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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 829 records · Page 46Linked to original sources
PubMedDate not supplied

Serial IMP-SPECT and EEG studies in an infant with hemimegalencephaly.

An 8-month-old girl of hypomelanosis of Ito associated with hemimegalencephaly had frequent seizures beginning 44 h after birth. The seizures were secondarily generalized or unilateral initially, followed by infantile spasms at about 1.5 months of age. Frequent partial seizures appeared at 4 months of age. [123I]N-Isopropyl-p-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) was performed serially during an interictal period at 1, 3 and 7 months of age. At 1 and 3 months, IMP-SPECT showed a marked increase of IMP uptake in the pathological left hemisphere and electroencephalography (EEG) revealed left-sided dominant hypsarrhythmia. At 7 months of age, a reversal was seen, there being decreased uptake on SPECT in the pathological hemisphere and abundant high amplitude background activity mingled with epileptic discharges on EEG in the non-pathological hemisphere. These serial changes of IMP uptake on SPECT seemed to reflect either changes in epileptic activity or maturational changes in cerebral perfusion in hemimegalencephaly.

Age Factors↗
PubMedDate not supplied

Dandy-Walker cyst associated with occipital meningocele.

Dandy-Walker cyst associated with occipital meningocele is very rare. Only 12 patients have been reported. We report a female infant with Dandy-Walker cyst and occipital meningocele whose diagnosis was suspected antenatally by in utero ultrasonography. At birth, head circumference was normal for 37 weeks gestation. She underwent surgical repair of the occipital meningocele immediately after birth. The post-operative course was uneventful until the sixth day of life when progressive enlargement of the head with progressive ventricular dilatation was recognized. Communication between the posterior fossa cyst and the occipital meningocele was confirmed neuroradiologically; the occipital meningocele may have compensated for the increased intracranial pressure in fetal life.

Dandy-Walker Syndrome↗
PubMedDate not supplied

Fungal pseudotumor masquerading as pancreatic cancer-a sequela of new technology?

Fungal infection resulting in chronic pancreatitis is rare. We report a case of chronic pancreatitis due to fungal infection causing common bile duct obstruction and abdominal pain mimicking pancreatic cancer. Treatment included resection to cure the pain and rule out malignancy. Long-term effects of fungal infection may be seen more frequently as total parenteral nutrition, antibiotics, and foreign bodies (e.g., stents, drains, central venous catheters) are more often being used in the treatment of many diseases.

Abdominal Pain↗
PubMedDate not supplied

Effect of the Hanshin-Awaji earthquake on posttraumatic stress, lifestyle changes, and cortisol levels of victims.

In 1995, the Hanshin-Awaji area in Japan was damaged severely by a major earthquake. In this study, the authors administered questionnaires and obtained blood samples to analyze the relationships among lifestyle, psychological stress, and plasma cortisol levels of victims. The authors questioned 107 male inhabitants of Awaji Island about their lifestyles before and after the earthquake, presence of any symptoms of posttraumatic stress disorder, and demographic variables. Plasma cortisol levels were determined with enzyme immunoassay. Cortisol level was correlated strongly with change in lifestyle. The highest cortisol levels were found in the group characterized by a high posttraumatic stress disorder score and by a very profound lifestyle change. This group also contained the highest percentage of subjects who had poor health. In summary, the psychological stress induced by the Hanshin-Awaji earthquake was associated with mean cortisol level; however, this relationship was affected by adjustment of lifestyle.

Aged↗
PubMedDate not supplied

Brief reversible bronchospasm resulting from bichromate exposure.

