Biomedical subjects

T J O'Brien

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

At least 163 records · Page 9Linked to original sources

PubMedDate not supplied

Maternal serum human chorionic gonadotropin as a marker for the delivery of low-birth-weight infants in women with unexplained elevations in maternal serum alpha-fetoprotein.

We wished to ascertain whether the measurement of maternal serum human chorionic gonadotropin (MShCG) in the serum of pregnant women with unexplained elevations of maternal serum alpha-fetoprotein (MSAFP) would more precisely define those women at risk of adverse pregnancy outcomes. MShCG was measured in samples of serum obtained from women in the second trimester of pregnancy who had elevated MSAFP, normal Level II ultrasounds, and normal fetal karyotypes. Based on the characteristics of a receiver-operator curve for MShCG and birth weight, patients were divided into two groups and pregnancy outcomes were compared. Pregnant women with an unexplained elevation in MSAFP, who also had an abnormal MShCG (< or = 0.5 MoM > or = 2.5) were at significantly greater risk of delivering a low-birth-weight infant compared to women with a normal MShCG (43% and 15%, respectively; P = 0.013). They were also more likely to deliver a preterm infant (48% and 11.9%), respectively; P = 0.001). In the prediction of low birth weight, an abnormal MShCG had a sensitivity of 50%, a specificity of 81%, and a positive predictive value of 43%; in the detection of preterm delivery the values were 59%, 88%, and 48%, respectively. These findings suggest that in pregnant women with a second trimester unexplained elevation in MSAFP, abnormal MShCG levels may identify a group of women at high risk of preterm delivery or delivery of a low-birth-weight infant.

Adolescent↗

PubMedDate not supplied

Conditioning in human opiate addicts.

Eight volunteers maintained on daily methadone participated in a classical conditioning procedure to determine which if any of the elements of narcotic withdrawal could be conditioned; The unconditioned stimulus was the injection of a small dose of naloxone. The unconditioned response was a brief precipitated withdrawal syndrome. The conditioning stimulus was a tone, odor, and injection of saline. Conditioning was successful in the pilot study in 5 of 8 subjects. The conditioned response consisted of tearing, yawning, lacrimation, systolic blood pressure increase, respiratory irregularities and subjective feelings of narcotic withdrawal sickness (nausea, muscle aches, chills). A second group of 8 subjects showed, in addition to the above, evidence of conditioning of heart rate, respiratory rate, respiratory, rate and skin temperature decrease. These laboratory findings support the clinical reports of a conditioned withdrawal syndrome and suggest ways to improve treatment results by detecting and extinguishing or modifying conditioned responses.

Adult↗

PubMedDate not supplied

Expression of HOXD10 gene in normal endometrium and endometrial adenocarcinoma.

OBJECTIVE: Hox genes encode DNA transcription regulatory proteins that contain a conserved 61 amino acid protein called the homeodomain. Although best known for their role in cellular differentiation during embryonic development, aberrant expression of these genes has been associated with hematologic and solid neoplasms. The purpose of this study was to determine the relative expression of HOXD10 in human endometrial adenocarcinomas. METHODS: mRNA was isolated from 7 normal endometrial specimens and 28 endometrial adenocarcinoma specimens. cDNA was synthesized using random hexamer primers. The expression of HOXD10 relative to beta-tubulin (internal control) was assessed by densitometric comparison of co-amplified Phosphorus-32 (32P) labeled gene products separated by agarose gel electrophoresis. Direct sequencing of purified HOXD10 polymerase chain reaction product was also performed. RESULTS: The sequence of the purified HOXD10 product corresponds to the known DNA sequence reported in the National Institute of Health Gene Bank. mRNA expression of HOXD10 relative to beta-tubulin is significantly lower in endometrial carcinomas than in normal endometrium. Furthermore, the ratio of HOXD10 to beta-tubulin expression varies inversely with the histologic grade of the tumor (P = .0009). CONCLUSION: Cancer is a multistep process involving the aberrant expression of genes that regulate cell growth and differentiation. Human HOXD10 gene expression is altered in endometrial carcinoma and varies with the histologic grade of differentiation. This observation supports the theory that homeobox genes play a role in oncogenesis.

