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PubMed1996

Lidocaine and prilocaine with vasoconstrictors as cause for cardiovascular reactions. A pulse oximetric study. Preliminary report.

MATERIALS AND METHODS: Cardiovascular effects of two local anesthetic agent solutions containing 2% lidocaine with 1:80,000 epinephrine (LE) and 3% prilocaine with 0.54 microgram/ml felypressine (PF) used separately and in combination were observed. We made 38 separate monitoring sessions (30 minutes each) with healthy voluntary dental students. Participants were monitored with Cardiocap multiparameter physiological monitor. The monitored values were heart rate, systolic and diastolic blood pressure, SaO2 and peripheral blood flow. Values were registered into computer memory for further analysis. Group 1 received 7.2 ml of PF to the buccal sulcus just distal of the second upper right molar and 7.2 ml of LE to the left buccal sulcus ten minutes later. Group 2 had the same injection positions but they received 3.6 ml of PF to both sides of maxilla and then, ten minutes later, 3.6 ml of LE to each side. RESULTS: There were no radical changes in systolic or diastolic blood pressure. The blood oxygen saturation values were constant and the displayed SaO2 values were between 96-98% during the measurement period. Mean heart rate decreased about 10 beats/min after PF injection and increased about 10 beats/min after injection of LE in both groups. The peripheral blood flow (pbf) was the most sensitive parameter in our measurements. In general, pbf diminished in the period preceding the injection. It showed lowest values during the injection phases in both groups. CONCLUSIONS: Despite large doses of local anesthetics SaO2, systolic and diastolic blood pressure showed no clinically important changes, which suggests that local anesthetics have only a minimal effect on parameters mentioned above. This means that if the effect of one local anesthesia preparate (PF) is not sufficient, it is possible to safely reinforce the anesthesia with another substance (LE) in young healthy patients. Additionally, heart rate and pbf demonstrated quite clearly the symphatetic stimulation effect of the stress of injection and the stimulating action of epinephrine was seen clearly in heart rate values in both groups.

Adult↗
PubMed1990

Visualization of dynamic subcutaneous vasomotor response by computer-assisted thermography.

Infrared thermography is a noninvasive and nonionizing imaging modality which detects thermally significant subcutaneous blood vessels as linear heat patterns projected onto the skin surface. In clinical thermography, pseudo-colors are typically used to represent isothermal regions. However, pseudo-colors destroy the connectivity of vascular patterns since the intravenous temperature of a subcutaneous blood vessel varies along its length. This representation also confounds estimates of vessel boundary location since boundary information is rendered by temperature gradients, and not by isotherms. This paper describes two computer-assisted methodologies for the visualization of peripheral subcutaneous vasomotor events. The first approach, which utilizes a three-stage segmentation strategy based on edge detection, can visualize temperature differences of approximately 3.5 degrees C between the subcutaneous vessel boundaries and surrounding tissue. The second approach requires user interaction with an adaptive filtering algorithm that selectively enhances vascular patterns in the thermogram while decreasing background noise artifacts. The user interactively selects decision thresholds used by the algorithm to develop symbolic, axiomatic models of homogeneous and bimodal local contrast regions. The result of this trained filter is then employed in a technique called digital subtraction thermographic venography for the extraction of subcutaneous venous patterns. This second approach shows less ambiguity and higher sensitivity than the edge detection approach in resolving subtle temperature differences of approximately 1.2 degrees C between the vessel and surrounding tissue. Computer-processed frames from both of these approaches are used for the dynamic visualization of normal and pathological vasomotor responses to thermal challenges, thereby providing diagnostic visual cues which are unavailable in the original thermograms.

Algorithms↗
PubMed2000

Clinical and radiological characteristics of lung disease in inflammatory bowel disease.

