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At least 991 records · Page 55Linked to original sources

Estimation of receiver-operating characteristic curves to determine accuracy of a competitive enzyme-linked immunosorbent assay for the serodiagnosis of Brucella infection in domestic water buffalo (Bubalus bubalis) and cattle.

OBJECTIVE: To estimate receiver-operating characteristic (ROC) curves for a competitive ELISA (c-ELISA) that is used in serodiagnosis of brucellosis in water buffalo and cattle, to determine the most appropriate positive cutoff value for the c-ELISA in confirmation of infection, and to evaluate species differences in c-ELISA function. SAMPLE POPULATION: Sera from 4 herds of cattle (n = 391) and 4 herds of water buffalo (381). PROCEDURE: Serum samples were evaluated for Brucella-specific antibodies by use of a c-ELISA. On the basis of previous serologic test results, iterative simulation modeling was used to classify animals as positive or negative for Brucella infection without the use of a gold standard. Accuracy of c-ELISA for diagnosis of infection was compared between cattle and water buffalo by comparison of areas under ROC curves. RESULTS: A positive cutoff value of 30% inhibition for c-ELISA yielded sensitivity and specificity estimates, respectively, of 83.9 and 92.6% for cattle and 91.4 and 95.4% for water buffalo. A positive cutoff value of 35% inhibition yielded sensitivity and specificity estimates, respectively, of 83.9 and 96.2% for cattle and 88.0 and 974% for water buffalo. Areas under ROC curves were 0.94 and 0.98 for cattle and water buffalo, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: ROC curves can be estimated by use of iterative simulation methods to determine optimal cutoff values for diagnostic tests with quantitative outcomes. A cutoff value of 35% inhibition for the c-ELISA was found to be most appropriate for confirmation of Brucella infection in cattle and water buffalo.

Animals↗

CNS stimulant controversies.

Controversies in the use of central nervous system stimulant medications in children with attention deficit hyperactivity disorder are discussed. Diagnostic issues, age of optimal use, side effects, effects on learning and ethical considerations are current issues. An animal model for the effects of chronic long-term high dose regimes is proposed.

Adolescent↗

[Assessment of two DNA extraction methods to amplify the pneumolysin gene (PLY) from blood culture samples of Streptococcus pneumoniae].

BACKGROUND: Streptococcus pneumoniae is a common etiologic agent of invasive respiratory infections among children under 5 years of age and older adults. Isolation rates of S. pneumoniae by traditional culture techniques are low. AIM: To study the sensitivity and specificity of two different DNA extraction methods to amplify the ply gene, applied to three different types of blood culture broths, experimentally inoculated with S. pneumoniae. MATERIAL AND METHODS: DNA was extracted from the cultures using an organic method or a technique that consists in dilution, washing with NaOH and concentration of the sample. This was followed by PCR amplification of a 355 pb fragment of the pneumolysin gene (ply). RESULTS: The organic DNA extraction method inhibited the PCR reaction at all concentrations studied (0.6 to 10(6) colony forming units/mL). Using the NaOH extraction, ply gene amplification was positive in all three blood culture broths, but only at concentrations of 10(3) colony forming units/mL, or higher. Using the same DNA extraction method, PCR was negative when the broths were inoculated with seven other related bacterial species, which results in a 100% specificity. CONCLUSIONS: Detection of S. pneumoniae by amplification of ply gene from blood cultures using the protocol of NaOH for DNA extraction is specific and provides results in a short lapse. However, the diagnostic sensitivity is not optimal, which limits its clinical use.

Bacterial Proteins↗

MR imaging artifacts. Challenges and solutions.

A wide variety of artifacts is routinely encountered on MR images. This article reviews the cause, appearance, diagnostic effect, and available remedies for the artifacts that are most frequently observed on MR images and are of greatest clinical significance. Combined with routine preventive maintenance of imaging equipment, consistent quality control, and appropriate selection of imaging parameters, awareness of the manifestations of these artifacts will allow image quality and diagnostic interpretation to be optimized.

Artifacts↗

Obstructive sleep apnea (OSA): a cephalometric analysis of severe and non-severe OSA patients. Part II: A predictive discriminant function analysis.

