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Biomedical subjects

M E Mulligan

Publications and source records attributed to M E Mulligan.

At least 19 recordsLinked to original sources
PubMed2001

An episodic outbreak of genetically related Burkholderia cepacia among non-cystic fibrosis patients at a university hospital.

OBJECTIVE: To investigate an outbreak of Burkholderia cepacia. DESIGN: Observational study and chart review. PATIENTS: Adult non-cystic fibrosis (CF) patients. SETTING: Intensive care units (ICUs) at a university-affiliated teaching hospital. METHODS: As part of the epidemiological investigation, we conducted a chart review and collected environmental samples. A review of work schedules of healthcare workers also was performed. We used B. cepacia selective agar for preliminary screening for all isolates, which subsequently were confirmed as members of the B. cepacia complex by polyphasic analysis employing conventional biochemical reactions and genus- and species-specific polymerase chain reaction assays. Pulsed-field gel electrophoresis, randomly amplified polymorphic DNA typing, and automated ribotyping were used to genotype the isolates. As part of the intervention, contact isolation precautions were initiated for all patients identified as having had a culture positive for B. cepacia. RESULTS: Between September 1997 and September 1999, B. cepacia was isolated from 31 adult patients without CF in ICUs at a university-affiliated teaching hospital. Based on geographic clustering and genotypic analysis, three distinct clusters were observed involving 20 patients. Isolates from 17 of these patients were available for testing and were found to be of the same strain (outbreak strain). Further taxonomic analysis indicated that the outbreak strain was B. cepacia complex genomovar III. Twelve (71%) of the 17 patients were judged to be infected, and 5 (29%) were colonized with this strain. Six of 200 environmental cultures from multiple sources in the hospital's ICUs yielded B. cepacia. Two of these isolates, both recovered from rooms of colonized patients, were the same genotype as the outbreak strain recovered from patients. CONCLUSION: Despite an extensive investigation, the source of the B. cepacia clone involved in this outbreak remains unknown. The spatial and temporal pattern of cases suggests that cross-transmission of a genetically related strain contributed to clustering among patients. The initiation of contact isolation may have limited the extent of this transmission. Additional studies are needed to elucidate better the epidemiology of nosocomial B. cepacia infection among non-CF adult patients.

Adult↗
PubMed2000

The search for a better treatment for recurrent Clostridium difficile disease: use of high-dose vancomycin combined with Saccharomyces boulardii.

Recurrent Clostridium difficile disease (CDD) is a difficult clinical problem because antibiotic therapy often does not prevent further recurrences. In a previous study, the biotherapeutic agent Saccharomyces boulardii was used in combination with standard antibiotics and was found to be effective in reducing subsequent recurrences of CDD. In an effort to further refine a standard regimen, we tested patients receiving a regimen of a standard antibiotic for 10 days and then added either S. boulardii (1 g/day for 28 days) or placebo. A significant decrease in recurrences was observed only in patients treated with high-dose vancomycin (2 g/day) and S. boulardii (16.7%), compared with those who received high-dose vancomycin and placebo (50%; P=.05). No serious adverse reactions were observed in these patients. Comparison of data from this trial with data from previous studies indicates that recurrent CDD may respond to a short course of high-dose vancomycin or to longer courses of low-dose vancomycin when either is combined with S. boulardii.

Aged↗
PubMed2000

The in vitro efficacy of varidase versus streptokinase or urokinase for liquefying thick purulent exudative material from loculated empyema.

