Identifying predictors of varices grading in patients with cirrhosis using ensemble learning.

OBJECTIVES: The present study was conducted to improve the performance of predictive methods by introducing the most important factors which have the highest effects on the prediction of esophageal varices (EV) grades among patients with cirrhosis. METHODS: In the present study, the ensemble learning methods, including Catboost and XGB classifier, were used to choose the most potent predictors of EV grades solely based on routine laboratory and clinical data, a dataset of 490 patients with cirrhosis gathered. To increase the validity of the results, a five-fold cross-validation method was applied. The model was conducted using python language, Anaconda open-source platform. TRIPOD checklist for prediction model development was completed. RESULTS: The Catboost model predicted all the targets correctly with 100% precision. However, the XGB classifier had the best performance for predicting grades 0 and 1, and totally the accuracy was 91.02%. The most significant variables, according to the best performing model, which was CatBoost, were child score, white blood cell (WBC), vitalism K (K), and international normalized ratio (INR). CONCLUSIONS: Using machine learning models, especially ensemble learning models, can remarkably increase the prediction performance. The models allow practitioners to predict EV risk at any clinical visit and decrease unneeded esophagogastroduodenoscopy (EGD) and consequently reduce morbidity, mortality, and cost of the long-term follow-ups for patients with cirrhosis.

Prevalence and predictors of complementary and alternative medicine/non-pharmacological interventions use for menopausal symptoms within the UK Collaborative Trial of Ovarian Cancer Screening.

OBJECTIVES: The negative publicity about menopausal hormone therapy (MHT) has led to increased use of complementary and alternative medicines (CAM) and non-pharmacological interventions (NPI) for menopausal symptom relief. We report on the prevalence and predictors of CAM/NPI among UK postmenopausal women. METHOD: Postmenopausal women aged 50-74 years were invited to participate in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS). A total of 202 638 women were recruited and completed a baseline questionnaire. Of these, 136 020 were sent a postal follow-up-questionnaire between September 2006 and May 2009 which included ever-use of CAM/NPI for menopausal symptom relief. Both questionnaires included MHT use. RESULTS: A total of 88 430 (65.0%) women returned a completed follow-up-questionnaire; 22 206 (25.1%) reported ever-use of one or more CAM/NPI. Highest use was reported for herbal therapies (43.8%; 9725/22 206), vitamins (42.6%; 9458/22 206), lifestyle approaches (32.1%; 7137/22 206) and phytoestrogens (21.6%; 4802/22 206). Older women reported less ever-use of herbal therapies, vitamins and phytoestrogens. Lifestyle approaches, aromatherapy/reflexology/acupuncture and homeopathy were similar across age groups. Higher education, Black ethnicity, MHT or previous oral contraceptive pill use were associated with higher CAM/NPI use. Women assessed as being less hopeful about their future were less likely to use CAM/NPI. CONCLUSION: One in four postmenopausal women reported ever-use of CAM therapies/NPI for menopausal symptom relief, with lower use reported by older women. Higher levels of education and previous MHT use were positive predictors of CAM/NPI use. UKCTOCS Trial registration: ISRCTN22488978.

Does anti-Müllerian hormone predict menopause in the general population? Results of a prospective ongoing cohort study.

