A comparison of headnet electrode arrays for electrical impedance tomography of the human head

Three types of commercially available headnet electrode arrays, designed for use in EEG, and conventional EEG Ag/AgCl cup electrodes were tested on human subjects, and a realistic, saline-filled head-shaped tank was prepared with vegetable skin to simulate human skin in order to determine the optimum electrode system for electrical impedance tomography (EIT) of the human head. Impedance changes during EIT acquisition were produced in healthy volunteers during a finger-thumb apposition task and in tanks by the insertion of a Perspex rod. Signal-to-baseline noise, measured from raw EIT data, was 2.3 +/- 0.3 and 2.3 +/- 0.2 for the human and tank data, respectively. In both the human and tank experiments, a commercial hydrogel elasticated electrode headnet produced the least amount of baseline noise, and was the only headnet in the human data with noise levels acceptable for EIT imaging. Image quality measured in the tank was similar for most of the headnets tested, except that the EEG electrodes produced a higher positional error and electrodes in a geodesic elasticated net produced images with worse subjective image quality. Overall, the hydrogel elasticated headnet was judged to be the most suitable for human neuroimaging with EIT.

Radiological versus histological diagnosis in UIP and NSIP: survival implications

BACKGROUND

High resolution computed tomography (HRCT) has an important diagnostic role in idiopathic interstitial pneumonia (IIP). We hypothesised that the HRCT appearance would have an impact on survival in patients with IIP.

METHODS

HRCT scans from patients with histological usual interstitial pneumonia (UIP; n=73) or histological non-specific interstitial pneumonia (NSIP; n=23) were characterised as definite UIP, probable UIP, indeterminate, probable NSIP, or definite NSIP. Cox regression analysis examined the relationships between histopathological and radiological diagnoses and mortality, controlling for patient age, sex, and smoking status.

RESULTS

All 27 patients with definite or probable UIP on HRCT had histological UIP; 18 of 44 patients with probable or definite NSIP on HRCT had histological NSIP. Patients with HRCT diagnosed definite or probable UIP had a shorter survival than those with indeterminate CT (hazards ratio (HR) 2.43, 95% CI 1.06 to 5.58; median survival 2.08 v 5.76 years) or HRCT diagnosed definite or probable NSIP (HR 3.47, 95% CI 1.58 to 7.63; median survival 2.08 v 5.81 years). Patients with histological UIP with no HRCT diagnosis of probable or definite UIP fared better than patients with histological UIP and an HRCT diagnosis of definite or probable UIP (HR 0.49, 95% CI 0.25 to 0.98; median survival 5.76 v 2.08 years) and worse than those with a histological diagnosis of NSIP (HR 5.42, 95% CI 1.25 to 23.5; median survival 5.76 v >9 years).

CONCLUSIONS

Patients with a typical HRCT appearance of UIP experience the highest mortality. A surgical lung biopsy is indicated for patients without an HRCT appearance of UIP to differentiate between histological UIP and NSIP.

Novel antisense oligonucleotides targeting TGF-beta inhibit in vivo scarring and improve surgical outcome

The scarring response is an important factor in many diseases throughout the body. In addition, it is a major problem in influencing results of surgery. In the eye, for example, post-operative scarring can determine the outcome of surgery. This is particularly the case in the blinding disease glaucoma, where several anti-scarring regimens are currently used to improve glaucoma surgery results, but are of limited use clinically because of severe complications. We have recently identified transforming growth factor-beta (TGF-beta) as a target for post-operative anti-scarring therapy in glaucoma, and now report the first study of novel second-generation antisense phosphorothioate oligonucleotides against TGF-beta in vivo. Single applications of a TGF-beta OGN at the time of surgery in two different animal models closely related to the surgical procedure performed in glaucoma patients, significantly reduced post-operative scarring (P<0.05) and improved surgical outcome. Our findings suggest that TGF-beta antisense oligonucleotides have potential as a new therapy for reducing post-surgical scarring. Its long-lasting effects after only a single administration at the time of surgery make it particularly attractive clinically. Furthermore, although we have shown this agent to be useful in the eye, it could have widespread applications anywhere in the body where the wound-healing response requires modulation.