Adenocarcinoma↗

PubMedDate not supplied

Cyclin D1 overexpression and p53 mutation status in epithelial ovarian cancer.

OBJECTIVE: To examine the cyclin D1 mRNA expression level in ovarian tumor samples as compared with normal ovaries and to determine the relationship between cyclin D1 overexpression and p53 mutation status in ovarian tumors. METHODS: mRNA was isolated and cDNA was prepared from 27 epithelial ovarian tumors (3 tumors of low malignant potential (LMP) and 24 cancers) and 6 normal ovaries. The cyclin D1 sequences were amplified by using a thermal cycler in parallel with the beta-tubulin gene as an internal control. The cyclin D1 mRNA expression level relative to beta-tubulin was determined by 32P phosphoimager analysis. To confirm the overexpression of the cyclin D1 protein in ovarian tumor cells, immunostaining was performed. The p53 gene mutation status was examined by direct cDNA sequencing. RESULTS: mRNA levels of cyclin D1 were significantly higher in 21 (78%) of the 27 ovarian tumors than in normal ovaries. Cyclin D1 overexpression was detected in ovarian LMP tumors as well as in ovarian cancer cases. Positive immunostaining of cyclin D1 protein was observed in 10 of 18 (56%) ovarian tumors examined. p53 mutations were found in 11 (61%) of 18 ovarian tumors. Of 11 ovarian tumor cases with p53 mutations, 5 showed overexpression of cyclin D1. All 7 ovarian tumor cases without p53 mutations showed significant cyclin D1 mRNA overexpression. CONCLUSION: Cyclin D1 overexpression seems to be an early genetic event in ovarian tumor development. Although p53 may be one of the proteins whose function regulates the expression of G1 cyclins, ovarian tumors with no p53 mutation consistently showed cyclin D1 overexpression. Cyclin D1 overexpression may play an important role in the tumorigenesis of epithelial ovarian tumors.

Adenocarcinoma↗

PubMedDate not supplied

Expression of the protease inhibitor antileukoprotease and the serine protease stratum corneum chymotryptic enzyme (SCCE) is coordinated in ovarian tumors.

We have previously reported that the stratum corneum chymotryptic enzyme (SCCE) is overexpressed in ovarian cancers and that SCCE has potential as a useful marker and/or a therapeutic target for ovarian carcinoma. Antileukoprotease (ALP) has been shown to be a specific inhibitor of SCCE. The objective of this study was to investigate the potential cotranscription and overexpression of ALP in carcinoma of the ovary. The expression of ALP transcript was evaluated by Northern blot hybridization and by semiquantitative polymerase chain reaction (PCR) technique. The presence of the ALP protein in ovarian tumor cells was evaluated by immunohistochemistry. Northern blot hybridization showed that the ALP transcript was abundant in ovarian carcinomas but was not detected in the normal ovary. Semi-quantitative PCR examination revealed that the mRNA level of ALP was significantly elevated in low-malignant-potential tumors and in ovarian carcinomas compared with that in normal ovaries (P < 0.01). There was significant positive correlation between SCCE and ALP mRNA overexpression status in ovarian tumor cases (P < 0.01). Immunohistochemical expression of ALP protein was observed in ovarian tumor cells, whereas little or no staining was observed in normal ovarian surface epithelium. Like SCCE, ALP is highly overexpressed in ovarian tumor cells, which begs the question of whether it remains an effective inhibitor of SCCE or whether it is discordant in time or space and is ineffective as an inhibitor of the SCCE enzyme.

Adenocarcinoma, Clear Cell↗

PubMedDate not supplied

Metatarsal epiphyseal bracket: treatment by central physiolysis.

Longitudinal epiphyseal bracket (LEB) is a rare ossification anomaly in which an epiphysis brackets the diaphysis of a phalanx, metacarpal, or metatarsal. This abnormal epiphysis tethers longitudinal growth, resulting in a shortened and oval-shaped bone. Four patients with five LEBs were treated by central physiolysis and followed for a mean of 6 years. The patients had significant hallux varus deformity. Three patients had duplicated great toes, and two had tibia hemimelia significant enough to require epiphysiodesis as they neared adolescence. Resection of the LEB allowed the proximal and distal epiphysis to resume untethered growth. Silastic or methyl methacrylate was placed over the resected physis to prevent bony rebridging. The associated hallux varus deformity was corrected by capsulorrhaphy and K-wire fixation. In all patients, the metatarsal resumed longitudinal growth and correction of the hallux varus was maintained.

