Competitive inhibition of the luminal efflux by multidrug and toxin extrusions, but not basolateral uptake by organic cation transporter 2, is the likely mechanism underlying the pharmacokinetic drug-drug interactions caused by cimetidine in the kidney

Cimetidine, an H₂ receptor antagonist, has been used to investigate the tubular secretion of organic cations in human kidney. We report a systematic comprehensive analysis of the inhibition potency of cimetidine for the influx and efflux transporters of organic cations [human organic cation transporter 1 (hOCT1) and hOCT2 and human multidrug and toxin extrusion 1 (hMATE1) and hMATE2-K, respectively]. Inhibition constants (K(i)) of cimetidine were determined by using five substrates [tetraethylammonium (TEA), metformin, 1-methyl-4-phenylpyridinium, 4-(4-(dimethylamino)styryl)-N-methylpyridinium, and m-iodobenzylguanidine]. They were 95 to 146 μM for hOCT2, providing at most 10% inhibition based on its clinically reported plasma unbound concentrations (3.6-7.8 μM). In contrast, cimetidine is a potent inhibitor of MATE1 and MATE2-K with K(i) values (μM) of 1.1 to 3.8 and 2.1 to 6.9, respectively. The same tendency was observed for mouse Oct1 (mOct1), mOct2, and mouse Mate1. Cimetidine showed a negligible effect on the uptake of metformin by mouse kidney slices at 20 μM. Cimetidine was administered to mice by a constant infusion to achieve a plasma unbound concentration of 21.6 μM to examine its effect on the renal disposition of Mate1 probes (metformin, TEA, and cephalexin) in vivo. The kidney- and liver-to-plasma ratios of metformin both were increased 2.4-fold by cimetidine, whereas the renal clearance was not changed. Cimetidine also increased the kidney-to-plasma ratio of TEA and cephalexin 8.0- and 3.3-fold compared with a control and decreased the renal clearance from 49 to 23 and 11 to 6.6 ml/min/kg, respectively. These results suggest that the inhibition of MATEs, but not OCT2, is a likely mechanism underlying the drug-drug interactions with cimetidine in renal elimination.

A long-term follow-up study of radiographically evident degenerative changes in the temporomandibular joint with different conditions of disk displacement

The purpose of this retrospective study is to assess the relationship between an initial and persisting condition of disk displacement (DD) and the long-term course of radiographically evident degenerative changes of the temporomandibular joint (TMJ). Nineteen patients agreed to a radiographic follow-up examination of 29 joints and were included in this study. The joints were radiographically assessed at the first visit and at least 46 months after the first visit (mean 89.3 months). At the time of the follow-up, all subjects had a good clinical course after a favorable response to the treatments. There were significant relationships between the initial diagnosis of DD and the interval change in the morphology of the articular eminence. The articular eminence became flattened or deformed only in the joints with persistent DD without reduction. And there was a tendency that the condyle became smaller in the joints initially with permanent DD and in the joints which show a progression in the disk-condylar relationship. The results of this study suggested that, in the joints with persisting non-reducing disk displacement, flattening and deformation of the articular eminence and regression of the condylar size were likely to happen even after symptoms and signs of TMJ disorders were resolved or reduced.

Polymorphism of the lipoprotein lipase gene and risk of atherothrombotic cerebral infarction in the Japanese

BACKGROUND AND PURPOSE

Lipid and lipoprotein abnormalities have been implicated in the pathogenesis of ischemic cerebrovascular disease and atherosclerosis. Lipoprotein lipase (LPL) plays an important role in plasma lipoprotein metabolism. Several studies have recently reported the presence of a relationship between Ser447Stop mutation of LPL and coronary artery disease. Other polymorphisms (HindIII and PvuII) of the LPL gene have already been shown to correlate significantly with dyslipidemia. We investigated whether these polymorphisms are associated with increased risk of ischemic cerebrovascular disease (CVD).

METHODS

We recruited 177 CVD patients (atherothrombotic infarction, n=71; cardioembolic infarction, n=30; lacunar infarction, n=76) and 177 healthy control subjects. Subjects were genotyped for the Ser447Stop mutation and for HindIII/PvuII restriction fragment length polymorphisms of the LPL gene, and the findings were investigated for associations with the clinical subtypes of CVD and with lipid levels.

