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Biomedical subjects

A G Bergman

Publications and source records attributed to A G Bergman.

At least 37 records · Page 2Linked to original sources
PubMed1994

Osteoarthritis of the knee: correlation of subchondral MR signal abnormalities with histopathologic and radiographic features.

Subchondral signal abnormalities are often present on magnetic resonance (MR) images of patients with osteoarthritis, but no study correlating these changes with histopathology has been published. We selected nine consecutive patients with clinical and radiographic diagnosis of moderate to severe osteoarthritis of the knee scheduled to undergo joint replacement surgery, and performed MR imaging and conventional radiographs preoperatively. After surgery, the resected portions of the femur and tibia underwent gross and microscopic examination, and the findings were correlated with the corresponding findings on the imaging studies. Subchondral MR signal abnormalities of the femur or tibia were present in seven of the nine patients, with intermediate signal on T1-weighted images and low or isointense signal on T2-weighted images. The subchondral signal abnormalities were hemispherical in configuration and corresponded predominantly to fibrous tissue replacing the fatty marrow. A component of trabecular thickening was also present.

Aged↗
PubMed1994

Pediatric elbow fractures: MRI evaluation.

Magnetic resonance imaging (MRI) was performed in eight patients under the age of 8 years who suffered elbow fractures, to assess possible fracture extension into the distal nonossified epiphysis of the humerus in seven cases and to determine the displacement and location of the radial head in one case. MRI allowed accurate depiction of the fracture line when it extended into the cartilaginous epiphysis. In four cases, MRI findings were confirmed at surgery. In five cases, surgery was obviated because no articular extension of the fracture was seen on MRI (4 cases) or because no displacement was noted (1 case). In one patient, the plain film diagnosis of a Salter type II fracture was changed to Salter type IV on the basis of the MRI findings. It is concluded that MRI might play a role in the preoperative evaluation of pediatric patients presenting with elbow trauma when extension of the fracture cannot be determined with routine radiographic studies. Elbow injuries in children may be difficult to diagnose by routine clinical and radiographic techniques [1, 4, 12, 14]. Diagnostic difficulty is due to the presence of multiple ossification centers of the distal humeral epiphysis and proximal radius and ulna; these are mostly cartilaginous until the age of 11-12 years and therefore invisible on radiographs. Following distal radial and distal tibial physeal fractures, epiphyseal elbow injuries are the most frequent epiphyseal injuries [8, 16]. These fractures tend to be unstable and often require surgical intervention. In addition, lasting sequelae such as cubitus valgus and delayed ulnar nerve palsy can occur if these fractures are not treated properly [8].(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1994

Association of glenoid labral cysts with labral tears and glenohumeral instability: radiologic findings and clinical significance.

PURPOSE: To determine the relationship between labral cysts and labral tears and glenohumeral instability. MATERIALS AND METHODS: Magnetic resonance (MR), clinical, and arthroscopic examinations of the shoulder and the surgical findings of 20 patients were correlated and retrospectively analyzed. A cystic-appearing mass adjacent to the labrum was the selection criterion for inclusion. RESULTS: MR imaging showed labral tear intimately associated with cystic-appearing mass in these 20 patients. The tear and cyst complex was located anteriorly in two patients, posteriorly in nine, and superiorly in nine. The mass extended into the spinoglenoid notch in six patients, the suprascapular notch in three, and both notches in four. Physical examination showed glenohumeral instability in the direction of the labral tear and cystic-appearing mass in 11 patients (55%). Findings at intraarticular surgery, performed in eight patients, confirmed a labral tear with communication between the joint space and the cyst. CONCLUSION: Glenoid labral cysts are associated with glenoid labral tears and shoulder instability.

Adult↗
PubMed1994

Magnetic resonance imaging manifestations of synovial lesions of the ankle and foot.

Inflammatory, infectious, neoplastic, degenerative, or idiopathic disorders may all be manifested as synovial disease. MR imaging allows noninvasive evaluation of synovial disease and is a highly sensitive modality for detection of synovial pathology. Intravenous or intra-articular contrast administration will sometimes further increase signal differences between inflamed synovium, joint effusion, and surrounding structures.

