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Biomedical subjects

A Sano

Publications and source records attributed to A Sano.

At least 109 records · Page 6Linked to original sources
PubMed1997

Possible involvement of nitric oxide synthase in oxidative stress-induced endothelial cell injury.

The purpose of this study was to characterize the protective effect of NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase, on oxidative stress-induced endothelial cell injury. Intracellular oxidative stress was induced by 1-chloro-2,4-dinitrobenzene, a glutathione (GSH) depleting agent, and the leakage of intracellular lactate dehydrogenase was measured as a marker of cell injury. Addition of 1-chloro-2,4-dinitrobenzene (100-500 microM) induced leakage of lactate dehydrogenase from endothelial cells, and the leakage of lactate dehydrogenase was strongly attenuated by L-NAME, but not by NG-methyl-L-arginine, also an inhibitor of nitric oxide synthase. However, cell injury induced by the Ca2+ ionophore ionomycin was not affected by L-NAME or NG-methyl-L-arginine. Moreover, neither L-NAME nor NG-methyl-L-arginine affected GSH depleting agent-induced or H2O2-induced cell injury in a rat foetal lung fibroblast cell line which lacks nitric oxide synthase. These results suggest that the protective effect of L-NAME is likely to be related to nitric oxide synthase, while the inhibition of nitric oxide production may not be involved in the protective effect of L-NAME, since NG-methyl-L-arginine did not affect endothelial cell injury.

Animals↗
PubMed1997

Improved separation and determination of phospholipids in animal tissues employing solid phase extraction.

Separation of five glycerophospholipids having different polar groups, phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylglycerol (PG) and cardiolipin (CL), was investigated by means of solid-phase extraction (SPE) cartridges. First, the phospholipids were retained in an aminopropyl-bonded phase (NH2) cartridge and subsequently eluted as neutral (PC and PE) and acidic (PS, PG and CL) glycerophospholipid fractions. Secondly, a combination of silica gel (SI) cartridge and NH2 cartridge was employed to separate five glycerophospholipids. The polarity of the eluent was responsible for neutral glycerophospholipid separation. Concerning acidic glycerophospholipids, the separation of PG and CL from PS depended mainly on the pH of the eluents, and the separation of PG and CL was affected by the solvent, depending on eluent polarities. Favorable recovery (not less than 95%, for five authentic phospholipids, 10-100 micrograms each) and repeatability (sigma = 2.3 for 10 micrograms ranges) were attained by the present method. This method of separation was applicable to the analysis of phospholipids in biological samples.

Animals↗
PubMed1997

Prosaposin, a neurotrophic factor: presence and properties in milk.

The presence of prosaposin, the precursor of the sphingolipid activator proteins (saposins A, B, C, and D), was investigated in bovine milk. The milk proteins were resolved by SDS-PAGE, blotted onto nitrocellulose sheets, and immunostained. Each of three appropriate antibodies defined a band from milk that matched in mobility the reference prosaposin from human milk at a relative molecular mass of 66,000. Evidence of mature saposins was not found. Prosaposin was detected in milk of other species chimpanzee, rhesus, goat, and rat) and was consistently observed in samples of retail milk and from individual cows. Prosaposin was not associated with particulate matter (fat globules, casein micelles, membrane fragments, and somatic cells) in either human or bovine milk. Rather, prosaposin was located exclusively in the milk serum (whey), existing in monomeric form, as revealed by nondenaturing PAGE. A commercial whey protein concentrate (75% protein) appeared to retain milk prosaposin quantitatively. Properties that were useful in the isolation of prosaposin from milk were its binding to concanavalin A, retention by anion-exchange cellulose, and resistance to precipitation by heating. The possibility that bovine milk prosaposin nutritionally benefits the humans who consume it is enhanced by the fact that only part of its saposin C segment is required for neurotrophic activity.

Animals↗
PubMed1997

[Potential of photodynamic therapy with a second-generation sensitizer: mono-L-aspartyl chlorin e6].

