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X-rays: laying the foundation of modern radiology, 1896-1930.

The authors describe the initial impact and far-reaching consequences of the discovery of x-rays in 1895. Roentgen was quick to realise the importance of this mysterious new kind of ray he had discovered. As early as 1896 x-rays were already being used in surgery and medicine, replacing Bell's telephonic needle probe, which could only detect metallic objects by sound and was therefore limited to the location of objects such as bullets for removel. As x-ray diagnosis became more accurate, radiological techniques were gradually improved over the years and progressed from examination of the skeleton to imaging complex internal organs. The x-ray became vital in the detection of tuberculosis, for which it is still used today. Through the use of opaque substances such as barium sulfate it became possible to visualise the digestive tract and later advances in photographic techniques made visible the brain and almost all parts of the body. Meanwhile the dangers of radiation were recognized and after 1930 safety measures were introduced to protect radiologists and patients against overexposure. In the hundred years since its discovery the ever-widening scope of radiology has made it a fundamental resource in medical diagnosis and treatment.

History, 19th Century↗

[Preparation of the microarray for detecting hepatitis D virus].

OBJECTIVE: To prepare the microarray for detection of hepatitis D virus (HDV). METHOD: Several pairs of specific PCR primers were designed according to the conserved region of HDV genome. The DNA microarray were prepared by blotting the PCR products onto the surface of glass slides with the use of robotics, and restriction display PCR (RD-PCR) was employed to label the samples. RESULT: Sequences analysis showed that the products of PCR amplification were the specific gene fragments of HDV. Hybridization signals on the gene chip demonstrated good specificity and sensitivity of the microarray for HDV detection. CONCLUSION: Microarray-based clinical HDV detection can be sensitive and effective.

Base Sequence↗

The interaction of eye movements and retinal signals during the perception of 3-D motion direction.

When an object is tracked with the eyes, veridical perception of the motion of that object and other objects requires the brain to take account of and compensate for the eye movement. Here, I explore the effects of version and vergence eye movements on three-dimensional (3-D) motion perception. After demonstrating that eye movement compensation can be poor for detecting small objects moving in depth, I develop two models for how eye movement and visual signals may interact during the perception of 3-D motion direction. The first model assumes that the visual system is aiming to form an explicit representation of 3-D motion. From the results of a second experiment, on 3-D motion direction judgements, I show that this model could only hold with almost perfect 3-D motion compensation, contradicting the results from the first experiment. A second model assumes a much simpler strategy for estimating 3-D motion direction, based on recent experimental work. It predicts that compensation for vergence is not required because the Z-component of 3-D motion is not needed for direction judgements, consistent with the experimental results. This suggests that, for 3-D motion direction discrimination and angle judgements, extraretinal signals from vergence are not used.

Adaptation, Physiological↗

Diagnostic value of anti-F-actin antibodies in a French multicenter study.

According to international criteria, autoimmune hepatitis (AIH) type 1 is characterized by the presence of antinuclear or anti-smooth muscle antibodies (SMA) with F-actin specificity. SMA have been found in 85% of AIH patients, but are not specific to this disease, and anti-F-actin specificity is not always verified when SMA are detected. The objective of this study was to determine the diagnostic value of anti-F-actin antibodies in a large population. A multicenter study involving 12 clinical centers was performed. Patients were selected on the basis of the presence of F-actin SMA detected by indirect immunofluorescence (IIF) on rat liver-kidney-stomach sections and was confirmed by IIF on Hep2 cells treated with colchicine, or F-actin dot-blot. The clinical status of patients was determined from their medical records. One hundred sixty-eight patients were included: 76% women, 24% men; mean age of 45 years (range, 2-88 years), with a bimodal age distribution. Sixty percent had AIH type 1, and 40% had another disease. In the group of women younger than 25 years, 90% had AIH type 1. Other pathologies associated with antiactin were other liver diseases (19%), including viral hepatitis C (7%), and non-liver diseases (21%), including connective tissue diseases (12%). Antibody titers were higher in AIH than in other diseases. Antiactin antibodies are of major diagnostic value in AIH, especially in young women; they may be found in other disease settings, but mostly at low levels.

Actins↗

The right hemisphere as an anomaly detector: evidence from visual perception.

