Rapid Diagnostic Results Research Articles

Ensemble learning prediction framework for EGFR amplification status of glioma based on terahertz spectral features

Epidermal growth factor receptor (EGFR) plays a pivotal role in the initiation and progression of gliomas. In particular, in glioblastoma, EGFR amplification emerges as a catalyst for invasion, proliferation, and resistance to radiotherapy and chemotherapy. Current approaches are not capable of providing rapid diagnostic results of molecular pathology. In this study, we propose a terahertz spectroscopic approach for predicting the EGFR amplification status of gliomas for the first time. A machine learning model was constructed using the terahertz response of the measured glioma tissues, including the absorption coefficient, refractive index, and dielectric loss tangent. The novelty of our model is the integration of three classical base classifiers, i.e., support vector machine, random forest, and extreme gradient boosting. The ensemble learning method combines the advantages of various base classifiers, this model has more generalization ability. The effectiveness of the proposed method was validated by applying an individual test set. The optimal performance of the integrated algorithm was verified with an area under the curve (AUC) maximum of 85.8 %. This signifies a significant stride toward more effective and rapid diagnostic tools for guiding postoperative therapy in gliomas.

Developing inclusive digital health diagnostic for schistosomiasis: a need for guidance via target product profiles

IntroductionThe INSPIRED project aims to develop inclusive Digital Optical Diagnostic Devices (DODDs) for schistosomiasis, to support disease management by enabling rapid diagnostic results, to improve efficient data management to guide decision-making and to provide healthcare workers with critical health information to facilitate follow-up action. Due to the non-availability of Target Product Profiles (TPPs) for guiding the development of digital diagnostics for schistosomiasis, we explored existing diagnostic TPPs.MethodsUsing a curated open access database (Notion database), we studied a selection of TPPs for diagnosing infectious diseases, focusing on specifications related to digital health products for Neglected Tropical Diseases (NTDs).ResultsEighteen TPPs originating from 12 documents, covering 13 specific diseases, were selected and their characteristics were labeled and entered into the database. Further exploration of the database revealed several gaps, including a lack of stakeholder input, sustainability, and TPP availability. Other significant gaps related to digital health platform interconnectivity and data stewardship specifically in relation to digital diagnostics, including DODDs.DiscussionThese findings reflect two possible scenarios: (1) there is currently no need for digital diagnostic devices for schistosomiasis and, by extension for other NTDs; or (2) those needs are not yet covered by TPPs. Therefore, we recommend that digital health diagnostics are included in the use cases for schistosomiasis control and elimination, at least in the ideal/desirable scenario, as this will guide research and incentivize investment in digital health diagnostics for schistosomiasis.

An Artificial Intelligence Algorithm to Optimize the Classification of the Hepatitis Type

Hepatitis is one of the diseases that has become more developed in recent years in terms of the high number of infections. Hepatitis causes inflammation that destroys liver cells, and it occurs as a result of viruses, bacteria, blood transfusions, and others. There are five types of hepatitis viruses, which are (A, B, C, D, E) according to their severity. The disease varies by type. Accurate and early diagnosis is the best way to prevent disease, as it allows infected people to take preventive steps so that they do not transmit the difference to other people, and diagnosis using artificial intelligence gives an accurate and rapid diagnostic result. Where the analytical method of the data relied on the radial basis network to diagnose the disease, in addition to using the classification of the regression tree as well as the use of the genetic algorithm to improve the classification accuracy of both methods and by comparing the methods used to find out the most efficient methods of classification through criteria. Classification error, mean square root error, and average absolute relative error, and concluded that the experimental results are that the methods are good in terms of classification, as they gave results with less classification of error, and that the radial basis network was superior to the classification regression tree, and that the addition of the genetic algorithm led to an improvement classification accuracy.
 Paper type: Research paper.

