Cerebral blood flow in pure dysarthria: role of frontal cortical hypoperfusion

BACKGROUND AND PURPOSE

Isolated dysarthria, termed pure dysarthria, develops rarely after stroke, and its pathophysiology remains unclear. To clarify the underlying mechanism of pure dysarthria, we investigated lesion sites and cerebral blood flow in patients with pure dysarthria.

METHODS

We examined 12 patients with pure dysarthria who underwent MRI and cerebral blood flow study. To visualize cortical blood flow, a three-dimensional display was generated from single-photon emission computed tomography (SPECT). Regional cerebral blood flow of the patients was semiquantitatively measured with SPECT and N-isopropyl-p[123I]iodoamphetamine as a tracer and compared with that of 11 control subjects.

RESULTS

On MRI, multiple lacunar infarctions were noted bilaterally in 11 patients, all of whom had lesions involving the internal capsule or corona radiata. The other patient had a unilateral internal capsule-corona radiata infarction. Three-dimensional display showed frontal cortical hypoperfusion in 8 patients. Since interhemispheric differences of blood flow were not significant in any region of the 12 patients, the mean of left and right cortical blood flow was analyzed. Compared with the control subjects, cortical perfusion was significantly reduced in the patients' frontal regions, sparing the sensorimotor, temporal, and parietal cortices and the cerebellum. Reductions of perfusion were rather pronounced in the anterior opercular, medial prefrontal and premotor, and anterior cingulate regions.

CONCLUSIONS

Pure dysarthria results mainly from multiple lacunar infarctions, which induce frontal cortical hypoperfusion, probably due to interruption of corticosubcortical networks. We conclude that frontal cortical hypoperfusion, particularly in the anterior opercular and medial frontal regions, plays an important role in the development of pure dysarthria.

Application of the polymerase chain reaction (PCR) in the epidemiology of Entamoeba histolytica and Entamoeba dispar infections

In this paper, we briefly summarize the latest information on the polymerase chain reaction (PCR) as an epidemiologic tool for Entamoeba histolytica and Entamoeba dispar infections. This method which employs DNA template directly extracted from formalin fixed stool specimens offers a good promise for an accurate and reliable epidemiology of the two species. The assay is, sensitive enough to detect as few as five cysts in the stool sample, rapid and selectively differentiates E. histolytica from E. dispar DNA from stool specimens without the need for prior cultivation.

Field study on the distribution of Entamoeba histolytica and Entamoeba dispar in the northern Philippines as detected by the polymerase chain reaction

We used the polymerase chain reaction (PCR) to study the distribution of Entamoeba histolytica and E. dispar in 1,872 individuals in 14 communities in the northern Philippines. Here we report a field study using a DNA extraction protocol from formalin-fixed stool specimens as previously reported. This assay detected 137 stools (7.318%) containing E. dispar and 18 stools (0.961%) containing E. histolytica. The most affected age group for E. histolytica/E. dispar infections were those 5-14 years of age. There was no significant difference in the sex distribution of E. histolytica, while in the case of E. dispar, a higher prevalence was observed in females (9.186%) than in males (5.731%) (P < 0.01). An apparent clustering of stool-positive cases of E. histolytica and E. dispar was also observed in the northern part of the study area. The results of this survey demonstrate that E. dispar is highly prevalent in the communities studied. Moreover, it offers promise for the PCR using DNA extracted from formalin-fixed stools as a sensitive epidemiologic tool for detecting E. histolytica and E. dispar infections.

Effects of myosin isozyme shift on curvilinearity of the left ventricular end-systolic pressure-volume relation of In situ rat hearts

Recently we have shown that the left ventricular end-systolic pressure-volume relation (ESPVR) of in situ rat hearts is an upward convex curve in contrast to the linear left ventricular ESPVR in dog and human hearts. Within the smaller left ventricular volume range, the left ventricular end-systolic pressure rose steeply with increases in left ventricular volume, but it gradually reached a plateau at the larger left ventricular volumes. In adult rat hearts, the myosin isozyme is V1, unlike V3 in dog and human hearts. To investigate whether myosin isozyme affects the curvilinearity of the left ventricular ESPVR, we evaluated the left ventricular ESPVR in hypothyroid rats in which the left ventricular myosin isozyme had been shifted to V3. In the hypothyroid rats, the left ventricular contractility was depressed and the ESPVR became closer to linear. However, after dobutamine administration the ESPVR returned to curvilinear. In nor-mal rats the curvilinearity of the left ventricular ESPVR was decreased by negative inotropic agents such as adrenergic blockers. These results indicate that the depressed left ventricular contractility in the hypothyroidism make ESPVR linear and that the enhanced left ventricular contractility from dobutamine make it curvilinear. We concluded that the curvilinearity of the rat left ventricular ESPVR is not determined by myosin isozyme per se, but by the left ventricular contractility.

