Asymptomatic Persons Research Articles

TREX1 531C>T Polymorphism is Associated with High Proviral Load Levels in HTLV-1-Infected Persons.

Human T-lymphotropic virus type 1 (HTLV-1) deregulates the immune system and cell cycle, resulting in loss of immune tolerance and disease, including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Three prime repair exonuclease 1 (TREX1) maintains innate immune tolerance of the host and host-cell permissiveness to retroviral infections. TREX1 polymorphisms may influence the course of infection and autoimmune manifestations. The influence of TREX1 531C/T polymorphism was investigated in HTLV-1 infection and development of symptoms among 151 persons infected with HTLV-1 (32 HAM/TSP, 19 rheumatologic manifestations, two dermatitis, five more than one diagnosis, two probable HAM/TSP, and 91 asymptomatic individuals) and 100 uninfected persons in the control group. Polymorphism genotyping and proviral load quantification were performed by real-time polymerase chain reaction (PCR) and antinuclear antibodies (ANAs) were screened by an indirect immunofluorescence assay. No statistically significant difference was found in polymorphism genotype and allele frequencies between the infected and control groups. HAM/TSP patients showed higher frequency of TT genotype than asymptomatic persons (p = 0.0339). Proviral load was significantly higher among individuals with CT/TT genotypes and CC genotype carriers had lower proviral load and higher levels of proinflammatory cytokines. ANAs were present only in the HAM/TSP group. TREX1 531C>T polymorphism seems to be associated with TREX-1 regulation and HTLV-1 infection.

Abnormalities of DYRK1A-Cytoskeleton Complexes in the Blood Cells as Potential Biomarkers of Alzheimer's Disease.

Background:DYRK1A is implicated in mental retardation and Alzheimer’s disease (AD) dementia of Down syndrome (DS) individuals. The protein is associated with cytoskeleton and altered expression has been shown to impair the cytoskeletal network via dosage effect.Objective:Our original observations of marked reduction of cytoskeletal proteins associated with DYRK1A in brains and lymphoblastoid cell lines from DS and AD prompted an investigation whether cytoskeleton abnormalities could potentially be used as biomarkers of AD.Methods:Our assay relied on quantification of co-immunoprecipitated cytoskeletal proteins with DYRK1A (co-IP assay) and analysis of the profile of G- and F-actin fractions obtained by high-speed centrifugations (spin-down assay).Results:In co-IP assay, both DS and AD samples displayed reduced abundance of associated cytoskeletal proteins. In spin-down assay, G-actin fractions of controls displayed two closely spaced bands of actin in SDS-PAGE; while in AD and DS, only the upper band of the doublet was present. In both assays, alterations of actin cytoskeleton were present in DS, sporadic and familial AD cases, and in asymptomatic persons who later progressed to confirmed AD, but not in non-AD donors. In blind testing involving six AD and six controls, the above tests positively identified ten cases. Analysis of blood samples revealed the diversity of mild cognitive impairment (MCI) cases regarding the presence of the AD biomarker allowing distinction between likely prodromal AD and non-AD MCI cases.Conclusions:Both brain tissue and lymphocytes from DS and AD displayed similar semi-quantitative and qualitative alterations of actin cytoskeleton. Their specificity for AD-type dementia and the presence before clinical onset of the disease make them suitable biomarker candidates for early and definite diagnosis of AD. The presence of alterations in peripheral tissue points to systemic underlying mechanisms and suggests that early dysfunction of cytoskeleton may be a predisposing factor in the development of AD.

Prevalence and the Risk Factors for Asymptomatic Carotid Artery Stenosis Among Type II Diabetes Mellitus Patients

Prevalence and the Risk Factors for Asymptomatic Carotid Artery Stenosis Among Type II Diabetes Mellitus Patients

Targeting Immune Signaling Pathways in Clonal Hematopoiesis.