STUDY QUESTION: Do ovarian reserve tests (ORTs) predict age at natural menopause (ANM) in a cohort of healthy women with a regular menstrual cycle? SUMMARY ANSWER: Of the ORTs researched, anti-Müllerian hormone (AMH) alone predicts age at menopause. However, its predictive value decreased with increasing age of the woman, prediction intervals were broad and extreme ages at menopause could not be predicted. WHAT IS KNOWN ALREADY: A fixed interval is hypothesized to exist between ANM and age at loss of natural fertility. Therefore, if it is possible to predict ANM, one could identify women destined for early menopause and thus at higher risk for age-related subfertility. Of ORTs researched in the prediction of ANM, AMH is the most promising one. STUDY DESIGN, STUDY SIZE AND DURATION: A long-term, extended follow-up study was conducted, results of the first follow-up round were previously published. Two hundred and sixty-five normo-ovulatory women (21-46 years) were included between 1992 and 2001, 49 women (18.5%) could not be reached in the current follow-up round. PARTICIPANTS, SETTING, METHODS: Two hundred and sixty-five healthy normo-ovulatory women were included, recruited in an Academic hospital. We measured baseline AMH, follicle-stimulating hormone and the antral follicle count (AFC). At follow-up (2009 and 2013), menopausal status was determined via questionnaires. Cox regression analysis calculated time to menopause (TTM) using age and ORT. A check of (non-) proportionality of the predictive effect of AMH was performed. A Weibull survival model was used in order to predict individual ANM. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 155 women were available for analyses. Eighty-one women (37.5%) had become post-menopausal during follow-up. Univariable Cox regression analysis demonstrated age and ORTs to be significantly correlated with TTM. Multivariable Cox regression analysis, adjusting for baseline age and smoking; however, demonstrated AMH alone to be an independent predictor of TTM (Hazard Ratio 0.70, 95% Confidence Interval 0.56-0.86, P-value <0.001). A (non-)proportionality analysis of AMH over time demonstrated AMH's predictive effect to decline over time. LIMITATIONS, REASON FOR CAUTION: The observed predictive effect of AMH became less strong with increasing age of the woman. Individual AMH-based age at menopause predictions did not cover the full range of menopausal ages, but did reduce the variation around the predicted ANM from 20 to 10.1 years. WIDER IMPLICATIONS OF THE FINDINGS: Age-specific AMH levels are predictive for ANM. Unlike in our previous publication however, a declining AMH effect with increasing age was observed. This declining AMH effect is in line with recent long-term follow-up data published by others. Moreover, the accompanying predictive inaccuracy observed in individual age at menopause predictions based on AMH, makes this marker currently unsuitable for use in clinical practice. STUDY FUNDING/COMPETING INTERESTS: No external funds were used for this study. M.D., M.J.C.E, S.L.B., G.J.S. and I.A.J.R. have nothing to declare. J.S.E.L. has received fees and grant support from the following companies (in alphabetical order): Ferring, Merck-Serono, MSD, Organon, Serono and Schering Plough. F.J.M.B. receives monetary compensation: member of the external advisory board for Merck Serono, the Netherlands; consultancy work for Gedeon Richter, Belgium; educational activities for Ferring BV, the Netherlands; strategic cooperation with Roche on automated AMH assay development.

Buerger's disease in the northeast of Iran: Epidemiology and clinical features.

BACKGROUND: The aim of this study is to present our long-term clinical experience in describing a clinical picture of Buerger's disease in our region. MATERIALS AND METHODS: In a retrospective study, files of 225 patients who were admitted to the hospital with diagnosis of thromboangiitis obliterans in a 10 year period from 2000 to 2010 were reviewed. All data including demographic, signs and symptoms, history of previous illness, history of smoking, medications, laboratory tests, angiography, and details of surgical operation were obtained. RESULTS: A total of 222 (98.7%) and 3 (1.3%) of patients were male and female, respectively. Average age of hospitalized patients was 40.7 ± 8.5 (20-62) years. A total of 200 patients (88.9%) were active cigarette smokers while 168 (74.7%) of them were opium addicts. The most prevalent symptoms were chronic ulcers (80%) and claudication (63.6%). Minor and major amputation was required in 113 (50.2%) and 41 (18.4%) patients, respectively. Amputation was carried out on the lower limb (80%), upper limb (4.1%), or on both (15.1%). Also, four patients underwent revascularization through surgical bypass procedures. CONCLUSIONS: The diagnosis and treatment of Buerger's Disease is still a challenge in those communities where the disease is endemic. Therefore, identifying the natural course of the disease can play a pivotal role in the diagnosis and treatment of these patients.

Utility of opium seed extract tests in preventing hypersensitivity reactions during surgery.

