Biomedical subjects

S Horiuchi

Publications and source records attributed to S Horiuchi.

At least 289 records · Page 16Linked to original sources

PubMed1989

Monoclonal antibodies to chicken iodopsin.

The protein moiety of chicken iodopsin, R-photopsin, was purified from the chicken retina using a sucrose flotation method followed by two steps of column chromatography. Apparent molecular weights of R-photopsin and scotopsin (the protein moiety of chicken rhodopsin), which was partly purified in the process of purification of R-photopsin, were estimated to be 34,000 and 36,000, respectively, by sodium docecylsulfate-polyacrylamide gel electrophoresis. Using the purified R-photopsin as an antigen, four kinds of hybridoma cells which secreted monoclonal antibodies specific for R-photopsin and iodopsin were prepared. The antibodies thus obtained reacted with neither other chicken cone visual pigments nor rhodopsin as analyzed by immunoblots and immunoprecipitation methods. All the monoclonal antibodies stained the majority of the cone outer segments in chicken retina, while an antiserum raised against cattle rhodopsin stained the rod outer segments as well as some cone outer segments in the retina.

Animals↗

PubMed1989

Dynamics of ischaemic brain oedema fluid: 'dense tracer distribution around the focus', evaluated by peroxidase injection in the rat cortex.

Experimental cerebral ischaemia was produced by microembolization in rats. HRP (horseradish peroxidase) was then injected into the cerebral cortex and the extracellular fluid dynamics were observed. In the control group, there was a basic pattern in the migration of the tracer. In the ischaemic group, a 'dense tracer distribution around the focus' was found in addition to the basic pattern. This phenomenon could be observed from the second day after the ischaemic insults. The perivascular DAB reaction was marked, particularly around the focus. There was a vesicular uptake of the tracer in the vascular endothelium. This phenomenon appeared almost simultaneously with the active resolution of the oedema fluid. In addition, frequent mitotic figures were seen around the focus. It was thus possible to hypothesize that the 'dense tracer distribution around the focus' appeared at the site of active tissue reaction and had a close relationship with oedema resolution.

Animals↗

PubMed1989

In-vitro activity of DR-3355, an optically active isomer of ofloxacin, against bacterial pathogens associated with travellers' diarrhoea.

The in-vitro activity of DR-3355, the S-(-)-isomer of ofloxacin, was determined against bacterial pathogens associated with travellers' diarrhoea. DR-3355 was highly active against isolates of enteropathogenic Escherichia coli (MIC90 0.05 mg/l), Salmonella spp. (MIC90 0.10 mg/l), Shigella spp. (MIC90 0.10 mg/l), Campylobacter jejuni (MIC90 0.39 mg/l) and Vibrio parahaemolyticus (MIC90 0.39 mg/l). The activity of DR-3355 against these bacteria was generally two- to eight-fold greater than that of ofloxacin and equal to, or only two-fold less than, that of ciprofloxacin with the exception of isolates of C. jejuni, which were two-fold less susceptible to ciprofloxacin than to DR-3355.

Anti-Bacterial Agents↗

PubMed1989

[Serovars, antimicrobial resistance and conjugative R plasmids of Salmonella isolated from human during the period of 1966-1986 in Tokyo. Research Group for Infectious Enteric Diseases].

We examined 4,739 isolates of Salmonella isolated from patients with gastroenteritis during the period of 1966-1986 in Tokyo for the incidences of serovars, antibiotic resistance and conjugative R plasmids. The period of study was divided into three: 1966-73 (early period), 1974-79 (middle period), and 1980-86 (late period). The predominant serovars were S. typhimurium (34.3%), Infantis (5.6%), Panama (4.9%) in the middle period, S. typhimurium (31.7%), Paratyphi B (9.4%), Litchfield (7.3%) in the late period. These results were consistent with serovars of isolates from healthy citizens. The frequency of resistant isolates was as high as 86.9% in the early period, mostly streptomycin (SM)- and tetracycline (TC)-resistant isolates, but decreased significantly in the middle and the late periods, to 53.3 and 39.4%, respectively. The percentages of ampicillin (ABPC)-, chloramphenicol (CP)-, and kanamycin (KM)-resistant isolates increased in the late period. Strains carrying conjugative R plasmids were isolated as frequently as 57.8% of the total isolates in 1973, but as less frequently as 6.7% in 1981 indicating that the rate was roughly proportional to the incidence of the drug resistant isolates. The rate, however, increased gradually after 1981. The predominant resistance pattern of the R plasmids was TC-resistance in the early period, gradually changed into multiple and finally to AP-, CP-, KM-, SM-, TC- and sulfonamides-resistance in the late period.

