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Biomedical subjects

R Martin

Publications and source records attributed to R Martin.

At least 829 records · Page 46Linked to original sources
PubMedDate not supplied

Retroviral gene transfer into porcine keratinocytes following improved methods of cultivation.

We embarked on a program examining the application of cultured epithelial sheets to skin wounds in pigs using retroviral gene transfer as a means to follow the grafted cells. In the past similar studies have been hampered by an inability to grow porcine keratinocytes without seeding at an extremely high density. In this study we found that excellent results could be achieved with Opti-MEM-1 (Gibco BRL Life Technologies) containing 1 per cent foetal calf serum, 0.5 mM Ca2+ and no other growth factors or stimulants. Keratinocytes were plated on gamma-irradiated 3T3 feeders on surfaces which had previously been coated with rat tail collagen I. Keratinocyte cultures were established at a seeding density of 5 x 10(4) cm-2. The yield of cells from 1 cm2 of skin was sufficient to set up a 75 cm2 flask. Cultures reached 80-90 per cent confluence in 7-10 days, after which they were passaged 1:3 multiple times, taking 3-4 days to reach the same confluency. Allowing cultures to remain confluent for 1 week was sufficient to allow Dispase removal of an intact sheet. Using these techniques porcine keratinocytes were transduced at an average frequency of 25.3 per cent (+/- 14.0 SEM) with the retroviral vector MFG lacZ nls by growth on the gamma-irradiated retroviral producer line GP + envAm12.

Animals↗
PubMedDate not supplied

Primary lymphoma of the calcaneus with recurrence in the distal tibia: a case report.

Primary lymphoma of bone in general is a very rare condition which represents approximately 3% of all primary malignant bone tumors. Of these, less than 1% originate in the foot. The following case presentation demonstrates a patient who presented with primary lymphoma of the calcaneus, diagnosed by open bone biopsy and treated with radiation therapy. The patient remained disease free for almost 3 years, at which time recurrence to the contralateral distal tibia was diagnosed again through open biopsy.

Bone Neoplasms↗
PubMedDate not supplied

Intrathecal low-dose bupivacaine versus lidocaine for in vitro fertilization procedures.

BACKGROUND AND OBJECTIVES: Recent controversy with the use of intrathecal lidocaine has prompted the search for suitable ambulatory surgery alternatives. The purpose of our study was to evaluate the clinical utility of intrathecal low-dose bupivacaine for outpatient transvaginal oocyte retrieval. METHODS: Forty women enrolled and completed our prospective, randomized, double-blinded study of intrathecal hyperbaric bupivacaine 3.75 mg (0.5 mL of 0.75%) with fentanyl 25 microg versus hyperbaric lidocaine 30 mg (2.0 mL of 1.5%) with fentanyl 25 microg. Onset and level of sensory and motor block; time to ambulation, urination, and discharge; and intra- and postoperative complications (hypotension, pruritus, nausea, emesis, postdural puncture headache, post spinal pain syndrome [PSPS]) were recorded. Data were evaluated using analysis of variance, chi-squared, and Mann-Whitney U tests, with P <.05 considered significant. RESULTS: In demographically similar groups, no differences were noted in times to onset and recovery of sensory and motor function, or complications; however, times to voiding and discharge were significantly longer in the bupivacaine group. Four and 2 patients in the bupivacaine and lidocaine groups, respectively, required intravenous analgesic supplementation. One patient in the lidocaine group experienced PSPS. CONCLUSIONS: Although prolongation to voiding and discharge was observed, intrathecal hyperbaric bupivacaine 3.75 mg with fentanyl 25 microg is a viable anesthetic for oocyte retrieval.

Adjuvants, Anesthesia↗
PubMedDate not supplied

Lung mineral fibers of former miners and millers from Thetford-Mines and asbestos regions: a comparative study of fiber concentration and dimension.

Fiber dimension and concentration may vary substantially between two necropsy populations of former chrysotile miners and millers of Thetford-Mines and Asbestos regions. This possibility could explain, at least in part, the higher incidence of respiratory diseases among workers from Thetford-Mines than among workers from the Asbestos region. The authors used a transmission electron microscope, equipped with an x-ray energy-dispersive spectrometer, to analyze lung mineral fibers of 86 subjects from the two mining regions and to classify fiber sizes into three categories. The most consistent difference was the higher concentration of tremolite in lung tissues of workers from Thetford-Mines, compared with workers from the Asbestos region. Amosite and crocidolite were also detected in lung tissues of several workers from the Asbestos region. No consistent and biologically important difference was found for fiber dimension; therefore, fiber dimension does not seem to be a factor that accounts for the difference in incidence of respiratory diseases between the two groups. The greater incidence of respiratory diseases among workers of Thetford-Mines can be explained by the fact that they had greater exposure to fibers than did workers at the Asbestos region. Among the mineral fibers studied, retention of tremolite fibers was most apparent.

Aged↗
PubMedDate not supplied

Protective effects of ambroxol in hypothermic liver preservation: a transplant study.