Myeloid neoplasms are a diverse group of malignant diseases with different entities and numerous patho-clinical features. They arise from mutated clones of hematopoietic stem- and progenitor cells which expand by outperforming their normal counterparts. The intracellular signaling profile of cancer cells is the sum of genetic, epigenetic and microenvironmental influences, and the multiple interconnections between different signaling pathways make pharmacological targeting complicated. To present an overview of known somatic mutations in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) and the inflammatory signaling pathways affected by them, as well as current efforts to therapeutically modulate this aberrant inflammatory signaling. In this review, we extensively reviewed and compiled salient information with ClinicalTrials.gov as our source on ongoing studies, and PubMed as our authentic bibliographic source, using a focused review question. Mutations affecting immune signal transduction are present to varying extents in clonal myeloid diseases. While MPN are dominated by a few common mutations, a multitude of different genes can be mutated in MDS and AML. Mutations can also occur in asymptomatic persons, a finding called clonal hematopoiesis of indeterminate potential (CHIP). Mutations in FLT3, JAK, STAT, CBL and RAS can lead to aberrant immune signaling. Protein kinase inhibitors are entering the clinic and are extensively investigated in clinical trials in MPN, MDS and AML. In summary, this article summarizes recent research on aberrant inflammatory signaling in clonal myeloid diseases and the clinical therapeutic potential of modulation of signal transduction and effector proteins in the affected pathways.

Early Detection of Diseases by Radiological Imaging: New Legal Situation and Evaluation of Service Offers using CT Examinations asan Example.

Radiological imaging offers promising prospects for the early detection of diseases. In Germany, the legal framework for such examinations was created by the Radiation Protection Law, which entered into force on December 31, 2018. Under this law, each specific type of radiodiagnostic screening of non-communicable diseases needs an approval on a generic level (permission) by a federal statutory ordinance, defining the specific requirements and conditions. It is the aim of the present paper, (i) to present in detail the new legal situation and (ii) to assess actual service offers for the screening of asymptomatic persons using CT examinations as an example. In February 2019, radiology institutions in Germany illegally offering on the Internet CT examinations for the screening of lung and colon cancer or coronary artery disease were identified. For each type of examination, 50 pertinent websites were evaluated particularly regarding the general information on the offered screening examination and the concrete procedure. In the vast majority of cases, the information provided on the websites was inadequate and disproportionately emphasized the benefits over the risks of the screening examination. Moreover, the offers differed substantially with respect to the age and risks factors of potential participants, the frequency of examinations, the screening procedure, and the diagnostic workup. The evaluated service offers strongly substantiate the need to define requirements and conditions regarding radiological screening examinations by statutory ordinances, in order to ensure an informed decision of potential screening participants as well as the benefit versus the risks of the procedures. · High-evidence studies prove the benefit of radiological screening for some diseases.. · In Germany, screening examinations are only permissible when stated in a federal statutory ordinance.. · At present, only mammography screening for breast cancer is permitted in Germany.. · CT screening examinations currently being conducted inGermany do not fulfill the legal and professional requirements.. · A review process has been initiated regarding possible generic approval of lung cancer screening.. · Brix G, Nekolla EA, Griebel J. Early Detection of Diseases by Radiological Imaging: New Legal Situation and Evaluation of Service Offers using CT Examinations as an Example. Fortschr Röntgenstr 2020; 192: 139 - 148.

Diagnostic Yield of One-Time Colonoscopy vs One-Time Flexible Sigmoidoscopy vs Multiple Rounds of Mailed Fecal Immunohistochemical Tests in Colorectal Cancer Screening

