Our purpose was to develop temperature-sensitive MR sequences and image-processing techniques to assess their potential of monitoring interstitial laser therapy (ILT) in brain tumors (n = 3) and liver tumors (n = 7). ILT lasted 2 to 26 minutes, whereas images from T1-weighted fast-spin-echo (FSE) or spoiled gradient-recalled (SPGR) sequences were acquired within 5 to 13 seconds. Pixel subtraction and visualization of T1-weighted images or optical flow computation was done within less than 110 msec. Alternating phase-mapping of real and imaginary components of SPGR sequences was performed within 220 msec. Pixel subtraction of T1-weighted images identified thermal changes in liver and brain tumors but could not evaluate the temperature values as chemical shift-based imaging, which was, however, more affected by susceptibility effects and motion. Optical flow computation displayed the predicted course of thermal changes and revealed that the rate of heat deposition can be anisotropic, which may be related to heterogeneous tumor structure and/or vascularization.

Brain Neoplasms↗

PubMedDate not supplied

Neurochemical, endocrine and immunological responses to stress in young and old Fischer 344 male rats.

Two experiments were performed. In the first, a 20 min conditioned emotional response (CER) paradigm was used to compare the neurochemical, endocrine and immunological responses to stress of 7- and 22-month-old Fischer 344 (F344) male rats. In the second, corticosterone levels 20 min following ether stress, and regional brain type I and II corticosterone receptor densities were examined using 7- and 17.5-month-old F344 male rats. Dopamine (DA) metabolism in old nonstressed rats was significantly reduced in the medial frontal cortex, neostriatum, nucleus accumbens and hypothalamus, but not in the amygdala. The CER procedure, nevertheless, increased medial frontal cortical, nucleus accumbens and amygdaloid DA turnover in both the young and old rats. The young and old nonstressed rats did not evidence differences in norepinephrine (NE) and serotonin (5-HT) concentrations. However, stress resulted in a decrease in medial frontal cortical 5-hydroxyindoleacetic acid (5-HIAA) and hypothalamic 5-HT levels in old but not in young animals. These observations suggest age-related differences in the response of central NE and 5-HT systems to stress. Ether and the CER procedure led to exaggerated corticosterone responses in the old rats (17.5 and 22 month, respectively). Hippocampal type I but not type II corticosterone receptors were decreased by 47% in the 17.5-month-old rats. Thus, age-related changes in hippocampal corticosterone receptor types do not occur in unison, and the exacerbated corticosterone response to stress precedes the reported down-regulation of hippocampal type II corticosterone receptors in aged rats. Age-related changes were not observed in the concentrations of corticosterone receptors in other brain regions, or in the prolactin response to stress. The old rats, however, evidenced a reduction in the availability of the renin substrate, angiotensinogen, and in stress-induced renin secretion. Immune function was impaired in the old nonstressed rats, and further compromised by exposure to the CER procedure. In comparison to the young control rats, the old nonstressed rats showed an increased percentage of splenic large granular lymphocytes, reduced splenic natural killer cytotoxicity, and impaired Con-A-stimulated splenic T lymphocyte proliferation. Reductions in T splenic cell proliferation and natural killer cytotoxicity were observed in the young rats subjected to the CER paradigm, but not to the same extent as in the old rats. These observations indicate that aging male F344 rats evidence major alterations in basal central monoamine, endocrine and immune functions, and an increased sensitivity of these systems to stress.

Aging↗

PubMedDate not supplied

Computer-based imaging and interventional MRI: applications for neurosurgery.

Advances in computer technology and the development of open MRI systems definitely enhanced intraoperative image-guidance in neurosurgery. Based upon the integration of previously acquired and processed 3D information and the corresponding anatomy of the patient, this requires computerized image-processing methods (segmentation, registration, and display) and fast image integration techniques. Open MR systems equipped with instrument tracking systems, provide an interactive environment in which biopsies and minimally invasive interventions or open surgeries can be performed. Enhanced by the integration of multimodal imaging these techniques significantly improve the available treatment options and can change the prognosis for patients with surgically treatable diseases.

Biopsy↗

PubMedDate not supplied

Three-dimensional optical flow method for measurement of volumetric brain deformation from intraoperative MR images.

