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Biomedical subjects

E Owens

Publications and source records attributed to E Owens.

At least 19 recordsLinked to original sources
PubMed2003

Clarifications on breakpoints in HSAX and BTAX by comparative mapping of F9, HPRT, and XIST in cattle.

The coagulation factor IX gene (F9), the hypoxanthine phosphoribosyl transferase 1 gene (HPRT1), and the X-inactive specific transcript gene (XIST) were physically assigned in cattle to analyze chromosomal breakpoints on BTAX recently identified by radiation hybrid (RH) mapping experiments. Whereas the FISH assignment of XIST indicates a similar location on the q-arm of the human and cattle X chromosomes, the locus of HPRT1 supported the assumption of a chromosome rearrangement between the distal half of the q-arm of HSAX and the p-arm of BTAX identified by RH mapping. F9 previously located on the q-arm of BTAX was assigned to the p-arm of BTAX using RH mapping and FISH. The suggested new position of F9 close to HPRT1 supports the homology between HSAXq and BTAXp. The F9 locus corresponds with the gene order found in the homologous human chromosome segment. XIST was assigned on BTAXq23, HPRT1 and F9 were mapped to BTAXp22, and the verification of the location of F9 in a 5000 rad cattle-hamster whole genome radiation hybrid panel linked the gene to markers URB10 and HPRT1.

Animals↗
PubMed2000

Effect of a la carte and snack bar foods at school on children's lunchtime intake of fruits and vegetables.

OBJECTIVES: To compare lunch fruit, juice, and vegetable (FJV) intake of fourth-grade students who receive only National School Lunch Program meals and fifth-grade students who also have access to a school snack bar and to compare FJV intake by meal source among fifth-grade students. DESIGN: Cross-sectional study: students completed FJV preference questionnaires and 5 days of lunch food records in classrooms. SUBJECTS/SETTING: 312 fourth- and 282 fifth-grade students in south Texas. MAIN OUTCOME MEASURES: Mean FJV consumption. STATISTICAL ANALYSES PERFORMED: Descriptive statistics, correlation analyses, analysis of variance, analysis of covariance. RESULTS: Fourth-grade students (n = 312) consumed significantly more fruits, juices, and vegetables (0.80 serving) than fifth-grade students (n = 282) (0.60 serving). Students whose parents reported a high school education or less consumed more regular and total vegetables than students whose parents reported some college or higher education. There were no interaction effects among gender, grade, ethnic, or family education groups. Fifth-grade students who ate only snack bar meals consumed significantly less total fruits, juices, and vegetables (0.40 serving) than fifth-grade students who ate school lunch meals (0.82 serving). Controlling for FJV preferences did not change the main effect for grade level in the FJV consumption models. APPLICATIONS/CONCLUSIONS: FJV consumption during school lunch is low. School foodservice staff should identify FJV items that middle school students prefer and increase availability of those items in middle school cafeterias and snack bars.

Beverages↗
PubMed2000

Socioenvironmental influences on children's fruit, juice and vegetable consumption as reported by parents: reliability and validity of measures.

OBJECTIVE: To pilot test theory-based questionnaires to measure socioenvironmental influences on children's fruit, juice and vegetable (FJV) consumption as reported by parents. DESIGN: Cross-sectional. SETTING: Parents of fourth to sixth grade students completed socioenvironmental questionnaires. The students completed food records (FRs) for 2 days in the classroom. SUBJECTS: Interviews were completed by 109 parents (17% African-American, 32% Hispanic-American and 51 Euro-American). RESULTS: Student mean daily FJV intake was 2.1 servings. Principal components analyses revealed subscales measuring positive and negative parenting practices; self-efficacy for modelling and planning/encouraging FJV consumption, and making FJV available; encouraging, consequences and discouraging food socialization practices; negative home, cost and canned/frozen food barriers; meal planning; child shopping; mother food preparation; and child lunch and dinner FJV preparation practices. Internal consistencies were adequate to high. Negative parent practices and negative home FJV barriers were significantly negatively correlated with child FJV consumption variables. Planning/encouraging self-efficacy was positively associated with fruit consumption, and child dinner FJV preparation was significantly negatively correlated with child juice consumption. CONCLUSIONS: These questionnaires may provide important insights about the relationship between parent-reported socioenvironmental influences and children's FJV consumption. Future work should test these questionnaires with larger groups of parents and youths, with more reliable estimates of usual FJV intake, e.g. 7-day food records, to obtain a detailed understanding of how parents influence what children eat. Tests of models of relationships among these variables are warranted, but should control for possible confounding variables, e.g. socioeconomic status, gender of the child, etc.