We evaluated the potential for photodynamic therapy of a new photosensitizer, mono-L-aspartyl chlorin e6 (NPe6), whose tissue uptake and clearance are rapid. Firstly, NPe6 solution was exposed to a diode laser at 664 nm that fits the maximum absorption of NPe6. Immediately after laser exposure, the solution was subjected to electron spin resonance (ESR) to detect generation of activated oxygen species. With ESR, O2-, .OH, and 1O2 were detected in the NPe6 solution. O2- and .OH disappeared when superoxide dismutase was added to the solution. Next, the fundi of pigmented rabbits were irradiated with the diode laser after administration of NPe6. Histopathologically, there was necrosis of endothelial cells and vascular occlusion in the choroid, especially in the choriocapillaris. Retinal pigment epithelial cells were also injured. In contrast, the sensory retina was undamaged even after use of a large amount of dye. This new combination of NPe6 and diode laser at 664 nm enables us to occlude choroidal vessels efficiently by generating various activated oxygen species. Thus, photodynamic therapy with NPe6 is potentially useful in treating retinochoroidal involvement.

Animals↗
PubMed1997

[Experience in treatment of patients with locally advanced or recurrent breast cancer: intraarterial infusion chemotherapy combined with radiotherapy].

For the purpose of local control and breast conservation, intraarterial infusion chemotherapy combined with radiotherapy has been indicated in patients with locally advanced breast cancer both in primary and recurrent cases. The present series, evaluated during the past 4 years, consisted of 15 patients 35-83 years of age, with invasive ductal carcinoma, including 10 with primary breast cancer (stage IIIb: 1; IV: 9) and 5 with postoperative recurrence (stage IIIb: 2, IV: 3). Intraarterial chemotherapy is started, basically infusing ADM 50 mg, MMC 10 mg and CDDP 50 mg into the internal thoracic and/or subclavian artery 1-3 times, followed by reduction surgery (quadrantectomy: 4, wide resection: 2) and radiotherapy to the breast, supraclavicular, parasternal and cervical regions according to tumor extent. Local response after arterial infusion was CR: 2, PR: 10, NC: 3 (response rate: 73%). The response rate of distant metastases after arterial infusion was 73%. Of 10 patients with primary breast cancer, recurrence was noted in 1. Breast conservation was successful in 8 of 10 patients. One of them, in stage IIIb, has survived for 4.5 years with no evidence of disease and with breast conservation. Five patients with postoperative recurrence showed CR with no recurrence after intraarterial chemotherapy and radiotherapy. Acute skin reaction occurred in 6 patients, and was especially frequent in patients with postoperative recurrence (4 of 5). According to these results, combined therapy affords breast conservation even in patients with locally advanced breast cancer, and improves patient's QOL in stage IV.

Adult↗
PubMed1997

Evaluation of tapered-end toothbrushes regarding subgingival access efficacy.

The purpose of this in vitro study was to determine how two toothbrushes with highly tapered-end bristle designs compared to a conventional, slightly tapered toothbrush. Toothbrushing was carried out in the laboratory in order to evaluate the simulated subgingival efficacy of the three toothbrush designs. The performance of the three brushes was assessed by measuring the "subgingival regions" of gold-coated typodont left maxillary central teeth where the gold coating had been removed during brushing. The two toothbrushes with highly tapered bristles were statistically significantly (p < 0.01) more effective in removing the gold coating than the conventional toothbrush with slightly tapered bristles on the subgingival area on the anterior typodont teeth.

Analysis of Variance↗
PubMed1996

Prosaposin facilitates sciatic nerve regeneration in vivo.