The pulmonary associations of inflammatory bowel disease (IBD) are poorly characterized. The clinical, physiological and high-resolution computed tomographic thorax characteristics of the lung disease in patients with IBD presenting with respiratory symptoms are described. Detailed clinical information was obtained and standard pulmonary physiological tests and thorax high-resolution computed tomography performed on 14 patients with ulcerative colitis (UC) and three with Crohn's disease (CD), 10 male, aged 38-83 yrs. Respiratory symptoms had been present for 2-50 yrs and extraintestinal manifestations were present in three (17.6%). Normal pulmonary physiology (six patients) was associated with the high resolution computed tomographic changes of bronchiectasis, mosaic perfusion and air trapping suggestive of obliterative bronchiolitis and a pattern of centrilobular nodules and branching linear opacities ("tree in bud" appearance) suggestive of either cellular bronchiolitis or bronchiolectasis with mucoid secretions. Bronchiectasis was found in 13 patients (11 UC, 2 CD), 11 had air trapping and five had a "tree in bud" appearance on computed tomography. One patient had a predominantly peripheral reticular pattern at the lung bases similar to that found in cryptogenic fibrosing alveolitis and one patient had a mixed reticular and ground-glass pattern in the midzones with a patchy distribution in the central and peripheral portions of the lungs with air trapping. Eleven patients (three with alveolitis) exhibited a clinical and/or physiological response to steroids. Pulmonary abnormalities in ulcerative colitis and Crohn's disease can present years after the onset of the bowel disease and can affect any part of the lungs. Early recognition is important as they can be strikingly steroid-responsive.

Adult↗
PubMed2000

Cartilaginous airway wall dimensions and airway resistance in cystic fibrosis lungs.

It is not clear how airway pathology relates to the severity of airflow obstruction and increased bronchial responsiveness in cystic fibrosis (CF) patients. The aim of this study was to measure the airway dimensions of CF patients and to estimate the importance of these dimensions to airway resistance using a computational model. Airway dimensions were measured in lungs obtained from CF patients who had undergone lung transplantation (n=12), lobectomy (n=1), or autopsy (n=4). These dimensions were compared to those of airways from lobectomy specimens from 72 patients with various degrees of chronic obstructive pulmonary disease (COPD). The airway dimensions of the CF and COPD patients were introduced into a computational model to study their effect on airway resistance. The inner wall and smooth muscle areas of peripheral CF airways were increased 3.3- and 4.3-fold respectively compared to those of COPD airways. The epithelium was 53% greater in height in peripheral CF airways. The sensitivity and maximal plateau resistance of the computed dose/response curves were substantially increased in the CF patients compared to COPD patients. The changes in airway dimensions of cystic fibrosis patients probably contribute to the severe airflow obstruction, and to increased bronchial responsiveness, in these patients.

Adolescent↗
PubMed2004

A new computed-assisted technique for experimental sciatic nerve function analysis.

BACKGROUND: Peripheral nerve injury is a well-known experimental tool to evaluate the effect of various neurotrophic substances. Besides histological and electrophysiological techniques, nerve functional status has been assessed by means of the sciatic function index (SFI) and the static sciatic index (SSI). However, these techniques are still based on a complex and old-fashioned apparatus requiring a relatively long time of execution. This study aimed to assess a novel, rapid, computerized method for assessment of SSI in a rat model of sciatic nerve injury. MATERIAL/METHODS: Fourteen rats were used in this study. The left sciatic nerve was exposed and compressed for 2 minutes with an aneurysm clip. Functional evaluation was performed by analysing the footprints of standing rats, comparing the injured to the uninjured limb with the static sciatic index (SSI). For this purpose the rats were placed on a digital scanner and the resulting images were acquired on a personal computer. Analysis was carried out every day after surgery for 21 consecutive days. RESULTS: Two-minute compression of the sciatic nerve produced a major reduction in motor function as assessed by SSI. Improvement was observed by day 7. By day 20, SSI was completely restored. CONCLUSIONS: This technique is simple to use, quick, without expensive technical equipment. It provides good accuracy and precise quantification of the extent of functional loss and recovery after sciatic nerve injury.

Animals↗
PubMed2004

[Diagnosis and surgical treatment for small-sized peripheral lung cancer].

Small-sized peripheral lung cancers have been detected more frequently as a result of recent developments in diagnostic imaging including high-resolution computed tomography (HRCT). Although the diagnosis of small-sized peripheral lung cancers is difficult, it makes an adequate diagnosis possible using transbronchial fine needle aspiration cytology or a new thin-type bronchoscope. Surgical treatment using mini-thoracotomy or video-assisted thoracic surgery is effective for early stage small-sized peripheral lung cancers. Lesser resection of lung cancer may provide many benefits to patients, such as preserving vital lung tissue and providing the chance for further resection if a second primary lung cancer develops, however, lobectomy with systematic hilar and mediastinal lymph node dissection should remain the standard surgical treatment, and an intentional limited resection should be adopted for very limited patients with a definitive early stage because of recurrence rates.