We compared the diagnostic yields of colonoscopy, flexible sigmoidoscopy, and fecal immunochemical tests (FITs) in colorectal cancer (CRC) screening. A total of 30,007 asymptomatic persons, 50-74 years old, were invited for CRC screening in the Netherlands. Participants were assigned to groups that received 4 rounds of FIT (mailed to 15,046 participants), once-only flexible sigmoidoscopy (n = 8407), or once-only colonoscopy (n = 6600). Patients with positive results from the FIT (≥10 μg Hb/g feces) were referred for colonoscopy. Patients who underwent flexible sigmoidoscopy were referred for colonoscopy if they had a polyp of ≥10 mm; adenoma with ≥25% villous histology or high-grade dysplasia; sessile serrated adenoma; ≥3 adenomas; ≥20 hyperplastic polyps; or invasive CRC. The primary outcome was number of advanced neoplasia detected (diagnostic yield) by each test. Secondary outcomes were number of colonoscopies needed to detect advanced neoplasia and number of interval CRCs found during each primary screening test. Patients with interval CRCs were found through linkage with Netherlands Cancer Registry. Advanced neoplasia were defined as CRC, adenomas ≥ 10 mm, adenomas with high-grade dysplasia, or adenomas with a villous component of at least 25%. The cumulative participation rate was significantly higher for FIT screening (73%) than for flexible sigmoidoscopy (31%; P < .001) or colonoscopy (24%; P < .001). The percentage of colonoscopies among invitees was higher for colonoscopy (24%) compared to FIT (13%; P < .001) or flexible sigmoidoscopy (3%; P < .001). In the intention to screen analysis, the cumulative diagnostic yield of advanced neoplasia was higher with FIT screening (4.5%; 95% CI 4.2-4.9) than with colonoscopy (2.2%; 95% CI, 1.8-2.6) or flexible sigmoidoscopy (2.3%; 95% CI, 2.0-2.7). In the as-screened analysis, the cumulative yield of advanced neoplasia was higher for endoscopic screening with colonoscopy (9.1%; 95% CI, 7.7-10.7) or flexible sigmoidoscopy (7.4%; 95% CI, 6.5-8.5) than with the FIT (6.1%; 95% CI, 5.7-6.6). All 3 screening strategies detected a similar proportion of patients with CRC. Follow-up times differed for each test (median 8.3 years for FIT and flexible sigmoidoscopy and 5.8 years for colonoscopy). Proportions of patients that developed interval CRC were 0.13% for persons with a negative result from FIT, 0.09% for persons with a negative result from flexible sigmoidoscopy, and 0.01% for persons with a negative result from colonoscopy. Mailed multiple-round FITs detect significantly more advanced neoplasia, on a population level, compared with once-only flexible sigmoidoscopy or colonoscopy screening. Significantly fewer colonoscopies are required by individuals screened by multiple FITs. Trialregister.nl numbers: first round, NTR1096; second round and additional invitees, NTR1512; fourth round, NTR5874; COCOS trial NTR1829.

Giardia lamblia assemblages A and B isolated from symptomatic and asymptomatic persons in Hamadan, west of Iran.

Giardia is a very abundant organism bringing about diarrhoea in human beings. The focus of this analysis was the detection of Giardia lamblia assemblages in human stool specimens in Hamadan, west of Iran, as well as the association between obtained assemblages and clinical symptoms. Faecal samples of 4066 individuals admitted tothe medical and health care facilities in Hamadan were inspected microscopically for the existence of Giardia cysts/trophozoites, and the clinical symptoms of the patients were recorded. The DNA of positive sampleswas isolated from and the nucleotide sequences of both glutamate dehydrogenase (gdh) (n = 15) and triose phosphate isomerase (tpi) (n = 8) genes were analyzed. In direct microscopy, a total of sixty-four samples (1.6%), were considered as positive for G. lamblia cysts or trophozoites. The sequence analysis showed that 18 out of 23 sequenced isolates (78.2%) were assemblage A and 5 (21.7%) were assemblage B. Clinical symptoms were observed in 44.4% and 40% of patients with assemblages A and B, respectively. Overall, the predominant assemblage A detected in the tested samples along with bioinformatics analysis suggest a potential zoonotic transmission in the region of the study. Although advanced analyses are necessary to understand the foundation and path of the infection, it seems that more sanitary regulations regarding contact with livestock and pet animals are essential.

Asymptomatic malaria infections and Pfmdr1 mutations in an endemic area of Nigeria

BackgroundMalaria eradication globally is yet to be achieved and transmission is sustained in many endemic countries. Plasmodium falciparum continues to develop resistance to currently available anti-malarial drugs, posing great problems for malaria elimination. This study evaluates the frequencies of asymptomatic infection and multidrug resistance-1 (mdr-1) gene mutations in parasite isolates, which form the basis for understanding persistently high incidence in South West, Nigeria.MethodsA total of 535 individuals aged from 6 months were screened during the epidemiological survey evaluating asymptomatic transmission. Parasite prevalence was determined by histidine-rich protein II rapid detection kit (RDT) in healthy individuals. Plasmodium falciparum mdr-1 gene mutations were detected by polymerase chain reaction (PCR) followed by restriction enzyme digest and electrophoresis to determine polymorphism in parasite isolates. Sequencing was done to confirm polymorphism. Proportions were compared using Chi-square test at p value < 0.05.ResultsMalaria parasites were detected by RDT in 204 (38.1%) individuals. Asymptomatic infection was detected in 117 (57.3%) and symptomatic malaria confirmed in 87 individuals (42.6%). Overall, individuals with detectable malaria by RDT was significantly higher in individuals with symptoms, 87 of 197 (44.2%), than asymptomatic persons; 117 of 338 (34.6%), p = 0.02. In a sub-set of 75 isolates, 18(24%) and 14 (18.6%) individuals had Pfmdr1 86Y and 1246Y mutations.ConclusionsThere is still high malaria transmission rate in Nigeria with higher incidence of asymptomatic infections. These parasites harbour mutations on Pfmdr1 which contribute to artemisinin partner drug resistance; surveillance strategies to reduce the spread of drug resistance in endemic areas are needed to eliminate the reservoir of malaria parasites that can mitigate the eradication of malaria in Nigeria.

