Kenkichi Nozaki
Medical University of South Carolina
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Featured researches published by Kenkichi Nozaki.
Presse Medicale | 2012
Kenkichi Nozaki; Marc A. Judson
Sarcoidosis is an idiopathic granulomatous disease affecting multiple organs. Neurosarcoidosis, involving the central and/or peripheral nervous systems, is a relatively rare form of sarcoidosis. Its clinical manifestations include cranial neuropathies, meningitis, neuroendocrinological dysfunction, hydrocephalus, seizures, neuropsychiatric symptoms, myelopathy and neuropathies. The diagnosis is problematic, especially when occurring as an isolated form without other organ involvement. Distinguishing neurosarcoidosis from other granulomatous diseases and multiple sclerosis is especially important. Although biopsy of neural tissue is the gold standard for the diagnosis of neurosarcoidosis, this is often not practical and the diagnosis must be inferred though other tests, often coupled with biopsy of extraneural organs. Corticosteroids and other immuno-suppressants are frequently used for the treatment of neurosarcoidosis. This article reviews the epidemiology, pathogenesis, pathology, clinical features, diagnosis, diagnostic tests, diagnostic criteria, and therapy of neurosarcoidosis.
The American Journal of the Medical Sciences | 2011
Kenkichi Nozaki; David E. Stickler; Nada Abou-Fayssal; Pierre Giglio; Richard M. Silver; Diane L. Kamen; Rodney S. Daniel; Marc A. Judson
Introduction:Neurological deficits that occur during treatment with tumor necrosis factor (TNF)-&agr; antagonists are rare, and their clinical features have not been fully elucidated. Methods:Retrospective review of medical records of 9 patients who were given TNF-&agr; antagonists, subsequently developed neurological deficits and were cared for at the Medical University of South Carolina between January 2002 and May 2010. Adverse drug reaction probability scale was used for the assessment of their causal connection. Results:The underlying diseases for which TNF-&agr; antagonists were administered included rheumatologic disorders (4), sarcoidosis (3), psoriasis (1) and Crohns disease (1). Etanercept, infliximab or adalimumab was administered to these patients. Neurological complications included central or peripheral demyelination (5), antiphospholipid syndrome/central nervous system lupus (1), Epstein-Barr virus encephalitis (1), axonal sensory polyneuropathy (1) and small fiber polyneuropathy (1). TNF-&agr; antagonists were discontinued in 8 patients and clinical improvement was seen in 3 of them. Additional therapies were given in 4 patients. An adverse drug reaction probability score suggested probable (3/9) and possible (6/9) causal relationships. Conclusions:Neurological deficits that develop during treatment with TNF-&agr; antagonists are relatively rare but important potential complications of these drugs. Determining if the relationship between the neurological deficits and TNF-&agr; antagonist therapy is causal can be challenging and can impact patient care.
The American Journal of the Medical Sciences | 2014
Mimi Sohn; Kenkichi Nozaki; Daniel A. Culver; Marc A. Judson; Thomas F. Scott; Jinny Tavee
Background:Spinal cord neurosarcoidosis (SN) is problematic to diagnose because it mimics other inflammatory neurologic diseases. The authors report the clinical features of 29 SN cases. Methods:They retrospectively reviewed the medical records of 29 histologically proven sarcoidosis patients with spinal cord involvement seen at 3 university medical centers. They collected clinical data including laboratory and radiological findings. Clinical outcomes were assessed retrospectively using the modified Rankin scale. Results:The cohort included high number of African Americans (16/29, 55%). The lung and intrathoracic lymph nodes were the most common confirmatory biopsy sites (18/29, 62%), whereas the spinal cord was a relatively uncommon one (4/29, 14%). The most common presenting symptoms were lower extremity weakness and paresthesias. Thoracic segment was most frequently involved (21/27, 78%). Lesions were mostly intramedullary (22/27, 81%), although nearly half involved the leptomeninges (13/27, 48%). The average size of a lesion spanned 3.9 spine segments (range, 1–9); 17 of 22 (77%) intramedullary patients had ≥3 spine segments involved. Angiotensin-converting enzyme levels in cerebrospinal fluid were elevated in only 2 of 11 (18%) patients. All patients received glucocorticosteroids. Additional immune-modulating agents were used in 24 of 29 (83%) patients. Scores on the modified Rankin scale at the final follow-up visit were improved. Conclusions:Most SN cases were diagnosed indirectly based on extraneural tissue biopsy. Extended spinal cord lesion (≥3 spine segments) may be useful to distinguish SN from multiple sclerosis. Cerebrospinal fluid analysis was of limited value. Most patients experienced clinical improvement with immunosuppressive treatment, but many required combination therapy.
