningitidis with H. influenzae, and 9 (10.2%) had co-infections of H. influenzae and S. pneumoniae. The serogroups of N. meningitidis encountered were A (13.5%), B (23%), C (8.1%), W135 (8.1%), X (5.4%), Y (32.4%), and non-groupable (9.5%). The serotypes of H. influenzae were Hia (3.8%), Hib (57.7%), Hic (3.85%), Hie (11.5%) and Hif (23.1%). The serotypes of S. pneumoniae were Wxy1 (8.3%), Wxy4 (33.3%), Wxy5 (50.0%), and Wxy9 (8.3%). Conclusion: Multiplex RT-PCR is a fast and accurate method for detecting and characterizing serogroups/serotypes of major bacteria implicated in CSM. Isolating DNA directly from CSF improves turnaround time, which will speed up patient care and management. Keywords: Cerebrospinal meningitis, metagenomic DNA, multiplex Real Time PCR, Northern Nigeria   French title: Détection moléculaire et caractérisation de bactéries à partir d'échantillons de LCR de patients suspectés de méningite cérébrospinale dans certaines parties du nord du Nigéria à l'aide d'extraits d'ADN métagénomique   Contexte: Les approches les plus couramment utilisées pour la détection et la caractérisation des agents pathogènes bactériens de la méningite dans les pays en développement comprennent la culture, la coloration de Gram et l'agglutination au latex. Le taux de positivité de la culture est relativement faible en raison des conditions de stockage et de transport sous-optimales, des pratiques de culture et/ou du traitement antibiotique administré avant le prélèvement des échantillons. Les échantillons qui ne donnent pas de croissance en culture peuvent toujours être analysés à l'aide de méthodes moléculaires, et l'ADN métagénomique (ADNm) extrait directement d'échantillons cliniques (LCR) peut être utilisé. Nous visions à détecter et à caractériser trois causes bactériennes majeures de la méningite cérébrospinale (CSM); Neisseria meningitidis, Haemophilus influenzae et Streptococcus pneumoniae à l'aide d'ADNm extrait directement d'échantillons de LCR. Méthodologie: Des matrices d'ADN métagénomique ont été préparées directement à partir d'échantillons de LCR prélevés sur 210 patients suspects de CSM. Une PCR multiplex en temps réel (mRT-PCR) utilisant la chimie de la machine ABI StepOne Plus et de la sonde Taqman a été utilisée pour la détection moléculaire, tandis que la RT-PCR monoplex spécifique au sérogroupe/sérotype a été utilisée pour caractériser tous les échantillons positifs. Résultats: Quatre-vingt-huit (41,9%) des 210 échantillons étaient positifs avec le test mRT-PCR pour une ou une combinaison de deux des trois bactéries. Parmi ceux-ci, 59 (67,1%) étaient N. meningitidis, 2 (2,3%) étaient H. influenzae, 3 (3,4%) étaient S. pneumoniae, 15 (17%) avaient des co-infections de N. meningitidis avec H. influenzae et 9 (10,2%) avaient des co-infections à H. influenzae et S. pneumoniae. Les sérogroupes de N. meningitidis rencontrés étaient A (13,5%), B (23%), C (8,1%), W135 (8,1%), X (5,4%), Y (32,4%) et non groupables (9,5%). Les sérotypes de H. influenzae étaient Hia (3,8%), Hib (57,7%), Hic (3,85%), Hie (11,5%) et Hif (23,1%). Les sérotypes de S. pneumoniae étaient Wxy1 (8,3%), Wxy4 (33,3%), Wxy5 (50,0%) et Wxy9 (8,3%). Conclusion: La RT-PCR multiplex est une méthode rapide et précise de détection et de caractérisation des sérogroupes/sérotypes des principales bactéries impliquées dans le CSM. Isoler l'ADN directement du LCR améliore le temps de traitement, ce qui accélérera les soins et la gestion des patients. Mots clés: méningite cérébro-spinale, ADN métagénomique, PCR multiplex en temps réel, nord du Nigéri

