Biomedical subjects

K Makimoto

Publications and source records attributed to K Makimoto.

At least 19 recordsLinked to original sources

PubMed2005

Development of a nosocomial outbreak investigation database.

A pilot web-based database was created to facilitate epidemiological investigation of nosocomial outbreaks. The database provides highly structured abstracts in a case study format to serve as a guide for investigations. Problems encountered in abstracting over 330 published reports included missing information and classification of study methods. The database offers a new way to review outbreaks, for example, in terms of their impact measured by various combinations of database fields, such as the number of cases, attack rate, pathogens, service/ward and mode of transmission. Feedback from users of the database suggests its usefulness. Creation of a large web-based database seems to be both desirable and feasible.

Abstracting and Indexing↗

PubMed2001

An immunohistochemical examination of basaloid squamous cell carcinoma of the esophagus: report of a case.

We recently encountered a patient with basaloid carcinoma of the esophagus with extensive node involvement. The patient died of hematogenous metastasis 6 months after surgery. The tumor expressed cytokeratin but did not express either Type IV collagen or laminin. Both tumor cells and metastatic lesions in the regional lymph nodes expressed p53, Bcl-2, and Ki-67 proteins, but did not express cyclin D1 proteins.

Biomarkers, Tumor↗

PubMed2001

Spontaneous otoacoustic emissions in humans with endolymphatic hydrops.

OBJECTIVE/METHODS: The origin and clinical implications of spontaneous otoacoustic emissions (SOAEs) have not been well revealed. To investigate the relationship between the ear with endolymphatic hydrops and SOAE, SOAEs were measured in 31 patients with unilateral endolymphatic hydrops and 10 volunteers with normal hearing levels that had less than 25 dB hearing level (HL) on average for five frequencies (0.25, 0.5, 1, 2, and 4 kHz). RESULTS: SOAEs were detected in 18 (58%) of the 31 ears with hydrops. In 15 hydropic ears in which the hearing levels were less than 25 dB HL on average, SOAEs were observed in 11 (73%). The results of examining the relationship between changes in hearing level after administering the glycerol test and SOAE frequency showed that four (50%) of eight hydropic ears had SOAEs that were detectable between the frequency in which hearing level improved more than 5 dB and the frequency with no hearing level change in the audiogram. In 28 contralateral ears, except for three cases of delayed endolymphatic hydrops, SOAEs were detected in 17 (61%). In 14 contralateral ears in which the hearing levels were less than 25 dB HL on average for the five frequencies noted above, SOAEs were observed in nine ears (64%). In 20 normal ears, SOAEs were detected in eight (40%). Prevalence of SOAEs in hydropic ears and contralateral ears of the patients with unilateral hydrops tended to be greater than that in normal ears; however, there was no significant statistical difference between them. CONCLUSION: The present results suggest that it is not possible to mention the characteristics of SOAE in the hydropic ear only in terms of the prevalence of SOAEs. SOAEs may occur in a specific portion of the basilar membrane corresponding to the frequency in which hearing levels improve after the glycerol test, in some cases with endolymphatic hydrops.

Adult↗

PubMed2001

Response bias by neuroblastoma screening participation status and social desirability bias in an anonymous postal survey, Ishikawa, Japan.

OBJECTIVE: To examine response bias by neuroblastoma screening participation status in a population-based postal survey of parents in Ishikawa Prefecture, Japan. METHODS: The eligibility criteria for the study were: 1) parents whose infants were born in Ishikawa Prefecture between March 1997 and February 1998, and 2) of those parents who resided in the Prefecture in March 1999. Four-page questionnaires were mailed to one-third of screening participants (n = 2,886) and all the nonparticipants (n = 1,401). Questionnaires were anonymous, with no identifiers on the questionnaire. Colored papers were used for printing questionnaires to differentiate screening participation status. Response rates were calculated using demographic information on the infant registry as the denominator and demographic characteristics data from the returned questionnaire as the numerator. RESULTS: The response rate was 63% for participants and 33% for nonparticipants. The following factors were associated with lower response rates regardless of screening participation status: older maternal age (> or = 35 years), higher parity (> or = 4), nuclear family status, and mother having a full-time occupation. Approximately 20% of screening nonparticipants reported having participated in the screening. Place of residence, maternal age, and parity were associated with the percentage of incorrect reporting. CONCLUSION: Screening participation status was a major factor associated with low response rate, although some demographic characteristics were also predictive of low response rates. Incorrect reporting of screening participation among nonparticipants indicates a strong social desirability bias in this official survey in Japan.

Adult↗

PubMed2001

[Extracranial carotid artery bypass using artificial vessels--4 case reports].