A 50-y-old male worker developed an asthmatic reaction after exposure to bichromate in a metal-plating plant. Evaluation included skin tests, bronchial provocation tests, and specific radioallergosorbent tests with metal salts. A 49-y-old worker who suffered from hard metal asthma was the control. These workers were not atopic, and they exhibited similar bronchial hyperresponsiveness in methacholine-PC20 (74 mg/ml versus 81 mg/ml, respectively) and IgE titers (129 IU/ml versus 130 IU/ml). Positive intradermal and patch tests to bichromate were found in the subject. A bronchial provocation test with inhalation of .01 % bichromate produced an immediate decrease in forced vital capacity in 1 s, followed by a rapid recovery within 5 min absent any treatment. There was no reaction to cobalt (1% cobalt chloride) or to nickel (2% nickel sulfate) salts. In the control, a positive bronchial provocation occurred (absent chromium) with cobalt and nickel. Administration of a subcutaneous preparation of 1 mg atropine sulfate or of 1 puff of disodium cromoglycate or beta-stimulant reduced bronchial responsiveness to methacholine-PC20, and no asthmatic reaction occurred following inhalation of 1% bichromate. No blocking of asthmatic reaction occurred after pretreatment with beclomethasone dipropionate inhalation. Administration of propranolol, however, potentiated the acute bronchoconstriction induced by bichromate. The 50-y-old worker had evidence of IgE antibody to chromium-conjugated human serum albumin and to chromium-conjugated exchange resin. His serum selectively bound 51Cr, but antibodies specific to cobalt and nickel were absent. These results, if viewed collectively, suggest that bichromate exposure causes brief reversible bronchospasm via alteration of autonomic balance and increased vagal activation.

Antibodies↗
PubMedDate not supplied

Interplay of cigarette smoking and occupational exposure on specific immunoglobulin E antibodies to cobalt.

The results of a cross-sectional survey of an occupational population (n = 706) exposed to hard metal dust revealed distribution of specific immunoglobulin E antibodies against cobalt-conjugated serum albumin (Co-HSA). This population was segregated with respect to smoking and dust-exposure doses. Standard deviations (0.08-0.13) of Co-HSA RAST were sufficiently small (< 7%) to warrant reproducibility. Confirming evidence for 8 workers who had mean + 3 standard deviations of Co-HSA RAST indices and who had been diagnosed with occupational asthma also provided better sensitivity (8/19) and specificity (687/687) of hard metal asthma, rather than metal-induced asthma. Cobalt exposure resulted in significant increases in Co-HSA RAST indices in males, whose mean index was 1.16 +/- 0.13 in nonexposed subjects and 1.37 +/- 0.13 in exposed subjects. There was no difference, however, in the females. This difference between males and females cannot be explained by differences in ages or dust-exposure doses. Furthermore, the specific RAST indices against Co-HSA displayed a strong correlation not only to the intensity of cobalt exposure (r = .488, p < .001), but to log(total exposure doses) (r = .578, p < .001). These results suggest that Co-HSA RAST might be useful as a biological marker for the allergic etiology of hard metal asthma. Nonexposed smokers had similar mean RAST indices: 1.18 +/- 0.12 IU/ml, compared with 1.15 +/- 0.16 IU/ml for nonexposed subjects who had never smoked. There was no correlation between Brinkman indices (i.e., number of cigarettes/d x y) and RAST indices in any of the male groups. Higher, but not significant, mean RAST indices were found for ex-smokers in both the nonexposed (1.18 +/- 0.14) and exposed subjects (1.26 +/- 0.12), compared with subjects who had never smoked. Serum immunoglobulin E levels in the ex-smokers declined with age after they quit smoking, irrespective of exposure status. In contrast, hard metal (cobalt) exposure elevated specific immunoglobulin E. The results of the study suggest that elimination of hard dust exposure is more important than cessation of smoking in the minimization of risk of bronchial asthma. Hard metal exposure may be a preventable risk factor for occupational asthma.

Adult↗
PubMedDate not supplied

Usefulness of microspheres composed of gelatin with various cross-linking density.