Conjugation, Genetic↗

PubMed1989

Effects of pH and light exposure on the riboflavin-binding capacity in the rat lens.

To elucidate the binding mode of riboflavin to rat lens protein, we examined the effects of light exposure, different pH (4.0, 7.0 and 9.0) and dialysis on the lenticular riboflavin-binding capacity (LRBC). LRBC increased remarkably by light exposure, irrespective of pH. By dialysis, LRBC of a light-exposed incubation mixture decreased remarkably at pH 9.0, however, at pH 4.0 and 7.0, dialysis did not affect it significantly. Decrease in LRBC in light-exposed dialyzed samples at the higher pH may result from release of dialyzable bound riboflavin from binding protein. These data suggest that the dialyzed bound riboflavin at the higher pH may be responsible for a photosensitization of lens protein.

Animals↗

PubMed1989

Primary irritant reactions in the skin of the pika, Ochotona rufescens rufescens.

The skin of the pika (Ochotona rufescens rufescens) was found to be remarkably sensitive to the primary irritation of sodium hydroxide, as compared with the skin of the rabbit. After exposure to 0.1 N sodium hydroxide for 24 hr, the pika skin showed severe erosion, ulceration and necrosis as well as crust formation and hyperkeratosis with vascular dilation, and cell infiltration. The changes appeared already within 1 hr after 1 N or 3 hr after 0.1 N sodium hydroxide application. After application of acetic acid, changes were apparent while less remarkable.

Animals↗

PubMed1989

Endocytic pathway of high density lipoprotein via trans-Golgi system in rat resident peritoneal macrophages.

Interaction of high density lipoprotein (HDL) with rat resident peritoneal macrophages was investigated by morphological and biochemical approaches. Binding studies at 0 degree C demonstrated saturable binding sites for 125I-HDL on the surface membrane. When cells were incubated with 125I-HDL at 37 degrees C, the cell-associated radioactivity increased with time, but intracellular degradation of HDL did not occur. Rather, the cell-associated 125I-HDL was released intact into the medium. Two morphological probes were employed to visualize the post-binding fate of HDL. Horseradish peroxidase and ferritin conjugates of HDL showed specific bindings to the coated pits of the plasma membranes and were internalized and delivered through receptosomes to a trans-Golgi system. They were then resecreted as secretory vesicles from the cells. Parallel experiments with transferrin-horseradish peroxidase conjugates revealed an endocytic pathway identical or very similar to that observed with HDL. These results provide evidence that internalization and subsequent nonlysosomal pathway via the trans-Golgi system are involved in receptor-mediated endocytosis of HDL by macrophages.

Animals↗

PubMed1989

[A case of hereditary angioneurotic edema associated with systemic lupus erythematosus].

A 33-year-old woman noticed recurrent and sudden attacks of subcutaneous swelling of the extremities and face since the age of 4 years. Sometimes the attacks involved colicky abdominal pain. Her mother and younger sister had episodes of recurrent swelling of the extremities as well. Complement studies revealed low CH50, C1q, C4, and C1 inhibitor levels, with normal C3 and C5 levels. Similar reductions of CH50 C4 and C1 inhibitor levels were observed in her mother, older, and younger sisters. Therefore, she was diagnosed as hereditary angioneurotic edema. In addition, she was diagnosed as having a butterfly rash at the age of 20 years and had a history of solar sensitivity. Histologically the facial lesion showed liquefaction degeneration of the basal cell layer. Direct immunofluorescent staining of the affected skin lesion showed basement membrane-zone staining of IgG and IgM. Laboratory studies revealed lymphopenia and positive ANF. On the basis of the above findings, hereditary angioneurotic edema associated with systemic lupus erythematosus was diagnosed.

Adult↗

PubMed1989

[A case of superficial esophageal cancer with an intramural metastasis to the gastric wall].

