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Biomedical subjects

T Ando

Publications and source records attributed to T Ando.

At least 343 records · Page 19Linked to original sources
PubMed1994

Asbestos and nonasbestos fiber content in lung tissue of Japanese patients with malignant mesothelioma.

BACKGROUND: Pulmonary fiber content of both asbestos and nonasbestos types were evaluated in Japanese patients with malignant pleural mesotheliomas. METHODS: Pulmonary fiber content was analyzed in 16 patients and 16 case-matched control subjects by transmission electron microscopy with energy-dispersive X-ray analysis using a low-temperature ashing procedure. RESULTS: The geometric mean content of total asbestos was significantly higher in the patients (22.0 x 10(6) fibers/g dry lung) than in the control subjects (2.24 x 10(6) fibers/g dry lung) (P < 0.01). When the asbestos content was analyzed by fiber type, the geometric means were also consistently and significantly higher among the patients compared with the control subjects (P < 0.01). Results were as follows: (1) amosite: patients 3.94 times 10(6) versus control subjects 0.23 x 10(6); (2) crocidolite: patients 3.56 times 10(6) versus control subjects 0.35 times 10(6); (3) total amphiboles: patients 16.0 times 10(6) versus control subjects 0.77 times 10(6); and (4) chrysotile: patients 3.76 times 10(6) versus control subjects 1.01 times 10(6). However, when individual total asbestos content was considered, 7 of the 16 patients (44%) had levels lower than the highest value noted among the control subjects. Pulmonary fiber content of patients and control subjects also revealed the presence of nonasbestos fibers. The geometric mean of nonasbestos fibers was significantly higher in the patients (87.3 x 10(6)) than in control subjects (33.8 x 10(6)) (P < 0.01). The major type of nonasbestos fibers in both groups was aluminum silicates. The mean of ratios of nonasbestos fiber contents to total asbestos contents in the patients and control subjects was 7.0 and 17.3, respectively. CONCLUSIONS: The results were mainly in agreement with the findings of earlier investigations, but fiber content of both chrysotile and nonasbestos fiber as well as those of amphibole asbestos were significantly higher in the patients than in the control subjects.

Adult↗
PubMed1994

Complete 5' noncoding region is necessary for the efficient internal initiation of hepatitis C virus RNA.

The mechanism of translational initiation by the 5' noncoding region (5'NCR) of hepatitis C virus (HCV) genome was analyzed. Using an in vitro translation system with artificial RNA containing a modified 5' NCR of HCV under the various KCl conditions, nucleotides (nt.) 62 to 341 of the HCV 5'NCR were not functional as an internal ribosome entry site (IRES). However, the full-length 5'NCR (nt. 1 to 341) produced an efficient internal initiation. To identify the essential region of the HCV-IRES, various mutants were produced in which stem-loops, predicted by secondary structure analysis of the HCV 5'NCR, were deleted. These constructs were analyzed by in vitro translation. Comparison of translation efficiency among these mutants suggested that the alpha- or both alpha- and beta-branches of domain II are essential for efficient translation. Moreover, the formation of correct secondary structure of IRES seems to be stabilized by the presence of domain I in 5'NCR. Furthermore, the uncapped 5'NCR of HCV promotes translation more efficiently than capped truncated 5'NCR constructs. Our results strongly suggested that complete 5'NCR containing all stem-loop structures is necessary for initiation by HCV-IRES.

Base Sequence↗
PubMed1994

Structure and activity of Bombyx PBAN.