Overdiagnosis in respiratory medicine.

Overdiagnosis in respiratory medicine.

PB2266 HOW TO IMPROVE HEMATOLOGIC REFERRAL? ANALYSIS AND RECOMMENDATIONS

Background:Incidental laboratorial abnormalities detected in asymptomatic persons are increasingly becoming a frequent motive for referral to a haematological consultation, overloading outpatient units that are run by small teams. These referrals, along with the subsequent acceptance by the triage manager and further haematological investigation by a haematologist, originate from the fear of missing incipient severe haemopathies.Aims:To evaluate the adequacy and the result of these referrals to ascertain the hypothesis that a large proportion of the cases have no indication for specialized haematological care.Methods:Retrospective analysis of patients referred to the Haematology consult of a central hospital over a 2‐year period (Jan/16‐Dec/17), excluding the ones who already had a known diagnosis. We evaluated the reason for referral, the final diagnosis and at a second stage we tried to quantify the referrals which could be managed in primary care, and their origin.Results:Out of 1162 evaluable patients (236 still in study), the majority (65%) came from Primary Health Care. The motive, in 85% of the cases, consisted in blood count abnormalities (59% cytopenias). In 13% of the cases, the initial abnormality no longer existed upon arrival. Finding an underlying pathology was possible in only 48% of the cases. From these, 14% could have been managed in Primary Health Care (e.g. iron deficiency; vitamin deficits) and 86% were haematologically relevant. As for the referrals which could have been avoided (no underlying haematological pathology or unconfirmed motive) the most frequent causes were cytopenias (anaemia 33%, leukopenia 15%, thrombocytopenia 12%) and they originated from Primary Health Care (72%).Summary/Conclusion:In this sample, we confirmed that a high proportion of referrals are manageable in Primary Health Care, particularly cytopenias, part of which are no longer present at the first haematological evaluation. The probability of a haematological investigation resulting in a clinically relevant diagnosis is very low, seemingly not justifying the consult time, the costs for the system or the personal costs for the patient. The elaboration of specifically designed recommendations for Primary Health Care and the implementation of interaction/discussion networks of pre‐triage cases are indispensable measures to optimize the haematological referral process.

Laryngeal and Vocal Characterization of Asymptomatic Adults With Sulcus Vocalis.

Introduction Sulcus vocalis is defined as a longitudinal depression on the vocal cord, parallel to its free border. Its most marked characteristic is breathlessness, caused by incomplete glottal closure, in addition to roughness, due to the decrease in mucosal wave amplitude of the vocal cords. Vocal acoustic aspects, such as fundamental voice frequency, jitter, and shimmer, may also be altered in individuals with this type of laryngeal disorder. To assess the voice of individuals with sulcus vocalis, studies generally include a sample of subjects with vocal symptoms, excluding asymptomatic persons. To better characterize the vocal characteristics of individuals with sulcus vocalis, their asymptomatic counterparts must also be included. Objective Characterize the larynx and voice of asymptomatic adults with sulcus vocalis. Method A total of 26 adults, 13 with sulcus vocalis (experimental group) and 13 without (control group) were assessed. All the participants were submitted to suspension microlaryngoscopy, voice self-assessment, auditory perception and acoustic evaluation of the voice. Results Among the individuals with sulcus vocalis, 78% of the sulci were type I and 22% type II. Auditory perception assessment obtained statistically significant lower scores in individuals with sulcus vocalis compared with the control group, and a slight difference in the overall degree of hoarseness and roughness. No statistically significant intergroup diferences were found in self-reported voice or acoustic assessment. Conclusion Type I was the predominant sulcus vocalis observed in individuals without voice complaints, who may also exhibit slight changes in vocal quality and roughness.

