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Biomedical subjects

H Akagi

Publications and source records attributed to H Akagi.

At least 55 records · Page 3Linked to original sources
PubMed1998

Osteoma with cholesteatoma in the external auditory canal.

We report an unusual case of a 13-year-old girl with a benign osteoma associated with a cholesteatoma in the external auditory canal and serous otitis media. The osteoma was located in the antero-inferior wall of the right external auditory canal. A cholesteatoma was present between the osteoma and the tympanic membrane. Computed tomography revealed a soft tissue density within the external auditory canal and in the middle ear cleft. The shadow in the middle ear cleft was considered to represent the serous otitis media. Surgical removal of the osteoma and cholesteatoma proved successful, and no recurrences or complications have occurred in the first year postoperatively.

Adolescent↗
PubMed1998

Methylmercury dose estimation from umbilical cord concentrations in patients with Minamata disease.

The methylmercury exposure of patients with congenital or infantile Minamata disease is known only from a small number of analyses of umbilical cords. Four laboratories in Japan have analyzed a total of 176 samples of umbilical cord tissue obtained from Minamata. The highest concentrations were seen in cord tissue from children born during 1950-1965, i.e., the peak period of acetaldehyde production in Minamata before installation of waste water treatment. Twenty-four samples from patients diagnosed with Minamata disease showed a median mercury concentration of 1.63 microg/g and differed significantly from levels seen in cord tissue from control children. However, children diagnosed with mental retardation had mercury concentrations in cord that were intermediate between the two other groups. Using regression coefficients obtained at a study conducted at the Faroe Islands, the median cord mercury concentration from the children with Minamata disease is estimated to correspond to about 216 microg/L cord blood and 41 microg/g in maternal hair. Based on correlations reported in the literature, the median daily mercury intake of the women whose children developed Minamata disease can then be estimated at about 225 microg. Although these children had fully developed Minamata disease, the estimates of median mercury levels are only four to five times higher than current mercury exposure limits.

Dose-Response Relationship, Drug↗
PubMed1998

Methylmercury in fish and hair samples from the Balbina Feservoir, Brazilian Amazon.

The present study aimed to evaluate methylmercury in fish and human hair samples from an important hydroelectrical reservoir, Balbina (Brazil, Amazon). It presents a quite intense fishing activity and there is no known goldmining activity in its watershed. Fish and human hair were analyzed with a new extraction technique and measured by GC-ECD. Analytical quality was checked through intercomparisons between two laboratories with local samples and certified standards from IAEA. Methylmercury in hair ranged from 2.0 to 21.6 microg . g-1 with a mean of 8.76+/-5.20 microg . g-1 (N=20), while the methylmercury percentages were above 90. Fish presented methylmercury levels ranging from 0.03 to 0.9 microg small middle dot g-1 wet wt with a mean of 0.24+/-0.18 microg small middle dot g-1 wet wt (N=32), which is below the limit established for food by Brazilian legislation (0.5 microg small middle dot g-1 wet wt) and methylmercury mean percentages were above 95%. The total mean daily methylmercury intake ranged from 11 to 55 microg for 70% of the sampled population from the village based on a daily consumption of about 110 g of fish with methylmercury concentrations in the range of 0.1 to 0.5 microg . g-1. This calculation is consistent with methylmercury concentrations in hair samples in the range of 2.6 to 13.1 microg . g-1.

Adolescent↗
PubMed1998

Primary malignant lymphoma in the cerebellopontine angle.

Primary malignant lymphoma is an uncommon disease of the central nervous system (CNS). Immuno-compromised patients are at high risk of development of malignant lymphoma. We describe a case of primary CNS lymphoma presenting as a solitary cerebellopontine angle lesion. The patient had undergone extirpation of rectal cancer four years previously. Malignant lymphoma presenting as a cerebellopontine angle mass is extremely rare, with only 10 such cases (seven were primary, and the other secondary) previously reported.

Cerebellar Neoplasms↗
PubMed1998

Oncocytic carcinoma of the submandibular gland: a case report and literature review.

Oncocytes are characterized by a remarkable number of mitochondria as demonstrated by electron microscopy. Oncocytomas are very rare tumors that are usually benign and typically occur in the parotid gland. Oncocytic carcinomas are exceedingly rare in the salivary glands. We describe a 69-year-old Japanese man with an oncocytic carcinoma of the submandibular gland. We reviewed 38 articles describing oncocytic carcinoma of the head and neck that included clinicopathologic features. Oncocytic carcinomas appear to arise from benign oncocytomas, or may also arise de novo. In oncocytic carcinoma of the head and neck, the presence of distant, rather than local lymph node, metastasis is the most important prognostic indicator.

Adenocarcinoma↗
PubMed1998

Premorbid psychosocial behavior in demented patients.

We investigated the premorbid behavioral characters of demented patients in terms of life style, type A behavior, life events and coping behavior. We adopted the case control study. Significant differences were not found in the inventory scores of life style, passive coping behavior and type A behavior between dementia group and normal controls. However, the life events occurred significantly frequent in the vascular dementia group and the score of positive coping behavior was significantly low in dementia group. The results suggest that those life events and positive coping behavior might be related to the onset of dementia.

