Contrast-enhanced MRA for investigation of cerebral arteriovenous malformations.

We evaluated contrast-enhanced MRA (enhanced 3-D fast gradient-echo [efgre3d] with spectral inversion recovery) for identification of 15 intracranial arteriovenous malformations (AVMs) in 14 patients. Demonstration of the feeding arteries was classified as good for 16 examinations on maximum-intensity projections and multiprojection volume reconstruction images. The nidus was seen well in all patients. Definition of the draining veins was good or fair except for one poor result. Therapeutic effects were clearly demonstrated in three follow-up series. Contrast-enhanced MRA using efgre3d is useful for delineation of AVMs and for follow-up after treatment.

Epidural spinal cord stimulation for the treatment of painful legs and moving toes syndrome.

A case of 51-year-old male with painful legs and moving toes syndrome was successfully treated with epidural spinal cord stimulation. He was previously treated with varieties of medication, epidural block, transcutaneous nerve stimulation, lumbar sympathetic block, with no or only a transient effect. Epidural spinal cord stimulation was applied by means of percutaneously inserted epidural electrodes connected to a percutaneous extension for 2-week test stimulation period and later to a permanent device (ITREL). Pain and involuntary movement were relieved almost completely during the stimulation and the effect was still evident 6 months later.

Pharmacological effect of tamsulosin in relation to dog plasma and tissue concentrations: prostatic and urethral retention possibly contributes to uroselectivity of tamsulosin.

In the present study the pharmacokinetics and pharmacodynamics of tamsulosin were investigated in anesthetized male dogs. Hypogastric nerve stimulation elevated the intraurethral pressure (IUP), which was inhibited dose dependently by intraduodenal administration of tamsulosin (3-30 microg/kg). The inhibition peaked about 90 min after dosing and lasted up to 240 min. The basal mean blood pressure did not change significantly during the observation period. The plasma, prostatic, and urethral concentrations of tamsulosin were determined by the liquid chromatography-mass spectrometry/mass spectrometry method. The plasma concentration reached the maximal level within 30 min after dosing and gradually declined thereafter. The maximal total plasma concentration of tamsulosin (C(max, t)) and its unbound concentration (C(max, u)) correlated with the maximal effect on IUP response [r(2) = 0.81 (p<0.01, n = 15) and r(2) = 0.84 (p<0.01, n = 15), respectively]. Each individual unbound plasma concentration did not correlate, however, with its associated inhibition of IUP response (r(2) = 0.04, n = 126). Although the plasma concentration of tamsulosin decreased nearly to the lower limit of quantitation 240 min after dosing, the prostatic and urethral concentrations remained high, i.e., 13 to 44 times greater than the plasma concentration. Our data demonstrate that the maximal inhibition by tamsulosin of IUP response is well correlated with the maximal plasma concentration in the early phase. The sustained effect of tamsulosin on IUP response that follows may be related to prostatic and urethral retention of tamsulosin.

Pharmacological profile of nicardipine hydrochloride in anesthetized dogs with acute heart failure. Part 1: Hemodynamic effects in normal dogs and dogs with acute heart failure.

Cardiovascular effects of nicardipine hydrochloride (NIC, CAS 54527-84-3, Perdipine), a calcium channel blocker, were investigated in anesthetized normal dogs and dogs with acute heart failure (AHF), and compared with those of nitroglycerin (NTG). In open-chest anesthetized dogs, NIC (0.1-10 micrograms/kg/min i.v.) dose-dependently increased cardiac output (CO) and coronary blood flow as well as decreased mean blood pressure (MBP). NIC had no effect on heart rate (HR) or maximum rate of rise of left ventricular pressure (max. dp/dt). In contrast (0.1-10 micrograms/kg/min i.v.) decreased MBP, but did not change the other cardiovascular parameters. NIC and NTG did not prolong PQ, QRS or QTc intervals. In addition, NIC was effective in the presence of dobutamine. In the anesthetized dog model of ischemic AHF induced by coronary ligation, and ischemia/angiotensin II-induced AHF, NIC (1 and 3 micrograms/kg/min i.v.) increased CO and stroke volume, and reduced total peripheral resistance without decreasing HR or cardiac contractility. Furthermore, in the ischemia/angiotension II-induced AHF model, NIC decreased left ventricular end-diastolic pressure (LVEDP). In contrast, NTG (1-10 micrograms/kg/min i.v.) decreased LVEDP in both AHF models; but did not increase CO. These results suggest that NIC improves hemodynamics in dogs with AHF mainly by reducing afterload without adversely affecting the cardiac contractility or conduction system, while NTG exerts its effect on AHF by reducing preload. NIC injection would thus appear to be beneficial in the treatment of AHF.