The release rate of insulin, as a model peptide, from gelatin microspheres (GM) prepared with gelatin having various cross-linking densities in vitro was examined. The release of insulin from GM showed the burst effect, followed by a slow release phase regardless of the cross-linking density of gelatin. The total amount of insulin released in 2 weeks decreased with increasing cross-linking density of gelatin. The release rate of insulin within 6 h was well correlated with the cross-linking density of gelatin. The remaining amounts of both insulin and GM after injection of insulin incorporated in GM to mice femoral muscle tissue were also examined in vivo. Both insulin and GM rapidly disappeared from the injection site within 1 day, and thereafter slowly disappeared over 14 days. The time courses of the remaining amounts were fairly similar to each other. Furthermore, the remaining amount of insulin 1 day after administration was well correlated with the cross-linking density of gelatin. These data suggest that insulin was released from GM with the degradation of GM in mice muscular tissue and that the release rate of insulin can be controlled by modifying the cross-linking density of gelatin. In conclusion, the control of the release rate of insulin from GM can be achieved under both in vitro and in vivo conditions by gelatin through the alteration of cross-linking conditions.

Animals↗
PubMedDate not supplied

Positively charged gelatin microspheres as gastric mucoadhesive drug delivery system for eradication of H. pylori.

Gastric mucoadhesive drug delivery systems are very promising for eradication of Helicobacter pylori (H. pylori), a spiral bacterium that resides in the gastric mucus layer and at the mucus-epithelial cell interface. New positively charged biodegradable microspheres were prepared using aminated gelatin by surfactant-free emulsification in olive oil, followed by a cross-linking reaction with glutaraldehyde. The amino group contents of the modified gelatin and the microspheres were determined using a 2,4,6-trinitrobenzenesulfonic acid method. With the increase of glutaraldehyde concentration, the amino group content of the microspheres decreased accordingly. The influence of glutaraldehyde concentration, cross-linking reaction time, drug-loading patterns, and type of release media on the in vitro release characteristics of amoxicillin from the microspheres was investigated. Amoxicillin release rate from the modified gelatin microspheres was significantly reduced compared with that from gelatin microspheres. Furthermore, the release was decreased with the increase of glutaraldehyde concentration and/or cross-linking time. On the other hand, a faster release was observed in a lower pH release medium and/or using a lower pH solution for amoxicillin loading. The gastric mucoadhesive properties of the microspheres were evaluated using RITC-labeled microspheres in an isolated rat stomach. The gastric mucoadhesion of the modified gelatin microspheres was markedly improved compared with that of gelatin microspheres. The modified gelatin microsphere proves to be a possible candidate delivery system for the effective eradication of H. pylori.

Adhesives↗
PubMedDate not supplied

Tissue pressure measurements as a determinant for the need of fasciotomy.

An experimental and clinical tehcnique of measuring tissue pressures within closed compartments demonstrates a normal tissue pressure is approximately zero mmHg, and increased markedly in compartmental syndromes. There is inadequate perfusion and relative ischemia when the tissue pressure within a closed compartment rises to within 10-30 mm Hg of the patient's diastolic blood pressure. Fasciotomy is usually indicated, therefore, when the tissue pressure rises to 40-45 mm Hg in a patient with a diastolic blood pressure of 70 mm Hg and any of the signs or symptoms of a compartmental syndrome. There is no effective tissue perfusion within a closed compartment when the tissue pressure equals or exceeds the patient's diastolic blood pressure. A fasciotomy is definitely indicated in this circumstance, although distal pulses may be present. The measurement of tissue pressure aids in the early diagnosis and appropriate treatment of compartmental syndromes.

Aged↗
PubMedDate not supplied

A case of low-grade fibromyxoid sarcoma of the thigh.

