[A family with dentato-rubro-pallido-luysian atrophy (DRPLA): an intergenerational contraction of the CAG repeat]

We describe the relation of the CAG repeat length to the genetic anticipation in a Japanese family with dentato-rubro-pallido-luysian atrophy (DRPLA). The proband, a 21-year-old woman, developed epilepsy at age 19. Her mother has displayed cerebellar ataxia, choreoathetosis, and dementia since age 40, and the grandmother has shown cerebellar ataxia since age 52. So a genetic anticipation was observed. The CAG repeat sizes of peripheral blood lymphocytes from the proband, mother, and grandmother were found to be 61, 59, and 60, respectively. Thus, the mother showed earlier onset but a smaller CAG repeat length as compared to the grandmother. This case is thought to be rare and valuable in respect that the intergenerational contraction of the CAG repeat was shown in spite of the genetic anticipation was observed.

Relationship of (CAG)nC configuration to repeat instability of the Machado-Joseph disease gene

The mutation responsible for Machado-Joseph disease (MJD) has been identified as an expansion of a CAG trinucleotide repeat in a novel gene on chromosome 14q32.1. The CAG repeat tract is followed by C or G, and alleles are thereby divided into two types on the basis of molecular configuration, (CAG)nC and (CAG)nG. We have studied the relationship between the repeat length and the configuration in 38 patients from 28 Japanese families with MJD, and 31 unrelated normal Japanese subjects. The CAG repeat length in 100 normal alleles ranged from 13 to 37 repeats, while 38 MJD patients had one expanded allele with 64 to 84 repeats. Surprisingly, the expanded alleles had exclusively the (CAG)nC configuration, while both (CAG)nC and (CAG)nG were seen in normal alleles from MJD and control subjects. Furthermore, in normal alleles, the CAG repeat tract was significantly longer in (CAG)nC than in (CAG)nG. These findings suggest that the (CAG)nC configuration is related to repeat instability of the MJD gene.

Autosomal dominant cerebellar ataxias in the Kinki area of Japan

The autosomal dominant cerebellar ataxias are a heterogeneous group of neurodegenerative disorders characterized by slowly progressive cerebellar ataxia. Recently, among the ataxias, spinocerebellar ataxia type 1 (SCA1), Machado-Joseph disease (MJD) and dentatorubral-pallidoluysian atrophy have been found to be caused by expansion of a CAG trinucleotide repeat in the coding region of the disease genes. We have analyzed the CAG repeats of 67 patients from 47 families with dominantly inherited ataxia who lived in the Kinki area of Japan. The following results were obtained. First, 31 patients from 22 families were found to be positive for the MJD repeat expansion, indicating that MJD is the most common dominantly inherited ataxia in the Kinki area of Japan. Second, no SCA1 repeat expansion was found among the families studied. This presents a striking contrast to the fact that there are many families with SCA1 in Hokkaido and the Tohoku area of Japan. These findings suggest geographic variation in autosomal dominant cerebellar ataxias in Japan.

The importance of the hyperpolarizing mechanism increases as the vessel size decreases in endothelium-dependent relaxations in rat mesenteric circulation

Endothelium-dependent relaxations are achieved by a combination of endothelium-derived prostacyclin (PGI2), nitric oxide (NO), and endothelium-derived hyperpolarizing factor (EDHF). However, it remains to be fully clarified whether the relative contribution of these three mechanisms to endothelium-dependent relaxations varies as a function of the vessel size. This study was designed to clarify this point. Acetylcholine (ACh)-induced endothelium-dependent relaxations were examined in isolated blood vessels taken from the aorta and the proximal and distal mesenteric arteries of the rat. The contributions of PGI2, NO, and EDHF were evaluated by the inhibitory effects of indomethacin, N omega-nitro-L-arginine methyl ester (L-NAME) in the presence of indomethacin, and KCl in the presence of indomethacin and L-NAME, respectively. The membrane potentials were recorded with microelectrodes. The expression of endothelial No synthase (eNOS) was examined by both immunostaining and immunoblotting. The contribution of PGI2 was negligible in three different-sized blood vessels. The contribution of NO was most prominent in the aorta, whereas that of EDHF was most prominent in the distal mesenteric arteries. The resting membrane potential was significantly deeper and the ACh-induced hyperpolarization was greater in the distal mesenteric arteries than those in the aorta. The expression of eNOS was the highest in the aorta and the lowest in the distal mesenteric arteries. These results indicate that the importance of EDHF increases as the vessel size decreases in endothelium-dependent relaxations in the rat mesenteric circulation.

