Biomedical subjects

T Takimoto

Publications and source records attributed to T Takimoto.

At least 37 records · Page 2Linked to original sources

PubMed1998

Biopsy sites suitable for the diagnosis of Helicobacter pylori infection and the assessment of the extent of atrophic gastritis.

OBJECTIVES: We performed this study to determine which biopsy sites in the stomach are suitable for the diagnosis of Helicobacter pylori infection and the assessment of the extent of atrophic gastritis. METHODS: Endoscopy was performed in 76 H. pylori-positive patients with histologically confirmed chronic gastritis. Biopsies were taken from the following six sites: the lesser curvatures of the mid-antrum (site 1), the angulus (site 2), the middle body (site 3), and the greater curvatures of the mid-antrum (site 4), the angulus (site 5), and the middle body (site 6) of the stomach. The extent of atrophic gastritis was assessed endoscopically as well as histologically, and patients were classified into five groups according to its extent. H. pylori status was assessed histologically. The histological severity of inflammation, activity, atrophy, and intestinal metaplasia was assessed according to the Updated Sydney System. The grades of these items were compared among the six biopsy sites in each group of patients. RESULTS: Site 6 was most reliable for the diagnosis of H. pylori infection, and site 4 was suitable for examining the status of H. pylori colonization in the antrum. Site 1, site 3, and site 6 were suitable for the assessment of the extent of atrophic gastritis. CONCLUSIONS: Our results indicate that for an accurate diagnosis and assessment, biopsies should be taken from the following four sites: the lesser curvatures of the mid-antrum (site 1) and middle body (site 3), and the greater curvatures of the mid-antrum (site 4) and middle body (site 6) of the stomach.

Adult↗

PubMed1998

Cytoplasmic domain of Sendai virus HN protein contains a specific sequence required for its incorporation into virions.

In the assembly of paramyxoviruses, interactions between viral proteins are presumed to be specific. The focus of this study is to elucidate the protein-protein interactions during the final stage of viral assembly that result in the incorporation of the viral envelope proteins into virions. To this end, we examined the specificity of HN incorporation into progeny virions by transiently transfecting HN cDNA genes into Sendai virus (SV)-infected cells. SV HN expressed from cDNA was efficiently incorporated into progeny Sendai virions, whereas Newcastle disease virus (NDV) HN was not. This observation supports the theory of a selective mechanism for HN incorporation. To identify the region on HN responsible for the selective incorporation, we constructed chimeric SV and NDV HN cDNAs and evaluated the incorporation of expressed proteins into progeny virions. Chimera HN that contained the SV cytoplasmic domain fused to the transmembrane and external domains of the NDV HN was incorporated to SV particles, indicating that amino acids in the cytoplasmic domain are responsible for the observed specificity. Additional experiments using the chimeric HNs showed that 14 N-terminal amino acids are sufficient for the specificity. Further analysis identified five consecutive amino acids (residues 10 to 14) that were required for the specific incorporation of HN into SV. These residues are conserved among all strains of SV as well as those of its counterpart, human parainfluenza virus type 1. These results suggest that this region near the N terminus of HN interacts with another viral protein(s) to lead to the specific incorporation of HN into progeny virions.

Amino Acid Sequence↗

PubMed1998

A follow-up study of atrophic gastritis and intestinal metaplasia after eradication of Helicobacter pylori.

BACKGROUND: Opinions differ as to whether atrophic gastritis and intestinal metaplasia (IM) improve after Helicobacter pylori eradication. We investigated the change of the severity of atrophy and IM after H. pylori eradication. MATERIALS AND METHODS: Twenty H. pylori-positive patients with histologically confirmed atrophic gastritis received anti-H. pylori therapy and achieved eradication. They were followed for 12-33 months (median 17 months) after the therapy. Biopsies were taken from the lesser and greater curvatures of the mid-antrum and middle body, and the incisura angularis of the stomach. The state of H. pylori infection was assessed histologically (Giemsa stain). Histological severity of atrophy and IM was graded according to the Updated Sydney System and scored on a 0-3 scale. The scores of atrophy and IM were compared between before and after the therapy (at the end of follow-up). RESULTS: No significant difference was found in the scores of antral or body atrophy between before and after the therapy. Scores of antral IM increased after the therapy, whereas those of body IM did not change significantly. Development of IM in the whole stomach was found in three of seven patients who had no IM before the therapy. All of them were male smokers and drinkers. In contrast, complete regression of IM was not found. CONCLUSIONS: Our results cast doubt on the reversibility of atrophy and IM after H. pylori eradication. Development of IM could be found in some of patients with atrophy even after H. pylori eradication.