RESULTS

The Ser447Stop mutation correlated significantly with CVD (0.107 versus 0.158; P=0.035). For the CG+GG versus CC genotype, the odds ratio between control subjects and CVD patients with atherothrombotic infarction was 0.42 (95% CI, 0.18 to 0.99) (P=0.046). Serum HDL cholesterol and triglyceride levels did not correlate significantly with the Ser447Stop genotype. HindIII polymorphism correlated significantly with CVD (0.234 versus 0.169; P=0.031), but the frequency of PvuII polymorphism was not significantly different between groups.

CONCLUSIONS

Our results suggest that the Ser447Stop mutation of the LPL gene is a novel genetic marker for low risk of atherothrombotic cerebral infarction.

PARKIN as a pathogenic gene for autosomal recessive juvenile parkinsonism

Parkinson's disease is a common neurodegenerative disease with complex clinical features. Recently, we idenfied a novel gene named Parkin to be responsible for the pathogenesis of autosomal recessive juvenile parkinsonism (AR-JP). Various mutations were found in AR-JP patients of Japanese and other ethnic origins, providing a definitive evidence for the Parkin to be a causative gene for AR-JP. The predicted structure of Parkin protein and its mutation provide important clues for studying the functional role of the Parkin protein in leading to selective degeneration of nigral neurons in the brains of AR-JP patients.

Solution structure of Grb2 reveals extensive flexibility necessary for target recognition

Grb2 is an adaptor protein composed of a single SH2 domain flanked by two SH3 domains. Grb2 functions as an important evolutionary conserved link between a variety of cell membrane receptors and the Ras/MAP kinase-signaling cascade. Here, we describe the solution structure of Grb2 as revealed by NMR and small angle X-ray scattering measurements. We demonstrate that Grb2 is a flexible protein in which the C-terminal SH3 domain is connected to the SH2 domain via a flexible linker. This is in contrast to the previously described Grb2 crystal structure, which showed a compact structure with intramolecular contact between two SH3 domains. Binding experiments on Grb2 and peptides containing two different proline-rich sequences indicate that Grb2 adapts the relative position and orientation of the two SH3 domains to bind bivalently to the target peptide sequences.

Development of the nosological analysis of juvenile parkinsonism

In the nosological viewpoint concerning diseases with a pathophysiological dysfunction of the nigro-striatal dopaminergic system, juvenile parkinsonism (JP) is discussed in this paper in relation to hereditary progressive dystonia (HPD) and Parkinson's disease (PD). Most cases of JP have dystonia with parkinsonism, which is the main symptom of HPD. In the symptomatological analysis of complication with dystonia, an interesting observation arose as regards on the anatomical and functional development of the basal ganglia through patients with childhood onset HPD and JP. Genetic analysis revealed the disease entity of HPD to be an abnormality of the GTP-CH I gene. Consequently, it has been clarified that clinical differences between HPD and JP were not merely derived from differences in developmental processes. Furthermore, the autosomal recessive type of JP (AR-JP) was confirmed to be a disease entity by the detection of an abnormality of the 'parkin' gene. The nosological controversy about JP and PD in the clinical standpoint has been clarified. However, as more than half of patients with JP do not carry a mutation in the 'parkin' gene, more investigations concerning nosological entities should be carried out. The absence of Lewy bodies in most patients with AR-JP has been confirmed to be a characteristic neorupathological finding as compared with those with typical PD pathology. In this paper, we discuss the above findings.

Levodopa effective parkinsonism associated with aqueductal stenosis: a case report and review of the literature

A case of aqueductal stenosis (AS) associated with marked parkinsonism is described. A ventriculoperitoneal (V-P) shunt was performed in an 18-year-old female because of hydrocephalus associated with non-neoplastic aqueductal stenosis. The patient developed acute parkinsonism with Parinaud's sign after the shunt revision. She had a marked response to levodopa and the parkinsonism improved. Subsequently, levodopa therapy was gradually discontinued without any manifestation of parkinsonism. The pathophysiology of this type of parkinsonism probably involved presynaptic dopaminergic dysfunction. However, the etiology of this complication has not been confirmed.

