Biomedical subjects

J D Collins

Publications and source records attributed to J D Collins.

At least 55 records · Page 3Linked to original sources

PubMed1992

Fluoroscopic chest tube insertion and patient care.

Catheters and chest tubes may be placed under fluoroscopic control to reduce pleural effusions. This procedure has been adopted as a routine procedure at the UCLA School of Medicine in Los Angeles, California to improve patient care. This technique was modified for the placement of large chest tubes, which can be placed by a radiologist without multiple attempts or complications. Our experience with 2234 patients who underwent this procedure between 1977 and 1990 is described.

Catheterization↗

PubMed1991

Mediastinal masses: magnetic resonance imaging in comparison with computed tomography.

Seventy-eight patients with mediastinal abnormalities were imaged with magnetic resonance imaging (MRI) to evaluate mediastinal masses and associated lung, pleural, or chest wall disease. Magnetic resonance images were compared with computed tomography (CT) scans, which were available in 45 patients. While MRI and CT were equally effective in demonstrating mediastinal lesions, CT was superior for displaying calcification within a mass in eight patients and for demonstrating associated lung abnormality in four patients. Computed tomography should remain the imaging procedure of choice after chest radiography to evaluate mediastinal masses, although MRI may be indicated in selected patients.

Adolescent↗

PubMed1991

Magnetic resonance imaging of chest wall lesions.

Magnetic resonance imaging (MRI) demonstrates surface anatomy, nerves, and soft tissue pathology. Selective placement of the cursor lines in MRI displays specific anatomy. The MR images can then be used as adjunct in teaching surface anatomy to medical students and to other health professionals. Because the normal surface anatomy could be imaged at UCLA's radiology department, it was decided to image soft tissue abnormalities with MR to assist in patient care. Patients imaged were scheduled for special procedures of the chest or staging lymphangiograms. Patients were placed into categories depending on known diagnosis or interesting clinical presentation. The diagnostic categories included Hodgkin's disease, melanoma, carcinomas (eg, lung or breast), lymphedema, sarcomas, dermatological disorders, and neurological disorders. All images were orchestrated by the radiologist. This article discusses both the teaching and clinical impact on patient care.

Adult↗

PubMed1991

Anatomy of the thorax and shoulder girdle displayed by magnetic resonance imaging.

In 1971, radiographic anatomy of the human body was added to the gross anatomy course at UCLA. Radiographic contrast studies and plain anatomical displays were formulated into teaching packages for all organ systems. Residents presented each package to first-year medical students in the dissection laboratory to augment the teaching of anatomy. In November 1984, magnetic resonance imaging was instituted in the radiology department. Imaging the chest produced coronal and axial planes which displayed the muscles and soft tissues of the thorax. In 1986, the authors presented their study of MR anatomy of the chest and shoulder girdle to the American Association of Anatomists. The purpose of this presentation is to demonstrate the anatomy of the thorax and shoulder girdle as displayed by magnetic resonance, correlated with regional anatomy, with emphasis on soft tissue structures.

Humans↗

PubMed1990

Factors responsible for the introduction and spread of Campylobacter jejuni infection in commercial poultry production.

Campylobacter jejuni and related thermophilic campylobacters were not found in a hatchery or in chicks aged less than seven days. However, an increasing proportion of chicks aged two weeks and older shed campylobacters in their droppings. It was shown that a likely source of C jejuni for young chicks was the environment in the immediate vicinity of the rearing houses, and that infection could readily be introduced on the footwear and clothing of farm staff. Thermophilic campylobacters were found in the air, litter and drinking water containers in the rearing and finishing houses.

Air Microbiology↗

PubMed1990

Low prevalence of antibody to hepatitis C virus in north east England.

The prevalence of antibodies to hepatitis C virus (anti-HCV) was studied in North East England in blood donors, local multiply transfused patients, local high risk individuals, and chronic liver disease patients. Anti-HCV was detected by enzyme-linked immunosorbent assay (ELISA) in 2/1120 (0.18%) blood donors; 1/84 chronic renal failure patients on haemodialysis who had received 1,992 units of blood (seroconversion rate of 0.05% per unit transfused), 1/207 cardiac patients 6 months post cardiac surgery transfused with 1,403 units of blood (1 anti-HCV pre-operatively, seroconversion rate 0.07%), 40/50 haemophilia A patients treated with commercial factor VIII, and 38/100 intravenous drug users. In addition anti-HCV was detected by ELISA in 5/35 cryptogenic chronic liver disease patients, 5/5 confirmed by recombinant immunoblot assay (RIBA) (14%); 3/30 patients with autoimmune chronic active hepatitis, 2/3 by RIBA (7%); 2/50 primary biliary cirrhosis patients, 1/2 by RIBA (2%); 0/30 alcoholic cirrhosis patients; and 2/9 patients with hepatocellular carcinoma, 1/2 by RIBA (11%). HCV is uncommon in North East England; it may be implicated in the aetiology of a minority of cases of cryptogenic liver disease and less than 5% of autoimmune chronic active hepatitis and primary biliary cirrhosis.