Decrease in the high frequency QRS components depending on the local conduction delay

The high frequency components contained in the QRS complex (HF-QRS) are a powerful indicator for the risk of sudden cardiac death. However, it is controversial whether conduction delay increases or decreases the HF-QRS. In 21 anesthetized, open-chest dogs, the right atrium was constantly paced. A cannula was inserted into the left anterior descending artery and flecainide, lidocaine or disopyramide was infused to slow the local conduction. Sixty unipolar electrograms were recorded from the entire ventricular surface and were signal-averaged. Data were filtered (30-250 Hz) by using fast-Fourier transform. The HF-QRS was calculated by integrating the filtered QRS signal. Activation time (AT; dV/dt minimum) was delayed and the HF-QRS was reduced in the area perfused by flecainide, lidocaine or disopyramide. The percent increase in AT closely correlated the percentage decrease in the HF-QRS; the correlation coefficients were 0.75, 0.83 and 0.76 for flecainide, lidocaine and disopyramide infusion, respectively, (p<0.001). Decrease in the HF-QRS linearly correlated with the local conduction delay. This study proved that conduction delay decreases the HF-QRS, and that the HF-QRS is a potent indicator of disturbed local conduction.

Human monoclonal anti-HCMV neutralizing antibody from phage display libraries

Human cytomegalovirus (HCMV) infection in immunocompromised patients causes considerable morbidity and mortality. Although ganciclovir prophylaxis reduces the incidence of HCMV disease, severe side effects raise serious problems. Thus, the development of new strategies for prophylaxis are clearly needed, and human monoclonal antibodies offer a potential alternative. We describe the cloning, using the phage display system, of a recombinant human Fab fragment against HCMV. A phage display library with 4 x 10(6) clones was panned three times against lysates of HCMV-infected cells, and screened by ELISA. Of six antigen-binding clones, one monoclonal antibody reacted strongly to HCMV. In immunostaining analysis, this Fab was able to stain HCMV-infected cells from 24 h post-infection (pi) through to 96 h pi, but not at 6 h pi. In the presence of cytosine arabinoside, HCMV-infected cells were not stained, even at 24 h pi. These results indicate that an HCMV protein that was recognized by the Fab was synthesized in the late phase of infection. In addition, this Fab exhibited neutralizing activity: at 1 microg/ml it reduced HCMV plaque formation by 50%. The Fab was able to neutralize three HCMV strains, but it did not neutralize HSV-1 or -2 infection.

The prevalence and pattern of insomnia in Japanese industrial workers: relationship between psychosocial stress and type of insomnia

We examined the prevalence of insomnia among Japanese male industrial workers and analyzed the effect of psychosocial stress on the prevalence of three types of insomnia: 'difficulty in falling asleep', 'frequent sleep interruption' and 'early morning arousal'. The study population consisted of male day workers (n = 319) in a manufacturing heavy industry company located in Nagasaki City, Japan. The subjects answered a questionnaire consisting of six sleep-related items and 24 questions related to occupational and private life conditions. A total of 271 men (average age 40.9 years) completed the questionnaire; a response rate of 85%. Insomnia within the month preceding the survey was present in 27.7% of the workers (75/271). Multiple logistic regression analysis demonstrated that different psychosocial stressors were associated with different types of insomnia. Visual display terminal (VDT) work overload was significantly associated with all types of insomnia, while 'over-involvement in the job' was associated with difficulty in falling asleep and early morning arousal. Our results demonstrated that the prevalence of insomnia in Japanese workers is similar to that reported among European and American general adult population. Our results also indicate that the use of VDT in the workfield is associated with insomnia.

Identification of the 150-kDa surface antigen of Entamoeba histolytica as a galactose- and N-acetyl-D-galactosamine-inhibitable lectin