Adult↗
PubMed1999

The effect of patient position on intrarenal anatomy.

BACKGROUND AND OBJECTIVE: Although flexible ureteroscopes are designed with mechanisms for active and passive tip deflection, one of the major problems is the not infrequent inability to enter the lower pole calices. Accordingly, we measured the change in the lower pole infundibulopelvic (LIP) angle when the patient's position was varied (i.e., prone, supine, head down) during intravenous urography (IVU). PATIENTS AND METHODS: The LIP angle was measured in 20 right and 26 left adult kidneys during an IVU with the patient in six different positions: supine level, supine 20 degrees head down, supine 45 degrees head up, prone level, prone 20 degrees head down, and prone 45 degrees head up. None of the patients had a history of renal surgery. RESULTS: In all cases, the broadest angle of entry to the lower pole infundibulum was obtained with the patient in a prone position and 20 degrees head down. CONCLUSIONS: The LIP angle broadens when the patient lies in a prone 20 degrees head down position. This maneuver could improve the surgeon's ability to access the lower pole calices when performing flexible ureteronephroscopy.

Adult↗
PubMed1996

Prevention of skeletal muscle catabolism in sepsis does not impair visceral protein metabolism.

We investigated whether the preservation of gastrocnemius proteins by interleukin-1 receptor antagonist (IL-1ra) during sepsis altered protein metabolism in visceral tissues. Sepsis was induced by creation of an abdominal abscess followed by infusion of saline of IL-1ra. Five days later, the tissue protein content and rate of protein synthesis were measured. IL-1ra did not significantly alter hepatic protein metabolism in septic or control animals. In kidney, the protein content and rate of protein synthesis were both decreased by sepsis and significantly ameliorated by the infusion of IL-1ra. Sepsis decreased the rate of protein synthesis in the small intestine. IL-1ra increased intestinal protein synthesis in both control and septic animals; however, the effects were localized to the seromuscular layer. The preservation of muscle protein by IL-1ra in sepsis did not adversely affect protein synthesis in any of the visceral tissues examined. IL-1 appears to mediate the sepsis-induced changes in protein synthesis in kidney and small intestine but not in liver or spleen. Protein synthesis in each visceral organ responds differently to the septic insult and modulation of IL-1 bioactivity.

Abdomen↗
PubMed1994

Stallion karyotype variability and lack of association with abortion: a case report.

Karyotype analysis was done on a stallion that impregnated 23 mares during the 1991 breeding season, of which 14 aborted between 2 and 4 mo fo gestation. Lymphocytes examined contained a 64,XY complement of normal appearing sex chromosomes and autosomes, except for slight dimorphism of the centric heterochromatin of chromosome No. 1. A skin biopsy was procured form the stallion for karyotype analysis, and the stallion was bred to 11 mares. Three mares were detected pregnant 16, 35, 45 d after breeding. The fetuses were recovered transcervically using curved intestinal forceps 47 (n=2) and 49 (n=1) d after breeding. Fetal tissue was rinsed and packed in culture media, transported overnight in a chilled container, cultured by standard tissue culture techniques, and prepared for karyotype analysis. No abnormalities were found in standard karyotypes from those cultures. One fetal karyotype revealed slight dimorphism of the heterochromatin of chromosome No. 1. Chromosome spreads obtained from the stallion's skin biopsy revealed a normal karyotype with no difference in the amount of heterochromatin present in No. 1 chromosomes. During the 1992 breeding season, the stallion impregnated 23 of 25 mares bred. Only 1 mare aborted, at 8 mo of gestation. Apparently, the amount of heterochromatin of No. 1 horse chromosomes can vary, and caution should be used in diagnosing this as a cause of pregnancy failure.

