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Biomedical subjects

S McCarthy

Publications and source records attributed to S McCarthy.

At least 73 records · Page 4Linked to original sources
PubMed1993

Monostotic fibrous dysplasia of the orbit: an unusual lacrimal fossa mass.

A case of monostotic fibrous dysplasia involving the orbit, presenting with a short history of painful, progressive proptosis and a lacrimal fossa mass is reported. There were no clinical or radiological clues to the diagnosis which was made on frozen section at the time of open surgical biopsy. The features of orbital fibrous dysplasia are reviewed and a possible mechanism for this rare clinical presentation of fibrous dysplasia is discussed.

Adult↗
PubMed1993

Malignant transformation of osteoblastoma: study using image analysis microdensitometry.

AIM: To determine if the malignant transformation, as perceived histologically, in a case of osteoblastoma from the right femur, was also expressed as a quantitative change in nuclear DNA during tumour progression over five months. METHODS: Nuclear DNA microdensitometry by computer image analysis was used to acquire relative DNA distribution patterns. Tissue had been removed on four separate occasions from a lesion in the right femur of an 18 year old man. Retrospective DNA analysis was performed on formalin fixed, paraffin wax-embedded tissue. RESULTS: The DNA profile of the initial biopsy specimen, which was histologically diagnosed as osteoblastoma, was euploid with a near diploid (2c) modal DNA. The second biopsy specimen taken one month later also resembled osteoblastoma but showed an aneuploid DNA profile with a diploid modal DNA and some nuclei with ploidy greater than 5c. The third biopsy specimen taken four months later showed histological evidence of osteosarcoma and a near pentaploid (5c) modal DNA with large number of nuclei exceeding 5c. CONCLUSIONS: DNA microdensitometry confirmed the initial and final diagnosis. The technique also seems to be capable of detecting aneuploidy before malignancy is morphologically evident.

Adolescent↗
PubMed1993

USDA's Plant Genome Research Program.

Biotechnology will provide U.S. farmers with another green revolution. The United States Department of Agriculture has put together the Plant Genome Research Program as a coordinated multi-agency effort within the department to help develop the "new agriculture." The Cooperative State Research Service is managing the program's competitive research grants. Research topics include high- and low-resolution chromosomal maps; the isolation and transfer of economically important genes; and new technology developments. The Agricultural Research Service is the lead agency for the Plant Genome Research Program and coordinates data collection and information management resources for the program. Five species groups are collaborating in the database development effort for the program by defining the user needs for their species and collecting and evaluating their species data for the database. A central database for the Plant Genome Research Program is under development at the National Agricultural Library (NAL) and ultimately will contain data for as many as seventy-one different plant species. NAL will provide user access via Internet, dial-up modem, and, at a later date, a CD-ROM product.

Chromosome Mapping↗
PubMed1992

Pelvic phased array coil: image quality assessment for spin-echo MR imaging.

The NMR phased array coil (PA) provides improved signal-to-noise ratio (SNR) over that available with the body coil. We evaluated image quality obtained with a pelvic PA compared to that obtained with the body coil for spin-echo imaging. Thirty-three women undergoing clinical pelvic MRI were imaged with the body coil followed by imaging with the PA with the same field-of-view (FOV) in 11 patients, and with a small FOV in 23 patients. Image quality was assessed independently by two radiologists. In individual cases there was significant improvement in image quality with the PA, however the expected marked improvement in image quality was not consistently found. Two factors which may limit image quality are increased motion artifact and nonuniformity of signal with distance from the coils. Significant improvements in image quality may occur with improved techniques to decrease motion artifact.

Adult↗
PubMed1992

Effect of prone versus supine patient positioning on pelvic magnetic resonance image quality.

RATIONALE AND OBJECTIVES: Magnetic resonance imaging (MRI) of the pelvis in the prone position has been proposed as a means of reducing motion-related image blurring. The authors performed a randomized controlled trial to determine if patient positioning affects image quality. METHODS: All women undergoing pelvic MRI during a 7-month period, who could lie both prone and supine, were randomized to the supine or prone position. The quality of axial T2-weighted spin-echo images was rated by two radiologists using a 1-to-4 scale (1 = marked blurring to 4 = sharp definition of pelvic structures). RESULTS: Of 78 eligible women, 61 were randomized. Two patients could not complete the examination. The mean image quality rating of 2.8 for the 32 patients imaged prone was not significantly different from the mean rating of 2.9 for the 27 patients imaged supine (P = .5, Mann-Whitney U test). CONCLUSION: Patient positioning did not significantly affect pelvic MRI quality. The choice of patient position should be based on other considerations, such as patient comfort or ease of patient positioning.