Molecular genetic analysis of a novel Parkin gene in Japanese families with autosomal recessive juvenile parkinsonism: evidence for variable homozygous deletions in the Parkin gene in affected individuals

Autosomal recessive juvenile parkinsonism (AR-JP) is a distinct clinical and genetic entity characterized by selective degeneration of nigral dopaminergic neurons and young-onset parkinsonism with remarkable response to levodopa. Recently, we mapped the gene locus for AR-JP to chromosome 6q25.2-q27 by linkage analysis and we identified a novel large gene, Parkin, consisting of 12 exons from this region; mutations of this gene were found to be the cause of AR-JP in two families. Now we report results of extensive molecular analysis on 34 affected individuals from 18 unrelated families with AR-JP. We found four different homozygous intragenic deletional mutations, involving exons 3 to 4, exon 3, exon 4, and exon 5 in 10 families (17 affected individuals). In addition to the exonic deletions, we identified a novel one-base deletion involving exon 5 in two families (2 affected individuals). All mutations so far found were deletional types in which large exonic deletion accounted for 50% (17 of 34) and the one-base deletion accounted for 6% (2/34); in the remaining, no homozygous mutations were found in the coding regions. Our findings indicate that loss of function of the Parkin protein results in the clinical phenotype of AR-JP and that subregions between introns 2 and 5 of the Parkin gene are mutational hot spots.

[Slowly progressive dressing and constructional apraxia: symptomatological study, especially for dressing apraxia]

In 1982, Mesulam drew attention to a clinical picture characterized by slowly progressive aphasia without dementia, and since then, there have been many such reports. Recently, there have been 30 reports of slowly progressive apraxia. However, the nature of this apraxia is not uniform. We now report a patient with slowly progressive dressing and constructional apraxia. The patient is a 60-year-old right-handed woman with a 2-year history of a slowly progressive praxic disturbance. On admission, she was alert and aware of this difficulty. A neurological examination disclosed mild rigidity and myoclonus in her left hand. A neuropsychological assessment disclosed severe dressing apraxia, which was unlikely to be caused by dementia and moderate constructional apraxia. Her dressing apraxia was manifested in upper limbs, neck, trunk and lower limbs. However, she could express verbally the action of dressing. She also showed mild limb-kinetic apraxia, but neither ideational apraxia nor ideomotor apraxia was present. Aphasia and agnosia were also absent. On an MRI, the bilateral cerebral hemispheres were atrophic (right > left). A 99m-Tc ECD SPECT revealed decreased uptake in the right cerebral hemisphere and left frontal lobe, and an EEG showed slow waves over the right cerebral hemisphere. There have been 30 reports of slowly progressive apraxia. Most of these cases presented with slowly progressive clumsiness in one or both hands as an initial symptom, followed by constructional, ideomotor or dressing apraxia. Our patient differed from these cases in that dressing and constructional apraxia progressed slowly without any other apraxia except only mild limb-kinetic apraxia. There was a similarity between dressing apraxia of our patient and that of Marie's and Brain's original cases.

Pathologic and biochemical studies of juvenile parkinsonism linked to chromosome 6q

We report the results of pathologic and biochemical studies in a patient with 6q-linked autosomal recessive juvenile parkinsonism (AR-JP). Neuronal loss and gliosis were restricted to the substantia nigra and the locus ceruleus. No Lewy bodies were found, but neurofibrillary tangles and argyrophilic astrocytes were seen in the cerebral cortex and brainstem nuclei. The later findings, which have not been reported previously in AR-JP, suggest the pathologic heterogeneity of 6q-linked AR-JP.

Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism

Parkinson's disease is a common neurodegenerative disease with complex clinical features. Autosomal recessive juvenile parkinsonism (AR-JP) maps to the long arm of chromosome 6 (6q25.2-q27) and is linked strongly to the markers D6S305 and D6S253; the former is deleted in one Japanese AR-JP patient. By positional cloning within this microdeletion, we have now isolated a complementary DNA done of 2,960 base pairs with a 1,395-base-pair open reading frame, encoding a protein of 465 amino acids with moderate similarity to ubiquitin at the amino terminus and a RING-finger motif at the carboxy terminus. The gene spans more than 500 kilobases and has 12 exons, five of which (exons 3-7) are deleted in the patient. Four other AR-JP patients from three unrelated families have a deletion affecting exon 4 alone. A 4.5-kilobase transcript that is expressed in many human tissues but is abundant in the brain, including the substantia nigra, is shorter in brain tissue from one of the groups of exon-4-deleted patients. Mutations in the newly identified gene appear to be responsible for the pathogenesis of AR-JP, and we have therefore named the protein product 'Parkin'.