BACKGROUND: Anaphylaxis during anaesthesia is fatal in 3-9% of patients and analgesics, including opioids, and is the second most common medicament-related cause, although the prevalence is underestimated. We recently found that patients may generate IgE antibodies to opium seeds. OBJECTIVES: To determine the diagnostic accuracy of specific antibodies to morphine, codeine, rocuronium and oil body and aqueous fractions of Papaver somniferum seeds in the diagnosis and prevention of allergy to opioids. METHODS: Patients with hypersensitivity reactions during surgery, and severe clinical allergy (pollen, tobacco), and illicit heroin users were selected. The sensitivity, specificity and predictive values of in vivo and in vitro diagnostic techniques including oil body and aqueous fractions of P. somniferum seeds were measured. RESULTS: We studied 203 patients, with mean age 35.1±17.1 and 200 healthy controls. Patients sensitised to heroin or with hypersensitivity reactions during surgery responded to P. somniferum seed tests. Of patients not known to be sensitised to opioids, the highest positivity was in patients sensitised to tobacco (p<0.001). Opium seed skin tests and IgE, especially the oil body fraction, were more sensitive (64.2%) and specific (98.4%) than morphine, codeine and rocuronium tests for opioid sensitivity. Pollen allergy was not a risk factor for sensitisation to morphine. CONCLUSIONS: Sensitivity to opioids and intraoperative anaphylaxis can be diagnosed by routine tests. IgE and skin tests for the oil body fraction of P. somniferum had the highest sensitivity for sensitisation to opioids.

Pattern and predictors of complementary and alternative medicine (CAM) use among pediatric patients with epilepsy.

Parents of pediatric patients with chronic conditions such as epilepsy increasingly opt for complementary and alternative medicine (CAM). However, data on the pattern and reasons of CAM use in childhood epilepsy are scarce. The objectives of this study were as follows: first, to characterize CAM use among pediatric patients with epilepsy by assessing its spectrum, prevalence, costs, and frequency of use; second, to evaluate the influence of CAM use on compliance and satisfaction with conventional care as well as to explore parent-child neurologist communication concerning CAM; and third, to investigate predictors of CAM use. A postal survey was administered to all parents of pediatric outpatients with epilepsy aged 6 to 12, who have received treatment at the neuropediatric outpatient clinic of the University Children's Hospital Heidelberg between 2007 and 2009. One hundred thirty-two of the 297 distributed questionnaires were suitable for inclusion in statistical analysis (44.7%). Forty-nine participants indicated that their children used CAM during the previous year (37.1%). Thirty different types of CAM were used, with homeopathy (55.1%), osteopathy (24.5%), and kinesiology (16.3%) being the most commonly named. A mean of 86€ (0€-500€) and 3h (1 h-30 h) per month was committed to CAM treatment. Only 53% of the users informed their child neurologist of the additional CAM treatment, while 85.6% of all parents wished to discuss CAM options with their child neurologist. Seventy-five percent of users considered the CAM treatment effective. Among the participants most likely to seek CAM treatment are parents whose children show a long duration of epileptic symptoms, parents who make use of CAM treatment themselves, and parents who value a holistic and natural treatment approach. A substantial portion of pediatric patients with epilepsy receive CAM treatment. The high prevalence of use and significant level of financial and time resources spent on CAM indicate the high importance of these treatment options for parents. On the other hand, communication concerning CAM with the child neurologist is largely insufficient despite the wish to speak about CAM. Complementary and alternative medicine users' high compliance with conventional treatment and high perceived effectiveness of CAM support an integrative approach to CAM for pediatric patients with epilepsy. Our study implies that in addition to open parent-child neurologist communication, active inquiry on CAM treatments is necessary to enable informed decision making by parents and to establish the suitability of CAM treatment for the patient. Reliable predictors for CAM use, which allow for improved identification of patients with a high likelihood to receive CAM treatment, are the duration of the illness, use of CAM by the parents themselves, and the desire of the parents to receive a holistic and natural treatment for their child.

Clinical value of morphine, pholcodine and poppy seed IgE assays in drug-abusers and allergic people.

BACKGROUND: The diagnosis of anaphylactic reactions due to opiates during anaesthesia can be difficult, since in most cases various drugs may have been administered. Detection of specific IgE to poppy seed might be a marker for sensitisation to opiates in allergic people and heroin-abusers. This study assessed the clinical value of morphine, pholcodine and poppy seed skin-prick and IgE determination in people suffering hypersensitivity reactions during anaesthesia or analgesia and drug-abusers with allergic symptoms. METHODS: We selected heroin abusers and patients who suffered severe reactions during anaesthesia and analgesia from a database of 23,873 patients. The diagnostic yield (sensitivity, specificity and predictive value) of prick and IgE tests in determining opiate allergy was analysed. RESULTS: Overall, 149 patients and 200 controls, mean age 32.9 ± 14.7 years, were included. All patients with positive prick to opiates showed positive prick and IgE to poppy seeds, but not to morphine or pholcodine IgE. Among drug-abusers, 13/42 patients (31%) presented opium hypersensitivity confirmed by challenge tests. Among non-drug abusers, sensitisation to opiates was higher in people allergic to tobacco (25%), P<.001. Prick tests and IgE against poppy seed had a good sensitivity (95.6% and 82.6%, respectively) and specificity (98.5% and 100%, respectively) in the diagnosis of opiate allergy. CONCLUSIONS: Opiates may be significant allergens. Drug-abusers and people sensitised to tobacco are at risk. Both the prick and specific IgE tests efficiently detected sensitisation to opiates. The highest levels were related to more-severe clinical profiles.