Two structurally related molecular species of pheromone biosynthesis activating neuropeptides (PBANs), PBAN-I and -II, were isolated from adult heads of the silkworm, Bombyx mori, and characterized. PBAN-I is a carboxyl-terminally amidated 33-residue peptide. Structure-activity relationship studies revealed that 1) its carboxyl-terminal pentapeptide is the smallest size showing activity, 2) the carboxyl-terminal amide is indispensable for activity, and 3) oxidation of three Met residues in PBAN-I to Met(O) (methionine sulfoxide) caused marked enhancement of activity, and the three Met(O) residues contribute equally to the enhancement of activity. Molecular design of PBAN analogs using a carboxyl-terminal hexapeptide showed that modification of the amino-terminal amino group brought about a dramatic increase in activity. This increase was presumed to be mainly due to the increased stability in hemolymph. PBANs share the common carboxyl-terminal sequence, -Phe-Xaa-Pro-Arg-Leu-NH2, with myotropic peptides isolated from locust and cockroach. Examination of cross-activity of these two groups of peptides revealed that PBAN and its analogs exhibited myotropic activity comparable to myotropic peptides, while myotropic peptides showed extremely high pheromonotropic activity. In B. mori, PBAN activates sex pheromone (bombykol) production presumably by promoting the reduction reaction from acyl to alcohol, which is the last step in the biosynthesis of bombykol.

Amino Acid Sequence↗
PubMed1994

A new triphenylethylene derivative, TAT-59; hormone receptors; insulin-like growth factor 1; and growth suppression of hormone-dependent MCF-7 tumors in athymic mice.

TAT-59 ((E)-4-[1-[4-[2-(dimethylamino)ethoxy]-phenyl]-2-(4- isopropyl)phenyl-1-butenyl]-phenyl-monophosphate) treatment was performed on hormone-dependent MCF-7 tumors in athymic mice. TAT-59 given at 1, 5, and 20 mg/kg inhibited the estrogen-stimulated growth of MCF-7 tumors in athymic mice in a dose-dependent fashion. The most clear decrease in tumor growth was shown in the TAT-59 alone group, although it was not dramatic. Average serum concentrations of DP-TAT-59((Z)-[1-[4-[2-(dimethylamino)- ethoxy]phenyl]-2-(4-isopropyl)phenyl-1-butenyl]-4-hydroxybenzene) and DM-DP-TAT-59(desmethyl-DP-TAT-59), metabolites of TAT-59, increased in a dose-dependent manner. Much higher levels of DP-TAT-59 and DM-DP-TAT-59 were shown in tumors (target tissues of estrogen) as compared with muscles (nontarget tissues of estrogen) or serum. A serum concentration of DP-TAT-59 or DM-DP-TAT-59 corresponding to the physiologic levels of serum estradiol in premenopausal women was sufficient to inhibit the estrogen-stimulated growth of MCF-7 tumors in mice. TAT-59 induced a dose-dependent increase in estrogen receptor levels in the MCF-7 tumors. In contrast, it prevented the estradiol (E2)-induced increase in progesterone receptor levels in a dose-dependent manner. Insulin-like growth factor 1 levels measured in the MCF-7 tumors significantly decreased in the TAT-59 alone group and in the no treatment group as compared with the E2 alone group. These results show the pronounced antiestrogenic action of TAT-59 on hormone-dependent MCF-7 tumors in athymic mice.

Animals↗
PubMed1994

Thyroid function in children with nephrotic syndrome.

The thyroid function of seven children with untreated nephrotic syndrome who had a normal serum creatinine concentration was compared with that of the same patients in remission and age-matched controls. There was a significant decrease in serum thyroxine (T4), tri-iodothyronine (T3) and thyroid-binding globulin (TBG) concentrations in untreated nephrotic children compared with the same patients in remission and age-matched controls. Most values for serum free T4, free T3 and thyroid-stimulating hormone (TSH) in the patients with nephrosis were within the normal range. However, the mean serum free T4 and free T3 concentrations were significantly (P < 0.05) lower in the untreated patients than in the same patients in remission, and the mean serum TSH concentrations were significantly (P < 0.05) higher in the untreated patients than in the same patients in remission. There were massive urinary losses of T4, T3, TBG, free T4 and free T3 in the untreated nephrotic children compared with the same patients in remission and age-matched controls. The daily urinary protein excretion showed a positive correlation with the urinary T4, T3, free T4, free T3 and TBG excretion. Furthermore, the urinary protein excretion showed a negative correlation with the serum T4, T3, free T4, free T3 and TBG levels. There was a negative correlation between serum albumin and serum TSH. These findings provide evidence of mild hypothyroidism in children with untreated nephrotic syndrome, partly because of losses of T4, T3, free T4, free T3 and TBG into the urine.