Localization of a gene for an autosomal recessive form of juvenile Parkinsonism to chromosome 6q25.2-27

An autosomal recessive form of juvenile Parkinsonism (AR-JP) (MIM 600116) is a levodopa-responsive Parkinsonism whose pathological finding is a highly selective degeneration of dopaminergic neurons in the zona compacta of the substantia nigra. By linkage analysis of diallelic polymorphism of the Mn-superoxide dismutase gene (SOD2), we found a family with AR-JP showing perfect segregation of the disease with the SOD2 locus. By extending the linkage analysis to 13 families with AR-JP, we discovered strong evidence for the localization of the AR-JP gene at chromosome 6q25.2-27, including the SOD2 locus, with the maximal cumulative pairwise LOD scores of 7.26 and 7.71 at D6S305 (theta = .03) and D6S253 (theta = .02), respectively. Observation of obligate recombination events, as well as multipoint linkage analysis, placed the AR-JP gene in a 17-cM interval between D6S437 and D6S264. Delineation of the AR-JP gene will be an important step toward our understanding of the molecular mechanism underlying selective degeneration of the nigral neurons.

Effects of tolcapone, a catechol-O-methyltransferase inhibitor, on motor symptoms and pharmacokinetics of levodopa in patients with Parkinson's disease

The effects of tolcapone, a catechol-O-methyltransferase inhibitor, on the bioavailability and efficacy of levodopa were evaluated in 12 patients with Parkinson's disease (PD), 8 of whom showed signs of daily motor fluctuations (wearing-off phenomenon). Motor disabilities were assessed in 12 patients at 7 time points before and after the chronic administration of tolcapone using the Unified Parkinson's Disease Rating Scale (UPDRS). The UPDRS score was improved at all points of determination. Eight patients with wearing-off phenomenon on levodopa showed symptomatic improvement on the combination. The area under the curve (AUC) for levodopa increased by 34% (p = 0.0059) after the administration of tolcapone. The elimination half-life (T1/2) of levodopa was significantly prolonged by 81% (p = 0.0001) after the treatment. The AUC of 3-O-methyldopa, a metabolite of levodopa, was decreased by 79% (p = 0.0001) and the Cmax (maximum concentration) was also decreased by 80%d after the administration (p = 0.0001) of tolcapone. The combination of tolcapone and levodopa was well tolerated. Our findings suggest that tolcapone improves the pharmacokinetics of levodopa in plasma and motor symptoms of fluctuating PD patients. It is suggested that tolcapone may be useful drug adjunct to levodopa in treating patients with PD with wearing-off phenomena.

Familial juvenile parkinsonism

Some cases of parkinsonism without Lewy bodies were detected, although the presence of Lewy bodies is a diagnostic criterion for PD. Thereafter, similar cases were repeatedly encountered by researchers at Juntendo University, Tokyo. Groups in Niigata and Hiroshima also reported cases of parkinsonism without Lewy bodies, which suggests that such cases occur frequently in Japan. Clinically, most of these are cases of typical juvenile parkinsonism (JP) and have sufficient response to levodopa therapy. Diurnal motor fluctuations were mentioned in some reports. The clinical findings vary slightly from case to case but the primary pathological finding is restricted to the substantia nigra. Therefore, JP almost certainly results from a dopamine deficiency in the nigrostriatal system. However, the absence of Lewy bodies raises the possibility of differences in the degenerative process from a general pathology of the substantia nigra with the Lewy bodies. Many cases without Lewy bodies are familial cases with autosomal recessive (AR) inheritance. Both factors may be integrated in a single disease although this is still uncertain. Families in which JP appeared to be inherited in an autosomal dominant (AD) manner as well as those in which it appeared to be inherited in an AR manner were identified. The onset ages of the probands were slightly higher in the former than in the latter families. The age of onset in AD inheritance family cases may coincide with an age of onset of typical JP due to anticipation of the disease. The sporadic cases, which account for half of the JP cases, require further analysis.

[Definition and nosological concept of juvenile parkinsonism]

Clinicopathological identification of juvenile parkinsonism(JP) was described in reference to Dopa-responsive syndrome or to dopamine-dependent disorders. Recently, hereditary progressive dystonia(HPD), a dopamine-dependent disorder, was identified as a nosological entity from JP and Parkinson's disease(PD) by discovery of mutations of the gene. JP includes young onset Parkinson's disease(YOPD) and idiopathic JP with much younger-onset cases. YOPD belongs to PD-nosology based on clinical and pathological findings of our own autopsied cases. However, the idiopathic JP' might involve independent pathophysiological changes. Namely, cases of the JP are associated with atypical pathological findings with lack of Lewy body or hypoplasia of the substantia nigra and specific clinical manifestations of autosomal recessive trait and of dystonic feature and diurnal fluctuation of the symptoms.