Prosaposin, a multifunctional protein, is the precursor of saposins, which activate sphingolipid hydrolases. In addition to acting as a precursor for saposins, prosaposin has been shown to rescue hippocampal CA1 neurons from lethal ischemic damage in vivo and to promote neurite extension of neuroblastoma cells in vitro. Here we show that prosaposin, when added to a collagen-filled nerve guide after sciatic nerve transection in guinea pigs, increased dramatically the number of regenerating nerve fibers within the guide. To identify the target neurons of prosaposin during peripheral nerve regeneration, we determined the degree of atrophy and chromatolysis of neurons in the spinal anterior horn and dorsal root ganglia on the prosaposin-treated and untreated side. The effect of prosaposin on large spinal neurons and small neurons of the dorsal root ganglion was more conspicuous. Subsequent immunohistochemistry demonstrated that the atrophy of cholinergic large neurons in the anterior horn is prevented to significant extent by prosaposin treatment. These findings suggest that prosaposin promotes peripheral nerve regeneration by acting on alpha-motor neurons in the anterior horn and on small sensory neurons in the dorsal root ganglion. The present study raises the possibility of using prosaposin as a tool for the treatment of peripheral nerve injuries.

Animals↗
PubMed1996

A hydrophilic peptide comprising 18 amino acid residues of the prosaposin sequence has neurotrophic activity in vitro and in vivo.

Prosaposin, a 517-amino-acid glycoprotein, not only acts as the precursor of saposin A, B, C, and D but also possesses neurotrophic activity to rescue hippocampal CA1 neurons from ischemic damage in vivo and to promote neurite extension of neuroblastoma cells in vitro. Recently, the trophic activity of prosaposin on human neuroblastoma cells has been shown to reside in the NH2-terminal hydrophilic sequence (LIDNNRTEEILY) of the human saposin C. Here we show that prosaposin, saposin C, and a peptide comprising the 18-amino-acid sequence (18-mer peptide; LSELIINNATEELLIKGL) located in the NH2-terminal hydrophilic sequence of the rat saposin C-domain promoted survival and neurite outgrowth of cultured rat hippocampal neurons in a dose-dependent manner. Moreover, infusion for 7 days of the 18-mer peptide into the lateral ventricle of gerbils, starting either 2 h before or immediately after 3 min of forebrain ischemia, protected ischemia-induced learning disability and hippocampal CA1 neuronal loss. Thus, we ascribe the in vitro and in vivo trophic actions of prosaposin on hippocampal neurons to the linear 18-mer sequence and raise the possibility that this peptide can be used as an agent for the treatment of forebrain ischemic damage.

Amino Acid Sequence↗
PubMed1996

A unique origin and multistep process for the generation of expanded DRPLA triplet repeats.

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder associated with the expansion of a CAG repeat at chromosome band 12p13. Epidemiological studies have demonstrated an increased prevalence of DRPLA in Japan, although several DRPLA kindreds of non-Japanese ancestry have been identified. To define the molecular basis for this geographic variation in prevalence, we have analyzed haplotypes around the repeat in several different ethnic groups. Two intragenic biallelic polymorphisms distinguished three haplotypes, each of which formed a predominant haplotype found in the three major racial populations. All the expanded repeats of Japanese and Caucasian patients studied were associated with a particular haplotype, which otherwise was associated with longer repeats commonly found in Asians. Our results support a multi-step model for repeat expansion, and suggest that expanded DRPLA repeats may have evolved from an ancient chromosomal haplotype of Asian origin. We also propose that a combination of a highly polymorphic microsatellite marker with relatively stable biallelic markers in a range of PCR amplification is a powerful tool for studies on human genome diversity, which may reveal the ancient human migration and the formation of ethnic groups.

Black or African American↗
PubMed1996

Histopathology of paracoccidioidomycotic infection in athymic and euthymic mice: a sequential study.