We successfully completed extracranial carotid artery reconstruction in four cases (case 1: arteriosclerotic occlusion of the left common carotid artery between the origin at the aorta to just below the cervical bifurcation, case 2-4: combined removal of the carotid artery with malignant cervical tumor) using various types of synthetic vessels, e.g. 1) Double Velour Dacron, or 2) Expanded polytetrafluoroethylene. In case 2, Xenon CT under balloon occlusion was useful for revealing the indication for carotid artery reconstruction. Recent progress in the development of materials for use in synthetic vessels has remarkably improved the long-term patency of synthetic vessels, especially in medium to large size ones (larger than 6 mm in diameter). Synthetic vessels have the following advantages: 1. No need to harvest autogenous vessels, 2. An external shunt is available for patients with poor ischemic tolerance to temporary occlusion of the carotid artery, 3. A vessel of the most suitable size can be selected, 4. No risk of tumor invasion, 5. Easy suturing because the orifice of a synthetic vessel does not collapse. We report the usefulness, the indication for, and the surgical procedures of extracranial carotid artery bypass using synthetic vessels.

Blood Vessel Prosthesis↗

PubMed2000

Sensitivity of the endocochlear potential level to cochlear blood flow during hypoventilation.

To study the relationship between endocochlear DC potential (EP) and cochlear blood flow (CoBF) under hypoxic conditions, we recorded the EP and CoBF from the basal turn of the cochlea in 21 guinea pigs. Hypoventilation for 10 minutes was induced by reducing the respiratory rate and volume. During hypoventilation, the EP declined in most of the cases to an intermediate level of the positive range in a few minutes. At the midpoint of the 10-minute hypoventilation, angiotensin II (5 microg/kg or 1 mL/kg) was infused for 60 seconds to raise the systemic blood pressure. In this experimental manipulation of systemic blood pressure, the CoBF and EP generally rose transiently. We determined the sensitivity of the EP to a CoBF change (delta) by calculating the deltaEP/deltaCoBF. More specifically, we analyzed the relationship between the deltaEP/deltaCoBF and the EPi (EP level just before angiotensin II infusion). The deltaEP was equal to the maximum EP level after angiotensin II infusion minus the EPi. The deltaCoBF was equal to the maximum CoBF value after angiotensin II infusion minus the CoBF value just before infusion. The deltaEP/deltaCoBF increased most in the range near 70% of the EPi. That is, the deltaEP/deltaCoBF was greater and the EPi was lower in the range above 70% of the EPi. To elucidate this linear correlation in the range above 70% of the EPi, we must consider several factors. In the supplementary experiments for blood gas analysis using 11 guinea pigs, most of the data of the EPi in the range above 70% were found to be obtained under conditions of a PaO2 of more than 12 mm Hg. As to the sensitivity increase of the EP to the deltaCoBF above mentioned, we propose that among several factors in the stria vascularis during hypoxemia, the activation of glycolysis in aerobic metabolism may be involved. As another possible factor, we postulate the increase in the reactive rate of the enzymatic activities that are linked with EP production and respond to the elevated cyclic adenosine monophosphate activity induced by the sympathicotonic state due to hypercapnia.

Angiotensin II↗

PubMed2000

Is heavy alcohol consumption an attributable risk factor for cancer-related deaths among Japanese men?

BACKGROUND: Over the past four decades, per capita alcohol consumption in Japan has increased 4-fold. Age-adjusted cirrhosis mortality rates for men have also increased, whereas the rates for women have declined gradually. This widening difference in mortality could be due to a decreasing prevalence of viral hepatitis infection for both sexes and to differences in alcohol consumption between the sexes. Difficulties in estimating the impact of increased alcohol consumption on mortality rates in Japan also arise from changes in the prevalence of non-alcohol-related risk factors. METHODS: To measure the relative contribution of alcohol to death from cirrhosis, liver cancer, esophageal cancer, and head and neck cancer among Japanese men, we used the mortality rate for Japanese women as the standard because alcohol consumption for women has been low. We used published vital statistics data from 1992 to 1996 to calculate the attributable risk percent (ARP) in 5-year cohorts of Japanese men age 20 and older. RESULTS: Among Japanese men, heavy alcohol consumption accounted for 70.7% of deaths due to cirrhosis, 76.8% of liver cancer deaths, 88.5% of esophageal cancer deaths, and 87.4% of head and neck cancer deaths. When we examined ARPs by age group, ARPs for these four diseases were approximately 80% in the middle age groups. However, for older groups, the ARPs for cirrhosis and liver cancer were much lower than those for esophageal cancer and head and neck cancer. The prevalence of previous hepatitis C virus infection, considered to be the major cause of cirrhosis and liver cancer, increased with age. CONCLUSIONS: The results support previous epidemiologic studies conducted in Japan. Heavy alcohol consumption is a major public health problem among younger Japanese men, accounting for approximately 80% of the deaths for the four diseases examined.