[Sympathetic skin responses in the face by magnetic stimulation of the neck]

We studied the sympathetic skin responses (SSRs) in the face with magnetic stimulation of the neck, in 10 normal healthy subjects. The SSRs were recorded with surface electrodes placed on the forehead, the lower eyelid, the apex nasi, two points of cheek (one is near the ear, and another is near the mouth), the upper lip, and the lower jaw. Reproducible SSRs were obtained easily at the forehead and the upper lip compared to the other parts of the face. The SSRs on the forehead and upper lip were constantly evoked after drinking of hot water. Mean latencies are 0.98 +/- 0.22 sec. (mean +/- 1SD) at the forehead, and 0.89 +/- 0.12 sec. (mean +/- 1SD) at the upper lip. In the cervical sympathetic pathway, one part of postganglionic fibers runs along the internal carotid artery to innervate the eyelids and forehead, whereas another part runs along the external carotid artery to innervate other parts of the face. It suggests that the forehead and the upper lip are representative parts of those different innervations SSRs in the forehead and the upper lip could be useful for evaluating the sympathetic function of the face in various diseases.

The role of fibroblast growth factor-2 in the vascular effects of interleukin-1 beta in porcine coronary arteries in vivo

OBJECTIVE

We recently demonstrated that chronic treatment with interleukin-1 beta (IL-1 beta), a major inflammatory cytokine found in atherosclerotic lesions, induces coronary arteriosclerotic changes and vasospastic responses to serotonin and histamine in pigs in vivo and that those responses are partially mediated by platelet-derived growth factor (PDGF). This study was designed to examine, first, whether the effects of IL-1 beta are also partially mediated by fibroblast growth factor-2 (FGF-2), which is another important growth factor in atherosclerotic lesions, and, secondly, whether chronic treatment with FGF-2 per se also induces histological and functional changes in porcine coronary arteries in vivo.

METHODS

Porcine coronary arteries were aseptically wrapped with cotton mesh absorbing IL-1 beta with or without neutralizing antibody to FGF-2. In a separate series of experiments porcine coronary arteries were chronically treated with FGF-2 itself in the same manner. Coronary vascular responses in vivo and histological changes were examined 2 weeks after the operation.

RESULTS

Coronary vasospastic responses to serotonin and histamine and neointimal formation were induced at the site of the coronary artery where IL-1 beta was chronically and locally applied. These responses were significantly suppressed by co-treatment with a neutralizing antibody to FGF-2 but not by that with non-immune IgG. Immunostaining revealed the presence of FGF-2 in the endothelial cells, the thickened intima and the media at the IL-1 beta-treated site. Furthermore, chronic treatment with FGF-2 also induced coronary vasospastic responses to serotonin and histamine and neointimal formation.

CONCLUSIONS

These results suggest that the vascular effects of IL-1 beta may also be mediated by FGF-2 in our swine model and that chronic treatment with FGF-2 also causes coronary arteriosclerotic changes and vasospastic responses in vivo.

[The relationship between muscle pathology and DM kinase abnormalities in patients with dystrophia myotonica]

We studied the relationship between muscle pathology and the number of trinucleotide (CTG) repeats observed in lymphocytes and biopsied muscle tissues from patients with dystrophia myotonica (DM). The diameter of type 1 muscle fibers was smaller than that of type 2 fibers in all patients. The diameter and proportion of each muscle fiber type were related to the patient's age, but not to the number of trinucleotide (CTG) repeats of DM kinase in biopsied muscles. On the other hand, the proportion of type 1 fibers with central nuclei was closely related to the number of trinucleotide (CTG) repeats in muscles. These findings suggest that DM kinase abnormalities influence the muscle nuclei, and increase the number of central nuclei.

