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Biomedical subjects

C Gillis

Publications and source records attributed to C Gillis.

30 records · Page 2Linked to original sources
PubMed1995

The epidemiology of non-seminomatous germ cell tumours in the west of Scotland 1975-89.

A total of 438 males resident in the six West of Scotland Health Board areas were notified to the cancer registry with a diagnosis of teratoma between 1 January 1975 and 31 December 1989. Non-registration was between 2% and 3.4%; a further 44 cases were ascertained through independent listings in the major tertiary referral centres. There were four (1%) duplicate registrations and 16 (4%) were incorrect on the basis of pathology (three) or residence (13). Of these, most (26) were registered with alternative diagnoses and eight were registered on the pre-1985 manual system. The positive correlation between socioeconomic status and incidence was confirmed by linking residential postcode at diagnosis to the Carstairs and Morris Deprivation Index. There was an increasing incidence, both overall and for men aged 15-44 years, with doubling times of 20 and 25 years respectively. The increase was confined to men resident in the more deprived postcode sectors; the incidence rate among men from the most affluent areas remained unchanged throughout the period of study.

Adolescent↗
PubMed1995

Effects of sera, basic fibroblast growth factor, heparin and cyclic AMP-stimulation on proliferation of human vascular endothelial cells.

The aim of this study was to find culture conditions that optimize the proliferation of human endothelial cells (ECs). The effects of different sera, growth factors and other additives on ECs derived from the adult human great saphenous or the umbilical vein were studied. Human serum (HS) at 10 and 40% was significantly more effective than fetal calf serum at 10 and 30%, respectively. The addition of basic fibroblast growth factor (bFGF) increased proliferation alone and in combination with heparin. Heparin alone increased EC growth only in medium containing 40% HS. The addition of cholera toxin (CT) and a phosphodiesterase inhibitor (IBMX) to raise cAMP-levels, stimulated proliferation of both cell types but was more pronounced on the ECs from the saphenous vein. The cAMP-levels were elevated equally in both cell types. However, db-cAMP stimulated proliferation only of the ECs from the saphenous vein. An additive stimulatory effect was observed when bFGF and CT/IBMX were combined. For saphenous vein ECs, a medium containing HS (40%), bFGF, heparin, CT and IBMX was found optimal for proliferation. We conclude that these compounds may be used to increase EC growth and that, even a limited number of donor ECs may be sufficient starting material for in vitro studies on the human endothelium.

1-Methyl-3-isobutylxanthine↗
PubMed1995

Ultrasonographic cross-sectional area and mean echogenicity of the superficial and deep digital flexor tendons in 50 trained thoroughbred racehorses.

Fifty Thoroughbred horses were examined. All horses had been in race training for a minimum of 4 months before examination and had worked at racing speed; 24 horses had raced. All horses were clinically sound at the time of examination. Ultrasonography was performed, using a 7.5-MHz transducer with built-in fluid offset. Videotaped images of the palmar soft tissue structures were obtained at 4, 8, 12, 16, 20 and 24 cm distal to the base of the accessory carpal bone (DACB). Images were digitized, and each image was calibrated. Values for cross-sectional area (CSA) and mean echogenicity (ME) were then determined from the cross-sectional images of the superficial digital flexor (SDF) and the deep digital flexor (DDF) tendons, using an image-analysis program. The SDF tendons were compared between right and left forelimbs at each level, and from proximal to distal on each limb, as were the DDF tendons. The relation between the SDF and DDF tendons for the same forelimb was determined at each level. There were no significant differences in CSA or ME at equivalent levels of the left and right SDF tendons. Mean (+/- SD) CSA was 1.01 +/- 0.12) cm2 at 4 cm DACB, 0.95 (+/- 0.14) cm2 at 12 cm DACB, and 1.12 (+/- 0.15) cm2 at 24 cm DACB. Adjusted ME was 2.34 (+/- 0.34) at 4 cm DACB, 2.03 (-/+- 0.38) at 12 cm DACB, and 2.04 (+/- 0.35) at 24 cm DACB. The left and right DDF tendons did not have significant differences in CSA or ME at any level. Cross-sectional area was 1.13 (+/- 0.18) cm2 at 4 cm DACB, 1.01 (+/- 0.12) cm2 at 12 cm DACB, and 1.75 (+/- 0.29) cm 2 at 24 cm DACB. Adjusted ME was 2.60 (+/-0.46) at 4 cm DACB, 2.49 (+/- 0.49) at 12 cm DACB, and 2.50 (+/- 0.44) at 24 cm DACB. At all levels, the left and right SDF tendons were smaller and less echoic than the DDF tendons of the same limb. The SDF and DDF tendons had an hour glass shape, with smallest CSA at 12 cm DACB. Mean echogenicity generally decreased for the SDF and DDF tendons from proximal to distal on the limb. These results indicate that for clinically normal trained Thoroughbred racehorses, there should be no significant difference in CSA or echogenicity between the left and right SDF tendons at equivalent distances DACB. There should be no significant differences in the left and right DDF tendons at equivalent levels DACB. The SDF tendon is usually smaller and less echoic than the corresponding DDF tendon at each level.

