Medetomidine, atipamezole and midazolam in pig plasma were determined by liquid chromatography-mass spectrometry (LC-MS) with an atmospheric pressure chemical ionization interface system by the use of detomidine as an internal standard. The method was applied to studies of pharmacokinetic behaviour of these drugs.

Adrenergic alpha-Agonists↗

PubMedDate not supplied

Inhibitory postsynaptic current in the crayfish muscle.

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Animals↗

PubMedDate not supplied

Neurologic sequelae and MRI in low-birth weight patients.

Periventricular hyperintensity was detected using long repetition and echo time on spin-echo magnetic resonance imaging in 24 of 32 children with birth weights less than 2,500 gm. Functionally, 11 children were normal, 6 mildly handicapped, 7 moderately handicapped, and 8 severely handicapped. The functional handicaps were correlated to the degree of periventricular hyperintensity observed on magnetic resonance imaging when periventricular hyperintensity was divided into 4 grades; therefore, the extent of periventricular hyperintensity observed on magnetic resonance imaging has been proved to be of value in the clinical assessment of low-birth weight infants and children and may contribute to the prediction of later functional deficits.

Brain Diseases↗

PubMedDate not supplied

Highly active analogs of 1alpha,25-dihydroxyvitamin D(3) that resist metabolism through C-24 oxidation and C-3 epimerization pathways.

The secosteroid hormone 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)] is metabolized in its target tissues through modifications of both the side chain and the A-ring. The C-24 oxidation pathway, the main side chain modification pathway is initiated by hydroxylation at C-24 of the side chain and leads to the formation of the end product, calcitroic acid. The C-23 and C-26 oxidation pathways, the minor side chain modification pathways are initiated by hydroxylations at C-23 and C-26 of the side chain and lead to the formation of the end product, calcitriol lactone. The C-3 epimerization pathway, the newly discovered A-ring modification pathway is initiated by epimerization of the hydroxyl group at C-3 of the A-ring to form 1alpha,25(OH)(2)-3-epi-D(3). A rational design for the synthesis of potent analogs of 1alpha,25(OH)(2)D(3) is developed based on the knowledge of the various metabolic pathways of 1alpha,25(OH)(2)D(3). Structural modifications around the C-20 position, such as C-20 epimerization or introduction of the 16-double bond affect the configuration of the side chain. This results in the arrest of the C-24 hydroxylation initiated cascade of side chain modifications at the C-24 oxo stage, thus producing the stable C-24 oxo metabolites which are as active as their parent analogs. To prevent C-23 and C-24 hydroxylations, cis or trans double bonds, or a triple bond are incorporated in between C-23 and C-24. To prevent C-26 hydroxylation, the hydrogens on these carbons are replaced with fluorines. Furthermore, testing the metabolic fate of the various analogs with modifications of the A-ring, it was found that the rate of C-3 epimerization of 5,6-trans or 19-nor analogs is decreased to a significant extent. Assembly of all these protective structural modifications in single molecules has then produced the most active vitamin D(3) analogs 1alpha,25(OH)(2)-16,23-E-diene-26,27-hexafluoro-19-nor-D(3) (Ro 25-9022), 1alpha,25(OH)(2)-16,23-Z-diene-26,27-hexafluoro-19-nor-D(3) (Ro 26-2198), and 1alpha,25(OH)(2)-16-ene-23-yne-26,27-hexafluoro-19-nor-D(3) (Ro 25-6760), as indicated by their antiproliferative activities.

Animals↗

PubMedDate not supplied

Feasibility of a nickel-metal hydride battery for totally implantable artificial hearts.

An implantable rechargeable battery is one of the key technologies for totally implantable artificial hearts. The nickel-metal hydride (Ni-MH) battery is promising for its high energy density of 1.5-2.0 times that of a nickel-cadmium battery. In this study, the effects of pulsatile discharge loads on the operating time and cycle life of Ni-MH batteries at 39 degrees C were studied. Two battery cells (TH-3M, 1,200 mAh, phi 14.5 x 49 mm; Toshiba, Tokyo, Japan) in series were charge/discharge cycled at 39 degrees C using a charge current of 1CA (1,200 mA) and then were fully discharged to 1.0 V/cell under either pulsatile discharge loads, which mimicked a systole (1 A for 0.3 sec) and a diastole (0.4 A for 0.3 sec), or a non pulsatile discharge load equivalent to the average of the pulsatile loads (0.7 A). Each cycle life test was interrupted on the 482nd cycle under pulsatile load, and on the 423rd cycle under non pulsatile load, because of malfunction of each battery charger. The tests showed that the pulsatile discharge cells had significantly (p < 0.001) less operating time (74.0 +/- 7.15 min) throughout the test period (up to 482 days) compared to the cells under equivalent non pulsatile discharge loads (93.7 +/- 7.74 min). The pulsatile-discharged Ni-MH cells provide significantly less operating time than the constantly discharged cells; the Ni-MH battery has an operating time of over 78 min and a cycle life of almost 500 cycles at 39 degrees C. In conclusion, the Ni-MH battery is feasible as an implantable back-up battery for a totally implantable artificial heart system.