Biopsy, Fine-Needle↗
PubMed1984

Synovial sarcoma in childhood.

The clinical and radiologic findings in seven children with synovial sarcoma are described. The five boys and two girls had a mean age at presentation of 4.4 years. All seven had the lesion situated in an extremity. Plain radiographs in four revealed the presence of a soft-tissue mass with no calcification or bone and joint involvement. In two patients studied with computed tomography (CT), the primary lesions had peripheral irregular areas of enhancement with central areas of poor enhancement, reflecting the necrotic, cystic, and hemorrhagic changes found in the centers of these tumors. Although the exact margins of these lesions were difficult to define accurately even with intravenous contrast enhancement, CT is still recommended as the best imaging method for assessing the local extent of the primary tumor and is a useful tool in the planning of appropriate therapy as well as the gauging of tumor response to ongoing treatment.

Age Factors↗
PubMedDate not supplied

Pitfalls in CT evaluation of chest wall invasion by lung cancer.

Computed tomography in a patient with a peripheral lung cancer in the right upper lobe revealed obliteration of the extrapleural fat and direct connection of the tumor with an intercostal soft tissue mass of similar density. The findings were suggestive of chest wall invasion by the cancer which was, however, proven to be false after en bloc resection of the tumor and the contiguous chest wall. Such a diagnostic pitfall could be avoided if special attention were paid to the asymmetry of the CT image at the level of upper thoracic outlet due to improper positioning of the patient.

Adenocarcinoma↗
PubMed1990

Impedance plethysmography: basic principles.

Impedance Plethysmography technique has been discussed with explanation of two compartment model and parallel conductor theory for the estimation of peripheral blood flow and stroke volume. Various methods for signal enhancement to facilitate computation of blood flow are briefly described. Source of error in the estimation of peripheral blood flow is identified and the correction has been suggested.

Humans↗
PubMed2006

A computational system to optimise noise rejection in photoplethysmography signals during motion or poor perfusion states.

Photoplethysmography (PPG) signals can be used in clinical assessment such as heart rate (HR) estimations and extraction of arterial flow waveforms. Motion artefact and/or poor peripheral perfusion can contaminate the PPG during monitoring. A computational system is presented here to minimise these two intrinsic weaknesses of the PPG signals. Specifically, accelerometers are used to detect the presence of motion artefacts and an adaptive filter is employed to minimise induced errors. Zero-phase digital filtering is engaged to reduce inaccuracy on the PPG signals when measured from a poorly perfused periphery. In this system, a decision matrix adopts the appropriate technique to improve the PPG signal-to-noise ratio dynamically. Statistical analyses show promising results (maximum error < 7.63%) when computed HR is compared to corresponding estimates from the electrocardiogram. Hence, the results here suggest that this dual-mode approach has potential for use in relevant clinical measurements.

Artifacts↗
PubMed1998

Macronodular multi-organs tuberculoma: CT and MR appearances.

The case of a 21-year-old woman presenting with macronodular multi-organs tuberculoma is reported. She was examined for pulmonary tuberculosis on a chest X-ray film in January, 1995, and admitted with a cough, anorexia, and abdominal pain in July, 1996. Computed tomography revealed multiple calcified nodules with peripheral hypodense areas in the brain, and calcified hypodense masses in the liver and spleen. Magnetic resonance (MR) imaging showed hypointense masses in the liver and spleen on T1-weighted spin echo images and a hypointense mass with a hyperintense area on T2-weighted spin echo images. On contrast-enhanced dynamic MR images, the liver and spleen masses were unenhanced and hypointense with slight rim enhancement. T2-weighted spin echo images showed a round hypointense nodule in the right kidney and hydronephrosis and enlargement in the left kidney. Antituberculous treatment was started with a gradual improvement in her signs and symptoms. Her temperature became normal. However, she was systemically treated with antituberculous chemotherapy 10 months later, her condition worsened again. She died from increased intracranial pressure in August, 1997.