Neglected foreign body aspiration mimicking bronchial carcinoma.

Foreign body aspiration can occur in any age group, but it is more commonly seen in children. In adults, there is usually a predisposing condition that poses a risk of aspiration. If aspiration occurs, prompt diagnosis and extraction of the foreign body is needed to prevent early and late complications. We report a rare case of neglected foreign body aspiration in a 45-year-old schizophrenic opium addicted patient, which resulted in an occlusive lesion in the bronchus, mimicking bronchial carcinoma.

Predictors of transitions in vitality: the italian longitudinal study on aging.

It is widely acknowledged that there is a strong need to identify which modifiable risk factors predict healthy aging to use this information as the scientific basis for systematic interventions. Data from a 4-year longitudinal study on aging among 5632 older Italians were used. The definition of vitality was based on both cognitive and physical status, and the envisaged transitions were: positive or nonpositive stable, positive or negative transition, lost, and deceased. Predictors associated with different vitality trajectories were investigated by multinomial logistic analysis with a six-level outcome. Age and educational level were predictors of being "positive stable," whereas the other factors behaved differently according to comparison group. For example, being overweight is a common predictor except when compared to the deceased group, as is depressive symptomatology except when compared to the "positive transition" group. Interventions are warranted to reduce social inequalities, promote adequate body weight, and prevent and treat depressive symptoms.

A latex D-dimer reliably excludes venous thromboembolism.

BACKGROUND: D-Dimer, a cross-linked fibrin degradation product, has a high sensitivity in patients with suspected venous thrombosis. Traditional latex D-dimer assays, however, have not been sufficiently sensitive to exclude venous thromboembolism. METHODS: To determine the clinical utility of a latex D-dimer assay (MDA D-Dimer; Organon Teknika Corporation, Durham, NC) in patients with suspected venous thromboembolism, we conducted a retrospective cohort study involving 595 unselected patients at 4 tertiary care hospitals. Patients had blood drawn for performance of the D-dimer assay and underwent objective testing for venous thromboembolism. Pretest probability was determined using validated models in 571 patients. Patients were classified as venous thromboembolism positive or negative according to results of objective tests and 3-month follow-up. The sensitivities, specificities, predictive values, and negative likelihood ratios of the assay were calculated for all patients and for subgroups of patients with known cancer or a low, moderate, or high pretest probability of venous thromboembolism. RESULTS: The prevalence of venous thromboembolism was 19.0% (113/595). Of those who had a pretest probability assessment, 35.9% had a low pretest probability, 49.7% a moderate pretest probability, and 14.4% a high pretest probability. Using a discriminant value of 0.50 microg fibrinogen equivalent units per milliliter, the assay showed an overall sensitivity of 96%, a negative predictive value of 98%, a specificity of 45%, and a negative likelihood ratio of 0.09. In patients with a low or moderate pretest probability, the sensitivity, negative predictive value, and negative likelihood ratio were 97%, 99%, and 0.07, respectively. CONCLUSIONS: The MDA D-Dimer assay is the first latex agglutination assay with sufficient sensitivity to be clinically useful in the exclusion of venous thromboembolism. A negative result has the potential to be used as the sole test to exclude venous thromboembolism in patients with a low or moderate pretest probability of disease.