Adult↗

PubMed1997

Elevated expression of the human parainfluenza virus type 1 F gene downregulates HN expression.

Interactions involved in the expression of parainfluenza glycoproteins were examined by expressing cDNA clones of the HN and F genes from human parainfluenza virus type-1 (hPIV1) or Sendai virus (SV) in recombinant Semliki Forest virus (recSFV) or vaccinia-T7 expression vectors. We found that expression of a cloned F protein gene of hPIV1 resulted in downregulation of the HN proteins of hPIV1 or SV. Compared to the amount of HN expressed in the absence of F, coexpression of HN and F led to about 70% reduction in HN. This reduction of HN was observed in both total cell lysates and in protein localized on the cell surface. In contrast to hPIV1 F, SV F did not suppress the expression of HN. Northern blot analysis indicated that similar levels of HN mRNA accumulated in the absence or presence of hPIV1 F. The reduction of HN protein expression by hPIV1 F was detectable after as little as a 10-min labeling period, suggesting that downregulation occurred at the level of translation or at an early stage of protein folding. In hPIV1-infected cells, the amount of F protein synthesized was only about 15% of that of HN, whereas SV F is expressed at high levels. When the level of F in hPIV1-infected cells was artificially increased by recSFV, HN expression was suppressed. The reduction of F protein production in hPIV1-infected cells was regulated at the level of transcription. Characterization of mRNAs produced in hPIV1-infected cells showed that only 20% of the hPIV1 F mRNAs were monocistronic transcripts; 80% were bicistronic M-F readthrough mRNAs. Because proteins are suggested to be synthesized from only the first cistron of bicistronic mRNA in paramyxovirus (T. C. Wong and A. Hirano (1987) J. Virol. 61, 584-589), production of F protein is likely suppressed by transcriptional regulation in hPIV1-infected cells. These results suggest that F is capable of downregulating the synthesis of HN, but that this is normally prevented in hPIV1-infected cells by suppression of F protein synthesis by transcriptional regulation.

Animals↗

PubMed1997

Comparison of ranitidine and lansoprazole in short-term low-dose triple therapy for Helicobacter pylori infection.

AIM: To evaluate the efficacy and safety of two 1-week low-dose triple-therapy drug regimens involving antisecretory drugs for Helicobacter pylori infection. 99 patients with H. pylori infection were treated with either lansoprazole or ranitidine used together with clarithromycin and metronidazole. METHODS: The drug combination and administration periods in the proton pump inhibitor group were lansoprazole 30 mg o.m., clarithromycin 200 mg b.d. and metronidazole 250 mg b.d., all given for 7 days (LCM group). The ranitidine group received ranitidine 150 mg b.d., clarithromycin 200 mg b.d. and metronidazole 250 mg b.d. also for 7 days (RCM group). The presence or absence of H. pylori was determined from gastric biopsy specimens taken from both the antrum and the body, by smear, culture and tissue section (Giemsa stain). Cure was defined as failure to find evidence of H. pylori infection 4 weeks after antimicrobial therapy had ended. RESULTS: The cure of H. pylori infection was 88% in the LCM group (44 of 50; 95% confidence interval (CI) = 79-97%) and 92% in the RCM group (45 of 49; 95% CI = 84-99%). The incidence of adverse events was 16% and 18% for the two groups, respectively. CONCLUSIONS: No significant differences in cure rate and safety profiles were noted between the two regimens, suggesting that moderate acid inhibition using an H2-blocker is sufficient to achieve optimal H. pylori eradication.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1997

The efficacy and safety of one-week triple therapy with lansoprazole, clarithromycin, and metronidazole for the treatment of Helicobacter pylori infection in Japanese patients.

BACKGROUND: The aim of this study was to evaluate the efficacy and tolerability of 1-week, low-dose triple therapy with lansoprazole, clarithromycin, and metronidazole (LCM) for the cure of H. pylori infection and to establish the adequate dosage of a new triple therapy for Japanese patients. MATERIALS AND METHODS: One hundred four H. pylori-positive Japanese patients were assigned alternatively to one of two groups: one to receive either 30 mg lansoprazole once in the morning, 200 mg clarithromycin twice daily, and 250 mg metronidazole twice daily for 1 week (LCM1; n = 52); the other to receive 30 mg lansoprazole once in the morning, 200 mg clarithromycin twice daily, and 500 mg metronidazole twice daily for 1 week (LCM2; n = 52). H. pylori infection was assessed by smear, culture, and histological assessment (Giemsa stain) performed before and 4 weeks after cessation of the therapy. RESULTS: The overall cure rates of H. pylori infection were 92.3% (48 of 52; 95% confidence interval (CI), 85% to 100%) in LCM1 and 92.3% (48 of 52; 95% CI, 85% to 100%) in LCM2. The cure rates in the patients without prior treatment were 95.7% (44 of 46; 95% CI, 89%-100%) in LCM1 and 95.7% (45 of 47; 95% CI, 89%-100%) in LCM2. Minor side effects were observed in 7.7% of LCM1 and 9.6% of LCM2, respectively. CONCLUSION: The LCM1 regimen consisting of 30 mg lansoprazole once daily, 200 mg clarithromycin twice daily, and 250 mg metronidazole twice daily (the regular doses in ordinary use in Japan) is a highly effective and safe regimen for Japanese patients. LCM1 as a new triple therapy is a promising regimen for the first-line treatment of H. pylori infection in Japanese patients.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1996