Animals↗
PubMed1995

Ultrasonography as a method to determine tendon cross-sectional area.

Ultrasonographic cross sectional area (CSA) measurements of equine superficial digital flexor (SDF) tendon were obtained to determine the feasibility of ultrasonography for CSA measurement of tendon in vivo and in vitro. Ultrasonographic measurements were compared with a more traditional CSA measurement method, ink-blot analysis. In addition, values for ultrasonographic SDF tendon mean echogenicity were obtained in vivo and in vitro. The left forelimb SDF tendons of 23 horses were evaluated ultrasonographically. Cross sectional images were acquired at 4-cm intervals distal to the base of the accessory carpal bone (DACB) to the level of the proximal sesamoid bones while horses were standing squarely. After euthanasia, the left forelimbs were mounted in a materials testing system (MTS) and loaded under tension to standing load. Ultrasonographic images were again acquired at the same locations. The ultrasonographic images were digitized, and values for ultrasonographic CSA and mean echogenicity were obtained for each level. immediately after mechanical testing, a 1-cm-thick transverse section of SDF tendon at 12 cm DACB was removed. Three ink blots were prepared from each end of the removed tendon section and digitized. The 6 CSA values were averaged to generate a value for morphologic CSA for each SDF tendon at 12 cm DACB. Standing ultrasonographic tendon CSA at 12 cm DACB was consistently smallest (mean +/- SD CSA 86 +/- 11 mm2), followed by MTS ultrasonographic CSA (mean, 95 +/- 12 mm), with ink-blot morphologic CSA being largest (mean, 99 +/- 15 mm2). Comparison of standing and MTS ultrasonographic CSA values at 12 cm DACB revealed a strong positive linear correlation between methods (R2 = 0.74, P = 0.001). Comparison of ink blot CSA at 12 cm DACB with standing and MTS ultrasonographic CSA revealed strong positive linear correlations (R2 = 0.64, P = 0.001 and R2 = 0.72, P = 0.001, respectively). For ultrasonographic mean echogenicity, standing values insignificantly exceeded MTS values at each level. The authors conclude that ultrasonography is a useful technique for the noninvasive assessment of SDF tendon CSA that can be applied in vivo and in vitro.

Analysis of Variance↗
PubMed1995

Effect of maturation and aging on material and ultrasonographic properties of equine superficial digital flexor tendon.