Factors Associated with the Use of Complementary and Alternative Medicine for Korean Patients with Rheumatoid Arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic autoimmune disease that is often painful and debilitating. Patients with RA are increasingly receiving complementary and alternative medicine (CAM). We aimed to identify the patient characteristics and disease-specific factors associated with Korean patients with RA who decide to start treatment with CAM. METHODS: Among the total 5371 patients with RA in the KORean Observational study Network for Arthritis (KORONA), 2175 patients who had no experience with CAM were included in our study. In our study, we assessed the frequency of new incident CAM use, its patterns, and the predictive factors of new CAM use. RESULTS: Of the 2175 patients, 229 patients (10.5%) newly started receiving CAM within a year of enrolling in the cohort. Of those who started treatment with CAM, 17.0% received only herbal medicine, 54.6% only acupuncture treatments (7.0% used a combination of both), and 21.4% "Other" (e.g., physical therapy and placental extract injections). Women (OR 1.89, 95% CI 1.13-3.14) and patients with depression (OR 3.52, 95% CI 1.65-7.50) were significantly more likely to be treated with CAM. Regarding household types, patients who lived in an extended family (OR 1.78, 95% CI 1.08-2.95) or as part of a couple (OR 1.55, 95% CI 1.07-2.24) were more likely to be treated with CAM than patients living in a nuclear family. CONCLUSION: Our study found, within a year, an incidence rate of 10.5% for new CAM use among patients with no previous experience with CAM. Sex, depression, and household type were significantly associated with new CAM use.

A comparative analysis of D-dimer assays in patients with clinically suspected pulmonary embolism.

To avoid angiography in patients with clinically suspected pulmonary embolism and non-diagnostic lung scan results, the use of D-dimer has been advocated. We assessed plasma samples of 151 consecutive patients with clinically suspected pulmonary embolism. Lung scan results were: normal (43), high probability (48) and non-diagnostic (60; angiography performed in 43; 12 pulmonary emboli). Reproducibility, cut-off values, specificity, and percentage of patients in whom angiography could be avoided (with sensitivity 100%) were determined for two latex and four ELISA assays. The latex methods (cut-off 500 micrograms/l) agreed with corresponding ELISA tests in 83% (15% normal latex, abnormal ELISA) and 81% (7% normal latex, abnormal ELISA). ELISA methods showed considerable within- (2-17%) and between-assay variation (12-26%). Cut-off values were 25 micrograms/l (Behring), 50 micrograms/l (Agen), 300 micrograms/l (Stago) and 550 micrograms/l (Organon). Specificity was 14-38%; in 4-15% of patients angiography could be avoided. We conclude that latex D-dimer assays appear not useful, whereas ELISA methods may be of limited value in the exclusion of pulmonary embolism.

Reliability of five rapid D-dimer assays compared to ELISA in the exclusion of deep venous thrombosis.

Studies measuring the fibrin degradation product D-Dimer (DD) using enzyme-linked immunosorbent assays (ELISA) in patients with venographically proven deep venous thrombosis (DVT) suggest that it is possible to exclude DVT when DD level is below a certain cut-off level. However, ELISA methods are time-consuming and not available in all laboratories. Different rapid latex-agglutination assays have been investigated, but their sensitivity is considerably lower. In the present study we compared the value of four novel latex DD tests (Tinaquant, Minutex, Ortho and SimpliRed) and one rapid ELISA (VIDAS) to a classical ELISA DD assay (Organon Mab Y18) in 132 patients suspected of DVT. The VIDAS, a new quantitative automated ELISA, had a sensitivity of 100% and a negative predictive value of 100% for both proximal and distal DVT at a cut-off level of 500 ng/ml. The Tinaquant assay, a new quantitative latex method, had a sensitivity of 99% and a negative predictive value of 93% for both proximal and distal DVT at a cut-off level of 500 ng/ml. For proximal DVT only, both assays had a sensitivity and negative predictive value of 100%. VIDAS and Tinaquant correlated well with ELISA (correlation of r = 0.96 and r = 0.98 respectively). Sensitivities of the semi-quantitative latex assays Minutex, Ortho and SimpliRed were considerably lower (77%, 51% and 61% respectively). These results suggest that VIDAS and Tinaquant may be used instead of ELISA DD in the exclusion of DVT. Tinaquant can be performed within 20 min and VIDAS within 35 min. Both assays might be used as a routine screening test and should be evaluated in large clinical management studies.

D-dimer test and diagnosis of deep vein thrombosis: a comparative study of 7 assays.