Patients with loculated parapneumonic effusion or empyema are sometimes treated with streptokinase or urokinase in an attempt to facilitate pleural fluid drainage by liquefying the pleural exudate and destroying the fibrin membranes producing the loculation. This study evaluated the effectiveness of streptokinase, urokinase, and Varidase (the combination of streptokinase and streptodornase) in liquefying gummy, purulent, exudative material from loculated empyemas. An empyema was created by injecting 10(8) Pasteurella multocida bacteria into the pleural space of New Zealand white rabbits. Twenty specimens, each containing 0.5 g of purulent material obtained 5 days after empyema induction, were placed in test tubes. Streptokinase (15,000 IU), urokinase (10,000 IU), Varidase (4,000-15,000 IU streptodornase + 15,000 IU streptokinase) or saline was added to five sets of four test tubes each. The amount of nonliquefied material that remained after incubation with the fibrinolytic agents was quantitated. Over the 6-h incubation period, the amount of nonliquefied material decreased from 0.5 g to 0.02 g in the Varidase group but never decreased to less than 0.4 g in any of the other three treatment groups. Liquefaction of thick pleural exudates from rabbits with empyema can be achieved with Varidase but not with streptokinase or urokinase.

Animals↗
PubMed2000

Ankle and foot trauma.

This article reviews the most common foot and ankle injuries that the general radiologist and general orthopedic surgeon are likely to encounter. Fractures and dislocations seen in children and adults are included as well as soft tissue injuries. Ankle fracture classification schemes are discussed briefly. Techniques for advanced imaging with computed tomography (CT) and magnetic resonance (MR) are discussed where appropriate.

Ankle Injuries↗
PubMed2000

Myeloma and lymphoma.

This article reviews current information regarding myeloma, especially multiple myeloma and plasmacytoma as well as primary lymphoma of bone (PLB). The emphasis is on diagnostic imaging, including radiography, computed tomography (CT), magnetic resonance (MR) imaging, and skeletal scintigraphy. Relevant clinical information, histologic findings, treatment, and outcome data are also discussed.

Bone Neoplasms↗
PubMed2000

Antibiotic levels in empyemic pleural fluid.

OBJECTIVE: To determine the degree to which bioactive penicillin, metronidazole, ceftriaxone, clindamycin, vancomycin, and gentamicin penetrate into empyemic pleural fluid using our new rabbit model of empyema. METHODS: An empyema was created via the intrapleural injection of 10(8)()Pasteurella multocida bacteria into the pleural space of New Zealand white rabbits. After an empyema was verified by thoracentesis and pleural fluid analysis, penicillin, 24,000 U/kg; metronidazole, 37 mg/kg; ceftriaxone, 30 mg/kg; clindamycin, 9 mg/kg; vancomycin, 15 mg/kg; or gentamicin, 1 mg/kg, were administered IV. Antibiotic levels in samples of pleural fluid and serum, collected serially for up to 480 min, were then determined using a bioassay. RESULTS: The degree to which the different antibiotics penetrated into the infected pleural space was highly variable. Penicillin penetrated most easily, followed by metronidazole, ceftriaxone, clindamycin, vancomycin, and gentamicin. Of the antibiotics tested, penicillin and metronidazole equilibrated the most rapidly with the infected pleural fluid. Penicillin levels remained elevated in pleural fluid even after serum levels had decreased. CONCLUSIONS: Using this rabbit model of empyema, there was marked variation in the penetration of antibiotics into the empyemic fluid. Although there are species differences between rabbit and human pleura, the variance in degree of penetration of antibiotics into the pleural space should be considered when antibiotics are selected for the treatment of patients with empyema.

Animals↗
PubMed1999

Imaging features of primary lymphoma of bone.