Effect of in vivo administration of anti-CTLA-4 monoclonal antibody and IL-12 on the induction of low-dose oral tolerance

Oral tolerance has been characterized as an immunological hyporesponsiveness to fed antigen. Previous studies have suggested that high-dose oral tolerance involves the preferential interaction of B7 with CTLA-4 on the T cell. To determine whether similar mechanisms are involved in the induction of low-dose oral tolerance, mice were treated with anti-CTLA-4 monoclonal antibody (MoAb), with or without IL-12, at the time of feeding. Results showed that anti-CTLA-4 MoAb alone failed to restore cellular proliferation, antibody titres and IFN-gamma levels; however, IL-4 cytokine levels in OVA-fed mice were partially restored. In contrast, administration of IL-12 along with anti-CTLA-4 MoAb to mice during feeding completely prevented the suppression of Th1 immune responses, as shown by increased serum IgG2a titres, IFN-gamma production and cell proliferation. These results suggest that blocking B7-CTLA-4 interactions in the presence of IL-12 prevents the induction of low-dose oral tolerance at the Th1 cell level.

Changes in prevalence and treatment need for traumatic dental injuries among 14-year-old children in Newham, London: a deprived area

OBJECTIVE

The study was carried out to assess the prevalence of traumatic injuries to the permanent incisors of 14-year-old schoolchildren in Newham in 1998-99, the treatment needed and to compare the results with data from 1995-96. Also, to test whether different levels of deprivation within an area would increase the risk of dental injury.

BASIC RESEARCH DESIGN

A cross-sectional study was carried out. One dentist (SM) carried out all dental examinations. Upper and lower permanent incisors were examined for dental injuries. The examiner recorded the type of damage sustained, any treatment carried out and the treatment need.

PARTICIPANTS

411 14-year-old schoolchildren in Newham in 1998-99. Results The prevalence of traumatic injuries was 43.8% (95% CI 39.0, 48.7) in 1998-99, compared to 23.7% (95% CI 22.0, 25.5) in 1995-96. Boys sustained statistically significantly more dental injuries than girls, 50.2% and 37.1% respectively (P<0.01). In 1998-99 92.7 per thousand incisors were damaged, 6.7 per thousand incisors were treated and 28.9 per thousand incisors needed treatment. Two components of the Jarman Index were associated with dental injuries. Overcrowded household was statistically significantly related to dental injuries in both studies. Ethnicity was associated with dental injury in 1998-99, but not tested in 1995-96. CONCLUSIONS The prevalence of traumatic dental injury in Newham increased from 23.7% to 43.8% between 1995-96 and 1998-99, it was higher than the overall prevalence in the United Kingdom (17%) and its treatment had been neglected. Area-based measures of deprivation such as an overcrowded household and ethnicity were predictors of traumatic dental injuries.

Suspected pulmonary embolism in pregnancy: clinical presentation, results of lung scanning, and subsequent maternal and pediatric outcomes

BACKGROUND

Ventilation-perfusion (VQ) scanning is used when pulmonary embolism (PE) is suspected during pregnancy; however, the distribution of lung scan results and safety of VQ scanning have never been studied.

OBJECTIVE

To study the distribution of lung scan results and safety of VQ scanning as well as the safety of withholding anticoagulation therapy following a normal or nondiagnostic scan in pregnant women.

METHODS

The study group comprised 120 consecutive pregnant women who presented with suspected PE. Clinical data were collected, and the lung scans were reinterpreted by 2 independent experts. Subsequent pregnancy and pediatric outcomes were determined by direct patient follow-up.

RESULTS

During the study period, 120 pregnant women (mean age, 32 years) underwent 121 VQ scans. Eight cases (6.6%) were already receiving treatment for venous thromboembolism prior to VQ scanning. In the remaining 113 scans, 83 (73.5%) were interpreted as normal, 28 (24.8%) as nondiagnostic, and 2 (1.8%) as high probability. In the 104 women who did not receive anticoagulation therapy following lung scanning (80 normal and 24 nondiagnostic), no venous thromboembolic events were reported (mean [range] length of follow-up, 20.6 [0.5-108] months). Examination of pediatric data from 110 live births (90.2%) (mean [range] age, 20.5 [0.5-100] months) revealed no increase in the rates of congenital and developmental anomalies.

CONCLUSIONS

The prevalence of high-probability VQ scans in pregnant women with suspected PE and probable PE is very low. Withholding anticoagulation in pregnant women with normal or nondiagnostic VQ scans is probably safe. In addition, pediatric risks from VQ scans are low. Large prospective studies are needed to evaluate diagnostic strategies for pregnant women with suspected PE.

