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Biomedical subjects

F Feldman

Publications and source records attributed to F Feldman.

At least 19 recordsLinked to original sources
PubMed2002

Effectiveness of alternative treatments for reducing potential viral contaminants from plasma-derived products.

An issue of great importance and continuing concern with regard to all products derived from human plasma is their safety from potential contaminants in the source material from which they are purified. Since viral contaminants are a major safety consideration with these products, a number of different methods, including dry heating, vapor heating, filtration and nanofiltration, ultraviolet and gamma irradiation, pasteurization, solvent/detergent (S/D) treatment, sodium thiocyanate treatment, and chromatography (immunoaffinity, metal chelation, affinity, and ion exchange), have been developed to remove or inactivate potentially contaminating viruses. Pasteurization and S/D treatment have emerged as the dominant viral inactivation methods. Results summarized in this review demonstrate that pasteurization is the broadest and most rigorous currently available method for removal of potential viral contaminants from plasma-derived products. S/D treatment requires control over a large number of manufacturing parameters and has no ability to inactivate nonlipid-enveloped viruses. Pasteurization requires control over only a small number of manufacturing variables, is easily monitored, and remains effective even if deviations are encountered from specified protein and stabilizer concentrations and temperature. In addition, pasteurization is effective against a wide range of lipid- and nonlipid-enveloped viruses.

Animals↗
PubMed2000

Musculoskeletal radiology: then and now.

Musculoskeletal radiologists, owing to recent advances in imaging technologies and techniques, are playing an increasingly important role in documenting, diagnosing, and treating an increasing variety of bone and soft-tissue lesions. However, improved visualization of anatomic aberrations-"seeing better"-must be paired with "knowing more," on the basis of complete familiarity with all aspects of the biology, physiology, pathophysiology, and static anatomy of the musculoskeletal system. Only with foreknowledge of the latter can the musculoskeletal radiologist fully maximize the benefits of the former.

Biology↗
PubMed1999

Virus reduction in the preparation of intravenous immune globulin: in vitro experiments.

BACKGROUND: While immune globulins for intravenous administration (IGIV) have an excellent record with respect to virus safety, concern regarding these preparations has been raised by reports of transmission of hepatitis C virus (HCV) to patients treated with IGIV and the presence of genetic material for HCV in IGIV preparations. STUDY DESIGN AND METHODS: This in vitro study evaluated the effectiveness of several manufacturing steps, including ethanol precipitation and pasteurization, in reducing HIV and model viruses including encephalomyocarditis (EMC) virus, pseudorabies virus (PRV), bovine viral diarrhea virus (BVDV), Sindbis virus, vaccinia virus, and vesicular stomatitis virus (VSV), as well as HCV RNA, in IGIV. RESULTS: Ethanol precipitation carried out after pasteurization resulted in virus reductions (log10) of >3.97 for HIV, 1.95 for EMC virus, >5.39 for PRV, and 3.52 for BVDV. Pasteurization inactivated EMC virus by 4.52 log10 and resulted in a log10 reduction of >6.54 for HIV, >5.39 for PRV, >6.64 for BVDV, >7.78 for Sindbis virus, >5.84 for vaccinia virus, and >6.99 for VSV. All viruses except EMC virus were reduced below the limit of detection within 6 hours of the beginning of pasteurization. Cohn processing of Fraction II + III paste and the 4.5-percent alcohol precipitation step prior to pasteurization provided additional virus removal. Studies using the polymerase chain reaction technique found that HCV RNA was detectable in the starting fraction of Cohn Fraction II paste, but not in the final IGIV preparation. CONCLUSION: These findings strongly support the viral safety of IGIV prepared by this method and show a significant added measure of virus safety associated with pasteurization of this preparation.

Animals↗
PubMed1999

Fatty infiltration of osseous structures: a long-term complication of oleothorax--case report.