Adult↗
PubMed1992

Can MR imaging effectively replace diagnostic arthroscopy?

A study was performed to determine whether magnetic resonance (MR) imaging is cost-effective and reduces the need for diagnostic arthroscopy of the knee. During a 9-month period, 103 consecutive patients with knee injury that justified diagnostic arthroscopy underwent MR imaging. The MR images were interpreted by means of consensus of three radiologists and reviewed with the referring sports medicine orthopedists. After the examination, 44 patients (42.7%) underwent immediate arthroscopy. The 59 other patients (57.3%) did not undergo arthroscopy; follow-up was performed in 55 of these 59 patients (93%) at a mean of 22 months. The outcome was successful in 49 of 55 patients (89%); 40 patients had normal function and no limitation in activity, six patients with chronic injury of the anterior cruciate ligament underwent reconstruction, and three patients underwent arthroscopy with negative findings. Without the use of MR imaging, all patients in this study would have undergone diagnostic arthroscopy. Because of the diagnoses based on MR images, 53 patients (51.4%) avoided a potentially unnecessary diagnostic arthroscopy, and, as a result, the net savings was $103,700 in the 103 patients.

Adolescent↗
PubMed1992

Fast spin-echo MR imaging of the female pelvis. Part I. Use of a whole-volume coil.

In this prospective study, axial and sagittal magnetic resonance (MR) images were obtained with T2-weighted conventional spin-echo (CSE) and fast spin-echo (FSE) sequences in 34 consecutive female patients who underwent clinical pelvic MR examination at 1.5 T. The MR images from each patient were compared side by side, blindly and independently, by two radiologists experienced in MR imaging who used a standardized score sheet for anatomic and pathologic findings. The FSE sequences were rated superior significantly more often than the CSE sequences in most categories of findings (P less than .05), including overall image quality and reduction of motion artifact. The examination time for the FSE sequences was 1 minute 46 seconds versus an examination time of 9 minutes 14 seconds for the CSE sequences. (Both CSE and FSE sequences provided 18 sections.) It is concluded that the FSE sequence provides T2-weighted anatomic and pathologic information superior to that provided by the CSE sequence and requires substantially less imaging time.

Adolescent↗
PubMed1992

Multicoil high-resolution fast spin-echo MR imaging of the female pelvis.

A fast spin-echo pulse sequence was combined with multiple surface coils used simultaneously in the form of a "multicoil" in magnetic resonance imaging studies of the female pelvis. This combination allowed maximal resolution with maintenance of the signal-to-noise ratio (S/N) at an acceptable level, and the S/N with the multicoil system was substantially better than that achieved with a body coil. Excellent image quality and demonstration of anatomic detail were afforded by use of this technique.

Adolescent↗
PubMed1992

Submucosal uterine leiomyomas: diagnosis of prolapse into the cervix and vagina based on MR imaging.

OBJECTIVE: We describe the MR appearance, signs and symptoms, and pathologic findings in five patients with submucosal leiomyomas that prolapsed into the cervical or vaginal canal. SUBJECTS AND METHODS: During the past 3 years, five women aged 33-53 years (mean, 43 years) were identified prospectively at MR imaging as having prolapsing uterine leiomyomas. The diagnosis was confirmed by surgical pathology. MR imaging was performed on a 1.5-T unit, using both T1- and T2-weighted spin-echo or fast spin-echo sequences. The images were analyzed for signal intensity, presence of a stalk, and caudal extent of the prolapsed leiomyoma. RESULTS: These leiomyomas, the presence of prolapse, and the caudal extent of prolapse were detected prospectively on MR images in all five cases. Prospective localization of the stalk in two cases aided subsequent hysteroscopic resection. MR imaging correctly indicated the presence of hemorrhage in one, degeneration in a second, and the absence of these complications in two others. In the fifth case, a hemorrhagic focus in the distal tip of the leiomyoma was not detected on MR images obtained 3 days before surgery. CONCLUSION: MR imaging is useful for the diagnosis and characterization of uterine leiomyomas that have prolapsed into the cervical or vaginal canal.

