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Biomedical subjects

Y Kai

Publications and source records attributed to Y Kai.

At least 163 records · Page 9Linked to original sources
PubMed1989

[Intra-arterial infusion chemotherapy in non-resectable pancreatic cancer using angiotensin-II and implantable drug delivery system].

Over the past 6 years, we have treated 25 cases of pancreatic cancer, 6 cases of cholangioma in pancreas-head and 3 cases of cancer in duodenal papilla (2 cases Stage I, 5 cases stage II, 2 cases stage III, 25 cases stage IV). Twelve cases (10 unresectable cases, 1 hepatic metastasis case, 1 recurrent case) were treated with intra-arterial infusion chemotherapy using implantable Drug Delivery System, combined with angiotensin-II to increase the concentration of anti-cancer agents in cancer tissue. Twenty-four cases (70%) died in less than one year, so operation is not effective except for curative resection of cholangioma and duodenal papilla cancer. But exploratory laparotomy or inoperable cases given intermittent transcatheter arterial infusion chemotherapy (5-FU + ADM + MMC + angiotensin-II), showed favorable results (decrease of tumor size and pain in 2 cases; recanalization of obstruction in choledochus of 1 case). Especially trans-femoral or left subclavian arterial catheterization proved to be effective therapy for possibly giant or recurrent inoperable pancreatic cancer and hepatic metastasis. Using the drug delivery system, the technical approach to arterial infusion therapy and angiography has been readily undertaken. Quality of life has been improved, and course observation of the patient has been possible by imaging diagnosis and multidisciplinary treatment for advanced pancreatic cancer.

Adenoma, Bile Duct↗
PubMed1989

[Prophylactic effect of fosfomycin on CDDP nephrotoxicity].

From 1985 to 1986, cisplatin (CDDP) therapy was performed 61 times in 24 patients with urological cancer. Thirty nine courses used fosfomycin (FOM) 4 g/day from the day before CDDP administration to the last dose of CDDP, and we statistically evaluated the prophylactic effect of FOM on CDDP nephrotoxicity using urinary NAG and FENa as parameters (t-test). In the 1-day CDDP group (CDDP 60-70 mg/m2 x 1 day) with FOM a peak NAG was seen on the 1st day but no significant NAG change, FENa has a peak on the 1st day, no significant increase between the previous and the 1st day, but a significant decrease was seen between the 3rd and the 5th day (p less than 0.05). In the 5-day CDDP group (CDDP 20 mg/m2 x 5 day) NAG reached a peak level on the 5th day with FOM, showed significant increase (p less than 0.05; between the previous and the 5th day) and decrease (p less than 0.01; between the 6th and the 14th), compared to those without FOM. FENa change tended to be similar, showing a significant increase, (p less than 0.05; between the 2nd and 4th) and decrease (p less than 0.05; between the 4th and 7th) with FOM but no significant change without FOM. NAG changes with FOM were classified by pre-CDDP dose creatinine clearance (Ccr, ml/min) into 3 groups (under 50, 50-100, over 100). In the 1-day CDDP group with any Ccr no significant NAG change obtained, but, in the 5-day CDDP group with 50-100 Ccr seen a NAG peak on the 6th day, significant increase (p less than 0.05; between the previous and the 6th) and decrease (p less than 0.05; between 6th and 12th). With over 100 Ccr NAG has 4th day peak, significant increase (p less than 0.05; between the previous and the 4th), and decrease (p less than 0.05; between 4th and 8th). A prophylactic effect of FOM on CDDP nephrotoxicity was found in the 5-day CDDP group not in the 1-day CDDP group, using urinary NAG and FENa. PVB and single CDDP regimen (5 day CDDP group) with FOM can be performed safely, if the pre-CDDP dose Ccr is over 50.

Acetylglucosaminidase↗
PubMed1988

Responses of rat lateral hypothalamic neurons to periaqueductal gray stimulation and nociceptive stimuli.

The effects of dorsal periaqueductal gray (D-PAG) stimulation and noxious stimuli on neural activity in the lateral hypothalamic area (LHA) were investigated in 56 adult male anesthetized rats. Strong tail pinch was used as noxious stimulation. We examined 234 extracellular and 75 intracellular recordings of LHA responses to electrical stimulation of D-PAG. To determine neurotransmitter candidates, the effects of the opioid agonist, morphine, and its antagonist, naloxone were investigated by systemic administration and microelectrophoresis. Of 234 spontaneously firing LHA neurons, 70 (30%) were inhibited by D-PAG stimulation. Of these 70 neurons, 26/40 tested (65%) were glucose-sensitive, 16/19 (84%) were inhibited by morphine and 12/18 (67%) were inhibited by tail pinch. Glucose-sensitive neurons were selectively inhibited by morphine and tail pinch. Naloxone attenuated inhibitory responses to D-PAG stimulation, tail pinch and electrophoretic morphine. From intracellular recordings these polysynaptic inhibitory responses to D-PAG stimulation were considered to be inhibitory postsynaptic potentials (IPSPs) with 6.1 +/- 3.2 ms (mean +/- S.D.) latency and reversal membrane potential of about -78 mV. Since LHA glucose-sensitive neurons receive, selectively, both inhibitory opioid inputs from the D-PAG and inhibitory inputs through noxious stimulation, we suggest that D-PAG might be an intermediate site for transmission of noxious stimuli to the LHA.

