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Biomedical subjects

H Sakai

Publications and source records attributed to H Sakai.

At least 541 records · Page 30Linked to original sources
PubMed1996

[Two cases of liver scar that was examined by biliary scintigraphy].

36-year-old-female admitted because of jaudice and ascites. T-bil was 18.5 mg/dl and transaminase, ALP, LDH and gamma-GTP was elevated. Ultrasonography (US) showed that right lobe was atrophy and left lobe was swelling. Plain computed tomography (CT) showed right lobe was low density. Magnetic resonance (MR) finding was T1-weighted image of right lobe was low intensity and T2-weighted image was high intensity. Angiography showed right lobe was more stained than left lobe. Histologically, right lobe was massive necrosis. These findings suggested that right lobe was liver scar. Biliary imaging showed right lobe was delayed. A 23-year-old-female admitted because of fever and abdominal tumor. Transaminase was normal, only gamma-GTP was elevated. US, plain CT, enhanced CT, MR imaging finding was as same as that of the first case. Similarily, biliary scintigraphy showed right lobe was delayed. Causes of the two liver scars was not clear, whereas liver scar detected after delivery was rare case.

Adult↗
PubMed1996

[Anesthetic problems in a 480 g infant for ventriculo-peritoneal shunt surgery].

A 480 g, 38-day-old female infant underwent ventriculo-peritoneal shunt surgery for hydrocephalus after intra-ventricular hemorrhage. The patient was born at a gestational age of 25 weeks and 5 days, weighing 600 g, as one of twins by a cesarean section. Although respiratory distress syndrome developed, it was relieved with surfactant. The esophagus was easily perforated by a gastric tube. At the age of 7 days, PDA was closed conservatively with indomethacin. Anesthesia was induced and maintained with fentanyl (induction dose 4 micrograms.kg-1, total dose 6 micrograms.kg-1) and vecuronium. Ventilation was controlled with oxygen and air (FIO2 0.21-0.25). The main problems encountered by anesthetists in the perioperative period were; fluid management (hyperkalemia, hyponatremia, infusion volume), bradycardia due to increased intracranial pressure, body temperature control (hypothermia), and transport to the operating room. In anesthesia for extremely low birth weight (extremely premature) infants, utmost care and proficient procedure are required because of their immaturity, fragility and smallness.

Adjuvants, Anesthesia↗
PubMed1996

Comparison of serodiagnostic tests and ultrasonography for cystic hydatidosis in an epidemiological study of rural Uruguay.

Cystic hydatidosis (CH) caused by Echinococcus granulosus is an important zoonosis worldwide. Several serodiagnostic and ultrasound tests are currently used for screening asymptomatic CH. The sensitivity of the serodiagnostic tests has been demonstrated by several groups to be lower than ultrasonography (US). To explain the mechanism of the difference in sensitivity, a large-scale US survey combined with an IgG4-enzyme-linked immunosorbent assay test was conducted in Uruguay. Our results suggest that certain cyst images, e.g., multivesicular cysts, may be closely associated with a high antibody response regardless of the cyst size, whereas other hydatid lesions, e.g., solid images with/without rolled parasite membranes, have lower antibody responses with a close relationship to cyst size. Seropositivity of subjects who had been treated surgically for removal of hydatid cysts in the last 5 yr was closest to that of actual CH patients, albeit free from CH by US. These findings are important for the proper use of serodiagnostic tests and US for community-based epidemiological studies.

Animals↗
PubMed1996

Analysis of the structure and expression of the augmenter of liver regeneration (ALR) gene.