Adult↗
PubMed1992

Nursing home employment: the nurse's aide's perspective.

1. Nurse's aides are an essential component of quality nursing home care. This study explores some of their opinions about their employment. 2. Despite the many individual demographic differences, the findings of this study indicate that nurse's aides as a group hold many similar opinions about what they like and dislike about their jobs. 3. Multiple factors affect the attitudes of nurse's aides toward their employment. 4. The findings of this study indicate that attachment to others (residents, co-workers) and a sense of personal gratification in the work itself are major themes associated with both retention and morale of nurse's aides.

Humans↗
PubMed1992

Physics of magnetic resonance.

The magnetic resonance technique has had a major impact on medical imaging. Unlike x-ray imaging techniques, magnetic resonance imaging (MRI) does not use ionizing radiation. It uses a strong external magnetic field provided by a superconducting magnet and radiofrequency radiation to generate tomographic images in any plane. The contrast between different tissues is based upon multiple factors that can be explained in terms of the magnetic properties of matter. The tissue contrast provided by MRI is superior to that of any other imaging technique. This paper provides a brief introduction to the underlying physical principles of clinical MRI. The basic concepts of T1, T2 and image generation are discussed for spin echo pulse sequences.

Forecasting↗
PubMed1992

A monocyte/macrophage antigen recognized by the four antibodies GHI/61, Ber-MAC3, Ki-M8 and SM4.

A new monoclonal antibody, GHI/61, which labels the majority of monocytes and tissue macrophages is described. This antibody recognizes an intracellular antigen of 130,000 MW (reduced) and 110,000 MW (unreduced). Using biochemical, flow cytometry and immunocytochemical studies antibody GHI/61 was shown to recognize the same antigen as the previously described antibodies Ber-MAC3, Ki-M8 and SM4. On the basis of the results obtained, antibodies GHI/61, SM4, Ber-MAC3 and Ki-M8 should form a new CD group at the next Leucocyte Typing Workshop. Since the antigen recognized by the antibody GHI/61 is relatively easy to purify, the sequencing and the isolation of the gene encoding this protein should be possible.

Antibodies, Monoclonal↗
PubMed1992

Magnetic resonance imaging of the normal female pelvis.

MR imaging has emerged as an important modality in the evaluation of the female pelvis as a result of the detailed demonstration of normal anatomy. Tissue planes within the uterus, cervix, vagina, and ovaries are clearly delineated, thus enabling a better understanding of normal anatomy and, therefore, pathology.

Female↗
PubMed1991

Metabolism of dichlorobenzenes in organ cultured liver slices.

A novel in vitro system was used to evaluate tissue specific toxicity. This system utilizes precision cut organ slices in dynamic organ culture and is viable for up to 24 hrs. The three isomers of dichlorobenzene were added to liver slices prepared from Sprague Dawley rats or human donors. The precursor dichlorobenzenes were radiolabelled and metabolites were separated by classes (i.e. glucuronides, sulfates and glutathione and cysteine conjugates). Covalent Binding of the dichlorobenzenes was also determined after extensive extraction of the tissue. The total amount of metabolism of the dichlorobenzenes varied depending on the isomer and the type of tissue. For example, the Sprague-Dawley rat liver slices metabolized 1,2-DCB and 1,3-DCB at approximately the same rate while 1,4-DCB was metabolized at a slower rate. This metabolism profile was also seen in the majority of the adult human liver slices. However, the fetal human slices showed that 1,4-DCB was metabolized to a greater extent than 1,3-DCB or 1,2-DCB while 1,3-DCB was metabolized at a faster rate than 1,2-DCB. Our results show that liver slices in organ culture are a suitable system for species comparisons and of structure/activity relationships in xenobiotic metabolism with an emphasis on the fate of reactive intermediates. In addition, this system is suitable for evaluation of hepatotoxic potency.

Animals↗