Child↗
PubMed1994

Comparison of the polymerase region of small round structured virus strains previously classified in three antigenic types by solid-phase immune electron microscopy.

We have used a reverse transcription-polymerase chain reaction with nested sets of primers to determine the nucleotide sequences of a 166 base pair segment of the RNA polymerase region of seven strains of small round structured viruses (SRSVs) from the United Kingdom. These SRSV strains were previously classified by solid-phase immune electron microscopy into three antigenic types--UK2, UK3 and UK4, which are comparable to the prototype strains Norwalk virus, Hawaii agent, and Snow Mountain agents, respectively. Based on their sequences, the seven strains from the United Kingdom could be divided into two groups. The first group included two strains of the UK2 type along with Norwalk virus and Southampton virus and the second group included three strains of UK3 and two strains of UK4 types. Viruses in the first group showed 75.3%-77.1% nucleotide and 89.1%-94.6% amino acid identity with Norwalk virus while those of the second group showed 60.8%-63.3% nucleotide and 67.3%-69.1% amino acid identity. Nucleotide and amino acid identity within the second group ranged between 91.6%-99.4% and 96.4%-100%, respectively. These results suggest that the SRSVs antigenically related with Norwalk virus, Hawaii agent, and Snow Mountain agent, can be classified into two genotypes on the basis of their sequences in the RNA polymerase region.

Adult↗
PubMed1994

Long-term results of microvascular decompression for trigeminal neuralgia with reference to probability of recurrence.

Sixty-one patients with trigeminal neuralgia who underwent microvascular decompression were analysed. Vascular compression of the trigeminal nerve root was found in all cases. The recurrence rate of pain in this series was 18% with an average follow-up of 80 months (range: 13 to 126 months). Ten patients developed recurrence of their trigeminal neuralgia during follow-up. Fifteen factors, including the clinical and operative findings in the pain-free patients versus the 10 patients with recurrence were analysed. Only the patients with venous compression singly or in combination with arteries were significantly related to recurrence. There was no relationship between recurrence and the duration of symptoms or the degree of compression. Based on vascular compression as the sole cause of TN, the results and interesting findings can not be explained. With reference to the hypothesis that vascular compression is only one of at least two causative factors for the development of trigeminal neuralgia, it is suggested that the intrinsic lesion in trigeminal neuralgia may be responsible for late recurrence.

Adult↗
PubMed1994

Early detection of successful coronary reperfusion based on serum myoglobin concentration: comparison with serum creatine kinase isoenzyme MB activity.

The usefulness of serum myoglobin (Mb) concentration for early detection of successful reperfusion was compared with that of creatine kinase isoenzyme MB (CKMB) activity in 49 patients with acute myocardial infarction. To determine accurately the time of reperfusion, we performed coronary angiography every 5 minutes during reperfusion therapy. Reperfusion was obtained in 32 patients (reperfused group) but not in 17 patients (nonreperfused group) until 60 minutes after the initiation of reperfusion therapy. Blood samples were taken before and 15, 30, and 60 minutes after the angiographic confirmation of reperfusion in the reperfused group. In the nonreperfused group, samples were taken before and 15, 30, and 60 minutes after the initiation of treatment. We calculated the Mb ratio (value after reperfusion or treatment initiation to value before) and CKMB ratio (value after to value before). When values > 2.4 for the Mb ratio or > 2.0 for the CKMB ratio were used as the criteria for reperfusion within 60 minutes after initiation of treatment, the sensitivities were 91% and 56% at 15 minutes after reperfusion, 97% and 84% at 30 minutes, and 100% and 100% at 60 minutes, respectively. For each ratio the specificity of detection was 100% at all times evaluated. Thus the Mb ratio accurately detected the success of reperfusion as early as 15 minutes after reperfusion and may be more useful than the CKMB ratio for detecting the success of reperfusion within 30 minutes.

