Invited Review Articles
Mechanism of Cartilage Destruction in Osteoarthritis
NAOKI ISHIGURO, TOSHIHISA KOJIMA and A. ROBIN POOLE
pg(s) 73- 84
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Osteoarthritis (OA) is one of the most common diseases among the elderly. For many years, OA was considered a normal result of the aging process with few treatment options. Remarkable progress in understanding OA cartilage has been achieved in recent years. The application of technical advances to clinical studies of chondrocytes and cartilage tissue metabolism will provide important new insights concerning the pathophysiology of OA and identify new therapeutic strategies to regulate and inhibit the degenerative process of OA. However, many problems remain unresolved. In this review we try to focus on recent advances in the field of cartilage metabolism and molecular markers to facilitate the determination of a patient's prognosis and the need for cartilage protective treatment.
Functional Activation of Peroxisome Proliferator-Activated Receptor alpha (PPARalpha) by Environmental Chemicals in Relation to Their Toxicities.
TAMIE NAKAJIMA, GAKU ICHIHARA, MICHIHIRO KAMIJIMA, SEIICHIRO ITOHARA, TOSHIFUMI AOYAMA
pg(s) 85- 94
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Peroxisome proliferator-activated receptor alpha (PPARalpha) may work in the processes of both physiological and toxicological response to various endogenous or exogenous substances. The literature on the study of functional activation of PPARalpha by environmental chemicals in relation to their toxicities were reviewed. Environmental chemicals that were found to induce peroxisomes (peroxisome proliferators) and to activate the function of PPARalpha included plasticizers, herbicides, and organic solvents that have carboxyl groups in their parent substances or their metabolites. Several studies have showed species differences in the constitutive expression of PPARalpha and activation of PPARalpha, which may result in species differences in the induction of transcription of the genes encoding several peroxisomal enzymes. Although much information has supported the view that PPARalpha is primarily involved in the hepatic carcinogenicity of peroxisome proliferators, conflicting evidence exists. Most of the peroxisome proliferators have been shown to induce reproductive and developmental disorders, which might, in part. be associated with the functional activation of PPARalpha. Few epidemiological studies on the effect of peroxisome proliferators on humans have been conducted. The effect of perfluorooctanoic acid on humans was evaluated from the aspect of lipid metabolism in one study, which concluded that there was no effect.
Original Papers
Simple Exponential Regression Model to Describe the Relation between Minute Ventilation and Oxygen Uptake during Incremental Exercise
REIZO BABA, EMIKO MORI, NOBUO TAUCHI and MASAMI NAGASHIMA
pg(s) 95-102
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The physiological significance of an exponential regression model between minute ventilation (VE) and oxygen uptake (VO2) during incremental exercise was examined. Thirty-eight subjects, including 12 patients with chronic heart failure, participated in cardiopulmonary exercise testing on a bicycle ergometer. The equation VE = a e(bVO2), where a and b are parameters, was used to describe the relation between VE and VO2 during incremental exercise. Arterialized blood gas analysis was measured before and during exercise. The correlation coefficient of the regression model was high (r = 0.97 +/- 0.02). Parameter a negatively correlated with the arterial partial pressure of carbon dioxide during exercise (r = -0.44, p < 0.01), and positively correlated with peak VO2 (r = 0.47, p < 0.01). Parameter b negatively correlated with peak VO2 (r = -0.86, p < 0.01) and positively correlated with the dead space to tidal volume ratio (r = 0.68, p < 0.01). The regression model, as well as parameters a and b, is physiologically useful in expressing metabolic response to exercise. This model, a specific solution to the differential equation dVE/dVO2 = bVE, implies that the more a subject breathes, the greater is the increment in ventilation needed to meet a further increment of metabolic demand.
Total Hip Arthroplasty for a Patient with Angel-Shaped Phalango-Epiphyseal Dysplasia (ASPED). A Case Report.