Adult↗
PubMed1999

Three-dimensional computed tomographic angiography in lower extremity revascularization.

To evaluate the role of three-dimensional computed tomographic angiography (3D-CT) in peripheral artery bypass surgery, 49 patients with chronic lower limb ischemia underwent 3D-CT before and after a bypass operation. 3D-CT had a sensitivity of 96.8%, a specificity of 95.0% and an overall accuracy of 96.1% for the diagnosis of arterial and graft stenosis or obstructions. The ability to observe the acquired images at any angle was very useful for assessing the implanted graft in both aortoiliac and infrainguinal bypasses. Although these images equally identified arterial stenosis, obstruction, and the anastomotic morphology of bypass grafts as well as conventional angiography, the diagnostic accuracy was not helpful in the small arteries and grafts. 3D-CT is a low-invasive imaging method that is sufficient for forming strategies for bypass operations. In aortofemoral or femoropopliteal bypass surgery, 3D-CT thus provides sufficient imaging accuracy for bypasses up to the popliteal artery below the knee in patients with chronic limb ischemia.

Aged↗
PubMed1979

Computer analysis of defined populations of lymphocytes irradiated in vitro. III. Evaluation of human T and B cells of peripheral blood origin.

The radiosensitivities of lymphocytes of peripheral blood origin obtained from two healthy 45 year old male donors were studied simultaneously at yearly intervals over a three year period. Hypaque-Ficoll purified cells were exposed in vitro to 0, 5, 50, and 500 rads and then evaluated serially for viability of T and B cells, responsiveness to PHA and Con A, and morphologic evidence of injury as documented by standard light microscopy and computer assisted morphometric analysis. The results showed that T cells in both subjects were less radiosensitive than B cells. Differences between the two subjects also existed in the radiosensitivity of these two subpopulations of lymphocytes, differences that remained constant over the three years period of observation. The differences correlated with similar discrepancies in mitogenic responsiveness and are thought to relate to variations in the relative proportions of subpopulations of T and B cells. In the mouse, T and B cell subpopulations differ in radiosensitivity. The data reported herein are consistent with a similar situation in man.

Adult↗
PubMed2006

Alkaline comet assay study with breast cancer patients: evaluation of baseline and chemotherapy-induced DNA damage in non-target cells.

The sensitivity of the alkaline comet assay for the evaluation of baseline and treatment-induced DNA damage in white blood cells of breast cancer patients receiving adjuvant chemotherapy according to three conventional anthracycline- and cyclophosphamide-containing protocols was investigated. Additionally, baseline DNA damage in cancer patients was compared with the levels of DNA damage recorded in healthy women. Altogether 30 patients with diagnosed breast cancer and 30 female blood donors with no known familial history of breast cancer participated in the study. Alkaline comet assay was performed according to standard protocol and DNA migration in peripheral blood leukocytes was measured by a computer-based image analysis system. For each subject the frequency of "damaged" cells, i.e., long-tailed nuclei (LTN) with tail length exceeding 95th percentile for the considered parameter among controls, is also reported. Breast cancer patients had significantly increased background levels of DNA damage in their peripheral blood leukocytes as compared to healthy women. Prior to the chemotherapy, a majority of patients showed a statistically significant increase in the number of LTN compared to healthy blood donors. Marked interindividual variations in baseline DNA damage among patients were recorded, some of them related to the disease stage and status. The present study confirmed the alkaline comet assay as a sensitive technique able to detect significantly elevated DNA migration in blood cells of patients already one hour after completion of the first cycle of chemotherapy. Administration of antineoplastic drugs in three chemotherapy protocols studied induced a similar increase of primary DNA damage in nontarget cells. The evaluation of the LTN frequencies indicates the best response to the protocol containing cyclophosphamide, methotrexate and 5-fluorouracil (CMF). Our results point to the significance of simultaneous evaluation of DNA migration and frequency of LTN in the same subject and approved the use of alkaline comet assay as a suitable method for the routine detection of critical DNA lesions produced after administration of antineoplastic drugs in the clinical settings.

Adult↗
PubMed2006

Dual-channel photoplethysmography to monitor local changes in vascular stiffness.

