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Biomedical subjects

C Martin

Publications and source records attributed to C Martin.

At least 1,333 records · Page 74Linked to original sources
PubMedDate not supplied

Early shunting of 9 microns and 15 microns tracer microspheres from the acutely ischemic canine myocardium.

Recent reports have shown considerably differing results for myocardial shunting of 9 microns and 15 microns tracer microspheres (TMs) under various conditions. This could restrict the use of TMs for myocardial, especially collateral blood flow measurements. To determine the importance of coronary collateral blood flow and its early changes during the first 30 minutes after acute coronary artery occlusion (i.e. the 1st arrhythmic phase), we studied the shunting of 9 microns and 15 microns TMs from the ischemic myocardium during acute LAD ligation. In anesthetized dogs these TMs and subsequently Ringer solution were infused into the occluded coronary artery just distal to the ligation with constant low perfusion pressure. TM shunting (%S) into the lungs was then determined (%S = total lung radioactivity . 100/radioactivity infused). During a single LAD occlusion lasting 35 minutes (series I, n = 10) 9 microns TMs were infused immediately and 30 minutes after ligation, 15 microns TMs being infused after 15-20 minutes. In series II (n = 6) 9 microns TMs were infused immediately during the 1st, short (5 minutes) LAD occlusion. Following 90 minutes of reperfusion a 2nd LAD ligation (35 minutes) was performed with 9 microns TMs being infused immediately and 30 minutes after occlusion. During the first 30 minutes of acute coronary artery occlusion, TM shunting from the ischemic myocardium is negligible for 15 microns TMs (%S less than 0.5%; n = 5), whereas the mean 9 microns TM shunt of the early applied TM (i.e. A1, series I; n = 9; B2, series II; n = 6) amounts to a maximum of 1.21 +/- 0.2% (X +/- SEM). After 30 minutes of occlusion the mean 9 microns TM shunt amounts only to 0.71 +/- 0.15% (i.e. C1, series I; n = 4; C2, series II; n = 4). - In a coronary artery occlusion repeated once, 9 microns TM shunting, while increasing slightly due to the 90 minutes of reperfusion, still amounts to only 1.73 +/- 0.41% (n = 6). In three experiments 9 microns TMs were infused into the unoccluded, normally perfused LCX coronary artery during LAD occlusion. The mean LCX shunt value of 4% after a mean time of 25 minutes following TM infusion is in very good agreement with the 9 microns TM shunt values in the literature. These results clearly demonstrate that the TM technique with 9 microns microspheres is suitable for measuring changes in coronary collateral blood flow at least for a short time period after acute coronary artery occlusion.

Acute Disease↗
PubMedDate not supplied

Preparation and dissolution rate of gliquidone-PVP K30 solid dispersions.

Solid dispersions of gliquidone in PVP K30 were prepared by the solvent method. These dispersions were characterized using X-ray diffraction. In comparison with the drug alone, the physical mixtures and even more the solid dispersions showed an increase in the dissolution rate. Moreover these solid dispersions were stable during storage.

Drug Stability↗
PubMedDate not supplied

Parameters of emotional processing in neuropsychiatric disorders: conceptual issues and a battery of tests.

Components of emotional processing were examined in psychiatric and neurological populations: communication channel (face/voice), processing mode (expression/perception), and emotional valence (positive/negative). These were assessed with an experimental affect battery which was administered to schizophrenic, unipolar depressive, right-brain-damaged, Parkinson's disease, and normal control right-handed adults. For expression, subjects were taped while producing facial and vocal emotional expressions. Judges rated the expressions for accuracy and intensity. For perception, subjects were asked to identify and discriminate facial and vocal emotions. Using correlational techniques, relationships between facial and vocal channels and between expressive and perceptual modes were explored. The test battery has good psychometric properties and discriminates among diagnostic groups.

Adult↗
PubMedDate not supplied

Dose-dependent suppression of the high alcohol intake of chronically intoxicated rats by Ca-acetyl homotaurinate.