A three-dimensional optical flow method to measure volumetric brain deformation from sequential intraoperative MR images and preliminary clinical results from five cases are reported. Intraoperative MR images were scanned before and after dura opening, twice during tumor resection, and immediately after dura closure. The maximum cortical surface shift measured was 11 mm and subsurface shift was 4 mm. The computed deformation field was most satisfactory when the skin was segmented and removed from the images before the optical flow computation.

Adult↗

PubMedDate not supplied

Combination of ambulatory electrocardiographic monitoring and psychological testing in coronary artery disease patients.

Ambulatory electrocardiographic monitoring and psychological testing were performed in 100 patients with chronic stable myocardial infarction. These patients were divided into four groups according to their chest pain and transient ST-segment depression by Holter monitoring during the follow-up period: group A, 40 patients without complications; group B, 20 patients with silent myocardial ischemia; group C, 14 patients with episodes of chest pain alone; and group D, 26 patients with postinfarction angina. Whereas group B had silent myocardial ischemia and extroversion, groups C and D were characterized by introversion and neuroticism. The frequency of multi-vessel disease was 41% for group A, 53% for group B, 8% for group C and 70% for group D. The patients of group B not only received treatment for coronary artery disease but also behavioral counseling and those of group C received psychotherapy. The results support the view that a combination of Holter monitoring and psychological testing is clinically useful for the development of therapeutic strategies for coronary artery disease.

Aged↗

PubMedDate not supplied

Infective endocarditis of the tricuspid valve in a non-drug user.

A case of infective endocarditis of the tricuspid valve is described in a young female patient with no history of intravenous drug abuse. The patient suffered from symptoms of septic emboli of the lung and right heart failure. She was ultimately treated by tricuspid valve replacement. There was no recurrence of symptoms following surgery.

Adult↗

PubMedDate not supplied

Radical modulation activity of pine cone extracts of Pinus elliottii var. Elliottii.

The radical modulation activity of lignins prepared from the cone of Pinus elliottii var. Elliottii was investigated, using ESR spectroscopy. These lignins produced radical(s) under alkaline conditions, and the radical intensity was increased with increasing pH. Lower concentrations of lignins slightly reduced the radical intensity of sodium ascorbate, whereas higher concentrations of lignins enhanced both the radical intensity and cytotoxic activity of sodium ascorbate. Lignins effectively scavenged superoxide anion, produced by hypoxanthine-xanthine oxidase reaction. Elliottii lignins significantly inhibited the human immunodeficiency virus (HIV)-induced cytopathic effect, in similar fashions to other natural, commercial and synthetic lignins. Pretreatment of mice with lignins significantly protected them from the lethal infection with E. coli. Crude alkaline extracts of Elliottii pine cone displayed similar magnitude of activity with lignins. These data further supports the medicinal efficacy of plant extracts.

Animals↗

PubMedDate not supplied

Application of membrane filters for spectrophotometric determination of cationic surfactants in river water and sediment.

Cationic surfactant (CS+) in urban river water and sediment was extracted and determined spectrophotometrically with 2 membrane filters. The CS+ in the water samples, mostly in the form of an ion associate with the coexisting anionic surfactant (AS), was collected on a polytetrafluoroethylene (PTFE) membrane filter and eluted with methanol. Bromphenol blue (BPB), hydrochloric acid, and water were added to the methanol solution successively, and the mixed solution was filtered through a mixed cellulose ester membrane filter. The CS+-BPB- ion associate, formed by a counter ion exchange, was collected on the filter and dissolved into N,N-dimethylformamide (DMF) together with the mixed cellulose ester membrane filter. After addition of 2 drops of triethanolamine, the absorbance of the DMF solution was measured. The CS+ in sediment samples was extracted with methanol by ultrasonic irradiation; the methanol solution was then passed through a PTFE membrane filter and evaporated to dryness. The CS+ was redissolved in a small amount of methanol. For water samples, recoveries and relative standard deviations for 0.30 microM benzyldimethyl-tetradecylammonium ion, a standard material, were > or =93 and < or =5%, with a detection limit of 0.02 microM. Concentrations of CS+ in sediments were much higher than those in water samples, indicating that CS+ is adsorbed on the surface of the sediment.

