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Biomedical subjects

Katsumi Yoshida

Publications and source records attributed to Katsumi Yoshida.

At least 19 recordsLinked to original sources
PubMed2006

Development of subclinical hyperthyroidism due to Graves' disease in a hypothyroid woman who had undergone hemithyroidectomy for adenomatous goiter and radiotherapy for nasopharyngeal cancer.

A variety of thyroid disorders develop following external radiation to head and neck cancers. Hypothyroidism is the most common clinical consequence of the radiotherapy and lifelong thyroid hormone replacement is required in many cases. Patients who received both hemithyroidectomy and the external radiation to the neck are at especially high risk for permanent hypothyroidism. Here we report an unusual case with radiation-induced hypothyroidism who had undergone hemithyroidectomy for adenomatous goiter 8 years before the radiotherapy for nasopharyngeal cancer and subclinical hyperthyroidism due to Graves' disease developed during thyroxine replacement therapy. Thus subclinical hyperthyroidism due to Graves' disease can develop in patients with radiation-induced hypothyroidism even if they have undergone hemithyroidectomy for thyroid nodules. Therefore careful and periodic evaluation of thyroid function is required even on adequate thyroxine replacement therapy.

Adult↗
PubMed2006

Effects of perinatal exposure to low doses of cadmium or methylmercury on thyroid hormone metabolism in metallothionein-deficient mouse neonates.

Perinatal exposure to cadmium (Cd) or methylmercury (MeHg) results in impaired neurodevelopment. Thyroid hormone is essential for normal brain development. However, the issue whether Cd or MeHg, especially at low doses, interrupts thyroid hormone action remains to be investigated. In the present study, effects of perinatal exposure to low levels of Cd or MeHg on thyroid hormone metabolism were examined using metallothionein I and II (MT-I/II) null or wild-type neonatal mice. Dams were exposed to 10 mg/L water of Cd or 5 mg/kg chow of MeHg from gestational day 0 to post-natal day 10 (PND 10). Sera, livers and brains were collected from neonates on PND 10. Iodothyronine deiodinase activities and serum thyroxine (T4) concentrations were measured. MeHg exposure failed to induce changes in serum T4 levels and liver type 1 deiodinase (D1) and brain type 2 deiodinase (D2) activities regardless of the MT genotype. However, exposure to MeHg resulted in a decrease in brain type 3 deiodinase (D3) activity in MT-I/II null and wild-type neonates. In contrast, exposure to Cd resulted in a decrease in serum T4 levels in MT-I/II null neonates. Consistently, brain D2 activity was increased in Cd-exposed MT-I/II null neonates. No significant changes in liver D1 and brain D3 activities were induced by Cd administration. Our study demonstrates that perinatal exposure to low doses of Cd or MeHg can induce changes in brain deiodinase activities in the neonates, suggesting that thyroid hormone metabolism in fetuses and neonates might be a potential target of Cd and MeHg.

Administration, Oral↗
PubMed2006

Assisting the diagnosis of thyroid diseases with Bayesian-type and SOM-type neural networks making use of routine test data.

Patients with hyperthyroidism sometimes take much time to receive the final diagnosis. To improve patient QOL, simple screening for hyperthyroidism by thyroid non-specialists at the physical check-up is highly expected. Therefore, we applied both Bayesian-type and SOM-type neural networks since we assured the approach useful in analysing thyroid function diagnosis in the previous work. Routine test (14 parameters) data from 66 subjects with a known diagnosis (18 patients with hyperthyroidism and 48 healthy volunteers) were adopted as learning data, and then 142 individuals who also received the same routine tests at the Tohoku University Hospital were screened to predict patients with hyperthyroidism. Both neural networks using 14 parameters predicted several patients as having hyperthyroidism with high probability, including all three hyperthyroid patients diagnosed later by the physician. Further detailed analysis of the routine test parameters that were important for classification found that screening with a set of three parameters (alkaline phosphatase, serum creatinine and total cholesterol) or plus aspartate aminotransferase allowed for quite accurate screening. These results showed that the same neural networks as previous work allows simple screening of patients for hyperthyroidism on the basis of routine test data, and that physicians not specializing in the thyroid can rapidly identify individuals suspected of having hyperthyroidism, to permit a rapid referral for examination and treatment by thyroid specialists.