Out of Center Sleep Testing in Ostensibly Healthy Middle Aged to Older Adults.

Out of Center Sleep Testing (OCST) is used increasingly to diagnose obstructive sleep apnea (OSA). However, there are few data using OCST that quantify the amount of intrinsic apneic and hypopneic events among asymptomatic healthy persons, especially those who are elderly. This analysis reports the results of OCST in a small group of ostensibly healthy asymptomatic individuals. The study population was comprised of ostensibly healthy middle-aged to elderly volunteers for studies of circadian physiology. Before undergoing an OCST, they were found to be free of any chronic medical or psychiatry condition by history, physical and psychologic examination and by a variety of questionnaires and laboratory tests. There were 24 subjects ranging in age from 55-70 years who had an OCST performed. Repeat studies were required in only 3 subjects. Over half the study population was over the age of 60 years (54.2% vs 45.8%); the majority were men (70.8%). The mean apnea hypopnea index (AHI) was 9.2 /hour with no difference between younger and older subjects. However, 11 had an AHI ≥ 5 /hour. Five had an AHI ≥15 /hour and 2 had an AHI ≥40 /hour. Those with an AHI <15 /hour had a mean AHI of 4.4 /hour (95% CI:2.8-6.0 /hour). Although OCST has a low failure rate, there is a high prevalence of intrinsic obstructive apnea and hypopnea in ostensibly healthy asymptomatic persons.

Does low back pain affect the reliability of postural regulation?

The aim of this study was to examine the intraobserver reliability of a posturographic assessment in patients with low back pain. We investigated 24 symptomatic subjects with defined low back pain (mean: 57.9 years) and a pair-matched control group including 24 asymptomatic persons (mean: 58.1 years). Each participant underwent two measurements on a posturographic device (32 Hz sampling rate) based on the Interactive Balance System (time interval: 7 d). Test procedure consisted of tests on solid ground with eyes open (1) and eyes closed (2). Data analysis included parameters of motor output and a frequency band analysis. Reliability tests were realized using by intraclass correlations (ICC). Coefficients of ICC ranged from 0.36 (95% CI: 0.01–0.73) to 0.94 (95% CI: 0.86–0.97) in both test positions. For 69% (11/16) of the investigated parameters a high level (ICC > 0.75) of intraobserver reliability was reached. Based on the results, the posturographic measurement system used in this study seems to be appropriate for use in longitudinal study designs in an orthopaedic setting.

WHEN DOES A CALCIUM SCORE EQUATE TO SECONDARY PREVENTION: INSIGHTS FROM THE CONFIRM REGISTRY

Asymptomatic persons with elevated CAC scores have been shown to have increased cardiovascular risk. We measured event rates of those with established ASVCD and compared to a cohort of asymptomatic persons (stratified by CAC) to determine what CAC level approximates secondary risk. Using the CONFIRM

Prevalence of infection among asymptomatic and paucisymptomatic contact persons exposed to Ebola virus in Guinea: a retrospective, cross-sectional observational study

The prevalence of Ebola virus infection among people who have been in contact with patients with Ebola virus disease remains unclear, but is essential to understand the dynamics of transmission. This study aimed to identify risk factors for seropositivity and to estimate the prevalence of Ebola virus infection in unvaccinated contact persons. In this retrospective, cross-sectional observational study, we recruited individuals between May 12, 2016, and Sept 8, 2017, who had been in physical contact with a patient with Ebola virus disease, from four medical centres in Guinea (Conakry, Macenta, N'zérékoré, and Forécariah). Contact persons had to be 7 years or older and not diagnosed with Ebola virus disease. Participants were selected through the Postebogui survivors' cohort. We collected self-reported information on exposure and occurrence of symptoms after exposure using a questionnaire, and tested antibody response against glycoprotein, nucleoprotein, and 40-kDa viral protein of Zaire Ebola virus by taking a blood sample. The prevalence of Ebola virus infection was estimated with a latent class model. 1721 contact persons were interviewed and given blood tests, 331 of whom reported a history of vaccination so were excluded, resulting in a study population of 1390. Symptoms were reported by 216 (16%) contact persons. The median age of participants was 26 years (range 7-88) and 682 (49%) were male. Seropositivity was identified in 18 (8·33%, 95% CI 5·01-12·80) of 216 paucisymptomatic contact persons and 39 (3·32%, 5·01-12·80) of 1174 (2-4) asymptomatic individuals (p=0·0021). Seropositivity increased with participation in burial rituals (adjusted odds ratio [aOR] 2·30, 95% CI 1·21-4·17; p=0·0079) and exposure to blood or vomit (aOR 2·15, 1·23-3·91; p=0·0090). Frequency of Ebola virus infection varied from 3·06% (95% CI 1·84-5·05) in asymptomatic contact persons who did not participate in burial rituals to 5·98% (2·81-8·18) in those who did, and from 7·17% (3·94-9·09) in paucisymptomatic contact persons who did not participate in burial rituals to 17·16% (12·42-22·31) among those who did. This study provides a new assessment of the prevalence of Ebola virus infection among contact persons according to exposure, provides evidence for the occurrence of paucisymptomatic cases, and reinforces the importance of closely monitoring at-risk contact persons. Institut National de la Santé et de la Recherche Médicale, Reacting, the French Ebola Task Force, Institut de Recherche pour le Développement, and Montpellier University Of Excellence-University of Montpellier.