BACKGROUND: The gene encoding the hepatotrophic factor Augmenter of Liver Regeneration (ALR) has recently been cloned in the rat. The availability of the mouse form of ALR would allow the analysis of the role of this factor in the physiology of liver and other organs, while the identification of the human homolog would allow the transfer of the great wealth of information that has been generated in animal models to clinically oriented pilot trials, and eventually the therapeutic application of this information. MATERIALS AND METHODS: Standard molecular biology approaches have been used to determine the genomic structure of the ALR gene in the mouse, and to characterize the ALR transcript and its protein product. The human ALR cDNA was also isolated and the amino acid sequence of the human gene product deduced. The mapping of mouse and human ALR genes on mouse and human chromosomes was then completed. RESULTS: The protein coding portion of the mouse ALR gene is comprised of three exons, the first containing the 5' untranslated sequence and the initial 18 bases after the ATG translation initiation codon, the second exon encompasses 198 bases, and the third exon contains the remaining portion of the protein coding sequence. Rat, mouse, and human ALR genes (and protein products) were found to be highly conserved and preferentially expressed in the testis and in the liver. The ALR gene maps to the mouse chromosome 17, in a region syntenic with human chromosome 16, where the T/t region has also been mapped. CONCLUSIONS: ALR appears to be a protein with important physiologic properties, not exclusively limited to liver regeneration, with roles that are involved in the synthesis or stability of the nuclear and mitochondrial transcripts that are present in actively regenerating cells, particularly the germ cells of the testes.

Amino Acid Sequence↗
PubMed1996

Ring chromosome 15 syndrome in an adult female.

In this paper, the authors present the case of a 24-year-old female with ring 15 chromosome syndrome. Upon examination, the patient presented with severe mental retardation, dwarfism and microcephaly, along with other minor dysmorphic stigmata. We compared this case with three other adult female cases with this chromosomal aberration. As a result, the authors observed a somewhat dysharmonious profile between the level of mental retardation and behavioural findings in the four women, while sexual development and gonadal function seemed to be normal in all four cases.

Adult↗
PubMed1996

[Clinical study of serum antibodies specific to Chlamydia trachomatis in patients with chronic nonbacterial prostatitis and prostatodynia].

The etiological role of Chlamydia trachomatis in chronic nonbacterial prostatitis is controversial. To assess whether C. trachomatis relates to chronic nonbacterial prostatitis, we investigated the serum levels of immunoglobulin G (IgG) and IgA antibodies specific for C. trachomatis in 41 patients with chronic nonbacterial prostatitis and 47 patients with prostatodynia. The positive rates of the IgG antibody were 29% and 28% in patients with chronic nonbacterial prostatitis and prostatodynia, respectively. There was little difference in the positive rates of the IgG and IgA antibodies for C. trachomatis, between patients with chronic nonbacterial prostatitis and prostatodynia. Also, there was no significant difference in the positive rate of the IgG antibody between 51 patients complaining of urinary symptoms and 25 complaining of referred pain. However, a high positive rate of the IgG antibody (80%) was observed in patients with hematospermia. Our findings suggest that C. trachomatis could not be etiologically responsible for chronic nonbacterial prostatitis, but that it may be related to hematospermia.

Adult↗
PubMed1996

[Gastrointestinal metastasis from lung cancer].

Metastasis of lung cancer to the digestive tract (excluding the esophagus) was confirmed by surgery or autopsy in 30 of the 1635 lung-cancer patients admitted to this Center during the 17-year period since 1977. The diagnosis was made before death in 7 and after death in 23. Metastasis of large cell carcinoma was the most common (3.7%), followed by adenocarcinoma (2.4%), small cell carcinoma (1.7%), and squamous cell carcinoma (0.7%). Metastasis to the stomach occurred in 0.4%, to the small intestine in 1.1% and to the colon in 0.5%. The overall percentage of metastasis to the digestive tract was 1.8%. Among the 298 cases diagnosed at autopsy, metastasis to the digestive tract occurred in 9.7%; stomach, 2.6%; small intestine, 5.7%; and colon, 3.0%. Eleven of the patients in whom the diagnosis was made at autopsy had abdominal symptoms while they were alive. In 11 cases diagnosed at autopsy, occult blood was positive in 9, but 6 of those 9 patients were asymptomatic. The occult-blood test is considered to be helpful as a supplementary diagnostic method in detecting metastasis of lung cancer to the digestive tract. Among the cases diagnosed while the patients were alive, metastasis was observed in the small intestine in 6 and in the colon in 1. The major manifestations were melena, ileus, intussusception, and perforation; 4 patients required emergency surgery. The prognosis was poor: the mean survival period from the onset of symptoms was 49 days. The direct cause of death was metastasis to the digestive tract in 5 cases. The possibility of metastasis to the digestive tract is high when progressive abdominal symptoms are observed and the stool is persistently positive on occult-blood tests.