Adaptation, Psychological↗
PubMed1998

Origin and evolution of twin microsatellites in the genus Oryza.

An ancestral sequence of twin microsatellites of rice was found in a wild species. Twin microsatellite loci, RM20A and RM20B, were located on separate regions of chromosomes 11 and 12, which had been duplicated during rice evolution. These twin microsatellites showed different allele diversities in A genome species of the genus Oryza. This difference was caused by repetition of a simple sequence consisting of (TAA)n. Oryza longistaminata contains a short poly(A) sequence in this region instead of the poly(TAA) found in other species. A sequence comparison of RM20-related amplicons suggested that the poly(A)-containing sequence is the ancestral sequence of the RM20A and RM20B microsatellites. A simple base substitution in the poly(A) sequence may have produced the longer microsatellite motif (TAA). This mutation may have occurred on one of the chromosomes of a hypothetical ancestor of the A genome species before duplication of the chromosome segments.

Alleles↗
PubMed1997

Isolation of cDNA for an NADP-malic enzyme from Aloe arborescens.

NADP-malic enzyme catalyzes the reaction of decarboxylation from malate. In CAM plants, functions of this enzyme diverged to include both photosynthetic and non-photosynthetic roles. A full length cDNA for an NADP-malic enzyme was isolated from an 'obligate' CAM plant aloe (Aloe arborescens). The cDNA contains an ORF encoding 592 amino acid residues, whose sequence is highly homologous to the known plant NADP-malic enzymes. This gene is constitutively expressed in all organs in a low level. The amount of the transcript exhibited no diurnal variation, suggesting that this gene is not involved in photosynthetic functions.

Aloe↗
PubMed1997

Structure, chromosomal location and expression of a rice gene encoding the microsome omega-3 fatty acid desaturase.

The omega-3 fatty acid desaturases are membrane-bound enzymes catalyzing the conversion of linoleic acid to linolenic acid in lipids, and are located both in the microsome and plastid envelopes as two different isoforms. A cDNA encoding the microsome omega-3 fatty acid desaturase (OsFAD3) and the corresponding genomic clone were isolated from rice (Oryza sativa L.). The OsFAD3 gene was composed of 8 exons and 7 introns. A microsatellite was present in the second exon of the OsFAD3 gene, showing polymorphism between Indica and Japonica rice varieties. The mapping of this microsatellite showed that the OsFAD3 gene was located on chromosome 11. Expression of the OsFAD3 cDNA in tobacco hairy root tissues and subsequent analysis of fatty acid compositions demonstrated the activity of the microsome omega-3 fatty acid desaturase. The OsFAD3 mRNA was abundant in root tissues, but was hardly detectable in leaves. In root tissues, a high level of the OsFAD3 mRNA was observed at 15 degrees C and 20 degrees C, with its level decreasing markedly at temperatures below 10 degrees C. The accumulation of the OsFAD3 mRNA in leaf tissues remained at quite low levels, both at normal growth temperatures and at chilling temperatures. Similar temperature responses of the OsFAD3 gene were observed both in chilling- tolerant and in chilling-intolerant rice cultivars.

Chromosome Mapping↗
PubMed1997

[Improvements in mental and physical status of elderly patients with dementia after institutionalization--assessment with a minimum data set].

Using a Minimum Data Set, we studied how the mental and physical status of elderly people with dementia was modified by institutionalization. We assessed patients with dementia at the time of their admission in Kyoto Higashiyama geriatric hospital, and again three months later. On admission, both mental and physical problems were noted with a Resident Assessment Protocols. The former included cognitive loss/dementia, delirium, behavioral problem, activities, and mood state; the latter included visual function, activities of daily living (functional), urinary incontinence and indwelling catheter, nutritional status, dehydration/fluid maintenance, and dental care. Three months later, marked improvements were observed in 8 areas: delirium, psychological well-being, mood state, activities, urinary incontinence and indwelling catheter, nutritional status, dehydration/fluid maintenance and dental care. Cognitive loss/dementia and visual function were changed little. The unchanged areas were considered to be "core" manifestations of dementia, and those that changed were believed to reflect emotional problems and to be affected by the environment. Therefore, individualized care for elderly institutionalized patients with dementia should focus on these "peripheral" problems rather than on those that cannot be changed.

Activities of Daily Living↗
PubMed1997

[Evaluation of myocardial perfusion by 99mTc-tetrofosmin SPECT before and after emergent percutaneous transluminal coronary angioplasty for acute myocardial infarction].