A monoclonal antibody that reacts with a 150-kDa protein of Entamoeba histolytica on Western immunoblotting under nonreducing conditions inhibits the adherence and cytotoxicity of the ameba to mammalian cells in vitro. Affinity purification of solubilized trophozoites using the monoclonal antibody and electrophoresis yielded three glycoproteins with molecular masses of 150, 170, and 260 kDa, suggesting the existence of either a common epitope or the close association of these proteins. The 260-kDa fraction was identified as the well-known galactose (Gal)- and N-acetyl-D-galactosamine (GalNAc)-inhibitable lectin. The 150- and 170-kDa fractions seemed to exist as part of a 380-kDa native protein with an isoelectric point of pH 6.9. The N-terminal amino acid sequence of the 150-kDa protein was unique, indicating that the protein was not a degraded product of the 260-kDa lectin. By gel filtration, the 260-kDa lectin and the 150/170-kDa protein could be separated. When Chinese hamster ovary cells were pretreated with the fraction consisting of the 150/170-kDa protein the adherence of trophozoites to Chinese hamster ovary cells was competitively inhibited to a level equivalent to that observed for the 260-kDa lectin. The inhibitory effect was lost in the presence of Gal and GalNAc but was not influenced by the presence of glucose. These results demonstrate that the 150/170-kDa protein is a Gal/GalNAc-inhibitable lectin. The existence of a sugar-binding domain in the protein was confirmed by Gal-affinity chromatography.

Discordant S-T alternans contributes to formation of reentry: a possible mechanism of reperfusion arrhythmia

Although a relationship between S-T alternans and life-threatening arrhythmia has been recognized, the mechanism is poorly understood. We examine the role of S-T alternans in the occurrence of ventricular fibrillation (VF) after reperfusion. The left anterior descending coronary artery was occluded for 20 min and then abruptly reperfused in 12 intravenously anesthetized open-chest dogs. Sixty unipolar epicardial electrograms were recorded during the control state, at the end of occlusion, and after reperfusion. The largest magnitude of S-T alternans among 60 leads was defined as the maximum S-T alternans. Isochronal maps of activation time in paced beat and spontaneous ventricular premature contractions (VPC) were analyzed. After reperfusion, VF ensued in six dogs. The maximum S-T alternans augmented progressively with time after reperfusion until VF occurred. In three dogs with VF, when activation of VPC resulted in conduction block and formed reentry, VF ensued. The conduction block was located between sites of discordant S-T alternans (S-T alternans at adjacent leads was out of phase). These data indicate that discordant S-T alternans relates to VF by facilitating the formation of a reentrant circuit.

Bronchoprotective effect of an intrabronchial administration of cilostazol powder and a nebulized PDE1 and PDE4 inhibitor KF19514 in guinea pigs

BACKGROUND

Both oral and intravenous inhibitors of cyclic nucleotide phosphodiesterase (PDE) 3 and PDE4 have been shown to have bronchodilator and/or pulmonary antiallergic effects but their adverse effects limit the clinical use. The purpose of the present study was to assess the bronchoprotective effect of intrabronchial administration of a selective PDE3 inhibitor, 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy]-3,4-dihydro-2(1H)-quin olinone (cilostazol), in dry power form which is proposed to be desirable rather than propellant-driven metered-dose inhalers.

METHODS

Effect of an intrabronchial administration of cilostazol powder on aerosolized histamine- and antigen-induced leukotriene-mediated bronchoconstriction were examined in anesthetized and artificially ventilated guinea pigs, in comparison with the effects of ultrasonically nebulized 5-phenyl-3-(3-pyridyl)methyl-3H-imidazo[4,5-c] [1,8] naphthyridin-4(5H)-one (KF19514), a selective PDE1/4 inhibitor.

RESULTS

Cilostazol powder and KF19514 solution inhibited histamine- and antigen-induced bronchoconstriction in a dose-dependent manner. When assessing the resulting ED50 values, the activity of cilostazol powder against antigen-induced broncho-constriction was weaker than its antagonism of histamine-induced bronchoconstriction (60.4 vs. 7.0 microg), while those of KF19514 were the opposite (0.40 vs. 2.81 microg/ml).

CONCLUSION

These results suggest that intrabronchially administered cilostazol powder has a bronchodilator effect, and ensure that PDE4 inhibitors have an antiallergic activity in addition to their bronchodilator effect.

Basophilic differentiation of the human leukemia cell line KU812 upon treatment with interleukin-4

The human leukemia cell line KU812 had been described as an immature prebasophilic cell line and exhibits a potential to differentiate into mature basophils. We studied the effect of interleukin-4 (IL-4) on the basophilic differentiation of KU812 cells. When KU812 cells were cultured with 1 ng/ml IL-4, cellular histamine content increased more than 10-fold. IL-4 also enhanced the expression of Fc epsilon RI alpha, a high affinity IgE receptor, on the cell surface. KU812 cells treated with IL-4 expressed higher levels of Fc epsilon RI alpha, Fc epsilon RI beta and Fc epsilon RI gamma mRNA than non treated KU812 cells. After 21 days in culture with IL-4, KU812 cells became morphologically mature basophilic cells as demonstrated by staining positive for cytoplasmic granules and heparin proteoglycan by Wright dye and toluidin blue dye respectively. In addition, IgE-mediated histamine release was observed, suggesting that the Fc epsilon RI induced by IL-4 was functional and was able to transduce a signal for degranulation. These results suggest that IL-4 promotes differentiation of KU812 cells into mature basophilic cells both morphologically and functionally.