Adult↗

PubMed1999

Comparison between the intravenous and esophageal-gastric administration of glycerol in changing cochlear blood flow and serum osmolarity in the guinea pig.

The effects of glycerol on cochlear blood flow and serum osmotic pressure were studied in healthy guinea pigs. Laser Doppler flowmetry of cochlear blood flow after the esophageal-gastric administration of 50% glycerol demonstrated a greater increase in blood flow for a longer time than with the intravenous infusion of 50% glycerol. The intravenous infusion of glycerol did increase systemic blood pressure, which changed partially in parallel with the change in cochlear blood flow. The change in systemic blood pressure after esophageal-gastric administration was slight. In another experiment designed to observe the changes in serum osmotic pressure after glycerol administration, the esophageal-gastric route also caused a greater and longer increase in serum osmolarity than intravenous infusion. The increase in cochlear blood flow after glycerol administration was thought to be due to an increase in the osmotic gradient between the blood in the cochlear vessels and the interstitial fluid, or to the high osmolarity of the blood itself. The possible mechanisms underlying local blood flow increase caused by high serum osmolarity are discussed. Systemic blood pressure increase induced by glycerol could be an influential factor for the cochlear blood flow increase during intravenous infusion.

Animals↗

PubMed1999

Variations and inconsistencies in maternal and child health indicators in Ishikawa Prefecture, Japan.

As part of a community health assessment, variations in maternal and child health-related vital statistics data in Ishikawa Prefecture, Japan, from 1984 to 1993 were studied. Annual vital statistics reports published by the Prefectural government were used for the analysis. The following rates by public health district were calculated: abortion rate, early fetal mortality rate, late fetal mortality rate, perinatal mortality rate, neonatal mortality rate, and infant mortality rate. Maternal mortality rates were calculated for the Prefecture because of the small number of events. A few northern public health districts had relatively high perinatal mortality and infant mortality rates throughout the study period. Cause-specific infant mortality rates showed that the northern region had higher infant mortality rates related to the level of perinatal care, injury, and poisoning. Inconsistencies in the pattern of mortality were found in one of the 10 public health districts. No indirect maternal deaths were reported for the 10-year study period. This study identified potential problems for perinatal care in some districts. Results also suggest the potential misclassification of vital events, such as fetal deaths, induced abortions, and maternal deaths.

Abortion, Induced↗

PubMed1999

Alcohol consumption as a major risk factor for the rise in liver cancer mortality rates in Japanese men.

BACKGROUND: Age-adjusted liver cancer mortality rates have been increasing for both men and women in Japan since 1970; however, increases in mortality rates in men are much greater than those in women. Hepatitis C virus infections and heavy alcohol consumption are considered to be the major risk factors of liver cancer deaths in Japanese. The purpose of this study is (1) to examine the pattern of liver cancer mortality by gender and birth year to compare those with the pattern of other alcohol-related mortality and (2) to estimate the attributable risk per cent of heavy alcohol consumption for liver cancer deaths in Japanese men. METHODS: Age-specific liver cancer mortality rates by gender were compared with those of cirrhosis mortality rates. Then male-to-female mortality rate ratios were calculated by birth cohort and compared with cirrhosis mortality rate ratios and oesophageal cancer mortality rate ratios. The attributable risk per cent of alcohol consumption for liver cancer death was calculated, using female liver cancer mortality rates as standard rates. RESULTS: Examination of both gender and birth cohort mortality rates revealed that male-to-female liver cancer mortality rate ratios by birth cohort correspond well with those rate ratios for liver cirrhosis and oesophageal cancer mortality. The attributable risk per cent of alcohol consumption for liver cancer deaths in Japanese men was 70%. CONCLUSION: Alcohol consumption is more important than hepatitis C virus infections as a major cause of liver cancer deaths in Japanese men.

Adult↗

PubMed1998

Comparative effects of glycerol and Urografin on cochlear blood flow and serum osmolarity.