Pharmacological profile of nicardipine hydrochloride in anesthetized dogs with acute heart failure. Part 2: Effect on myocardial metabolism.

The effect of nicardipine hydrochloride (NIC, CAS 54527-84-3, Perdipine) on myocardial metabolism was investigated in an experimental model of ischemic acute heart failure (AHF) induced by coronary ligation in anesthetized dogs. The left anterior descending and/or circumflex coronary ligation decreased coronary sinus blood flow (CBF), maximum rate of rise of left ventricular pressure (max. dp/dt), cardiac output (CO) and stroke volume (SV), and increased left ventricular end-diastolic pressure, indicating the development of AHF. In this ischemic AHF model, NIC (3 micrograms/kg/min i.v. infusion for 15 min) increased CBF, CO and SV, and reduced systemic and coronary artery resistances, resulting in the improvement of AHF. During the effective period, NIC decreased myocardial oxygen consumption and the coronary arterio-venous difference of oxygen content, carbon dioxide pressure and pH. At the same time, NIC did not decrease the lactate extraction. These results suggest that NIC improves hemodynamics and the balance of myocardium oxygen supply and demand in dogs with AHF by means of reducing afterload and dilating coronary artery.

Internal structure of the temporomandibular joint and the circumferential bone: comparison between dentulous and edentulous specimens.

To clarify changes in the trabecular structure due to loss of the teeth, the author compared soft X-ray images and morphological measurement values of the mandibular condyle and articular eminence between dentulous and edentulous specimens. The center of the skull base containing the temporomandibular joint was removed along the Frankfort horizontal and median sagittal planes. A block in the center of the cranial base was rejected using the Frankfort horizontal plane and median sagittal plane as references. The specimens were embedded in polyester resin by the routine method. The hardened specimens were horizontally cut into 500 microns sections and photographed using soft X-ray films. Soft X-ray of each section was taken for observation by naked eye and morphometry by computer. Observation of the compact bone in the articular eminence showed thinner compact bone on the posterior slope of the articular eminence, which is a functional plane, than on the anterior slope of the articular eminence. There was a trabecular bone group on the lateral area running from the compact bone on the posterior surface of the articular eminence into the zygomatic arch and a thick trabecular bone group in a network pattern on the medial area. In the central area of the mandibular condyle, spongy bone was surrounded by oval compact bone, and the internal trabecular bone ran anteromedially in nearly the same pattern as the arrangement of the lateral pterygoid muscle. At all sites, the density, width, extent, and index indicating the complexity of the trabecular bone had higher values in dentulous specimens than in edentulous specimens.

Effect of YM934, a KATP channel opener, on airway hyperresponsiveness induced by platelet activating factor in guinea-pigs.

The effect of YM934 (2-(3,4-dihydro-2,2-dimethyl-6-nitro-2H-1, 4-benzoxazin-4-yl)pyridine N-oxide) on airway hyperresponsiveness induced by platelet activating factor (PAF) was investigated in anesthetized guinea-pigs. Bronchoconstrictor responses to histamine were enhanced by intravenous (i.v.) infusion of PAF (600 ng/kg/h for 1 h). The KATP channel opener, YM934 (10-100 micrograms/ kg), given by i.v. bolus injection or i.v. infusion (75 min) dose-dependently inhibited this PAF-induced airway hyperresponsiveness. In the normal control group, i.v. bolus injection of YM934 dose-dependently reduced the bronchoconstrictor responses to histamine. However, i.v. infusion of YM934 (100 micrograms/kg) had almost no effect on responsiveness. Pretreatment with capsaicin (50 micrograms/kg, s.c.), a depleter of neuropeptides, partially prevented the development of PAF-induced airway hyperresponsiveness. In contrast, phosphoramidon (2.5 mg/kg, i.v.), an inhibitor of neutral endopeptidase, enhanced the airway hyperresponsiveness induced by PAF. Furthermore, YM934 inhibited PAF-induced airway hyperresponsiveness in guinea-pigs pretreated with capsaicin or phosphoramidon. The present results suggest that YM934 given by i.v. infusion reduces PAF-induced airway hyperresponsiveness at doses insufficient to produce a bronchodilatory effect. Further, the mechanism of YM934's inhibitory effect on airway hyperresponsiveness may involve bronchodilatory and other unidentified effects, such as a decrease in the release of neuropeptides from sensory nerve terminals.