Bayes Theorem↗
PubMed2006

Dissolution of functional materials and rare earth oxides into pseudo alveolar fluid.

The dissolution rates of rare earth oxides and two types of rare earth containing functional materials into water, saline solution, and Gamble's fluid were measured in order to evaluate the biological effects of rare earth-containing functional materials. The tested materials were yttrium, lanthanum, cerium and neodymium oxides, and neodymium-boron-iron magnet alloy (NdBFe) and lanthanum-mish-metal-nickel-cobalt (LmNiCo) hydrogen-containing alloy. The dissolution rates of the rare earth oxides were very low, resulting in concentrations of rare earth elements in the test solutions of the order of ppb. In the most extreme case, Gamble's fluid dissolved 1,400 times more of the rare earth oxides than pure water. Fairly high concentration of neodymium were found in the dissolving fluids, which means that trace neodymium present as an impurity in each rare earth oxide dissolved preferentially. For yttrium oxide, the ratio of neodymium to yttrium that dissolved in the saline solution was greater than 78,000 to 1, taking into account the amount of each that was originally present in the yttrium oxide.

Bronchoalveolar Lavage Fluid↗
PubMed2006

[The relationship of autonomic functional disturbance and atherosclerosis in type 2 diabetes].

The aim of the study was to assess the relationship between the autonomic nerve disturbance and atherosclerotic changes in patients with type 2 diabetes. Aortic distensibility and max carotid intima-media thickness (Max IMT) were evaluated using brachial ankle pulse wave velocity (PWV) and high-resolution B-mode ultrasonography, respectively, in 135 patients (69 men, 66 women, 57 +/- 16 years) with type 2 diabetes. The autonomic neuropathy was evaluated using coefficient of variation of the RR interval (CV(R-R)) of electrocardiograms recorded at rest in a supine position. There was a significant negative correlation between CV(R-R)and Max IMT (r= -0.488, p< 0001). There were also significant negative correlations between CVR-(R a)nd the left and the right PWV(r=0.518, p<0.001; r=0.551, p<0.001, respectively). Patients with normal Max IMT, but decreased CVR-R, had a high PWV compared to patients with normal Max IMT and normal CVR-(R. )Therefore, decreased CVR-(R i)n type 2 diabetic patients may reflect atherosclerotic changes. Thus, the measurement of CVR-(R i)s a simple and quantitative test for assessing atherosclerotic as well as neuropathic complications in diabetic patients.

Atherosclerosis↗
PubMed2006

[Comparison between optical microscopic examination and phase contrast microscopic examination for diagnosing the origin of urinary bleeding].

PURPOSE: Phase contrast microscopy method is useful in the examination of urine sediment to differentiate glomerular(Gl) hematuria from non glomerular(nonGl) hematuria. In this study, we compared the diagnostic value of optical microscopy with that of phase contrast microscopy. METHOD: One hundred and sixty fresh urine samples of microscopic hematuria(5/HPF or more) from 118 patients with renal disease and 42 patients with urologic disease were analyzed. The erythrocytes referred to as Gl, are defined to have acanthocytes, target configuration, or finger ring shape, and a Gl cell/total erythrocyte ratio greater than 3% is defined as reliable marker for Gl bleeding. RESULT: Sensitivity and specificity of this criteria for Gl bleeding were 50.9% and 94.9% in acanthocytes, 69.6% and 89.1% in the target configuration, and 88.4% and 89.1% in the finger ring, respectively. As for the microscopic observation methods, the sensitivity and specificity of this criteria for GI bleeding were 88.1% and 81.0% with phase contrast microscopy, 74.6% and 90.9% with optical microscopy with no dyeing, and 74.6% and 88.6% with optical microscopy with dyeing, respectively. CONCLUSION: GI and nonGl hematuria were correctly diagnosed by counting the urinary Gl cells not only by phase contrast microscopy, but also by optical microscopy. This method seems to have important clinical usefulness by offering information on urinary bleeding.

Adolescent↗
PubMed2006

[Role of medical technologists in the infection control team].