876. Suggested Empiric Therapy for CoNS Identified by BioFire BCID2 – Making Mountains Out of Molehills?

Abstract Background Coagulase-negative Staphylococci (CoNS), including mecA-positive Staphylococcus epidermidis (MRSE), are among the bacteria identified by BioFire blood culture identification (BCID2). After transition to BCID2 on 31 March 2021, our institution began providing a suggested empiric antimicrobial therapy (EAT) comment with rapid diagnostic results, whereas no suggestions were given with the prior platform. Limited data exist on the impact of EAT suggestions on antibiotic use when likely contaminants such as CoNS are identified. Methods This was a single center, observational, pre- and post-intervention study of patients aged ≥ 18 years with CoNS in the blood between 1 April 2020 and 30 September 2021. Patients with compromised immunity, intravenous drug use, polymicrobial cultures, or MRSE-active therapy use for a documented infection were excluded. Primary outcome was the rate of initiation or discontinuation of MRSE-active agent in response to the rapid diagnostic result. Secondary outcome was healthcare resource utilization such as Infectious Diseases consultation and delayed discharge. Results A total of 174 patients were included (pre-BCID2, n=93; post-BCID2, n=81). For all CoNS rapid diagnostic results, no significant difference was noted in MRSE-active agent initiation (33.3% vs. 37.0%, p=.90) and discontinuation (61.3% vs. 48.4%, p=.31). A subgroup analysis of S. epidermidis was performed with 64 and 46 patients in pre- and post-BCID2 groups, respectively; in the latter, BCID2 identified 31/46 (67.4%) as MRSE. In this subgroup, empiric MRSE-active agent was significantly less likely to be discontinued if EAT suggestion was reported with results (68.4% vs. 31.2%, p=.03). This change was not seen if Staphylococcus species were identified as the suggestion was to withhold EAT. There was no difference in healthcare resource utilization. Conclusion Providing EAT suggestion with BCID2 result for S. epidermidis unexpectedly encouraged continuing empiric MRSE-active agent for likely contaminants. In contrast, suggestion to withhold treatment had no impact on EAT use for other CoNS. The reason for this difference is unclear, but may be a result of the highlighted methicillin resistance in the BCID2 result reporting which is specific to S. epidermidis. Disclosures James S. Lewis, PharmD, FIDSA, Cidara: Advisor/Consultant|Merck: Advisor/Consultant|SeLux Diagnostics: Advisor/Consultant.

195. Reducing Time to Optimal Antimicrobial Therapy (OAT) for Bloodstream Infections (BSI) due to Gram Positive Cocci (GPC) in Chains Using Rapid Diagnostics Paired with Antimicrobial Stewardship (ASP) Efforts

Abstract Background Rapid microbiology diagnostic results paired with immediate ASP intervention have been shown to decrease time to OAT and improve patient outcomes. For Gram positive (GP) BSI, studies have primarily focused on Staphylococci. However, the value of using rapid diagnostics for GPC in chains is not well studied. With the use of BioFire® FilmArray® Blood Culture Identification 2 (BCID2) to identify GPC in chains, we aimed to compare the time to OAT between pre- and post- implementation. Methods In May 2021, our institution implemented the use of BCID2 for GPC in chains, which detects 5 types of GPC in chains to the species level and the van A/B gene. Positive results were communicated in real time 24/7 to ASP who provided recommendations on OAT to the treatment team. A retrospective chart review compared the pre-implementation cohort (Jan - Sept 2019) to the post-implementation cohort (May 2021 - Jan 2022). The following patients were excluded from analysis: < 18 years of age, presence of polymicrobial infection or Streptococci with unidentified species by BCID2, discharged or deceased before rapid diagnostic result, on comfort measures or left against medical advice within 72 hours of result. The primary study endpoint was time to OAT which was defined as time from positive Gram stain to OAT. Secondary outcomes included percentage of ASP recommendations accepted, length of stay (LOS), and 30-day mortality. Results A total of 199 patients met inclusion criteria, 117 pre-cohort vs. 82 post-cohort. Baseline demographics were similar in both groups with the exception of the post-cohort having a numerically higher Charlson Comorbidity Index (Table 1). The most common sources of the bacteremias were intra-abdominal, skin and soft tissue, and endovascular (Table 2). The primary endpoint, average time to OAT, was 35 hours in the pre-cohort and 18 hours in the post-cohort with a difference of 16.8 hours (95% CI 9.8 – 23.8; p < 0.0001) (Table 3). ASP recommendations were accepted 91% of the time. The median LOS was 9 days (IQR 6 - 21) in the pre-cohort vs. 13 days (IQR 7-32) in the post-cohort (p = 0.07). The 30-day mortality rate was numerically lower in the pre-cohort (6.1% vs. 10.3%; p = 0.79). Conclusion For BSI due to GPC in chains, rapid diagnostics via BCID2 paired with 24/7 ASP led to markedly decreased time to OAT. Disclosures David Peaper, MD, Tangen Biosciences: Stocks/Bonds.

