Takakazu Oka
Biographic Data
| ID | 8873242 |
|---|---|
| NAME | Takakazu Oka |
| GIVEN NAMES | Takakazu |
| FAMILY NAME | Oka |
| SIGNATURE | OKA T |
| AFFILIATIONS | Kyushu University |
| VERIFIED | No |
| TOTAL WORKS | 28 |
| TOTAL CITATIONS | 0 |
| AUTHOR COUNT | 28 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2001 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 0 |
Post-Covid-19 ME/CFS
Effects of recumbent isometric yoga on the daily functioning level of patients with myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Although seated isometric yoga has been shown to reduce the fatigue and pain of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), some patients who are for the most part bedridden have difficulty practicing it. Many patients with this disease also suffer from fibromyalgia (FM). We developed a recumbent isometric yoga program for patients who were for the most part bedridden, including patients with comorbid FM…
Effects of recumbent isometric yoga on the orthostatic cardiovascular response of patients with myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Our previous studies demonstrated that the regular practice of recumbent isometric yoga reduced the fatigue of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Some patients with ME/CFS have postural orthostatic tachycardia syndrome (POTS); however, the effects of recumbent isometric yoga on orthostatic cardiovascular responses and whether recumbent isometric yoga improves POTS remain unknown. This pilot stud…
Disabling symptoms associated with increased axillary temperature in patients with functional hyperthermia
BACKGROUND: I previously reported a case of functional hyperthermia (FH) in a patient with an axillary temperature just slightly above 37.0 °C who persistently requested treatment. Because the severity of her fatigue increased remarkably when her axillary temperature increased above 37.0 °C, she felt that the temperature of 37.0 °C was disabling. In the present study, I analyzed a larger number of patients with FH to investigate the incidence of …
A patient who recovered from post-Covid myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Some patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) complain of persistent fatigue, dyspnea, pain, and cognitive dysfunction. These symptoms are often described as "long COVID". Whether a patient with long COVID might develop myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is of interest, as is the treatment and management of ME/CFS in a post-COVID patient. Here I report a patient, …
Functional hyperthermia and comorbid psychiatric disorders
Clinical effects of wasabi extract containing 6-MSITC on myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Wasabi (Eutrema japonicum) is a common pungent spice used in Japan. 6-Methylsulfinylhexyl isothiocyanate (6-MSITC) found in the rhizome of wasabi has been shown to have anti-inflammatory and antioxidant effects, as well as improve neuroinflammation and memory. Therefore, we hypothesized that these effects would be beneficial for treating myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The present study was conducted to in…
Effects of practicing yoga on alexisomia
BACKGROUND: Alexisomia refers to difficulties in the awareness and expression of somatic feelings. This idea was proposed by Dr. Yujiro Ikemi as a characteristic observed in patients with psychosomatic diseases and is based on his observations that patients with psychosomatic diseases have difficulty in the awareness and expression of not only their emotions, i.e., alexithymia, but also somatic feelings and sensations, i.e., alexisomia. He also p…
Health-related benefits and adverse events associated with yoga classes among participants that are healthy, in poor health, or with chronic diseases
BACKGROUND: Our previous study demonstrated that 42% of yoga class participants in Japan had chronic diseases requiring medication. This raises the question as to whether those with chronic diseases would benefit from practicing yoga or if they are at higher risk for specific adverse events compared to healthy individuals receiving the same instruction. METHODS: To address these questions, 328 adults who started practicing yoga for the first time…
Shitsu-taikan-sho (alexisomia)
“Shitsu-taikan-sho” is a clinical concept that refers to characteristics of having difficulty in the awareness and expression of somatic feelings or sensations. This concept was first proposed in 1979 by Dr. Yujiro Ikemi, the founder of psychosomatic medicine in Japan, as a characteristic observed in patients with psychosomatic diseases, i.e. physical diseases in which psychosocial factors are closely involved in their onset and progress. Soon af…
Changes in circulating microRNA after recumbent isometric yoga practice by patients with myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Yoga is a representative mind-body therapy. Our previous studies have demonstrated that isometric yoga (i.e. yoga programs that we developed so individuals can practice yoga poses with a self-adjustable isometric load) reduces the fatigue of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS); however, the underlying mechanisms remain unclear. Several studies have suggested that the micro-ribonucleic acid (miRNA)…