The infection control team (ICT) plays important roles in many different aspects of infection control. They include (1) surveillance for hospital-acquired infection, (2) developing the infection control manual, (3) checking that the manual is followed correctly, (4) giving information about the isolation of microorganisms in the hospital, (5) educating and instructing medical staff, etc. Many data have been accumulated on a database in the microbiology laboratory. Bacterial samples are also examined in the microbiological laboratory therefore medical technologists will be the first to notice hospital-acquired infection. Offering prompt information, obtained by surveillance or routine work, greatly contributes to infection control. Furthermore, a 24hr system for the microbiological laboratory may prevent occupational infection of health care workers. The role of the medical technologist in ICT is thus important. To prevent outbreaks of infection, the regional network is also important for the collection of information about the pathogen and the susceptibility of antimicrobial agents in the region. The medical technologist should participate in and communicate with this network. As mentioned above, the inclusion of medical technologists in infection control practice is essential. To participate in the ICT, medical technologists need to have communication skills, and be recognized by other team members as an essential member.

Bacteria↗
PubMed2006

[Significance of urine dipstick test for occult blood in patients with diabetes mellitus].

OBJECTIVE: Hematuria is the usual urinary finding in patients with diabetic nephropathy. In this study, prevalence and significance of microhematuria in patients with diabetes mellitus were investigated. MATERIAL AND METHODS: Five hundred and forty-two samples from outpatients, who consulted the Department of Diabetes and Metabolism, were categorized into 4 groups according to the results of the urine dipstick test. Group I :258 samples, urinary protein(u-P) 1+ and occult blood (OB) negative, group II: 95 samples: u-P 1+, OB 1+ approximately 3+, group III: 89 samples: u-P 2+ approximately 3+, OB negative, group IV 100 samples u-P 2+ approximately 3+, OB 1+ approximately 3+. RESULTS: Serum concentrations of creatinine and highly sensitive CRP were both significantly higher in group II than in group I . Those parameters were also significantly higher in group IV than in group III. CONCLUSIONS: These results indicate that a positive dipstick test for OB may occur in many patients with diabetes mellitus and suggest the progress of renal damage.

Creatinine↗
PubMed2005

Methylmercury inhibits type II 5'-deiodinase activity in NB41A3 neuroblastoma cells.

Methylmercury (MeHg) is a well-known neurotoxicant and prenatal exposure to MeHg results in severe brain damage. Since MeHg has a high affinity for thiol groups, we sought to determine whether MeHg inhibited type II iodothyronine deiodinase (D2) activity, by which prohormone thyroxine (T4) is converted to active thyroid hormone, 3,5,3'-triiodothyronine (T3) in the brain, using NB41A3 mouse neuroblastoma cells. In MeHg-treated cells, D2 activity was inhibited in a dose- and time-dependent manner; relatively low concentrations of MeHg (30 nM) inhibited D2. Kinetic analysis using a double reciplocal plot of D2 activity revealed competitive inhibition by MeHg. DTT protected D2 from MeHg when cells were incubated with both MeHg and DTT or when MeHg was added to the assay buffer containing DTT and cell sonicates from untreated cells. Removal of MeHg from culture medium did not recover D2 activity. These results demonstrate that MeHg inhibited D2 activity in NB41A3 cells and the selenocysteine in the catalytic subunit of D2 may be involved in the inhibitory action of MeHg. Further our results suggest that T3 deficiency due to D2 inhibition in the brain may be involved in the neurotoxicity of MeHg.

Animals↗
PubMed2005

Musculoskeletal pain in Japan: prevalence and interference with daily activities.

We estimated the prevalence of musculoskeletal pain in five anatomical areas and their interference with daily activities (IDA) in a Japanese adult population (n = 3188). A questionnaire survey was conducted among participants in health examinations at three health care centers. On a drawing with predefined body regions, participants marked the regions affected by pain and the regions affected by IDA due to the pain, respectively. Overall prevalence of musculoskeletal pain was 41.4% (M 40.9%, F 42.2%) with a significant increase with age. Neck and shoulder area showed the highest prevalence of pain (20.3%; M 19.6%; F 21.3%), followed by lower back area (19.1%; M 20.1%; F 17.5%), hip and knee area (11.1%; M 9.1%; F 14.3%), elbow, wrist, and hand area (7.4%; M 6.6%; F 8.6%), and ankle and foot area (5.8%; M 5.5%; F 6.3%). Overall percentage of IDA in musculoskeletal pain was 20.5%. After adjustment for age and sex, the ranking of percentage of IDA in the pain was: (1) neck and shoulder area (31.0%), (2) elbow, wrist, and hand area (21.5%), (3) ankle and foot area (18.8%), (4) lower back area (17.9%), and (5) hip and knee area (17.4%). Overall percentage of treatment for musculoskeletal disorders was 6.6% (M 4.7%, F 9.7%), which remained 28.1% (M 21.6%, F 38.0%) even in those who described IDA due to pain. According to our estimates, 42.2 million (41.2%) of Japanese adults might suffer from musculoskeletal pain and 9.1 million (8.8%) might encounter IDA due to the pain. Because of high prevalence and IDA, musculoskeletal pain is one of the health problems to be given high priority in Japan.

