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Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 541 records · Page 30Linked to original sources
PubMed1995

The appearance of male gamete-specific histones gH2B and gH3 during pollen development in Lilium longiflorum.

The male gametic (generative) nucleus within the nearly mature pollen of Lilium longiflorum contains specific variants of histone H2B and H3, which have been designated gH2B and gH3, respectively. Using specific antibodies raised against gH2B and gH3, we examined in detail the temporal and spatial aspects of the appearance of these histone variants during male gametogenesis. Neither gH2B nor gH3 was detected in microsporocytes during meiotic division or in microspores before microspore mitosis. However, both gH2B and gH3 were abundantly present in mid bicellular pollen and these histones continued to be detectable in germinated pollen tubes after pollination. Furthermore, immunocytochemistry revealed that these proteins were present not only in generative nuclei during the maturation process, but also in the two sperm nuclei formed by division of the generative nucleus. By contrast, these proteins were not found in the vegetative nuclei. It appears, therefore, that both gH2B and gH3 are specific to male gametic (generative and sperm) nuclei in L. longiflorum. The results also suggest that these male gamete-specific histones might be newly synthesized in the progenitor of sperm cells for the differentiation of male gametes, as occurs in spermatogenesis in animals.

Cell Differentiation↗
PubMed1995

Molecular cloning and expression in Escherichia coli of bleomycin-resistance gene from a methicillin-resistant Staphylococcus aureus and its association with IS431 mec.

A gene that confers bleomycin resistance was cloned from the chromosomal DNA of methicillin-resistant Staphylococcus aureus (MRSA) B-26 into the plasmid pUC18. It is of chromosomal origin rather than plasmid and exists in the chromosome making a cluster with the kanamycin-resistance gene. We found that the nucleotide sequence of the bleomycin-resistance gene from the chromosome of MRSA B-26 is identical to that from a staphylococcal plasmid, pUB110. The partial sequence of IS431mec was also found upstream from the DNA fragment containing the bleomycin- and kanamycin-resistance genes.

Base Sequence↗
PubMed1995

Doxorubicin-heparin complex: reduction of cardiotoxicity of doxorubicin.

We have compared the antitumor activity and cardiotoxicity of free doxorubicin (Dox) and doxorubicin-heparin complex in vivo and in vitro. Dox and Dox-heparin complex equally inhibited the DNA synthesis of leukemic cells and showed a similar anticancer activity against tumor-bearing mice. Acute toxicity of Dox at the dose of 20 mg/kg or 30 mg/kg was significantly more profound than that of the Dox-heparin complex, which was demonstrated by survival rate (P < 0.01). Chronic toxicities of Dox and the Dox-heparin complex were compared by giving the respective reagent (2 mg/kg) weekly for 20 weeks. The weight gains of the mice given Dox-heparin complex were greater than those of the mice given Dox alone (P < 0.01). The pathological damage to the cardiac tissue in mice treated with Dox-heparin complex was significantly less severe than that of mice treated with Dox. Thus, the present study indicates that complexing with heparin diminished the acute and chronic toxicity of Dox without reducing its antitumor activity in mice, and suggests a possible clinical application of Dox-heparin complex in humans.

Animals↗
PubMed1995

Patent ductus venosus associated with a hyperintense globus pallidum on T1-weighted magnetic resonance imaging and pulmonary hypertension.

UNLABELLED: We report the case of a 13-year-old Japanese boy with a patent ductus venosus. He experienced mild disorientation and hallucination at age 8 years. Hyperammonaemia was discovered at age 12 years. Brain MRI demonstrated multiple intracranial hyperintense lesions, mainly in the globus pallidum, which suggested portosystemic encephalopathy. Patent ductus venosus was demonstrated by abdominal ultrasonography and angiography. Cardiopulmonary investigation revealed pulmonary hypertension. An intracranial hyperintense lesion observed on T1-weighted MRI may be an initial clue for discovering a patent ductus venosus in asymptomatic patients. CONCLUSION: When patent ductus venosus is disclosed, pulmonary hypertension should be sought, as in cases with other portosystemic shunts.

Adolescent↗
PubMed1995

Histiocytic haemophagocytosis in a patient with Kawasaki disease: changes in the hypercytokinaemic state.

UNLABELLED: A 32-month-old Japanese boy exhibited haemophagocytic syndrome (HPS) during the recurrent course of Kawasaki disease. Despite repeated gamma-globulin therapy, he developed cytopenia with marked hepatomegaly and evidence of histiocytic haemophagocytosis in the bone marrow. Serum levels of interferon-gamma and tumour necrosis factor, but not of interleukin-1 beta, increased in parallel with his symptoms. No confirmation was obtained of the association of toxic reactions to the used drugs. No coronary lesions remained as sequelae. CONCLUSION: Cytopenia in Kawasaki disease could herald HPS, and the hypercytokinaemia involved in the two febrile syndromes might be of distinct nature.