Coronary artery spasm does not depend on the intracellular calcium store but is substantially mediated by the protein kinase C-mediated pathway in a swine model with interleukin-1 beta in vivo

BACKGROUND

The intracellular mechanism for coronary artery spasm is still unknown. Since the protein kinase C (PKC)-mediated pathway and Ca2+ release from sarcoplasmic reticulum (SR) are important intracellular mechanisms of vascular smooth muscle contraction, we examined the possible role of these two mechanisms in the pathogenesis of coronary spasm in our swine model in vivo.

METHODS AND RESULTS

In 25 pigs, interleukin-1 beta (IL-1 beta) was applied chronically to the coronary arteries from the adventitia to induce an inflammatory/proliferative lesion. Two weeks after the operation, either intracoronary serotonin or histamine repeatedly induced coronary spasm at the IL-1 beta-treated site. At those spastic sites, phorbol-12, 13-dibutyrate, a PKC-activating phorbol ester, also induced coronary spasm, which was blocked by pretreatment with the PKC inhibitors staurosporine and sphingosine. Serotonin- and histamine-induced coronary spasm was also significantly inhibited by pretreatment with staurosporine, sphingosine, or nifedipine (an L-type Ca2+ channel antagonist) but not by ryanodine (an inhibitor of Ca(2+)-induced Ca2+ release from SR) or thapsigargin (an inhibitor of Ca(2+)-ATPase of SR). Bay K 8644 (an L-type Ca2+ channel agonist) also induced coronary spasm at the IL-1 beta-treated site, which was significantly inhibited by pretreatment with staurosporine, sphingosine, and nifedipine. In contrast, coronary vasoconstriction induced by prostaglandin F2 alpha was not affected by pretreatment with staurosporine or sphingosine but was significantly inhibited by pretreatment with ryanodine, thapsigargin, or nifedipine.

CONCLUSIONS

These results suggest that (1) PKC activation largely accounts for the serotonin- and histamine-induced coronary spasm; (2) at the spastic site, the calcium influx through L-type Ca2+ channels may be augmented via the PKC-mediated pathway; and (3) the Ca2+ release from the SR into the cytosol may not play a primary role in coronary spasm.

An intergenerational contraction of the CTG repeat in Japanese myotonic dystrophy

We present the first report of a Japanese family with myotonic dystrophy (DM) that showed an intergenerational contraction of the CTG repeat. The size of the expanded CTG repeats was 3.2 kb for the father and 2.2 kb for the daughter, indicating that the expansion decreased during transmission from the father to the daughter. Despite the CTG repeat contraction, the daughter showed earlier age of onset than the father. However, she appeared to be less severely affected than the father. We discuss the correlation between the CTG repeat contraction and the clinical phenotype. The presence of the CTG repeat contraction in Japanese DM is important for genetic counseling of Japanese DM families.

The relationship between trinucleotide repeat length and phenotypic variation in Machado-Joseph disease

Trinucleotide repeat expansion in the Machado-Joseph disease (MJD) gene has been found in 26 patients from 20 unrelated Japanese families. Expanded alleles had 68 to 84 repeats, whereas normal alleles had 14 to 37 repeats. The age of onset was inversely correlated with the repeat length. To evaluate in detail the relationship between the repeat length and clinical features, we subdivided the 26 patients into three groups on the basis of the repeat length (group 1, 78 repeats or more; group 2, 74 to 77 repeats; group 3, 73 repeats or less). Group 1 and group 2 had common features of spasticity, hyperreflexia, Babinski sign, bulging eyes, facial myokymia and extrapyramidal signs as well as cerebellar ataxia and ophthalmoplegia. It should be noted that group 1 showed more prominent pyramidal and extrapyramidal signs than group 2. In contrast, group 3 showed hypotonia, hyporeflexia and sensory disturbance in addition to cerebellar ataxia and ophthalmoplegia. These findings suggest that the repeat length plays an important role in phenotypic variation. DNA analysis for the MJD mutation was clearly useful for making an accurate diagnosis in patients without bulging eyes, facial myokymia, dystonia or marked spasticity.