Results of studies in human beings and other species have indicated that aging significantly influences the strength, modulus of elasticity, and energy storage ability of tendon. We wanted to determine the effects of aging on the material and ultrasonographic properties of equine superficial digital flexor (SDF) tendon. Ultrasonographic measurements of left forelimb SDF tendon cross-sectional area and mean echogenicity were made in 23 standing horses ranging in age from 2 to 23 years. All horses had not been in work for a minimum of 6 months prior to the study. After euthanasia, left forelimb bone-muscle-tendon-bone specimens were mounted in a materials testing system. The SDF tendon was cyclically loaded sinusoidally 100 times at 0.5 Hz from 1.5 to 5.0% strain, then was submitted to 10-minute creep-and-stress relaxation tests. Modulus of elasticity, load at 3% strain, and creep-and-stress relaxation were determined for each specimen. A significant positive correlation was found between elastic modulus and age. Correlation was not found between age and SDF tendon cross-sectional area or mean echogenicity. When 2-year-old horses were compared with older horses, the latter had tendons with a significantly (P = 0.007) greater modulus of elasticity. The authors conclude that increasing age through maturity is associated with a corresponding increase in equine SDF tendon elastic modulus.

Aging↗
PubMed1994

Rapid visualization of viable and nonviable endothelium on cardiovascular prosthetic surfaces by means of fluorescent dyes.

Increasing interest in endothelialization of synthetic and tissue cardiovascular prostheses in vitro emphasizes the need for simple and rapid methods to evaluate presence of endothelium on surfaces. Scanning electron microscopy is a commonly used method for this purpose. In this study we investigated alternative and more rapid staining methods. Human saphenous vein endothelial cells in culture and on cardiovascular prosthetic materials (pyrolytic carbon, cusps of bioprosthetic heart valves, pig aorta, and expanded polytetrafluoroethylene) were labeled by exposing them to medium containing 5-chloromethylfluorescein diacetate or 1,1-dioctadecyl-3,3,3',3'-tetramethylindo carbocyanine perchlorate. For comparison, specimens were also fixed and processed for scanning electron microscopy. A bright fluorescence of endothelial cells labeled with 5-chlormethylfluorescein diacetate or 1,1-deoctadecyl-3,3,3',3'-tetramethylindo carbocyanine perchlorate wre clearly visualized in culture, on pyrolytic carbon, and on expanded polytetrafluoroethylene. Unfixed, prelabeled cells could be visualized immediately and unlabeled cells could be investigated for viability within 1 hour. Cells seeded on biologic tissue specimens could be visualized within 15 minutes with a modified hematoxylin-eosin staining. We suggest the use of these methods for rapid visualization of endothelium present on surfaces of cardiovascular prosthetic materials where they can partly replace the use of scanning electron microscopy.

Bioprosthesis↗
PubMed1993

Shifts in the Plutchik emotion profile indices following three weekly treatments with pulsed vs continuous cerebral magnetic fields.

Compared to baseline measures, the emotional profile indices of normal volunteers who received 3 weekly exposures to 20 min. of bilateral burst-firing magnetic fields along the temporal plane displayed increased aggression and decreased trust relative to those exposed to pulsed (1 sec. every 4 sec.) fields or to control conditions. The effect size was equivalent to an eta of 0.70. There were no shifts in Holtzman Inkblot Projection Scores. These results suggest that brief cerebral exposures to weak magnetic fields that simulate the burst-firing of amygdaloid cells may affect specific limbic emotions.

Adolescent↗
PubMed1993

Serum proteins provide a matrix for cultured endothelial cells on expanded polytetrafluoroethylene vascular grafts.

Endothelialization of prosthetic vascular grafts has been shown to increase patency. We studied the adhesion of cultured endothelial cells of adult human saphenous vein to serum protein coating on expanded polytetrafluoroethylene vascular grafts. The adhesion was compared with that on native or collagen type I-coated grafts. Scanning electron microscopy was used to analyze the precoating and the appearance of the added cultured cells. Presence of radioactively labeled saphenous vein endothelial cells was compared between precoated and uncoated grafts before and after exposure to pulsatile plasma flow. The adherence of saphenous vein endothelial cells was markedly increased on grafts coated with serum proteins or collagen. On both graft types the cells formed confluent areas, which were also present after the plasma flow. The technique was designed to promote endothelialization, using autologous serum as the main source for both growth stimulation during culture and adherence of endothelial cells to grafts. The method may be clinically useful for precoating and endothelialization of vascular grafts.