Child↗

PubMedDate not supplied

Mycoplasma pneumoniae infection associated with an acute brainstem syndrome.

A patient who developed an acute brainstem syndrome following Mycoplasma pneumoniae respiratory infection is reported. MRI showed changes consistent with brainstem demyelination. Clinical features and laboratory investigations support an immune mediated mechanism with no evidence of direction CNS invasion. On the basis of this case and a review of the literature, we postulate two mechanisms for the development of M. pneumoniae associated CNS disease: direct CNS invasion causing meningitis and an immune-mediated acute disseminated encephalomyelitis (ADEM). This has obvious therapeutic implications.

Adult↗

PubMedDate not supplied

The matrix metalloprotease pump-1 (MMP-7, Matrilysin): A candidate marker/target for ovarian cancer detection and treatment.

Matrix metalloproteases are known to play an important role in tumor invasion by mediating degradation of extracellular matrix. In this study, we have investigated the expression of the matrix metalloprotease pump-1 gene (also referred to as MMP-7, Matrilysin) in 44 ovarian tumors (12 low malignant potential tumors, 32 carcinomas) and 10 normal ovaries using quantitative PCR. The PCR product was labelled with 32P and a phosphoimager was used to determine the relative expression of pump-1 compared to an internal control beta-tubulin. mRNA expression levels of pump-1 were significantly elevated in 9 of 12 low malignant potential tumors and 26 of 32 carcinomas. Northern blot hybridization showed that the 1. 1-kb pump-1 transcript was abundant in carcinoma but seldom expressed in normal adult tissues including normal ovary. Immunohistochemical localization of the pump-1 protein confirms its expression by ovarian tumor cells. Our results suggest that pump-1 is frequently overexpressed in ovarian tumors and may contribute to its invasive nature or growth capacity, therefore pump-1 may serve as a useful marker for early detection of disease and/or a target for therapeutic intervention in downregulation of tumor progression.

Biomarkers, Tumor↗

PubMedDate not supplied

Increased expression of protease M in ovarian tumors.

Proteases are known to play important roles in tumor invasion and metastasis. Protease M, which was originally identified by Anisowicz and colleagues in 1996, is a new member of the serine protease family. We also identified the protease M transcript in a differential PCR screen of ovarian tumors and have investigated its expression in 44 ovarian tumors (12 low malignant potential tumors, 32 carcinomas) and 10 normal ovaries using quantitative PCR. The PCR product was labeled with (32)P and a phosphoimager was used to determine the relative expression of the protease M gene compared to internal control beta-tubulin. mRNA expression levels of protease M were significantly elevated in 9 of 12 low malignant potential tumors and 30 of 32 carcinomas. Northern blot hybridization showed that the 1.7-kb protease M transcript was abundant in carcinoma but not detected in normal ovary. Immunohistochemical staining of normal ovary and ovarian tumor tissue sections with antibodies generated to protease M derived peptides corroborated the semi-quantitative PCR and Northern analysis data. Our results suggest that protease M is frequently overexpressed in ovarian tumors and may therefore contribute to the invasive nature or growth capacity of ovarian carcinomas.

Adenocarcinoma, Clear Cell↗

PubMedDate not supplied

Ovarian tumor cells express a transmembrane serine protease: a potential candidate for early diagnosis and therapeutic intervention.

Proteases have been implicated in the extracellular modulation required for tumor growth and invasion. In an effort to categorize those proteases contributing to ovarian carcinoma progression, we have utilized redundant primers to conserved amino acid (AA) domains surrounding the catalytic triad of His, Asp and Ser to amplify serine proteases that are differentially expressed in carcinomas. Using this method, we have identified and cloned a serine protease named TADG-15 (tumor-associated differentially expressed gene 15) that is overexpressed in ovarian tumors. TADG-15 is a transmembrane multidomain serine protease which includes ligand binding domains and a serine protease in the extracellular space.

