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Biomedical subjects

T J O'Brien

Publications and source records attributed to T J O'Brien.

At least 91 records · Page 5Linked to original sources

Rhinocerebral mucormycosis presenting as periorbital cellulitis with blindness: report of 2 cases.

Two cases of rhinocerebral mucormycosis in elderly, non-ketotic diabetics who were initially diagnosed and treated for bacterial periorbital cellulitis are reported. Both presented with a short history of periorbital pain and swelling followed rapidly by complete ophthalmoplegia and blindness. By the time of correct diagnosis, both cases were advanced with lower cranial nerve involvement, CT evidence of ophthalmic artery and cavernous sinus thrombosis and, in one, internal carotid artery invasion (demonstrated on MR angiography) with resultant cerebral infarction. One patient was treated with intravenous amphotericin B but died within a few days. The second patient had aggressive surgical resection and survived with significant residual morbidity. These cases illustrate that mucormycosis should be excluded in any diabetic patient presenting with orbital cellulitis, especially when there is early visual loss. Early aggressive treatment with surgery and antifungal agents is often successful whereas the outcome is almost universally fatal when the diagnosis is delayed.

Aged↗

Characterization of CA 125 synthesized by the human epithelial amnion WISH cell line.

CA 125 has been established as an important tumor marker for monitoring patients diagnosed with nonmucinous ovarian cystadenocarcinoma although it has also been shown to be expressed by other carcinomas, normal epithelial tissues, and fetal tissues. Current evidence implicates a role for CA 125 during early fetal development. The human epithelial amnion WISH cell line is a known secretor of CA 125. WISH cells have been investigated as a model system to characterize the structure of cell-associated and secreted CA 125 of fetal origin. CA 125 secretion was maximal in confluent monolayers of WISH cells where it averaged 2,081 units/ml/24 h. Secretion ranges from 600 to 900 units/10(6) cells/24 h. [35S]-Methionine-labelled CA 125 can be detected by 4 h and reached maximal levels of radioactive incorporation in tissue culture medium by 12 h when analyzed by immunoprecipitation with the M11 anti-CA 125 monoclonal antibody and SDS-PAGE, followed by autoradiography. Both cycloheximide and actinomycin D inhibited CA 125 synthesis. CA 125 was demonstrated to incorporate [3H]-galactose but the level of radioactive incorporation was greatly reduced when WISH cells were incubated in the presence of phenyl N-acetyl-alpha-D-galactosaminide (an inhibitor of O-linked glycosylation) or monensin (an inhibitor of intracellular protein transport within the Golgi complex). Treatment of WISH cells with tunicamycin (an inhibitor of N-linked glycosylation) only slightly decreased label incorporation.

Amnion↗

Serial transvaginal ultrasound scans and beta-human chorionic gonadotropin levels in early singleton and multiple pregnancies.

OBJECTIVE: To determine if serum beta-hCG levels are higher in multiple gestation than in singleton pregnancy at the time of intrauterine sac visualization and the first appearance of fetal heart activity as documented by serial transvaginal ultrasound (US). DESIGN: Prospective analysis of serial transvaginal US findings in 19 pregnancies correlated with serum hCG levels during early gestation. SETTING: Reproductive endocrinology division of the University of Arkansas for Medical Sciences, Little Rock, Arkansas. PATIENTS: Nineteen infertility patients were studied after conceiving. Thirteen underwent IVF or GIFT, 4 received hMG therapy, 1 was treated with clomiphene citrate, and 1 pregnancy followed spontaneous ovulation. INTERVENTIONS: Transvaginal US and hCG levels were obtained every Monday, Wednesday, and Friday from 20 to 22 days after ovulation until the appearance of fetal heart activity. RESULTS: Initial sac visualization occurred at lower serum hCG levels in singleton versus multiple pregnancies (2,180 +/- 1,170 versus 7,028 +/- 4,280 mIU/mL, mean +/- SD). Sacs were always seen when the serum hCG level (mIU/mL) was > or = 1,161 in singleton, 1,556 in twin, 3,372 in triplet, and 9,399 in quadruplet pregnancies. CONCLUSION: Failure to observe an intrauterine sac by transvaginal US in the presence of serum hCG levels in the 1,000 to 2,000 mIU/mL range is not pathognomonic for an ectopic gestation. Clinical symptomatology, risk of multiple pregnancies, and gestational age must also be considered.