We report the comparative and sequential histologic analysis of lesions developed by Paracoccidioides brasiliensis-infected athymic and euthymic BALB/c mice, using conventional and specific stain to characterize the morphology of fungi and inflammatory cells as well as the extracellular matrix patterns. In both groups, neutrophils and macrophages were the predominant cells; macrophage transition to giant and epithelioid cells was observed. Degenerated fungi and fungal dust were associated with local neutropil infiltration and the presence of pseudoxantomatous macrophages. Paracoccidioides brasiliensis are always found within an extracellular matrix microenvironment. The main differences between lesions developed by nu/+ and nude (nu/nu) mice resided in the more pronounced encapsulating tendency in the former ones. In both groups of animals, lesions in several organs were associated with extensive hemopoiesis. At the first week of infection, there was evidence of fungal destruction and control of its proliferation in both mouse groups. At the fourth and seventh weeks, nu/+ mice maintained the control of the infection, as shown by the scarce numbers of budding yeast cells, while experimental nu/nu mice showed a tumor-like progression of the disease with a striking increase in fungal load in many organs (e.g., omental and mesenteric milky spots, lymph nodes, spleen), some of which present their structure replaced by granulomatous lesions.

Animals↗
PubMed1996

Paracoccidioides brasiliensis infection in nude mice: studies with isolates differing in virulence and definition of their T cell-dependent and T cell-independent components.

Athymic and euthymic BALB/c mice infected with highly (Pb18) or slightly (Pb265) virulent Paracoccidioides brasiliensis isolates were compared regarding mortality, presence of viable yeasts, specific immunoglobulin M (IgM) and IgG titers, and the antigen recognition patterns of these antibodies. Isolate Pb18 caused a more severe disease in athymic mice, as supported by higher number of infected organs and shorter survival times. These animals, however, were resistant to Pb265 infection. High titers of antibodies were found only in euthymic mice, seven weeks after Pb18 infection. At this time, euthymic animals presented IgG antibodies to numerous protein bands that were not detected at four weeks postinfection or after Pb265 inoculation. In contrast, antibodies from athymic mice always reacted with few antigen bands. Although the majority of P. brasiliensis antigens are T cell-dependent, the immunodominant gp43 and also the 41.5- and 27.5-kD antigens are here, for the first time, characterized as T cell-independent antigens of P. brasiliensis.

Animals↗
PubMed1995

New method for evaluating left ventricular wall motion by color-coded tissue Doppler imaging: in vitro and in vivo studies.

OBJECTIVES: The aim of this study was to examine the accuracy and validity of a newly developed tissue Doppler imaging system in in vitro and in vivo studies. BACKGROUND: Because quantitative measurement of wall motion velocity in real time is still difficult by conventional echocardiography, we developed a new system for evaluating ventricular wall motion by analyzing Doppler signals from cardiac tissue. METHODS: We used a modified Doppler color imaging system, omitting the high pass filter to allow Doppler signals from cardiac tissue to enter the auto-correlator. Ultrasound carrier and pulse repetition frequencies were 3.75 MHz and 3.0 to 6.0 kHz, respectively. Under these conditions, the lowest measurable velocity was 0.2 cm/s. RESULTS: In the rotating sponge model, the measured velocity correlated well with the actual velocity (y = 0.97x + 2.17, r = 0.99). In clinical settings, the mid-ejection mean velocity at either endocardial or epicardial sites of the left ventricular posterior wall measured by M-mode tissue Doppler imaging correlated well with that measured by conventional M-mode echocardiography (y = 0.94x + 0.64, r = 0.99). During systole, in healthy subjects, the anterior left ventricular wall was color-coded blue and the posterior wall was color-coded red, whereas the akinetic regions associated with myocardial infarction showed no color throughout the cardiac cycle. The ventricular posterior wall excursion velocity, defined as the difference between velocities at the endocardial and epicardial sites, was significantly slower in patients with dilated cardiomyopathy (0.4 +/- 0.3 cm/s) than in normal subjects (2.0 +/- 0.6 cm/s). CONCLUSIONS: These results indicate that the present system accurately represents tissue velocity and can create two-dimensional color images that facilitate visual assessment of ventricular wall motion.

Adult↗
PubMed1995

Carmofur-induced leukoencephalopathy: MRI.

