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Biomedical subjects

H Imai

Publications and source records attributed to H Imai.

At least 397 records · Page 22Linked to original sources
PubMed1990

Interrelationship between the concentrations of some elements in the organs of Japanese with special reference to selenium-heavy metal relationships.

Multi-element analyses were conducted on internal organs (cerebrum, cerebellum, heart, spleen, liver and kidney) of Japanese obtained from 45 forensic medical autopsy cadavers. Elements analyzed and analytical methods were as follows: Ca, Cd, Cu, Fe, K, Mg, Na, P and Zn by inductively coupled plasma atomic emission spectrometry; total Hg (T-Hg) and inorganic Hg (I-Hg) by cold vapour atomic absorption spectrometry; methyl Hg (MeHg) by gas chromatography; and Se by fluorometry. A significantly positive correlation between Se and T-Hg was observed in kidney, liver, heart and spleen. The T-Hg/Se molar ratio was less than 1 in all the organs examined. The correlation between Zn and Cd was significant in liver and kidney. Multiple regression analyses using Se as a dependent and I-Hg, MeHg, Zn, Cd, Cu as independent variables were conducted on each organ. Inorganic Hg was a significant independent variable in kidney, whereas in liver and spleen it was MeHg. Cadmium was significant in explaining the variations in Se in liver and kidney medulla, indicating Cd-Se co-accumulation in humans.

Adolescent↗
PubMed1990

Magnetic resonance imaging of the cardiovascular system: application in function and tissue characterization.

Magnetic resonance imaging (MRI) is a new noninvasive technique for visualization of the cardiovascular system, and is used to evaluate tissue characteristics, cardiac function and blood flow abnormalities, as well as to obtain morphological information. In this paper we presented results of clinical and laboratory research obtained using conventional spin echo MRI with regard to cardiovascular anatomy, tissue characterization and physiology. Furthermore, experience with two new techniques, cine-MRI and volume-selected MR spectroscopy, and their potential clinical usefulness in detecting cardiovascular diseases are documented.

Cardiovascular Diseases↗
PubMed1990

Autologous transplantation of the superior cervical ganglion into the brain of parkinsonian monkeys.

The effect of autologous transplantation of the superior cervical ganglion (SCG) into the brain of parkinsonian monkeys was studied through quantitative measurement of animal behavior. The motor activity of the monkey was measured with a telemetry system during the experiment. After experimental parkinsonism was induced by repeated intravenous injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), three monkeys were treated with autologous transplantation of the SCG into both caudate nuclei. One monkey served as a control without SCG transplantation after MPTP treatment. Three SCG-transplanted monkeys showed biphasic (acute and chronic) behavioral amelioration of parkinsonism after transplantation. In the acute stage, the animals showed transient hyperkinesia with aggressive behavior and loss of circadian rhythm. In the chronic stage following acute hyperkinesia, the animals regained normal behavior and circadian rhythm without aggressiveness. In contrast with the transplanted monkeys, the control monkey failed to show recovery of the bradykinesia and muscle rigidity.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1990

[Echocardiography in patients with malignant metastatic neoplasms of the heart and great vessels].

Two-dimensional echocardiography was used to study malignant metastatic neoplasms of the heart and great vessels in 20 patients, 13 males and seven females, whose ages ranged from 15 to 72 years. Five patients had lung cancer; two each had breast cancer, malignant melanoma, hepatoma and one each had gastric cancer, urinary bladder cancer, adrenocortical carcinoma, malignant lymphoma, angiosarcoma, fibrosarcoma, leiomyosarcoma; and two had cancers with unknown primaries. Tumor invasion was demonstrated echocardiographically in the left atrium in one each with breast cancer, fibrosarcoma and gastric cancer; in the right atrium in two with hepatomas; in the right atrium and right ventricle in one patient with adrenocortical carcinoma; in the left ventricle in one with lung cancer; and in the pulmonary artery in one with malignant melanoma. Massive pericardial effusion was observed in 11 of 20 patients; two with pericardial tumors including malignant lymphoma and lung cancer. We conjectured that metastatic tumors in the right cardiac cavities came through the inferior vena cava, and other tumors in the left atrium, left ventricle and pericardium developed from direct extension of the primary lesions. There was an 80% mortality of the patients during the observation period, and the average survival period after the diagnosis of cardiac metastases was 5.5 months. However, one patient was still living after two years of radiation therapy and chemotherapy. Echocardiography proved a useful, non-invasive means for the detection and follow-up observation of metastatic cardiac tumors.