Adult↗
PubMed1994

Increased expression of Na+/H+ exchanger in the injured renal tissues of focal glomerulosclerosis in rats.

The renal mRNA expression of Na+/H+ exchanger (NHE) and the effects of NHE inhibitor, amiloride, on renal injury were investigated in adriamycin (ADR)-induced glomerulosclerosis model in rats, which progressively developed extensive glomerulosclerosis and interstitial fibrosis. NHE-1 mRNA from the cortex of the ADR rats progressively increased at weeks 4 and 8 and then peaked at week 16, which paralleled with the degree of glomerular sclerosis and interstitial fibrosis. The interstitial fibrosis in the ADR-rats was prevented by a daily administration of amiloride. A simultaneous analysis of the effects of a high salt diet on NHE-1 mRNA expression or renal injury was performed in the ADR rats at weeks 2 and 8. Renal or glomerular hypertrophy was observed in the control or ADR rats fed an 8% NaCl diet at week 2 and 8 compared to a 1% NaCl diet, while the NHE-1 mRNA expression was not up-regulated by an 8% NaCl diet at week 2. At week 8, the NHE-1 mRNA expression or glomerulosclerosis and interstitial fibrosis were enhanced in the ADR rats fed an 8% NaCl diet compared to a 1% NaCl diet. This histological aggravation by an 8% NaCl diet was prevented by a daily administration of amiloride but not by furosemide. In conclusion, the increased NHE-1 mRNA expression and the preventive effects of amiloride on the renal lesions suggest a potential importance of NHE in the progressive process of ADR-nephropathy. The high salt diet had a hypertrophic and destructive effect on kidney or glomeruli in the ADR rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1994

TGF-beta 1 in glomerulosclerosis and interstitial fibrosis of adriamycin nephropathy.

The role of transforming growth factor-beta 1 (TGF-beta 1) for renal injury was investigated in the chronic model of progressive renal disease in rats induced by the injection of adriamycin. The renal cortical tissues were sampled at weeks 4, 8 and 16 for histological examination, either cortical or glomerular cell culture, and RNA extraction. A progressive increase in fibronectin synthesis was found in metabolically labeled cortical or glomerular culture at week 8 or 16, correlating with the degree of glomerulosclerosis and interstitial fibrosis. TGF-beta bioassay (mink lung epithelial cell assay) showed a progressive increase in latent TGF-beta secretion from cortex and glomeruli, while the amount of active TGF-beta was small. The peak of latent TGF-beta levels at week 16 coincided with the intense TGF-beta 1 staining of inflammatory cells dispersed in the interstitium and glomeruli. Northern blotting demonstrated the difference in the mRNA expression patterns of TGF-beta 1 and latent TGF-beta 1 binding protein (LTBP) in the cortex. TGF-beta 1 mRNA was constantly high throughout the experiment, while LTBP mRNA increased progressively and reached a peak at week 16. Furthermore, mRNA levels of fibronectin, procollagen alpha 2(I), and TGF-beta type II and type III receptors increased progressively in a similar pattern to the renal histological changes. These temporal and spacial relationships between the renal histological changes and the increased expression of TGF-beta 1 and TGF-beta receptors may thus suggest that TGF-beta 1 plays an important role in the process of the renal fibrosis and sclerosis.

Animals↗
PubMed1994

Stimulation of the synthesis of histamine and putrescine in mice by a peptidoglycan of gram-positive bacteria.