Glycerol, an osmotic diuretic, has been used for the diagnosis and treatment of endolymphatic hydrops. Hearing improvements in hydropic ears are attributed to its dehydrating effect. In addition to this effect, glycerol also increases cochlear blood flow. Urografin, another hyperosmotic agent used for vasography, is similarly known to increase local blood flow. The present study compared these two hyperosmotic agents, glycerol and Urografin, in their effects on cochlear blood flow and serum osmolarity. Laser Doppler flowmetry on the lateral wall of the cochlea revealed that the increase in cochlear blood flow with a 30-min infusion (0.025 ml/min) of 76% Urografin continued for a longer time than with a 30-min infusion (0.025 ml/min) of 50% (v/v) glycerol. The significant increases appeared at 20 and 30 min after the infusion with the former; 10, 20, 30, 40, 50 and 60 min after the infusion with the latter. Intravenous infusion of these agents also caused elevation in serum osmolarity. This elevation was appreciably greater with Urografin infusion (maximal increase: about 30 mOsm on average) than with glycerol infusion (maximal increase: about 6 mOsm on average), and the former elevation appeared to be longer lasting than the latter. These differences were ascribed to differences between glycerol and Urografin with respect to the creation of an osmotic gradient across the capillary walls of cochlear blood vessels. Since glycerol penetrates the interstitial space and moves into inner ear fluids, the gradient may decline faster. It would be assumed that a higher concentration of the hyperosmotic agent in the capillary blood causes more vasodilatation and lowering of blood viscosity. Alternatively, direct action of these agents on the vascular wall may affect some biological processes, leading to vasodilatation in different degrees and durations with different agents. Hearing improvement with glycerol administration in hydropic ears was also discussed from the perspective of cochlear blood flow.

Animals↗

PubMed1998

Response of EP and cochlear blood flow to angiotensin II during hypoxic condition.

To understand the importance of oxygen transport to the inner ear tissue, we studied, using guinea pigs, the relationship between endocochlear DC potential (EP) and cochlear blood flow (CoBF) under hypoxic conditions. 33 guinea pigs weighing 200-400 g were used. EP and CoBF were recorded from the basal turn of the cochlea. Hypoxia (10 min) was induced by inspiring a mixture gas (2-10% oxygen in nitrogen). By inducing hypoxia, the EP declined to a intermediate level of the positive range in a few minutes. In the midpoint of 10-min loading of hypoxia, Angiotensin II (1 microg/kg, 1 ml/kg) was infused in 60 s, resulting in raising of systemic blood pressure (BP). Responding to this, CoBF and EP showed generally transient elevations (deltaCoBF, deltaEP) in accordance with BP change. Obtained data were analyzed for the value of deltaEP/deltaCoBF, which means the sensitivity of EP to CoBF change. Distribution of the value of deltaEP/deltaCoBF was found to be in a correlation with the EP level just before Angiotensin II infusion (EPi). That is, the sensitivity of EP to CoBF change became greater as a intermediate level of EP (EPi) was lowered in the range from 70 to 100% of EPi. Among several factors, we thought the hyperactivity of glycolysis in the stria vascularis may occur in such a mild hypoxemic condition. In addition to this, it could be presumable that cyclic AMP in the stria vascularis may increase by the sympathetic stimulation during hypoxemia, and increased cyclic AMP may produce more EP with a given O2 consumption.

Angiotensin II↗

PubMed1998

Drinking patterns and drinking problems among Asian-Americans and Pacific Islanders.

Researchers are increasingly investigating the drinking behavior and associated consequences among Asian-Americans and Pacific Islanders (APIs) in the United States. Among adolescents, APIs generally have lower rates of alcohol consumption and appear to be at lower risk for alcohol abuse compared with other ethnic groups. Similarly, the rates of drinking and heavy drinking have been found to be lower among API college students than among other ethnic groups. Among adult Asian-Americans, Japanese-Americans have the highest and Chinese-Americans have the lowest lifetime prevalence of drinking and heavy drinking. Southeast Asians (e.g., Vietnamese) living in the United States appear to be at high risk for heavy drinking. Numerous factors help determine the drinking patterns of APIs, including their economic status, educational attainment, and degree of acculturation as well as genetic and environmental factors, such as drinking norms and alcohol availability.

Alcohol Drinking↗

PubMed1997

Presenilin-1 polymorphism in Alzheimer's disease and vascular dementia.

Recent reports suggest an association between an intronic polymorphism at the 3' position of exon 8 of the presenilin-1 (PS-1) gene and late-onset Alzheimer's disease (AD), but little is known about its role in the pathogenesis of AD. By genotyping 193 Japanese patients with vascular dementia or AD, and 186 elderly control subjects, we have shown no association between vascular dementia and this PS-1 polymorphism, though PS-1 genotype 1/1 and allele 1 frequencies were both significantly higher among patients with AD than among controls. These results argue for a specific role of PS-1 allele 1 in the pathogenesis of AD, rather than suggesting a broader role for this allele as, for example, in vascular dementia.