An anatomical study of a muscle bundle separated from the medial pterygoid muscle.

When mandibular dentures are fabricated, marginal sealing should be taken into consideration for the stability of the denture. We selected specimens of the medial pterygoid muscle showing insertion of an independent small muscle bundle at its insertion site, and evaluated the anatomical relationship between the morphology of the insertion site and the denture. The insertion of the pterygoid muscle was classified according to the insertion morphology of the independent small muscle bundle into three types using the retromolar pad as a reference: Type I, insertion of the independent muscle bundle posterior to the retromolar pad; Type II, insertion immediately below the retromolar pad; and Type III, insertion into the fascia of the mylohyoid muscle. Types II and III muscles seem to affect the denture because of their closeness to the mandibular denture. In the oral cavity, the independent small muscle bundle studied appeared as a streak-like structure. When such a structure is detected during examination for denture fabrication, the following consideration is necessary. Since the medial pterygoid muscle is a mouth-closing muscle, this independent small muscle bundle may contract during mouth closing, appearing more markedly in the oral cavity. Therefore, examination should be performed not only with the mouth closed but also with assumed centric occlusion.

Effect of YM934, a novel potassium-channel opener, in various experimental asthma models in guinea-pigs.

YM934 is a novel synthetic potassium-channel opener. We have investigated its anti-asthma effect after intravenous (i.v.) and oral (p.o.) administration in various experimental asthma models in the guinea-pig, and compared the results with those for lemakalim, theophylline and salbutamol. In an ovalbumin-active sensitization anaphylaxis asthma model, YM934, lemakalim, theophylline and salbutamol dose-dependently prolonged the time before the occurrence of asthma attacks and reduced the mortality rate. The respective ED50 values (dose required to prolong by 50% the time before the occurrence of attacks) of the anti-asthma effects of YM934, lemakalim, theophylline and salbutamol were 6, 340, 30000, and 45 micrograms kg-1 (i.v.); the efficacy ratios were YM934 (1) > salbutamol (1/9) > lemakalim (1/57) > > theophylline (1/5000). YM934 also prolonged the period before the occurrence of attacks in the anti-BSA (bovine serum albumin) serum-passive sensitization anaphylaxis, histamine-induced and methacho-line-induced asthma models, with respective ED50 values for these models of 15, 22 and 20 micrograms kg-1 (i.v.). Among these models a reduction in mortality rate was seen in the histamine- and methacholine-induced asthma models. After oral administration, YM934 showed an anti-asthma effect in the ovalbumin-active sensitization anaphylaxis, histamine-induced and methacholine-induced asthma models, with respective ED50 values of 38, 44 and 193 micrograms kg-1. YM934 was 5-6 times more potent than salbutamol. These results indicate that YM934 has potent anti-asthma activity, and that this activity is mainly attributable to bronchodilation, most likely mediated through its potassium-channel opening activity.

Artificial parthenogenesis in starfish eggs: behavior of nuclei and chromosomes resulting in tetraploidy of parthenogenotes produced by the suppression of polar body extrusion.

Artificial parthenogenesis in starfish requires the activation of oocytes and the suppression of the polar body (PB) extrusion. To induce parthenogenesis we have employed a combination of calcium ionophore A23187 for activating oocytes and cytochalasin B (CB) for the suppression of PB extrusions. The treatment of activated oocytes with CB during meiosis I produced eggs lacking polar bodies, i.e., during meiosis I produced eggs lacking polar bodies, i.e., 0pb eggs, and treatment during meiosis II induced eggs bearing the first PB only, i.e., 1pb eggs. About 90% of both 0pb and 1pb eggs developed parthenogenetically with strong synchrony of cell division among eggs. After meiotic chromosomes in CB-treated oocytes separated finally into monads, they came together to form a single nucleus. The nucleus was found to be tetraploid in the 0pb eggs and diploid in the 1pb eggs. Regardless of the difference in ploidy, both 0pb and 1pb eggs developed as tetraploid embryos. Observations of the behavior of meiotic chromosomes and nuclei revealed that in the 0pb eggs, the first round of chromosomal replication was followed by the first cleavage, as in normally fertilized eggs. In the 1pb eggs, on the other hand, two rounds of chromosomal replication were found to precede the first cleavage, indicating the occurrence of one (first) round of chromosomal replication that is not accompanied with cytokinesis. In the first round of mitosis, a bipolar spindle did not appear, but only a half spindle was formed, resulting in the failure of both karyokinesis and cytokinesis. Thus, both types of parthenogenetic eggs became tetraploid before the first cleavage. At the first cleavage, both types of eggs formed a bipolar spindle and divided into a pair of blastomeres. Based on these observations, we suggest that the meiotic centrosomes remaining in these eggs by the failure of PB extrusion are diverted into mitosis-organizing centers in the mitotic spindle, and this results in parthenogenetic development.