Chronic treatment with interleukin-1 beta induces coronary intimal lesions and vasospastic responses in pigs in vivo. The role of platelet-derived growth factor

Studies in vitro have suggested that inflammatory cytokines may play an important role in the pathogenesis of atherosclerosis. However, little is known about their effects in vivo. Thus, the present study was designed to determine in vivo what histological and functional changes may be induced by chronic treatment with IL-1 beta, one of the major inflammatory cytokines, and also to clarify what mechanisms are involved in those changes. Under aseptic conditions, proximal segments of the left porcine coronary arteries were gently wrapped with cotton mesh absorbing Sepharose beads either with or without recombinant human IL-1 beta. From 1 to 4 wk after the operation, coronary vasospastic responses to intracoronary serotonin or histamine were noted at the IL-1 beta-treated site but not at the control site. Histologically, intimal thickening was greater at the IL-1 beta-treated site than at the control site. Those functional and histological changes induced by the chronic treatment with IL-1 beta were significantly inhibited by the simultaneous treatment with a neutralizing antibody to either IL-1 beta or PDGF. These results indicate that chronic treatment with Il-1 beta induces coronary intimal lesions and vasospastic responses in porcine coronary arteries in vivo and also suggest that these changes are substantially mediated by PDGF.

[Serum levels of soluble adhesion molecules in patients with inflammatory myopathies]

Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured by ELISA in patients with 18 inflammatory myopathies as well as 23 healthy controls. Both serum sICAM-1 and sVCAM-1 levels were elevated in patients with active polymyositis. Serum sVCAM-1 levels were elevated in the active stage of dermatomyositis, while sICAM-1 levels were elevated only in patients with dermatomyositis complicated with interstitial pneumonia. In paired serum samples before and after prednisolone therapy, elevated serum sICAM-1 and sVCAM-1 levels decreased in patients responding well to steroid therapy without complications. These findings suggested that soluble adhesion molecules reflect as the clinical activity of inflammatory myopathies.

[Motor reorganization in the motor cortex]

Plasticity within the human central motor system has been studied with transcranical magnetic stimulation in patients with peripheral and central nervous diseases. In 4 patients with a complete upper limb palsy due to traumatic cervical root avulsion, surgical anastomosis of intercostal to musculocutaneous nerves was performed to restore function in the biceps brachii muscle. The motor unit discharges became independent from respirations gradually over 1 to 2 years. Motor cortex mapping of the reinnervated biceps muscle showed a gradual change over 4 to 33 months from the area of the intercostal muscles to that of the arm area, which was more lateral on the motor cortex. These findings suggest that reorganization of the motor cortex to arm flexor muscles occurs following peripheral nerve anastomosis. In 8 patients with chronic cerebral infarction with hemiplegia. Four of 8 patients did not show MEPs in paralytic hand muscles by contralateral cortex stimulation, but showed small MEPs by ipsilateral cortex stimulation. These cases had the huge cortical infarction unilaterally in CT. Another four of 8 patients showed small MEPs in paralytic hand muscles by contralateral cortex stimulation, but no MEPs by ipsilateral cortex stimulation. These cases had the subcortical infarction unilaterally in CT. These findings suggest that reorganization of motor cortex following unilateral cerebral infarction.

Chronic inhibition of endothelium-derived nitric oxide synthesis causes coronary microvascular structural changes and hyperreactivity to serotonin in pigs

BACKGROUND

Endothelium-derived nitric oxide (NO) is believed to regulate myocardial perfusion and structural changes in the vascular wall. Our objective was to determine whether chronic inhibition of NO synthesis causes structural and functional changes in coronary arteries.

METHODS AND RESULTS

Coronary vasomotor response was studied in pigs before and after chronic oral administration of the NO synthesis antagonist N omega-nitro-L-arginine methyl ester (L-NAME) 30 mg.kg-1.d-1 for 2 weeks. Chronic L-NAME treatment increased (P < .01) arterial pressure but did not alter baseline coronary blood flow (CBF), epicardial coronary diameter, or heart rate. Chronic L-NAME treatment augmented (P < .01) the decrease in CBF in response to intracoronary serotonin (30 micrograms/kg) from 5 +/- 14% to 40 +/- 5% but did not alter the CBF response to prostaglandin F2 alpha. The serotonin-induced decrease in CBF after acute L-NAME administration was still less before (1.3 +/- 0.4%) than after chronic L-NAME treatment (51 +/- 6%). Chronic L-NAME treatment attenuated the increase in CBF with bradykinin (100 ng/kg) but did not alter the CBF response to nitroglycerin (10 micrograms/kg). Compared with intact pigs without L-NAME treatment, L-NAME-treated pigs had significant thickening of the media in the microvessels (diameter, < 300 microns) but not in the large epicardial vessels. Chronic intracoronary infusion of L-NAME at 3 mg.kg-1.d-1 for 2 weeks, which did not produce arterial hypertension, caused similar microvascular medial thickening.