In vivo observations of the intramural arterioles and venules in beating canine hearts

1. To evaluate the effects of cardiac contraction on intramyocardial (midwall) microvessels, we measured the phasic diameter change of left ventricular intramural arterioles and venules using a novel needle-probe videomicroscope with a CCD camera and compared it with the diameter change in subepicardial and subendocardial vessels. 2. The phasic diameter of the intramural arterioles decreased from 130 +/- 79 ìm in end-diastole to 118 +/- 72 micron (mean +/- S.D.) in end-systole by cardiac contraction (10 +/- 6 %, P < 0.001, n = 21). 3. The phasic diameter in the intramural venules was almost unchanged from end-diastole to end-systole (85 +/- 44 vs. 86 +/- 42 micron, respectively, 2 +/- 6 %, n. s., n = 14). 4. Compared with intramural vessels, the diameters of subendocardial arterioles and venules decreased by a similar extent (arterioles: 10 +/- 8 %, P < 0. 001; venules: 12 +/- 10 %, P < 0.001) from end-diastole to end-systole, respectively, whereas the diameter of the subepicardial arterioles changed little during the cardiac cycle, and subepicardial venule diameter increased by 9 +/- 8 % (P < 0.01) from end-diastole to end-systole. These findings are consistent with our previous report. 5. We suggest that the almost uniform distribution of the cardiac contractility effect and arteriolar transmural pressure between the subendocardium and the midmyocardium, which together constitute the systolic vascular compressive force, accounts for the similarity in the arteriolar diameter changes in both myocardial layers. The smaller intravascular pressure drop from deep to superficial myocardium relative to the larger intramyocardial pressure drop explains the difference in the phasic venular diameter changes across the myocardium.

Asymmetric changes in somatosensory evoked potentials correlate with limb apraxia in corticobasal degeneration

To clarify the underlying mechanism of limb apraxia in corticobasal degeneration (CBD), we investigated somatosensory evoked potentials in 5 patients with CBD, as compared with 12 age-matched control subjects. All patients presented with asymmetric limb apraxia, particularly of limb-kinetic type. N20 latencies were significantly prolonged following median nerve stimulation on the more apraxic side, but not on the less apraxic side. These results suggest that limb apraxia in CBD may, at least in part, be due to a disorder of somatosensory information processing involving the parietal cortex.

Electrophysiological comparison between corticobasal degeneration and progressive supranuclear palsy

Multimodal evoked potentials were recorded in four patients with corticobasal degeneration (CBD), four patients with progressive supranuclear palsy (PSP) and 15 normal control subjects. CBD and PSP patients showed significant prolongation of the N200 and P300 latencies of auditory event-related potentials compared with controls. Patients with CBD showed significant prolongation of interpeak latencies between N13 and N20 of short-latency somatosensory evoked potentials compared with the controls and patients with PSP. The present results show that the two diseases have different electrophysiologic features.

[Memory function in aging and Parkinson's disease--an event-related potential study]

The N400 of event-related potentials (ERPs) was recorded in 17 healthy young subjects (mean age 24.4 years), 14 healthy old subjects (healthy control subjects, mean age 62.7 years), and 21 patients with nondemented Parkinson's disease (PD, mean age, 63.8 years) as they listened to words or nonwords. Some words were repeated immediately after the initial presentation (2 sec), while others were repeated after 5 intervening words (12 sec) or after 2 to 4 minutes. The subjects were required to respond to occasional nonwords. Rey's auditory verbal learning test(AVLT) was also performed. The mean N400 amplitude was smaller in patients with PD than in either healthy group, but there was no difference between the two healthy groups. In the young subjects, N400 was attenuated for repeated words, and the attenuation was more pronounced for immediate than for delayed repetitions. N400 attenuation in the old subjects was more markedly reduced as the interval between the 1st and 2nd presentation increased than in the young subjects. In PD patients, attenuation was noted only for immediate repetition. Free recall by the old subjects was impaired relative to the young subjects throughout the AVLT trials, and was even more impaired in patients with PD. In addition, the number of free recalls increased less with the number of trials in patients with PD than in the old subjects. These results may indicate that episodic memory declines with advancing age, and declines even more in patients with PD. In addition, the ability to transform information form short-term memory to long-term memory appear to be impaired in patients with PD.