A case of low-grade fibromyxoid sarcoma in the thigh of a 21 year old female is described. The patient had a fist-sized well-defined mass in her left thigh that enlarged over a 6 month period. Histologically, the neoplasm showed contrasting fibrous and myxoid areas with a swirling growth pattern. Cellularity was low to moderate, and the stromal cells were benign looking without mitoses or nuclear pleomorphism. The tissue was not noticeably vascular. Some stromal cells were aggregated around the blood vessels. The stromal cells were immunoreactive to vimentin, but were negative to keratin, desmin, alpha-smooth muscle actin, actin HHF35, S-100 protein, neuron-specific enolase, and epithelial membrane antigen. Ultrastructural examinations of the stromal cells revealed well-developed rough endoplasmic reticulum, mitochondria, pinocytotic vesicles, and numerous intermediate-sized filaments in the cytoplasm. These findings seem to indicate that the stromal cells were fibroblastic in origin. The occurrence of the tumor in a young adult, its location and its large, well defined borders together with the characteristics revealed through histological investigation, indicated that it was in fact what has been termed by Evans as a low-grade fibromyxoid sarcoma.

Adult↗
PubMedDate not supplied

The substantia nigra is an important site for the containment of seizure generalization in the kindling model of epilepsy.

To investigate the role of the substantia nigra (SN) in kindling, electrical stimulation of the SN was delivered at various times before or after stimulation of the amygdala (AM) or pyriform cortex during or after kindling in rats. The results were as follows: Ipsilateral SN stimulation delivered prior to each AM kindling stimulation for 14 days significantly retarded the appearance of Stage 4 and 5 seizures and shortened the afterdischarge (AD) duration. Bilateral SN prestimulation blocked seizure generalization in some AM- or pyriform cortex-kindled animals, prolonged the latency to bilateral forelimb clonus in others, and shortened the AD duration of the kindled seizure in a current intensity-dependent fashion. These effects were only partially antagonized by haloperidol, but were completely abolished by picrotoxin. The picrotoxin alone significantly reduced the latency. Almost no effect was found when the SN stimulation was delivered after the onset of bilateral forelimb clonus. We conclude that the SN might be an important mediator of the early aspects of seizure generalization from limbic epileptic foci. The relative involvements of GABAergic gamma-aminobutyric acid and dopaminergic systems of the SN in this inhibitory function are discussed.

Amygdala↗
PubMedDate not supplied

Increase of methylguanidine and guanidinoacetic acid in the brain of amygdala-kindled rats.

Guanidino compounds are intrinsic chemoconvulsants. We investigated the regional and time-dependent changes of these compounds in the amygdala (AM) of kindled rats versus electroconvulsive shock (ECS) seizures using high-performance liquid chromatography (HPLC). Twenty-eight days after the last AM-kindled seizure, guanidinoacetic acid (GAA) and methylguanidine (MG) levels were significantly increased in the bilateral AM as compared with those of control rats, which had been implanted with electrodes but were not stimulated. Both compounds, however, tended to decrease in the bilateral AM after ECS seizure. In addition, we measured these compounds after induction of one afterdischarge (AD) in the AM. These compounds increased significantly 7 days after AD was induced in the ipsilateral AM. We suggest that the increase of these compounds is coincident with AD generation and specific to AM kindling and the kindled state.

Amygdala↗
PubMedDate not supplied

Comparative study of the anticonvulsant effect of gamma-aminobutyric acid agonists in the feline kindling model of epilepsy.

We made a comparative study of the anticonvulsant effect of GABA agonists on feline amygdala or hippocampal kindled seizures. Progabide (PGB) [gamma-aminobutyric acid (GABA) receptor agonist 25-100 mg/kg intraperitoneally, i.p.] significantly reduced both the kindled seizure stage and after discharge (AD) duration in a dose-dependent manner. SKF89976A (GABA uptake inhibitor 0.5-2.0 mg/kg i.p.) also significantly reduced the kindled seizure stage. Toxic doses of SKF89976A caused generalized paroxysmal EEG discharges and myoclonus, but AD generation in the kindled focus was suppressed completely. Furthermore, gamma-vinyl GABA (GABA catabolic enzyme inhibitor, GVG 50-200 mg/kg i.p.) significantly reduced the seizure stage, while causing prolongation of the AD duration. In contrast, baclofen (selective GABAB receptor agonist, 1 or 5 mg/kg) did not show anticonvulsant effects on any parameters of kindled seizures. Therefore, these GABA agonists, which potentiate the inhibitory function of the GABAA systems, have potent anticonvulsant effects on partial onset and secondarily generalized limbic seizures.