An autopsy case of tuberous sclerosis. Histological and immunohistochemical study.

We report an autopsy case of tuberous sclerosis. A 19-year-old Japanese man had shown facial adenoma sebaceum, intractable convulsive seizures and severe mental retardation. Gross inspection of the brain showed a cortical tuber from the orbital frontal lobe to the rhinencephalon of the left side and a few subependymal nodules. Histological examination revealed many cortical tubers in the cerebral hemispheres, a few subependymal nodules with calcification and multifocal clusters of heterotopic cells in the white matter (white matter nodules). In these lesions, massive giant cells with abundant eosinophilic cytoplasm and without Nissl substances were found. Although the size and shape of the giant cells were variable, the majority of them were gemistcytic, ovoid or polygonal. Immunohistochemistry was employed in these lesions using antibodies against neurofilament protein (NFP), glial fibrillary acidic protein (GFAP), vimentin (VM) and myelin basic protein (MBP). In the cortical tuber, the majority of the giant cells were positive for both NFP and VM, but a few were positive for GFAP. All of them were negative for MBP. In the subependymal nodule and white matter nodule, the majority of the giant cells were positive for NFP, but a few were positive for VM, and none were positive for either GFAP and MBP. These findings suggest that the majority of the giant cells may be immature cells toward neuronal series and a few may be those toward astroglial series. These findings also indicate that the giant cells in the subependymal nodule and white matter nodule may be more differentiated than those in the cortical tuber. The nature of the giant cells in tuberous sclerosis is discussed.

Stably Sustained Hydrogen Production with High Molar Yield through a Combination of a Marine Green Alga and a Photosynthetic Bacterium.

Stably sustained continuous production of hydrogen with high molar yield was achieved through a combination of dark fermentative hydrogen evolution by Chlamydomonas sp. strain MGA161 and hydrogen photoevolution by a marine photosynthetic bacterium W-1S in an alternating light-dark cycle as a model of the day-night cycle. The newly isolated strain W-1S could use acetic acid and ethanol excreted by strain MGA161 as electron donors for hydrogen photoevolution. The fermentation broth of strain MGA161 stimulated the hydrogen photoproduction of strain W-1S. This alga-bacterial combination had a high conversion yield of 8 mol H2/mol of glucose of starch, with the possibility of improvement up to 10.5.

[A clinical comparison between 111In labeled leukocyte and 67Ga scintigraphy in acute and chronic inflammatory diseases].

111In labeled leukocyte scintigraphy (ILLS) and 67Ga scintigraphy (67Ga) were carried out in 56 patients (59 studies) with clinical suspicion of acute or chronic inflammation. The diagnosis of inflammation was based on cultures, autopsy findings, radiographic studies, and clinical course. The overall sensitivity and specificity to infectious foci for ILLS, considering all 80 sites studied, were 60.5%, 78.6%, and those for 67Ga were 94.7%, 47.6%. As to suppurative foci, sensitivity of ILLS and 67Ga were 95.5% and 90.9%. The duration from the onset of clinical symptoms to examination in patients with positive ILLS were significantly (p less than 0.005) shorter than in patients with negative ILLS. Also the C-reactive protein levels in patients with positive ILLS were significantly (p less than 0.05) higher than in patients with negative ILLS. Different accumulation patterns between ILLS and 67Ga were shown in 17 foci out of 21 lesions. ILLS tended to accumulate to the center of lesions strongly. On the other hand, 67Ga tended to concentrate peripherally like doughnut pattern.