Child, Preschool↗
PubMed1995

Identification of apoptotic hepatocytes in situ in rat liver after lead nitrate administration.

Apoptosis plays a major role in the regression of mitogen (lead nitrate)-induced hepatic hyperplasia. We compared the in situ end-labeling (ISEL) technique with the conventional detection of apoptotic bodies in this process. In hematoxylin and eosin (H&E) sections, apoptosis is usually recognizable by the presence of apoptotic bodies (apoptosis phase 2). Although the early phase of apoptosis (apoptosis phase 1) can be detected as a prekaryorrhectic appearance in H&E sections, it is difficult to detect and is easily overlooked. On the other hand, ISEL presents intense staining mainly in phase 1 and weak or negative staining in phase 2. Thus, simultaneous investigation by these two methods in two serial sections is the most reliable way to calculate the incidence of apoptosis and gives us precise information on the stages of apoptosis in situ. Since the colorized signals of ISEL are much easier to detect than apoptotic bodies in H&E sections, ISEL is particularly useful for liver tissues, where the incidence of apoptosis is low.

Animals↗
PubMed1995

Neuroblastoma in infants aged less than 6 months: is more aggressive treatment necessary? A report from the Pediatric Oncology Study Group of the Kyushu area.

Infants with neuroblastoma are known to have a better prognosis than older children. In Japan in 1985, mass screening for neuroblastoma in infants aged 6 months was introduced. With this policy, there has been an increase in the number of patients seen with neuroblastoma between 6 and 11 months of age. In a previous report the authors described the management and prognosis of infants with disease detected by mass screening, but there is still little information regarding the strategies of management for infants with neuroblastoma aged less than 6 months. The authors analyzed the data regarding 27 patients aged less than 6 months registered in their region (population 15 million) from 1985 to 1992, and compared it with that of the previous 8-year period. In the younger age group, there was a significantly higher rate of advanced disease stages (III and IV). In spite of the variation in treatment related to the choice of individual institutions, infants with stages I, II, and III disease had a good outcome, suggesting that aggressive chemotherapy is not necessary unless poor prognostic factors are present. One patient with stage IV disease died of disseminated disease and one with stage IVs and 22 copies of N-myc oncogene also died of tumor relapse in spite of aggressive chemotherapy. It is therefore concluded that the prognosis in infants with stage IV and IVs neuroblastoma under the age of 6 months is not as good as had previously been believed, and that such patients, therefore, require special consideration.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Cell differentiation induced by poly(ADP-ribose) synthetase inhibitors.

From a survey of about 400 compounds, we found a number of potent and specific inhibitors of poly(ADP-ribose) synthetase. Two new classes of inhibitors include vesnarinones and heterocyclic amines. Although the inhibitory activity was not very strong, several of these classes of inhibitors proved to induce most efficiently differentiation of murine teratocarcinoma EC cells in culture; for example, 70 microM benzylvesnarinone or 1 mM PhIP effected almost complete change in cell morphology in 5 to 7 days. Analyses of poly(ADP-ribose) synthesis and NAD concentrations in EC cells after treatment with a differentiation inducer suggested that poly(ADP-ribose) might play a role at an initiation stage of cell differentiation.

Animals↗
PubMed1995

Immunohistochemical study of myelination and oligodendrocyte in infants with periventricular leukomalacia.

Eighteen patients with periventricular leukomalacia (PVL) of the focal or widespread type were immunohistochemically studied with respect to myelination and ferritin-containing oligodendrocytes and compared with 23 controls. Morphometric examination of myelination and ferritin-containing oligodendrocytes revealed normal development in the nonnecrotic cerebral white matter of the focal PVL brains. Myelination was mainly impaired in the necrotic or gliotic periventricular white matter of the widespread PVL brains. The expression of lipid components was poorer than that of myelin basic protein and the number of ferritin-containing oligodendrocytes was decreased in the necrotic or diffuse gliotic region of the widespread PVL brains compared to the controls. There was a significant relationship between the number of ferritin-containing oligodendrocytes and the degree of myelination. The impaired myelination in the PVL brains occurred in the necrotic as well as gliotic regions in the cerebral white matter, and may be related to the decrease of normal oligodendrocytes.

Female↗
PubMed1995

Subclinical renal oxalosis in wild-caught Japanese macaques (Macaca fuscata).

Various degrees of crystal deposition were found in the kidneys of 12 out of 59 Japanese macaques (Macaca fuscata) caught in the wild in Gifu, Japan. The needle- or rod-shaped crystals, which were radially arranged and occurred in the lumen and epithelium of the renal (mainly the proximal) tubules, were birefringent under polarized light. They stained with alizarin red S at a pH of 7.0 but not 4.2, and were identified as calcium oxalate. The morphological features of the renal lesions were similar to those previously reported in oxalate poisoning, and it was believed that the macaques ingested the oxalate in plants.