Journal Article↗
PubMed1994

Interleukin-1 receptor antagonist prevents sepsis-induced inhibition of protein synthesis.

To understand the role of interleukin-1 (IL-1) as a mediator of the sepsis-induced skeletal muscle catabolism, we investigated the effects of a specific IL-1 receptor antagonist (IL-1ra) on skeletal muscle protein metabolism in a rodent model of chronic abdominal sepsis. A constant infusion of IL-1ra (2 mg.kg-1.h-1) or saline was begun immediately after the induction of sepsis and continued for 5 days. The effect of IL-1ra on protein metabolism was examined in individual muscles (gastrocnemius, soleus, heart) containing different fiber types. Infusion of IL-1ra in control animals did not alter protein metabolism in any of the muscles examined. Muscle weight, protein content, and the rate of protein synthesis in gastrocnemius were reduced by sepsis, whereas none of these parameters were affected in soleus or heart. Infusion of IL-1ra prevented the sepsis-induced loss of muscle protein and inhibition of protein synthesis in gastrocnemius but was without effect in soleus or heart. IL-1ra infusion restored translational efficiency in the gastrocnemius of septic rats and was without effect on the RNA content. These results provide evidence for a role of IL-1 as a mediator of the sepsis-induced abnormalities in skeletal muscle protein metabolism.

Abdomen↗
PubMed1991

Activity profiles of developmental toxicity: design considerations and pilot implementation.

The available literature was searched for quantitative test results from both in vitro and in vivo assays for developmental toxicity for five model compounds: cyclophosphamide, methotrexate, hydroxyurea, caffeine, and ethylenethiourea. These compounds were chosen on the basis of their extensive utilization in a variety of assay systems for developmental toxicity as evidenced by their representation in the ETIC database (each generally has 100-500 citations encompassing multiple test systems). Nine cellular-based assays, six assays using whole embryos in culture, as well as Segment II and abbreviated exposure tests for mammalian test species are included in the database. For each assay, the critical endpoints were identified, each of which was then provided a three-letter code, and the criteria for extraction of quantitative information were established. The extracted information was placed into a computerized reference file and subsequently plotted such that the qualitative (positive/negative) and quantitative (e.g., IC50, highest ineffective dose (HID), lowest effective dose (LED] results across all test systems could be displayed. The information contained in these profiles can be used to compare qualitative and quantitative results across multiple assay systems, to identify data gaps in the literature, to evaluate the concordance of the assays, to calculate relative potencies, and to examine structure-activity relationships.

Animals↗
PubMed1990

Preparation and biological evaluation of 18F-labeled benzamide analogs as potential dopamine D2 receptor ligands.

Three 18F-labeled benzamide derivatives were prepared and evaluated as potential ligands to study the dopamine D2 receptor phenomenon. The compounds are analogs of iodobenzamide, eticlopride and raclopride and are labeled with an N-2-[18F]fluoroethyl functionality on the pyrrolidine ring. The compounds were tested in vitro for binding affinity and found to exhibit somewhat lower affinity than the non-fluorinated analog. In vivo distribution studies revealed that all compounds were more highly bound to plasma proteins than was raclopride. In addition, compartmentation of radioactivity demonstrated nonspecific binding to be the predominate retention in the brain as reflected by the low caudate to cerebellum ratios for these compounds. These three 18F-labeled benzamide derivatives are inferior to raclopride and iodobenzamide for studies of the D2 receptor system using positron emission tomography.

Animals↗
PubMed1990

Kinetic analysis of 3-quinuclidinyl 4-[125I]iodobenzilate transport and specific binding to muscarinic acetylcholine receptor in rat brain in vivo: implications for human studies.