Targeted pharmacological depletion of serum amyloid P component for treatment of human amyloidosis

The normal plasma protein serum amyloid P component (SAP) binds to fibrils in all types of amyloid deposits, and contributes to the pathogenesis of amyloidosis. In order to intervene in this process we have developed a drug, R-1-[6-[R-2-carboxy-pyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid, that is a competitive inhibitor of SAP binding to amyloid fibrils. This palindromic compound also crosslinks and dimerizes SAP molecules, leading to their very rapid clearance by the liver, and thus produces a marked depletion of circulating human SAP. This mechanism of drug action potently removes SAP from human amyloid deposits in the tissues and may provide a new therapeutic approach to both systemic amyloidosis and diseases associated with local amyloid, including Alzheimer's disease and type 2 diabetes.

Gamma-hydroxybutyric acid: patterns of use, effects and withdrawal

Gamma-hydroxybutyric acid (GHB) is gaining popularity as a drug of abuse. Reports of toxicity and lethality associated with GHB use have increased. This survey study was designed to identify patterns of GHB use, its effects, and withdrawal syndrome. A survey inquiring about the effects of GHB was administered to 42 users. The results showed that GHB was used to increased feelings of euphoria, relaxation, and sexuality. Adverse effects occurred more frequently in daily users and polydrug users than in occasional GHB users. Loss of consciousness was reported by 66%, overdose by 28%, and amnesia by 13% of participants during GHB use and by 45% after GHB use. Three daily users developed a withdrawal syndrome that presented with anxiety, agitation, tremor, and delirium. Participants described GHB intoxication as having similarities to sedative-hypnotic or alcohol intoxication. Regular use has been shown to produce tolerance and dependence. Participants dependent on GHB reported using multiple daily doses around the clock. High frequency users appeared at the greatest risk for developing withdrawal delirium and psychosis after abrupt discontinuation of GHB use.

Development and application of a sensitive high performance ion-exchange chromatography method for the simultaneous measurement of dopamine, 5-hydroxytryptamine and norepinephrine in microdialysates from the rat brain

A high performance liquid chromatography (HPLC) method based on cation exchange separation has been developed for the measurement of dopamine (DA), 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in microdialysates. The separation conditions have been optimised for using electrochemical detection. All three bioamines were resolved in less than 22 min using isocratic conditions. The optimum oxidation potential for the three bioamines was found to be +0.4 V vs. in situ Ag/AgCl reference electrode. Linear regression analysis of HPLC-peak area as a function of concentrations in the range 1-50 ng x ml(-1) gave coefficients of correlation between 0.998 and 0.999. The limit of detection for DA, 5-HT and NE was found to be between 50 and 100 pg x ml(-1) with a signal to noise ratio of 3:1. The method has been applied to the simultaneous measurement of the three monoamines in microdialysates from the medial prefrontal cortex under basal conditions and following the administration of the antipsychotic drug clozapine (10 mg x kg(-1) s.c.).

Pre- and post-test evaluation of a project to facilitate research development in practice in a hospital setting

BACKGROUND

This paper describes a project designed to facilitate the use of research in nursing practice in one acute hospital. A university team worked in collaboration with staff from the hospital to develop and evaluate the impact of development work designed to enhance knowledge and use of research in practice.

DESIGN/METHODS

A research utilization questionnaire was administered as a pre-test (stage 1); a development phase was implemented (stage 2) and a post-test survey (stage 3) was administered to evaluate the impact of the development work. In stage 1, the total population of nursing and midwifery staff in the hospital (n=473) were targeted and 235 returned the questionnaire, giving a response rate of 50%. Data from the pre-test and focus group discussions with staff were used to plan stage 2 of the project. The development stage involved an educational strand in which open learning research materials were made available to staff, who were also offered tutorial support in their learning. A second strand supported the development of clinical research projects and funds were identified for clinical staff to apply for project development awards to enable them to develop skills in research and development activity under the supervision of a research fellow. Stage 3 involved a post-test survey of staff who had completed the questionnaire in stage 1 (n=81).

FINDINGS

There were no significant differences in findings between the pre-test and post-test. Qualitative data from those involved in the clinical projects in stage 2 indicated factors impacting on the feasibility of undertaking research in practice.