Animals↗
PubMed1988

Tumor necrosis factor and interleukin-1 beta: suppression of food intake by direct action in the central nervous system.

Intracerebroventricular microinfusion of recombinant human tumor necrosis factor (rhTNF) and recombinant human interleukin-1 beta (rhIL-1 beta) suppressed food intake in rats. Central infusion of heat-inactivated rhTNF and rhIL-1 beta, bovine serum albumin, heparin or transforming growth factor-beta had no such effect. Central infusion of rhIL-1 beta did not affect the dipsogenic response to central administration of angiotensin II. Peripheral administration of rhTNF and rhIL-1 beta in doses equivalent to or higher than those administered centrally had no effect. Electrophoretically applied rhTNF and rhIL-1 beta specifically suppressed the activity of glucose-sensitive neurons in the lateral hypothalamic area. Glucose-insensitive neurons were little affected. The results suggest that TNF and IL-1 beta act directly in the central nervous system to suppress feeding, and this effect may be operative during acute and chronic disease.

Animals↗
PubMed1988

Internal and external information processing by lateral hypothalamic glucose-sensitive and insensitive neurons during bar press feeding in the monkey.

Single neuron activities in the lateral hypothalamic area (LHA) were recorded during bar press feeding task in the monkey. First registered neurons were sorted into 2 groups, glucose-sensitive (GS) and glucose-insensitive (GIS) neurons, depending on their glucose sensitivity. The firing variations to feeding, electrophoretically applied catecholamines and opiate, and to odor and taste stimuli were investigated. GS neurons responded to dopamine, noradrenaline and morphine more often than GIS neurons. In feeding task GS neurons responded during bar press (BP) and reward (RW) periods with long-lasting inhibition of firing and at cue tone (CT) with transient inhibition, while GIS neurons responded during BP and RW periods mainly with excitation and at cue light (CL) with excitation. A majority of GS neurons responded to both odor and taste stimuli more often than GIS neurons. Data suggest that these two kinds of neurons in the LHA may be involved in different functional aspects of feeding: GS neurons, mainly in internal information processing and reward mechanism, and GIS neurons, in external information processing and motor aspects.

Action Potentials↗
PubMed1988

Responses of rat lateral hypothalamic neuron activity to dorsal raphe nuclei stimulation.

1. The effects of dorsal raphe (DR) stimulation on neural activity in the rat lateral hypothalamic area (LHA), including specific glucose-sensitive neurons, were investigated by extracellular and intracellular recording in vivo, and the neurotransmitters involved were determined. 2. In 67 adult male anesthetized rats, 287 extracellular and 49 intracellular recordings of LHA responses to electrical stimulation of the DR were examined. 3. To determine neurotransmitter candidates, the effects of serotonin and the serotonin antagonists methysergide, lisuride, and (-)-propranolol were investigated by systemic administration and microelectrophoresis. 4. Of 287 spontaneously firing LHA neurons tested by DR stimulation, 157 (55%) were inhibited. Among these, 51% were glucose sensitive. The serotonin 1 receptor antagonists, lisuride and (-)-propranolol, attenuated the inhibitory responses to both DR stimulation and electrophoretic serotonin application. 5. Seventy-three (25%) were excited by DR stimulation, and 71% of these were glucose insensitive. Methysergide attenuated the excitatory responses to DR stimulation and the inhibitory response to electrophoretic serotonin application, but (-)-propranolol did not attenuate the excitation. 6. Intracellular recordings of LHA neurons during DR stimulation showed monosynaptic excitatory postsynaptic potentials (EPSPs) or inhibitory postsynaptic potentials (IPSPs) with 3.8 and 3.0 ms latency, respectively. The reversal potential for the former was approximately -17 and for the latter, -94 mV. 7. From the results we concluded that 75% of LHA glucose-sensitive neurons receive inhibitory serotonin inputs from the DR through serotonin 1 receptors, and 20% of glucose-insensitive neurons receive excitatory inputs from the DR through serotonin 2 receptors though 41% of these receive inhibitory inputs through serotonin 1 receptor.