Adenocarcinoma↗
PubMed1996

[Photodynamic therapy for early stage lung cancer].

Since 1980, 225 patients with lung cancers have been treated with photodynamic therapy (PDT) at Tokyo Medical College. These were 212 males and 13 females, and the median age was 65.2 years (range 36 to 85). Clinical stages were 72 early stage, 33 stage I, 11 stage II, 84 stage III and 25 stage IV. In 72 cases (91 lesions) of early stage lung cancers, complete remissions were obtained in 75 cases (82.4%) and partial remission in 16 cases. Mean survival after PDT was 52 months and 53 cases were disease free in 5 to 176 months. PDT is useful in the treatment for early stage lung cancer.

Adult↗
PubMed1996

Leukemic transformation in three patients with polycythemia vera. Analysis of the clinicopathological features and N-ras gene mutation.

Thirty-three patients were diagnosed as having polycythemia vera (PV) from 1973 to 1993 in our institution. Of these patients, three who had been treated with alkylating agents, progressed to acute non-lymphocytic leukemia (ANLL). Their physical findings and the laboratory data were similar to those patients who did not become leukemic. To investigate the association with leukemic evolution, we examined N-ras oncogene activation in those patients who progressed to acute leukemia. Point mutations in codons 12 and 13 were not always detected, suggesting that the N-ras gene did not influence occurrence of ANLL in our patients.

Adult↗
PubMed1996

Membrane currents of murine osteoclasts generated from bone marrow/stromal cell co-culture.

Whole cell clamp recordings were conducted to examine the general behavior of ion channels in osteoclasts which were generated from bone marrow/stromal cell co-culture. In the resting state, inwardly and outwardly rectifying (IR and OR) currents were observed in the osteoclasts cultured for 5-18 days and the whole cell currents were classified into three types according to the conductance ratio between the OR and IR currents, such as, the IR type (OR/IR conductance < or = 0.2), the IR-OR type (0.2 < OR/IR < or = 5), and the OR type (OR/IR > 5). The IR type was found in 73% of cells (n = 78), the IR-OR type in 26% and the OR type in 1%. No relation was found between the current types and the number of nuclei or cultured days. The conductances varied among cells, but the IR conductance was larger than the OR conductance. The IR current was characterized by voltage-dependent kinetics, a negative conductance region and Ba(2+)-sensitivity. The reversal potential depended on the extracellular K+ concentration, indicating that K+ mediates the IR current. On the other hand, the OR current was reversibly reduced by decreasing extracellular Cl- concentration but not affected by K+, suggesting that the OR current depends on Cl-. High intracellular Ca2+ (1-10 microM) transiently activated a different class of outward current. These electrophysiological features resemble those in freshly isolated osteoclasts. We suggest that the ion channels involved in osteoclastic functions are expressed in the in vitro-generated osteoclasts and that the channels develop early in differentiation and are maintained for at least up to 18 days. Thus the co-culture system provide a useful model to examine roles of ion channels in osteoclastic functions.

Animals↗
PubMed1996

[Laser photodynamic therapy for central-type lung cancer].

