Use of Automated Urine Microscopy Analysis in Clinical Diagnosis of Urinary Tract Infection: Defining an Optimal Diagnostic Score in an Academic Medical Center Population.

A retrospective case record study was conducted that established a scoring tool based on clinical and iQ200 parameters, able to predict or rule out the clinical diagnosis of UTI in the majority of adult patients in an academic hospital. Automated standardized quantitative urine analysis, such as iQ200 analysis, is on the rise because of its high accuracy and efficiency compared to those of traditional urine analysis. Previous research on automated urinalysis focused mainly on predicting culture results but not on the clinical diagnosis of urinary tract infection (UTI). A retrospective analysis was conducted of consecutive urine samples sent in for culture because of suspected UTI. UTI was defined by expert opinion, based on reported symptoms, conventional urine sediment analysis, and urine cultures. Parameters of iQ200 analysis and clinical symptoms and signs were compared between cases and controls. Optimal cutoff values were determined for iQ200 parameters, and multivariate logistic regression analysis was used to identify the set of variables that best predicts the clinical diagnosis of UTI for development of a scoring tool. A total of 382 patients were included. Optimal cutoff values of iQ200 analysis were 74 white blood cells (WBC)/µl, 6,250 "all small particles" (ASP)/µl, and a bacterial score of 2 on an ordinal scale of 0 to 5. The scoring tool attributed 1 point for frequent micturition or increased urge, 2 points for dysuria, 1 point for a bacterial score of ≥2, 2 points for WBC/µl of ≥50, and an additional point for WBC/µl of ≥150. This score had a sensitivity of 86% and a specificity of 92% when using a threshold of <4 points. The combination of iQ200 analysis and a simple survey could predict or rule out UTIs in a majority of patients in an academic medical center.

Interlaboratory Collaboration for Optimized Screening for Urinary Tract Infection.

As the majority of urine samples submitted for culture yields a negative result, rapid screening that accurately predicts culture outcome benefits clinicians by reducing the time to result and improves the efficiency of the microbiological laboratory. Automated urinalysis using the IRIS Diagnostics iQ200 Elite (iQ200) analyzer permits just such a fast and large-scale screening. We aimed to predict and thus to reduce negative cultures with a screening algorithm based on iQ200 urinalysis in a tertiary university hospital. In parallel, we evaluated the performance of the iQ200 screen compared to that of Gram stain for sample quality. We screened 1,442 samples submitted for bacterial culture using the iQ200 analyzer; of these samples, 357 (24.8%) had a positive culture result. We identified the absence of microorganisms in the iQ200 screen as the strongest solitary predictor for a negative culture, with a sensitivity of 90.5% (323/357). The algorithm was further improved by performing logistic regression on leukocyte counts, which gave a cutoff of 65 leukocytes/µl to obtain the desired sensitivity of >95% (95.2%; 95% confidence interval [CI], 92.5 to 97.0), a negative predictive value of 97.3% (95% CI, 95.7 to 98.3), and an anticipated culture workload reduction of 44% (95% CI, 41 to 46). Concordance between sample quality based on Gram stain and iQ200 screening was only 72%, which was probably a result of interobserver effect in evaluation of the Gram stain. In conclusion, in our setting, screening by iQ200 proved to be a safe and cost-effective means to provide faster culture results, and it has the added benefit of a more objective evaluation of sample quality.

Changes in cis-regulatory elements of a key floral regulator are associated with divergence of inflorescence architectures.

Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than changes in the encoded proteins. Here, we report a functional comparison of the promoters of homologous FMI genes from Arabidopsis, petunia, tomato and Antirrhinum. Analysis of promoter-reporter constructs in petunia and Arabidopsis, as well as complementation experiments, showed that the divergent expression of leafy (LFY) and the petunia homolog aberrant leaf and flower (ALF) results from alterations in the upstream regulatory network rather than cis-regulatory changes. The divergent expression of unusual floral organs (UFO) from Arabidopsis, and the petunia homolog double top (DOT), however, is caused by the loss or gain of cis-regulatory promoter elements, which respond to trans-acting factors that are expressed in similar patterns in both species. Introduction of pUFO:UFO causes no obvious defects in Arabidopsis, but in petunia it causes the precocious and ectopic formation of flowers. This provides an example of how a change in a cis-regulatory region can account for a change in the plant body plan.

[Thalassaemia diagnostics]. / De diagnostiek van thalassemieën.