Age of Onset↗

PubMed1997

Blood flow in common carotid and vertebral arteries in patients with sudden deafness.

Blood flow was measured in the common carotid artery (CCA) and the vertebral artery (VA) by the ultrasonic Doppler method in 14 male patients with sudden deafness and 70 normal adults. In the patients, blood flow on the affected side was slower than that on the normal side or that of the control group. Although these differences were not statistically significant in the CCA or in the VA, significant differences in the blood flow were noted between the group with a hearing loss of greater than 50 dB and the group with a loss of less than 50 dB. A negative correlation was found between blood viscosity and blood flow in both CCAs and both VAs. After stellate ganglion block (SGB), the blood flow of the CCA and VA increased on the side of the SGB and decreased on the opposite side. The changes in blood flow after SGB decreased with age, presumably because of changes in the blood vessel walls and a weaker response to sympathetic nerve receptors in the arterial wall.

Adult↗

PubMed1996

Effects of pentoxifylline and nitroprusside on guinea pig cochlear blood flow in relationship to various hematocrit values.

To understand better the microcirculation in the inner ear in relation to blood viscosity, we examined the effects of pentoxifylline (PXF) and nitroprusside (NP) on cochlear blood flow (CBF) in healthy adult guinea pigs in relationship to various hematocrit (H1) values. There was no correlation between Ht value and the maximum decrease of mean blood pressure after PXF infusion, whereas there was a positive correlation between Ht and the maximum increase in CBF. No such relationship was found after NP infusion. A graph plot of each animal's blood oxygen transport capacity (i.e., Ht/blood viscosity) was found to have a convex form and to increase with a shift of the peak to a higher Ht area after PXF infusion. These findings indicate that a decrease in blood viscosity may improve CBF and increase oxygen transport capacity of blood.

Animals↗

PubMed1996

Alpha-smooth muscle actin-positive stromal cells in cholangiocarcinomas, hepatocellular carcinomas and metastatic liver carcinomas.

AIMS/METHODS: In the human liver, alpha-smooth muscle actin (ASMA) is present in smooth muscle of the vasculature, perisinusoidal cells (Ito cells), and myofibroblasts derived from perisinusoidal cells. In this study, we investigated ASMA-positive stromal cells and their relation to tumor fibrosis in 50 cholangiocarcinomas, 30 hepatocellular carcinomas, and 57 metastatic liver carcinomas. RESULTS: Tumor fibrosis was much more extensive in cholangiocarcinomas and metastatic liver carcinomas than in metastatic liver carcinomas. ASMA immunoreactivity was prominent in the sinusoids surrounding cancer nodules and in the cancerous stroma, not in sinusoids remote from cancer nodules. ASMA-positive stromal cells were divisible into peritumoral ASMA-positive perisinusoidal cells and intratumoral ASMA-positive stromal cells. Both types of ASMA-positive cells were abundant in cholangiocarcinomas and metastatic liver carcinomas, but much more scanty in hepatocellular carcinomas. The number of both types showed a significant positive correlation with the degree of tumor fibrosis. The peritumoral ASMA-positive perisinusoidal cells were frequently in direct continuity with intratumoral ASMA-positive stromal cells in cholangiocarcinomas and metastatic liver carcinomas. CONCLUSIONS: These findings show that ASMA-positive stromal cells are related to tumor fibrosis in liver malignancies. Although direct evidence is lacking, the data suggest that, in cholangiocarcinomas and metastatic liver carcinomas, peritumoral ASMA-positive perisinusoidal cells transform into activated perisinusoidal cells (myofibroblasts), are incorporated into the tumor (intratumoral ASMA-positive stromal cells), and produce extracellular matrix proteins, that lead to tumor fibrosis. The scanty ASMA-positive cells in hepatocellular carcinomas may in part be responsible for the small amount of fibrosis in this tumor.

Actins↗

PubMed1996

Recurrent laryngeal papillomatosis developing into laryngeal carcinoma with human papilloma virus (HPV) type 18: a case report.

We report a case of recurrent laryngeal papillomatosis which developed into laryngeal squamous cell carcinoma 11 years after the first diagnosis. Interestingly, we could identify HPV type 18 DNA in the carcinoma tissue using the polymerase chain reaction (PCR). Other known risk factors of irradiation, smoking, exposure to chemical agents, or a hereditary tendency to malignant tumours were not present in this case. Our finding suggests that HPV type 18 is another aetiological agent for laryngeal carcinoma.

Carcinoma, Squamous Cell↗