Analysis of Variance↗

Identification and characterization of a second major peanut allergen, Ara h II, with use of the sera of patients with atopic dermatitis and positive peanut challenge.

Peanuts are frequently a cause of food hypersensitivity reactions in children. Serum from nine patients with atopic dermatitis and a positive double-blind, placebo-controlled, food challenge to peanut were used in the process of identification and purification of the peanut allergens. Identification of a second major peanut allergen was accomplished with use of various biochemical and molecular techniques. Anion exchange chromatography of the crude peanut extract produced several fractions that bound IgE from the serum of the patient pool with positive challenges. By measuring antipeanut specific IgE and by IgE-specific immunoblotting we have identified an allergic component that has two closely migrating bands with a mean molecular weight of 17 kd. Two-dimensional gel electrophoresis of this fraction revealed it to have a mean isoelectric point of 5.2. According to allergen nomenclature of the IUIS Subcommittee for Allergen Nomenclature this allergen is designated, Ara h II (Arachis hypogaea).

2S Albumins, Plant↗

Multifocal osteonecrosis after short-term high-dose corticosteroid therapy. A case report.

Osteonecrosis is a common sequela of long-term steroid therapy. This paper presents the only case of multifocal osteonecrosis to occur after a short-term course of methylprednisolone for treatment of septic shock. Two years after receiving a two-week course of corticosteroid treatment, the patient developed pain in his right and left shoulders and left hip. Roentgenograms and magnetic resonance imaging revealed changes consistent with osteonecrosis of both humeral heads and the femoral head. The patient failed to respond to conservative treatment and eventually was treated with bipolar hip replacement.

Adult↗

Alteration in age-specific risks for chromosomal trisomy by maternal serum alpha-fetoprotein and human chorionic gonadotropin screening.

Maternal serum screening for alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) increases the detection rate of Down's syndrome (DS) pregnancies. To estimate the risk of a DS pregnancy for a particular woman, Wald et al. combine a trivariate function of AFP, hCG, and unconjugated oestriol with age-specific risk. Calculation of independent likelihood ratios (LRs) for AFP and hCG has allowed us to examine the predictive value of each test alone and the combination. AFP and hCG were measured in stored serum samples from 672 normal, 8 trisomy 21 (DS), 9 trisomy 18, and 2 trisomy 13 pregnancies. AFP and hCG multiples of the median (MOM) were calculated for each sample. The LRs for AFP MOM and hCG MOM were calculated and combined with age-specific risk. Of eight DS pregnancies, six had increased risk based on age and AFP. Addition of hCG detected two additional DS pregnancies. Of nine trisomy 18 pregnancies, four (44 per cent) had hCG MOM under 0.25. Three out of nine would have been classified as high risk by AFP, but none by combined AFP and hCG. Amniocentesis would have been recommended in 74 per cent of aneuploid pregnancies if both age and serum screening were used. Abandonment of amniocentesis based on age alone would have excluded two abnormal pregnancies from detection. Screening programmes should note that combined risk figures are specific for DS and do not include other trisomies. Detection of other trisomies requires inclusion of low hCG level as a discriminator and continuation of age-based testing.

Age Factors↗

New monoclonal antibodies identify the glycoprotein carrying the CA 125 epitope.

CA 125 is an antigenic determinant located on the surface of ovarian carcinoma cells and elevated in the serum of greater than 90% of patients with carcinoma. The antigen, derived from the ovarian epithelium, has been described as a mucinlike glycoprotein greater than 200 kd. To date little is known of the metabolic regulation or expression of this antigen in either normal or neoplastic tissues. New monoclonal antibodies that we describe here recognize both unique and similar epitopes to OC 125. These reagents may allow for a more complete definition of the structure and expression of the CA 125 complex. These antibodies recognize high-molecular weight (greater than 200 kd) subspecies and a lower-molecular-weight (68 kd) subspecies of the antigen and identify it in the cytoplasm and the extracellular matrix of CA 125-producing cells.

Animals↗

Tears of the glenoid labrum: MR imaging of 88 arthroscopically confirmed cases.