Ankle Joint↗
PubMed1993

Dupuytren's contracture: MR imaging findings and correlation between MR signal intensity and cellularity of lesions.

OBJECTIVE: Dupuytren's contracture is a common fibrosing disorder of the hand which often results in progressive and debilitating flexion contractures of the fingers. Recurrence after surgical release is common and may be related, in part, to the cellularity of the lesion. We describe the MR appearance of Dupuytren's contracture and correlate signal characteristics with the degree of cellularity of the lesion. SUBJECTS AND METHODS: A total of 11 hands in 10 patients were studied. All patients had surgical resection after MR imaging (median interval, 3 days). The surgical and pathologic findings were correlated with the MR findings. The signal characteristics of the lesions were correlated with the histologic findings. RESULTS: We found that MR imaging was accurate for detecting Dupuytren's contracture and depicting its extent. The lesions include subcutaneous nodules, usually at the level of the distal palmar crease, and cords that lie parallel and superficial to the flexor tendons. The cords had a uniformly low signal intensity (similar to the signal intensity of tendon) on both T1- and T2-weighted images in 18 of 22 cases, whereas the remaining four cases had a low to intermediate signal intensity on T1-weighted images (a slightly higher signal intensity than that of tendon) and a low signal intensity on T2-weighted images. Histologically, the cords were hypocellular and composed of dense collagen. Most nodules had an intermediate signal intensity (similar to that of muscle) on both T1- and T2-weighted images (10 of 13 cases), usually stippled with focal areas of lower signal intensity. Histologically, these nodules were mostly cellular. Three of the nodules had a low signal intensity on both T1- and T2-weighted images and were hypocellular histologically. CONCLUSION: We conclude that MR imaging can be used to define palmar involvement in Dupuytren's contracture. The signal characteristics of the lesions correlate with the degree of cellularity of the lesions as seen histologically. The ability to assess preoperatively the cellularity of lesions of Dupuytren's contractures may be of prognostic significance, because highly cellular lesions tend to have higher rates of recurrence after surgery than do hypocellular lesions.

Adult↗
PubMed1987

Nosocomial infection by gentamicin-resistant Streptococcus faecalis. An epidemiologic study.

Enterococci with high-level resistance to gentamicin account for 55% of clinical isolates of enterococci found in patients at the Ann Arbor Veterans Administration Medical Center. We prospectively studied cultures obtained from all 100 patients hospitalized from 1 December 1985 through 23 January 1986 on the surgical and thoracic intensive care units and a general medical floor. Ten patients' cultures grew colonies of gentamicin-resistant enterococci--six after admission to the intensive care units and four after hospitalization on the medical ward. The initial sites of colonization were the rectal and perineal areas in seven patients, sternal wound in one, urine in one, and the rectal and perineal areas as well as urine after Foley catheter insertion in one. Nine patients died and three of the deaths were associated with enterococcal infection. The acquisition of resistant strains was associated with previous and more frequent exposure to antimicrobial agents, and with geographic clustering of patients. Resistant enterococci were isolated from the hands of hospital personnel and were frequently isolated from environmental surfaces. Nosocomial acquisition and interhospital spread of gentamicin-resistant enterococci was shown to have occurred when plasmid content was used as an epidemiologic marker.

Adult↗
PubMed1984

Fever in the elderly. Production of leukocytic pyrogen by monocytes from elderly persons.

In an attempt to explain the diminished febrile response of the elderly, we studied the first step in fever generation, that of production of leukocytic pyrogen (LP) by monocytes. Monocytes from 25 healthy elderly volunteers (ages 65-91) and 24 healthy young volunteers (ages 17-38) were stimulated with Staphylococcus epidermidis to release LP; LP activity in the culture supernatants was assayed by measuring the pyrogenic response in rabbits and rats and the fall in plasma iron and zinc in rats. Monocytes from elderly volunteers produced slightly less LP than monocytes from young volunteers, but the difference was not statistically significant. The amount of LP produced was not correlated with age. Therefore, the diminished febrile response of the elderly is not the result of an intrinsic defect in the monocyte's ability to make LP. Other explanations relating to the central effect of LP and the effector response to LP in the elderly should be sought.

Adolescent↗
PubMed1984

Efficacy of ketoconazole v nystatin in prevention of fungal infections in neutropenic patients.