Injection of a GABA antagonist into the mesopontine reticular formation abolishes haloperidol-induced catalepsy in rats

THE pedunculopontine nucleus and its adjacent structure of the mesopontine reticular formation are known as a mesencephalic locomotor region, since either electrical or chemical stimulation of these regions induces locomotion in decerebrate animals. In parkinsonism, it is presumed that the pedunculopontine nucleus is under GABAergic overinhibition from the basal ganglia. To reveal the behavioural effects of GABAergic disinhibition of the mesopontine reticular formation in parkinsonism, picrotoxin, a GABAA antagonist, (5 or 10 ng/ 0.25 microliter) or vehicle was injected unilaterally into the mesopontine reticular formation of rats via implanted cannulae after induction of catalepsy using haloperidol (1.5 mg kg-1, i.p.). Injection of the larger dose of picrotoxin, but not the smaller dose nor the vehicle, abolished the catalepsy with or without spontaneous locomotor activity. The present result suggests that the disinhibition of the brainstem output structures contributes to the recovery of mobility in the cataleptic state induced by blocking the dopaminergic transmission of the basal ganglia.

[A 43-year-old woman with 18 years history of parkinsonism]

We report a 43-year-old woman who died after 18 years history of parkinsonism. She was well until 25 years of the age (1976) when she noted a difficulty in stepping her feet. In the next year, she started to drag her feet. She was treated with levodopa with good response, however, she developed dyskinesia when she was 33 years of the age. She was evaluated in another hospital in 1984. She showed normal intelligence, normal ocular movement, masked face, small voice, small step gait, stooped posture, freezing of the gait, retropulsion, and cogwheel rigidity in limbs. No tremor or ataxia was noted. She received left ventrolateral thalamotomy at that time. Rigidity on the right side markedly reduced, however, she continued to show bradykinesia and motor fluctuations. On August 1 of 1994, she developed fever of 40 degrees C and dyspnea. On the next day, she expired from acute respiratory distress. She was able to walk unsupported until just before her last admission. The patient was discussed in a neurological CPC. The chief discussant arrived at the conclusion that this patient had Lewy body-positive young onset Parkinson's disease. Opinions were divided into two groups, i.e., young onset Lewy-body positive Parkinson's disease and Lewy-body negative young onset parkinsonism. Post-mortem examination revealed moderate loss of pigmented neurons in the substantia nigra more in the ventro-lateral part. Lewy bodies were found in the remaining neurons. Lewy bodies were more frequently seen in the locus coeruleus, although neuronal loss was less prominent in the locus coeruleus. The dorsal vagal motor nucleus showed moderate loss of neurons. Otherwise, the central nervous system was unremarkable. To our knowledge, this patient had the second youngest age of the onset so far reported in the literature for Lewy-body positive typical Parkinson's disease.

[A 62-year-old man with familial parkinsonism with the onset at 24 years of the age]