Enhancement of Bilirubin Excretion in Alloxan - Induced Diabetic Rats Treated with Crude Aloe vera Gel

This study was aimed at determining the effect of type 1 diabetes mellitus on bilirubin excretion, and to ascertain the impact of treatment with crude Aloe vera gel on bilirubin excretion. The phyto-constituents and median lethal dose of the plant material were determined before administration. Forty albino wistar rats were randomly assigned into four groups of 10 rats each as follows; control group, alloxan - induced diabetic untreated group (DM), alloxan - induced diabetic treated group (DMT) and control treated group (CT). The dose of crude Aloe vera gel used for this study was 0.2ml/100g body weight daily, per oral route. Biliary total bilirubin (BTB) and serum total bilirubin (STB) concentrations were significantly (p<0.001) increased in the DM group compared to control, DMT and CT group. BTB and STB concentrations were significantly lower (p<0.001) in DMT group compared to DM group. BTB and STB concentrations were significantly reduced in the CT group compared to control. Biliary conjugated bilirubin (BCB) and serum conjugated bilirubin (SCB) concentrations were significantly lower (p<0.001) in the DM, DMT and CT group compared to control. BCB and SCB concentrations were significantly lower (p<0.001) in the DMT group compared to DM group. BCB and SCB concentrations were significantly lower (p<0.001) in the CT group compared to control. Biliary unconjugated bilirubin (BUB) and serum unconjugated bilirubin (SUB) concentrations were significantly increased (p<0.001) in the DM group compared to control, DMT and CT group. BUB and SUB concentrations were significantly reduced (p<0.001) in CT group compared to control. These results are suggestive of the fact that crude Aloe vera gel enhances excretion of bilirubin in diabetic and normal conditions. Keywords Aloe vera, Bilirubin, Bile, Diabetes Mellitus, Seru

Quality of metagenomic DNA extracted for molecular identification of microorganisms from CSF samples of patients with suspected cerebrospinal meningitis in northern Nigeria

Background: Following an increase in the practice of starting antimicrobial therapy prior to clinical sample collection, the ability to confirm pathogenic microorganisms of bacterial meningitis has decreased by approximately 30%. Culture results may be false negative when fastidious or culture-resistant bacteria are involved or when patient samples are obtained after antimicrobial therapy has started. Molecular diagnosis using PCR can be performed directly on clinical samples after metagenomic DNA (mDNA) extraction not requiring live organisms for a positive result. The specific objectives of this study are to perform mDNA extraction directly from cerebrospinal fluids (CSF) using appropriate spin column method, and to determine the quality of the mDNA elute.Methodology: Cerebrospinal fluid specimens were collected from 210 patients with suspected acute cerebrospinal meningitis (CSM) in the Federal Capital Territory and some States in Northern Nigeria during the 2017 and 2018 outbreak seasons. Metagenomic DNA was extracted from approximately 200µL of CSF specimens using the Qiagen QIAamp(R) DNA Mini kit specific for bacterial agents only. DNA quality check was performed on all DNA elutes using fluorometric, spectrophotometric and agarose gel electrophoresis methods.Results: Of the 210 CSF samples analyzed microbiologically, Gram reaction was positive in 94 cases (44.8 %) but only 17 (8.1 %) were culture positive for two of the three major bacterial causes of meningitis. One hundred and eighty (85.7%) samples had DNA&nbsp; concentrations ≥ 0.005 ng/µL, 55 (30.6 %) of these had DNA purity (A260/A280) of ≥ 1.7, 103 (57.2%) had purity value between 1.0 - 1.69, 14 (7.8%) had value of 0.57 - 0.99, and 8 (4.4%) failed purity evaluation with value of 0.00 at A260/A280.Conclusion: The essence of mDNA extraction is multipurpose. A multiplex PCR can be performed on the extracted mDNA to interrogate the presence of microbial pathogens of interest using specific primers and probes (when applicable). Quality mDNA from CSF samples will ensure successful qPCR results for rapid and accurate detection of bacterial pathogens in meningitis. This will&nbsp; eliminate the challenges associated with traditional culture methods. Keywords: Meningitis, CSF, DNA Quality Check, Fluorometr