Reported is a case of 61-year-old man with a superficial esophageal cancer that was associated with an intramural metastasis to the stomach. Examination of the upper G.I. tract revealed a slightly elevated lesion with an irregular surface at the left wall of the lower esophagus, and a large submucosal tumor with an ulcerous formation that had developed and had increased rapidly within a month. Thus a resection of the lower esophagus and a total gastrectomy were performed. Histopathologically, the tumor of the lower esophagus was determined as being a moderately differentiated squamous cell carcinoma with a deep invasion to the submucosal tissue. The submucosal tumor of the stomach also was found to be a moderately differentiated squamous carcinoma. Neither provided evidence, however, of a direct involvement of the gastric serosa may have metastasized from the neighboring lymph nodes or from other organs, nor of any continuous mucosal metastasis between the primary lesion of the esophagus and the submucosal tumor of the stomach. Judging from these findings, the case was diagnosed as an esophageal cancer with an intramural metastasis to the stomach.

Carcinoma, Squamous Cell↗

PubMed1989

[Experimental study on the changes of bile acids and their fractions after liver ischemia].

Serum bile acids and their fractions in the systemic and portal vein were measured after liver ischemia of 0, 30, 60, and 90 minutes with extracorporeal venous bypass in 20 dogs. The following results were obtained: 1) Total concentration of bile acids in the serum rapidly increased during the ischemic phase because of extinction of enterohepatic circulation due to flow of portal blood into the systemic circulation. 2) Portal blood flow decreased after recirculation of the liver, and this decrease was more severe in the 90-minute ischemic group than in the 30- and 60-minute groups. 3) After recirculation, increased bile acids were taken up by hepatocytes, and their concentrations in the systemic vein decreased markedly. The 90-minute ischemic group had a significantly slower rate of decrease compared to the 30- and 60-minute groups. This was due to its significantly lower portal blood flow rate. 4) Hepatocyte dysfunction was suggested in the 90-minute ischemic group, since the uptake of bile acids into the liver, especially dihydroxy- and deconjugated bile acids, significantly decreased. These results indicate that measurement of serum bile acids and their fractions is useful for estimating the liver function after liver ischemia.

Animals↗

PubMed1989

[Combination chemotherapy with ifosfamide, 5-fluorouracil, cisplatin for stage D2 prostatic cancer].

Twelve patients with stage D2 adenocarcinoma of the prostate were treated with the combination chemotherapy of ifosfamide (2 g/body, i.v., day 1-3), 5-fluorouracil (250 mg/body, i.v., day 1-5) and cisplatin (20-30 mg/body, i.v., day 1-5). The averaged age was 62 years (from 52 to 73 years) with mean performance status of 70% (from 40 to 90%). Six patients were refractory to prior hormone therapy or chemotherapy and the other six had received no prior treatment for prostatic cancer. Based on criteria of National Prostatic Cancer Project, 4 patients achieved partial response (PR) which was maintained from 11 to 23 months with the mean of 17.8 months. Two patients achieved objectively stable stage (NC). Response rate (PR + NC) was 50%. Response rate of patients without prior therapy was 80%, whereas that of hormone-resistant group was 30%. There was a trend toward unfavorable response in patients with prior therapy. Adverse effects were mild to moderate gastric problems and myelosuppression except in one case Adverse effects were mild to moderate gastric problems and myelosuppression except in one case with low performance status under 60%. IFP combination chemotherapy achieved favorable responses and toxicities were tolerable. Therefore, it appears worth while to study whether IFP combination chemotherapy could extend the life of patients with advanced prostatic cancer.

Adenocarcinoma↗

PubMed1989

[A case of spermatocytic seminoma].

In April, 1987, we treated a 33-year-old male patient who presented a painless swelling of the right scrotal content of 6 months duration. After surgery, the resected testis weighed 130 g, and the cut surface showed an edematous, white-yellow, homogenous tumor. A histopathological examination revealed a typical spermatocytic seminoma composed of three types of tumor cells. The small cells had pyknotic nuclei and an eosinophilic cytoplasm while the medium-sized cells and most of the giant cells had nuclei containing granular chromatins. Some of giant cells contained a filamentous, chromatin-like spireme of primary spermatocytes. A chest X-ray, CT scanning and lymphography revealed no metastatic lesions, and the patient is still alive with no evidence of disease 10 months after the orchiectomy.