We report a right-handed 62-year-old man with early onset familial parkinsonism. The patient was well until 24 years of the age when he noted an onset of resting tremor in his right hand. During the next four years, he noted rigidity, bradykinesia, and difficulty in walking. He was seen in another hospital at 28 years of the age, where he received left pallidotomy. Rigidity on the left side showed marked improvement. He received right pallidotomy at age 30 years. He developed right hemiplegia after this surgery. He was admitted to our hospital in March, 1983 when he was 51 years of the age. He was treated with levodopa but improvement was rather of minor degree. He was transferred to another hospital, but his motor disturbance progressed slowly, and was admitted again to our hospital in November 1990. He had 6 siblings 4 of whom including himself suffered from parkinsonism. No consanguinity was noted in parents. On admission, he appeared chronically ill but the general physical examination was unremarkable. Neurologic examination revealed an alert and mentally sound man. Hasegawa dementia scale was 28.5/32.5. Upward gaze was slightly restricted (3/5). Cranial nerve examination revealed oculogyric crisis, apraxia of eyelid opening, masked face, and small voice. He was able to stand with support; his posture showed left-ward leaning. He had right hemiparesis with moderate weakness. He showed marked bradykinesia and moderate rigidity in his left upper extremity. Fine postural tremor was noted in the left hand. Deep tendon reflexes were diminished in the upper extremities. No Babinski sign was noted. Pain sensation was somewhat diminished on the right side. Results of routine laboratory examination were unremarkable. Cranial CT scan revealed atrophy in the frontal lobe, particularly in the prefrontal area. In addition, MRI revealed T1-and-T2-low signal intensity lesions in the right ventral pallidal region and in the left ventrolateral thalamic-hypothalamic areas. He was treated with 600 mg of levodopa with benserazide and 22.5 mg of bromocriptine with mild to moderate improvement in his bradykinesia and rigidity. He was discharged in January 1991. His clinical course was complicated by intestinal obstruction in October, 1994. He was admitted to another hospital where he was operated on the obstruction on November 5, 1994. The sigmoid colon was markedly dilated but no mass was found. Postoperative course was uneventful until November 18, 1994 when he was found dead in his hospital room shortly after 4 am. The patient was discussed in neurological CPC, and the chief discussant arrived at the conclusion that the patient had young-onset familial Lewy body-negative parkinsonism. Opinions were divided between Lewy body-positive familial Parkinson's disease and Lewy body negative young onset parkinsonism. Postmortem examination revealed aspiration pneumonia, which appeared to be the cause of his death, in the right lung. Neuropathologic examination revealed loss of malanized neurons in the substantia nigra and the locus coeruleus. In the substantia nigra, neuronal loss was particularly severe in the ventrolateral area. No Lewy bodies were seen. The dorsal motor nucleus of the vagal nerve was well preserved. Stereotaxic lesions involved bilateral thalamic areas. This patient appears to represent a case of autosomal recessive juvenile parkinsonism (AR-JP). Early onset, superb response to levodopa, sleep effect, and easy development of dyskinesias and motor fluctuations characterize AR-JP. The reason why this patient did not show these clinical features is probably bilateral sterotaxic surgeries. Particularly, the second surgery was complicated by right hemiparesis. His siblings who developed parkinsonism showed typical clinical features of AR-JP.

GTP-cyclohydrolase I gene mutations in hereditary progressive amd dopa-responsive dystonia

Recently, mutations of the GTP-cyclohydrolase I (GTP-CH I) gene, which catalyzes the first step in the tetrahydrobiopterin (BH4) biosynthesis, were discovered in Japanese patients with hereditary progressive dystonia/dopa-responsive dystonia (HPD/DRD). However, it has not been confirmed that non-Japanese patients also contain mutations in the same gene, or whether these mutations are specific to HPD/DRD. In this study, two novel nonsense mutations in exon I of the GTP-CH I gene and a new mutation at the splice acceptor site of intron I were identified in an autopsied case of English-Irish descent and 2 Japanese patients with HPD/DRD. In the latter, cerebrospinal fluid (CSF) neopterin levels (which may reflect the GTP-CH I activity in the brain) were reduced to 18% and 37% of controls. A therapeutic trial of oral BH4 was ineffective, however, in a genetically proven patient. In contrast, no mutations in any exons of the GTP-CH I gene were found in 2 patients with early-onset parkinsonism with dystonia (EOP-D) who developed dopa-responsive parkinsonism and dystonia at 6 and 8 years old, respectively. Neopterin levels in CSF were well preserved in 6 EOP-D patients. These data suggest that, among patients of different racial backgrounds, the pathogenesis of HPD/DRD, unlike EOP-D, involves partial reduction of the brain GTP-CH I activity consequent to mutations in the GTP-CH I gene. Measurement of CSF neopterin concentration may be useful for the differential diagnosis between HPD/DRD and EOP-D.

GTP cyclohydrolase I activity in mononuclear blood cells in juvenile parkinsonism

GTP cyclohydrolase I activity in mononuclear blood cells from patients with juvenile parkinsonism (JP) was found to be normal compared to healthy controls. The normal activity in JP contrasts strongly with the decreased activity of 2-20% normal levels in hereditary progressive dystonia with marked diurnal fluctuation (HPD) or dopa responsive dystonia (DRD). The result indicates that the decreased dopamine level in the basal ganglia in JP is not due to decreased activity of GTP cyclohydrolase I, the enzyme for the biosynthesis of the tetrahydrobiopterin cofactor of tyrosine hydroxylase (TH), and the enzyme activity in mononuclear blood cells could be a reliable method for differential diagnosis between JP and HPD/DRD.