Gastritis in the Japanese stomach.

Endoscopic studies of Japanese patients with gastritis have revealed the existence of an endoscopic atrophic border that marks the transition between non-atrophic gastritis and atrophic gastritis, and between fundic glands and pyloric glands. Marked changes in cell type, gastritis activity, atrophy and density of Helicobacter pylori infection occur across this border. Gastritis appears to extend from the antrum to the corpus more quickly in Japanese patients than in patients from other populations. Infection with H. pylori may be an important factor influencing the rate of progression of gastritis in Japanese patients.

Atrophy↗

PubMed1996

Distribution of inflammation and atrophy in the stomach of Helicobacter pylori-positive and -negative patients with chronic gastritis.

OBJECTIVES: To investigate the extent of inflammation and atrophy in the stomach of Helicobacter pylori-positive and -negative patients with chronic gastritis. METHODS: Endoscopy with biopsies from the lesser curvatures of the antrum, angulus, middle body, and the greater curvature of the middle body of the stomach was performed in 59 patients with histologically confirmed chronic gastritis. The extent of atrophic gastritis was assessed endoscopically as well histologically. H. pylori status was assessed by histology as well as enzyme-linked immunosorbent assay. The histological severity of chronic and acute inflammation, glandular atrophy, and intestinal metaplasia was assessed according to the Sydney system. RESULTS: In H. pylori-positive patients, H. pylori was evenly distributed throughout the stomach when the extent of atrophic gastritis was limited to the antrum and the lesser curvature of the body, but disappeared from the antrum of patients with more extensive atrophic gastritis. The severity of acute and chronic inflammation at the greater curvature of the body increased with the extension of atrophic gastritis. In H. pylori-negative patients, the severity of chronic inflammation at the greater curvature of the body was significantly higher in patients with extensive atrophic gastritis than in those with a lesser extent of atrophic gastritis. CONCLUSION: At the greater curvature of the body, the development of atrophy is closely associated with the increase in the severity of inflammation, which is more marked in H. pylori-positive patients.

Adolescent↗

PubMed1996

Simple 13C-urea breath test with infra-red spectrophotometer.

When mass spectrophotometric analysis is used for the 13C-urea breath test to assess H. pylori infection, it is costly, complicated, and time-consuming. To overcome these disadvantages, we utilized an infra-red spectrophotometer as a substitute for the mass spectrophotometer. A total of 153 patients (181 tests) analyzed with peptic ulcers or non-ulcer dyspepsia were investigated. Breath samples were collected 15 min after ingestion of 13C-urea (100 mg in 30 ml water). An infra-red spectrophotometer was used to determine the concentration of 13CO2 in the expirate. The 13CO2/12CO2 ratio was also measured by mass spectrophotometry to compare results with those of infra-red spectrophotometric analysis. Direct detection of H. pylori was qualified in biopsy specimens. Of the 181 biopsies, 138 were positive for H. pylori infection and 43 were negative. With the urea breath test, the mean value in the positive group was significantly higher than that in the negative group (0.062 +/- 0.044 vs 0.011 +/- 0.014, respectively). The cut-off level, 0.01, was determined as delta 13C atom %. The sensitivity of infra-red spectrophotometry was 97.8% (135/138) and specificity was 74.4% (32/43). There was an extremely high coefficient of correlation (r = 0.996) between mass and infra-red photometric analysis. Infra-red spectrometry appears to have great potential not only for diagnosing H. pylori infection but also for assessing treatment results. Its advantages include technical simplicity, cost-effectiveness, and high accuracy.

Breath Tests↗

PubMed1996

Efficacy of clarithromycin in eradicating Helicobacter pylori.

