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Biomedical subjects

I Nakano

Publications and source records attributed to I Nakano.

At least 73 records · Page 4Linked to original sources
PubMed2000

Long-term follow-up of sustained responders to interferon therapy, in patients with chronic hepatitis C.

Interferon (IFN) therapy has been proven to induce the normalization of serum alanine aminotransferase (ALT) levels and to eradicate the hepatitis C virus (HCV) in some patients with chronic hepatitis C, and these patients are usually defined as 'sustained responders'. However, there have been some reports of hepatocellular carcinoma (HCC) in these patients, and the development of HCC remains life-threatening in patients who clear HCV. We analysed the long-term prognoses of patients with chronic hepatitis C in whom HCV was eradicated with IFN. We investigated 392 sustained responders to IFN therapy, from 1,277 patients with chronic HCV infection who received IFN treatment at one of our institutions between April 1989 and March 1999. We analysed the medical records and looked for the development of HCC. About 30% of the sustained responders had been lost to follow-up 3 years after the end of IFN therapy, and the follow-up rate of sustained responders was significantly lower than that of non-sustained responders (P < 0.0001). HCC were found in eight patients: in seven patients HCC developed within 5 years after completion of IFN therapy; but in one patient, a single HCC less than 3 cm in diameter was detected between 7 and 8 years after completion of IFN. Of the five patients who had regular medical follow-up, the HCC was solitary, and the patients survived without any evidence of recurrence. Of the three patients who had not been followed-up, two died from HCC and HCC recurred in the third. These results suggest that HCC can develop in sustained responders and that sustained responders should be followed-up closely after completion of IFN so that HCC may be detected at an early stage. The optimal duration of the follow-up period of the sustained responders remains unclear. Additional prospective studies are required in order to establish an appropriate follow-up protocol for sustained responders to IFN.

Adolescent↗
PubMed2000

Frontotemporal dementia with motor neuron disease (amyotrophic lateral sclerosis with dementia).

Frontotemporal dementia (FTD) with motor neuron disease means amyotrophic lateral sclerosis (ALS) with dementia. In the cerebrum of this condition, the medial cortex of the rostral temporal lobe is constantly and most remarkably involved. Another constant and quite characteristic lesion is neuronal loss localized to the CA1-subiculum transitional area at the level of the pes hippocampi. The rostral portion of the parahippocampal gyrus, and the amygdaloid nucleus are also involved. Ubiquitinated intracytoplasmic inclusions are seen in the dentate granule cells and parahippocampal gyrus neurons. Some cases of ALS without dementia show the identical temporal lobe degeneration as well as the cortical ubiquitinated inclusions, thus raising the possibility of overlooked dementia or premature death of the patients. Similarly, recently proposed motor neuron disease-inclusion dementia may be a forme fruste of ALS with dementia.

Amyotrophic Lateral Sclerosis↗
PubMed2000

An autopsy case of Alzheimer's disease with a progressive supranuclear palsy overlap.

A 74-year-old man developed abnormal forgetfulness, soon followed by unstable speech content and marked disorientation. At 77 years of age, the patient started to occasionally fall, an aspect of progressive supranuclear palsy. He then became bedridden. The patient eventually died of pneumonia at 79 years of age. Neuropathological examination revealed profiles of both progressive supranuclear palsy and Alzheimer's disease. Although the two conditions both belong to tauopathy, their pathologically proven combination was rare. Furthermore, the case had the possibility of being a subgroup of tauopathy.

Aged↗
PubMed2000

New consensus research on neuropathological aspects of familial amyotrophic lateral sclerosis with superoxide dismutase 1 (SOD1) gene mutations: inclusions containing SOD1 in neurons and astrocytes.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that primarily involves the motor neuron system. Approximately 5-10% of ALS is familial. Superoxide dismutase 1 (SOD1) gene mutations are shown to be associated with about 20% of familial ALS (FALS) patients. The neuronal Lewy-body-like hyaline inclusion (LBHI) and astrocytic hyaline inclusion (Ast-HI) are morphological hallmarks of certain SOD1-linked FALS patients with SOD1 gene mutant and transgenic mice expressing human SOD1 with G85R mutation. From the detailed immunohistochemical analyses, the essential common protein of both inclusions is SOD1. Ultrastructurally, both inclusions consist of granule-coated fibrils 15-25 nm in diameter. Based on the immuno-electron microscopical finding that these abnormal granule-coated fibrils are positive for SOD1, the formation (or aggregation) of the abnormal fibrils containing SOD1 would be essential evidence in diseases caused by various SOD1 mutations. The granule-coated fibrils are also modified by advanced glycation end products (AGEs). The AGEs themselves are insoluble molecules with direct toxic effects on cells. AGE formation of SOD1 composing the granule-coated fibrils (probable AGE-modified mutant SOD1) may amplify their aggregation and produce a more marked toxicity.

Amyotrophic Lateral Sclerosis↗
PubMed2000

Difficulty of early diagnosis of amyotrophic lateral sclerosis: Japanese case studies.