Motor function of infants with spastic hemiplegia

The motor function of 25 children with spastic hemiplegia was examined retrospectively using videotapes recorded at 2-8 months of age. Many infants showed deficient forward movement of the arm and deficient opening of the hand on the affected side. At 7 and 8 months of age, whether the hand was semiflexed or clenched was correlated with the later upper extremity function. In the prone position, most could support their weight on the flexed arm on the affected side. In the supine position, half of the infants could not extend the knee on the affected side. At 2 months of age, asymmetry of the upper and lower extremity movements was not identified. Persistent primitive reflexes and abnormal truncal muscular tone were not recognized in the hemiplegic infants, and did not seem to be signs predicting hemiplegic cerebral palsy.

[A 77-year-old woman with myoclonus and epilepsy]

We present a 77-year-old woman with myoclonus and epilepsy. She was well until 35 years of age, when she noted an onset of trembling of the legs upon standing. Her symptom slowly progressed, and she felt a difficulty in standing when she was 39-year-old. She had a major motor seizure without an apparent focal onset when she was 46-year-old. She also developed tremor in her hands, and she felt difficulty in holding a glass filled with water. She was admitted to our service for the first time in 1965 when she was 51-year-old. She showed wide-based ataxic gait with truncal titubation. In finger to nose test, myoclonic jerks were induced in the upper extremities. Otherwise neurological examination was unremarkable. She was treated with primidone and phenobarbital, and was discharged for out patient follow up. Her symptoms slowly progressed, and gait and station became more difficult. Mentally she was sound. Three months prior to the present admission, she developed more difficulty in gait, and decrease in food intake. On the 14th of September in 1991, she was seen by a local physician who found an abnormal shadow in her chest X-ray, and she was admitted to our service for further work-up on September 18, 1991. On admission, the patient was a chronically ill and emaciated woman. Her blood pressure was 140/84 mmHg, heart rate 115/minutes and regular, and the body temperature 36.9 degrees C. The palpebral conjunctivae were anemic. No cervical adenopathy was noted. The lung fields were clear, and no heart murmur was audible. The abdomen was soft, and no organomegaly was present. On neurologic examination, she looked somnolent with disorientation to time and place. Her memory was poor, and she could not do well serial 7s. The disc was flat and the ocular movements appeared intact. Other cranial nerves were also unremarkable. She showed diffuse muscle wasting. She was unable to stand or walk. Maintaining the sitting position was also difficult. She was able to raise her arms, but almost unable to move her lower extremities. The precise muscle testing was impossible. No abnormal involuntary movement was seen. Finger to nose test could not be performed.(ABSTRACT TRUNCATED AT 400 WORDS)

An early cytoplasmic change before Lewy body maturation: an ultrastructural study of the substantia nigra from an autopsy case of juvenile parkinsonism

Neurons containing a central pale area which may possibly represent an early cytoplasmic change before Lewy body maturation were observed in the substantia nigra from a rare autopsy case of juvenile parkinsonism. Ultrastructurally, such neurons exhibited cytoplasmic swelling along with disappearance of the rough endoplasmic reticulum from the central part of the perikaryon. The pale central cytoplasm was replaced by numerous-cored vesicles, mitochondria, ribosome-like granules and a few Lewy body filaments. The relation of this central pale area to the pale body is discussed.

New pathologic observations in juvenile onset parkinsonism with dystonia

A patient with hereditary juvenile onset parkinsonism with dystonia died at age 39. There were Lewy bodies and regionally selective neuronal damage in the substantia nigra pars compacta. These changes closely resemble those seen in Parkinson's disease, and emphasize the selective vulnerability of the ventral tier of the pars compacta in these degenerations.

Juvenile parkinsonism: a case with first clinical manifestation at the age of six years and with neuropathological findings suggesting a new pathogenesis

A clinico-pathological study of a 39-year-old female with Juvenile parkinsonism was carried out. Although the clinical manifestations were consistent with parkinsonism, the pathological findings were significantly different. Pathological examination showed the lesion to be localized to the substantia nigra, the number of neurons to be abnormally low, the proportion of melanin-containing cells to be reduced, and a large number of immature cells to be present. No neuronal degeneration associated with gliosis or release of melanin granules, such as seen in Parkinson's disease, was observed. Neuropathological studies, including cytometry and comparison against normal controls in the distribution of melanin granules, suggested hypoplasia and poor neuronal maturation of the substantia nigra. Since neuromelanin is thought to be the result of normal dopamine metabolism, reduction of melanin-containing cells in this case suggests inadequate or abnormal dopamine metabolism. Thus, the clinical manifestation of parkinsonism in this case seems to be related to the small number of melanin-containing cells which implies the dopamine deficiency state.