Blood Proteins↗
PubMed1992

Serial cultivation of adult human endothelium from the great saphenous vein.

The growth of endothelial cells from small segments of human great saphenous vein was investigated for possible functional studies of endothelial cell properties and endothelialization of cardiovascular prosthetic graft materials. Growth in medium containing fetal calf serum or human serum was compared, and the effects of adding compounds that increase intracellular cyclic adenosine monophosphate levels, that is, cholera toxin and isobutylmethylxanthine, were also examined. It was shown that human serum was more efficient in stimulating cell growth than fetal calf serum at all concentrations tested. It was also shown that the addition of cholera toxin and isobutylmethylxanthine significantly potentiated growth. Minimal Essential Medium with the addition of 40% human serum and cholera toxin (1 nmol/L) and isobutylmethylxanthine (33 mumol/L) was shown to be optimal. From a single segment (3 to 5 cm), 20 x 10(6) human saphenous vein endothelial cells corresponding to 2000 cm2 or more could be achieved after 3 to 4 weeks in culture. The human saphenous vein endothelial cell cultures retained their cobblestone appearance, expression of von Willebrand Factor (vWF)-antigen, and capacity for prostacyclin production after six passages. We suggest that this provides a practically useful method for studies of cultured endothelium and possibly for pre-endothelialization of cardiovascular prosthetic materials.

1-Methyl-3-isobutylxanthine↗
PubMed1991

Characterization, localization and actions of endothelins in umbilical vessels and placenta of man.

Endothelin-like immunoreactivity was observed in the endothelial lining of umbilical vein and artery as well as in the epithelium of the amniotic membrane. High levels of endothelin-like immunoreactivity (0.4-1.4 pmol g-1) were detected in human amniotic membrane, umbilical vessels and placenta. The concentration of endothelin-like immunoreactivity in the amniotic fluid was much higher (77 pmol l-1) than in umbilical cord plasma (10 pmol l-1). Characterization by reverse phase HPLC revealed that most of the endothelin-like immunoreactivity eluted in the position of synthetic endothelin-1 or oxidized endothelin-1. Specific, high affinity binding sites for endothelin-1 were present in placenta and umbilical artery. Endothelin binding sites were also found in cultured smooth muscle cells from the umbilical artery and vein. In the placenta, endothelin-1 and -3 were almost equipotent as competing ligands for endothelin-1 binding sites, whereas in the umbilical artery endothelin-3 was much less potent than endothelin-1. Scatchard analysis of the binding for placental membranes displayed a straight line (r = -0.994) indicating a single class of endothelin receptors with a Kd-value of 80 pmol l-1 and Bmax of 113 fmol mg-1. Endothelin-1 caused potent contractions of umbilical arteries and veins with threshold effects at 10 pmol l-1 while endothelin-3 had no contractile effect up to 10(-7) mol l-1. It is concluded that endothelin-1 predominates over other endothelins in umbilical vessels, amnion and placenta, and high levels of endothelin-1 was observed in foetal circulation and amniotic fluid. Endothelin-receptors seem to be of different types in placenta (ETB type) and umbilical vessels (ETA type).

Amniotic Fluid↗
PubMed1984

A poison education program for primary school.

A program with which to teach children in grades 1 and 2 to identify poisons and hazard symbols, to learn where poisons should be stored and to recognize a poisoning and contact a poison control center in the event of a poisoning was developed. Each objective was taught in one 30-minute lesson by the children's school teachers. Evaluation of the approximately 400 children who received the program by pre- and post-tests demonstrated that they learned to identify poisons, to recognize hazard symbols and the telephone number of the local poison control center. The children were also asked to identify their source of knowledge about poisons and cited parents, television and school as their most important sources.

Child↗