The bronchosecretolytic agent ambroxol added to histidine-tryptophan-ketoglutarate (HTK) solution has recently been shown to protect cold stored rat hepatocytes. The aim of the present study was to confirm these observations in a rat liver transplantation model. Before orthotopic liver transplantation, donor livers from 30 syngeneic Wistar rats were assigned to three groups (n = 10): (A) in situ flush (ISF) and 1/2-h cold storage (CS) with HTK solution, (B) ISF and 3-h CS with HTK, and (C) ISF and 3-h CS with HTK + 10(-3) mol/L ambroxol. The efficacy of the drug was evaluated by postoperative survival (> 14 days) and liver enzyme release (ALT), bile flow, histomorphological injury, and malondialdehyde (MDA) level in the grafts 15 min after reperfusion. After 1/2-h CS with HTK solution (A), 90% of the transplanted rats survived. In comparison with donor conditions, bile flow in the reperfused grafts decreased to 87 +/- 5.3%, whereas postoperative ALT levels slightly increased. After 3-h HTK preservation (B), the survival rate decreased to 60%, while ALT values markedly increased and bile flow after reperfusion declined to 82 +/- 6.6%. Ambroxol added to HTK solution (C) enhanced bile flow to 106 +/- 3.4%(p < .05), and reduced ALT and MDA levels and histomorphological injury of the transplanted livers, so that its beneficial effect in organ preservation has been confirmed in the transplant model. However, survival rate was not improved by the agent, probably because of the low cold ischemia tolerance of the Wistar rat livers used.

Alanine Transaminase↗
PubMedDate not supplied

A radiographic model for simulating rheumatoid erosions.

Lesions were mechanically created in bone specimens to find a radiographic model for skeletal disease. Drilling, sawing, and filing of the bones did not satisfactorily simulate skeletal pathology. Chipping of the juxta-articular cortex resulted in cortical defects that closely resemble rheumatoid erosions. The radiographs of 25 patients with rheumatoid arthritis were reviewed using optical magnification to determine the size and distribution of actual rheumatoid erosions. Using the pattern of erosions in the patient population, lesions can be distributed in varying sizes to produce a radiographic model for rheumatoid erosions. This model can be used for observer performance studies and to evaluate imaging technology.

Adolescent↗
PubMedDate not supplied

Adolescent pregnancy, tattooing, and risk taking.

PURPOSE: To determine pregnant adolescents' interest in tattooing and identify additional risk-taking behaviors practiced by tattooed pregnant adolescents. DESIGN: A descriptive study with a convenience sample of 41 pregnant adolescents was conducted. The majority of participants were 16 to 17 years of age, 7 to 9 months gestation, single, in the 10th to 11th grades, and primarily White. A subgroup of five participants were tattooed. Participants completed the 71-item Armstrong Tattoo (AT) questionnaire. Descriptive statistics were used to describe the sample and evaluate responses. RESULTS: The majority of adolescents expressed interest in becoming tattooed; 48% expressed fear (disease, pain) as a deterrent to becoming tattooed. All tattooed participants had received tattoos prior to pregnancy. Decisions to become tattooed were made rapidly at 14 to 16 years of age, and all tattooed participants were impregnated by tattooed males. Most tattooed participants perceived themselves as risk takers, and all denied additional health problems (infection, blood-borne disease) related to the tattooing process. CLINICAL IMPLICATIONS: Proactive, preventive health education regarding maternal/fetal risks related to amateur and professional tattooing during pregnancy is needed. Pregnant adolescents aged 14 to 16 years who are dating a tattooed male may be at greater risk for impulsively deciding to become tattooed.

Adolescent↗
PubMedDate not supplied

Comparison of Thayer-Martin, Transgrow, and Gonozyme for detection of Neisseria gonorrhoeae in a low-risk population.

The Gonozyme test (Abbott Laboratories, North Chicago, IL) an enzyme-linked immunosorbent assay procedure, on-site Thayer-Martin cultures, and Transgrow cultures were compared for sensitivity and specificity in detecting gonorrhea. For these comparisons triplicate genital swab specimens were obtained from women for the diagnosis of infection with Neisseria gonorrhoeae. Both the Transgrow and the Gonozyme specimens were mailed to a public health laboratory. The population under study was considered to be low-risk. When sensitivity and specificity were calculated on the basis of results of Thayer-Martin cultures, Transgrow had a sensitivity of 57% and a specificity of 100%. Gonozyme had a sensitivity of 80% and a specificity of 99%. In a low-risk population, the predictive value of a positive Transgrow culture was 100%, whereas the predictive value of a positive Gonozyme test was 57%. The predictive value of a negative Transgrow result was 99.7%, and that of a negative Gonozyme test was 99.8%. It is concluded that the use of the Gonozyme procedure for screening of low-risk populations needs further evaluation.

Bacteriological Techniques↗
PubMedDate not supplied

Can prosody aid the automatic classification of dialog acts in conversational speech?