The longitudinal effects of seated isometric yoga on blood biomarkers, autonomic functions, and psychological parameters of patients with chronic fatigue syndrome
Background In a previous randomized controlled trial, we found that practicing seated isometric yoga regularly for 2 months improved the fatigue of patients with chronic fatigue syndrome (CFS) who are resistant to conventional therapy. The aim of this pilot study was to investigate the possible mechanisms behind this finding by comparing blood biomarkers, autonomic nervous function, and psychological indices before versus after an intervention pe…
Changes in fatigue, autonomic functions, and blood biomarkers due to sitting isometric yoga in patients with chronic fatigue syndrome
BACKGROUND: In a previous randomized controlled trial, we found that sitting isometric yoga improves fatigue in patients with chronic fatigue syndrome (CFS) who are resistant to conventional therapy. The aim of this study was to investigate possible mechanisms behind this finding, focusing on the short-term fatigue-relieving effect, by comparing autonomic nervous function and blood biomarkers before and after a session of isometric yoga. METHODS:…
Development of a recumbent isometric yoga program for patients with severe chronic fatigue syndrome/myalgic encephalomyelitis
BACKGROUND: Our previous randomized controlled trial demonstrated that isometric yoga in a sitting position reduces fatigue in patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). However, some patients experience difficulties sitting or practicing isometric yoga in a sitting position for long periods. To date, therapeutic interventions for patients with severe symptoms have not been established. Therefore, we developed a re…
A large-scale survey of adverse events experienced in yoga classes
BACKGROUND: Yoga is a representative mind-body therapy of complementary and alternative medicine. In Japan, yoga is practiced widely to promote health, but yoga-associated adverse events have also been reported. To date, the frequencies and characteristics of yoga-related adverse events have not been elucidated. This study was conducted to elucidate the frequencies and characteristics of adverse events of yoga performed in classes and the risk fa…
Effect of 12 weeks of yoga training on the somatization, psychological symptoms, and stress-related biomarkers of healthy women
BACKGROUND: Previous studies have shown that the practice of yoga reduces perceived stress and negative feelings and that it improves psychological symptoms. Our previous study also suggested that long-term yoga training improves stress-related psychological symptoms such as anxiety and anger. However, little is known about the beneficial effects of yoga practice on somatization, the most common stress-related physical symptoms, and stress-relate…
Isometric yoga improves the fatigue and pain of patients with chronic fatigue syndrome who are resistant to conventional therapy
Patients with chronic fatigue syndrome (CFS) often complain of persistent fatigue even after conventional therapies such as pharmacotherapy, cognitive behavioral therapy, or graded exercise therapy. The aim of this study was to investigate in a randomized, controlled trial the feasibility and efficacy of isometric yoga in patients with CFS who are resistant to conventional treatments. This trial enrolled 30 patients with CFS who did not have sati…
Isometric yoga improves the fatigue and pain of patients with chronic fatigue syndrome who are resistant to conventional therapy
BACKGROUND: Patients with chronic fatigue syndrome (CFS) often complain of persistent fatigue even after conventional therapies such as pharmacotherapy, cognitive behavioral therapy, or graded exercise therapy. The aim of this study was to investigate in a randomized, controlled trial the feasibility and efficacy of isometric yoga in patients with CFS who are resistant to conventional treatments. METHODS: This trial enrolled 30 patients with CFS …
Effects of Kampo on functional gastrointestinal disorders
This article reviews the effectiveness of Kampo (traditional Japanese herbal medicine) in the treatment of functional gastrointestinal disorders, especially functional dyspepsia (FD) and irritable bowel syndrome (IBS). The results of four randomized, controlled trials (RCTs) suggested the usefulness of rikkunshito in relieving the subjective symptoms of patients with FD. Rikkunshito significantly improved not only gastric symptoms, such as epigas…
Psychological stress contributed to the development of low-grade fever in a patient with chronic fatigue syndrome
BACKGROUND: Low-grade fever is a common symptom in patients with chronic fatigue syndrome (CFS), but the mechanisms responsible for its development are poorly understood. We submit this case report that suggests that psychological stress contributes to low-grade fever in CFS. CASE PRESENTATION: A 26-year-old female nurse with CFS was admitted to our hospital. She had been recording her axillary temperature regularly and found that it was especial…
Age distribution and gender differences in psychogenic fever patients
Psychogenic fever is one of the most common psychosomatic diseases. In Japan, psychogenic fever has generally been reported to occur in adolescents, with a peak seen at age 13. However, in our department we have encountered many adults with psychogenic fever. Therefore, we investigated all outpatients who visited the Psychosomatic Department of the University of Occupational and Environmental Health between April 2003 and March 2007. Of the 2705 …