Action Potentials↗
PubMed1988

[Reevaluation of clinical efficacy of piperacillin against complicated urinary tract infections].

Forty-six inpatients with complicated urinary tract infections (UTI) were treated with 2 g piperacillin (PIPC) twice a day through drip intravenous infusion. After 5 days, evaluation was made using the criteria proposed by the UTI Committee in Japan. The overall clinical efficacy was rated "excellent" in 4 (8.9%), "moderate" in 22 (47.8%), and "poor" in 20 (43.5%) cases with a total efficacy rate of 56.5% (26/46). We previously presented the clinical efficacy of PIPC in 74 cases with complicated UTI. Herein, a total of 120 cases were analyzed and these cases were divided into two groups. The overall clinical efficacy, bacteriological response, type of infection, background of patients and its safety were evaluated. Almost no change was seen for four years. Also this study revealed the usefulness against Enterococcus infections. In conclusion, PIPC is still a useful antimicrobial agent against complicated UTI even after the appearance of many new Cephems.

Adolescent↗
PubMed1987

Benign osteoblastoma of the temporal bone of an infant.

Benign osteoblastoma is a rare neoplasm of bone tissue most commonly involving the vertebral column and long bones. Occurrence in the calvarium is extremely rare, and no cases in infants have previously been described. We report a case of benign osteoblastoma occurring in the temporal squama of an infant. The clinical features of this type of tumor occurring in the calvarium are briefly discussed.

Age Factors↗
PubMed1987

Pseudomalignant myositis ossificans occurring in the hand.

This is a case report of a patient with pseudomalignant myositis ossificans of the hand. This entity is usually related to trauma, but there was no history of injury in this patient. Radiographic follow-up, histologic zone phenomena and computerized tomography are helpful in obtaining the correct diagnosis.

Adult↗
PubMed1987

Use of a series of ompF-ompC chimeric proteins for locating antigenic determinants recognized by monoclonal antibodies against the ompC and ompF proteins of the Escherichia coli outer membrane.

A method is presented for the efficient location of antigenic determinants using a series of chimeric proteins. By means of in vivo homologous recombination between the ompC and ompF genes coding for OmpC and OmpF, homologous proteins of the Escherichia coli outer membrane, a series of ompF-ompC chimeric genes was constructed (Nogami, T., Mizuno, T., & Mizushima, S. (1985) J. Bacteriol. 164, 797-801, and this work). The OmpF-OmpC chimeric proteins expressed by these genes were successfully used to locate antigenic determinants recognized by monoclonal antibodies, which specifically react with either the OmpC or OmpF protein. Interaction between monoclonal antibodies and the chimeric proteins was examined by means of either enzyme-linked immunosorbent assay or immunoblot analysis. The antigenic determinants recognized by three anti-OmpC antibodies and one anti-OmpF antibody were thus located. Finally, the polypeptides covering these regions were chemically synthesized for two of them and then tested as to their reactivity with the antibodies. The peptides reacted with the corresponding antibodies when the former were chemically coupled with bovine serum albumin. Most of the monoclonal antibodies isolated in this work were highly specific to the unfolded monomer of the protein against which the antibody was raised. But they did not react with the trimer, the native form. These results are discussed in relation to the structures and functions of the OmpC and OmpF proteins. The use of a series of monoclonal antibodies for studying the mechanism of protein translocation across the cytoplasmic membrane is also discussed.

Antibodies, Bacterial↗
PubMed1987

[The analysis of prognostic factors on postsurgical pyuria of benign prostatic hypertrophy].

The outcome of postsurgical pyuria in benign prostatic hypertrophy was studied in 87 patients, and the factors that might affect the outcome were determined. No significant differences were found between operation method and duration until normalization of pyuria, which was 75.5 +/- 46.0 days for transurethral resection of the prostate, 72.7 +/- 30.6 days for suprapubic prostatectomy and 69.3 +/- 32.7 days for retropubic prostatectomy. Prognostic factors were statistically analyzed preoperatively, at operation, and postoperatively. The definite prognostic factors were preoperative diabetes mellitus, preoperative pyuria, preoperative bacteriuria, and postoperative hypoproteinemia. The probable prognostic factors were old-age, preoperative indwelling catheters, heavy prostate tissue, postoperative bacteriuria, postoperative anemia and postoperative complications.

Aged↗
PubMed1986

Preliminary crystallographic study of a ribulose-1,5-bisphosphate carboxylase-oxygenase from Chromatium vinosum.

Crystals of a ribulose-1,5-bisphosphate carboxylase-oxygenase from Chromatium vinosum were obtained with the hanging-drop vapor diffusion technique, using polyethylene glycol 4000 as precipitant. The crystal belongs to the cubic system, space group I432, with unit cell dimension a = 245.9 A. An asymmetric unit includes one-quarter (L2S2, L: large subunit, S: small subunit) of a hexadecameric molecule (L8S8, 544,000 Mr), which is located on the crystallographic point symmetry 222 or 4. The crystal diffracts to at least 3.0 A resolution.