Adsorption↗

PubMedDate not supplied

Stimulation of granulocytic cell iodination by tannins and related compounds.

Tannic acid stimulated the iodination (incorporation of radioactive iodine into an acid-insoluble fraction) of human peripheral blood polymorphonuclear cells (PMN) and human promyelocytic leukemic HL-60 cells, without affecting the iodination of 9 other cultured cell lines. The stimulation of both PMN and HL-60 cells depended on incubation time and temperature, and was significantly suppressed by myeloperoxidase inhibitors. Among chemically defined natural polyphenols, condensed tannins (epicatechin gallate oligomers) and monomeric and oligomeric hydrolyzable tannins potently stimulated PMN iodination, whereas polyphenols of lower molecular weight (gallic acid, alkyl gallates, epicatechin, epicatechin gallate, epigallocatechin, caffeic acid derivatives and licorice flavonoids) had much less activity. Various synthetic polyphenolic compounds structurally unrelated to tannins also stimulated PMN iodination depending upon their molecular weight, but to a slightly lesser extent. The results suggest that the stimulation activity of tannins and related polyphenols might depend more on their molecular weights than the number of hydroxyl groups on each benzene ring in the molecule, or the presence of sugars or hexahydroxydiphenoyl groups.

Animals↗

PubMedDate not supplied

Chemical modification potentiates paramylon induction of antimicrobial activity.

Induction of antimicrobial activity by two water-insoluble polysaccharides, paramylon and TAK, was significantly potentiated by introduction of positively charged groups (such as N,N-dimethylaminoethyl; N,N-diethylaminoethyl; and 2-hydroxy-3-trimethylammoniopropyl), but not by introduction of negatively charged groups (such as carboxymethyl or sulfate). Cross-linking of these derivatives with epichlorohydrin did not increase their potentiating activity. The effects of these derivatives did not always correlate with their ability to accumulate polymorphonuclear cells and to stimulate the generation of luminol-dependent chemiluminescence by peritoneal exudate cells.

Animals↗

PubMedDate not supplied

Inhibition of herpes simplex virus infection by pine cone antitumor substances.

Several antitumor substances extracted from cones of various pine trees inhibited the plaque formation of Herpes simplex virus types 1 and 2 (HSV-1, HSV-2) strains in African green monkey kidney cells and human adenocarcinoma cells. The 50% effective dose of the most active fraction, Fr. VI (0.3 micrograms/ml) was 0.001 times its 50% cytotoxic dose (greater than 300 micrograms/ml). The anti-HSV activity of various pine cone extracts increased with their acidity. Identification of the polyphenol groups as donors of the acidity was further supported by the observation that the anti-HSV activity of the natural polyphenolic products, such as tannin and lignin, significantly exceeded that of other natural or chemically modified antitumor polysaccharides. An experiment using radiolabeled virus particles indicated that the anti-HSV effect of both Fr. VI and lignin was attributable to interference with virus adsorption to these cells rather than to inhibition of virus penetration into the cells.

Animals↗

PubMedDate not supplied

Mitogenic activity of pine cone extracts against cultured splenocytes from normal and tumor-bearing animals.

An acidic pine cone extract, Fr. V. of Pinus parviflora Sieb. et Zucc. significantly stimulated DNA synthesis of isolated splenocytes from both mice and rats, but only marginally affected the DNA synthesis of leukemic cell lines. The maximum stimulation level attained by Fr. V slightly exceeded that of plant lectins, whereas much weaker stimulating activity was found in natural and chemically modified antitumor polysaccharides, sialic acid-rich glycoproteins, and polyphenolic compounds such as lignin and tannic acid. In mice with subcutaneously transplanted sarcoma-180, responses of splenocytes against Con A declines in the terminal stage of tumor development, whereas responses against Fr. V remained relatively constant throughout all periods of tumor progression. The suppression of Fr. V activity by acetylation or methylation suggests the importance of the hydroxyl group in the expression of its stimulation activity.

Animals↗

PubMedDate not supplied

[Proceedings: 303. The effect of the fastigial pressor response on ADH secretion (author's transl)].

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Animals↗