OBJECTIVES: Monitoring arterial distensibility changes is important to understand the cardiovascular status of patient. Pulse transit time (PTT), which is an inverse equivalent of pulse wave velocity (PWV), has shown its potential in such studies. However, its methodological approach in using an electrocardiogram and a peripheral photoplethysmography (PPG) is limited due to the inclusion of pre-ejection period (PEP) in its computation. Previous studies have suggested the using the transit time difference between two peripheral measuring sites (PTT-D) instead. However, it requires two medical instruments and may not be efficient in terms of equipment utility, especially in prolonged clinical studies. METHODS: Postural changes are known to cause complex haemodynamics adaptation and thereby affecting transit time measurements. A customised dual-channel PPG system based on discrete electronic devices was constructed to evaluate against conventional peripheral-based PTT. 10 healthy adults (7 male; mean age 27.0 yr) were recruited to assess the differences observed in PTT and PTT-D during two postural change test activities. RESULTS: PTT-D derived from the customised PPG system registered 43.3+/- 5.6 ms and - 31.1+/- 3.8 ms relative changes for the two regulated activities while conventional PTT recorded 43.6+/- 10.3 ms and -31.0+/-m 6.5 ms respectively. The former may have similar results but have significantly lower variance (< 0.05). CONCLUSIONS: Findings herein suggest that PTT-D derived from the customised PPG system shows potential. It can be used as an alternative to conventional peripheral-based PTT and possibly as a direct assessment of arterial distensibility or PWV variations as it does not include PEP in its time-related computations.

Adult↗
PubMed2000

Seasonal variation of availability of serotonin transporter binding sites in healthy female subjects as measured by [123I]-2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane and single photon emission computed tomography.

BACKGROUND: Previous studies have indicated annual variations in central and peripheral serotonergic activity. In the present study we studied five women in summer and six women in winter and evaluated possible differences in availability of brain serotonin transporters between summer and winter. METHODS: We employed the single photon emission computed tomography ligand [123I]-2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane ([123I] beta-CIT) to visualize binding to the serotonin transporter site in the human thalamus/hypothalamus midbrain area in vivo. Brain imaging studies were performed in one group between May and August and in the other between November and December. RESULTS: We found significant differences in displaceable [123I] beta-CIT binding in the region corresponding to thalamus/hypothalamus between the summer group and the winter group (1.9 +/- 0.3 vs. 1.4 +/- 0.2, respectively; p < .01). CONCLUSIONS: The results of the present study suggest reduced brain serotonin transporter availability in winter. This finding further substantiates evidence of seasonal variations in brain serotonergic function.

Adult↗
PubMedDate not supplied

The use of digital epiluminescence dermatoscopy to identify peripheral scaling in pityriasis rosea.

Non-digital epiluminescence dermatoscope (ED) is a skin surface microscope utilizing oil immersion. Digital ED achieves epiluminescence by cross-polarization, with real-time images shown on computer screen.Non-digital and digital ED can assist to identify peripheral scaling in pityriasis rosea (PR). Additional advantages of digital ED include higher magnifications, a dry and convenient procedure, direct patient involvement, and easy appreciation of the relationship between microscopic changes and macroscopic clinical signs. PR is a particularly good teaching model as the histopathological changes almost exactly mirror changes seen under digital ED. Digital ED also allows easy image storage for record keeping, teaching and research.

Dermatology↗
PubMedDate not supplied

Diagnosis of a porto-azygous shunt using helical computed tomography angiography.

Congenital portosystemic shunts occur uncommonly in dogs. Conventional diagnostic methods either do not offer simultaneous diagnosis and anatomic characterization or require an invasive selective catheterization. Helical computed tomography (HCT) is a rapid, noninvasive means of acquiring cross-sectional images of any portion of the body. Combined with a peripheral venous injection of contrast medium, HCT can produce computer-rendered, "angiogram-like" images of vasculature. These computer-generated multiplanar and three-dimensional HCT angiographic images were helpful in the diagnosis and accurate anatomic characterization of a porto-azygous shunt. A brief discussion of scanner and contrast medium protocol considerations necessary to achieve adequate vascular opacification for volumetric data reconstructions and diagnosis are outlined.

Angiography↗