Dual-miRNA-Propelled Three-Dimensional DNA Walker for Highly Specific and Rapid Discrimination of Breast Cancer Cell Subtypes in Clinical Tissue Samples

Dual-miRNA-Propelled Three-Dimensional DNA Walker for Highly Specific and Rapid Discrimination of Breast Cancer Cell Subtypes in Clinical Tissue Samples

Which pharmacists are performing antimicrobial stewardship: A national survey and a call for collaborative efforts.

To determine how pharmacists with formal antimicrobial stewardship program (ASP) responsibilities prioritize their time and pharmacists without formal antimicrobial stewardship program responsibilities contribute to ASP activities. A nationwide survey. Members of the American College of Clinical Pharmacy who subscribe to the following practice and research network e-mail listservs: infectious diseases, adult medicine, cardiology, critical care, hematology-oncology, immunology and transplantation, and pediatrics. A survey was distributed via listservs. Respondents were asked about their personal and institutional demographics and ASP activities. In total, 245 pharmacists responded: 135 pharmacists with formal antimicrobial stewardship program responsibilities; 110 pharmacists without formal antimicrobial stewardship program responsibilities. Although most respondents had completed a general pharmacy residency (85%), only 20% had completed an infectious diseases (ID) specialty residency. Among pharmacists with formal antimicrobial stewardship program responsibilities, one-third had no formal training or certification in ID or ASP. Pharmacists without formal antimicrobial stewardship program responsibilities spent ∼12.5% of their time per week on ASP activities, whereas pharmacists with formal antimicrobial stewardship program responsibilities spent 28% of their time performing non-ASP activities. Pharmacists with formal antimicrobial stewardship program responsibilities were more likely than pharmacists without formal antimicrobial stewardship program responsibilities to perform antibiotic guideline development (P < .001), antibiotic-related education (P = .002), and direct notification of rapid diagnostic results (P = .018). Pharmacists with formal antimicrobial stewardship program responsibilities without formal ID training or certification spent less time on ASP activities and were more likely to perform lower-level interventions. Many ASP activities are being performed by pharmacists without formal ID training. To ensure the future success of ASPs, pharmacists with formal antimicrobial stewardship program responsibilities should have adequate training to meet more advanced metrics, and more pharmacists without formal antimicrobial stewardship program responsibilities should be included in basic interventions.

Performance of Verigene Rapid Diagnostic Testing for Detection of Inpatient Pediatric Bacteremia.

Verigene blood culture panels comprise rapid diagnostic testing, which aids in early bacteremia species identification. This study determined the concordance of Verigene rapid diagnostic results compared with the Vitek reference standard in patients admitted to a children's hospital. This was a 3-year retrospective observational study of neonatal and pediatric patients ≤18 years admitted to a children's hospital with confirmed bacteremia for whom Verigene testing was performed. Verigene testing was conducted on cultures with reported growth on Gram stain and final organism speciation confirmed via Vitek. Percent concordance and positive percent agreement with 95% CIs were calculated for Verigene panel-identifiable organisms. Negative percent agreement with 95% CIs was calculated for non-panel organisms. Time-to-result was calculated from Gram stain reporting to both Verigene and Vitek final organism susceptibility. One hundred thirty-five Gram-positive (GP) and 51 Gram-negative (GN) isolates were identified through Vitek. Verigene GP panel-detectable organisms were correctly identified 96.9% (125/129) at the genus level and 95.3% (123/129) at the species level. Overall positive percent agreement was 95.3 (CI: 90.2-98.3). Negative percent agreement was 83.3 (CI: 35.9-99.6) for the 6 non-panel GP organisms. All GN isolates were correctly identified on Verigene. Median time-to-result was 2.9 hours (IQR 2.6, 3.2) and 44.4 hours (IQR: 35.4, 52.5) for Verigene and final susceptibilities, respectively. There was a statistically significant time savings of 41.5 hours (CI: 29.8-53.2) for identification and detection of resistance markers (p < 0.0001). Verigene concordance at our institution aligns with results from previously published studies and can be considered a reliable clinical decision-support tool.

Mini review: genome and transcriptome editing using CRISPR-cas systems for haematological malignancy gene therapy.

