Biomedical subjects

J A Jacobson

Publications and source records attributed to J A Jacobson.

116 records · Page 7Linked to original sources

PubMedDate not supplied

Risk of developing toxic shock syndrome associated with toxic shock syndrome toxin 1 following nongenital staphylococcal infection.

Few risk factors for nonmenstrual toxic shock syndrome (TSS) have been identified. This study sought to determine at what rate and under what circumstances nongenital toxigenic Staphylococcus aureus infections led to TSS. Clinical isolates of S. aureus were examined for the production of TSS toxin 1 (TSST-1), and available sera from infected patients were tested for antibody to this toxin. Twenty-six percent of 810 isolates produced TSST-1. Isolates from children were more likely to be positive for TSST-1 than were those from adults. None of 57 patients with TSST-1-positive staphylococcal infection and a TSST-1 antibody titer of greater than or equal to 1:100 developed TSS. Eight of 65 tested patients with TSST-1-positive isolates had antibody below the presumably protective level of 1:100. Two of these patients had definite TSS, three had probable or possible TSS, and three probably did not have TSS. In patients lacking protective antibody to TSST-1, the interval between acquisition and infection with staphylococci, the type and amount of toxins produced, the site of infection, and still-unclarified aspects of host susceptibility may all affect the rate and severity of TSS.

Adult↗

PubMedDate not supplied

The Bennett lesion of the shoulder.

In this article we review the imaging features and significance of the Bennett lesion of the shoulder. Standard radiographic, computed arthrotomographic, and MR findings in three baseball pitchers diagnosed with Bennett lesions of the shoulder are discussed. A crescent-shaped region of mineralization at the posteroinferior aspect of the glenoid rim, consistent with a Bennett lesion, arises at the insertion of the posterior joint capsule. The diagnosis of this lesion, typically in baseball pitchers, should raise suspicion for associated labral and rotator cuff abnormalities.

Adult↗

PubMedDate not supplied

MR imaging of the infrapatellar fat pad of Hoffa.

The infrapatellar fat pad of Hoffa is an intracapsular structure that is routinely visualized on magnetic resonance images of the knee. Because disease in this region is not uncommon, it is important to be familiar with the various pathologic entities that may occur here. Abnormalities that are intrinsic to this fat pad include Hoffa disease, intracapsular chondroma, localized nodular synovitis, postarthroscopy and postsurgery fibrosis, and shear injury. In addition, the infrapatellar fat pad may be involved secondarily from extrinsic processes, including articular disorders (eg, joint effusion, intraarticular bodies, meniscal cyst, ganglion cyst, cyclops lesion), synovial abnormalities (eg, pigmented villonodular synovitis; hemophilia; synovial hemangioma; primary synovial chondromatosis; chondrosarcoma; lipoma arborescens; rheumatoid, seronegative, and septic arthritis; arthritis associated with inflammatory intestinal disorders; synovitis associated with primary osteoarthritis), and anterior extracapsular abnormalities. The approach to pathologic processes involving the infrapatellar fat pad of Hoffa is simplified when one is familiar with regional anatomy and possible differential diagnostic considerations.

Adipose Tissue↗

PubMedDate not supplied

US of the ankle: technique, anatomy, and diagnosis of pathologic conditions.

For specific indications, ultrasound (US) is an efficient and inexpensive alternative to magnetic resonance (MR) imaging for evaluation of the ankle. In addition to the tendons and tendon sheaths, other ankle structures demonstrated with US include the anterior joint space, retrocalcaneal bursa, ligaments, and plantar fascia. Ankle US allows detection of tenosynovitis and tendinitis, as well as partial and complete tendon tears. Joint effusions, intraarticular bodies, ganglion cysts, ligamentous tears, and plantar fasciitis can also be diagnosed. As pressure for cost containment continues, demand for US of the ankle may increase given its lower cost compared with that of MR imaging. In most cases, a focused ankle US examination can be performed more rapidly and efficiently than MR imaging. Familiarity with the technique of ankle US, normal US anatomy, and the US appearances of pathologic conditions will establish the role of US as an effective method of imaging the ankle.