Radioiodinated R- and S-Quinuclidinyl derivatives of RS-benzilate (R- and S-125IQNB) have been synthesized for quantitative evaluation of muscarinic acetylcholine receptor binding in vivo. Two sets of experiments were performed in rats. The first involved determining the metabolite-corrected blood concentration and tissue distribution of tracer R-IQNB (active enantiomer) and S-IQNB (inactive enantiomer) in brain 1 min to 26 h after intravenous injection. The second involved the measurement of brain tissue washout over a 2-min period after loading the brain by an intracarotid artery injection of the ligands. Various pharmacokinetic models were tested, which included transport across the blood-brain barrier (BBB), nonspecific binding, low-affinity binding, and high-affinity binding. Our analysis demonstrated that the assumptions of rapid equilibrium across the BBB and rapid nonspecific binding are incorrect and result in erroneous estimates of the forward rate constant for binding at the high-affinity receptor sites (k3). The estimated values for influx across the BBB (K1), the steady-state accumulation rate in cerebrum (K), and the dissociation rate constant at the high-affinity site (k4) of R-IQNB were independent of the specific compartmental model used to analyze these data (K1 approximately 0.23 ml/min/g, K approximately 0.13 ml/min/g, and k4 approximately 0.0019 min-1 for caudate). In contrast, the estimated values of k3 and the efflux rate constant (k2) varied over a 10-fold range between different compartmental models (k3 approximately 2.3-22 min-1 and k2 approximately 1.6-16 min-1 in caudate), but their ratios were constant (k3/k2 approximately 1.4). Our analysis demonstrates that the estimates of k3 (and derived values such as the binding potential) are model dependent, that the rate of R-IQNB accumulation in cerebrum depends on transport across the BBB as well as the rate of binding, and that uptake in cerebrum is essentially irreversible during the first 360 min after intravenous administration. Graphical analysis was consistent with compartmental analysis of the data and indicated that steady-state uptake of R-IQNB in cerebrum is established within 1-5 min after intravenous injection. We propose a new approach to the analysis of R-IQNB time-activity data that yields reliable quantitative estimates of k3, k4, and the nonspecific binding equilibrium constant (Keq) by either compartmental or graphical analysis. The approach is based on determining the free unbound fraction of radiolabeled ligand in blood and an estimate of K1.(ABSTRACT TRUNCATED AT 400 WORDS)

Algorithms↗
PubMed1988

Performance inventory for profound and severe loss (PIPSL).

This study was undertaken to develop a quantifiable and reliable self-rating inventory specifically for persons with profound and severe hearing losses. Fifty such subjects with such losses who wore hearing aids rated themselves on a scale of 0-6 (never to always) on 125 items that sampled their performance in a variety of communicative situations. Items were assigned to tentative categories that were then refined so as to achieve high internal consistency, reflected by high alpha coefficients, with a minimal number of items. Six final categories, or scales, containing a total of 58 items, emerged with alpha coefficients .86 or higher. The scales were labeled Understanding Speech With Visual Cues, Intensity, Response to Auditory Failure, Environmental Sounds, Understanding Speech With No Visual Cues, and Personal. Another 16 items that failed to fit into any scale, and did not form a scale of their own, were also included in the final inventory because they related to individual rehabilitative concerns and activities in ways not represented among the items of the six scales.

Adult↗
PubMed1987

Local blood flow and vascular permeability of autonomic ganglion-transplants in the brain.

The purpose of this study was to determine whether the blood vessels of transplanted neural tissue retain their functional characteristics. Quantitative autoradiography was used to measure local blood flow (F) with iodoantipyrine and the blood-to-tissue transfer constant (K) with alpha-aminoisobutyric acid in superior cervical ganglion (SCG) allografted to the surface of ventricle IV and into the cerebellum of the same rat. The F of the intraparenchymal grafts was slightly lower than that of the intraventricular grafts; F decreased between 1 and 4 weeks in SCG grafts at both sites. The permeability-surface area (PS) product of the microvessels and extraction fraction of AIB were calculated from these results and indicated restricted transvascular passage of the amino acid in both the in situ and grafted SCG. Surface area (S) and average length (L) of the microvessels were determined morphometrically and their permeability (P) was calculated from these data. Although K and PS decreased in the grafts compared to in situ SCG, a comparable decrease in S indicated that P was similar for the microvessels of both in situ and 1-week-old SCG transplants: 3.5-4.3 x 10(-6) cm/s. Between 1 and 4 weeks after transplantation, the P of the microvessels decreased to approximately 1.6-2.3 x 10(-6) cm/s without any change in S. Thus, the blood vessels of SCG grafts within or upon the brain initially retain the functional attributes of in situ SCG microvessels, but the average permeability of the graft microvessels decreases to approximately one half of the initial value by 4 weeks after transplantation.