OBJECTIVE: Our objective was to describe the imaging appearances of primary lymphoma of bone, including conventional radiographic, scintigraphic, CT, and MR imaging features. MATERIALS AND METHODS: We retrospectively reviewed 237 pathologically proven cases of primary lymphoma of bone. Evaluation included patient age, sex, lesion location, and pattern of bone destruction. Pathologic type, periosteal reaction, sequestrum, soft-tissue mass, extension across joints, and pathologic fracture were also noted. RESULTS: The study population included 151 males and 86 females (ratio 1.8:1; range, 2-88 years; mean age, 42 years). Common locations were the distal femoral diametaphysis; proximal metadiaphysis of the tibia, femur, and humerus; and femoral mid shaft. Long bones were involved more often than flat bones (71% versus 22%). Common appearances were a lytic (70%) or mixed-density (28%) lesion with most cases showing a permeative or moth-eaten pattern (74%). Periosteal reaction was seen in 58% of the long bones. Sequestra were found in 37 patients (16%). Soft-tissue masses were present in 113 patients (48%). Extension across joints was seen in nine patients (4%). Pathologic fractures occurred in 53 patients (22%). Radionuclide (n = 56), CT (n = 45), and MR (n = 20) features were usually nonspecific. Pathologic types included non-Hodgkin's (n = 223) and Hodgkin's (n = 14) lymphoma. CONCLUSION: Primary lymphoma of bone most often involves the diametaphysis of a major long bone and has an aggressive pattern of lytic bone destruction and associated soft-tissue mass. CT and MR imaging can suggest the diagnosis, particularly when a large soft-tissue mass and abnormal marrow attenuation or signal intensity is seen without extensive cortical destruction.

Adolescent↗
PubMed1998

Extra-articular triplane fracture of the distal tibia: a case report.

The triplane fracture of the distal tibia is anatomically complex. It typically consists of a coronal fracture of the metaphysis, a transverse fracture of the physis, and a sagittal, intra-articular fracture of the epiphysis. We report an unusual variation of the triplane fracture which includes an extra-articular epiphyseal component involving the medial malleolus. This is an important variant to recognize because it does not disrupt the distal tibial articular surface. This lack of articular involvement allows for non-surgical management in contrast to the usual triplane fracture which often requires open reduction and internal fixation.

Adolescent↗
PubMed1998

Classic adamantinoma in a 3-year-old.

Classic adamantinoma of the long bones is a rare, low-grade malignant neoplasm arising most often in the tibia and usually in patients during the second to fifth decades. Although adamantinomas have been described in children, the histologic pattern in this age group is different from that seen in adults and resembles osteofibrous dysplasia. The usual pattern of adamantinoma in children has been termed "differentiated adamantinoma" and follows a benign course. We report a case of adamantinoma in the proximal tibia of a 3-year-old patient. The lesion had abundant epithelial component with formation of keratin pearls, a pattern that has been described only in classic adamantinoma occurring in adults. Since differentiated adamantinomas are essentially benign and classic adamantinomas are low-grade malignancies, the finding of a classic variant at this young age raised important therapeutic and prognostic issues.

Ameloblastoma↗
PubMed1997

Preliminary findings of the international typing study on Clostridium difficile. International Clostridium Difficile Study Group.

Preliminary results of the International Typing Study on Clostridium difficile indicate that there is excellent correlation between the phenotypic methods reliant on cell surface antigens for typing strains and that a larger number of phenotypes and genotypes of C. difficile exists than was previously appreciated by each group of investigators acting independently. Evidence has also emerged that some of the types described by each method are common to all typing methods, indicating that strains of the same type are found in hospitals in the United Kingdom, Belgium, the United States, and Australia.

Bacterial Typing Techniques↗
PubMed1997

Recurrent Clostridium difficile diarrhea: characteristics of and risk factors for patients enrolled in a prospective, randomized, double-blinded trial.

Recurrent Clostridium difficile diarrhea (RCDD) occurs in 20% of patients after they have received standard antibiotic treatment with vancomycin or metronidazole, but the reasons for the recurrences are largely unknown. Patients receiving vancomycin or metronidazole for active C. difficile diarrhea (CDD) were referred to our study centers for treatment and a 2-month follow-up as part of a randomized placebo-controlled trial. Sixty patients had RCDD (median number of episodes, 3.0; range, 2-9 episodes) and 64 were having their first episode of CDD. Patients with RCDD had more-severe abdominal pain and were more likely to have fever but initially responded well to antibiotic therapy. Data on sequential episodes showed no progression in disease severity. Five factors were associated with a higher risk of RCDD: the number of previous CDD episodes, onset of the initial disease in the spring, exposure to additional antibiotics for treatment of other infections, infection with immunoblot type 1 or 2 strains of C. difficile, and female gender. These factors may help to identify patients who are more likely to develop RCDD and require careful medical supervision.