Adult↗

PubMed1988

Evidence against in vivo presence of 2-(2-furoyl)-4(5)-(2-furanyl)-1H-imidazole, a major fluorescent advanced end product generated by nonenzymatic glycosylation.

The reaction of protein amino groups with glucose leads to the formation of a stable Amadori product via a Schiff base adduct, which is further converted to advanced glycosylation end products (AGE) with color and unique fluorescence characteristics. 2-(2-Furoyl)-4(5)-(2-furanyl)-1H-imidazole (FFI) was recently identified as a major fluorescent compound (Ponger, S., Ulrich, P.C., Bencsath, F.A., and Cerami, A. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 2684-2688). Its in vivo and in situ presence was further demonstrated by radioimmunoassays (Chang, J.C.F., Ulrich, P.C., Bucala, R., and Cerami, A. (1985) J. Biol. Chem. 260, 7970-7974). In the present study the occurrence of FFI in AGE-proteins was reassessed. The radioimmunoassay using anti-FFI antibody and high performance liquid chromatography failed to detect FFI in AGE samples obtained from bovine serum albumin, poly-L-lysine, oligo-L-lysine, and L-lysine. Even after acid hydrolysis or proteinase K digestion, FFI was undetectable. To our surprise, however, the addition of ammonia to these acid hydrolysate led to the production of FFI, suggesting the importance of acid hydrolysis and subsequent reaction with ammonia for the generation of FFI. This observation was fully supported by model experiments using AGE-samples prepared by incubating glucose with monoaminocarboxylic acids such as beta-alanine, gamma-aminobutyric acid, and epsilon-aminocaproic acid. Thus, a nonfluorescent FFI precursor is produced by acid hydrolysis, and its conversion to fluorescent FFI occurs upon subsequent reaction with ammonia, the evidence against the presence of FFI in AGE-proteins.

Ammonia↗

PubMed1988

Endocytic uptake of nonenzymatically glycosylated proteins is mediated by a scavenger receptor for aldehyde-modified proteins.

Long term incubation of proteins with glucose, named the Maillard reaction (Maillard, L. C. (1912) C. R. Acad. Sci. (Paris) 154, 66-68), gives rise to advanced glycosylation end product (AGE) with fluorescence, color, as well as cross-linked properties. The receptor-mediated endocytosis of AGE-proteins by macrophages was reported (Vlassara, H., Brownlee, M., and Cerami, A. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 5588-5592). The present study on the binding of AGE-bovine serum albumin (BSA) to rat peritoneal macrophages and sinusoidal liver cells demonstrated the presence of a saturable, high affinity receptor for AGE-BSA with Kd = 2.4 x 10(-7) M (macrophages) and 2.1 x 10(-7) M (sinusoidal cells). The cellular binding of AGE-BSA and its endocytic uptake by these cells were competitively inhibited by BSA preparations modified with aliphatic aldehydes such as formaldehyde or glycolaldehyde, ligands known to be specific for a scavenger receptor for aldehyde-modified proteins (Horiuchi, S., Murakami, M., Takata, K., and Morino, Y. (1986). J. Biol. Chem. 261, 4962-4966). These ligands also had a profound in vivo effect on the plasma clearance of 125I-AGE-BSA as well as its hepatic uptake. Thus, endocytic uptake of AGE-proteins by macrophages appeared to be mediated by a scavenger receptor for aldehyde-modified proteins. This provides evidence for the biological importance of the scavenger receptor in eliminating senescent macromolecules from the circulation.

Animals↗

PubMed1988

Purification and characterization of cathepsin D-like proteinase from the tadpole tail of bullfrog, Rana catesbeiana.

1. An acid aspartic proteinase in the regressing tadpole tail was purified about 800-fold with a 36% recovery. 2. The mol. wt of the enzyme was found to be 42,000 on gel filtration and 38,000 on sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively. 3. The purified enzyme had a maximum activity at pH 3.5 and an apparent Km of 0.084% with acid-denatured hemoglobin as substrate. 4. The enzyme activity was strongly inhibited by pepstatin. In addition, diazoacetylnorleucine methyl ester inactivated the enzyme in the presence of cupric ions. 5. The enzyme was identified as a cathepsin D (EC. 3.4.23.5)-like proteinase.