The thalassaemias are characterised by quantitative aberrations in the production of the globin chains that make up haemoglobin, and are a subgroup of the haemoglobinopathies. In this LabQuiz we show how thalassaemia carrier status can be indicated in the results of regular laboratory tests, and discuss the laboratory diagnostics that can confirm or rule out thalassaemia. In these two cases we will present a man of Moroccan descent, and two brothers of Filipino descent, all with anaemia and microcytosis. We show it is possible to differentiate between iron-deficiency anaemia and thalassaemia carrier status on the basis of a complete blood count and measurement of ferritin levels, and which laboratory diagnostics can be subsequently performed in order to confirm a suspicion of thalassaemia. The background section discusses the properties and pitfalls of routine laboratory diagnostics for the thalassaemias, and thalassaemia diagnostics in the Dutch newborn screening programme.

LEAFY blossoms.

The LEAFY (LFY) gene of Arabidopsis and its homologs in other angiosperms encode a unique plant-specific transcription factor that assigns the floral fate of meristems and plays a key role in the patterning of flowers, probably since the origin of flowering plants. LFY-like genes are also found in gymnosperms, ferns and mosses that do not produce flowers, but their role in these plants is poorly understood. Here, we review recent findings explaining how the LFY protein works and how it could have evolved throughout land plant history. We propose that LFY homologs have an ancestral role in regulating cell division and arrangement, and acquired novel functions in seed plants, such as activating reproductive gene networks.

Inflorescence development in petunia: through the maze of botanical terminology.

Flowering plants have developed many ways to arrange their flowers. A flower-bearing branch or system of branches is called an inflorescence. The number of flowers that an inflorescence contains ranges from a single flower to endless flower-clusters. Over the past centuries, botanists have classified inflorescences based on their morphology, which has led to an unfortunate maze of complex botanical terminology. With the rise of molecular developmental biology, research has become increasingly focused on how inflorescences develop, rather than on their morphology. It is the decisions taken by groups of stem cells at the growing tips of shoots, called meristems, on when and where to produce a flower or a shoot that specify the course of inflorescence development. Modelling is a helpful aid to follow the consequences of these decisions for inflorescence development. The so-called transient model can produce the broad inflorescence types: cyme, raceme, and panicle, into which most inflorescences found in nature can be classified. The analysis of several inflorescence branching mutants has led to a solid understanding of cymose inflorescence development in petunia (Petunia hybrida). The cyme of petunia is a distinct body plan compared with the well-studied racemes of Arabidopsis and Antirrhinum, which provides an excellent opportunity to study evolutionary developmental biology (evo-devo) related questions. However, thus far, limited use has been made of this opportunity, which may, at least in part, be due to researchers getting lost in the terminology. Some general issues are discussed here, while focusing on inflorescence development in petunia.

Role of EVERGREEN in the development of the cymose petunia inflorescence.

Plants species diverge with regard to the time and place where they make flowers. Flowers can develop from apical meristems, lateral meristems, or both, resulting in three major inflorescence types known as racemes, cymes, and panicles, respectively. The mechanisms that determine a racemose architecture have been uncovered in Arabidopsis and Antirrhinum. To understand how cymes are specified, we studied mutations that alter the petunia inflorescence. Here we show that EVERGREEN (EVG) encodes a WOX homeodomain protein, which is exclusively expressed in incipient lateral inflorescence meristems (IMs), promoting their separation from the apical floral meristem (FM). This is essential for activation of DOUBLE TOP and specification of floral identity. Mutations that change the cymose petunia inflorescence into a solitary flower fully suppress the evg phenotype. Our data suggest a key role for EVG in the diversification of inflorescence architectures and reveal an unanticipated link between the proliferation and identity of meristems.

Patterning of inflorescences and flowers by the F-Box protein DOUBLE TOP and the LEAFY homolog ABERRANT LEAF AND FLOWER of petunia.

Angiosperms display a wide variety of inflorescence architectures differing in the positions where flowers or branches arise. The expression of floral meristem identity (FMI) genes determines when and where flowers are formed. In Arabidopsis thaliana, this is regulated via transcription of LEAFY (LFY), which encodes a transcription factor that promotes FMI. We found that this is regulated in petunia (Petunia hybrida) via transcription of a distinct gene, DOUBLE TOP (DOT), a homolog of UNUSUAL FLORAL ORGANS (UFO) from Arabidopsis. Mutation of DOT or its tomato (Solanum lycopersicum) homolog ANANTHA abolishes FMI. Ubiquitous expression of DOT or UFO in petunia causes very early flowering and transforms the inflorescence into a solitary flower and leaves into petals. Ectopic expression of DOT or UFO together with LFY or its homolog ABERRANT LEAF AND FLOWER (ALF) in petunia seedlings activates genes required for identity or outgrowth of organ primordia. DOT interacts physically with ALF, suggesting that it activates ALF by a posttranslational mechanism. Our findings suggest a wider role than previously thought for DOT and UFO in the patterning of flowers and indicate that the different roles of LFY and UFO homologs in the spatiotemporal control of floral identity in distinct species result from their divergent expression patterns.