Thoracic imaging of a patient treated for pulmonary tuberculosis with oleothorax therapy before the antibiotic era demonstrated a rare complication. Gross invasion by lipid with subsequent pathologic fracture of the adjacent thoracic vertebra may give rise to symptomatic spinal cord compression. Magnetic resonance imaging is a useful modality for help in diagnosing treatment complications of oleothorax.

Aged↗
PubMed1998

Immunoproliferative small intestinal disease in a 16-year-old boy presenting as severe malabsorption with excellent response to tetracycline treatment.

Immunoproliferative small intestinal disease (IPSID) is a rare lympho-proliferative disorder of the upper small intestine. It is considered a special form of MALT lymphoma with propensity to malignant transformation. This disorder is rare in pediatric literature. We report a case of IPSID in a 16-year-old boy with low-grade malignant transformation, presenting as severe malnutrition and a possible association with Helicobacter pylori. The patient responded well to an extended treatment with tetracycline and eradication of H. pylori.

Adolescent↗
PubMed1998

Gradient-echo versus fat-suppressed fast spin-echo MR imaging of rotator cuff tears.

OBJECTIVE: The purpose of this study is to compare fat-suppressed T2-weighted fast spin-echo sequences with T2-weighted multiplanar gradient-echo sequences in revealing rotator cuff disorders. MATERIALS AND METHODS: Oblique coronal fat-suppressed fast spin-echo images and gradient-echo images of 39 patients who underwent surgery of the shoulder were retrospectively reviewed. Images from the two techniques were reviewed separately. Each set of images was interpreted twice by four musculoskeletal radiologists independently and without knowledge of the surgical findings. Sensitivity and specificity for both sequences were determined. The kappa statistic was used to calculate intraobserver and interobserver agreement of interpretations. RESULTS: For detecting any tear, the sensitivity of the four readers was 71-96% using fast spin-echo and 58-100% using gradient-echo imaging. Confidence intervals showed no difference between the two sequences. Sensitivity of detecting full-thickness tears was 83-100% for both sequences. Interobserver agreement was good. CONCLUSION: T2-weighted gradient-echo and fat-suppressed T2-weighted fast spin-echo sequences depict rotator cuff tears equally well and take less time to acquire than conventional dual-echo spin-echo sequences.

Female↗
PubMed1998

Relationship of the meniscofemoral ligaments of the knee to lateral meniscus tears: magnetic resonance imaging evaluation.

This study sought to determine if the presence or absence of meniscofemoral ligaments exerts an influence on the prevalence of tears of the lateral meniscus. We reviewed the sagittal and coronal magnetic resonance images of 173 knees for lateral meniscus tears and the presence of the meniscofemoral ligaments. One or both meniscofemoral ligaments were present in 142 of 173 knees (82%). Fifty-four knees had lateral meniscus tears, 27 of which involved the posterior horn. Thirty-three percent of knees with meniscofemoral ligaments had a lateral meniscus tear, and 23% of knees without meniscofemoral ligaments had a lateral meniscus tear (no significant difference). We found no association between the presence of the meniscofemoral ligaments and tears of the lateral meniscus. Our study questions the importance of preserving or reconstructing these ligaments in instances of meniscal transplantation.

Adolescent↗
PubMed1997

Meniscal position on routine MR imaging of the knee.