Pyrogenic Cytokines Did Not Mediate a Stress Interview-Induced Hyperthermic Response in a Patient With Psychogenic Fever
OBJECTIVE: To investigate if pyrogenic cytokines mediated psychological stress-induced hyperthermic response in a patient with psychogenic fever. Despite many case reports on psychogenic fever, the mechanism responsible for how psychological stress increases core body temperature (Tc) in humans is not yet known. CASE PRESENTATION: A 13-year-old girl with fever (>38 degrees C) of unknown causes was referred to our department because psychogenic fe…
Green odor attenuates a cold pressor test-induced cardiovascular response in healthy adults
BACKGROUND: Green odor, a mixture of equal amounts of 2E-hexenal (leaf aldehyde) and 3Z-hexenol (leaf alcohol) has been demonstrated to have an anti-stress effect in rats. This study investigated whether or not green odor also has an anti-stress effect in humans. METHODS: Changes in blood pressure, heart rate, and the skin temperature of a fingertip were observed after presenting green odor at a concentration of 0.03% or vehicle via inhalation th…
Psychological and weight-related characteristics of patients with anorexia nervosa-restricting type who later develop bulimia nervosa
BACKGROUND: Patients with anorexia nervosa-restricting type (AN-R) sometimes develop accompanying bulimic symptoms or the full syndrome of bulimia nervosa (BN). If clinicians could predict who might change into the bulimic sub-type or BN, preventative steps could be taken. Therefore, we investigated anthropometric and psychological factors possibly associated with such changes. METHOD: All participants were from a study by the Japanese Genetic Re…
Cilnidipine lowered psychological stress-induced increase in blood pressure in a hypertensive man
BACKGROUND: In some hypertensive patients, psychological stress makes blood pressure difficult to control and causes physical symptoms such as headache or dizziness. We report the case of a hypertensive man whose psychological stress-induced increase in blood pressure was attenuated by cilnidipine. CASE PRESENTATION: The patient (a 72-year-old man) had hypertension and was on antihypertensive therapy. When mentally concentrating, he experienced o…
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Mechanisms and Mediators of Psychological Stress-Induced Rise in Core Temperature
OBJECTIVE: Despite numerous case reports on "psychogenic fever," it remains uncertain how psychological stress raises core temperature and whether the rise in core temperature is a real fever or a hyperthermia. This article reviews studies on the psychological stress-induced rise in core temperature (PSRCT) in animals with the aim to facilitate studies on the mechanisms of so-called psychogenic fever in humans. METHODS: To address this question, …
Cilnidipine lowered psychological stress-induced increase in blood pressure in a hypertensive man
BACKGROUND: In some hypertensive patients, psychological stress makes blood pressure difficult to control and causes physical symptoms such as headache or dizziness. We report the case of a hypertensive man whose psychological stress-induced increase in blood pressure was attenuated by cilnidipine. CASE PRESENTATION: The patient (a 72-year-old man) had hypertension and was on antihypertensive therapy. When mentally concentrating, he experienced o…
Age and gender differences of psychogenic fever
BACKGROUND: Psychogenic fever is one of the most common psychosomatic diseases. Patients with psychogenic fever have acute or persistent body temperature above normal range in psychologically stressful situations. In spite of numerous case reports on psychogenic fever, there are few epidemiological studies. Therefore, our goal was to investigate the age distribution and gender differences of psychogenic fever in Japan. METHODS: To achieve this go…
Rikkunshi-to attenuates adverse gastrointestinal symptoms induced by fluvoxamine
BACKGROUND: Upper gastrointestinal (GI) symptoms such as nausea and vomiting are common adverse events associated with selective serotonin reuptake inhibitors (SSRIs), and may result in discontinuation of drug therapy in patients with depressive disorder. Rikkunshi-to (formulation TJ-43), a traditional herbal medicine, has been reported to improve upper GI symptoms and comorbid depressive symptoms in patients with functional dyspepsia. The aim of…
Green odor attenuates a cold pressor test-induced cardiovascular response in healthy adults
BACKGROUND: Green odor, a mixture of equal amounts of 2E-hexenal (leaf aldehyde) and 3Z-hexenol (leaf alcohol) has been demonstrated to have an anti-stress effect in rats. This study investigated whether or not green odor also has an anti-stress effect in humans. METHODS: Changes in blood pressure, heart rate, and the skin temperature of a fingertip were observed after presenting green odor at a concentration of 0.03% or vehicle via inhalation th…
Psychological and weight-related characteristics of patients with anorexia nervosa-restricting type who later develop bulimia nervosa