The recent introduction of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR associated protein (Cas) systems, offer an array of genome and transcriptome editing tools for clinical repair strategies. These include Cas9, Cas12a, dCas9 and more recently Cas13 effectors. RNA targeting CRISPR-Cas13 complexes show unique characteristics with the capability to engineer transcriptomes and modify gene expression, providing a potential clinical cancer therapy tool across various tissue types. Cas13 effectors such as RNA base editing for A to I replacement allows for precise transcript modification. Further applications of Cas13a highlights its capability of producing rapid diagnostic results in a mobile platform. This review will focus on the adaptions of existing CRISPR-Cas systems, along with new Cas effectors for transcriptome or RNA modifications used in disease modelling and gene therapy for haematological malignancy. We also address the current diagnostic and therapeutic potential of CRISPR-Cas systems for personalised haematological malignancy.

1331. Interpretation and Application of Rapid Diagnostic Methodologies: The Positive Impact of Online, Curriculum-Based Learning

BackgroundAntibiotic resistance has become one of the most serious public health threats today. Used appropriately, newer rapid diagnostic methodologies have the potential to positively impact care by informing a more targeted treatment approach that can reduce inappropriate antibiotic use, support antimicrobial stewardship, shorten hospital stays, and improve clinical outcomes.MethodsTo improve ID specialists’ knowledge and application of rapid diagnostic tests, a CME/ABIM MOC/ACCENT certified curriculum was developed. The curriculum comprised a series of 4 educational episodes, each with a video commentary from a clinical expert and each focused on a different site of infection: (a) Episode 1: CNS; (b) Episode 2: Gastrointestinal tract; (c) Episode 3: Respiratory tract; and (d) Episode 4: Bloodstream. The episodes in the curriculum were launched in serial fashion between October 30, 2018 and February 11, 2019, on a website dedicated to continuous professional development. Educational effectiveness was assessed with a repeated-pairs pre-/post-assessment study design; each individual served as his/her own control. A chi-square test assessed changes pre- to post-assessment. P values of < 0.05 are statistically significant. Effect sizes were evaluated using Cramer’s V (<0.05 modest; 0.06–0.15 noticeable effect; 0.16–0.26 considerable effect; >0.26 extensive effect).Results15,092 HCPs, including 10,894 physicians have participated in the curriculum. This initial analysis comprises data from the subset of ID specialists from each episode who answered all pre-/post-assessment questions through March 18, 2019; data collection is ongoing. Following participation, significant improvements were observed overall (P ≤ 0.002 for each episode) and on the specific topics assessed in each episode (Graph). Additionally, 51%–55% of ID specialists indicated an intent to modify their diagnostic approach and 15%–29% had increased confidence in applying the rapid diagnostic results into patient care.ConclusionThis educational curriculum significantly improved ID specialists’ knowledge of the strengths and limitations of different rapid diagnostic methodologies and improved the applications of test findings into clinical decision-making. These findings highlight the positive impact of well-designed online education. Disclosures All authors: No reported disclosures.

Generation of monoclonal antibodies against foot-and-mouth disease virus SAT 2 and the development of a lateral flow strip test for virus detection.

Foot-and-mouth disease (FMD) remains a major economic concern for the livestock productivity in many developing countries and a continued threat to countries that are disease free because of its potential devastating impact on agricultural, food chain and tourism sectors. FMD virus (FMDV) is recognized as having seven serotypes: O, A, C, Asia 1, South African Territories (SAT) 1, 2, 3 and multiple subtypes within each serotype. FMD outbreaks due to SAT 2 have been reported in many African countries. The development of a rapid and easily performed test for FMD detection is critical for controlling FMD outbreaks and containing its spread. The present project developed a lateral flow immunochromatographic (LFI) strip test for the rapid detection of FMDV SAT 2. A panel of monoclonal antibodies (mAbs) against FMDV serotype SAT 2 was produced and characterized. One mAb (#10) was selected as the capture mAb because it reacted to all 23 SAT 2 isolates archived at the National Center for Foreign Animal Disease. The LFI strip test was developed using biotin-conjugated mAb #10, and the colloid gold-conjugated FMDV serotype-independent mAb as the detection mAb. A generic Rapid Assay Device (gRAD) with one test line and a control line was used for the test. The LFI strip test detected all 23 tested SAT 2 isolates and recent outbreak strains. The results indicated that the diagnostic specificity and sensitivity of the LFI strip test were greater than the double antibody sandwich (DAS) DAS ELISA. The ability of the LFI strip test to produce rapid diagnostic results will be useful for early on-site diagnosis during FMD outbreaks.