OBJECTIVE: To determine the prevalence of meniscal protrusion (i.e. location of the outer edge of a meniscus beyond the tibial articular surface), and to determine its relationship with internal derangement, joint effusion, and degenerative arthropathy. DESIGN AND PATIENTS: Sagittal and coronal MR images of 111 abnormal and 46 normal knees were evaluated for the presence of meniscal protrusion. We set 25% as the minimum amount of displacement considered abnormal because this was the smallest amount of displacement we could confidently discern. Presence of meniscal tear, anterior cruciate ligament (ACL) injury, joint effusion, or osteophytosis was also recorded. RESULTS AND CONCLUSION: Normal examinations demonstrated protrusion of the medial meniscus in 6.5% of sagittal images and 15% of coronal images, and of the lateral meniscus in 2% and 13%, respectively. Fisher's exact test demonstrated a statistically significant difference between the normal and abnormal groups for the medial meniscus on both sagittal (P < 0.0001) and coronal (P = 0.01) images, but not for the lateral meniscus in either plane (P > 0.2). A protruding medial meniscus was associated with effusion and osteophytosis (P < 0.05) but not with meniscal or ACL tear (P > 0.1). Posterior protrusion of the lateral meniscus was only associated with ACL injury (P < 0.0001); protruding anterior horns and bodies of lateral menisci were not associated with any of the four abnormalities. It is concluded that the medial meniscus may occasionally protrude more than 25% of its width, but protrusion is more often due to effusion and osteophytes. Protrusion of the posterior horn of the lateral meniscus is associated with ACL insufficiency, while protrusion of the body and anterior horn of the lateral meniscus is a normal variant.

Adolescent↗
PubMed1997

Fat-suppressed MRI of musculoskeletal infection: fast T2-weighted techniques versus gadolinium-enhanced T1-weighted images.

PURPOSE: To investigate gadolinium's role in imaging musculoskeletal infection by comparing the conspicuity and extent of inflammatory changes demonstrated on gadolinium-enhanced fat-suppressed T1-weighted images versus fat-suppressed fast T2-weighted sequences. DESIGN: Eighteen patients with infection were imaged in a 1.5-T unit, using frequency-selective and/or inversion recovery fat-suppressed fast T2-weighted images (T2WI) and gadolinium-enhanced frequency-selective fat-suppressed T1-weighted images (T1WI). Thirty-four imaging planes with both a fat-suppressed gadolinium-enhanced T1-weighted sequence and a fat-suppressed T2-weighted sequence were obtained. Comparison of the extent and conspicuity of signal intensity changes was made for both bone and soft tissue in each plane. RESULTS: In bone, inflammatory change was equal in extent and conspicuity on fat-suppressed T2WI and fat-suppressed T1WI with gadolinium in 19 planes, more extensive or conspicuous on T2WI in three planes, and less so on T2WI in two planes. Marrow was normal on all three sequences in 10 cases. In soft tissue, inflammatory change was seen equally well in 20 instances, more extensively or conspicuously on the T2WI in 11 instances, and less so on T2WI in 2 instances. One case had no soft tissue involvement on any of the sequences. Five abscesses and three joint effusions were present, all more conspicuously delineated from surrounding inflammatory change on the fat-saturated T1WI with gadolinium. The average imaging time for the fat-saturated T1WI with gadolinium was 6.75 min, while that of the T2-weighted sequences was 5.75 min. CONCLUSION: Routine use of gadolinium is not warranted. Instead, gadolinium should be reserved for clinically suspected infection in or around a joint, and in cases refractory to medical or surgical treatment due to possible abscess formation.

Adipose Tissue↗
PubMed1997

Pseudodefect of the talar dome: an anatomic pitfall of ankle MR imaging.

PURPOSE: To identify a normal groove in the posterior aspect of the talus as a potential pitfall in interpretation of ankle magnetic resonance (MR) images. MATERIALS AND METHODS: In 40 patients, T1-weighted spin-echo and T2-weighted fast spin-echo sagittal MR images were retrospectively reviewed from 47 consecutive routine ankle examinations. The patients were referred for evaluation of ligament and tendon abnormalities, such as tendinitis and tear, and suspected osseous and osteochondral injuries. Images were assessed for the presence of an erosion-like defect in the posterior aspect of the talar dome. Radiographs were available in 13 cases. Sagittal T1-weighted spin-echo sequences were also performed in 14 embalmed cadaveric ankles, followed by sectioning and dissection of three specimens. RESULTS: A defect was seen in 45 of 47 ankle MR imaging examinations. Radiographs did not show the defect. All 14 cadaveric ankles demonstrated the defect at MR imaging. At anatomic dissection, the defect was a normal groove for the passage of the posterior talofibular ligament. CONCLUSION: The pseudodefect of the talar dome is a normal groove for the posterior talofibular ligament and should not be misinterpreted as an articular erosion or osteochondral defect.