HIDEKI WARASHINA, SINJI SAKANO, SINJI KITAMURA, KEN-ICHI YAMAUCHI, HIROSHI KITO and YUKIHARU HASEGAWA
pg(s)103-107
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Angel-shaped phalango-epiphyseal dysplasia is characterized by the angel shape of the middle phalanx and severe coxarthrosis in adult life. This osteochondrodysplasia shows a further variety of heterogeneous multiple epiphyseal dysplasias. It also shows a late and dysplastic development of the femoral head that leads to osteoarthrotic changes with severe hip pain and gait disturbance. In this report, we show a 35-yearold female with Angel-shaped phalango-epiphyseal dysplasia that was treated by bilateral total hip arthroplasty. She has suffered from her coxalgia since she was 27 and since the age of 30 has been able to walk with the aid of crutches. The radiographs of her bilateral hip showed severe osteochondrotic changes with a progressive disappearance of the joint space. Total hip arthroplasties were performed to treat the osteoarthrosis on the bilateral hip joint due to Angel-shaped phalango-epiphyseal dysplasia. One year after surgery, she is pain-free, and able to walk with a cane. Based on this case, we propose that total hip arthroplasty should be considered one of the treatments for the coxopathy in patients with Angel-shaped phalangoepiphyseal dysplasia.
Effects of Moderate Exercise on Metabolic Responses and Respiratory Exchange Ratio (RER)
KAORU TODA, YOSHIHARU OSHIDA, MIZUHO TOKUDOME, TOMOKO MANZAI and YUZO SATO
pg(s)109-113
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To counteract insulin resistance, it is necessary to increase the utilization rate of fatty acids in blood and adipose tissue. The aim of the present study was to determine the relation between metabolic responses and exercise duration from changes in the respiratory exchange ratio (RER). The mean RER during 30 minutes of moderate exercise (mean pulse 115 beats/min) was 0.89±0.02, indicating no major change. Significant changes were observed in the levels of plasma glucose (PG), plasma free fatty acid (FFA), and plasma immunoreactive insulin (IRI) before and after exercise, demonstrating a decrease in PG and IRI, and an increase in FFA levels. However, the RER value indicated that carbohydrate was the dominant metabolic substrate; therefore, prolonged or repetitive brief and mild to moderate exercise is necessary to increase the utilization of fatty acids.
Loneliness as Expressed by Schizophrenic Patients in the Early Remission Phase
JUNICHIRO KUDO, HAYATO MORI and TAKASHI GOMIBUCHI
pg(s)115-126
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We examine the clinical and psychotherapeutic significance of the "emotion of depression," particularly "loneliness," focusing on the postpsychotic depression in one phase of the early remission phase and prolonged early remission phase according to the so-called "remission process theory" of schizophrenia (Nakai). We first present details of two cases representative among 30 patients who discussed "loneliness" with their chief therapist. Then, in the Discussion, we classify the expressions of "loneliness" into four modes, taking "loneliness as isolation open to the other." In this phase, the patient strongly seeks a "deeply significant other" as a "partner for even a little protection against loneliness," and the therapist often assumes this role. This role is extremely important to the patient's passage through the early remission phase. We stress that the presence of this "partner for even a little protection against loneliness" is of great significance for the problems of subsequent progress or stagnation in the remission process, and the issue of ongoing deterioration as well.
Statistical Method in a Comparative Study in Which the Standard Treatment is Superior to Others
MITSURU IKEDA, KAZUHIRO SHIMAMOTO, TAKEO ISHIGAKI and KAZUNOBO YAMAUCHI
pg(s)127-132
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The statistical method in a comparative study in which the standard treatment is theoretically or practically superior to the others has been investigated for a matched-pairs design. We derived this statistical method from one based on the maximum likelihood and score methods. Here we have shown that the score test statistic is algebraically the same as the statistic from the maximum likelihood method. As an example of our method’s applications, we have considered a study on the detection of nodules on chest X-ray images displayed on a CRT with low luminance.