One hundred male obstructive sleep apnea (OSA) patients were classified into 2 groups on the basis of apnea-hypopnea index (AHI) as severe (AHI > or = 50) and non-severe (AHI < 50). A comprehensive cephalometric analysis of cervicocraniofacial skeletal and upper airway soft tissue morphology was performed in 51 non-severe and 49 severe OSA patients. In addition, a multivariate statistical method (principal component, analysis and predictive discriminant analysis) was performed to identify the components that could correctly differentiate the severe from the non-severe OSA patients. Eight principal components (PCs) of cervicocraniofacial skeletal morphology, 4 PCs of hyoid bone position and head posture, and 7 PCs of upper airway soft tissue morphology, together with the selected demographic variables, were deduced to formulate a linear canonical discriminant function. The equation of a 9-variable model was generated as follows: PDF score = 4.127 - 0.144 (Body Mass Index) - 0.376 (PC1.1) + 0.311 (PC1.4) + 0.214 (PC1.5) + 0.075 (PC 2.1) - 1.309 (PC2.3) + 0.708 (PC3.2) - 0.059 (PC3.3) + 0.609 (PC3.6). The cutoff score was -0.03899. The overall rate of correct classification was 83%. The results showed that Body Mass Index and 8 other PCs contributed significantly to the OSA severity. These analyses are proven to be a useful adjunctive diagnostic tool to select optimal treatment regimens for OSA patients with varying degrees of severity.

Aged↗

Maximizing opacification during excretory urography: effect of low-osmolarity contrast media.

Because of improved patient tolerance and decreased risks of idiosyncratic reaction, low-osmolarity contrast media are increasingly used for excretory urography. However, physiologic differences among patients may affect the optimal time for acquiring diagnostic radiographs during the pyelographic phase of the examination. A prospective, randomized, physician-blinded comparative study of 60 adult patients was undertaken to determine if the time to peak opacification of the pyelocaliceal systems differs with different doses of nonionic and ionic contrast media. Three doses of contrast media were used: a high dose (based on body weight) of a high-osmolarity ionic contrast medium, a high dose (based on body weight) of a low-osmolarity non-ionic contrast medium and a lower, fixed dose of a low-osmolarity nonionic contrast medium. The diagnostic quality of the radiographs did not differ statistically with the dose or the contrast medium. However, acquiring an additional radiograph during abdominal compression greatly increased the chance of obtaining at least one radiograph with maximal diagnostic information during the pyelographic phase. Despite potential differences among contrast media in the degree of pyelocaliceal opacification or distension and diuresis, it is not necessary to modify the timing of film acquisitions during excretory urography when lower doses of low-osmolarity agents are administered.

Adult↗

[Hirsutism, what can be done?].

Hirsutism is a relatively frequent condition in an ambulatory setting affecting about 4% of women. A rational clinical and biochemical diagnostic approach assures an optimal treatment directed at etiologic and pathogenetic factors. The diagnosis of hyperandrogenism is evaluated considering the pathophysiologic mechanisms responsible for excessive growth of hair. Ovarian and adrenal tumors are the most serious diseases that have to be excluded by clinical and biochemical tests. The other causes for hirsutism are treatable by a great variety of modalities, available drugs can inhibit pituitary gonadotropins, the hypothalamo-pituitary axis and the conversion of testosterone into biologically active substrate. Finally the binding of androgens to its receptor can be blocked. These possibilities for treatment and their indications for the different etiologies of hirsutism are discussed.

Adrenal Cortex Hormones↗

[Traumatic airway disruption in a child: a diagnostic challenge].

OBJECTIVE: To report a case of airway disruption in a child victim of blunt thoracic trauma due to falling off a sink. DESCRIPTION: Descriptive case report. A 34-month old boy victim of thoracic trauma was seen at the pediatric intensive care unit of a university hospital. Plain chest radiograph, thoracic computed tomography, bronchoscopy, thoracotomy, antibiotics, hemodynamic and respiratory support were performed. Plain chest radiograph, thoracic computed tomography and bronchoscopy were performed in order to arrive at a precise diagnosis of traumatic airway disruption associated with pulmonary contusion, pneumothorax, mediastinal and subcutaneous emphysema. The patient underwent thoracotomy for surgical repair of an almost complete disruption of the left main bronchus. Antibiotics and ventilatory support contributed to a favorable outcome without medium-term sequelae. COMMENTS: Children presenting with thoracic trauma must be investigated for uncommon, but potentially lethal injuries, such as tracheobronchial disruption, particularly in cases where there is strong clinical evidence. Diagnostic workup should be optimized with plain chest radiograph and thoracic computed tomography, while bronchoscopy will confirm the definitive diagnosis.

Bronchi↗

[Scientific ideas of I. M. Sechenov, and neurophysiological studies of system stress conditions in occupational healthcare].

Occupational healthcare is one of the priority directions of modern sciences of life. Its achievements are based upon scientific ideas of Sechenov, the first Russian explorer of brain bioelectric activity. The modern neurophysiologic methodology of formalized quantitative evaluation of homeostasis in the higher brain structures allows optimization of early etiological diagnostics and prevention of stress reactions of central nervous and cardiovascular systems of workers exposed to hazardous factors of industrial environment.