Adolescent↗
PubMed1990

[The effect of L-threo-DOPS on P-300 in parkinsonism].

The P-300 has been recently utilized as an objective electrophysiological index of cognitive function in some neurological disease. Hansch et al first described prolonged latency for the P-300 component in Parkinson disease patients and suggested these measures reflects a common, disrupted aspect of cognitive function in this disease. This cognitive disorder may be caused not only from the dysfunction of dopaminergic system but from non-dopaminergic lesions such as norepinephrine ones. On the other hand, L-threo-DOPS, a non-physiological precursor of norepinephrine, has been used for the treatment of some neurological illness such as the freezing phenomenon in Parkinsonism. In the present study we investigate the effect of L-threo-DOPS on cognitive function in Parkinsonism by measuring P-300 component succeedingly. Twenty-four patients, i.e. 19 cases of Parkinson disease (PD), 3 Juvenile Parkinsonism (JP) and 2 cerebrovascular Parkinsonism, are studied. The latencies of P-300 are significantly shortened after treatment of DOPS compared with those of the previous treatment and placebo administration respectively (p less than 0.05, p less than 0.01). The main factors which have influence upon these shortened latencies are analyzed multivariate analysis. The factor analysis and principal component analysis suggest three main factors such as DOPS, age (onset of age), and duration of illness. The patients' groups are divided into three by cluster analysis. The most effective group mainly consists of JP. The least effective one mainly consists of older, long-duration Parkinson disease patients. And there is another group which consists of younger, short-duration PD cases with moderate effect of DOPS. This tendency seems to suggest the different pathological findings between JP and PD. It is postulated that L-threo-DOPS would raise the level of attention and arousal mediated by norepinephrine neuronal system which may improve the cognitive disorder in Parkinsonism.

Aged↗
PubMed1990

Lipid composition of hepatitis B virus surface antigen particles and the particle-producing human hepatoma cell lines.

More than 90% of lipids of hepatitis B virus surface antigen (HBsAg) particles produced by two human hepatoma cell lines (huGK-14 and PLC/PRF/5) were composed of phospholipids, with phosphatidylcholine being the dominant component, accounting for more than 80% of total membrane lipids. Analysis of subclass compositions of phospholipids of HBsAg particles and the host cell lines revealed that 1,2-diacyl glycerophosphocholine was preferentially incorporated into the membrane of the HBsAg particles, although both host cell lines contained extremely high concentrations (more than 60% of total phospholipids) of ether-linked phospholipids. Phospholipids of other hepatoma cell lines (HuH-7, Hep-G2, and huL-1) which were not associated with hepatitis B virus (HBV) infection, were composed mostly of 1,2-diacylglycerophospholipids. Activities of dihydroxyacetone-phosphate acyltransferase, which is known to be an obligatory enzyme in ether lipid biosynthesis, were found to be elevated by three- to fourfold in both huGK-14 and PLC/PRF/5 cells compared to those of other hepatoma cell lines. The results suggest a possible relationship between HBV-induced hepatocellular carcinogenesis and the drastic change in the metabolism of membrane phospholipids.

Acyltransferases↗
PubMed1990

The use of the orthographic lexicon in reading kana words.

A lexical decision task was used to investigate the dual-route hypothesis that, in reading words conventionally written in katakana, a Japanese syllabic script, lexical access may be achieved by both a process of assembled segmental phonology and the use of a visual orthographic lexicon. The variables examined were lexicality (words and nonwords), kana type (katakana and hiragana), string length (long and short), and vocal interference (silence and concurrent vocalization). The main effects of the first three variables were significant, but more important, we found that subjects could be divided into two groups--phonological assemblers and orthographic lexicon users. Words that assume sighting were also identified. Collectively, the results were interpreted to uphold the dual-route hypothesis and to reject the common view that kana words are accessed on the basis of phonological mediation alone.

Adult↗
PubMed1990

[A case of primary early duodenal cancer].