Two hundred eighty-one patients underwent magnetic resonance (MR) imaging of the shoulder over a 2-year period. Eighty-eight patients underwent arthroscopic surgery, and their surgical results were correlated with the findings at MR imaging. MR imaging enabled accurate prediction of anterior labral tears, with a sensitivity of 95%, a specificity of 86%, and an accuracy of 92%. MR imaging was less effective in the prediction of tears of the superior labrum, with a sensitivity of 75%, a specificity of 99%, and an accuracy of 95%. These two categories accounted for the majority of the surgically correctable disease. MR imaging was found to be unreliable in the prediction of posterior (sensitivity, 7.7%) or inferior (sensitivity, 40%) labral tears, isolated cases of which occurred in only two (2%) of those undergoing surgery. MR imaging proved to be a highly accurate, noninvasive technique for the clinical evaluation of shoulder instability.

Adolescent↗

Cloning of a mu-class glutathione S-transferase complementary DNA and characterization of its glucocorticoid inducibility in a smooth muscle tumor cell line.

A cDNA (designated hGSTYBX) encompassing the complete coding sequence of a hamster mu-class glutathione S-transferase (GST) subunit was cloned from a lambda ZAP library constructed with mRNA isolated from triamcinolone acetonide-treated smooth muscle tumor cells (DDT1 MF-2). Analysis of its nucleotide and deduced amino acid sequences demonstrated highest homology to the rat mu-class GST YB2 subunit. In proliferating subconfluent cells, in which constitutive expression of hGSTYBX mRNA was undetectable, glucocorticoid treatment induced hGSTYBX expression after a time lag of 3 h, and maximal induction occurred at 10 h. Nuclear run-on analysis showed that glucocorticoid induction resulted at least in part from an increased rate of transcription. Simultaneous treatment with glucocorticoid and cycloheximide prevented glucocorticoid induction, but had little effect on basal expression in confluent cells. In contrast, cycloheximide treatment 3 h after glucocorticoid treatment resulted in nearly full induction. These results taken together suggest that hGSTYBX induction may be a secondary glucocorticoid response.

Amino Acid Sequence↗

Distribution of CA 125 in embryonic tissues and adult derivatives of the fetal periderm.

New murine monoclonal antibodies to a partially purified CA 125 antigen were developed and identified as M 2 and M 11. With immunohistochemical techniques, these new antibodies and OC 125 antibody were used to search for CA 125 in embryonic tissues and adult apocrine sweat glands and mammary glands. The embryonic skin, the periderm, expressed CA 125 antigen and its adult derivatives, the mammary glands and apocrine sweat glands, expressed CA 125 while in the active state of secretion. In a 6-week-old formalin-fixed and paraffin-embedded ectopic embryo specimen, antibodies M 2 and M 11 recognized CA 125 in the periderm, the notochord, the myocardium, the pericardium, the gastroenteric tract, enteric duct remnants in the umbilical cord (vitelline and allantoic ducts), the mesonephric duct, and the amnion. OC 125 staining of these formalin-fixed specimens was either very faint or absent. In a formalin-fixed and paraffin-embedded specimen of apocrine sweat glands from the axilla, antibodies M 2 and M 11 detected CA 125 antigen intracellularly in the secretory cells. Again no staining was observed with OC 125 antibody. In a frozen and acetone-fixed specimen of lactating mammary glands, antibodies M 2 and OC 125 detected CA 125 antigen intraductally. Colostrum and milk collected from 25 mothers at various stages post partum had mean CA 125 levels of 34,213 U/ml in colostrum, 1469 U/ml at 3 to 7 days, and 105 U/ml at 5 to 26 weeks.

Amnion↗

Expression of the ras oncogene in gynecologic tumors.

Control of oncogene expression has been shown to be a coordinated regulatory mechanism in normal growth and development. Overt expression of these genes also has been noted in transformed or neoplastic cell types. The ras family of oncogenes has been shown to be particularly evident among genes expressed in malignant tissues. We provide evidence, using ribonucleic acid dot analysis and Western blot analysis of gynecologic tumor extracts, that ras expression may be a common occurrence in these malignancies. Furthermore, the ras-related peptides can be detected in sera of some patients with tumors.

Electrophoresis, Polyacrylamide Gel↗