V. S. Ramachandran (1998) has suggested that the right hemisphere, which tends to be specialized for the analysis of global-level information, serves as an anomaly detector. Its role is to judge whether a given percept is possible and whether there are elements of that percept that seem incongruent with the other elements. In contrast, the left hemisphere tends to create a "story" to make sense of the incongruities. In the current study, pictures of possible or impossible objects were displayed for brief exposure durations to either the left visual field/right hemisphere or to the right visual field/left hemisphere). The results provide tentative support for the work of Ramachandran. In male participants, the right hemisphere was superior to the left in detecting impossible objects.

Brain↗

Electrodiagnostic methods for neurogenic dysphagia.

OBJECTIVE: Swallowing mechanisms and neurogenic dysphagia have not been systematically studied by the EMG technique. It is desirable to evaluate neurogenic dysphagia for diagnostic and possibly for therapeutic purposes using electrophysiological methods. METHODS: The following methods were described: mechanical upward/downward movements of the larynx were detected using a piezoelectric sensor, while submental integrated EMG activity was recorded during dry and wet swallowing. The EMG activity of cricopharyngeal muscle of the upper oesophageal sphincter was also recorded in some normal subjects and patients. Piecemeal deglutition and the dysphagia limit were determined in all patients to detect dysphagia objectively. In this study 75 normal subjects and 177 neurological patients with various degrees of dysphagia were investigated. RESULTS: Voluntarily triggered oropharyngeal swallowing was commonly pathological in the majority of patients, with or without overt dysphagia. The dysphagia limit appeared to be an objective measure of the degree of dysphagia in more than 90% of patients. Pathophysiological mechanisms were different in at least three groups of patients with neurogenic dysphagia. In the group of patients with muscular disorders, laryngeal elevators were involved while the CP-sphincter was intact. The second group included patients with the clinical signs of corticobulbar fibre involvement such as amyotrophic lateral sclerosis and pseudobulbar palsy. In these patients, there was incoordination between paretic laryngeal elevators and hyperreflexic CP-sphincter. In the third group (patients with Parkinson's disease), the swallowing reflex was delayed and prolonged. CONCLUSIONS: EMG methods described in the present study are very useful for the diagnosis of neurogenic dysphagia, objectively and quickly. They are important to understand the physiological mechanisms for deglutition and its disorders.

Adolescent↗

Rapid prenatal diagnosis of common trisomies: discordant results between QF-PCR analysis and karyotype analysis on long-term culture for a case of trisomy 18 detected in CVS.

OBJECTIVES: QF-PCR analysis can be used as a rapid test to diagnose primary trisomy in prenatal samples. Mosaicism in CVS detected by QF-PCR has previously been reported; however, no case has so far been reported in which the QF-PCR result was completely discrepant to that of the karyotype analysis from a long-term culture. METHODS: A CVS, referred because of a high serum screening risk of 1:10 for Down Syndrome and 1:110 for Edwards Syndrome, was tested by QF-PCR analysis and chromosome analysis of cultured cells. Subsequent analyses were carried out on a follow-up amniotic fluid sample and foetal tissue samples. RESULTS: Conflicting results were obtained between QF-PCR analysis on two independent fronds from the chorionic villi and chromosome analysis on cultured CVS. Cytogenetic and molecular analysis on a subsequent amniotic fluid sample indicated trisomy 18 with no evidence of mosaicism. Analysis of follow-up tissue confirmed trisomy in a foetal skin sample and mosaicism for trisomy 18 in four placental sites tested. CONCLUSION: We report here an apparently normal CVS QF-PCR result that was completely discrepant with the trisomy 18 positive karyotype result on long-term culture. This has important implications regarding our current testing protocol.

Adult↗

Nonpalpable mammographically occult invasive breast cancers detected by MRI.

OBJECTIVE: The purpose of this study was to determine the MRI findings and histology of clinically and mammographically occult invasive breast cancers detected by MRI. MATERIALS AND METHODS: A retrospective review was undertaken of 1,336 breast MRI examinations performed during a 2-year period. Among these, 68 nonpalpable mammographically occult invasive cancers were identified in 57 women with a median age of 50 years (range, 30-72 years). MRI findings were classified according to the breast MRI lexicon. Medical records were reviewed to determine the histology. RESULTS: Indications for performing MRI were extent of disease assessment in 72% (41/57), high-risk screening in 25% (14/57), and problem solving in 3% (2/57). MRI lesion types in these 68 invasive cancers were nonmass in 57% (39/68) and mass in 43% (29/68). Kinetics were plateau in 59% (40/68), washout in 38% (26/68), and persistent in 3% (2/68). Histology was invasive ductal cancer in 65% (44/68), mixed invasive ductal and lobular cancer in 19% (13/68), and invasive lobular cancer in 16% (11/68). The cancer stage was I in 61% (34/56), II in 32% (18/56), and more advanced in 7% (4/56). Sixty-three percent (43/68) of lesions were minimal cancers, defined as invasive cancers measuring under 1 cm. CONCLUSION: In this study of mammographically and clinically occult cancers detected by MRI, 57% (39/68) of invasive breast cancers were evident as nonmass enhancement, and 63% were minimal breast cancers.