Aminocaproates↗
PubMedDate not supplied

Once-daily use of ofloxacin for prophylaxis in breast cancer surgery.

The 150 consecutive patients who were hospitalized for breast cancer at our department between September 1992 and November 1995 were enrolled in this open study after having given their informed consent. Patients were assigned randomly to receive ofloxacin in daily doses of 200 mg to be taken in a single dose or a total dose of 600 mg divided into three doses postoperatively for 5 days. Ten patients (8 found to be without malignancies) were excluded from evaluation. Wound infections developed in 8 (12%) of the 69 patients in the 200-mg group and 12 (17%) of the 71 patients in the 600-mg group. Postoperative wound care lasted a median of 19 days (25th and 75th percentiles, 15 and 29 days) for patients given 200 mg and 16 days (13 and 25 days) for those given 600 mg; the difference was not statistically significant (Wilcoxon's U test). Signs or symptoms suggesting ofloxacin toxicity were not observed, and several significant differences were found in laboratory test results between the two groups both before and after treatment. Abnormal changes after treatment were found in many individuals, but the rate of occurrence was similar in the two groups (U test). When ofloxacin is used for prophylaxis after breast surgery, we recommend a once-daily administration of 200 mg orally for financial reasons and increased patient compliance.

Adult↗
PubMedDate not supplied

Maternal inheritance of atopy at the Fc epsilon RI beta locus in Japanese sibs.

Twenty-four Japanese atopic sibs with asthma and/or rhinitis were tested for polymorphic microsatellite repeats of Fc epsilon RI beta on chromosome 11q13. Significantly increased sharing of maternal alleles was found chi 2 = 5.86, p < 0.025) while no significant sharing was found for paternal alleles. These findings confirm maternal inheritance of atopy at this locus in a non-Caucasian population.

Asthma↗
PubMedDate not supplied

Studies on the activation and molecular weight of inactive renin in human plasma.

The mechanism of activation of inactive renin was studied in normal human plasma. The molecular weight of active renin and those of inactive renin before and after activation were analyzed by sephadex gel filtration. Active renin of human plasma had a molecular weight of 48,000 +/- 1000. Trypsin treatment and cold treatment activated inactive renin of a molecular weight of 54,000 +/- 1000. The inactive renin apparently did not change its molecular weight after activation. "Cryoactivation" of inactive renin was possible only when whole plasma was used. When the whole plasma was fractionated by gel filtration, cryoactivation was not observed in any of the fractions. Cryoactivation requires certain plasma factor(s) contained in some fractions. Plasma kallikrein is likely to be a major factor required for the cryoactivation of inactive renin, whereas some other factors may also participate in this mechanism.

Cold Temperature↗
PubMedDate not supplied

Activation and reinactivation of inactive renin in normal human plasma.

Various facets of activation of inactive renin by acidification or cold exposure were investigated in normal human plasma. The acid activation obtained by titration was usually less than that by dialysis method, but varied from 41% to 122% of the latter. The acid phase of acid activation accounted for about 70% of the total activation achieved by the combined effects of the acid and alkaline phases on the average, and was not affected by any of the inhibitors for serine, thiol or carboxyl protease, whereas serine protease inhibitors suppressed the activation of both renin and plasma kallikrein in the alkaline phase of acid activation. A different mode of plasma kallikrein activation suggested some difference in the mechanism between the alkaline phase of acid activation and the cryoactivation. A part of cryoactivation of renin was independent of the action of plasma kallikrein. The renin activated by either acidification or cold exposure without concomitant activation of plasma kallikrein was reinactivated by the removal of pH and temperature, but recovered by repeating acidification or cold exposure. When active plasma kallikrein had been produced, it activated inactive renin irreversibly. It appears unlikely that irreversible activation of inactive renin is taking place in the normal circulation where practically no active plasma kallikrein is present.

Acid-Base Equilibrium↗