An early diagnosis of amyotrophic lateral sclerosis can be difficult to establish in patients with atypical features such as unilateral crural amyotrophy or showing motor symptoms and signs of overlapping conditions like cervical spondylosis, unless these patients are followed over long periods of time. Here we describe three such cases from our hospital in Japan.

Aged↗
PubMed2000

Lipid peroxidation levels in rat cardiac muscle are affected by age and thyroid status.

Free radicals, hydroxyperoxides and H(2)O(2) are all known to damage cell components. This study was designed to compare the concentrations of hydroxyperoxide and free radical scavengers in the cardiac muscles of old rats in the hyper- or hypothyroid condition, to determine whether rates of peroxidation would differ with age, thyroid status, or both. Rats were rendered hyper- or hypothyroid by administration of l-thyroxine or methimazole for 4 weeks. Among the old rats, the lipid peroxide (LPO) concentrations, measured as thiobarbituric acid (TBA) reactants, were significantly greater in the hyperthyroid than in the euthyroid state and the LPO concentrations measured as TBA+Fe(3+) reactants, which may be precursors of LPO, were significantly greater in the hyperthyroid state, whereas in young rats, the LPO concentrations measured by TBA or TBA+Fe(3+) methods did not differ significantly in the hyperthyroid state. In the euthyroid state, the concentration of LPO measured as TBA+Fe(3+) reactants was significantly reduced with age. Xanthine oxidase (XOD) activity also was markedly increased with age, being more pronounced in the hyperthyroid than in the euthyroid state. The Mn and Cu/Zn superoxide dismutase activities were greater in the hyperthyroid than in the euthyroid state. Glutathione peroxidase activity decreased with age in the euthyroid and, particularly, in the hyperthyroid state. Catalase activity was not affected in the old rats. Concentrations of alpha-tocopherol in the old rats were high in the hyperthyroid state and low in the hypothyroid state, whereas the levels of beta- and gamma-tocopherols in these rats were unchanged in both conditions as compared with the euthyroid state findings. Data suggest that the site of free radical generation differs in older rats, with additional shifts in the location of intracellular lipid peroxidation being noted during hyperthyroidism. Thus, as rats age, the reduction of the free radical scavenger system and the increase in LPO and XOD activities might induce myocardial dysfunction.

Aging↗
PubMed2000

[An unusual case of epilepsy exhibiting gelastic seizure, simple visual hallucination, and transient swelling of the left parieto-occipital region].

We report a 74-year-old man with gelastic seizure, simple visual hallucination, and adversive seizure. The patient described his visual hallucinations as "rotating light like a firefly" and "mimicking a stream". Brain CT scan showed a transient swelling as well as low density of a left parieto-occipital region. Electroencephalographic study revealed spikes and fast waves beginning at left occipital region. Although temporal lobe and hypothalamic lesions (especially hypothalamic hamartomas) are well known as origins of gelastic seizures, we could not find any report that described a series of occurrence of gelastic seizure and simple visual hallucination. Usually, simple visual hallucination is thought to occur in occipital lesion. In our case, it is possible that gelastic seizure and simple visual hallucination are related to the epileptic discharge from occipital lesion directly or indirectly. The reversible brain swelling with low density seen in the present case might be caused by cytotoxic edema due to status epilepticus.

Aged↗
PubMed2000

[Rating scale and functional prognosis of Parkinson's disease].

Parkinson's disease is a progressive neurodegenerative disorder. Motor functions of patients with Parkinson's disease are determined by its cardinal symptoms: akinesia, tremor, rigidity and disturbed righting reflexes. To evaluate degree of disability and rate of its progression in Parkinson disease, simple but reliable and reproducible rating scales are essential. Those that essentially fulfil such conditions are Hoehn and Yahr Scale, Schwab and England Scale, and Unified Parkinson's Disease Rating Scale (UPDRS). Levodopa, the major anti-parkinsonian agent, has greatly improved the motor functions of the Parkinson's disease patients and prolonged their life expectancy. Studies using the above mentioned scales compared the rate of disability progression and the motor functional prognosis between pre- and post-levodopa era, and always demonstrated the levodopa's benefits for the prognosis. Side effects of long administration of levodopa such as motor fluctuation, dyskinesia, wearing-off or on-off phenomenon, and psychosis, however, are disability factors to the patients' motor functions. Rating scales that can integrate the side effects to evaluate the functions will be required.

Disability Evaluation↗
PubMed2000

Incorporation and differentiation of hippocampus-derived neural stem cells transplanted in injured adult rat retina.