1797. Combining Rapid Diagnostics With Pharmacy Resident-Led Antimicrobial Stewardship to Optimize Outcomes for Bacteremia With Methicillin-Resistant S. aureus (MRSA-B), Methicillin-Susceptible S. aureus (MSSA-B), and Coagulase-Negative Staphylococcus (CoNS) at Yale New Haven Hospital (YNHH)

BackgroundGiven the severity of S. aureus bacteremia, prompt initiation of appropriate antibiotics is key. YNHH implemented the Cepheid® Xpert MRSA/SA PCR in an effort to decrease the time needed to identify MRSA-B, MSSA-B, and CoNS. The impact of rapid diagnostics has been limited without stewardship or infectious disease involvement. Our unique notification algorithm utilized our on-call pharmacy residents to allow for 24/7 coverage. The primary objective was time to optimal antibiotic therapy (OAT) before and after implementation of the PCR and algorithm. Secondary outcomes included time to blood culture clearance (BCC), acceptance rate of pharmacist interventions, days of vancomycin therapy avoided, and 30-day mortality.MethodsA retrospective cohort study was conducted in adult inpatients with blood cultures positive for Gram positive cocci in clusters. The pre-implementation, control group (CG) included patients from April 2017 to October 2017 and the post-implementation, intervention group (IG) was from October 2017 to April 2018. Patients <18 years and polymicrobial bacteremia were excluded. Data collected in addition to primary and secondary outcomes included baseline demographics, allergies and empiric antibiotics. OAT included vancomycin for MRSA-B or MSSA-B with severe β-lactam allergy; nafcillin or cefazolin for MSSA-B; and discontinuation of vancomycin for CoNS deemed a contaminant.ResultsOf the 544 patients reviewed, 434 met inclusion criteria: 182 in the CG and 252 in the IG with similar baseline characteristics. Mean time to OAT decreased from 10 hours in the CG to 5 hours in the IG (P = 0.006). Time to BCC in the CG and IG cohorts decreased from 100 to 43 hours (P = 0.0001). One day of vancomycin was avoided in patients with MSSA-B and 2 days with CoNS. 30-day mortality decreased from 18% (n = 32) in the CG vs. 6% (n = 15) in the IG (P = 0.0001). Finally, 95% (n = 153/161) of pharmacist interventions were accepted.ConclusionUtilizing the on-call pharmacy resident for notification of rapid diagnostic results for S. aureus bacteremia, we saw a significant decrease in time to OAT, BCC, and 30-day mortality. Our study demonstrates that in the setting of limited stewardship resources, additional members of the healthcare team can be used to optimize antibiotics in conjunction with rapid diagnostics.Disclosures All authors: No reported disclosures.

Evaluation of the GeneXpert MTB/RIF assay on extrapulmonary and respiratory samples other than sputum: a low burden country experience

The aim of this study was to assess the performance of the GeneXpert MTB/RIF assay on extrapulmonary (EP) and respiratory (non-sputum) clinical samples of patients suspected of having tuberculosis (TB) from Queensland, Australia. A total of 269 EP and respiratory (non-sputum) clinical samples collected from Qld patients who were suspected of having TB were subjected to the GeneXpert MTB/RIF analysis, Ziehl-Neelsen (ZN) staining, Mycobacterium tuberculosis (MTB) culture and drug susceptibility testing. Phenotypic and genotypic data were compared. The overall performance analysis of the GeneXpert MTB/RIF assay for detection of MTB complex demonstrated sensitivity of 89%, specificity of 95%, PPV of 89% and NPV of 95% using culture as a reference standard. The GeneXpert MTB/RIF analysis of acid-fast bacilli (AFB) smear positive samples and AFB smear negative samples showed sensitivities of 100% and 77%, respectively. Looking at individual EP and respiratory (non-sputum) sample types, the sensitivity ranged from 60% to 100% although the specificity ranged from 33% to 100% with the specificity of lymph node tissue biopsy being the lowest. The GeneXpert MTB/RIF assay detected 11% more TB cases than culture and 27% more cases than ZN microscopy. Due to insufficient numbers of presenting rifampicin resistance cases, performance analysis of the GeneXpert MTB/RIF assay on rifampicin resistance could not be carried out. The GeneXpert MTB/RIF assay is potentially valuable for TB diagnosis in the majority of the EP and respiratory (other than sputum) samples in our setting. Although the GeneXpert MTB/RIF assay provides rapid diagnostic results, the overall sensitivity to rule out the disease is suboptimal for some specimen types. Performance varied according to specimen type and AFB smear status. The sensitivity and specificity of lymph node tissue was 63% and 33%. Care must be taken when using the GeneXpert MTB/RIF assay for detection of MTB in lymph node tissue samples. All samples should be cultured regardless of the GeneXpert MTB/RIF assay result.