The effect of taurine derivative, Ca-acetyl homotaurinate, on voluntary alcohol intake was investigated in ethanol-dependent and naive rats. A high 24 hr oral intake of a 10% ethyl alcohol solution (9-10 g/kg) was exhibited by rats following 15 days of intragastric infusions of ethanol (7-8 g/kg/day). In four groups, rats were IG injected by short pulses of isotonic saline or a daily dose of 200, 300 and 450 mg/kg respectively, distributed over six daily infusions during alternating 8 hr presentations of ethanol solution and water. Compared to their respective basal intakes during the first two days of injection, the rats demonstrated a dose-dependent 50 to 70% reduction in alcohol consumption with drug treatment. This suppression effect was specific to the ethanol solution and persisted during 4 days of post-treatment observation. In ethanol-naive rats similarly tested and drinking half the amount of alcohol drunk by their ethanol-dependent counterparts, only the highest dose of drug (450 mg/kg) significantly suppressed their alcohol intake. It is suggested that Ca-acetyl homotaurinate interacts with CNS mechanisms involved in the ethanol tolerance-dependence state, underlying an enhanced reinforcing property of ethanol oral intake. Opioid receptors could be the targets in this action.

Acamprosate↗
PubMedDate not supplied

Ribotyping of Streptococcus agalactiae strains isolated from vaginas of asymptomatic women.

One hundred and eleven strains of Streptococcus agalactiae isolated from vaginas of asymptomatic women were characterized by determination of restriction length polymorphism profiles of rDNA regions (rDNA RFLP patterns) and serotyping. Thirty-five different PstI rDNA RFLP patterns were identified. Half of the strains fell into only seven of these 35 groups. No correlation between serotypes and rDNA RFLP patterns was found. These results indicate that (i) the genetic diversity of the S. agalactiae species is relatively limited and (ii) determination of rDNA RFLP patterns can be used as a typing system only in conjunction with serotyping.

Bacterial Typing Techniques↗
PubMedDate not supplied

Effect of platelet-derived growth factor on tibial osteotomies in rabbits.

The effect of exogenous platelet-derived growth factor (PDGF) BB on bone healing was tested in a pilot study using a unilateral tibial osteotomy in rabbits. Each osteotomy was injected with collagen or collagen containing 80 micrograms of PDGF. At 28 days, both tibiae from each rabbit were harvested and subjected to three-point bending to failure. The effect upon bone healing was tested by comparing the healing rates of PDGF-treated and -nontreated osteotomies with their respective normal contralateral bones. Three animals died before 28 days. The remaining 6 experimental and 5 control animals were available for assessment. Radiographically, at 2 weeks and 4 weeks, there was a clear increase in callus density and volume around the PDGF-treated osteotomies compared with the control rabbits' osteotomies. Osteotomies treated with PDGF were not statistically different in strength from their nonoperated contralateral bones. In the control group, however, the osteotomies were statistically weaker than their nonoperated (contralateral) bones. Microscopically, it was generally observed that PDGF-treated tibiae displayed a more florid and advanced state of osteogenic differentiation, both endosteally and periosteally, than the control osteotomies. Radiographic, mechanical, and histopathological data suggest that exogenous PDGF has a stimulatory effect on fracture healing.

Animals↗
PubMedDate not supplied

An adduct of cis-diamminedichloroplatinum(II) and poly(ethylene glycol)poly(L-lysine)-succinate: synthesis and cytotoxic properties.

A noncovalent adduct of the antineoplastic drug cis-diamminedichloroplatinum (cDDP) and a biocompatible graft copolymer of poly(L-lysine) and methylpoly(ethylene glycol) succinate is described. Upon incubation of cDDP with [O-methylpoly(ethylene glycol)-O'-succinyl]-N- epsilon-poly(L-lysine)n-N-epsilon-succinate, n = 250-270, highly soluble, long circulating adducts were formed which contained 4.3% of platinum by weight. Approximately 60% of the polymer-associated drug was released during dialysis against saline or serum albumin containing saline, with a half-time of release of 63 h. The adducts showed a pronounced antineoplastic effect in BT-20 human adenocarcinoma cell cultures. In cell proliferation assays, the concentration of half-inhibition of [3H]thymidine uptake was 0.9 +/- 0.2 microM for the drug-copolymer adduct compared to 0.3 +/- 0.1 microM for free cDDP. The adduct showed a long blood half-life (ca. 14 h in rats) and accumulated in experimental mammary adenocarcinomas at 2.5-3.5% injected dose per gram of tissue. A control adduct of cDDP with the backbone portion of the copolymer, poly(L-lysine)-N-epsilon-succinate, had a short half-life in the bloodstream (ca. 30 min) and low accumulation (0.5% injected dose per gram) in tumor. A dual therapeutical effect of methylpoly(ethylene glycol)succinylpoly(L-lysine)-succinate as a carrier of cDDP is suggested: (1) as a carrier for systemic release of the active drug from the macromolecule while it circulates in the bloodstream and (2) as a carrier for on-site delivery which results from the release of the drug in the tumor as a consequence of accumulation of the copolymer in the tumor.