Laser endoscopic surgery is recognized as an effective treatment for lung cancer. Attention has increasingly been focused on photodynamic therapy (PDT) with dihermatoporphyrin ethers. The Japanese government approved the use of this therapy in October 1995, and reimbursement through the national health insurance system began in April 1996. Over the past decade, 140 patients (283 lesions) with central type lung cancers have been treated at our hospital. Overall complete remission was obtained in 39.6% of 112 lesions, partial remission in 59.4% and no remission in 1.0% The indications for PDT are as follows: 1. Early stage lung cancer curative; among 95 early stage lesions complete remission was obtained in 79 (83.2%), and 71 patients were disease free at 3 to 176 months. 2. Advanced lesions opening of bronchi; overall, "effective" opening of bronchi was achieved in 61 of 81 lesions (75%), in the PDT group, and in 143 of 177 (81%) in the Nd-YAG laser therapy groups. 3. Preoperative laser irradiation to increase operability and reduce the extent of operation; the extent of resectin was reduced, or inoperable lesions were made operable in 21 of 24 patients treated. 4. Multiple primary lung cancer. The success of clinical trials of PDT for treatment of lung cancers bodes well for its future use. More stable, definitive, and successful treatment will become possible with the use of new dyes that distribute more evenly in tumor tissue, and with the deeper tissue penetration made possible by longer-wavelength beams.

Adenocarcinoma↗
PubMed1995

Fas receptor (CD95)-mediated apoptosis is induced in leukemic cells entering G1B compartment of the cell cycle.

Apoptotic cell death induced by cross-linking Fas receptor (FasR/CD95) has been investigated in human acute myelogenous leukemia (AML) cells. FasR-mediated growth inhibition and DNA fragmentation could be induced in certain cases of AML. Interestingly, when DNA synthesis and G1 -> S transition in the cell cycle were enhanced by interleukin-3 or granulocyte-macrophage colony-stimulating factor, Fas-insensitive blast cells acquired cellular susceptibility toward FasR-mediated growth inhibition. To further evaluate an association between the Fas-R-mediated action and a specific phase of the cell cycle, a FasR+ leukemic cell line, MML-1, was established from a patient with AML. The morphologic feature of dying cells and DNA fragmentation indicated that FasR cross-linking induced apoptotic cell death in MML-1 cells. Cell cycle arrest in G1A phase with the treatment of phorbol 12-myristate 13-acetate or thymidine rendered MML-1 cells resistant to FasR-mediated apoptosis without downregulation of surface FasR expression. However, S-phase arrest with 5-fluorouracil could neither enhance nor inhibit FasR-mediated apoptosis. Simultaneous DNA/RNA quantification analysis revealed the selective loss of cells in G1B compartment, accompanied by the increase of apoptotic nuclei in sub-G1 fraction. These findings suggested that FasR-mediated apoptotic signals could be transduced into cells in G1B compartment and G1A -> G1B transition might augment the induction of FasR-mediated apoptosis.

Acute Disease↗
PubMed1995

Role of SUPERMAN in maintaining Arabidopsis floral whorl boundaries.

The Arabidopsis gene SUPERMAN (SUP) is necessary for the proper spatial development of reproductive floral tissues. Recessive mutations cause extra stamens to form interior to the normal third whorl stamens, at the expense of fourth whorl carpel development. The mutant phenotype is associated with the ectopic expression of the B function genes, AP3 and PI, in the altered floral region, closer to the centre of the flower than in the wild type, and ap3 sup and pi sup double mutants exhibit a phenotype similar to ap3 and pi single mutants. These findings led to SUP being interpreted as an upstream negative regulator of the B function organ-identity genes, acting in the fourth whorl, to establish a boundary between stamen and carpel whorls. Here we show, using molecular cloning and analysis, that it is expressed in the third whorl and acts to maintain this boundary in developing flowers. The putative SUPERMAN protein contains one zinc-finger and a region resembling a basic leucine zipper motif, suggesting a function in transcriptional regulation.

Amino Acid Sequence↗
PubMed1995

Ca(2+)-activated outward-rectifier K+ channels and histamine release by rat gastric enterochromaffin-like cells.