The Neurologist | 2012
Kenkichi Nozaki; Thomas F. Scott; Mimi Sohn; Marc A. Judson
Background:Neurosarcoidosis occurs in the central or peripheral nervous system and is usually associated with other sarcoidosis organ involvement. However, when sarcoidosis develops exclusively in the nervous system, its diagnosis is problematic. Methods:Retrospective analysis of patients who were histologically diagnosed with neurosarcoidosis without other organ involvement (isolated neurosarcoidosis) at Medical University of South Carolina and Allegheny General Hospital. For comparison, we also collected data from neurosarcoidosis patients with histologic evidence in an extraneural organ (systemic neurosarcoidosis). Results:Ninety-one cases of neurosarcoidosis were identified with 10 patients having isolated neurosarcoidosis. Common clinical manifestations of the isolated neurosarcoidosis patients were headache (9), paresthesia (5), and cranial neuropathies (4). All isolated neurosarcoidosis patients underwent a biopsy from the central nervous system. The prebiopsy impression included lymphoma (4), tumor (2), and sarcoidosis (2). In all patients, no extranueral sarcoidosis developed during a relatively long follow-up period (mean 58 mo). Compared with the systemic neurosarcoidosis cohort (60), isolated neurosarcoidosis patients had similar demographics and neurological manifestations with a few exceptions including a more common frequency of headache, hemiparesis, and radiculopathy, leptomeningeal involvement on brain MRI, increased cell count in cerebrospinal fluid, and a more favorable clinical outcome (P<0.05). The duration of follow-up and the number of studies performed to evaluate patients for extraneural sarcoidosis were similar in the 2 cohorts. Conclusions:The clinical and radiologic features of isolated neurosarcoidosis are similar to those of systemic neurosarcoidosis with a few exceptions. The diagnosis of isolated neurosarcoidosis is problematic and often not considered before biopsy of neural tissue.
Journal of the Neurological Sciences | 2010
Kenkichi Nozaki; Nada Abou-Fayssal
Marburg variant multiple sclerosis (MS) is an acute, fulminant and monophasic variant of MS that usually leads to death within weeks to months. No consistently successful treatment is known. We describe a 26-year-old woman who developed acute and progressive motor and sensory deficits. Demyelinating disease was suspected based on brain and spinal MRI and cerebrospinal fluid results. Multiple treatments including corticosteroids, plasma exchange and intravenous immunoglobulin could not halt her clinical and radiological deterioration. She became near quadriplegic and developed motor aphasia. A diagnosis of Marburg variant MS was considered and she was given high dose cyclophosphamide (HiCy) at 50mg/kg/day for four consecutive days, followed by granulocyte colony-stimulating factor six days after the completion of the cyclophosphamide treatment. HiCy successfully induced neutropenia. She started to show a steady neurological improvement from day 17 of HiCy treatment. MR studies two months after HiCy treatment showed significant decrease in the size and enhancement of the lesions. Five months later she had minimal residual right-sided weakness and was able to ambulate without assistance. The great outcome seen in our case suggests that HiCy should be considered as a potential treatment for patients with Marburg variant MS who fail to respond to standard therapy.
Journal of Neuroscience Research | 2011
Kenkichi Nozaki; Arabinda Das; Swapan K. Ray; Naren L. Banik
In idiopathic inflammatory myopathies (IIMs), extracellular inflammatory stimulation is considered to induce secondary intracellular inflammatory changes including expression of major histocompatibility complex class‐I (MHC‐I) and to produce a self‐sustaining loop of inflammation. We hypothesize that activation of calpain, a Ca2+‐sensitive protease, bridges between these extracellular inflammatory stress and intracellular secondary inflammatory changes in muscle cells. In this study, we demonstrated that treatment of rat L6 myoblast cells with interferon‐γ (IFN‐γ) caused expression of MHC‐I and inflammation‐related transcription factors (phosphorylated‐extracellular signal‐regulated kinase 1/2 and nuclear factor‐κB). We also demonstrated that treatment with tumor necrosis factor‐α (TNF‐α) induced apoptotic changes and activation of calpain and cyclooxygenase‐2. Furthermore, we found that posttreatment with calpeptin attenuated the intracellular changes induced by IFN‐γ or TNF‐α. Our results indicate that calpain inhibition attenuates apoptosis and secondary inflammatory changes induced by extracellular inflammatory stimulation in the muscle cells. These results suggest calpain as a potential therapeutic target for treatment of IIMs.