Electronics, Medical↗

PubMedDate not supplied

Magnetic resonance imaging of the lateral ventricles in beagle-type dogs.

Magnetic resonance (MR) imaging was performed on 21 presumed normal Beagle-type dogs. The size and symmetry of their lateral ventricles were evaluated and dogs were categorized on the basis of the percentage of their ventricular height (Vh) to brain height (Bh) and the ratio of the largest to the smallest ventricular area (rVA). Eleven dogs had lateral ventricles classified as normal sized (0-14% Vh/Bh) while 10 of 21 dogs had moderate enlargement (15-25% Vh/Bh) of one or both lateral ventricles. None of the dogs had severe lateral ventricular enlargement. Degree of asymmetry was also arbitrarily categorized on basis of rVA as normal to minimal (rVA < 1.5), mild (1.5 < rVA < 2.0), or severe (2.0 < rVA). Of the dogs having normal-sized lateral ventricles, six of eleven had symmetric, three of eleven had mildly asymmetric and two of eleven had severely asymmetric lateral ventricles. Of the dogs having at least one moderately enlarged lateral ventricles, five of ten had symmetric lateral ventricles, and two of ten had mild asymmetry and three of ten had severe asymmetry. Gender and body weight had no statistical relationship to lateral ventricle symmetry. Clinically insignificant ventricular enlargement and asymmetry was common in this group of Beagle dogs.

Animals↗

PubMedDate not supplied

Appearance of canine abdominal tumors with magnetic resonance imaging using a low field permanent magnet.

The study was carried out to evaluate the applicability of magnetic resonance imaging (MRI) in detecting tumors in the abdomen of the dog. Abdominal ultrasound and MRI were performed on 8 dogs having a mass lesion on abdominal radiography. MR images were obtained in the transverse, sagittal and dorsal planes using T1- and T2-weighted spin echo pulse sequences. There was good visual correlation of the lesion site by MRI and ultrasonography (US).

Abdomen↗

PubMedDate not supplied

A clinicopathologic study of focal segmental glomerulosclerosis: comparison between nephrotic and non-nephrotic focal segmental glomerulosclerosis.

Seven out of 16 patients with primary focal segmental glomerulosclerosis (FGS) did not showed the nephrotic syndrome throughout their clinical courses, and then patients with FGS could be divided into the two groups, nephrotic FGS group (NS-G) and non-nephrotic one (NO-G). The clinicopathologic findings of NS-G and NO-G were compared retrospectively to define the pathogenesis of the glomerular disease in FGS. No significant differences were found between the groups except for proteinuria and serum total protein or albumin, and it was impossible to distinguish the two groups only histologically. In addition, electron microscopic study revealed that the glomerular epithelial cell was altered more than the endothelial and mesangial cells in both groups, resulting in vacuolization, foot process fusion, and detachment, and the striking fact that the glomerular epithelial vacuoles consisted mainly of the dilated rough endoplasmic reticulums (RERs). The speculation is drawn that in FGS the glomerular epithelial cell is firstly damaged by unknown factor(s), manifested functionally proteinuria and/or hematuria, morphologically dilatation of RER, foot process fusion, detachment, and eventually segmental sclerosis and hyalinosis.

Adolescent↗

PubMedDate not supplied

Minor changes in regional cerebral blood flow revealed by the early distribution of I-123 IMP in brain.