The current D-Dimer ELISA methods provide high sensitivity and negative predictive value for the diagnosis of deep vein thrombosis but these methods are not suitable for emergency or for individual determination. We have evaluated the performance of 3 newly available fast D-Dimer assays (Vidas D-Di, BioMérieux; Instant IA D-Di, Stago; Nycocard D-Dimer, Nycomed) in comparison with 3 classic ELISA methods (Stago, Organon, Behring) and a Latex agglutination technique (Stago). One-hundred-and-seventy-one patients suspected of presenting a first episode of deep vein thrombosis were investigated. A deep vein thrombosis was detected in 75 patients (43.8%) by ultrasonic duplex scanning of the lower limbs; in 11 of them the thrombi were distal and very limited in size (< 2 cm). We compared the performance of the tests by calculating their sensitivity, specificity, positive and negative predictive value for different cut-off levels and by calculating the area under ROC curves. The concordance of the different methods was evaluated by calculating the kappa coefficient. The performances of the 3 classic ELISA and of the Vidas D-Di were comparable and kappa coefficients indicated a good concordance between the results provided by these assays. Their sensitivity slightly declined for detection of the very small thrombi. Instant IA D-Di had a non-significantly lower sensitivity and negative predictive value than the 4 previous assays; however its performance was excellent for out-patients. As expected, the Latex assay had too low a sensitivity and negative predictive value to be recommended. In our hands, Nycocard D-Dimer also exhibited low sensitivity and negative predictive value, which were significantly improved when the plasma samples were tested by the manufacturer. Thus significant progress has been made, allowing clinical studies to be planned to compare the safety and cost-effectiveness of D-Dimer strategy to those of the conventional methods for the diagnosis of venous thrombosis.

Rapid immunodiagnosis of streptococci and enterococci in blood cultures.

We evaluated a procedure for rapid identification of blood culture isolates of pneumococci, enterococci and beta-haemolytic streptococci groups A, B, C, and G. Immunological tests were applied directly to blood culture medium and included a quellung reaction for pneumococci, and latex agglutination tests (LAT) for pneumococcal antigen and Lancefield antigens A, B, C, D and G. During a one-year trial period with approximately 12,000 blood culture sets (BacT/Alert, Organon-Teknika), 208 sets showed pure growth of gram-positive cocci in pairs or chains by direct microscopy. Overall, a correct diagnosis was noted for 103 (63.2%, 95% CI: 55.3-70.6%) of 163 sets yielding pneumococci, beta-haemolytic streptococci, or enterococci. A procedure excluding Lancefield antigens only A, B, and D was implemented during a one-year follow-up period. With this simplified procedure positive and negative predictive values, respectively, were 1.00 and 0.87 for pneumococci, 1.00 and 0.94 for beta-haemolytic streptococci group A, 0.60 and 1.00 for beta-haemolytic streptococci group B, and 0.91 and 0.88 for enterococci. We conclude that rapid identification of gram-positive cocci is feasible and may improve the information given to clinicians at the first notification of positive blood cultures.

Screening of blood donors for cytomegalovirus (CMV) antibodies: an evaluation of different tests.

The incidence of transfusion-associated cytomegalovirus (CMV) infections is related to the number of donors and the volume of blood. In immunosuppressed patients primary CMV infection is associated with a high morbidity and/or mortality. These infections can be prevented by the use of CMV negative blood products. A test for screening of CMV antibodies should have a high sensitivity and specificity and in addition be rapid and easily automated. In the present study the routine method in the laboratory, a CMV ELISA using a nuclear CMV antigen, was compared with Vironostika CMV anti-IgG MicroELISA, CMVSCAN, a latex agglutination test and a new ELISA from Organon Teknika, Vironostika CMV one-step MicroELISA. Sera from 419 blood donors were tested by all four tests. Discordant results were resolved by Western blot analysis using a glycine-extracted CMV antigen. The sensitivity was 100% for CMV ELISA and CMVSCAN and 99 and 96% for the CMV anti-IgG and CMV one-step tests respectively. The specificity was 100, 99, 94 and 100%, respectively. The ELISAs are suitable for screening of large numbers of serum samples and the CMV one-step test in particular was rapid and easy to perform although the sensitivity has to be increased. The latex agglutination test has the advantage of being extremely rapid.

The Karpas AIDS Cell Test compared with an enzyme-linked immunosorbent assay for detecting antibody to the human immunodeficiency viruses (HIV-I and HIV-2).