Amino Acid Sequence↗

PubMedDate not supplied

The CA 125 gene: an extracellular superstructure dominated by repeat sequences.

CA 125 has long presented problems to both clinicians and investigators because there was no definitive information on its structure and function. Here, we describe our work on cloning the CA 125 gene with the anticipation that such information will provide the basis for understanding its structure and its physiologic role in both normal and malignant tissues. The CA 125 protein core is composed of a short cytoplasmic tail, a transmembrane domain and an extraordinarily large glycosylated extracellular structure. This structure is dominated by a repeat domain composed of 156 amino acid repeat units which encompass the epitope binding sites. The molecule also includes an amino terminal domain of serine/threonine-rich sequences which would account for most of the O-glycosylation known to be present in CA 125. CA 125 is an unusually large transmembrane glycoprotein. Its release from the surface of the cell is most probably dependent on cytoplasmic phosphorylation followed by proteolytic cleavage. The extracellular domain is characterized by a large number of repeat units (probably 60+) which encompass an interactive disulfide bridged cysteine-loop and the site of OC125 and M11 binding. Sequencing the gene provides us with the ability to initiate the quest to understand the biological function of CA 125.

Amino Acid Sequence↗

PubMedDate not supplied

Epitopes on CA 125 from cervical mucus and ascites fluid and characterization of six new antibodies. Third report from the ISOBM TD-1 workshop.

CA 125 is found in body fluids in a variety of molecular weight forms. The largest species are found in normal abdominal fluid and cervical mucus. The present study therefore incorporated CA 125 derived from these sources as well as ascites fluid to investigate if the source of CA 125 influenced epitope characterization. Ascites-derived CA 125 varied in size from about 190 to about 2,700 kD. Cervical mucus-derived CA 125 treated with ultrasound changed its apparent size from more than 20,000 to 700 kD. Epitope mapping of antibodies was not grossly influenced by the size or source of CA 125 used as target. However, low-molecular-weight CA 125, i.e. ascites fractions CA 17/E, CA 17/F and CA 10/7, did show differences in certain assay combinations and cross-inhibition patterns which probably can be explained by steric effects due to the smaller size compared with the most abundant forms of CA 125 present in serum and other body fluids. The specificity of six new monoclonal antibodies to CA 125 was tested by cross-inhibition and immunometric assay combinations and compared to reference antibodies. One antibody, X306, belonged to the OC125-like antibodies. Four antibodies, X52, X75, X325 and VK8, were M11-like. The sixth antibody, 7C12, reacted with an epitope which was difficult to define. This antibody was inhibited by M11-like antibodies and OV197. However, used as an inhibitor, 7C12 inhibited only itself. We grouped it as an OV197-like antibody, but clearly different from OV197. The topography of epitopes was studied by analyzing all antibody pairs in immunoradiometric assays. These results confirmed the grouping of antibodies described above and are in accordance with previous findings that the highest signal is obtained using an OC125-like antibody or OV197 on the solid phase and an M11-like antibody as tracer. The composition of the sample in terms of high- and low-molecular-weight species of CA 125 was measured, with different responses depending on the antibody pair used. This might be one reason for discrepancies between assay results for CA 125 using different assays.

Antibodies, Monoclonal↗

PubMedDate not supplied

Arthroscopic anterior labral reconstruction using a transglenoid suture technique. Results in active-duty military patients.

We report the clinical outcome of arthroscopic labral reconstruction using a transglenoid suture technique in a young, active-duty military population. Forty-eight patients (49 shoulders) with varying degrees of glenohumeral instability underwent arthroscopic labral reconstruction using a transglenoid suture technique. All patients had traumatic injuries to their shoulders and all patients had magnetic resonance imaging scans demonstrating anterior labral tears. Postoperatively, the patients' shoulders were immobilized for up to 6 weeks. At a mean followup of 30 months (range, 12 to 49), 17 of the 41 patients (41%) with preoperative dislocation or subluxation had recurrent instability. Nine of these patients subsequently underwent open reconstruction procedures for recurrent instability. On the basis of the Rowe rating system, 53% had excellent or good results and 47% had fair or poor results. The overall perioperative complication rate was 14%. Suprascapular nerve palsy occurred in three cases (6%). Using the Fisher exact test, we determined that immobilization for 6 weeks postoperatively correlated with a lower recurrence rate in the patients with a history of glenohumeral dislocation (P = 0.007). The results of arthroscopic labral reconstruction using transglenoid sutures in the military patient are inferior to the reported 3% to 5% recurrence rate with open Bankart procedures, and the transglenoid pin technique jeopardizes the suprascapular nerve.