Factor VIII↗

PubMed1990

Enhancing magnetic resonance images using water bags.

Fascial planes between tissues are separated by connective tissue, fat, and blood vessels. Magnetic resonance imaging displays surface anatomy and soft tissues. Our team has been successful in demonstrating brachial plexus nerves as a model of magnetic resonance anatomy. Radiologists have devised methods to increase the resolution of images by suppressing noise and increasing the sharpness of the image. We added water bags to a 0.3 tesla permanent magnet suppressing the noise and increasing the signal to image our patients. The images proved to be sharper.

Humans↗

PubMed1990

Lung biopsies and patient care at university-affiliated hospitals: a 20-year experience.

Lung biopsies have been performed since 1967 at the University of California at Los Angeles and its affiliated institutions. In the span of 20 years, the author performed 4285 cases and developed several procedures. This article discusses the importance of risk management and patient care and presents statistics on malignancies, complications, and contraindications.

Biopsy↗

PubMed1989

Mediastinal germ cell tumor in a young woman.

Primary mediastinal germ cell malignancies are uncommon neoplasms, usually presenting in young men. We review a case of a primary mediastinal seminoma occurring in a 23-year-old woman. The differential diagnosis, work-up and therapy for these lesions is discussed with emphasis on the role of magnetic resonance imaging in the evaluation of anterior mediastinal masses.

Adult↗

PubMed1989

Why is high resolution computerized tomography scanning used in evaluating the lungs?

High resolution computerized tomography scans have been used for medical and legal purposes to evaluate patients with a history of exposure to asbestos. Some investigators argue that high resolution scanning provides a better image of the lungs than routine computerized tomography. A review of the literature shows that although high resolution scanning displays the lymphatics in the lung, it offers no new useful diagnostic information. The authors conclude that no real advantage is attained with high resolution scanning of the lung and that pathology of disease can be determined decisively only by histology.

Evaluation Studies as Topic↗

PubMed1989

Nerves on magnetic resonance imaging.

Nerves are often visualized on magnetic resonance imaging (MRI) studies of the soft tissues on the chest and shoulder girdle. To learn the reasons for the contrast between the nerves and adjacent tissues, the authors obtained a fresh specimen containing part of the brachial plexus nerves from the left axilla and compared MRI with x-ray projections and photomicrographs of histologic sections. The results suggest that the high signals from the nerves stand out in contrast to the low signals from their rich vascular supply.

Connective Tissue↗

PubMed1989

Anatomy of the abdomen, back, and pelvis as displayed by magnetic resonance imaging: Part One.

In April 1986, magnetic resonance imaging (MRI) of the thorax and shoulder girdle was presented to the 99th Annual Meeting of the American Association of Anatomists. These images were the authors' first attempt to correlate the magnetic resonance display of the muscles and soft tissues of the chest in the coronal plane with surface gross anatomy. The original purpose of this study was to introduce the role of magnetic resonance imaging to anatomists, medical students, and the specialty of radiology. However, this approach has been expanded by imaging other sections of the body and applying the display of surface anatomy to augment the teaching of anatomy to surgical oncology, pathology, and kinesiology. This three-part article will display magnetic resonance images and will explain how magnetic imaging of the soft tissues can visually augment the teaching of gross anatomy without dissecting surface tissues.

Abdomen↗

PubMed1989

Anatomy of the abdomen, back, and pelvis as displayed by magnetic resonance imaging: Part Two.

In April 1986, magnetic resonance imaging (MRI) of the thorax and shoulder girdle was presented at the 99th Annual Meeting of the American Association of Anatomists. These images were the authors' first attempt to correlate the magnetic resonance display of the muscles and soft tissues of the chest in the coronal plane with surface gross anatomy. The original purpose of this study was to introduce the role of magnetic resonance imaging to anatomists, medical students, and the specialty of radiology. However, this approach has been expanded by imaging other sections of the body and applying the display of surface anatomy to augment the teaching of anatomy to surgical oncology, pathology, and kinesiology. This three-part article will display magnetic resonance images and will explain how magnetic imaging of the soft tissues can visually augment the teaching of gross anatomy without dissecting surface tissues.