A prospective randomized study was undertaken in neutropenic patients to evaluate the efficacy of prophylactic ketoconazole v nystatin in reducing yeast infections. Eighteen patients received 500,000 units of nystatin suspension four times daily, and 18 patients received 200 mg of ketoconazole daily. The nystatin group experienced nine local yeast infections (four thrush, three esophagitis, and two vaginitis); three patients receiving ketoconazole had thrush. No cases of disseminated candidiasis occurred in either group. Ketoconazole was better tolerated than nystatin and neither drug caused toxic effects. In addition to being nontoxic and better tolerated, ketoconazole appeared to be slightly more effective than nystatin in reducing locally severe yeast infections.

Adult↗
PubMed1984

Dermatitis due to Sporobolomyces infection.

A 30-year-old woman had a pruritic skin lesion from which a yeastlike organism, Sporobolomyces holsaticus, was isolated. Members of this group of yeasts are found in the soil throughout the world and have been implicated only twice before in human infection. We report a third case of infection due to a Sporobolomyces organism.

Adult↗
PubMed1982

Distemper virus infection in ferrets: an animal model of measles-induced immunosuppression.

Distemper virus is very similar antigenically to measles virus, and the disease produced in ferrets by distemper is a systemic illness quite similar to measles infection in humans. Using an attenuated strain of distemper virus, we produced a mild systemic illness in ferrets and were able to study the effects of the viral infection on cell-mediated immunity (CMI). Beginning on day 5 after viral inoculation and continuing to day 30, infected ferrets showed a marked lymphopenia, with a reduction in total numbers of all lymphocyte subpopulations studied. Transformation of circulating lymphocytes to the mitogens phytohemagglutinin, concanavalin A, and pokeweed mitogen was suppressed on day 5, reached a nadir by days 8 to 11, and returned toward normal by days 23 to 30 after viral inoculation. Production of macrophage migration inhibitory factor by splenic macrophages was diminished during distemper infection. In contrast to marked suppression of these in vitro assays for CMI, delayed hypersensitivity skin test responses were only slightly diminished in animals infected with distemper virus. This model should prove useful in exploring the mechanisms of measles induced immunosuppression.

Animals↗
PubMed1981

Detection of cryptococcal antigen. Comparison of two latex agglutination tests.

The detection of cryptococcal antigen by means of the agglutination of antibody-coated latex particles is an important aid in the diagnosis of cryptococcosis. A commercially available latex agglutination test (IBL kit) was compared with the latex agglutination test from the Center for Disease Control in regard to sensitivity, specificity, and height of antigen titer. Over a 13-month period, 335 specimens were tested with both kits. There was one false-positive reaction with both kits (0.4%) and one false-negative reaction only with the CDC kit, among 18 patients who had meningitis or disseminated infection due to Cryptococcus neoformans. Sera from patients who had localized pulmonary cryptococcosis showed negative results with both kits. The antigen titers measured by the two kits were the same or within two dilutions in 22 of 26 specimens of cerebrospinal fluid or serum from patients who had proved cryptococcosis. Overall, the IBL kit compared favorably with the CDC kit for the detection of cryptococcal antigen in cerebrospinal fluid or serum.

Antigens, Fungal↗
PubMed1979

Antimicrobial resistance of Haemophilus species in patients with chronic bronchitis.

Haemophilus influenzae strains resistant to ampicillin have become an important cause of disease in pediatric patients. Because many adults with chronic bronchitis carry Haemophilus organisms in their tracheobronchial tree and because antimicrobial agents are used commonly in these patients, we assessed the prevalence of resistance to ampicillin and other antimicrobial agents in this population. We studied 150 Haemophilus isolates (73 H. influenzae, 69 H. parainfluenzae, 6 H. parahemolyticus, and 2 H. hemolyticus) obtained from 138 patients with chronic bronchitis from January 1978 through March 1979. Ampicillin resistance due to production of beta-lactamase was found in 7 of the 150 isolates (4.7 %)-2 H. influenzae, 4 H. parainfluenzae and 1 H. parahemolyticus. Resistance to tetracycline was found in 9 strains (6 %), but all strains were susceptible to chloramphenicol.

Adult↗