Titan: Earth-like on the outside, ocean world on the inside

Thanks to the Cassini-Huygens mission, Titan, the pale orange dot of Pioneer and Voyager encounters, has been revealed to be a dynamic, hydrologically shaped, organic-rich ocean world offering unparalleled opportunities to explore prebiotic chemistry. And while Cassini-Huygens revolutionized our understanding of each of the three "layers" of Titan-the atmosphere, the surface, and the interior-we are only beginning to hypothesize how these realms interact. In this paper, we summarize the current state of Titan knowledge and discuss how future exploration of Titan would address some of the next decade's most compelling planetary science questions. We also demonstrate why exploring Titan, both with and beyond the Dragonfly New Frontiers mission, is a necessary and complementary component of an Ocean Worlds Program that seeks to understand whether habitable environments exist elsewhere in our solar system

Higher incidence of premenopausal breast cancer in less developed countries; myth or truth?

Background: Fundamental etiologic differences have been suggested to cause earlier onset of breast cancer in less developed countries (LDCs) than in more developed countries (MDCs). We explored this hypothesis using world-wide breast cancer incidence data. Methods: We compared international age-standardized incidence rates (ASR) of pre- (<50 years) and postmenopausal (≥50 years) breast cancers as well as temporal trends in ASRs of pre-and postmenopausal breast cancer among selected countries during 1975–2008. We used joinpoint log-linear regression analysis to estimate annual percent changes (APC) for premenopausal and postmenopausal breast cancer in the northern Europe and in Black and White women population in the US. Results: Premenopausal breast cancers comprised a substantially higher proportion of all incident breast cancers in LDCs (average 47.3%) compared to MDCs (average 18.5%). However, the ASR of premenopausal breast cancer was consistently higher in MDCs (29.4/100,000) than LDCs (12.8/100,000). The ASR of postmenopausal cancer was about five-fold higher in the MDCs (307.6/100,000) than the LDCs (65.4/100,000). The APC of breast cancer in Denmark was substantially higher in postmenopausal (1.33%) than premenopausal cancer (0.98%). Higher incidence of breast cancer among the white than black women in the US was pertained only to the postmenopausal cancer. Conclusion: The substantial and consistent lower age-specific incidence of breast cancer in LDCs than in MDCs contradicts the theory of earlier onset. Demographic differences with fewer old women in LDCs and lower prevalence of risk factors of postmenopausal cancer are the most likely explanation to the lower mean age at diagnosis in these countries

Abiotic ammonium formation in the presence of Ni-Fe metals and alloys and its implications for the Hadean nitrogen cycle

Experiments with dinitrogen-, nitrite-, nitrate-containing solutions were conducted without headspace in Ti reactors (200°C), borosilicate septum bottles (70°C) and HDPE tubes (22°C) in the presence of Fe and Ni metal, awaruite (Ni80Fe20) and tetrataenite (Ni50Fe50). In general, metals used in this investigation were more reactive than alloys toward all investigated nitrogen species. Nitrite and nitrate were converted to ammonium more rapidly than dinitrogen, and the reduction process had a strong temperature dependence. We concluded from our experimental observations that Hadean submarine hydrothermal systems could have supplied significant quantities of ammonium for reactions that are generally associated with prebiotic synthesis, especially in localized environments. Several natural meteorites (octahedrites) were found to contain up to 22 ppm Ntot. While the oxidation state of N in the octahedrites was not determined, XPS analysis of metals and alloys used in the study shows that N is likely present as nitride (N3-). This observation may have implications toward the Hadean environment, since, terrestrial (e.g., oceanic) ammonium production may have been supplemented by reduced nitrogen delivered by metal-rich meteorites. This notion is based on the fact that nitrogen dissolves into metallic melts