Alkaline Phosphatase↗
PubMed1987

The UCSF tracking procedure for evaluation and training of speech reception by hearing-impaired adults.

A tracking procedure that emphasizes practical coping strategies for hearing-impaired patients, along with practice in responding to other cues in the perception of connected speech, is described in detail in the course of its use with one subject. The subject's tracking scores before and after training illustrate the potential value of the procedure both as an evaluative measure and as a training tool. The organization of the materials and the design of the training protocol allow for a wide range of practice activities in tracking, including the use of nonverbatim as well as verbatim responses.

Aged↗
PubMed1986

Evaluation of lidocaine as an adjunct to fentanyl anesthesia for coronary artery bypass graft surgery.

A double-blind, randomized, prospective trial was conducted to evaluate intravenous lidocaine, 3 mg/kg, followed by an infusion of 0.05 mg X kg-1 X min-1, as an adjunct to fentanyl in 20 patients undergoing coronary artery bypass graft surgery. Lidocaine prevented hemodynamic abnormalities during tracheal intubation and after skin incision, but was ineffective in preventing hypertension following sternotomy. Intravenous lidocaine, 3 mg/kg, produced a decrease in mean arterial pressure after fentanyl, 30 micrograms/kg, that was unacceptable in some patients. Total fentanyl requirements for the duration of surgery were similar in the control group and in patients given lidocaine. We conclude that lidocaine, when administered as an adjunct to fentanyl in the dosage used in this study, can cause cardiovascular depression, and is of minimal benefit in preventing hemodynamic abnormalities after sternotomy during coronary artery bypass graft surgery.

Adjuvants, Anesthesia↗
PubMed1985

Visemes observed by hearing-impaired and normal-hearing adult viewers.

A series of VCV nonsense syllables formed with 23 consonants and the vowels /a/, /i/, /u/, and / / was presented on videotape without sound to 5 hearing-impaired adults and 5 adults with normal hearing. The two-fold purpose was (a) to determine whether the two groups would perform the same in their identification of visemes and (b) to observe whether the identification of visemes is influenced by vowel context. There were no differences between the two groups either with respect to the overall percentage of items correct or to the visemes identified. Noticeable differences occurred in viseme identification between the /u/ context and the other 3 vowel contexts; visemes with /a/ differed slightly from those with / / and /i/; and there were no differences in viseme identification for / / and /i/ contexts. Findings were in general agreement with other studies with respect to the visemes identified, provided it is acknowledged that changes can occur depending on variables such as talkers, stimuli, recording and viewing conditions, training procedures, and statistical criteria. A composite grouping consists of /p,b,m/; /f,v/; /theta sigma/; /w,r/; /tS,d3S,3/; and /t,d,s,k,n,g,l/.

Adult↗
PubMed1985

Regional measurements of [14C]misonidazole distribution and blood flow in subcutaneous RT-9 experimental tumors.

Regional [14C]misonidazole-derived radioactivity (MISO*) was measured by quantitative autoradiography in s.c. RT-9 experimental tumors 0.5, 2, and 4 h after an i.v. bolus (25 mg) and constant infusion (10 mg/h) in rats. Misonidazole (MISO) concentration in plasma, tumor, and other tissues was also measured by high-pressure liquid chromatography. The distribution of MISO* in the tumors always resulted in a characteristic pattern with high peripheral and low central values. The high-activity regions in the tumor rim achieved tissue: plasma MISO* activity ratios of 0.97 and 2.2 by 0.5 and 4 h, respectively; for central tumor regions, this ratio was 0.20 and 0.32 for the same periods, respectively. The limited distribution of MISO* to central tumor regions could be correlated to low values of blood flow (measured with [131I]iodoantipyrine) and to diffusion from peripheral tumor regions. Low blood flow in the central regions of these tumors will significantly limit the distribution of MISO and other drugs to viable-appearing cells in these areas and could account in part for the failures of chemotherapy in certain solid tumors. Pharmacokinetic modeling indicates that 1 to 9 h may be necessary for MISO concentrations in some tumor regions to reach 50% of that in plasma.

Animals↗