Hemiparesis caused by vertebral artery compression of the medulla oblongata. Case report

The case is reported of a patient with progressive left hemiparesis due to vascular compression of the medulla oblongata. Metrizamide computerized tomography cisternography revealed that the left vertebral artery was compressing and distorting the left lateral surface of the medulla. Compression was surgically relieved and symptoms improved postoperatively. Neurological and symptomatic considerations are discussed in relation to the topographical anatomy of the lateral corticospinal tract.

Estimation of generator potentials in primary spindle endings evoked by brief tendon taps in man

The ligamentum patellae in human subjects was tapped by a random triangular waveform, while single primary spindle afferent spikes were recorded from the femoral nerve. Cross-correlation between the primary spindle afferent spikes and the taps revealed a prominent peaked distribution of the discharge probability. The cross-correlograms showed that response time from the onsets of taps to the afferent spike was 7.5 +/- 0.6 msec in 6 units and that the width between the feet of the peaked distribution was 3.3 +/- 0.2 msec in 6 units. The width of the peak implies jitter of the response time of the primary spindle spikes which appear to correspond with the time-to-peak of generator potentials elicited by the taps in primary endings of muscle spindles. Integration of the peaked distribution showed a slow slope at the beginning and near the summit and a steep slope on the way. This curve is assumed to represent the rising phase of the generator potentials in primary spindle endings.

[Electromyographic analysis on juvenile muscular atrophy of unilateral upper extremity (author's transl)]

In 1959, this disorder was first reported by one of authors (K.H.) (6). Since then, many Japanese cases have been reported and recently some cases are also reported in other countries. Its cause and pathology are still unknown, because no autopsy case was obtained. In this report, some electromyographic findings are described and discussed. This series contain 26 cases (male 23, female 3). Age of onset: 13-33 years old (mean 19.4 years old). Clinical duration: 2-32 years old (mean 9.0 years). Only 6 cases (23%) showed trauma as the past history (Table 2). We classified 26 cases in three groups (UL: unilateral, BP: bilateral, one-side predominant, BS: bilateral symmetrical) based on the laterality of physical findings (amyotrophy, weakness, finger tremor, etc.) (Table 3). Conventional needle EMG were done in all cases and these findings were judged by the criteria which we defined as Fig. 2. In some cases, conduction velocity (MCV & SCV) were measured. Needle EMG showed more selective and localized distribution of NGP (neurogenic pattern) in the hand muscles, the forearm muscles except for M. brachioradialis, and M. triceps brachii on the atrophied sides of the arm in all clinical groups (UL, BP, BS) (Table 4.5). On the normal side of bilaterally examined cases of UL group, NGP was shown in 9/11 cases, buts its distribution seemed to be slightly restricted in the more distal part. Thus, in this disorder, 22/26 cases (77%) were electromyographically affected on the bilateral sides, although the clinical feature was mostly unilateral. The clinical features and pathological process seemed to be established in a few years after the onset without the apparent tendency of further progression. Afterwards, no apparent extension of NGP distribution and increment of grading were observed in the Clinical course. No delay was observed on MCV and SCV. The pathological lesions responsible for these electromyographic changes are discussed, either on spinal segmental origin or on brachial plexus origin, but some ambiguous portions are still remained.

A clinical study of tuberculous colitis

During the last 8 years, the diagnosis of tuberculous colitis has been made radiologically in 22 cases. Twelve were confirmed by histological or bacteriological evidences. The X-ray findings are classified into three types as follows: Type A, showing an extensive scarred area in the ileocecum and ascending colon. Type B, showing annular stricture in the ascending colon and dilatation of its oral side. Type C, showing pouchformation (pseudo-diverticulum) and deformity in the cecum. We emphasize that histological examination and culture of the biopsy specimens by endoscopy were useful for the diagnosis of tuberculous colitis. Furthermore, radiologic changes of the colon by administration of antituberculous drugs were observed.