Gastric enterochromaffin-like (ECL) cells were isolated from rat gastric fundic mucosa by Percoll density-gradient centrifugation and counter-flow elutriation. About 67% of cells in the purified cell suspension were ECL cells, which were reacted with anti-histidine decarboxylase antibody. A23187, a calcium ionophore, at 0.1-10 microM induced histamine release from ECL cell-rich suspension, indicating that the Ca2+ pathway is involved in the mechanism of histamine release from the ECL cells. A23187 at 5 microM significantly increased outward-rectifier cationic current in 62% of cells in the ECL cell-rich factions. A23187-sensitive cells showed acridine orange uptake. In single-channel recordings, a Ca(2+)-dependent outward-rectifier K+ channel of large conductance (146 +/- 22 picosiemens) was found in the cell that showed acridine orange uptake. The channel opened in a voltage-dependent manner at 0.1 microM of intracellular free Ca2+ concentration. These results may suggest that opening of the Ca(2+)-activated K+ channel is one of the steps involved in the mechanism of histamine release in ECL cells.

Animals↗
PubMed1995

Comparison of primary structures and substrate specificities of two pullulan-hydrolyzing alpha-amylases, TVA I and TVA II, from Thermoactinomyces vulgaris R-47.

Thermoactinomyces vulgaris R-47 produces two alpha-amylases, TVA I, an extracellular enzyme, and TVA II, an intracellular enzyme. Both enzymes hydrolyze pullulan to produce panose, and also hydrolyze cyclodextrins. We cloned and sequenced the TVA I gene. The TVA I gene consisted of 1833 base pairs, and the deduced primary structure was composed of 611 amino-acid residues, including an N-terminal signal sequence consisting of 29 amino-acid residues. The similarity between the amino-acid sequence of mature TVA I with those of other pullulan/cyclodextrin-hydrolyzing enzymes, such as TVA II and Bacillus stearothermophilus neopullulanase, was only 30%, although that of TVA II with neopullulanase was 48%. TVA II prefers specific small oligosaccharides and alpha- and beta-cyclodextrins. Whereas kcat/Km values of TVA I for pullulan were larger than that of TVA II, and TVA II could not hydrolyze starch completely. TVA II was inhibited by maltose, the hydrolysate of starch, which seems to be the reason for inefficient hydrolysis of starch. These kinetic properties indicate that TVA I and TVA II have differential physiological roles in sugar metabolism extracellularly and intracellularly, respectively.

Amino Acid Sequence↗
PubMed1995

Generation and characterization of a host cell-dependent gag gene mutant of human immunodeficiency virus type 1.

An in-frame gag gene mutant of human immunodeficiency virus type 1, which carries two amino acid substitutions in the center of the p24 coding region, was constructed in vitro, and its replication properties in several cell lines were examined. In CD4-negative SW480 cells transfected with the mutant clone, synthesis and processing of viral gag, pol, and env proteins occurred normally, and viral particles were produced. Virions derived from the transfection displayed a severe replication defect when inoculated into some CD4-positive cell lines (H9 and Molt4 clone 8), but in other lines (A3.01 and M8166), the mutant virus grew fairly well. The mutant was demonstrated to be defective at an early infection phase (from adsorption to integration) in Molt4 clone 8 cells but was normal in A3.01 cells. These results indicated that the Gag-p24 protein of human immunodeficiency virus type 1 plays an important role at the early infection phase in a cell-dependent manner.

Amino Acid Sequence↗
PubMed1995

The interaction of RepC initiator with iterons in the replication of the broad host-range plasmid RSF1010.

The replication origin of the broad host-range plasmid RSF1010 contains 3.5 copies of a 20mer iteron sequence that bind specifically to the plasmid-encoded initiator, RepC. Here we demonstrated that even a single iteron was bent upon binding of RepC. Moreover, the bending angle seems to become larger along with the increment of the number of iterons. In a mutational analysis of the iteron sequence, we isolated seven kinds of base-substitution mutants of iterons, and estimated the replication activity of these mutants in vivo. We found that each of the subsections in the 20mer iteron sequence made a distinct contribution to the initiation of RSF1010 DNA replication. With the binding assay of RepC and mutated iterons in vitro, we found that the formation of a productive RepC-iteron complex was required for the initiation of plasmid DNA replication.

Bacterial Proteins↗