Abdomen↗

PubMed1989

Anatomy of the abdomen, back, and pelvis as displayed by magnetic resonance imaging: part three.

Abdomen↗

PubMed1988

Safety, tolerance and pharmacokinetics of 2.0 g cefpirome (HR 810) after single and multiple dosing.

After intravenous injection of a single dose of 2.0 g cefpirome (HR 810) and multiple doses of 2.0 g b.i.d. (11 doses) to 10 healthy male volunteers in an open design, concentrations of unchanged drug were measured at various times in serum and urine over 24 and 96 h, respectively. Cefpirome concentrations were determined using high-pressure liquid chromatography (HPLC). The biological half-life (t1/2, beta) found by fitting a two-compartment open model to the data was 2 h. No accumulation of the serum levels could be detected during the multiple-dose phase. Urinary concentrations of unchanged cefpirome effective against most clinically relevant bacteria were detected for at least 36 h. The drug was safe and well tolerated. No drug-related changes were observed for blood pressure, heart rate, ECG, haematology, clinical chemistry or urinalysis, including beta 2-microglobulin in serum and creatinine clearance.

Adult↗

PubMed1988

Evaluation of intrathoracic extent of lung cancer by plain chest radiography, computed tomography, and magnetic resonance imaging.

A comparison was made of the ability of plain chest radiography, computed tomography (CT), and magnetic resonance imaging (MRI) to detect and assess the intrathoracic extent of lung cancer in 46 patients. The chest radiographs (CXR) were obtained with a high kilovoltage phototimed technique. The CT scans were obtained with a GE 9800 machine and the MRI studies with a 0.3 Tesla permanent magnet imaging system. The primary tumor was well demonstrated by all 3 imaging techniques; however, the configuration of lesions was best demonstrated by CT. MRI was superior to CXR and CT for demonstrating hilar involvement in 4 cases. CT and MRI were generally comparable for demonstrating mediastinal involvement but were superior to CXR. In 2 cases, small normal size nodes seen on CT were considered to be a single large abnormal node on MRI. Because of the paucity of signal from flowing blood, compression and displacement of vessels were easier to identify with MRI. In 1 case, a small pleural effusion was better seen with CT than with CXR or with MRI. Direct chest wall involvement in 1 case was not seen by CXR. Vertebral body abnormality in another case was seen only by MRI and not by CXR or CT. At present, MRI, with its long scanning time, motion degradation of the image, and poor spatial resolution, is inferior to CT for imaging lung cancer. For evaluation of intrathoracic extent of lung cancer, CT remains the procedure of choice after performing plain chest radiography.

Adult↗

PubMed1988

Pharmacokinetics of roxatidine in healthy volunteers.

This paper reviews those studies which investigated the absorption, distribution, metabolism and elimination of roxatidine acetate (formerly HOE 760) following its single and multiple oral administration to healthy male and female volunteers. Roxatidine acetate is almost completely (greater than 95%) absorbed after oral administration and is rapidly converted to roxatidine, its major active plasma and urinary metabolite. In common with many other prodrugs, the parent substance is not detectable in either plasma or urine and therefore all pharmacokinetic studies have been evaluated using measurements of roxatidine. A powder capsule formulation of the drug showed rapid absorption (tmax = 1 hour) and linear pharmacokinetics across the dose range 25 to 100mg, but produced some gastrointestinal intolerance. However, a granulated capsule formulation showed a much slower release (tmax = 3 hours) and was well tolerated. There was no evidence of any food interaction or interaction with other drugs such as antipyrine and propranolol. The plasma terminal half-life of the granulated capsule averaged 6 hours and between 55 and 60% of the dose was recovered in the urine as roxatidine. Following repeated daily administration of the prodrug, steady state plasma levels of roxatidine were reached on average by the fourth dose.

Adolescent↗

PubMed1988

Therapeutic approach in patients with concomitant disease/drug--drug interactions (roxatidine acetate).

Possible mechanisms of drug interactions with H2-antagonists are outlined. The mode of action of roxatidine acetate on hepatic microsomal enzymes is contrasted with those of cimetidine and ranitidine, and their differing structure-activity relationships are discussed. In the light of the mechanisms of drug interactions with H2-antagonists, clinical studies with roxatidine acetate are contrasted with published interaction data of cimetidine and ranitidine. The therapeutic consequences of these data are considered.

Anti-Ulcer Agents↗