Adult↗

Outcome of 17 patients with portal venous gas detected by CT.

OBJECTIVE: Portal venous gas has historically been associated with a poor prognosis. The clinical outcomes of 17 patients with portal venous gas detected by CT were reviewed. CONCLUSION: Portal venous gas seen on CT was associated with a 71% survival rate. Patients with a history of vascular surgery or bowel obstruction may have a higher mortality, and careful clinical evaluation is mandatory in this patient population.

Adult↗

Airport and superficial femoral artery obstruction due to a wandering coronary stent: the possibility of airport detection of modern implant metals.

In the treatment of coronary artery disease, peripheral loss of a coronary stent is an unusual complication. We present the case of a patient who suggested that his right leg claudication was caused by a slipped coronary stent 2 years previously. The patient was convinced about this unusual finding based on an airport security check. Examination proved him to be right. However, the ability to detect an object using eddy currents is dependent on the object's permeability and its conductivity. Ferrous (iron) content is not the critical factor. Modern implant materials and processing techniques result in implants that are difficult to magnetize i.e. their permeability is very low. In addition their conductivity is very low. This enables modern implants to escape detection at airports. For this reason the event at the airport, as described by our patient, is considered coincidental.

Angiography↗

Specific imaging of dialysis-related amyloid deposits using 131I-beta-2-microglobulin.

Dialysis-related amyloidosis (DRA), characterized by its association with beta 2-microglobulin (beta 2m), has become a major concern in long-term hemodialysis patients. Hitherto the diagnosis was based on histological examinations of tissue obtained by biopsy or during surgery. In this preliminary study a new noninvasive diagnostic method was developed using the affinity of beta 2m for its derived fibrils. 3 patients on long-term hemodialysis for 10-16 years with biopsy-proven DRA and 1 patient on chronic hemodialysis for only 6 months were examined after intravenous injection of 131I-labelled beta 2m. Specific local accumulation of radioactivity was noted in the DRA patients after 48 h, persisting for further 96 h and corresponding to clinically or radiologically evident sites of amyloid deposition and to several other hitherto unsuspected sites. Examination of an excised amyloid tumor subsequent to in vivo labelling confirmed a highly specific accumulation of radioactivity in the amyloid tissue but not in control tissue. In the patient on chronic hemodialysis for only 6 months, no specific local accumulation was detected even after 1 week. These findings provide in vivo evidence in man that a specific uptake of circulating amyloid precursor molecules into deposits occurs and that this uptake may be used to radiolabel even small tissue infiltrates of amyloid. This method therefore may not only allow an objective, noninvasive detection of DRA but may also be used to obtain new pathophysiologic insights into amyloid formation in man, as well as permitting the evaluation of preventive therapeutic strategies in prospective studies on new patients.

Amyloidosis↗

Efficacy of the Endo-pap sampler in detecting endometrial lesions.

OBJECTIVE: To determine the efficacy of the Endo-pap sampler, a device used to collect endometrial tissue fragments for cytologic examination, in detecting endometrial lesions. STUDY DESIGN: Reports from 1,983 Endo-pap smears collected from 1,248 outpatients over a 44-month period were retrospectively examined in conjunction with corresponding biopsy or hysterectomy reports. Endo-pap smears, histologic sections and clinical information were reviewed in cases originally reported as abnormal. RESULTS: Endometrial abnormalities were reported in 29 Endo-pap smears (1.5%). Among 21 reported as atypical, follow-up was normal in 19 but revealed hyperplasia in 1 and hyperplasia with a focus of carcinoma in 1 on histologic examination. Three were interpreted as malignant and one as suspicious; all had adenocarcinoma at endometrial biopsy. Endometrial abnormalities were reported in 19 of 220 patients who underwent endometrial biopsy following a previous Endo-pap smear reported as negative for malignancy. Their diagnoses included endometrial polyps (14), hyperplasia without atypia (3), atypical hyperplasia (1) and endometrial adenocarcinoma (1) three years after a negative Endo-pap smear. CONCLUSION: Although the sensitivity and specificity for malignancy were 100%, the overall sensitivity for any pathologic lesion was only 28%. We recommend proceeding directly to endometrial biopsy for a conclusive diagnosis in symptomatic patients.