Diazinon is activated by CYP2C19 in human liver

Phosphorothioate compounds are used throughout the world as agricultural and domestic pesticides. Here, the activation of the phosphorothioate diazinon to diazoxon in human liver is described. In an initial study using three human liver microsomal samples, K(m) for diazoxon formation varied markedly (31, 208, and 660 microM; V(max) 1125, 685, and 1028 pmol/min/mg protein, respectively), suggesting the involvement of more than one P450 enzyme. A wide variation in activity was found using 50 microM diazinon as substrate, (11-648 pmol/min/mg protein, n = 15), whereas, with 500 microM, variation was less (164-978 pmol/min/mg protein). Among eight P450-catalyzed reactions, the putative high-affinity component (50 microM diazinon) correlated with S-mephenytoin 4'-hydroxylase activity (r = 0.686, p < 0.01), suggesting the involvement of CYP2C19. The putative low-affinity component (500 microM diazinon) correlated with both S-mephenytoin 4'-hydroxylase (r = 0.714; p < 0.005) and high-affinity phenacetin O-deethylase activity (r = 0.625; p < 0.05). This activity was partially inhibited by furafylline, troleandomycin, and ketoconazole. These data suggest contributions from CYP2C19, CYP1A2, and CYP3A4. None of the inhibitors affected the high-affinity component. Of seven heterologously expressed human P450 enzymes, CYP2C19 activated diazinon (500 microM) at the fastest rate, followed by CYP3A4, CYP1A2, and CYP2C9. Both hepatic microsomal S-mephenytoin 4'-hydroxylase and high-affinity phenacetin O-deethylase activities were strongly inhibited by diazinon (IC50 < 2.5 microM), while no effect was seen on midazolam 1'-hydroxylase activity. These data indicate that CYP2C19 is the major enzyme involved in diazinon activation in human liver, while other enzymes including CYP1A2 may play a more minor role.

Liquid meal replacements and glycemic control in obese type 2 diabetes patients

OBJECTIVE

Although weight management is an important component in the treatment of type 2 diabetes, there has been concern about the use of liquid meal replacements (MRs) in treating obese patients with type 2 diabetes because of the sugar content of the MRs. The goal of this study was to evaluate the safety and feasibility of using MRs for weight loss in obese patients with type 2 diabetes.

RESEARCH METHODS AND PROCEDURES

Seventy-five subjects with type 2 diabetes, treated only with oral agents, were recruited for this 12-week clinical study. Subjects were randomized into three groups using either a MR containing lactose, fructose, and sucrose, a MR in which fructose and sucrose were replaced with oligosaccharides (sugar-free Slim-Fast), or an exchange diet plan (EDP) using the proportion of macronutrients recommended by the American Diabetes Association.

RESULTS

Fifty-seven patients (41 MR and 16 EDP) finished the study. None developed serious adverse effects, including major hypoglycemic reactions. Weight losses in the MR 1 and MR 2 groups were comparable (6.4% and 6.7%, respectively) and greater than the weight loss in the EDP group (4.9%). Fasting glucose level was significantly reduced in the MR group compared with the EDP group (p = 0.012). There was a significant reduction in the MR group in total cholesterol and low-density lipoprotein cholesterol that was not seen in the EDP group.

DISCUSSION

We have shown that liquid MRs are a safe and effective weight loss tool for obese subjects with type 2 diabetes, and can result in improvements in body weight, glucose, insulin, hemoglobin A1c and lipid levels.

Analysis of the glutathione conjugate of paracetamol in human liver microsomal fraction by liquid chromatography mass spectrometry

An assay based on microbore liquid chromatography-positive ion electrospray mass spectrometry with selected ion recording has been developed for the measurement of the glutathione conjugate of paracetamol (acetaminophen) in human hepatic microsomal incubations. A deuterated analogue of the glutathione conjugate was synthesized for use as an internal standard and extraction was carried out on Oasis solid phase extraction columns. The limit of quantification of the glutathione conjugate was 10 ng/incubation and the intra-assay coefficient of variation at this concentration was 6.8%.