BACKGROUND: Patients with anorexia nervosa-restricting type (AN-R) sometimes develop accompanying bulimic symptoms or the full syndrome of bulimia nervosa (BN). If clinicians could predict who might change into the bulimic sub-type or BN, preventative steps could be taken. Therefore, we investigated anthropometric and psychological factors possibly associated with such changes. METHOD: All participants were from a study by the Japanese Genetic Re…
Age distribution and gender differences in psychogenic fever patients
Psychogenic fever is one of the most common psychosomatic diseases. In Japan, psychogenic fever has generally been reported to occur in adolescents, with a peak seen at age 13. However, in our department we have encountered many adults with psychogenic fever. Therefore, we investigated all outpatients who visited the Psychosomatic Department of the University of Occupational and Environmental Health between April 2003 and March 2007. Of the 2705 …
Pyrogenic Cytokines Did Not Mediate a Stress Interview-Induced Hyperthermic Response in a Patient With Psychogenic Fever
OBJECTIVE: To investigate if pyrogenic cytokines mediated psychological stress-induced hyperthermic response in a patient with psychogenic fever. Despite many case reports on psychogenic fever, the mechanism responsible for how psychological stress increases core body temperature (Tc) in humans is not yet known. CASE PRESENTATION: A 13-year-old girl with fever (>38 degrees C) of unknown causes was referred to our department because psychogenic fe…
Psychological stress contributed to the development of low-grade fever in a patient with chronic fatigue syndrome
BACKGROUND: Low-grade fever is a common symptom in patients with chronic fatigue syndrome (CFS), but the mechanisms responsible for its development are poorly understood. We submit this case report that suggests that psychological stress contributes to low-grade fever in CFS. CASE PRESENTATION: A 26-year-old female nurse with CFS was admitted to our hospital. She had been recording her axillary temperature regularly and found that it was especial…
Effect of 12 weeks of yoga training on the somatization, psychological symptoms, and stress-related biomarkers of healthy women
BACKGROUND: Previous studies have shown that the practice of yoga reduces perceived stress and negative feelings and that it improves psychological symptoms. Our previous study also suggested that long-term yoga training improves stress-related psychological symptoms such as anxiety and anger. However, little is known about the beneficial effects of yoga practice on somatization, the most common stress-related physical symptoms, and stress-relate…
Isometric yoga improves the fatigue and pain of patients with chronic fatigue syndrome who are resistant to conventional therapy
Patients with chronic fatigue syndrome (CFS) often complain of persistent fatigue even after conventional therapies such as pharmacotherapy, cognitive behavioral therapy, or graded exercise therapy. The aim of this study was to investigate in a randomized, controlled trial the feasibility and efficacy of isometric yoga in patients with CFS who are resistant to conventional treatments. This trial enrolled 30 patients with CFS who did not have sati…
Isometric yoga improves the fatigue and pain of patients with chronic fatigue syndrome who are resistant to conventional therapy
BACKGROUND: Patients with chronic fatigue syndrome (CFS) often complain of persistent fatigue even after conventional therapies such as pharmacotherapy, cognitive behavioral therapy, or graded exercise therapy. The aim of this study was to investigate in a randomized, controlled trial the feasibility and efficacy of isometric yoga in patients with CFS who are resistant to conventional treatments. METHODS: This trial enrolled 30 patients with CFS …
Effects of Kampo on functional gastrointestinal disorders
This article reviews the effectiveness of Kampo (traditional Japanese herbal medicine) in the treatment of functional gastrointestinal disorders, especially functional dyspepsia (FD) and irritable bowel syndrome (IBS). The results of four randomized, controlled trials (RCTs) suggested the usefulness of rikkunshito in relieving the subjective symptoms of patients with FD. Rikkunshito significantly improved not only gastric symptoms, such as epigas…
A large-scale survey of adverse events experienced in yoga classes
BACKGROUND: Yoga is a representative mind-body therapy of complementary and alternative medicine. In Japan, yoga is practiced widely to promote health, but yoga-associated adverse events have also been reported. To date, the frequencies and characteristics of yoga-related adverse events have not been elucidated. This study was conducted to elucidate the frequencies and characteristics of adverse events of yoga performed in classes and the risk fa…
Development of a recumbent isometric yoga program for patients with severe chronic fatigue syndrome/myalgic encephalomyelitis
BACKGROUND: Our previous randomized controlled trial demonstrated that isometric yoga in a sitting position reduces fatigue in patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). However, some patients experience difficulties sitting or practicing isometric yoga in a sitting position for long periods. To date, therapeutic interventions for patients with severe symptoms have not been established. Therefore, we developed a re…