We have compared the Karpas AIDS Cell Test for antibodies to the human immunodeficiency viruses (HIV) with a commercial enzyme-linked immunosorbent assay (ELISA) (Organon Teknika) by testing serum samples from 324 intravenous drug abusers in Turin. The cell test was found to be more sensitive and as specific as the ELISA with the serum samples from the drug abusers. In Lisbon, 30 samples were tested on slides containing cells infected with HIV-1 and/or HIV-2. All 15 samples, which were positive for HIV-2 alone (in the HIV-2 Elavia test and by the Western blotting technique), were also positive in the Karpas AIDS test. In contrast, only one of the 15 samples (7%) gave a positive reading in the ELISA for HIV-1. Results of 30 samples tested in Turin and Lisbon by the Western blotting technique agreed closely with those obtained with the Karpas AIDS Cell Test. We were also able to show that the entire test can be performed at room temperature and completed within 1 hour. Moreover, the cell test requires minimal skill and simple equipment and is inexpensive. It also includes non-infected cells as a control and the specificity of positive samples may be verified with a bench microscope. Furthermore, this test which detects antibodies to both HIV-1 and HIV-2 allows rapid typing of the infecting strain.

Human plasma fibrinogen measurement derived from activated partial thromboplastin time clot formation.

Prothrombin time-derived measurement of fibrinogen (PTd) has already been described. Activated partial thromboplastin time-derived measurement of fibrinogen (aPTTd) has not yet been clearly defined. Using an MDA II coagulometer (Organon Teknika, Durham, North Carolina, USA), we have therefore compared fibrinogen levels determined with Clauss, PTd, and aPTTd assays and an enzyme immunoassay (EIA) in 172 samples. Of these, 47 were from pre-operative controls, 18 from patients with liver disease, 28 from patients with hyperfibrinogenaemia, 33 from patients treated with vitamin K antagonists, 22 from patients treated with unfractionated heparin and 24 from haemophilic patients. Within the normal range, interassay and intra-assay variations were comparable. For control samples, PTd, aPTTd and Clauss assays were well correlated, without any systematic error. EIA was also correlated but values were slightly higher (mean of difference = 0.24). Pathological samples showed an overestimation of fibrinogen when using PTd measurements in patients treated with vitamin K antagonists, as well as when using aPTTd measurements in patients presenting with factor VIII and factor IX deficiencies. These results indicate that, despite expected financial savings, aPTTd fibrinogen measurements should not be used without restriction. PTd and aPTTd fibrinogen determinations are provided without any additional cost. Their comparison with Clauss fibrinogen results may constitute a validation tool or have additional diagnostic utility (e.g. identifying polymerization abnormalities in case of dissimilar results).

The GC-MS detection and characterization of reticuline as a marker of opium use.

Reticuline (a precursor of opium alkaloids) was detected and characterised as its trimethylsilyl ethers, acetyl esters and methyl ethers by GC-EIMS and GC-CIMS in opium and the urine of opium users after hydrolysis by acid or beta-glucuronidase as coextractive of morphine. Because this compound cannot be detected in heroin and poppy seeds, it is suggested as a differentiating marker between opium and heroin use, opium and poppy seeds use, or opium and "pharmaceutical" codeine use in cases when opiate use has been confirmed by detection of morphine and codeine in the urine. As well as being a constituent of opium, reticuline in the urine of opium users may also result from the metabolic demethylation of the three other benzyltetrahydroisoquinoline opium alkaloids: codamine, laudanosine and laudanine.

The GC-MS detection and characterization of reticuline as a marker of opium use.

Reticuline (a precursor of opium alkaloids) was detected and characterised as its trimethylsilyl ethers, acetyl esters and methyl ethers by GC-EIMS and GC-CIMS in opium and the urine of opium users after hydrolysis by acid or beta-glucuronidase as coextractive of morphine. Because this compound cannot be detected in heroin and poppy seeds, it is suggested as a differentiating marker between opium and heroin use, opium and poppy seeds use, or opium and "pharmaceutical" codeine use in cases when opiate use has been confirmed by detection of morphine and codeine in the urine. As well as being a constituent of opium, reticuline in the urine of opium users may also result from the metabolic demethylation of the three other benzyltetrahydroisoquinoline opium alkaloids: codamine, laudanosine and laudanine.