Adenocarcinoma↗
PubMedDate not supplied

Cervical implant from villoglandular endometrial adenocarcinoma masquerading as cervical villoglandular adenocarcinoma.

This is an unusual presentation of a rare subtype of endometrial adenocarcinoma (villoglandular papillary carcinoma, VGPC) in a 71-year-old woman, which was initially diagnosed on cervical biopsy as being primary cervical VGPC. Loop excision failed to show any evidence of residual disease. Subsequent hysterectomy revealed a localized villoglandular carcinoma involving the uterine fundus and invading the inner one-third of the myometrium, the background endometrium was atrophic. The remaining cervix contained a focus of papillary forming endometrial type adenocarcinoma involving the surface epithelium and the superficial subepithelial glands. In conclusion, VGPC of cervix occurs mainly in young women and can be treated conservatively, pathologists should be cautious in making such a diagnosis in a postmenopausal woman before ruling out a primary endometrial origin.

Adenocarcinoma, Papillary↗
PubMedDate not supplied

Antibody elution from red blood cells by chloroform and trichloroethylene.

Antibody elution by chloroform and trichloroethylene was compared with the Rubin ether method modified by Hughes-Jones for IgG antibodies and the Landsteiner and Miller heat method for IgM antibodies. After washing the cells, the chloroform and trichloroethylene method was done at 37 degrees C for 10 minutes. With this technique the eluate remained on the upper layer above the red blood cell stroma layer, while with Rubin's method the eluate remained below the cell stroma. The reported technique was as effective as the Landsteiner and Miller heat method for IgM antibodies, and a double volume of eluate was obtained.

Blood Group Antigens↗
PubMedDate not supplied

Cereal supplementation modified the fibrolytic activity but not the structure of the cellulolytic bacterial community associated with rumen solid digesta.

4 ruminally cannulated cows were fed a forage diet (93% hay + 7% straw) and a mixed diet (33 % hay + 7% straw + 40% barley) in a 2 x 2 crossover experimental design. In sacco degradation of forage, fibrolytic activities (polysaccharidases and glycosidases) of the solid-associated bacteria (SAB), and distribution of the 3 main cellulolytic bacterial species (Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens) were determined for both diets. Barley supplementation decreased the hay degradation rate and mainly the polysaccharidase activities of the SAB (30% on average). The sum of rRNA of the 3 cellulolytic bacterial species represented on average 17% of the total bacterial signal and R. albus was the dominant cellulolytic bacterial species of the 3 studied. Barley supplementation did not modify the proportion of the 3 cellulolytic bacteria attached to plant particles. The negative effect of barley on the ruminal hay degradation rate is due to a decrease in fibrolytic activity of the SAB, and not to a modification of the balance of the three cellulolytic bacterial species examined.

Animal Feed↗
PubMedDate not supplied

Development and validation of a novel technique for murine first-pass radionuclide angiography with a fast multiwire camera and tantalum 178.