Adult↗
PubMed1997

Identification and characterization of a gene encoding a vertebrate-type carbonic anhydrase in cyanobacteria.

A gene (designated ecaA) encoding a vertebrate-like (alpha-type) carbonic anhydrase (CA) has been isolated from two disparate cyanobacteria, Anabaena sp. strain PCC 7120 and Synechococcus sp. strain PCC 7942. The deduced amino acid sequences correspond to proteins of 29 and 26 kDa, respectively, and revealed significant sequence similarity to human CAI and CAII, as well as Chlamydomonas CAHI, including conservation of most active-site residues identified in the animal enzymes. Structural similarities between the animal and cyanobacterial enzymes extend to the levels of antigenicity, as the Anabaena protein cross-reacts with antisera derived against chicken CAII. Expression of the cyanobacterial ecaA is regulated by CO2 concentration and is highest in cells grown at elevated levels of CO2. Immunogold localization using an antibody derived against the ecaA protein indicated an extracellular location. Preliminary analysis of Synechococcus mutants in which ecaA has been inactivated by insertion of a drug resistance cassette suggests that extracellular carbonic anhydrase plays a role in inorganic-carbon accumulation by maintaining equilibrium levels of CO2 and HCO3- in the periplasm.

Amino Acid Sequence↗
PubMed1997

Femoral sulcus angle measurements.

We sought to determine whether the femoral sulcus angle measurement is consistent on different radiographic projections of the knee. Seventy-four cadaveric knees were radiographed using Merchant, Laurin, and Hughston projections. The measurements of the sulcus angle (mean, 138.6 degrees; SD, 6.9 degrees; and range, 120 degrees to 155 degrees) obtained with the Merchant technique were similar (P = 0.0007) to those obtained with the Hughston (mean, 137.4 degrees; SD, 7.6 degrees; range, 122 degrees to 155 degrees) and Laurin (mean, 141.6 degrees; SD, 6.9 degrees; and range, 125 degrees to 162 degrees) projections. Therefore, we submit that either the Hughston or Laurin view can be used instead of the Merchant view to reliably measure the femoral sulcus angle.

Anthropometry↗
PubMed1996

Supramalleolar fatigue fractures of the tibia.

OBJECTIVE: The objective of this paper is to describe fatigue fractures in the supramalleolar area of the tibia. The spectrum of imaging findings in 14 cases is presented, with emphasis on plain film radiographic findings. DESIGN AND PATIENTS: Fourteen patients with fatigue fractures in the supramalleolar area of the distal tibia were seen in a 6-year period. The 13 men and 1 woman had an age range from 14 to 64 years (mean 30 years). These patients had no underlying conditions that would predispose them to fractures. Sequential plain film radiographs and other special imaging studies (technetium-99m scans and computed tomography) were retrospectively reviewed. RESULTS AND CONCLUSIONS: Initial plain film radiographs showed a horizontal linear band of increased density in only 2 cases, a subtle cortical bulge in 5 cases, a focal "graying" of the cortex in 2 cases, a single layer periosteal reaction in 1 case, and no abnormality in the final 4 cases. Technetium-99m scans were done in 11 cases and showed focal areas of increased uptake in all 11. These areas of increased uptake were vertically orientated in 10. One patient had computed tomography showing cortical thickening around a linear lucency. The spectrum of imaging findings is similar to that seen in fatigue fractures in more common locations. Supramalleolar fatigue fractures should be suspected in patients who have pain in the distal tibia even when initial plain film radiographs are normal. When initial radiographs are normal, technetium-99m scans can confirm the diagnosis.

Adolescent↗