Experimental Neurology | 2010
Kenkichi Nozaki; Arabinda Das; Swapan K. Ray; Naren L. Banik
Idiopathic inflammatory myopathies (IIMs), comprising of polymyositis, dermatomyositis, and inclusion-body myositis, are characterized by muscle weakness and various types of inflammatory changes in muscle cells. They also show non-inflammatory changes, including perifascicular atrophy, mitochondrial changes, and amyloid protein accumulation. It is possible that some molecules/mechanisms bridge the extracellular inflammatory stimulation and intracellular non-inflammatory changes. One such mechanism, Ca(2+) influx leading to calpain activation has been proposed. In this study, we demonstrated that post-treatment with calpeptin (calpain inhibitor) attenuated intracellular changes to prevent apoptosis (Wright staining) through both mitochondrial pathway (increase in Bax:Bcl-2 ratio) and endoplasmic reticulum stress pathway (activation of caspase-12), which were induced by interferon-gamma (IFN-γ) stimulation in rat L6 myoblast cells. Our results also showed that calpeptin treatment inhibited the expression of calpain, aspartyl protease cathepsin D, and amyloid precursor protein. Thus, our results indicate that calpain inhibition plays a pivotal role in attenuating muscle cell damage from inflammatory stimulation due to IFN-γ, and this may suggest calpain as a possible therapeutic target in IIMs.
Journal of Neuroscience Research | 2012
Sookyoung Park; Kenkichi Nozaki; M. Kelly Guyton; Joshua A. Smith; Swapan K. Ray; Naren L. Banik
Muscle weakness and atrophy are important manifestations of multiple sclerosis (MS). To investigate the pathophysiological mechanisms of skeletal muscle change in MS, we induced experimental autoimmune encephalomyelitis (EAE) in Lewis male rats and examined morphological and molecular changes in skeletal muscle. We also treated EAE rats with calpepetin, a calpain inhibitor, to examine its beneficial effects on skeletal muscle damage. Morphological changes in muscle tissue of EAE rats included smaller and irregularly shaped muscle fibers and fibrosis. Western blot analysis demonstrated increased calpain:calpastatin ratio, inflammation‐related transcription factors (nuclear factor‐κB:inhibitor of κB α ratio), and proinflammatory enzymes (cyclooxygenase‐2). TUNEL‐positive myonuclei in skeletal muscle cells of EAE rats indicated cell death. In addition, markers of apoptotic cell death (Bax:Bcl‐2 ratio and caspase‐12 protein levels) were elevated. Expression of muscle‐specific ubiquitin ligases (muscle atrophy F‐box and muscle ring finger protein 1), was upregulated in muscle tissue of EAE‐vehicle animals. Both prophylactic and therapeutic treatment with calpeptin partially attenuated muscle changes noted in EAE animals. These results indicate that morphological and molecular changes including apoptotic cell death and protein breakdown develop in skeletal muscle of EAE animals and that these changes can be reversed by calpain inhibition.
Journal of Neurochemistry | 2014
Sookyoung Park; Kenkichi Nozaki; Joshua A. Smith; James S. Krause; Naren L. Banik
Insulin‐like growth factor‐1 (IGF‐1) is a neuroprotective growth factor that promotes neuronal survival by inhibition of apoptosis. To examine whether IGF‐1 exerts cytoprotective effects against extracellular inflammatory stimulation, ventral spinal cord 4.1 (VSC4.1) motoneuron cells were treated with interferon‐gamma (IFN‐γ). Our data demonstrated apoptotic changes, increased calpain:calpastatin and Bax:Bcl‐2 ratios, and expression of apoptosis‐related proteases (caspase‐3 and ‐12) in motoneurons rendered by IFN‐γ in a dose‐dependent manner. Post‐treatment with IGF‐1 attenuated these changes. In addition, IGF‐1 treatment of motoneurons exposed to IFN‐γ decreased expression of inflammatory markers (cyclooxygenase‐2 and nuclear factor‐kappa B:inhibitor of kappa B ratio). Furthermore, IGF‐1 attenuated the loss of expression of IGF‐1 receptors (IGF‐1Rα and IGF‐1Rβ) and estrogen receptors (ERα and ERβ) induced by IFN‐γ. To determine whether the protective effects of IGF‐1 are associated with ERs, ERs antagonist ICI and selective siRNA targeted against ERα and ERβ were used in VSC4.1 motoneurons. Distinctive morphological changes were observed following siRNA knockdown of ERα and ERβ. In particular, apoptotic cell death assessed by TUNEL assay was enhanced in both ERα and ERβ‐silenced VSC4.1 motoneurons following IFN‐γ and IGF‐1 exposure. These results suggest that IGF‐1 protects motoneurons from inflammatory insult by a mechanism involving pivotal interactions with ERα and ERβ.
Sarcoidosis Vasculitis and Diffuse Lung Diseases | 2014
Marc A. Judson; U. Costabel; M. Drent; A. Wells; L. Maier; L. Koth; H. Shigemitsu; D. A. Culver; Jeffrey M. Gelfand; D. Valeyre; N. Sweiss; Elliot D. Crouser; A. S. Morgenthau; E. E. Lower; Arata Azuma; M. Ishihara; S. Morimoto; T. Yamaguchi; N. Shijubo; J. C. Grutters; M. Rosenbach; Huiping Li; Paola Rottoli; Yoshikazu Inoue; Antje Prasse; R. P. Baughman; Robert P. Baughman; Norman Soskel; Athol U. Wells; Elliott Crouser