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Biomedical subjects

S E Rose

Publications and source records attributed to S E Rose.

36 records · Page 2Linked to original sources
PubMed1991

The visibility of the 1H NMR signal of ethanol in the dog brain.

In vivo, high-resolution, volume-selected 1H NMR spectroscopy was used to monitor the concentration of ethanol in the dog brain following intravenous injection of ethanol. Equilibration of ethanol in the body water should result in approximately equivalent concentrations of ethanol in the blood and brain. However, the mean equilibrium brain ethanol concentration determined using N-acetylaspartate as an internal standard was only 23 +/- 5% of the blood ethanol concentration. The disparity between blood and brain ethanol concentrations was attributed to underestimation of the ethanol concentration due to overlapping resonances with NAA and to T2 attenuation or possible nondetection of the 1H signal from ethanol bound at the surface of cell membranes and partitioned into the hydrophobic core of membrane lipids.

Animals↗
PubMed1991

A high-performance liquid chromatographic assay for the enantiomers of bevantolol in human plasma.

A method was developed and validated for the simultaneous analysis of (+)- and (-)-bevantolol in human plasma. The assay involves plasma protein precipitation, derivatization of racemic bevantolol to its diastereomeric thioureas with 2,3,4,5-tetra-o-acetyl-alpha-D-glucopyranosyl isothiocyanate, and solid-phase extraction of the diastereomers from 0.5 ml human plasma. Chromatographic separation was accomplished under isocratic conditions using a reversed-phase C-18 analytical column and mobile phase consisting of equal parts of 75 mM dibasic ammonium phosphate buffer (adjusted to pH 3.5 with phosphoric acid) and acetonitrile, with a detection wavelength of 220 nm. The absolute peak-height method was employed for quantitation. Retention times for the diastereomers of (+)- and (-)-bevantolol were 7.4 and 6.4 min, respectively. The method is suitable for the quantification of the enantiomers over a concentration range of 40 to 800 ng/ml per enantiomer.

Adrenergic beta-Antagonists↗
PubMed1990

High-field localized in vivo proton spectroscopy on micro volumes.

A water-suppressed volume-selected in vivo 1H spectrum of 0.2 ml of a rat brain has been obtained at 200 MHz using the SPACE localization method. Good signal-to-noise and spectral resolution were obtained by averaging 256 acquisitions. The spectrum shows little T2 weighting effect.

Animals↗
PubMed1990

In vivo volume-selective metabolite editing via correlated z-order.

Volume-selected 1H NMR spectroscopy was combined with spectral editing to selectively detect brain metabolites. The SPACE localization sequence was used to create a voxel of zeta-magnetization which could then be edited for any scalar coupled metabolite by the use of selective excitation in the ECZOTIC sequence to generate longitudinal spin order. The sequence returns an edited signal with no intrinsic loss of magnetization. The method was applied to observe approximately 10 mM ethanol and 17 mM lactate in the brain of a dog.

Animals↗
PubMed1990

Application of volume-selected, two-dimensional multiple-quantum editing in vivo to observe cerebral metabolites.

The volume selection technique SPACE has been combined with a two-dimensional multiple-quantum editing sequence to uniquely detect certain J-coupled cerebral metabolites. In vivo results demonstrating edited glutamate/glutamine and lactate from 0.4 ml of a rat's brain at 4.7 T are presented. The sequence was optimized to balance multiple-quantum generation and signal loss due to T2 relaxation. Without due regard to T2 relaxation little signal is observed.

Animals↗
PubMed1989

The effect of surface and internal electrodes on the gait of children with cerebral palsy, spastic diplegic type.

The purpose of this study was to determine whether surface and internal fine-wire electromyography electrodes had an effect on gait. The subjects for the experiments were 38 children with the spastic diplegic type of cerebral palsy. The children were filmed using the high-speed cinematographic technique while they walked (a) with no electrodes (unencumbered), (b) with only surface electrodes, and (c) with internal electrodes. Single stance time, step length, cadence, and walking velocity were compared with analysis of variance and Bonferroni t tests. The results included a significant decrease in cadence (-6.3% of unencumbered walking; p less than 0.05) when comparing walking with surface electrodes with walking without any electrodes. The internal electrodes caused significant decreases from normal walking in the following parameters: step length for both the measured leg (-18.6%; p less than 0.005) and the nonmeasured leg (-18.0%; p less than 0.005), cadence (-7.9%; p less than 0.02), and walking velocity (-23.5%; p less than 0.005). Internal electrodes caused significant decreases as compared with surface electrodes in the step length for both the measured leg (15.7%; p less than 0.01) and the nonmeasured leg (15.6%; p less than 0.005) and walking velocity (19.7%; p less than 0.005). Single stance phase did not change significantly in any of the comparisons. It appears that the addition of the surface electrode apparatus does change the normal gait of a subject, causing a large decrease in cadence. The measurement of gait with internal electrodes causes further change in gait, resulting in large decreases in step length and walking velocity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

In vivo high-resolution volume-selected proton spectroscopy and T1 measurements in the dog brain.

Successful in vivo NMR spectroscopy requires a combination of techniques to address the problems of volume selection, water suppression, and resolution. All this needs to be done in the very heterogeneous environment found in living organisms. Previously published techniques are used to obtain 1H spectra from a dog brain, observing metabolites with concentrations below 1 mM. Measurements of spin-lattice relaxation times (T1) are also presented. The 1H relaxation times are long (T1 greater than 1.0 s) yielding information about the fluidity of the molecular environment. Comments are made concerning the achievable linewidth in vivo and the deficiencies that phase-encoding spectroscopic methods may have in obtaining high-resolution 1H spectra.