A case of subwakefulness syndrome

We report a patient, a 30-year-old male Japanese-Brazilian migrant construction worker, suffering from excessive daytime sleepiness for at least 6 months. Electroencephalogram recordings during his waking states showed that 10-Hz and 60-microV alpha activity was present prominently in the occipital regions. From the multiple sleep latency test, it was found that stages 1-2 NREM sleep episodes appeared repetitively without any REM episodes, and that the mean sleep latency was 10.2 min. These findings support the diagnosis that this patient suffers from subwakefulness syndrome.

Entamoeba dispar: cultivation with sterilized Crithidia fasciculata

Four isolates of Entamoeba dispar identified by their hexokinase and phosphoglucomutase isoenzyme profile and by their failure to react with Entamoeba histolytica-specific monoclonal antibody (4G6) could be grown in either Diamond's BI-S-33 medium, newly developed BCSI-S (Biosate cysteine starch iron-serum) medium, or casein-free YI-S medium in the presence of Crithidia fasciculata (ReF-1:PRR) sterilized by heating 56 degrees C for 30 min and subsequent incubation with 1% hydrogen peroxide for 24 hours at 4 degrees C. After the cultures were maintained for over 50 passages, the amebae were identified as E. dispar by isoenzyme analysis, polymerase chain reaction with E. histolytica- and E. dispar-specific primers, i.e. p11 plus p12 and p13 plus p14, respectively, and by negative reactivity with monoclonal antibody 4G6. The flagellates added to the culture were judged to be metabolically inactive based on the results of nuclear magnetic resonance spectroscopy, electron microscopy, and polarographic analysis. All of these findings suggest that E. dispar can grow in vitro with metabolically inactive C. fasciculata as a culture associate.

Mechanoenergetics of rat left ventricles in in situ and excised blood-perfused hearts and in unloaded rat left ventricular slices

We investigated rat left ventricular (LV) mechanoenergetics in three different preparations. We obtained an upward convex curvilinear end-systolic pressure-volume relation (ESPVR) regardless of left ventricular (LV) contractility in in situ and excised cross-circulated rat hearts. We also obtained a linear myocardial O2 consumption per beat (VO2)-end-systolic pressure-volume area (PVA; a measure of ventricular total mechanical energy) relation regardless of the curvilinear LV ESPVR in the excised cross-circulated heart. The slope and the VO2 intercept of the VO2-PVA relation was similar to those in other species. The basal metabolism obtained by KCl arrest was higher than those in other species. In the whole heart preparation, the VO2 intercept may include O2 consumption for residual crossbridge cycling as well as O2 consumption for excitation-contraction (E-C) coupling and basal metabolism. Therefore, we established a new system for measuring myocardial O2 consumption of mechanically unloaded (zero PVA) rat LV slices. The increment in O2 consumption by stimulation of the slices represents O2 consumption for E-C coupling (but not for crossbridge cycling). Most O2 consumption for E-C coupling seems consist of O2 consumption for the sarcoplasmic reticulum Ca2+ pump.

Role of leukotriene B4 in bronchial hyperresponsiveness induced by interleukin-8

Repeated intranasal administration of interleukin 8 (IL-8) induces bronchial hyperresponsiveness (BHR) accompanied by lower airway neutrophil accumulation (ANA) in guinea-pigs. Leukotriene B4 (LTB4) is a chemotactic factor for neutrophils. To elucidate whether LTB4 and neutrophil elastase are involved in the IL-8-induced BHR and ANA, the effects of a LTB4 antagonist (ONO-4057) and a neutrophil elastase inhibitor (ONO-5046) on the responses were examined. IL-8 (5 microg x kg[-1]) was administered intranasally to guinea-pigs twice weekly for 3 weeks. One day after the last administration, animals were anaesthetized and artificially ventilated through tracheal cannulae, and lateral pressure at the tracheal cannula (Pao) was measured as an overall index of airway responses to inhaled histamine. ONO-4057 (2 or 20 mg x kg[-1]) or ONO-5046 (30 or 300 mg x kg[-1]) was administered intraperitoneally 24 and 1 h before anaesthesia. ONO-4057, but not ONO-5046, significantly inhibited the IL8-induced BHR and ANA, assessed by bronchoalveolar lavage, in a dose-dependent manner. These findings suggest that interleukin 8 causes bronchial hyperresponsiveness and airway neutrophil accumulation in guinea-pigs in vivo. In part this appears to be due to release of leukotriene B4, whereas it may not be mediated by neutrophil elastase.