PURPOSE: In a previous study it has been shown that adult rat hippocampus-derived neural stem cells can be successfully transplanted into neonatal retinas, where they differentiate into neurons and glia, but they cannot be transplanted into adult retinas. In the current study, the effect of mechanical injury to the adult retina on the survival and differentiation of the grafted hippocampal stem cells was determined. METHODS: Mechanical injury was induced in the adult rat retina by a hooked needle. A cell suspension (containing 90,000 neural stem cells) was slowly injected into the vitreous space. The specimens were processed for immunohistochemical studies at 1, 2, and 4 weeks after the transplantation. RESULTS: In the best case, incorporation of grafted stem cells was seen in 50% of the injured retinas. Most of these cells located from the ganglion cell layer through the inner nuclear layer close to the injury site. Immunohistochemically, at 1 week, more than half of the grafted cells expressed nestin. At 4 weeks, some grafted cells showed immunoreactivity for microtubule-associated protein (MAP) 2ab, MAP5, and glial fibrillary acidic protein (GFAP), suggesting progress in differentiation into cells of neuronal and astroglial lineages. However, they showed no immunoreactivity for HPC-1, calbindin, and rhodopsin, which suggests that they did not differentiate into mature retinal neurons. Immunoelectron microscopy revealed the formation of synapse-like structures between graft and host cells. CONCLUSIONS: By the manipulation of mechanical injury, the incorporation and subsequent differentiation of the grafted stem cells into neuronal and glial lineage, including the formation of synapse-like structures, can be achieved, even in the adult rat retina.

Animals↗
PubMed2000

[Intracranial inhibitory mechanisms in clinically diagnosed corticobasal degeneration: a study of a silent period followed by transcranial magnetic stimulation].

A 52-year-old man with clinically diagnosed corticobasal degeneration (CBD) who developed the asymmetric akinetic-rigid syndrome was studied by means of transcranial magnetic stimulation (TMS) after an interval of two years. TMS of the motor cortex during tonic muscle contraction causes a silent period immediately after a motor evoked potential in an electromyogram. This silent period is considered to reflect activity of an intracortical inhibitory mechanism. In this patient, the motor symptoms started from the left half of the body and spread to the right. The major neurological findings were dystonia, rigidity, clumsiness, and hyperreflexia. The involuntary contraction of the muscles, which was unrelated to voluntary movement, seemed to be responsible for his signs and symptoms. There was laterality of the threshold intensity and the duration of the silent period after a motor evoked potential; the threshold was higher and the duration was shorter on the affected side. Also, we found that the threshold increased and the duration decreased as his motor dysfunction progressed, which has not been reported before. A comparison of the clinical symptoms and the results of TMS in this case together with previous TMS data on CBD suggests that a disorder of the intracortical inhibitory mechanism is closely related to the movement impairment in CBD.

Basal Ganglia Diseases↗
PubMed2000

[A case report of chronic myelocytic leukemia with multiple brain metastases, which responded to the gamma-knife therapy].

We report a 78-year-old woman who had multiple leukemic cell tumors in the brain in the course of chronic myelocytic leukemia (CML). As far as we could survey, such brain tumors were extremely rare. She had been followed because of chronic phase of CML until October, 1998, when she noticed muscle weakness in her left upper and lower extremity. A head MRI revealed multiple masses in the brain, a biopsy of which revealed a tumor of CML cells. Although 40 Gy gamma-knife therapy had reduced the size and numbers of brain tumors, we found recurrence of left hemiparesis and tumors three months after the gamma-knife therapy. Whole brain irradiation therapy (total 30 Gy) was somewhat effective to the tumor and hemiparesis transiently subsided. Thereafter her general condition worsened again, and she died in June, 1999, eight months after the diagnosis of the brain tumors of leukemic cells. We had not seen any other clinical evidence of generalized blastic crisis in this patient. In our case, MRI of the brain showed two patterns of metastases, tumor forming and cortical invasive type. We thought that these two patterns of brain involvement might show different responses to the radiation therapy, and it was characteristic in this patient.

Aged↗
PubMed1999

Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage.

BACKGROUND: Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected. OBJECTIVE: To search for new anatomic substrates for focal retrograde amnesia. METHODS: We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis. RESULTS: Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests. CONCLUSIONS: A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

Adult↗
PubMed1999

A case of McLeod syndrome with unusually severe myopathy.

A 51-year-old man developed weakness and muscle atrophy in the legs at the age of 41, later followed by choreiform involuntary movements. Neurological and laboratory examinations revealed severe muscle weakness and atrophy, and areflexia in all the extremities, acanthocytosis and an elevated serum creatine kinase level. Together with these findings, the weak expression of Kell blood group antigens and the absence of the Kx antigen led to a definite diagnosis of McLeod syndrome for his condition. Brain magnetic resonance imaging revealed marked atrophy of the head of the caudate nuclei. Although immunocytochemical analysis of dystrophin in muscle specimens from our patient revealed normal staining, we found prominent fiber size variability, central nuclei, and connective tissue proliferation as well as necrotic and regenerating fibers, which are as a whole compatible with the myopathology of muscular dystrophy. Moreover, muscle computerized tomography of the lower extremities revealed the 'selectivity pattern' characteristically reported in muscular dystrophies including Duchenne type muscular dystrophy. The muscular symptoms and pathology in McLeod syndrome have been reported to be mild, but the present case clearly shows that the muscular features in this condition may be much more severe than previously thought.

Acanthocytes↗