CONCLUSIONS

These results indicate that chronic administration of L-NAME caused coronary microvascular structural changes and hyperreactivity to serotonin in pigs in vivo, suggesting an important role of defective NO synthesis in coronary microvascular disorders.

Early detection of cutaneous microcirculatory change during hemorrhage using a laser Doppler flowmetry

The purpose of the present study was to evaluate the usefulness of cutaneous microcirculatory monitoring during hemorrhage. We observed changes in cutaneous blood volume, velocity and flow of five adult rabbits during hemorrhage by using a laser Doppler flowmetry. Mean arterial blood pressure, heart rate and blood gas values were measured. Cutaneous blood volume, velocity and flow decreased significantly after drawing 10 mL/kg of blood, while heart rate, mean arterial blood pressure and blood gas did not change. The decrease of cutaneous blood velocity preceded that of blood volume and was associated more deeply with the reduction of blood flow. In conclusion, cutaneous microcirculatory monitoring using laser Doppler flowmetry is a sensitive technique for detecting early changes of circulatory failure caused by hemorrhage.

Tyrosine kinase inhibitor suppresses coronary arteriosclerotic changes and vasospastic responses induced by chronic treatment with interleukin-1 beta in pigs in vivo

We recently demonstrated that chronic treatment with IL-1 beta induces coronary arteriosclerotic changes and vasospastic responses to autacoids in pigs in vivo and that those responses are importantly mediated by PDGF. The receptors for PDGF and other major growth factors are known to have tyrosine kinase activity. We therefore investigated the effects of a selective tyrosine kinase inhibitor, ST 638, on those responses induced by IL-1 beta in our swine model. Intimal thickening and coronary vasospastic responses to serotonin and histamine were induced at the site of the coronary artery where IL-1 beta was chronically and locally applied. These responses were significantly suppressed in a dose-dependent manner by cotreatment with ST 638. In addition, ST 494, which is an inactive form of ST 638, did not inhibit those responses. The treatment with ST 638 alone did not affect the coronary vasoconstricting responses to the autacoids. Immunoblotting using an antibody to phosphotyrosines confirmed the inhibitory effects of ST 638 on the tyrosine phosphorylations induced by IL-1 beta. These results thus suggest that tyrosine kinase activation may play an important role in mediating the effects of IL-1 beta, while also suggesting that ST 638 has an inhibitory effect on the arteriosclerotic changes and vasospastic responses to autacoids in our swine model in vivo.

Production of minor lymphocyte stimulatory-1a antigens from T cell subsets

T cell subsets that produce minor lymphocyte stimulatory (Mls) antigens were analyzed using mixed lymphocyte reaction (MLR) in vitro or clonal elimination assay in vivo. When lymph node T cells from B10.BR(Mls-1b) mice were stimulated with various T cell subsets from AKR (Mls-1a) mice in the presence of B10.BR antigen presenting cells (APC), proportions of Mls-1a reactive T cell blasts (V beta 6+, V beta 8.1+) increased. The stimulatory potency of CD8+ T cells was higher than that of CD4+ T cells. Furthermore, among either CD8+ or CD4+ T cell subset, CD44+ T cells appeared to produce larger amounts of Mls-1a antigens than CD44- T cells. More marked difference was demonstrated, when stimulator AKR T cells were being activated by immobilized anti-T cell antigen receptor (TCR) antibody during MLR. Thus, AKR T cells appeared to produce large amounts of Mls-1a antigens on appropriate stimulations. These findings were confirmed by the semiquantitative analysis of mRNA levels of MTV-7 in the AKR T cell subsets. When CD8+CD44+ T cells from (AKR x B10.BR)F1 mice were injected intravenously into [B10.BR-->B10.BR] syngeneic bone marrow (BM) chimeras 1 week after BM reconstitution and proportions of V beta 6+ T cells were quantitated 7 weeks later, significant clonal elimination of V beta 6+ T cells was induced among both thymocyte population and lymph node T cell population in a dose-dependent manner of the inoculated F1 T cells. Inoculation of CD8+CD44-F1 T cells eliminated V beta 6+ T cells less efficiently from lymph node T cells and inoculation of CD4+F1 T cells induced no significant clonal elimination of the V beta 6+ T cells. The present findings demonstrate clearly that CD8+CD44+ T cells represent the cells producing large amounts of Mls-1a antigens and inducing clonal elimination of V beta 6+ T cells in vivo.