Endometrial Neoplasms↗

Why do family physicians fail to detect renal impairment?

OBJECTIVE: To investigate why many patients with renal impairment (30.7%) were not recognized by their family physicians despite an earlier educational intervention on detecting renal impairment; and to determine whether certain factors related to physicians, patients, or the intervention itself were associated with whether renal impairment was detected. DESIGN: Qualitative approach using grounded theory. SETTING: A Health Service Organization in Ottawa, Ont. PARTICIPANTS: A purposeful sample of six family physicians. METHODS: In semistructured interviews, participants were asked to describe the workup ordered and their decision-making processes for patients in whom they had recently detected renal impairment. They were also asked to evaluate the six components of an educational intervention designed to help them to detect renal impairment. Finally, one patient's chart was reviewed (a chart containing a laboratory report noting an abnormal result for kidney function and having no indication that renal impairment had been recognized) to identify reasons for lack of detection. RESULTS: Most physicians did not investigate every patient with renal impairment (glomerular filtration rate of < 78 mL/min) in the same way because they took individual patient factors into consideration. Reasons for not detecting renal impairment were "managed differently" or "missed," with the former being the most common. The educational intervention physicians remembered most often was chart rounds, and these were viewed as helpful. "Missed" cases were more often deliberately managed differently than unintentionally not detected. CONCLUSION: Physicians used various approaches to detect and manage renal impairment despite interventions that recommended a consistent procedure.

Adult↗

Monoclonal antibodies for the direct detection of influenza-A virus by ELISA in clinical specimens from patients with respiratory infections.

BACKGROUND: Monoclonal antibody technology provides antibody reagents of known specificity, high titres and unlimited availability, that form ideal reference antibodies for use in specific viral antigen-detection methods. OBJECTIVES: To produce mouse monoclonal antibodies against antigenic sites of influenza-A virus, and evaluate their use as diagnostic reagents in a sandwich ELISA. STUDY DESIGN: (1) Production and characterization of monoclonal antibodies against influenza-A virus; (2) application of these antibodies in an ELISA method for direct antigen detection; and (3) evaluation of the ELISA as routine procedure. RESULTS: Four monoclonal antibodies (A1-A4) from mice immunized intranasally with influenza-A virus were selected according to their specific reactivity with either nucleoprotein or matrix protein antigens as demonstrated by Western blot analysis. These antibodies lacked haemagglutination inhibition and neutralization properties and recognized both H1N1 and H3N2 strains of influenza-A virus equally. A sandwich ELISA using unlabelled antibodies for antigen capture and biotin-labelled antibodies for antigen detection was used to analyse nasopharyngeal secretions or nasal swabs from culture-confirmed influenza-A-infected patients and comparable specimens from patients with other viral respiratory infections. Only influenza-A virus (strains H1N1 and H3N2) could be detected in samples from patients with known influenza-A and influenza-B infections, and also after re-isolation of such viruses in conventional cultures of MDCK cells or embryonated hens' eggs. The antigen-detection assay showed a diagnostic sensitivity of 100% and a specificity of 98.3% compared with conventional culture methods. CONCLUSION: The reported ELISA appears to be a rapid and inexpensive method for diagnosis and epidemiological studies of influenza-A infections.

Journal Article↗

An evaluation of rapid methods for detecting Escherichia coli O157 on beef carcasses.