Adolescent↗

PubMedDate not supplied

Epidermal growth factor enhances secretion of the ovarian tumor-associated cancer antigen CA125 from the human amnion WISH cell line.

OBJECTIVE: We studied the relation between epidermal growth factor (EGF)/epidermal growth factor receptor (EGFR) and CA125 production in WISH cells. METHODS: We investigated quantitatively and immunohistochemically EGF-stimulated CA125 release from WISH cells and the effect of EGF on CA125 phosphorylation. RESULTS: Immunohistochemical staining demonstrated that CA125 and EGFR expression on the plasma membrane of the WISH cells was closely correlated with cell density. The WISH cell monolayers (day 4) stained for CA125 in both the cytoplasm and plasma membrane. By day 8, cells began to form clumps in the surrounding monolayer that were positive for membrane-associated CA125 and EGFR, while the monolayer was almost negative for both molecules. Four-day and 8-day cells exposed to EGF demonstrated a loss of both CA125 and EGFR staining. Epidermal growth factor increased the secreted CA125 levels by 50% in day-4 cells but had no effect on day-8 cells. CA125 from WISH cells was phosphorylated, and EGF further enhanced this phosphorylation.

Amnion↗

PubMedDate not supplied

More than 15 years of CA 125: what is known about the antigen, its structure and its function.

In 1997 CA 125 celebrated its 15th anniversary. Since the discovery of OC 125, an antibody that recognizes CA 125, by Bob Bast and his colleagues, considerable progress has been made toward the development of more sensitive and more precise assay systems. However, a great deal of mystery still remains about the CA 125 molecule and further enlightenment will probably not come until the gene for CA 125 is cloned and the complete open reading frame for the peptide core identified. In the meantime, we have learned some structural features of the CA 125 molecule as well as a little about its regulation and the requirements for its secretion or release from epithelial derived cells in cultures. The CA 125 molecule is almost certainly a glycoprotein with a predominance of O-linkages. It is heterogeneous with regard to both size and charge, most likely due to continuous deglycosylation of side chains during its life-span in bodily fluids. It exists as a very large complex (perhaps as much as 4 million daltons) under natural conditions. The core CA 125 subunit is in excess of 200,000 daltons and it retains the capacity to bind both OC 125 class antibodies and M 11 class antibodies. As a denatured purified subspecies the CA 125 molecule appears to autoproteolyse presumably due to an endogenous protease activity inherent to the molecule. Release or secretion of CA 125 appears directly linked to the epithelial growth factor receptor signal transduction pathway. Prior to its release from cultured cells, CA 125 is phosphorylated (at either/both serine and threonine) and dephosphorylated when released. To stimulate discussion on the regulation of CA 125 synthesis, its secretion and its structural configuration, we have presented a model of a theoretical CA 125 molecule. Perhaps it will provide a focus of attention until the CA 125 gene is cloned and the real molecule is described.

Antibodies↗

PubMedDate not supplied

Differential expression of matrix metalloprotease-7 in each component of uterine carcinosarcoma.