Animals↗
PubMed1995

Internal potassium shift in premature infants: cause of nonoliguric hyperkalemia.

To study the pathophysiology of nonoliguric hyperkalemia, we measured serum potassium concentration and external K balance (intake and excretion), and estimated internal K balance (a shift from intracellular space to extracellular space) in 24 nonoliguric premature infants during the first 72 hours after birth. Data were analyzed from two aspects: gestational age (group 1, 24 to 28 weeks, n = 9; group 2, 29 to 32 weeks, n = 9; group 3, 33 to 36 weeks, n = 6) and postnatal age (0 to 72 hours). Serum K concentration rose from baseline (0 hour) to 24 hours in groups 1 and 2 (p < 0.01) but did not rise in group 3. The external K balance was negative in all groups during the study period, and was more negative in the more premature infants (group 1 > group 2 > group 3) during the second 24 hours. There was a significant difference (p < 0.01) between the internal K balance of the three groups during the first 24 hours (group 1 > group 2 > group 3), and the K shift decreased significantly (p < 0.05) during the study period in groups 1 and 2. The more premature the infants, the larger the K shift and the larger the rise in serum K concentration during the first 24 hours, and the more negative the external K balance after 24 hours. These data indicate that K loading caused by the K shift associated with prematurity produces a rapid rise in serum K concentration, resulting in an increase in urinary K excretion. We conclude that an internal K shift inversely proportional to gestational and postnatal age is the primary cause of nonoliguric hyperkalemia in very premature infants.

Extracellular Space↗
PubMed1995

Echovirus type 9 epidemic in Kagoshima, southern Japan: seroepidemiology and clinical observation of aseptic meningitis.

An outbreak of aseptic meningitis caused by echovirus type 9 occurred between March and October, 1990, in Kagoshima, Southern Japan. Clinical manifestations and laboratory data of 259 children with aseptic meningitis who were admitted to the outpatient clinic of pediatrics in the Kagoshima City Hospital were analyzed (other diseases caused by echovirus type 9 were not investigated). The patients' age ranged from 1 month to 15 years and the highest incidence was in 4-year-old children. The male:female ratio was 1.3:1. Frequencies of headache (69%), vomiting (64%), neck stiffness (36%) and rash (195%) were lower than those in the previous reports in the United States or in the Europe. Pleocytosis in the cerebrospinal fluid increased with increasing age in the younger children. A predominance of neutrophils in cerebrospinal fluid lasted for 3 days or more after onset in 16% of the patients. Seroepidemiologic study suggested that the accumulation of susceptible children < 5 years of age had predisposed to the epidemic.

Adolescent↗
PubMed1995

Electromyographic study of functional recovery of free vascularized muscles grafted to the face.

The functional recovery of gracilis muscles grafted for treatment of facial paralysis in combination with a cross-face nerve graft was evaluated on the basis of electromyography in 98 cases. Initial action potentials were recorded, on average, 8 months after transplantation. There was a tendency for such potentials to appear earlier in the case of patients who finally attained good muscle activity. Action potentials were polyphasic in the early stage and of short duration and low amplitude. An increase in the amplitude and duration of potentials and a shortening of the distal latency were observed with increase in the numbers of reinnervated muscle fibers. Thereafter, there was a tendency toward decreases in the duration and number of spikes due to the increasing similarity in the distal latency of each neuromuscular unit. The grafted gracilis muscles attained a stable state about 1 year after the initial recording of action potentials. It was expected that spontaneous action potentials during rest might serve to indicate the condition of reinnervation. Their absence during the first few months after transplantation may suggest necrosis of the grafted muscle, while those of long duration and high amplitude observed after 1 postoperative year may be suggestive of disturbance in the reinnervation process. In this study, we could not find any significant difference in the reinnervation process between that of a gracilis muscle grafted following a cross-face nerve graft and a muscle reinnervated following nerve transection and repair. We therefore believe that free gracilis muscle transplantation combining a cross-face nerve graft is appropriate for the reconstruction of muscle function.

Action Potentials↗
PubMed1995

Versatility of a cross-leg free rectus abdominis flap for leg reconstruction under difficult and unfavorable conditions.

A cross-leg free rectus abdominis flap, anastomosing to utilized "carrier" vessels of the contralateral noninjured leg, was used for reconstruction in six cases of extensive traumatic defects and deformities of a lower extremity. This method provides great advantages in free-flap reconstruction of complicated and unfavorable cases in which utilization of what would be suitable recipient vessels in the injured leg is most difficult, but there is good blood circulation of the leg.

Adult↗