Recognizing the Potential for Overdiagnosis: Are High-Sensitivity Cardiac Troponin Assays an Example?

Overdiagnosis is commonly conceptualized as an unintended consequence of early disease detection in asymptomatic persons but can also occur in persons with symptoms. This commentary poses ways to i...

Surface ultrastructure, protein profile and zymography of Blastocystis species isolated from patients with colorectal carcinoma.

Oncogenic potential of Blastocystis species have been predicted on reporting the enhanced proliferation of human colorectal cancer cells by the parasite solubilized antigen in vitro, and the enhanced drug-induced carcinogenesis by infection in vivo. The present study is the first to investigate some phenotypic characters, namely the surface ultrastructure, protein profiles and protease activity of Blastocystis sp. isolated from three different clinical groups: colorectal carcinoma (CRC) patients, symptomatic and asymptomatic infected persons. Under SEM, all CRC Blastocystis sp. isolates had a very rough intensely folded surface in comparison to the less rough and completely smooth surface of all symptomatic and asymptomatic Blastocystis sp. Non-CRC isolates, respectively. Under reducing conditions, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis had shown a significant presence of 2 protein bands of 230 and 32KDa in 42.9% of Blastocystis sp. CRC isolates with their complete absence from Non-CRC isolates. While using non-reducing condition with the incorporation of gelatin in the gel to study the protease activity of the parasite, no significant difference existed between isolates of the three groups. In conclusion, the significant difference in surface ultrastructure and in protein profiles exists between Blastocystis sp. of CRC and Non-CRC isolates. These differences might be either secondary to the altered gut environment in the presence of CRC or are indicators of a different pathogenic potential of the parasite isolates inducing malignancy.

The role of IgG avidity determination in diagnosis of West Nile virus infection

Purpose: West Nile virus (WNV) IgM antibodies have been shown to persist for up to 500 days or even longer in some patients. Therefore, additional tests are needed to confirm primary infection. The aim of this study was to analyze the value of IgG avidity in diagnosis of symptomatic and asymptomatic WNV infection. Methods & Materials: A total 54 WNV IgM and/or IgG positive serum samples collected from 39 patients with neuroinvasive disease (meningitis/encephalitis/myelitis) and 15 asymptomatic persons were tested for WNV IgG avidity. Serological tests were performed using a commercial enzyme-linked immunosorbent assay (Euroimmun, Lübeck, Germany) and confirmed by virus neutralization test. Avidity index (AI) was calculated and expressed as percentage using the extinction values with and without urea treatment. The interpretation of AI results was determined as follows: AI < 40% = low avidity antibodies indicating acute primary infection; AI 40-60% = borderline avidity indicating recent (post-acute) infection; AI > 60% = high avidity antibodies indicating past WNV infection. Results: WNV IgM antibodies were detected in 47/87.0% samples: 39/100% patients with neuroinvasive disease and 8/53.3% asymptomatic subjects. Recent WNV infection was documented by low/borderline AI in 44/93.6% IgM positive samples. In 3/6.4% IgM positive samples, high AI was detected indicating persisting IgM antibodies from a previous infection. All 7 IgM negative samples showed high AI. In 33/84.6% patients with WNV neuroinvasive disease tested within 30 days after onset of symptoms AI was low. Six patients (15.4%) tested 34-50 days after disease onset showed borderline AI (42-60%) indicating earlier maturation of WNV IgG antibodies. Conclusion: The results of this study indicate that IgG avidity differentiates current/recent WNV infection from persistent IgM antibodies both in patients with WNV neuroinvasive disease and asymptomatic persons. Since many patients showed rapid avidity maturation, a low IgG avidity is indicative of WNV infection within the previous month.