Glibenclamide, a selective inhibitor of ATP-sensitive K+ channels, attenuates metabolic coronary vasodilatation induced by pacing tachycardia in dogs

BACKGROUND

We previously reported that glibenclamide (a selective inhibitor of ATP-sensitive K+ channels [K+ATP channels]) inhibited metabolic coronary vasodilatation induced by beta 1-adrenoceptor stimulation. However, the role of K+ATP channels in metabolic coronary vasodilatation induced by tachycardia is still unknown. This study aimed to determine whether glibenclamide attenuates metabolic coronary vasodilatation induced by pacing-induced tachycardia.

METHODS AND RESULTS

In anesthetized dogs, increasing heart rate from 103 +/- 1 to 160 beats per minute with atrial pacing increased coronary blood flow without altering arterial pressure and left ventricular pressure. Intracoronary infusion of glibenclamide at 1.5 and 5.0 micrograms.kg-1.min-1 did not alter basal coronary blood flow but significantly attenuated (P < .01) the tachycardia-induced coronary vasodilatation without altering the tachycardia-induced increase in myocardial oxygen consumption (MVO2). In conscious dogs, intracoronary glibenclamide at 5.0 micrograms.kg-1.min-1 attenuated (P < .05) coronary vasodilatation induced by ventricular pacing from 85 +/- 6 to 150 beats per minute. Glibenclamide markedly attenuated coronary vasodilation evoked with the K+ATP channel opener pinacidil.

CONCLUSIONS

These data indicate that blockade of coronary vascular K+ATP channels with glibenclamide inhibited metabolic coronary vasodilatation induced by pacing tachycardia in dogs, suggesting that K+ATP channels are involved in the mechanism mediating metabolic coronary vasodilatation associated with pacing tachycardia.

[A study of heel-knee tapping test in cerebellar ataxia by a motion measurement system]

It is often difficult to estimate slight alterations in the severity of ataxia by bed-side neurological examinations. We analyzed the heel-knee tapping test, which has often been used as a standard bed-side examination to check incoordination in lower limbs, using a new motion measurement system "video/computer motion measurement system". We studied 9 normal controls and 21 patients with spinocerebellar degenerations (SCD). In patients with SCD, the up-and-down motion range of the heel was variable and the heel moved in the anterior-and-posterior direction, because of knee sways during the test. Following oral administration of TRH analogue, TA-0910, above-mentioned findings were clearly improved. Analysis of spatial and time elements of the knee joint demonstrated quantitative improvement. Therefore, an effect of TA-0910 on incoordination of the lower limbs could be proved objectively by a computer motion measurement system.

Central motor reorganization after anastomosis of the musculocutaneous and intercostal nerves following cervical root avulsion

In 4 patients with a complete upper limb palsy due to traumatic cervical root avulsion, surgical anastomosis of intercostal to musculocutaneous nerves was performed to restore function in the biceps brachii muscle. Four to 6 months after the operation, motor unit discharges were recorded from the biceps muscle on the operated side during deep breathing and by cortical magnetic stimulation. The motor unit discharges became independent from respirations gradually over 1 to 2 years. The latencies of the motor potentials evoked by cortical and thoracic root magnetic stimulation decreased gradually over 2 to 3 years. Motor cortex mapping of the reinnervated biceps muscle showed a gradual change over 4 to 33 months from the area of the intercostal muscles to that of the arm area, which was more lateral on the motor cortex. These findings suggest that reorganization of the motor cortex to arm flexor muscles occurs following peripheral nerve anastomosis.