Developing A&E nursing responses to people who deliberately self-harm: the provision and evaluation of a series of reflective workshops

Accident & Emergency (A&E) departments and Medical Admission Units (MAUs) are an essential part of emergency mental health care in the UK. Deliberate self-harm and attempted suicide are particular challenges to nursing staff in such departments. Two registered mental nurses with experience of education facilitated a series of workshops with nurses from four A&E departments, two Minor Injuries Units and two MAUs. These were focused upon the assessment and management of deliberate self-harm and attempted suicide. During the workshops, participants provided systematic information on presentations of deliberate self-harm and attempted suicide, and on their professional responses to such presentations. These accounts provided invaluable information on deliberate self-harm and attempted suicide as seen by nursing staff in A&E and MAUs. Critical reflection upon nursing responses to these presentations revealed particular concerns nurses had relating to their experience with this client group which might inform future practice. Evaluation of the workshops indicated a subsequent decrease in work-related stress, which was probably a consequence of improved professional coping responses by the nurses concerned.

Cancer-specific worry interference in women attending a breast and ovarian cancer risk evaluation program: impact on emotional distress and health functioning

Intrusive thoughts about cancer, often identified as 'cancer-specific worries' or 'cancer-specific distress', have been postulated to be associated with dysfunction in women at increased risk of developing breast or ovarian cancer. The current study discusses the development and validation of a measure designed to assess women's perceptions of the interference such worries create in their daily functioning. Analyses revealed that approximately two-thirds of a high-risk breast cancer clinic sample perceived worries about breast cancer as interfering with their functioning across a variety of life domains. Multiple regression analyses indicated that worry interference scores predicted Profile of Mood States (POMS) Anxiety and Confusion, and Short Form-36 (SF-36) Role-Emotional and Mental Health scores after the effects of other variables such as frequency of worry about breast cancer, and having a family history of cancer had been considered. Women who perceived their worries as interfering with their functioning reported higher levels of anxiety and confusion, and diminished mental health and role functioning. The results add to the expanding area of anxiety/distress in at-risk populations by providing (1) a direct measure of the perceived interference associated with breast cancer-specific thoughts, (2) a validation of the measure via its associations with standard measures of emotional distress and health functioning, and (3) evidence of the measure's incremental predictive value in explaining distress and quality of life, after consideration of background variables, such as having a family history of cancer.

Assessment of early continence recovery after radical prostatectomy: patient reported symptoms and impairment

PURPOSE

Patients considering radical prostatectomy often inquire as to when they can expect to regain urinary continence. However, there is a paucity of patient self-reported data regarding the recovery of continence during the initial 3 months after surgery. Our objectives were to assess urinary continence changes early in the postoperative period and determine which of 2 commonly used definitions of continence more closely relate to patient reported urinary impairment.

MATERIALS AND METHODS

A prospective study of 90 men with clinically localized prostate cancer who selected radical prostatectomy as primary therapy was conducted. Repeated measures of urinary continence as defined by 1) total urinary control, 2) the use of 1 or 0 pads daily, and 3) small or no problem with urinary function were obtained with a brief survey preoperatively and postoperatively.

RESULTS

At 56 days after removal of urethral catheters, the actuarial rates of urinary continence recovery based on definitions 1 to 3 were 43%, 84% and 82%, respectively. The use of definition 2 for continence resulted in a 1.9 times higher actuarial rate for continence recovery when compared to definition 1 at 56 days (p <0.001). However, strong agreement was observed between definitions 2 and 3 (kappa = 0.69).

CONCLUSIONS

Urinary control is recovered in a significant proportion of men who undergo radical prostatectomy during the initial 3 months. Continence rates will vary significantly based on the use of alternative definitions. The clinical practice of asking patients how many pads daily they use may be valid, as it corresponds well to the impairment they have.

Personality profile and neuropsychological test performance in chronic cocaine-abusers