To evaluate the early distribution of I-123 IMP in the brain, 10 dynamic images were obtained in the first 10 minutes after injection using a ring-type SPECT system with a high-sensitivity collimator. In cases of chronic carotid occlusion without brain CT abnormalities, areas of low perfusion were more clearly demonstrated in dynamic images than in static images obtained beginning 20 minutes after injection and continuing for 15 minutes using a high-resolution collimator. In cases of hyperperfusion following infarct or surgery, there was a difference between dynamic and static images in the visualization of hyperemic lesions. The distribution of I-123 IMP in the brain changes gradually, even in the early period after injection, and evaluation of early accumulation is useful for the detection of minor changes in regional cerebral blood flow.

Aged↗

PubMedDate not supplied

Coronary-subclavian steal corrected with percutaneous transluminal angioplasty.

We describe a case of coronary-subclavian steal syndrome treated with percutaneous transluminal angioplasty. A 58-year-old female who had her first coronary bypass operation 6 years previously and a second operation 3 years previously involving the left internal mammary artery and right gastroepiploic artery, developed unusual angina on effort characterized by left precordial pain, pain in the left shoulder and arm, tinnitus and dizziness. Angiography revealed retrograde flow to the left subclavian artery via the left vertebral artery and left internal mammary artery. Severe stenosis of the left subclavian artery was demonstrated at its ostium. Restoration of antegrade flow to the vertebral artery and left internal mammary artery by transluminal angioplasty resulted in complete resolution of these symptoms.

Angina Pectoris↗

PubMedDate not supplied

Improvement in Fourier analysis of gated blood-pool studies using single photon emission computed tomography: methodology and clinical feasibility.

We have developed a new method for obtaining reconstructed left ventricular (LV) planar images acquired from multidirectional views using gated blood-pool single photon emission computed tomography (SPECT), and have applied Fourier analysis to these planar images. In this paper, we describe the methodology of our new technique and discuss its feasibility for the detection of LV wall motion abnormalities (WMA) in patients with coronary artery disease (CAD). Sagittal long-axis, horizontal long-axis and short-axis sections of the LV were generated from the reconstructed transaxial tomograms. Sections covering only the LV at the same phase of the cardiac cycle were added to reconstruct planar images. Fourier analysis was then performed to construct phase and amplitude images. In 42 patients with significant WMA, a comparative study concerning the detection of WMA was performed between conventional and SPECT methods. The SPECT method had greater sensitivity in all segments of the LV, with no significant loss in specificity. In particular, the sensitivity of the SPECT method was significantly greater than that of the conventional method for inferior and posterior WMA (91% vs 57%; and 76% vs 35%, respectively). The method described here shows greater clinical effectiveness for the detection of LV WMA in patients with CAD.

Adult↗

PubMedDate not supplied

Increased serum alkaline phosphatase activity in Behçet's disease.

Raised serum alkaline phosphatase (Al-P) levels were found in 23 of 213 patients (10.8%) with Behcet's disease (BD). Al-P isoenzyme studies showed an increased liver fraction. Increased Al-P levels were well correlated with the erythrocyte sedimentation rate (ESR) and C reactive protein (CRP). It is concluded that Al-P is a good indicator for the activity of BD.

Adult↗

PubMedDate not supplied

Intraoperative ultrasonic imaging of coronary artery and saphenous vein grafts in coronary bypass surgery.

The intraoperative evaluation of native coronary atherosclerotic lesions and the anastomotic status of saphenous vein grafts were made using two-dimensional echography. Ultrasonic imaging was performed with a linear cross-sectional ultrasonograph and a high-frequency wide-brand microtransducer. In animal experiments, the lumens of the left main trunk and other major branches of coronary arteries of mongrel dogs were clearly visualized; the stenotic portion created by external constriction of the left anterior descending artery was also recognized in this manner. In the clinical application, 30 patients who required coronary artery this manner. In the clinical application, 30 patients who required coronary artery bypass grafting were examined during surgery. Intraluminal status of the left main trunk and proximal to mid portion of the other major coronary arteries were visualized satisfactorily. Stenotic portions detected by preoperative coronary cine-angiography were recognized. It was concluded that intraoperative echo coronary arteriography provides adequate information on the target coronary artery before the incision is made and that evaluation of anastomotic status is possible.

Animals↗

PubMedDate not supplied

Aortic regurgitation caused by giant cell aortitis.

A case of giant cell aortitis causing aortic regurgitation is reported. The aortic valve was replaced with a Medtronic-Hall prosthesis. The patient has been followed for seven months, during which time she received steroid therapy. There was good evidence of hemodynamic correction, but no evidence of further progress in the arteritis has been noted. The pathological and clinical problems of this disease are discussed.

Adult↗