Adaptation, Physiological↗

Multislice computed tomography of the sternum: which image reconstruction do we need?

OBJECTIVE: To assess the diagnostic value and to optimize image reconstruction for multislice spiral computed tomography (MSCT) of the sternum. MATERIALS AND METHODS: Forty patients underwent MSCT of the sternum using a standardized examination protocol (4x1 mm or 4x2.5 mm collimation; 120 kV, 120 mAseff). Axial images with an effective slice thickness of 1.25 mm or 3 mm and an increment of 0.8 mm or 1 mm were reconstructed. Coronal and sagittal reformations with a slice thickness between 2 mm or 3 mm and 5 mm and a slice distance ranging from 1 mm to 4 mm (overlap 1 mm) were calculated. In all patients, additional plain film radiographs (n=9) or clinical follow-up data were available. Image quality was assessed visually using a five-point grading scale. RESULTS: In all patients, the correct diagnosis was established using multiplanar reformats (MPR) exclusively. Best image quality for MPR was achieved using a slice thickness of 3 mm and a slice distance of 2 mm. Images acquired with a 4x1 mm collimation proved superior to images reconstructed from data obtained with a 4x2.5 mm collimation. CONCLUSION: MPR from MSCT data are a valuable tool for the diagnosis of sternal pathologies. For best image quality the thinnest possible collimation should be chosen.

Diagnosis, Differential↗

[Embryo and fetal pathology in routine diagnostics: what has changed and what needs to be changed].

The Authors have focused on the most important feto-neonatal and placental diseases in order to develop modern diagnostic tools which can meet the needs of clinicians (obstetricians, gynecologists, and neonatologists) for the best possible management of both the mother and the newborn. Although far from being operational instructions, it should be intended as a programmatic document providing a guideline on the issues that have cropped up in eight years of work of the APEFA group, as well as during several residential and practical classes. First of all, a synopsis is provided of the main issues concerning placental diagnosis in the newborn, as well as in case of fetal loss. A reasoned review is then provided of the main diagnostic criteria in placental pathology, in the light of therapeutical measures toward the mother (monitoring of future pregnancies) and the newborn (management of newborns at risk or with infectious disease). Legal issues in case of fetal distress at the end of pregnancy, neonatal damage and peripartum death have also been discussed with particular attention. Early and late miscarriages have also been separately examined, as well as fetal deaths. For each of these categories, a critical analysis is presented of current issues, followed by some considerations on the development of diagnostic methods and technology, and a modern diagnostic process is then outlined. Reference tables are also provided for diagnostic, auxological parameters, as well as on essential procedures. Issues concerning legal abortions and terminations of pregnancies have also been considered, with particular reference to tests and supplemental genetic and ultrasound examinations, diagnostic questions about malformations and forensic medicine assessments that are often involved with these specific categories. Malformations, fetal distress and growth retardation, sudden fetal and neonatal death, as well as embryo-pathology are all briefly dealt with also with synoptic tables. Diagnostic criteria are thus optimized and specially aimed at solving "human reproduction pathology" issues.

Abortion, Induced↗

[Liver abscesses of the right hepatic lobe after cholecystectomy].

The authors discuss the results of the diagnosis and treatment of abscesses of the right hepatic lobe which were consequent upon ischemic necrosis; they were encountered after cholecystectomy in 0.15% of cases. Ultrasonography and angiography are the main diagnostic methods suggested. The optimal results of treatment were produces in combination of percutaneous drainage and puncture of the destruction cavities under control of ultrasonography and endovascular regional infusion therapy.

Aged↗

[Endoscopy or trial treatment of patients with dyspepsia?].

The predictive value of dyspeptic symptoms is low. Upper GI endoscopy is the diagnostic gold standard, giving optimal basis for adequate drug treatment and may have a positive influence on the prognosis of non ulcer dyspepsia. Accordingly, endoscopy tends to be recommended at an early stage of chronic dyspepsia. Age above 40 years, pains relieved by food or antacids, night pains, smoking and male sex enhances the probability of an organic disease and thus the need for endoscopy. Trial treatment is recommended if the waiting period for endoscopy exceeds two weeks. Patients previously endoscoped may often be treated in accordance with earlier diagnosis and drug experience when relapsing. Drug choice when there is no firm diagnosis, should be determined by the symptom pattern. Two weeks of treatment failure necessitates endoscopy. Individual trial packages containing both the active drug and placebo could improve decision making in clinical practice.

Adult↗

[Planning the pathological departments of modern large clinics].