Chromatium↗
PubMed1986

Crystal structures of modified myoglobins. I. Heme orientation and structural changes around heme in myoglobins reconstituted with isopemptoheme, pemptoheme, 2-ethyldeuteroheme, and 4-ethyldeuteroheme.

The crystal structures of sperm whale metmyoglobins reconstituted with four modified hemes, isopemptoheme, pemptoheme, 2-ethyldeuteroheme, and 4-ethyldeuteroheme, have been determined and refined at 2.2 A resolution to R = 0.217, 0.218, 0.213, and 0.222, respectively. All the crystals of these myoglobins are isomorphous with that of native metmyoglobin. The structural changes of the modified myoglobin from the native myoglobin were examined on difference Fourier maps; the orientation of 4-ethyldeuteroheme in the heme pocket is such that the heme is rotated by 180 degrees about an axis through the alpha-gamma-meso carbons, whereas the orientations of the other three hemes are the same as that of the protoheme in the native myoglobin. The changes of the structures around the heme become greater in the order of isopemptoheme, 2-ethyldeuteroheme less than pemptoheme less than 4-ethyldeuteroheme. The magnitudes of the changes seem to be related to the oxygen affinities of these four reconstituted myoglobins.

Animals↗
PubMed1986

Crystal structures of modified myoglobins. II. Relation between oxygen affinity properties and structural changes around heme in myoglobins reconstituted with 2,4-diisopropyldeuteroheme, 2-isopropyl-4-vinyldeuteroheme, and 2-vinyl-4-isopropyldeuteroheme.

The crystal structures of sperm whale metmyoglobins reconstituted with three kinds of modified hemes, 2,4-diisopropyldeuteroheme, 2-isopropyl-4-vinyldeuteroheme, and 2-vinyl-4-isopropyldeuteroheme, have been determined and refined at 2.2 A resolution to R = 0.216, 0.219, and 0.195, respectively. All the crystals of these myoglobins are isomorphous with that of native metmyoglobin. The 2-vinyl-4-isopropyldeuteroheme was found to be in a reverse orientation, in which the heme plane is rotated by 180 degrees about an axis through the alpha-gamma-meso carbons, whereas the orientations of the other two hemes were the same as that of protoheme in native myoglobin. In the myoglobins with 2,4-diisopropyldeuteroheme and 2-vinyl-4-isopropyldeuteroheme, both of which have lower oxygen affinities than native myoglobin, the bulky isopropyl side chain pushes Phe 43 0.7 A toward His 64 (the distal histidine) in the former, and the whole E helix at most 1.5 A, including a 0.7 A shift of the His 64 imidazole ring, in the latter. The changes of the structures prevent His 64 from forming a hydrogen bond with the liganded oxygen molecule, so that these two modified myoglobins show low oxygen affinities. On the other hand, there is no such drastic displacement in myoglobin with 2-isopropyl-4-vinyldeuteroheme, which has a slightly higher oxygen affinity than native myoglobin.

Animals↗
PubMed1986

Barley leaf peroxidase: purification and characterization.

Peroxidase was prepared from extracts of barley leaves and separated into seven components, different in pI. The purification procedure comprised two parts. The first part was based on the fact that all the components had practically the same molecular weights. It consisted of fractionations with acetone and ammonium sulfate, ion-exchange chromatographies on CM-cellulose and DEAE-Sepharose CL-6B, and molecular-sieve chromatography on Ultrogel AcA44; the components were all purified together to near homogeneity on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and the procedure resulted in 1,200-fold purification with a yield of 39%. The ion-exchange chromatographies were carried out under conditions such that the components would not be adsorbed. In the second part, the enzyme preparation was separated into the seven components by repeating isoelectric electrophoresis. Their isoelectric points (pI) were 6.3, 6.8, 7.4, 8.3, 8.5, 8.7, and 9.3. The components other than the pI 6.3 and 6.8 components were each purified to homogeneity in the electrophoresis. The seven components thus prepared were the same in molecular weight on SDS-gel electrophoresis (44,000) and showed absorption maxima at the same wave-lengths (403, 496, and 534 nm), RZ (A403/A275) ranging from 2.09 to 2.81. Their protoheme IX contents were 0.81-1.07 mol/mol, and their true sugar contents 15-26% (g/g). The amino acid compositions suggest that the five components described above are not real isoenzymes, but exhibit different pI values due to differences in glycosyl residue. The pI 9.3 component was crystallized in spite of its high sugar content.

Crystallization↗