To assess clinical performance of coronary perfusion in patients with acute myocardial infarction following successful PTCA, various 99mTc-tetrofosmin (TF) SPECT were obtained. Twenty-eight patients with acute myocardial infarction underwent TF SPECT before emergent PTCA (acute phase), after 7 days (subacute phase) and 4 weeks (chronic phase) later. Twenty-eight patients divided into 2 groups. Early group; time lug from onset of AMI till PTCA is 6 hours or shorter (n = 17), delayed group; time lug is more than 6 hrs (n = 11). The defect scores were graded by 4 points grading system (0 as normal to 3 as defect) in 14 myocardial segments. In early group, the mean defect score was 13 +/- 7 at acute phase, 6 +/- 5 at subacute phase, and 3 +/- 4 at chronic phase. In delayed group, the mean value of defect score at each phases were 18 +/- 7, 14 +/- 7, and 13 +/- 7. The improvement of defect score of early group was significantly larger than that of delayed group (p < 0.005). These data indicate that PTCA therapy for acute MI patients is useful particularly in the early stage following acute MI.

Aged↗
PubMed1996

Monitoring of fish and human exposure to mercury due to gold mining in the Lake Victoria goldfields, Tanzania.

Monitoring of environmental and human exposure to mercury in the Nungwe Bay area of the Lake Victoria goldfields, Tanzania, has revealed low mercury concentrations in fish (range: 1.8-16.9 ppb, mean: 7.0 ppb) and human hair (range: 156-5433 ppb, mean: 947 ppb) that represent background levels. Gold mining has not produced a significant increase in environmental methylmercury that is available for bioaccummulation in aquatic food chains. Urinary mercury levels in gold mine workers frequently exposed to Hg vapour in amalgamation and burning of amalgam were significantly higher (mean: 241 ng/ml) than those in the general mine population not occupational exposed to Hg (mean: 2.6 ng/ml). Rotation of mine duties reduced Hg exposure levels and hence the risk of intoxication in the gold mine workers. The lowest urinary and hair mercury levels were found in the Nungwe Bay fishing village population. This was consistent with the low mercury content of fish consumed by the inhabitants of the Nungwe Bay.

Animals↗
PubMed1996

Apoptotic process of cerebellar degeneration in experimental methylmercury intoxication of rats.

This report deals with the mechanism involved in the cerebellar degeneration following experimental methylmercury poisoning of male Wistar rats. The cerebellar granule cells of animals that exhibited typical hind leg paresis were shrunken and displayed marked nuclear pyknosis. At the ultrastructural level, the nuclei of these cells were condensed and fragmented, features which are characteristic of apoptosis. In situ staining for DNA strand breaks revealed that the pyknotic nuclei were positively labeled. DNA fragmentation was confirmed by agarose gel electrophoresis; a ladder pattern of multiples of approximately 200-base pair fragments, typical of apoptosis, was observed with the cerebellar DNA of the methylmercury-treated animals. These observations suggest that the degeneration of cerebellar granule cells by alkyl mercury compounds involves an apoptotic process.

Animals↗
PubMed1996

A computer-assisted operation for congenital aural malformations.

Surgical procedures to correct malformations of the external auditory canal are associated with the risk of facial nerve injury. We operated on a 6-year-old boy with a stenotic external auditory canal using a Viewing Wand (ISG Technologies Inc., Mississauga, Ontario, Canada) for improved visualization. We present our experience using this imaging system for aural surgery.

Child↗
PubMed1996

A volume-controlled liquid ventilator with pressure-limit mode: imperative expiratory control.

Liquid ventilation with perfluorocarbon (PFC) has been considered to offer advantages over gas ventilation to respiratory distress syndrome patients. We developed a volume-controlled liquid ventilator with pressure-limit mode; inspiration is performed mechanically with an actuator under the preset limit of the intratracheal pressure (Paw); expiration is performed by gravity assistance. Oxygenation and CO2 removal of PFC are done with a membrane oxygenator. An endotracheal tube with a Paw monitor line was placed in 5 rabbits weighing 2.7 +/- 0.6 kg, and liquid ventilation was conducted with the condition that the upper and lower limits of Paw were 20 and -20 mm Hg, respectively. The best arterial pH and gas tension were examined. The averaged arterial pH and gas tension were examined. The averaged arterial pH. Pao2, Paco2, and Sao2 were 7.45 mm Hg, 369 mm Hg, 46.2 mm Hg, and 100% at the best values, respectively. Ventilatory conditions at the best values were as follows: ventilation rates, tidal volume peak Paw, average Paw, and trough Paw were 5-15 (11 +/- 4) times/min, 13.3-17.3 (15.6 +/- 1.4) ml/kg, 5-18 (12 +/- 5) mm Hg, -7-4 (-1 +/- 4) mm Hg, and -20(-)-6 (-13 +/- 5) mm Hg, respectively. Pressure-limit control of the system worked well, but in the initial 3 animals, fluorothrax, that is the leakage of PFC into thoracic cavity, was recognized at the Paw from 20 to 25 mm Hg after the upper pressure limit was raised to 25 mm Hg to improve Paco2. The fluorothrax seemed to be caused by excess end-expiratory residual volume. An expiratory control mechanism appears to be imperative for further improvement of our liquid ventilator.

Animals↗