Carmofur, a derivative of 5-fluorouracil, has recently been noted to have an infrequent but serious association with leukoencephalopathy. To our knowledge, there has been no report of early MRI findings in this leukoencephalopathy. We describe a case in which diffuse high signal intensity of the entire cerebral white matter, including the corpus callosum, was seen on T2-weighted magnetic resonance images. Although similar findings can be seen in many other diseases, carmofur-induced leukoencephalopathy should be suspected in a patient treated with carmofur. It is important to know the clinical and MRI characteristics of this condition, for early diagnosis and better prognosis.

Antineoplastic Agents↗
PubMed1995

Expression of Lewis-related antigen and prognosis in stage I non-small cell lung cancer.

Immunohistochemical expression of Lewisy, sialyl Lewisx, and sialyl Lewisa were examined in relation to blood vessel invasion and prognosis in 133 patients with stage I non-small cell lung cancer who had a curative resection from 1980 to 1991. Expression of sialyl Lewisx in adenocarcinomas was higher than in squamous cell and large cell carcinomas, and Lewisy immunoreactivity was the highest among the three antigens. The frequency of blood vessel invasion was significantly higher in tumors with expression of Lewisy or sialyl Lewis antigen (sialyl Lewisx or sialyl Lewisa), however, Lewisy expression was even more significant. The postoperative survival was significantly shorter when tumors expressed both the Lewisy and sialyl Lewis antigen. However, the survival of patients with either Lewisy or sialyl Lewis antigen expression was similar to that of patients whose tumors did not express either the Lewisy or sialyl Lewis antigens. These results suggest that Lewisy and sialyl Lewis antigen may be of prognostic value for metastatic potential but have different functional roles in tumor cells.

Adenocarcinoma↗
PubMed1995

Myocardial velocity gradient as a new indicator of regional left ventricular contraction: detection by a two-dimensional tissue Doppler imaging technique.

OBJECTIVES: This study was performed to assess a new indicator of regional left ventricular contraction determined by a two-dimensional tissue Doppler imaging technique. BACKGROUND: Recent studies have demonstrated that instantaneous tissue motion velocity can be noninvasively assessed by tissue Doppler imaging. However, quantitative assessment of regional left ventricular contraction is still difficult because of the effects of the Doppler angle of incidence and parallel motion of the whole heart. METHODS: We assessed left ventricular wall motion in 11 normal subjects, 14 patients with an old myocardial infarction (anteroseptal in 7, posterior in 7) and 8 patients with dilated cardiomyopathy. Tissue Doppler velocity was corrected by the Doppler angle of incidence after the hypothetical center of contraction was set. Subsequently, the myocardial velocity gradient between the endocardium and epicardium was determined from the velocity profile along each radial line from the center of contraction by using least squares linear regression. RESULTS: In normal subjects, peak myocardial velocity gradient was lower in the anteroseptal wall (mean [+/- SD] 1.69 +/- 0.53 s-1) than in the posterior wall (3.28 +/- 0.67 s-1, p < 0.01). Myocardial velocity gradient in the infarct regions was significantly lower (anteroseptal 0.58 +/- 0.41 s-1, p < 0.05; posterior 0.17 +/- 0.27 s-1, p < 0.01) than that in normal subjects as well as that in the corresponding noninfarct regions (2.84 +/- 0.37 s-1 and 1.48 +/- 0.25 s-1, p < 0.01, respectively). In patients with dilated cardiomyopathy, myocardial velocity gradient was generally lower (anteroseptal 0.72 +/- 0.59 s-1; posterior 0.93 +/- 0.67 s-1) than that in normal subjects (p < 0.01). CONCLUSIONS: These results demonstrate that regional left ventricular contraction can be quantitatively assessed by the myocardial velocity gradient derived from two-dimensional tissue Doppler imaging. We suggest that myocardial velocity gradient has potential for the quantitative assessment of regional left ventricular contraction abnormalities in patients.

Adult↗