Numbers of Escherichia coli O157 in food may be low and sensitive techniques are therefore needed for its detection. The objectives of this study were to use carcass meat samples artificially inoculated with various strains of E. coli O157 to compare the sensitivity of enrichment in three different media and to compare immunomagnetic separation followed by culture of magnetic beads to cefixime tellurite sorbitol MacConkey agar with three immunoassays for the detection of E. coli O157 in the enrichment cultures. Duplicate 250, 25 and 2-3 CFU of each of 16 strains of E. coli O157 added to 25-g samples of beef carcass meat were used to compare the sensitivity of (1) enrichment in supplemented tryptone soya broth (sTSB), Reveal 8-h and Reveal 20-h media, and (2) immunomagnetic separation and culture to cefixime tellurite sorbitol MacConkey agar (IMS/CT-SMAC) with Reveal, VIP and STAT immunoassays for detecting the organism. An initial inoculum of 250 CFU/25 g meat was detected in all 32 samples by IMS/CT-SMAC performed on all enrichment media and by Reveal performed on Reveal 8-h and Reveal 20-h media, but in only 30, 19 and 9 samples by Reveal, VIP and STAT, respectively, performed on sTSB medium. An initial inoculum of 25 CFU/25 g meat was detected in 28, 32 and 30 of 32 samples by IMS/CT-SMAC performed on sTSB, Reveal 8-h and Reveal 20-h media, respectively, and in 32 and 30 samples by Reveal performed on Reveal 8-h and Reveal 20-h media, but in only 22, 11 and 2 samples by Reveal, VIP and STAT, respectively, performed on sTSB medium. An initial inoculum of 2-3 CFU/25 g meat was detected in 25, 31 and 28 of 32 samples by IMS/CT-SMAC performed on sTSB, Reveal 8-h and Reveal 20-h media, respectively, and in 25 and 23 samples by Reveal performed on Reveal 8-h and Reveal 20-h media, but in only 14, 1 and 0 samples by Reveal, VIP and STAT, respectively, performed on sTSB medium.

Animals↗

Effective treatment of hormonally-unresponsive metastatic carcinoma of the prostate with adriamycin and cyclophosphamide: methods of documenting tumor response and progression.

Combination chemotherapy with Adriamycin and cyclophosphamide was administered to 22 men with progressive tumor following hormonal treatment for metastatic carcinoma of the prostate. Objective partial response was documented in 7 patients (32%); an additional four (18%) had stable disease for a minimum of four months, and 11 (50%) were non-responders. Patients with partial response had a median survival of 14 months and lived significantly longer than those with no response (median five months); survival of men with stable disease approximated that of partial responders. Serial utilization of multiple staging procedures during chemotherapy demonstrated that although no single test allowed identification of all patients with objective tumor response or progression, improvement in median of five parameters could be documented in responding patients. In patients adequately studied at the time of disease progression, deterioration in a median of six tests was found. Serum acid phosphatase radionuclide bone scan, and plasma carcinoembryonic antigen were the most sensitive procedures which detected both objective tumor response and progression. Toxicity of chemotherapy was acceptable except in patients with prior radiation therapy. Administration of Adriamycin and cyclophosphamide was associated with clinical benefit in half of our patients with hormone-resistant prostatic cancer. Tumor response and progression can best be objectively assessed if several staging procedures are serially employed during treatment.

Aged↗

Effects of energy drink ingestion on alcohol intoxication.

BACKGROUND: Well-known reports suggest that the use of energy drinks might reduce the intensity of the depressant effects of alcohol. However, there is little scientific evidence to support this hypothesis. OBJECTIVE AND METHODS: The present study aimed at evaluating the effects of the simultaneous ingestion of an alcohol (vodka(37.5%v/v)) and an energy drink (Red Bull-3.57 mL/kg), compared with those presented after the ingestion of an alcohol or an energy drink alone. Twenty-six young healthy volunteers were randomly assigned to 2 groups that received 0.6 or 1.0 g/kg alcohol, respectively. They all completed 3 experimental sessions in random order, 7 days apart: alcohol alone, energy drink alone, or alcohol plus energy drink. We evaluated the volunteers' breath alcohol concentration, subjective sensations of intoxication, objective effects on their motor coordination, and visual reaction time. RESULTS: When compared with the ingestion of alcohol alone, the ingestion of alcohol plus energy drink significantly reduced subjects' perception of headache, weakness, dry mouth, and impairment of motor coordination. However, the ingestion of the energy drink did not significantly reduce the deficits caused by alcohol on objective motor coordination and visual reaction time. The ingestion of the energy drink did not alter the breath alcohol concentration in either group. CONCLUSIONS: Even though the subjective perceptions of some symptoms of alcohol intoxication were less intense after the combined ingestion of the alcohol plus energy drink, these effects were not detected in objective measures of motor coordination and visual reaction time, as well as on the breath alcohol concentration.

Adult↗