Reported is a case of a suprapapillary primary early duodenal cancer in a 50 year old male patient who had had a hemicolectomy 15 years earlier for a colon cancer. The patient had undergone upper gastrointestinal endoscopy during a mass screening for abnormalities in the gastro-intestinal tract, and a slightly depressed lesion of the IIa + IIc type, 25 x 20 mm in diameter, was discovered accidentally at the superior duodenal flexure. The subsequent biopsy revealed a well differentiated tubular adenocarcinoma. Thus, the patient underwent a subtotal gastrectomy and a partial duodenectomy with a lymph node dissection. The histology of the resected specimen was the same as that of the biopsy, but only the mucosa was involved. Adenomatous lesions of the colon are known to occasionally accompany upper gastro-intestinal tumor, so that periodic gastro-intestinal scrutiny follow-ups are mandatory.

Adenocarcinoma↗
PubMed1990

[A case of tracheal calculus in the pathogenesis of which fungal infection was probably involved].

A 63-year-old woman with a past history of bronchial asthma was admitted to our hospital with a diagnosis of status asthmaticus. Examination revealed a ring-shaped, calcified stone within the trachea immediately below the vocal cords. As the patient complained of increasing difficulty in breathing, emergency tracheotomy was performed in an attempt to save her life, with success. Bronchial calculus (broncholithiasis) has been occasionally reported, and it is hypothesized that the calculus is mostly caused by intra-bronchial perforation of calcified lymph nodes around the bronchus. Tracheal calculus is a rare disease, and our case is only the third ever reported in Japan. However, perforation of calcified lymph nodes was probably not responsible for this case, which probably resulted from repeated chronic inflammation and fungal infection.

Calculi↗
PubMed1990

Allergic granulomatosis and angiitis (Churg-Strauss syndrome) presenting as acute acalculous cholecystitis.

A patient with bronchial asthma and hypereosinophilia developed acute acalculous cholecystitis. Histopathologic study of the surgically removed gallbladder revealed allergic granulomatosis and angiitis (Churg-Strauss syndrome). Allergic granulomatosis and angiitis having acute acalculous cholecystitis as an initial manifestation is rare. It should be recognized that acute acalculous cholecystitis may be the initial sign of a systemic vasculitis, specifically allergic granulomatosis and angiitis.

Acute Disease↗
PubMed1990

[Laboratory and clinical studies on norfloxacin in the pediatric field].

In bacteriological, pharmacokinetic and clinical studies on norfloxacin (NFLX, AM-715), the following results were obtained: 1. Antibacterial activity of NFLX, nalidixic acid (NA), amoxicillin (AMPC), cefaclor (CCL), erythromycin (EM) and fosfomycin (FOM) against clinically isolated bacteria was examined, and it was found that MIC80 of NFLX against Staphylococcus aureus was 3.13 micrograms/ml, thus NFLX exhibited stronger antimicrobial activity than NA, AMPC, CCL, EM and FOM. NFLX also showed good activities to those strains of S. aureus which were resistance to NA, AMPC, CCL, EM and FOM. 2. MIC80 of NFLX against Escherichia coli was 0.05 micrograms/ml or lower, thus NFLX showed better activity than NA, AMPC, CCL, EM and FOM. 3. In single oral administration at fasting of NFLX at dose levels of 1.5-2.4 and 2.5-3.4 mg/kg in tablet form mean peak values of serum concentration were 0.32 micrograms/ml reached in 1 hour and 0.38 micrograms/ml in 2 hours, T1/2's obtained were 1.7-4.0 and 2.2-2.9 hours and AUC's were 1.54 +/- 0.52 and 2.02 +/- 0.93 micrograms.hr/ml, respectively. Urinary recovery rates of 11.6-46.9%, 13.8-35.4% in 6-8 hours were demonstrated with the 2 ranges of dose levels, respectively. 4. NFLX was administrated to 34 patients consisting of 8 cases of acute pneumonia, 3 cases of acute tonsillitis, 3 cases of bacterial colitis, 19 cases of urinary tract infections and 1 case of purulent parotitis. The clinical efficacy rate was 97.1% including 34 cases with excellent results in 28, good in 5 and fair in 1. 5. The bacterial eradication rate was 96.8% (30/31) with one exception of a Campylobacter jejuni strain. 6. NFLX was given to patients according to a dosing regimen with 4.5-21.4 mg/kg/day dose levels for 3 doses daily except 1 case of UTI where 2 daily doses were given daily. 7. No adverse reactions were observed. Abnormal laboratory test value was obtained in 1 case where eosinophilia was found. The above results have suggested that NFLX is a useful and safe antimicrobial agent against bacterial infections in children.