Changes in fatigue, autonomic functions, and blood biomarkers due to sitting isometric yoga in patients with chronic fatigue syndrome
BACKGROUND: In a previous randomized controlled trial, we found that sitting isometric yoga improves fatigue in patients with chronic fatigue syndrome (CFS) who are resistant to conventional therapy. The aim of this study was to investigate possible mechanisms behind this finding, focusing on the short-term fatigue-relieving effect, by comparing autonomic nervous function and blood biomarkers before and after a session of isometric yoga. METHODS:…
Changes in circulating microRNA after recumbent isometric yoga practice by patients with myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Yoga is a representative mind-body therapy. Our previous studies have demonstrated that isometric yoga (i.e. yoga programs that we developed so individuals can practice yoga poses with a self-adjustable isometric load) reduces the fatigue of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS); however, the underlying mechanisms remain unclear. Several studies have suggested that the micro-ribonucleic acid (miRNA)…
The longitudinal effects of seated isometric yoga on blood biomarkers, autonomic functions, and psychological parameters of patients with chronic fatigue syndrome
Background In a previous randomized controlled trial, we found that practicing seated isometric yoga regularly for 2 months improved the fatigue of patients with chronic fatigue syndrome (CFS) who are resistant to conventional therapy. The aim of this pilot study was to investigate the possible mechanisms behind this finding by comparing blood biomarkers, autonomic nervous function, and psychological indices before versus after an intervention pe…
Shitsu-taikan-sho (alexisomia)
“Shitsu-taikan-sho” is a clinical concept that refers to characteristics of having difficulty in the awareness and expression of somatic feelings or sensations. This concept was first proposed in 1979 by Dr. Yujiro Ikemi, the founder of psychosomatic medicine in Japan, as a characteristic observed in patients with psychosomatic diseases, i.e. physical diseases in which psychosocial factors are closely involved in their onset and progress. Soon af…
Health-related benefits and adverse events associated with yoga classes among participants that are healthy, in poor health, or with chronic diseases
BACKGROUND: Our previous study demonstrated that 42% of yoga class participants in Japan had chronic diseases requiring medication. This raises the question as to whether those with chronic diseases would benefit from practicing yoga or if they are at higher risk for specific adverse events compared to healthy individuals receiving the same instruction. METHODS: To address these questions, 328 adults who started practicing yoga for the first time…
Clinical effects of wasabi extract containing 6-MSITC on myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Wasabi (Eutrema japonicum) is a common pungent spice used in Japan. 6-Methylsulfinylhexyl isothiocyanate (6-MSITC) found in the rhizome of wasabi has been shown to have anti-inflammatory and antioxidant effects, as well as improve neuroinflammation and memory. Therefore, we hypothesized that these effects would be beneficial for treating myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The present study was conducted to in…
Effects of practicing yoga on alexisomia
BACKGROUND: Alexisomia refers to difficulties in the awareness and expression of somatic feelings. This idea was proposed by Dr. Yujiro Ikemi as a characteristic observed in patients with psychosomatic diseases and is based on his observations that patients with psychosomatic diseases have difficulty in the awareness and expression of not only their emotions, i.e., alexithymia, but also somatic feelings and sensations, i.e., alexisomia. He also p…
A patient who recovered from post-Covid myalgic encephalomyelitis/chronic fatigue syndrome
BACKGROUND: Some patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) complain of persistent fatigue, dyspnea, pain, and cognitive dysfunction. These symptoms are often described as "long COVID". Whether a patient with long COVID might develop myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is of interest, as is the treatment and management of ME/CFS in a post-COVID patient. Here I report a patient, …
Functional hyperthermia and comorbid psychiatric disorders
Disabling symptoms associated with increased axillary temperature in patients with functional hyperthermia
BACKGROUND: I previously reported a case of functional hyperthermia (FH) in a patient with an axillary temperature just slightly above 37.0 °C who persistently requested treatment. Because the severity of her fatigue increased remarkably when her axillary temperature increased above 37.0 °C, she felt that the temperature of 37.0 °C was disabling. In the present study, I analyzed a larger number of patients with FH to investigate the incidence of …
Medicine (26 works) · Internal Medicine (18 works) · Psychiatry (17 works) · Fibromyalgia and Chronic Fatigue Syndrome Research (13 works) · Physical therapy (13 works) · Chronic fatigue syndrome (11 works) · Psychosomatic medicine (11 works) · Psychology (10 works) · Psychosomatic Disorders and Their Treatments (9 works) · Alternative medicine (7 works)