BACKGROUND: The use of genetically altered mice as a model system to study cardiovascular disease has created a need for accurate and quantitative assessment of murine ventricular function. To address this very challenging problem, we have developed a technique of murine first-pass radionuclide angiography using pinhole imaging and the short-lived isotope tantalum 178 (Ta-178) with a high-speed multiwire proportional camera (MPC). METHODS AND RESULTS. An MPC was fitted with a pinhole lens of 2-mm-diameter aperture positioned 15 cm from the camera face. The short-lived isotope Ta-178 (half-life 9.3 minutes) was generated from the tungsten 178 (W-178) (half-life 21.7 days)/Ta-178 generator and concentrated on site to an injection volume of 15 to 20 microL. Mice were imaged in the supine position with the chest wall 3 mm from the camera pinhole aperture, and images were acquired at 160 frames per second after a rapid bolus injection of Ta-178. In the absence of a true gold standard, the technology was validated with measurements in control mice and mice with surgically ligated left anterior descending arteries (LADs). In addition, the effects of pharmacologic intervention with verapamil and with dobutamine were observed. Finally, peak aortic velocity measurements obtained with this technology were compared with those obtained with echocardiographic Doppler ultrasonography, the only available quantitative comparator. There was a significant decrease in the mean left ventricular ejection fraction (LVEF) between normal mice (62% +/- 4.6% [mean +/- SEM], n = 12) and mice with experimentally induced myocardial infarction produced by surgical LAD ligation (22% +/- 2.0%, n = 41; P <.01). The LVEF decreased from 51% +/- 5.8% to 37% +/- 3.5% in a group of normal mice receiving verapamil (P <.05, n = 8) and increased from 34% +/- 2.2% to 43% +/- 2.3% in a group of LAD-ligated mice receiving dobutamine (P <.01, n = 48). Peak camera sensitivity during first pass was 25,000 cps/mCi injected. Intraobserver and interobserver variability of LVEF was studied, yielding r = 0.9639 and 0.9529 and SE of the estimate 2.6% and 3.1%, respectively. Reproducibility in serial studies was excellent (r = 0.92, SE of the estimate 5.18). CONCLUSIONS: This study demonstrates the development and use of a promising new method that uses the short-lived radioisotope Ta-178 and MPC for noninvasive quantification of murine ventricular function, that produces accurate and highly reproducible results, and that can be applied in multiple serial studies.

Animals↗
PubMedDate not supplied

Use of a long-acting somatostatin analogue (SMS 201-995) in controlling a significant ileal output in a 5-year-old child.

We report the efficacy of a long-acting somatostatin analogue, associated with conventional therapy, in controlling profuse ileostomy losses in a child with short bowel syndrome following a volvulus. The first therapeutic effects of the treatment [50 to 100 micrograms/day of SMS 201-995 (Sandoz Ltd.) subcutaneously] appeared 48 h after institution. Ileal output was reduced on an average from 1,800 to 600 ml. The transit time to the ileostomy was prolonged from 20 to 360 min. The loss of chloride and sodium was reduced. Clinical tolerance was good. This treatment allowed rapid weaning of parenteral nutrition and implementation of a constant rate enteral infusion with rapid nutritional restitution. Hospitalization was shortened and this treatment raises future opportunities in the short bowel syndrome.

Child, Preschool↗
PubMedDate not supplied

Genome-wide analysis of deoxyribonucleic acid in endometrial cancer using comparative genomic hybridization microarrays.

The aim of this study was to identify amplified oncogenes in endometrial cancer using array-based comparative genomic hybridization (array CGH). Despite its prevalence, the molecular mechanisms of endometrial carcinogenesis are still poorly understood. The selected array CGH allows the simultaneous examination of 58 oncogenes commonly amplified in human cancers and is capable of achieving increased mapping resolution compared with conventional CGH. A subset of 8 specimens from a bank of 60 malignant and normal specimens was selected for array analysis to identify potential genes of interest. TaqMan polymerase chain reaction was carried out on the 60 specimens to examine if aberrations at the genomic level correlated with gene expression and to compare expression in normal and malignant samples. Oncogenes amplified in the endometrial cancers included AR, PIK3CA, MET, HRAS, NRAS, D17S1670, FGFR1, CTSB, RPS6KB1, LAMC2, MYC, PDGFRA, FGF4/FGF3, PAKI, and FGR. Three genes were examined at the messenger RNA level. AR and PIK3CA were higher in normal specimens, and MET was higher in malignant samples, suggesting a role for MET in endometrial cancer. Newer arrays examining more genes and larger sample numbers are necessary to elucidate the carcinogenic pathway in endometrial cancer.

Adenocarcinoma↗