Adolescent↗
PubMed1989

Studies on bilokinase, a biliary plasminogen activator: immunologic property and organ distribution.

The aim of the present study was to elucidate the immunologic difference between bilokinase, a plasminogen activator in bile, and urokinase, an urinary plasminogen activator, and to demonstrate the organ distribution of these antigens. Polyclonal antibodies against the highly purified activators (bovine-bilokinase, -urokinase and human urokinase) were raised in rabbits or guinea pigs. Immunologic precipitin reactions and quenching were found to occur only between the activators and their respective antisera. Histo-immunologic demonstration of the activators revealed that bilokinase-antigen was localized mainly in the hepatocytes as well as in the mucosa of the gall bladder, whereas urokinase-antigen was present in the epithelium of the urinary tubules. The liver may have a potential role in the hepatobiliary fibrinolytic system.

Animals↗
PubMed1989

Analysis of drug in tissue homogenates by high performance liquid chromatography with direct injection and column switching.

An HPLC method with direct sample injections and column switching was investigated for the analysis of drugs in tissue homogenates. The appropriate precolumn packings and analytical column packings were surveyed in order to obtain quantitative recovery. The use of a large bore end-fitting filter for the precolumn avoided the interference due to minute tissue particles. A minicolumn was used to trap the analyte or clean up the sample. The method was applicable to hydrophilic as well as hydrophobic drugs in liver, kidney or heart tissues, and has been extensively used in the determination of drugs in centrifugal cell fractions such as the nucleus, mitochondria and microsome.

Animals↗
PubMed1989

Interpretation of cutaneous pressure threshold (Semmes-Weinstein monofilament measurement) following median nerve repair and sensory reeducation in the adult.

Semmes-Weinstein nylon monofilaments are used to evaluate recovery of cutaneous pressure threshold in adults recovering from median nerve repair at the wrist level. Of the 46 patients studied, 22 received a program of sensory reeducation. The nylon monofilament measurements accurately described the improvement in recovered sensation following nerve repair. There was a statistically significant better recovery (lower threshold) in patients receiving sensory reeducation, which was present in those less than 30 years old (P less than .003) as well as those greater than 30 years old (P less than .05). However, normal thresholds were not recovered in these patient populations.

Adult↗
PubMed1989

Results of median nerve repair in children.

Seven children ranging in age from 1 to 13 years (mean 8 years) were evaluated at a range of 8 months to 15 years (mean 4.7 years) following group fascicular repair of the median nerve at the wrist following a sharp transection of the nerve. At the follow-up evaluation, they were measured with Semmes-Weinstein nylon monofilaments, moving and static two-point discrimination, and were judged for the presence or absence of paresthesias in their hands. The children did not receive sensory reeducation in the postoperative period. All children recovered to normal levels of moving and static two-point discrimination and were free from disabling paresthesias. These results are contrasted with a group of similar nerve injuries in adult patients treated in the same way and over the same period of time. It is concluded that the capacity for peripheral neural regeneration and cerebral plasticity in children is such that excellent recovery of functional sensation in the hand can occur without the need for sensory reeducation.

Adolescent↗
PubMed1989

A case of neurofibroma located in the retroperitoneum involving the uncinate process of the pancreas.

A case of solitary neurofibroma in the retroperitoneum involving the uncinate process of the pancreas, which has been reported in only one case in Japan and less than 20 cases in the world literature, is described. A 57-year-old male complained of back pain and microhematuria. Plain and enhanced abdominal computed tomography (CT) indicated an 8 x 6 cm hypovascular tumor located in the uncinate process. We initially assumed it to be a cancer of the pancreas. His physical examination and blood chemistry result were normal. Various diagnostic imaging methods however, disclosed a rare type of tumor. The tumor was resected by pancreaticoduodenectomy and histological examination revealed it to be neurofibroma.

Humans↗