Little is known about the association between personality disorders and neuropsychological test performance in chronic cocaine users. The aims of the present study were to (1) pinpoint the specific neuropsychological characteristics of chronic cocaine abusers, (2) analyze their personality profile, and (3) explore the association between personality traits and neuropsychological test performance. A sample of 42 drug-abusers (mean age = 34.15; SD = 6.73; mean educational level = 11.44; SD = 2.01) was selected from a state rehabilitation facility and was compared to a control group (mean age = 34.53; SD = 9.01; mean educational level = 12.29; SD = 1.31). The following information was collected for each subject: (1) A clinical history adapted from Horton (1996). (2) The Personality Assessment Inventory (PAI) (Morey, 1991). (3) A neuropsychological test battery including: Arithmetic and Digits subtests from the WAIS-R, California Verbal Learning Test, Trial Making Test, Verbal Fluency tests, Rey-Osterrieth Complex Figure, Wisconsin Card Sorting Test, Benton Visual Retention Test, Stroop Neurological Screening Test and Hooper Visual Organization. Thirty-seven of the drug-dependent subjects obtained an abnormal score in at least one PAI scale. The personality profile of the drug-dependent subjects found via the PAI pointed to a Borderline/Antisocial personality, frequently associated with mania features. In six of the drug-abusers, a normal personality profile was observed. Neuropsychological test performance scores were within the low average or borderline range. The most abnormal scores were observed in attention, memory, and executive functioning tests. The results did not show any robust association between personality profile and neuropsychological test performance.

Effect of cruciferous vegetable consumption on heterocyclic aromatic amine metabolism in man

The consumption of cooked meat appears to predispose individuals to colonic cancer and heterocyclic aromatic amines (HA), formed during the cooking of meat, have been suggested as aetiological agents. Consumption of cruciferous vegetables is thought to protect against cancer. To study the effect of cruciferous vegetables on heterocyclic aromatic amine metabolism in man, a three-period, dietary intervention study has been carried out with 20 non-smoking Caucasian male subjects consuming cooked meat meals containing known amounts of these carcinogens. A high cruciferous vegetable diet (250 g each of Brussels sprouts and broccoli per day) was maintained during period 2 but such vegetables were excluded from periods 1 and 3. At the end of each period, subjects consumed a cooked meat meal and urinary excretion of the HA 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) was measured. Following a 12 day period of cruciferous vegetable consumption (period 2), induction of hepatic CYP1A2 activity was apparent from changes in the kinetics of caffeine metabolism. Excretion of MeIQx and PhIP in urine at the end of this period of the study was reduced by 23 and 21%, respectively, compared with period 1. This reduction in excretion is probably due to an increase in amine metabolism that might be expected given the observed increase in CYP1A2 activity, since this enzyme has been shown to be primarily responsible for the oxidative activation of MeIQx and PhIP in man. In period 2, urinary mutagenicity was increased relative to period 1 by 52 and 64% in the absence and presence, respectively, of a human liver microsomal activation system, yet no evidence was found of PhIP adduction to lymphocyte DNA, a potential biomarker of the activation process. After another 12 days without cruciferous vegetables (period 3 of the study), the kinetics of caffeine metabolism had returned to original values but excretion of MeIQx and PhIP was still reduced by 17 and 30%, respectively, and urinary mutagenicity (with metabolic activation) was still elevated compared with period 1. This prolonged response of amine metabolism to the cruciferous vegetable diet, shown especially with PhIP, suggests that enzyme systems other than CYP1A2 are involved and affected by a cruciferous vegetable diet.

Rapid urinalysis assays for the diagnosis of urinary tract infection

Urinary tract infection (UTI) in premenopausal women is a frequent complaint in general practice. UTI is usually diagnosed on the basis of clinical symptoms and the use of one or more laboratory tests, the most common being rapid urinalysis reagent assays (urine dip) or midstream urine culture. In order to correlate the leucocyte esterase results of a rapid urinalysis assay with direct urine microscopy for pyuria, undiluted non-centrifuged urine samples from 206 volunteer female healthcare professionals were subjected to analysis using direct urine microscopy using a counting chamber and a rapid urinalysis assay. Of the 206 specimens, 74 were positive for leucocyte esterase using the rapid urinalysis assay, and 39 specimens demonstrated significant pyuria (greater than or equal to 10 leucocytes/microl) on direct microscopy. When the leucocyte esterase results were correlated with the direct urine microscopy results, an assay reading of 15 leucocytes/microl ('trace' on the visual scale) had a sensitivity of 91%, specificity of 79%, positive predictive value of 53% and a negative predictive value of 97%. An assay reading of 25 leucocytes/microl ('+' on the visual scale) or greater had a sensitivity of 63%, specificity of 95%, positive predictive value of 75% and a negative predictive value of 91%. In premenopausal, non-pregnant females, a rapid urinalysis assay result of 25 leucocytes/microl or greater will predict significant pyuria on urine microscopy with reasonable confidence, thereby reducing the need for more costly urine cultures.