Journal Article↗
PubMed2005

Burden of musculoskeletal pain in Japan.

Based on the prevalence of musculoskeletal pain in the context of interference with daily activities (IDA) and treatment for musculoskeletal disorders in the study population (n = 3188), we estimated the prevalence and years lived with disability (YLD) of musculoskeletal pain in Japan. The total of 42,287 thousand (41.2%) of Japanese adult people was estimated to suffer from musculoskeletal pain. Among them, 9127 thousand was estimated to interfere with daily activities due to the pain. Overall YLD for musculoskeletal pain in Japan were estimated at 1,297,843.7 (1263.6 per 100,000). The YLD for Pain without IDA were 33,159.3 (32.3 per 100,000) and the YLD for Pain with IDA were 1,264,684.4 (1231.3 per 100,000). One-way sensitivity analysis showed that the YLD of musculoskeletal pain might increase to 4,421,844.0 (4305.2 per 100,000) with the increased disability weight for Pain without IDA of 0.1, while they might inversely decrease to 1,018,875.0 (992.0 per 100,000) with the increased treatment rate in Pain with IDA of 100%. Musculoskeletal pain imposes a substantial burden on the Japanese adult population. To allow the population to keep their health-related quality of life, health professionals should pay more attention to musculoskeletal pain and make positive efforts to improve prevention and control of musculoskeletal pain.

Journal Article↗
PubMed2005

Recovery of human compound action potential using a paired-click stimulation paradigm.

The recovery process from adaptation of the compound action potential (CAP) was studied using an equilevel paired click stimulation paradigm in humans with normal hearing. The CAP amplitude to the second click of paired clicks was normalized to the amplitude to the first click. The second-click CAP amplitude recovered as a function of interclick interval (ICI) between the first and the second click of a pair. A regression line fitted to the recovered amplitude data demonstrated the logarithmic function of the ICI. Full recovery times changed from 118 to 278 ms with increasing click intensity. The regression lines for higher click intensities exhibited two different slopes in two ICI ranges: from 3 to 100 and 120 to 300 ms. We suppose that the CAP recovery for ICI <100 ms is attributable to both the relative refractoriness of auditory nerve and the short-term adaptation mechanisms, while, for ICI >100 ms chiefly to the short-term adaptation mechanisms. The recovery process of the second-click CAP slowed with increasing intensity, which is a similar result to that obtained in the animal experiments by Parham et al. The input-output (I-O) curve of the second-click CAP amplitudes exhibited a different slopes above and below 60 dB normal hearing level (nHL). We assume that the mechanisms underlying this characteristic curve pattern differ from those for the I-O curve of the CAP in response to single-click stimuli. We expect that investigating the CAP recovery in pathological ears will provide clinically useful information on cochlear synaptic function.

Acoustic Stimulation↗
PubMed2005

Relationships between erectile dysfunction, depression, and anxiety in Japanese subjects.