The aim of this study was to investigate the expression of matrix metalloprotease-7 (MMP-7) in each component of uterine carcinosarcoma. Surgical specimens of primary tumors of uterine carcinosarcomas were obtained from 13 patients. The carcinomatous component consisted of adenocarcinoma with or without squamous differentiation. The sarcomatous component consisted of spindle cell sarcoma, chondrosarcoma and rhabdomyosarcoma, either alone or in combination. The immunohistochemical expression of MMP-7 protein was examined using the avidin-biotin peroxidase complex technique employing the anti-MMP-7 monoclonal antibody. Expression of MMP-7 protein was detected in 9 (69.2%) of 13 adenocarcinoma components, while no staining was observed in any of the sarcomatous components examined. There was a statistically significant difference of the positive rate for MMP-7 between epithelial components and sarcomatous components of uterine carcinosarcoma (p<0.01). In some cases, MMP-7 was abundantly expressed at the invasive front of adenocarcinomas. It is concluded that MMP-7 protein is differentially expressed between the carcinomatous component and the sarcomatous component of uterine carcinosarcoma. Each component of carcinosarcoma may have its own potential for invasion and metastasis. MMP-7 may contribute to the invasive nature or growth capacity of the carcinomatous component of uterine carcinosarcoma, while it may not have a relation to that of the sarcomatous components.

Adenocarcinoma↗

PubMedDate not supplied

Overexpression of testisin, a serine protease expressed by testicular germ cells, in epithelial ovarian tumor cells.

OBJECTIVE: In a continued effort to identify and characterize secreted proteases that are overexpressed in ovarian carcinomas, we discovered the testisin protease as such a candidate. When this discovery was originally made, no data existed in the literature or in the GenBank database that identified such a gene. Our main objective was to determine whether this gene was overexpressed exclusively in ovarian tumor tissues compared with normal ovary and whether it was expressed in any other normal tissues. METHODS: mRNA was isolated and cDNA was prepared from 34 ovarian tumors (four adenomas, three low malignant potential tumors, and 27 carcinomas) and seven normal ovaries. The testisin mRNA expression level relative to internal control, beta-tubulin, was determined by Northern blot analysis and semiquantitative polymerase chain reaction (PCR). RESULTS: Northern blot hybridization showed that the testisin transcript was abundant in ovarian carcinoma but was not detected in normal ovary. On examination of Northern blots from normal fetal and adult tissues, only adult testis showed abundant transcripts of testisin. Semiquantitative PCR examination showed that the testisin mRNA levels in ovarian tumors of low malignant potential and in ovarian carcinomas were significantly higher than in normal ovaries (P <.01). Testisin mRNA level in ovarian carcinomas was also significantly higher than in ovarian adenomas (P <.05). Testisin overexpression rates in advanced stage (stage 2 or 3) diseases were significantly higher than that in early stage diseases (stage 1) in ovarian carcinoma samples (P <.05). CONCLUSIONS: The induction of the testisin transcript might contribute to the development, progression, and invasive or metastatic capacity of ovarian carcinomas.

Adenoma↗

PubMedDate not supplied

Cyclin E mRNA overexpression in epithelial ovarian cancers: inverse correlation with p53 protein accumulation.

OBJECTIVE: We investigated the relationship between cyclin E mRNA overexpression and p53 protein accumulation in epithelial ovarian cancers. METHODS: mRNA was isolated and cDNA was prepared from 36 epithelial ovarian tumors (three adenomas, three low malignant potential tumors, and 30 carcinomas), and six normal ovaries. The cyclin E mRNA expression levels relative to an internal control, beta-tubulin, were determined by semiquantitative polymerase chain reaction (PCR). Cyclin E and p53 protein expression in ovarian cancer tissues were examined by immunohistochemistry using the same series of samples. Fisher exact test of significance and an unpaired t test were used for statistical analysis. RESULTS: Considerable levels of cyclin E mRNA were detected in all normal ovaries and ovarian tumor samples examined by semiquantitative PCR amplification. mRNA levels of cyclin E were significantly higher in nine of 30 (30%) ovarian cancers compared with those in normal ovaries. The immunohistochemical expression of cyclin E protein was confirmed in the nuclei of tumor cells in 13 of 30 (43%) ovarian cancers. p53 protein accumulation was detected in 12 of 30 (40%) ovarian cancers examined. There was a significant inverse correlation between cyclin E mRNA overexpression and p53 protein accumulation (P <.01, Fisher exact test). CONCLUSIONS: Cyclin E mRNA overexpression frequently occurs in ovarian cancers without p53 protein accumulation. Cyclin E might have an important effect on the development of a limited number of ovarian cancers.

Adenoma↗