To clarify the base of in vivo biological activities of peptidoglycans of Gram-positive bacteria, the effects of a polysaccharide peptide of Staphylococcus epidermidis peptidoglycan (SEPS) on the synthesis of histamine and putrescine in BALB/c mice were examined and compared with those of a lipopolysaccharide (LPS or endotoxin) of Gram-negative bacteria. Within a few hours after its injection into BALB/c mice, SEPS induced histidine decarboxylase (HDC), the enzyme forming histamine, in the liver, lung, spleen and bone marrow, and ornithine decarboxylase (ODC), the enzyme forming putrescine, in the tissues except for the lung. SEPS induced HDC activity even in mast cell-deficient mice and in nude mice. These effects of SEPS were essentially the same as those of LPS. However, the dosage of SEPS capable of inducing HDC and ODC was much higher (100 to 1,000 times) than that of LPS. We have reported that C3H/HeN mice are resistant to SEPS in producing acute arthritis, and their productions of IL-1 and prostaglandin E2 are less than BALB/c mice sensitive to producing acute arthritis. In the present study, it was also found that C3H/HeN mice were markedly resistant to SEPS in inducing HDC activity.

Animals↗
PubMed1994

A study of parkinsonism in multiple system atrophy: clinical and MRI correlation.

We investigated clinical and MRI correlation in 18 patients with clinically-diagnosed multiple system atrophy (MSA) and 16 age-matched controls, using 1.5 T magnetic resonance imaging (MRI). We evaluated the severity of parkinsonism in each MSA patient. In assessing the MRI findings, we examined three parameters quantitatively: width of the pars compacta of the substantia nigra (SNc); putaminal hypointensity on T2-weighted images; and putaminal atrophy. As in previous studies, SNc width was narrowed and the putaminal signal intensity was decreased in patients with MSA compared with controls. The clinical severity of parkinsonism did not correlate significantly with the SNc width or the score of putaminal hypointensity in MSA. However, not only did putaminal atrophy occur, but correlated well with the severity of parkinsonism in MSA. A significant correlation could not be established between narrowing of SNc and shrinkage of the putamen. These findings suggest that putaminal atrophy is associated with the clinical manifestations of parkinsonism and do not support the hypothesis that transsynaptic degeneration occurs in MSA.

Adult↗
PubMed1994

Application of PCR to detect Norwalk virus in fecal specimens from outbreaks of gastroenteritis.

Norwalk virus (NV) and other small round-structured viruses (SRSVs) are frequent causes of gastroenteritis outbreaks. The recent cloning and sequencing of the NV genome has made it possible to detect NV and Norwalk-related viruses from fecal specimens by reverse transcription (RT)-PCR. We applied this technique to the examination of a total of 139 fecal specimens from 19 outbreaks characterized by NV serology, including 56 samples from 7 NV outbreaks, 36 from 6 Norwalk-related virus outbreaks, and 47 from 6 outbreaks with SRSVs visualized by electron microscopy that were serologically unrelated to NV. Three primer pairs were evaluated: two pairs in the polymerase region of NV and one pair near the 3' end of the genome. When one set of primers (primer pair 51-3) from the polymerase region was used, 40% of all samples were positive by RT-PCR and specimens from the NV outbreaks were more likely to be positive (64%) than those from outbreaks associated with Norwalk-related viruses (44%) or SRSVs (8%). To determine the relationship of the outbreak strains to NV, we compared the sequences of a 145-base portion of the polymerase gene from 10 specimens obtained from five different outbreaks characterized as NV by serology. No two outbreak strains had the same sequence in this 145-base portion of the polymerase gene, and the identities of the nucleotide and amino acid sequences of these products compared with the sequences of the corresponding region of NV ranged from 62 to 79% and 69 to 90%, respectively. Because of sequence diversity in the polymerase region, the successful application of RT-PCR to investigations of outbreaks of suspected NV-associated gastroenteritis will depend on the use of either multiple primer pairs or primers made against regions of the genome that are more conserved.

Amino Acid Sequence↗
PubMed1994

Sequence diversity of small, round-structured viruses in the Norwalk virus group.