AIMS: This study aimed to elucidate the relationships between erectile dysfunction (ED) and depression or anxiety. METHODS: Subjects were 1,419 Japanese men aged 40-64 years. ED was assessed by the International Index of Erectile Function 5 (IIEF-5) score (Japanese version), and depression and anxiety symptoms were assessed by the Hospital Anxiety and Depression Scale (HADS). In this study ED cases were defined as those whose IIEF-5 value was less than 12, and a score of 8 or higher was used to classify a subject as suffering from depression or anxiety, respectively. The prevalence odds ratio (OR) of ED was calculated with confidence interval (CI) estimated by the Woolf's method by five age groups (40-44, 45-49, 50-54, 55-59, 60-64 years). To control for age, body mass index, smoking, and alcohol drinking factors, we conducted the multivariate logistic regression analysis for calculating adjusted ORs and 99% CIs. RESULTS: ED was significantly associated with depression in age groups 45-49 (OR 3.42, 99% CI 1.51-7.76) and 50-54 years (OR 2.43, 99% CI 1.11-5.35). After using multivariate analysis, adjusted OR also showed statistical significance. (OR 2.02, 99% CI 1.32-3.08). ED was significantly associated with anxiety in the 50-55-year-old age group (OR 2.48, 99% CI 1.12-5.47). After using multivariate analysis, adjusted OR also showed statistical significance (OR 1.77, 99% CI 1.15-2.72). The concomitant depression and anxiety group (A+D+) had significantly higher prevalence of ED than the control group (A-D-) in both the 45-49 and 50-54 age groups. (P < 0.01) CONCLUSION: ED associated significantly with depression and anxiety status only in late 40s to early 50s (45-55 years) in male Japanese. Furthermore, comorbidities of depression and anxiety strengthen this association. Our results might be useful in furthering understanding of ED etiology and determining a target population for prevention in ED subjects.

Adult↗
PubMed2005

Autoinduction of tumor necrosis factor-alpha in FRTL-5 rat thyroid cells.

Tumor necrosis factor-alpha (TNFalpha) may play a role in the development of autoimmune thyroiditis such as Hashimoto's thyroiditis. In the present study, we examined whether TNFalpha induced its own expression in FRTL-5 rat thyroid cells. Lipopolysaccharide (LPS) markedly increased TNFalpha mRNA levels in FRTL-5 cells as assessed by semiquantitative RT-PCR. In addition, LPS-stimulated cells released TNFalpha protein into the culture medium. Similarly, TNFalpha induced its own gene and protein expression in FRTL-5 cells as assessed by RT-PCR and metabolic labeling and immunoprecipitation of TNFalpha. The autoinduction of TNFalpha gene was also observed in TNFalpha-stimulated human thyroid epithelial cells. TNFalpha induction was specific to LPS and TNFalpha since interferon-alpha or amiodarone failed to increase TNFalpha mRNA levels in FRTL-5 cells. Human TNFalpha induced rat TNFalpha gene expression, indicating that type 1 TNF receptor (TNF-R) is involved in the autoinduction. TNFalpha did not increase either type 1 or type 2 TNF-R mRNA levels, suggesting that upregulation of TNF receptors is not involved in the autoinduction of TNFalpha. Although the biological significance of autoinduction of TNFalpha remains unclear, our results suggest that thyroid epithelial cells may participate in the development of autoimmune thyroiditis through production of TNFalpha. Furthermore, inhibition of TNFalpha production in the thyroid may represent a novel approach to mitigating inflammation in autoimmune thyroiditis.

Actins↗
PubMed2005

[The relationships between autonomic function and heart rate in essential hypertension].

The circadian variation of blood pressure (BP) may be mediated at least in part by circadian variation of autonomic nervous system activity. In the present study power spectral analysis of hourly R-R intervals for 24 hours was done to obtain the low frequency variability (LF: 0.04 to 0.15Hz) and high frequency variability(HF: 0.15 to 0.40Hz) in 93 patients with untreated essential hypertension. LF/HF ratio and HF were considered to be an index of sympathetic nervous activity and parasympathetic nervous activity, respectively. The relationship between heart rate (HR) and systolic blood pressure (SBP), diastolic blood pressure (DBP), HF, and LF/HF was examined. Both SBP and DBP were correlated positively with HR(r = 0.28, p < 0.05 and r = 0.27, p < 0.05, respectively) in the daytime. HF was correlated negatively and significantly with HR in both daytime and nighttime (r = -0.40, p < 0.05, and r = -0.38, p < 0.05 respectively). After averaging for SBP of 24 hours, HR in the patients whose SBP was 135mmHg or more was significantly higher than that in the patients whose SBP was less than 135mmHg. These results suggest that the decreased parasympathetic nervous activity seems to be responsible for the rise in BP.

Aged↗