Animals↗

PubMed1988

Adaptation of a deep-sea cephalopod to the photic environment. Evidence for three visual pigments.

Watasenia scintillans, a bioluminescent deep-sea squid, has a specially developed eye with a large open pupil and three visual pigments. Photoreceptor cells (outer segment: 476 micron; inner segment: 99 micron) were long in the small area of the ventral retina receiving downwelling light, whereas they were short (outer segment: 207 micron; inner segment: 44 micron) in the other regions of the retina. The short photoreceptor cells contained the visual pigment with retinal (lambda max approximately 484 nm), probably for the purpose of adapting to their environmental light. The outer segment of the long photoreceptor cells consisted of two strata, a pinkish proximal area and a yellow distal area. The visual pigment with 3-dehydroretinal (lambda max approximately 500 nm) was located in the pinkish proximal area, giving high sensitivity at longer wavelengths. A newly found pigment (lambda max approximately 471 nm) was in the yellow distal area. The small area of the ventral retina containing two visual pigments is thought to have a high and broad spectral sensitivity, which is useful for distinguishing the bioluminescence of squids of the same species in their environmental downwelling light. These findings were obtained by partial bleaching of the extracted pigment from various areas of the retina and by high-performance liquid chromatographic analysis of the chromophore, complemented by microscopic observations.

Adaptation, Physiological↗

PubMed1988

Receptor-mediated internalization of high density lipoprotein by rat sinusoidal liver cells: identification of a nonlysosomal endocytic pathway by fluorescence-labeled ligand.

Rat sinusoidal liver cells possess the surface receptor for high density lipoprotein (HDL) (Murakami, M., S. Horiuchi, K. Takata, and Y. Morino. 1987. J. Biochem. (Tokyo) 101: 729-741). The present study was undertaken to determine whether cell surface-bound HDL underwent subsequent endocytic internalization by using 125I-labeled HDL and fluorescein isothiocyanate-labeled HDL (FITC-HDL). The cell-associated radioactivity obtained by a 40-min incubation with 125I-labeled HDL at 37 degrees C was released into the medium as acid-precipitable forms upon further incubation at 37 degrees C. When further incubated at 0 degree C instead of 37 degrees C, however, this release was significantly reduced. A similar phenomenon was observed after the cell-associated ligands had been treated with trypsin. The cell-associated ligands obtained after a 1-hr incubation with 125I-labeled HDL at 0 degree C were largely counted for by those bound to the outer surface of the cells, thus suggesting that HDL is internalized into cells at 37 degrees C but not at 0 degree C. Moreover, when cells were incubated with FITC-HDL at 0 degree C, the cell-associated ligands were found in a pH 7.2 +/- 0.1 compartment, whereas when incubated at 37 degrees C, its microenvironmental pH became much more acidic, exhibiting pH 6.2 +/- 0.1. Furthermore, this value returned to 7.1 +/- 0.1 upon treatment with carbonylcyanide m-chlorophenylhydrazone known to dissipate the total protonomotive force. These results suggest, therefore, that the internalization process does follow receptor-mediated binding of HDL in rat sinusoidal liver cells. This notion was also supported by fluorescence microscopic observations.

Animals↗

PubMed1988

[Treatment of complicated urinary tract infections by ofloxacin].

To study the treatment effects of ofloxacin (OFLX) on the patients with complicated urinary tract infections (UTI), OFLX at a daily dose of 600 mg divided into either two or three doses per day, was administered for 14 days to 114 patients with complicated UTI. Among the 114 patients, 67 patients satisfied the criteria for clinical evaluation of complicated UTI. One hundred and one organisms were isolated from these patients' urine. Among them, 82 organisms were eliminated following OFLX administration. Twenty organisms appeared newly by the replacement of organisms. Among them, 6 organisms belonged to Candida sp. As to the overall efficacy of OFLX, an excellent response was seen in 37.3% and sum of efficacy rate was 65.7%. Side effects were observed in 3 of the 114 patients. These results indicate that OFLX is both safe and effective enough to be used for the treatment of the patients associated with complicated UTI.

Adult↗