Identifying whether an utterance is a statement, question, greeting, and so forth is integral to effective automatic understanding of natural dialog. Little is known, however, about how such dialog acts (DAs) can be automatically classified in truly natural conversation. This study asks whether current approaches, which use mainly word information, could be improved by adding prosodic information. The study is based on more than 1000 conversations from the Switchboard corpus. DAs were hand-annotated, and prosodic features (duration, pause, F0, energy, and speaking rate) were automatically extracted for each DA. In training, decision trees based on these features were inferred; trees were then applied to unseen test data to evaluate performance. Performance was evaluated for prosody models alone, and after combining the prosody models with word information--either from true words or from the output of an automatic speech recognizer. For an overall classification task, as well as three subtasks, prosody made significant contributions to classification. Feature-specific analyses further revealed that although canonical features (such as F0 for questions) were important, less obvious features could compensate if canonical features were removed. Finally, in each task, integrating the prosodic model with a DA-specific statistical language model improved performance over that of the language model alone, especially for the case of recognized words. Results suggest that DAs are redundantly marked in natural conversation, and that a variety of automatically extractable prosodic features could aid dialog processing in speech applications.

Decision Trees↗
PubMedDate not supplied

Hyperalimentation during pregnancy: a case report.

Severe, prolonged hyperemesis gravidarum was managed with total parenteral nutrition throughout three trimesters. Reversal of maternal weight loss and adequate fetal growth were achieved. A viable, large for gestational age infant was delivered prematurely at 34 wk. Serum values for selected nutrients, taken at delivery from maternal and cord blood, suggest that present estimates of parenteral nutritional needs for vitamins and minerals during pregnancy are probably low. An important corollary to maternal weight gain and caloric intake is to provide adequate nutrition as early as possible for optimal fetal weight gain.

Adult↗
PubMedDate not supplied

[A controlled study of irrational interpretations of intrusive thoughts in obsessive-compulsive disorder].

UNLABELLED: Recent research suggested that the irrational interpretations of intrusive thoughts might be cognitive structures underlying obsessive compulsive disorder (OCD). We present a study on intrusive thoughts and their interpretations in 36 patients suffering from OCD (DSM IV criteria), compared with 36 sex and age matched non clinical subjects, with the Intrusive Thoughts and their Interpretations Questionnaire-revised version (ITIQ-r). This questionnaire measures intrusive thoughts intensity and three types of interpretation: responsibility, guilt and inferiority. The measures of OCD, of depression, of social phobia and of anxiety have been used. RESULT: OCD patients reported more frequent intrusive thoughts and higher irrational interpretations than controls. The higher the intrusive thoughts, the higher the irrational interpretations. The multiple regression showed that both intrusive thoughts and irrational interpretations were respectively predicted by obsessional compulsive pathology (the Obsessive Thoughts Checklist or the Y-BOCS). The Y-BOCS was the only predictor for inferiority interpretation, but there was no significant predictor for responsibility or for guilt interpretations. Responsibility correlated only with aggressive intrusive thoughts. Guilt was related to intrusions about fear of loss. Inferiority was highly correlated with intrusive thoughts about perfectionism and sexuality.

Adolescent↗
PubMedDate not supplied

Interleukin-2 and blood brain barrier in cats: pharmacokinetics and tolerance following intrathecal and intravenous administration.

Single bolus doses of glycosylated human interleukin-2 (n IL-2) in the range of 2.8 x 10(3) to 2.0 x 10(6) IU/kg were administered to anesthesized cats via the cephalic vein (n = 10) or using suboccipital puncture (n = 8). CSF (cerebrospinal fluid) and blood samples were collected by repeated puncture. The n IL-2 concentration in four cats was determined on the basis of its biologic activity using 3H-thymidine incorporation into human ConA-blasts and by radioimmunoassay. In additional experiments radioactivity was determined in cerebrospinal fluid and serum after intravenous and intrathecal (i.th.) application of 5.8 x 10(3) - 3.2 x 10(3) IU/kg of 14C-acetyl-n IL-2 in regular time intervals. CSF and serum concentration time-profiles show a biexponential decline in the plasma elimination phase with half-lives of 4 min (alpha-phase) and 90 min (beta-phase) after intravenous and 20-120 min (alpha-phase) and 2-16 hours (beta-phase) after intrathecal application. There is a trend towards longer terminal elimination half-lives with increasing doses. Interleukin-2 is able to penetrate the blood brain barrier from the circulation into the cerebrospinal fluid and vice versa. Due to a slow rate of penetration and rapid elimination from blood only traces of n IL-2 (2-8 IU/ml) are detected in CSF after i.v. injection of 2 x 10(6) IU/kg, whereas concentrations between 400 and 1600 IU/ml are maintained in CSF for several hours following i.th. administration of 2-10 x 10(5) IU/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

[Age-dependent changes in glucocorticoid receptors in rat liver following functional loading in in-vivo and in-vitro systems].

In aging the transformation, nuclei binding, and recycling of glucocorticoid receptor complexes (GRC) seem to be retarded or disturbed, as shown in the rat liver after stress and in an in vitro-system. Reasons of the retarded in vitro-transformation and DNA-binding could be changed properties of the receptor protein or of cytosolic modulators, in which the tested heat-stable factor f is not responsible for the aging changes. The observed aging differences, when studying the nuclei binding after Ca2+ addition, result in the question, to what extent phosphorylation/dephosphorylation processes play a role in transformation and nuclei binding of GRC.

Aging↗