Cancer Screening Markers: A Simple Strategy to Substantially Reduce the Sample Size for Validation.

Studies to validate a cancer prediction model based on cancer screening markers collected in stored specimens from asymptomatic persons typically require large specimen collection sample sizes. A standard sample size calculation targets a true-positive rate (TPR) of 0.8 with a 2.5% lower bound of 0.7 at a false-positive rate (FPR) of 0.01 with a 5% upper bound of 0.03. If the probability of developing cancer during the study is P = 0.01, the specimen collection sample size based on the standard calculation is 7600. The strategy to reduce the specimen collection sample size is to decrease both the lower bound of TPR and the upper bound of FPR while keeping a positive lower bound on the anticipated clinical utility. The new sample size calculation targets a TPR of 0.4 with a 2.5% lower bound of 0.10 and an FPR of 0.0 with a 5% upper bound of 0.005. With P = 0.01, the specimen collection sample size based on the new calculation is 1800 instead of 7600. The new sample size calculation requires a minimum benefit/cost ratio (number of false positives traded for a true positive). With P = 0.01, the minimum cost-benefit ratio is 5, which is plausible in many studies. In validation studies for cancer screening markers, the strategy can substantially reduce the specimen collection sample size, substantially reducing costs and making some otherwise infeasible studies now feasible.

Colonoscopic Review and Surgical Approach in the Management of Colorectal Carcinoma–A Retrospective Study of 50 cases

Introduction: There is no exact statistics about the incidence of colorectal cancer in Bangladesh. According to National Cancer Institute, London, it is the 2nd most common cancer affecting more than 30,000 people in each year. As many patients with colon cancer do not develop symptoms until it is advanced and detection in early stage can only be achieved by screening of asymptomatic person. Maximum patients present lately with distance metastases when there is nothing to treat except palliative therapy. Objectives: To identify the risk factors, early symptoms, signs, treatment modalities, operative outcome, morbidity and mortality rate.&#x0D; Materials and Methods: This retrospective study was carried out at CMH Dhaka during August 2002 to August 2004. A total of 50 patients were taken as study sample. All the patients were admitted in different surgical units of CMH Dhaka for surgical treatment. Detailed history were taken on admission by a questionnaire and examined thoroughly and findings regarding Anaemia, Jaundice, Dehydration, Oedema, Lymphadenopathy, Nutritional status and abnormal signs like ascites, distension, rigidity, organomegaly recorded. Digital rectal examination were done in all cases and finally examined by Proctoscope, Sigmoidoscope and with Colonoscope. FOBT (Fecal Occult Blood Test), serum tumour marker was also assessed.&#x0D; Results: Out of 50 cases 22 were rectal carcinoma and next common site was caecum and number was 10. There was a variation in the sex ratio. Out of 50 cases 33 were male and 17 were female. The highest incidence was among people of 6th decade (28%) and next highest was in 4th decade (24%). Majority of patient with right colon cancer presented with abdominal pain 12 out of 22 cases (56%) and weight loss 15 cases (68%). For left colon cancer commonest symptom was weight loss and weakness and altered bowel habit. Almost all cases with rectal carcinoma presented with bleeding per rectum.&#x0D; Conclusion: About 50% of lesions were found in recto-sigmoid junction and male: female ratio was 1.9:1. All efforts and modern technology should be applied for early detection and treatment. The survival rate is usually very poor in rectal carcinoma. In this study most of the cases were subjected to post operative Chemo and Radiotherapy, but more were treated with neoadjuvant chemoradiation for down staging. The need for early detection of Colorectal Carcinoma (CRC) should be stressed in the form of screening patient awareness and understanding about symptomatology. Early diagnosis and definitive treatment are thereby increasing expectation of higher survival and better prognosis in patient of colorectal carcinoma.&#x0D; Journal of Armed Forces Medical College Bangladesh Vol.11(2) 2015: 36-40