We have determined the nucleotide sequences of a highly conserved region of the RNA-dependent RNA polymerase of the prototype Snow Mountain agent (SMA) and of four other small, round-structured viruses (antigenically Norwalk virus [NV]-like or SMA-like) following reverse transcription-PCR amplification of viral RNA obtained from human stools. The stool samples were either from volunteers administered SMA or from sporadic cases and outbreaks of gastroenteritis that occurred in Japan and the United Kingdom between 1984 and 1992. The GLPSG and YGDD RNA polymerase motifs were in the proper locations in the sequences of the five SRSVs, but each sequence was distinct from the 8FIIa prototype NV sequence and from each other. Analysis of the sequences and reactivities in a new NV antigen enzyme-linked immunosorbent assay showed that the five viruses could be divided into two groups (serogroups) with NV and SMA, respectively, being the prototypes. The sequences of the capsid region and a nonstructural region (2C) were determined from one strain from each group. One virus (SRSV-KY-89/89/J), isolated in Japan and antigenically similar to the prototype NV (isolated 21 years earlier in Ohio), showed a remarkable level of sequence similarity to NV. KY-89 and the 8FIIa NV showed 87.2% nucleotide similarity over 2,516 continuous nucleotides amounting to 96 to 98.9% amino acid similarity in three distinct domains in two open reading frames. Between the prototype SMA and NV, the polymerase region showed 63% nucleotide and 59% amino acid similarity, respectively. Two other antigenically SMA-like isolates (SRSV-925/92/UK and SRSV-OTH-25/89/J), from the United Kingdom and Japan, showed 80% nucleotide and 88 to 92% amino acid similarity in the polymerase region to the prototype SMA isolated 16 and 13 years earlier in the United States. The capsid region of the antigenically SMA-like OTH-25 virus showed 53% nucleotide and 65% amino acid similarity to the prototype NV capsid region. Domains of sequence diversity and conversation were identified within the capsid protein of these two distinct prototype serotypes of virus. These results indicate that NV-like and SMA-like agents are still circulating, and sequence comparisons will be useful to identify and classify distinct viruses in the NV group.

Base Sequence↗
PubMed1994

Asbestos exposure stimulates pleural mesothelial cells to secrete the fibroblast chemoattractant, fibronectin.

Parietal pleural plaques and visceral pleural fibrosis are well-recognized stigmata of occupational asbestos exposure. However, their pathogenesis is poorly understood. Conceivably, phagocytosis of asbestos fibers by pleural mesothelial cells may stimulate the recruitment of fibroblasts to sites of asbestos-induced pleural injury. To test this hypothesis, rat parietal pleural mesothelial cells were cultured for 6 to 96 h with or without crocidolite or chrysotile asbestos fibers (concentration range, 2 to 100 micrograms/cm2). Asbestos fibers were actively phagocytosed by pleural mesothelial cells and were incorporated within phagosomes. Conditioned medium was assayed for chemotactic activity toward RL-87 rat lung fibroblasts and for fibronectin immunoreactivity. The effects of asbestos were compared with those of alpha-cristobalite (which is strongly fibrogenic), alpha-quartz (a less fibrogenic particulate), and carbonyl iron (a nonfibrogenic agent). Both types of asbestos stimulated the secretion of fibroblast chemoattractant activity by pleural mesothelial cells in a time-dependent manner. This effect peaked at 96 h in cultures containing 4 micrograms/cm2 of asbestos (P < 0.001). alpha-Cristobalite also enhanced the secretion of the mesothelial cell-derived chemoattractant, an effect that was maximal at a concentration of 20 micrograms/cm2 (P < 0.001). Furthermore, crocidolite, chrysotile, and alpha-cristobalite stimulated pleural mesothelial cell fibronectin synthesis. In contrast, alpha-quartz and carbonyl iron particles had no noticeable effect on either immunoreactive fibronectin secretion or chemoattractant release by pleural mesothelial cells. The ability of asbestos fibers and alpha-cristobalite particles to stimulate the secretion of the fibroblast chemoattractant, fibronectin, by pleural mesothelial cells may have relevance to the induction of pleural injury by fibrogenic particulates.

Animals↗