Animals↗
PubMed1989

Inhibition of neutrophil locomotion, natural killer cell cytotoxicity and lymphocyte transformation by 1-methyl-3-phenyl-1,2,4-triazinium-5-olate, a novel triazinium zwitterion.

We studied a novel triazinium zwitterion compound for its effects on neutrophil locomotion and deoxyglucose uptake, Natural Killer (NK) cell cytotoxicity and mitogen-induced lymphocyte transformation. The results show significant inhibition of neutrophil locomotion at concentrations of 10 micrograms/ml or greater; by contrast, there was no significant effect on neutrophil deoxyglucose uptake. Significant suppression of NK cell cytotoxicity occurred at similar concentrations in a dose-dependent fashion. Marked suppression of mitogen-induced lymphocyte transformation was also observed for all three mitogens used in the assays. This effect was dose-dependent, reversible by washing and still evident even when it was added 37 h after the initiation of cultures. These results suggest that 1-methyl-3-phenyl-1,2,4-triazinium-5-olate may have application as an anti-inflammatory and immunosuppressive agent.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1979

Delta 9-tetrahydrocannabinol: elevation of absolute visual thresholds of rabbits.

The effect of Delta 9-tetrahydrocannabinol (THC) on the ability of rabbits to detect a minimal light stimulus (absolute visual threshold) was examined using the method of limits with an aversive classical conditioning paradigm. Both of two dosage levels of THC, similar to an amount ingested by a human from a single cigarette, significantly elevated the absolute visual threshold of all animals. Normal baseline thresholds, however, returned with 24 hours.

Animals↗
PubMedDate not supplied

Correlation between high-field T2-weighted MR imaging and histology of ischemic lesions in gerbil brain.

Global forebrain ischemia in the Mongolian gerbil is a common animal model for use in stroke research. We produced lesions of graded severity in gerbil brains (after prescreening by MR imaging) by performing 6-minute bilateral carotid artery occlusions while monitoring pericranial temperature with a temporalis muscle thermocouple probe and maintaining the temperature at 32 degrees C, 36 degrees C, or 40 degrees C. Lesion severity was scored 4 days after occlusion from findings on spin-echo images acquired at 7 T and from histologic scores. Statistically significant correlation was observed between the MR imaging score and brain temperature and between the MR imaging score and the area of the CA region of the hippocampus measured by histology. In addition, because prescreening with MR imaging revealed abnormalities in the hippocampus of some of the animals, and these animals were rejected from the study, the statistical significance of the result could be strengthened.

Animals↗
PubMedDate not supplied

A reproducible method for automated extraction of brain volumes from 3D human head MR images.

An automated method for extracting brain volumes from three commonly acquired three-dimensional (3D) MR images (proton density, T1 weighted, and T2-weighted) of the human head is described. The procedure is divided into four levels: preprocessing, segmentation, scalp removal, and postprocessing. A user-provided reference point is the sole operator-dependent input required. The method's parameters were first optimized and then fixed and applied to 30 repeat data sets from 15 normal older adult subjects to investigate its reproducibility. Percent differences between total brain volumes (TBVs) for the subjects' repeated data sets ranged from .5% to 2.2%. We conclude that the method is both robust and reproducible and has the potential for wide application.

Aged↗
PubMedDate not supplied

Application of high field localised in vivo 1H MRS to study biochemical changes in the thiamin deficient rat brain under glucose load.

In vivo, volume-selected 1H NMR spectroscopy employing the SPACE technique was used to monitor biochemical changes in the thiamin deficient rat brain in response to glucose loading. The concentrations of brain N-acetylaspartate, glutamate/glutamine/gamma-aminobutyric acid, lactate and glucose differed significantly from those of control animals. The results are consistent with a metabolic block at the reaction catalyzed by the thiamin dependent enzyme alpha-keto glutarate dehydrogenase soon after the onset of neurological symptoms of thiamin deficiency, and a further block at pyruvate dehydrogenase arising late in the course of thiamin deficiency.

Acidosis, Lactic↗
PubMedDate not supplied

Intentional occlusion of a transjugular intrahepatic portosystemic shunt.

The transjugular intrahepatic portosystemic shunt (TIPS) procedure is a well-described means of treating portal hypertension and its complications. Occasionally, the consequences of this shunt prompt the desire for its subsequent obliteration. We report one unsuccessful and one successful method of TIPS occlusion.

Aged↗
PubMedDate not supplied

1-Methyl-3-phenyl-1,2,4-triazinium-5-olate: a new zwitterion with cytotoxic activity against human cancer cell-lines.

One of 6 newly synthesized triazinium zwitterions (JR-1--JR-6) was shown to induce 51Cr-release from leukemic (HL60 and CEM) and solid tumor (MM170 and HeLa) cell-lines. Leukemic cells were more sensitive to this compound than solid tumors as demonstrated by dose-response and time-course studies. Other experiments showed that JR-6 (1-methyl-3-phenyl-1,2,4-triazinium-5-olate) significantly suppressed protein, RNA and DNA synthesis at tumoricidal concentrations.

Antineoplastic Agents↗
PubMedDate not supplied

Unique cellular features in a testicular plasmacytoma.

A case of testicular plasmacytoma is described at the light and fine structure level. The patient was a 54-year-old male with a history of multiple myeloma. The testicular tumor was restricted to an interstitial space growth. Plasma cells varied in differentiation with few obtaining the cartwheel nucleus and prominent Golgi of connective tissue plasma cells. Cytoplasmic inclusions were characteristic of most cells and a large number of intranuclear inclusions were present. To our knowledge, this is the first report of such inclusions in the cells of a testicular plasmacytoma. Their significance in cases of end stage myeloma is discussed.

Cell Nucleus↗