With the increasing importance of pathomorphological research as an integral element of optimization of therapeutic-diagnostic service of a modern hospital, it is important to improve the structure and technical basis of the pathology departments. The experience of pathological service and the analysis of projects of pathology departments included in the current type projects of clinical and other hospitals reveal some unsatisfactory features in architectural planning and in medico-technological aspects. This handicaps the improvement of the pathological service as an element of medical service and the subject of teaching. Recommendations on these problems are presented.

Hospital Bed Capacity, 500 and over↗

[Diagnosis in urinary tract infections].

For a rational diagnostic work-up of urinary tract infections (UTI), a detailed history and a standardised examination of smear material, prostatic fluid and urine are essential. Examination of the urine is simple, with test strips, microscopic examination of the sediment and determination of the bacterial count by the dipstick procedure having proved their worth in practice. Isolation and identification of pathogens and the preparation of an antibiogram require special knowledge of microbiological techniques. Accurate evaluation of the urine and its constituents requires a knowledge of how the urine has been collected; we recommend spontaneously passed urine in men and young children, and catheter urine in women. Acute complicated and chronic recurrent UTIs require radiological studies and sonography. Occasionally, nuclear-medical investigations and angiography or CT may be necessary for detailed classification. In cases of obstruction of the lower UT or neurogenic problems with urinary bladder, urodynamic investigation and endoscopy must be performed. This stepwise diagnostic evaluation allows both optimal classification of the UTI and a saving in costs.

Bacterial Infections↗

The effect of sennosides on colonic mucosal histology and bowel preparation.

INTRODUCTION: A single high dose of sennosides is often used to optimize bowel preparation for diagnostic procedures. From previous studies it is suspected that sennosides in such a dose cause acute damage to the colonic mucosa. This study was designed to determine any effects of sennosides on histology of colonic mucosa and on bowel preparation. RESULTS: In a prospective study 171 patients were randomized for bowel preparation. 84 patients received 1 ml/kg (maximal 75 ml) of a syrup containing 2.0 mg/ml sennoside A and B and 3-5 l of a lavage solution (Sen), 87 patients only received 3-5 l lavage solution (NSen). All patients completed a questionnaire on which patient tolerance was scored. Another questionnaire was completed by the endoscopist, recording quality of the preparation. From the 40 patients with a normal colon (19 Sen, 21 NSen) a biopsy was taken from the sigmoid colon and analyzed for morphological abnormalities. No difference could be demonstrated in tolerance or quality of bowel preparation between the two groups. A marked increase of mononuclear infiltrate in the lamina propria was observed in Sen compared to NSen: in 10/19 vs. 2/21 patients respectively, p < 0.0005. CONCLUSION: As these microscopic effects could hamper the interpretation of colonic biopsies, bowel preparation without sennosides is to be recommended.

Adolescent↗

[Results of radiotherapy in the year of the Röntgen centenary].

In 1996, the three leading radiation oncology periodicals (Int. J. Radiat. Oncol. Biol. Phys.--USA, Radiother. Oncol.--Europe, and Strahlenther. Onkol.--Germany) published 681 papers. Among the different topics, the clinical subjects accounted for almost half (46%) of the total number of publications, followed by radiation physics/techniques (18%) and radiation biology (17%). The 13% of editorials/review articles reflects a considerable endeavor towards integration; the contribution of papers relating to professional organization amounted to 2%. The fact that 1996 was the centennial year of the discovery of the Röntgen rays explains the reasonable proportion (4%) of historical reviews. Within the special topics, prostatic cancer and breast cancer were the two most frequent issues. Dose escalation was the most important tool applied to improve the results of the radiation therapy of tumors with unfavorable prognostic signs or radioresistance. The increase in the applied dose was made possible by a decrease in the planning target volume (PTV), 3D forward and inverse radiation treatment planning, a combination of tomographic (CT/MRI/US) diagnostic methods (image registration/fusion), optimizing algorithms, computer-controlled delivery of radiation dose and electronic portal imaging with in vivo dosimetry. In contrast, the trends in the radiotherapy of tumors with favorable long-term survival (e.g. Hodgkin's disease and seminoma) include a decreased dose and PTV reduction to diminish the late, radiation-related morbidity. Fractionation has remained the only tool of radiobiology routinely used in the everyday clinical practice. A comparison of the results and achievements in the special fields reveals that radiation physics/techniques clearly outstrip clinical subjects and especially radiation biology, as they allow direct and instant exploitation of the advantages offered by computers. It is highly probable, however, that, subsequent to a wider use of computers in clinical subjects and radiation biology, this situation will change.

Germany↗