A wavelike buffer for introducing samples into autonomous capillary microfluidic devices

The microfluidic technique has gained attention due to its advantages in providing a rapid diagnostic result for on-site diagnosis and treatment. To obtain a quantitative and reproducible diagnostic result the fluid flow in the microfluidic device must be steady. However, a non-specific flow will always form due to the disturbances introduced during the sample injecting process. Here, a wavelike sample introduction buffer is presented. The buffer can change the longitudinal flow of the injected sample to a transverse flow, which will consume the kinetic energy and eliminate disturbances. By using the buffer, fluid flow within a microfluidic device can become steady. The effects of the buffer parameters on buffering performance have been studied. Results show that the buffering performance increases as the waved peak height and peak number decrease. This buffer has a simple structure. It requires no external power supplies or complicated fabrication process. It will be helpful in improving the diagnostic accuracy of microfluidic devices.

Mikrofluidische Automatisierung in der Molekulardiagnostik

Easy-to-use point-of-care (POC) tests provide rapid diagnostic results near the patient, enabling fast decision-making in patient management. However, the implementation of automated molecular diagnostic POC tests still faces technical challenges. We demonstrate a highly sensitive POC platform for automated molecular diagnostics of neonatal sepsis that uses a mobile analyzer and unit-use test carriers.

A research protocol for developing a Point-Of-Care Key Evidence Tool ‘POCKET’: a checklist for multidimensional evidence reporting on point-of-care in vitro diagnostics

IntroductionPoint-of-care in vitro diagnostics (POC-IVD) are increasingly becoming widespread as an acceptable means of providing rapid diagnostic results to facilitate decision-making in many clinical pathways. Evidence in utility, usability and...

Attenuated Total Reflection Fourier Transform Infrared (ATR‐FTIR) spectral discrimination of brain tumour severity from serum samples

Gliomas are the most frequent primary brain tumours in adults with over 9,000 people diagnosed each year in the UK. A rapid, reagent-free and cost-effective diagnostic regime using serum spectroscopy would allow for rapid diagnostic results and for swift treatment planning and monitoring within the clinical environment. We report the use of ATR-FTIR spectral data combined with a RBF-SVM for the diagnosis of gliomas (high-grade and low-grade) from non-cancer with sensitivities and specificities on average of 93.75 and 96.53% respectively. The proposed diagnostic regime has the ability to reduce mortality and morbidity rates.

Method of specimen fixation and pathological dissection of colorectal cancer influences retrieval of lymph nodes and tumour nodal stage

Introduction There is now evidence that meticulous specimen dissection may «upstage» around one-quarter of colorectal cancers from node negative to node positive, although there is much debate as to how to achieve this: some authors prefer fat clearance techniques while others have opted for more conventional lymph-node retrieval with manual specimen «breadknifing» and lymph-node palpation. While fat clearance is probably the optimum technique, it is time-consuming, costly and does not provide rapid diagnostic results. Methods A prospective pathological study of 50 colorectal cancer resections was conducted with 100 comparison cases, the study group receiving at least an additional 24-h fixation of the mesocolonic or mesorectal fat in 10% aqueous formaldehyde prior to specimen dissection.Results The percentage of node-negative colorectal cancer was significantly lower in the study group compared with the matched comparison group: (18) 36% compared with (55) 55% of comparison cases. Conclusions Effective lymph-node retrieval techniques require mesocolic/mesorectal fat to be adequately fixed prior to pathological dissection. This study suggests that satisfactory lymph-node retrieval is possible without fat clearance, provided the mesenteric fat is suitably fixed prior to colorectal cancer specimen dissection.

Suitability of infection of cells in suspension for detection of herpes simplex virus

Detection of herpes simplex virus in clinical specimens by the suspension-infection technique was compared with detection by conventional cell culture. The sensitivity and specificity of the suspension-infection technique compared with those of conventional culture were 95.9 to 98.2% and 97.5 to 100%, respectively, depending on the cell line used in the tests. The mean time to diagnosis by the suspension-infection technique was 1 day, compared with 4.8 days by conventional culture. Comparable detection of low-level positive specimens was observed with the methods. In a clinical setting, the isolation rates obtained by suspension-infection and conventional culture were indistinguishable. These results indicate that the suspension-infection method can be used for the detection of herpes simplex virus and can yield rapid diagnostic results without a time-consuming centrifugation step.