Ankle Injuries↗

PubMedDate not supplied

US of soft-tissue foreign bodies and associated complications with surgical correlation.

Ultrasonography (US) allows detection of a variety of soft-tissue foreign bodies, including wood splinters, glass, metal, and plastic, along with evaluation of their associated soft-tissue complications. Cases were obtained from the authors' clinical experience over the past 1.5 years. Surgical correlation allowed confirmation of the presence of a foreign body and associated soft-tissue complications in all cases. All of the foreign bodies were echogenic when imaged with US. A surrounding hypoechoic rim and posterior acoustic shadowing or reverberation aided detection in several cases. Associated soft-tissue complications included a complete laceration of the posterior tibial tendon and septic flexor digitorum tenosynovitis. US allows accurate and efficient detection of radiolucent soft-tissue foreign bodies and aids assessment of their associated complications. For radiopaque foreign bodies, US can provide more precise localization and improved assessment of the surrounding soft tissues. US has emerged as the study of choice for detection and localization of radiolucent soft-tissue foreign bodies and can aid assessment of their associated complications.

Adult↗

PubMedDate not supplied

Ultrasound examination of ankle injuries in children.

Fourteen children with ankle injuries, an open tibia and fibula physis, and negative radiographs had ultrasonography of their injured ankles. Five had an anterior talofibular ligament injury and five had an anterior tibiofibular ligament injury. Four had normal ultrasound examinations. Only two had a physeal injury, both of which were associated with a ligament injury. Eleven children had only lateral ankle tenderness. Ultrasound of these 11 revealed ligamentous injuries, normal examinations, and the two physeal injuries. Ligamentous injury was not associated with other tenderness patterns.

Adolescent↗

PubMedDate not supplied

Computer surveillance of hospital-acquired infections and antibiotic use.

Surveillance of hospital-acquired infections and antibiotic use is required of US hospitals. The time and cost needed to actively perform this surveillance can be extensive. We developed a computerized infectious disease monitor that automatically generates four types of surveillance "alerts" for patients with hospital-acquired infections, not receiving antibiotics to which their pathogens are susceptible, who could be receiving less expensive antibiotics, or who are receiving prophylactic antibiotics too long. Surveillance personnel using computer screening for two months found more hospital-acquired infections when compared with our traditional surveillance methods, while requiring only 35% of the time. In addition, alerts from the computer identified 37 patients not receiving appropriate antibiotics, 31 patients who could have been receiving less expensive antibiotics, and 142 patients, during one month, receiving prolonged cephalosporin prophylaxis. Computer screening can help focus the activities and improve the efficiency of hospital surveillance personnel.

Anti-Bacterial Agents↗

PubMedDate not supplied

Characteristics, control, and treatment of methicillin-resistant Staphylococcus aureus infections.

The history, in vitro characteristics, epidemiology, clinical observations, control measures, and therapy of methicillin-resistant Staphylococcus aureus (MRSA) infections are reviewed. Strains of MRSA have been implicated in nosocomial infections, particularly in hospitals associated with medical schools. In vitro, MRSA cultures usually have only a small percentage of organisms that are resistant to methicillin. Patient-specific risk factors for acquiring MRSA infections have been identified in uncontrolled and controlled studies. Environmental culturing to identify sources of contamination has been nonproductive. Physical control measures such as good handwashing and proper isolation have produced variable results in dealing with MRSA. Other suggested measures for reducing the incidence of MRSA colonization include: increasing the nurse-to-patient ratio in intensive-care units; treatment of patients and hospital employees who are colonized with MRSA; and restriction of antibiotics. The drug of choice for treating MRSA infections is vancomycin given intravenously (peripherally or centrally) or by Ommaya reservoir (for CNS infections if bactericidical concentrations are not reached with i.v. doses). Vancomycin may be used empirically for patients at high risk for developing MRSA infections before culture-and-sensitivity reports are available.

Humans↗