Glial cell line-derived neurotrophic factor (GDNF) therapy for Parkinson's disease.

Many studies using animals clarify that glial cell line-derived neurotrophic factor (GDNF) has strong neuroprotective and neurorestorative effects on dopaminergic neurons. Several pilot studies clarified the validity of continuous intraputaminal GDNF infusion to patients with Parkinson's disease (PD), although a randomized controlled trial of GDNF therapy published in 2006 resulted in negative outcomes, and controversy remains about the efficacy and safety of the treatment. For a decade, our laboratory has investigated the efficacy and the most appropriate method of GDNF administration using animals, and consequently we have obtained some solid data that correspond to the results of clinical trials. In this review, we present an outline of our studies and other key studies related to GDNF, the current state of the research, problems to be overcome, and predictions regarding the use of GDNF therapy for PD in the future.</p

Targeting Neurogenesis in Seeking Novel Treatments for Ischemic Stroke

The interruption of cerebral blood flow leads to ischemic cell death and results in ischemic stroke. Although ischemic stroke is one of the most important causes of long-term disability and mortality, limited treatments are available for functional recovery. Therefore, extensive research has been conducted to identify novel treatments. Neurogenesis is regarded as a fundamental mechanism of neural plasticity. Therefore, therapeutic strategies targeting neurogenesis are thought to be promising. Basic research has found that therapeutic intervention including cell therapy, rehabilitation, and pharmacotherapy increased neurogenesis and was accompanied by functional recovery after ischemic stroke. In this review, we consolidated the current knowledge of the relationship between neurogenesis and treatment for ischemic stroke. It revealed that many treatments for ischemic stroke, including clinical and preclinical ones, have enhanced brain repair and functional recovery post-stroke along with neurogenesis. However, the intricate mechanisms of neurogenesis and its impact on stroke recovery remain areas of extensive research, with numerous factors and pathways involved. Understanding neurogenesis will lead to more effective stroke treatments, benefiting not only stroke patients but also those with other neurological disorders. Further research is essential to bridge the gap between preclinical discoveries and clinical implementation

Automatic sensing device of electrical characteristics of living trees

The electrical impedance of a living tissue reflects its cell construction and physiological activity. For this purpose we developed an automatic sensing device of electrical tissue characteristics. The system is composed of a part measuring impedance at multifrequency points and a part analyzing parameters of dispersion of bioelectrical impedance, impedances are measured at eight frequency points of 1 kHz-500 kHz. The parameters for Cole-Cole arc's law are determined automatically by a personal computer program </p

Animal Models for Parkinson's Disease Research: Trends in the 2000s

Parkinson's disease (PD) is a chronic and progressive movement disorder and the second most common neurodegenerative disease. Although many studies have been conducted, there is an unmet clinical need to develop new treatments because, currently, only symptomatic therapies are available. To achieve this goal, clarification of the pathology is required. Attempts have been made to emulate human PD and various animal models have been developed over the decades. Neurotoxin models have been commonly used for PD research. Recently, advances in transgenic technology have enabled the development of genetic models that help to identify new approaches in PD research. However, PD animal model trends have not been investigated. Revealing the trends for PD research will be valuable for increasing our understanding of the positive and negative aspects of each model. In this article, we clarified the trends for animal models that were used to research PD in the 2000s, and we discussed each model based on these trends

A Rare Case of Idiopathic Spinal Cord Herniation Treated by DuraGen® Collagen Matrix Graft

We report a rare case of idiopathic spinal cord herniation (ISCH) with a history of cerebrospinal fluid (CSF) leakage. ISCH is a protrusion of the spinal cord through a dural defect. Thin constructive interference in steady-state (CISS) images clearly demonstrated the herniated cord in the present case. The myelopathy worsened and the patient underwent surgery for reduction of herniated spinal cord; the dural defect was filled by placing collagen matrix graft (DuraGen®) between the inner and outer dural layers. The patient’s symptoms have improved without relapse for 8 months since surgery. This method may be a good surgical option for cases of spinal cord herniation

Chiari Malformation with Thick Occipital Bone

A case of a Chiari malformation with an extraordinarily thick occipital bone is described. The thick occipital bone might make the posterior fossa narrow with consequent herniation of the cerebellar tonsils to the foramen magnum and formation of a syrinx. At dural plasty, well-developed marginal and occipital sinuses should be deliberately handled with the preservation of normal venous drainage. This case gives us the essence of the occurrence mechanisms of Chiari malformation and foramen magnum decompression

Mesenchymal Stem Cell Therapy for Ischemic Stroke

　To date, many animal studies have indicated the neuroprotective effects of mesenchymal stem cell (MSC) transplantation in ischemic stroke. Several clinical studies have also revealed the safety, feasibility, and neuroprotective effects in ischemic stroke patients. In this review, we present the main approaches of MSC transplantation in ischemic stroke, the mechanisms of MSC therapy, and the current clinical studies on MSC transplantation in ischemic stroke patients. We also explore the safety of MSC transplantation and conclude that MSC therapy will play an important role in the future treatment of ischemic stroke. The optimal timing, approach, and cell dose in the transplantation are important issues for successful clinical application

Precise MEP monitoring with a reduced interval is safe and useful for detecting permissive duration for temporary clipping

Although temporary clipping of the parent artery is an indispensable technique in clipping surgery for intracranial aneurysms, the permissive duration of temporary clipping is still not well known. The aim of this study is to confirm the safety of precise motor evoked potential (MEP) monitoring and to estimate the permissive duration of temporary clipping for middle cerebral artery (MCA) aneurysm based on precise MEP monitoring results. Under precise MEP monitoring via direct cortical stimulation every 30 seconds to 1 minute, surgeons released a temporary clip and waited for MEP amplitude to recover following severe (>50%) reduction of MEP amplitude during temporary clipping. Precise MEP monitoring was safely performed. Twenty-eight instances of temporary clipping were performed in 42 MCA aneurysm clipping surgeries. Because precise MEP monitoring could be used to determine when to release a temporary clip even with a severe reduction in MEP amplitude due to lengthy temporary clipping, no patients experienced permanent postoperative hemiparesis. Based on logistic regression analysis, if a temporary clip is applied for 312 seconds or more, there is a higher probability of a severe reduction in MEP amplitude. We should therefore release temporary clips after 5 minutes in order to avoid permanent postoperative hemiparesis