Adolescent↗
PubMed1997

Tumor-induced osteomalacia: clinical and basic studies.

A patient with classic clinical and biochemical features of tumor-induced osteomalacia (hypophosphatemia, phosphaturia, and undetectable serum concentrations of 1,25-dihydroxyvitamin D [1,25(OH)2D]) was studied before and after resection of a benign extraskeletal chondroma from the plantar surface of the foot. Presurgical laboratory evaluation was notable for normal serum concentrations of calcium, intact parathyroid hormone (PTH), parathyroid hormone-related protein (PTHrP), and osteocalcin, increased serum alkaline phosphate activity, and frankly elevated urinary cyclic adenosine monophosphate (cAMP) and pyridinium cross-link excretion. Quantitative histomorphometry showed severe osteomalacia and deep erosions of the cancellous surface by active osteoclasts. After resection, serum 1,25(OH)2D normalized within 24 h, while renal tubular phosphorus reabsorption and serum phosphorus did not normalized until days 2 and 3, respectively; serum Ca declined slightly, and serum intact PTH, osteocalcin, and urinary pyridinium cross-link excretion increased dramatically. Urinary cAMP excretion declined immediately after resection and then began to increase concomitant with the increase in serum intact PTH. A second bone biopsy taken 3 months after resection demonstrated complete resolution of the osteomalacia, increased mineral apposition rate (1.09 mu/day), resorption surface (9.2%), mineralizing surface (71%), and bone formation rate (0.83 mm3/mm2/day), and marked decrease in cancellous bone volume (13.1%) and trabecular connectivity compared with first biopsy. Tumor extracts did not affect phosphate transport in renal epithelial cell lines or 1 alpha-hydroxylase activity in a myelomonocytic cell line. The patient's course suggests that the normal 1,25(OH)2D and phosphorus metabolism is due to a tumor product that may be acting via stimulation of adenylate activity. Increased bone resorption prior to surgical resection suggests that the tumor may also produce an osteoclast activator. The rise in resorption surface and pyridinium cross-link excretion, increase in serum osteocalcin and bone mineralization, normalization of osteoid width, and fall in cancellous bone volume after resection are consistent with healing of osteomalacia by rapid remodeling.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1996

MR imaging of Baker cysts: association with internal derangement, effusion, and degenerative arthropathy.

PURPOSE: To determine the prevalence of Baker cyst in a general orthopedic population and its association with effusion, internal derangement, and degenerative arthropathy. MATERIALS AND METHODS: Reports of 400 knee magnetic resonance imaging examinations were reviewed. Presence of Baker cyst, effusion, internal derangement (meniscal and/or anterior cruciate ligament tears), medial collateral ligament injury, and degenerative arthropathy was recorded. Uni- and multivariate logistic regressions were used to evaluate associations between Baker cyst and these conditions. Probabilities of having a Baker cyst given these conditions were also calculated. RESULTS: No association was found between Baker cyst and anterior cruciate ligament tear or medial collateral ligament injury. There were significant associations (P < .001) with effusion, meniscal tear, and degenerative arthropathy. There were also significant associations (P < .01) for effusion, meniscal tear, and degenerative arthropathy, independent of one another. Probability of having Baker cyst given the presence of any one variable was .08-.10; any two variables, .19-.21; and all three variables, .38. CONCLUSION: The association between Baker cyst and joint effusion was confirmed. A relationship with meniscal tear and degenerative joint disease independent of effusion was also demonstrated. The probability of having a Baker cyst increases as the number of these associated conditions increases.

Anterior Cruciate Ligament Injuries↗