We reviewed reports on the efficacy of clarithromycin in eradicating Helicobacter pylori. Reports on dual and 1-week triple therapy that included clarithromycin were analyzed to assess the eradication rates of H. pylori infection. Dual therapy with clarithromycin and a proton pump inhibitor achieved eradication rates of 38%-83%, and 1-week triple therapy with omeprazole, clarithromycin, and other antibiotics achieved eradication rates, of 80%-96%. The incidence of side effects with all regimens was low. Clarithromycin is useful for treatment of H. pylori infection. One-week triple therapy that includes clarithromycin and a proton pump inhibitor effectively eradicates H. pylori.

Anti-Bacterial Agents↗

PubMed1996

Endoscopic topical therapy for the treatment of Helicobacter pylori infection.

We modified a novel topical therapeutic method for the treatment of Helicobacter pylori infection to increase its effectiveness and tolerability. Sixty-six patients (with nonulcer dyspepsia, inactive ulcer, or active ulcer) were given lansoprazole (30 mg, h.s.) and pronase (18,000 tyrosine units, b.i.d.) orally for 2 days before the topical therapy. One hundred milliliters of 7% sodium bicarbonate solution containing bismuth subnitrate, amoxicillin, metronidazole (at two different regimens), and pronase was instilled into the stomach through an endoscope. A double-lumen tube with a balloon at the tip was inserted into the duodenum along with the endoscope. The balloon was inflated with 25 ml of air and was lodged postbulbarly. The solution was kept in the stomach for 2 h, and the patient's position was changed every 15 min from the sitting to the supine, prone, and right lateral position, each position being maintained twice, to expose the entire gastric mucosa. The solution was aspirated at the end of the procedure. H. pylori infection was cured in 16/22 (72.7%) of patients with nonulcer dyspepsia, in 21/26 (80.7%) of patients with inactive ulcer, and in 1/18 (5.6%) patients with active ulcer. H. pylori eradication was confirmed 4 weeks after the therapeutic procedure by smear, culture, and histology of antral and corpus biopsy specimens. Side effects (loose stools) were observed in two patients only, and one patient had loss of appetite. These effects were transient. This endoscopic topical therapy for H. pylori infection is a safe, effective, and well tolerated procedure. With further modifications of the drug regimens and the method itself, this procedure could be of interest as anti-H. pylori therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1995

A single amino acid changes enhances the fusion promotion activity of human parainfluenza virus type 1 hemagglutinin-neuraminidase glycoprotein.

Clinical isolates of human parainfluenza virus type 1 in our laboratory were found to induce significantly different degrees of syncytium formation in CV-1 cells. Sequence analysis of high- and low-fusion strains suggested that the hemagglutinin-neuraminidase (HN) protein was responsible for the differences in fusion activity. We exploited the strain differences to define the specific amino acid residues of the HN protein which were responsible for the low and high fusion activities. The HN proteins of the two low-fusogenic strains 8389 and 45785, and the highly fusogenic strain C35, were expressed in HeLa T4+ cells and their fusion promotion activities were compared. When coexpressed with C35 F, HNs from the low-fusogenic viruses were associated with much lower fusion activity than was C35 HN, suggesting that the HN proteins modified the fusogenicity of the viruses. To identify the region of the HN protein responsible for this difference, we constructed a series of chimeric HN cDNAs combining 8389 and C35 sequences. All chimeric HNs that contained C35 sequence in the central 36% of the protein exhibited high fusion promotion activity. Further analysis by site-directed mutagenesis showed that a single Asn-to-Lys substitution at position 242 converted 8389 HN to a highly fusion-promoting molecule. Thus, the globular head of the HN molecule is involved in fusion promotion activity.

Amino Acid Sequence↗

PubMed1995

Efficacy of lansoprazole in eradication of Helicobacter pylori.

Fifty-eight Helicobacter pylori-positive ulcer patients received omeprazole 20 mg (n = 15), or lansoprazole 30 mg (n = 23), lansoprazole 60 mg (n = 13), or E3810 20 mg (n = 7) q.d. Another 63 H. pylori-positive ulcer patients received lansoprazole and clarithromycin for 2 weeks. Patients received lansoprazole 30 mg and clarithromycin 400 mg (group 1, n = 22), lansoprazole 30 mg and clarithromycin 800 mg (group 2, n = 12), or lansoprazole 60 mg and clarithromycin 800 mg (group 3, n = 29). Neither proton pump inhibitor (PPI) was capable of eradication by monotherapy, but the clearance rates in the lansoprazole group were 60.9 and 69.2%, which were higher than those for omeprazole (p < 0.05). In the dual therapy, eradication rates were 50, 50, and 72.4% in groups 1, 2, and 3, respectively. Minor side effects were observed in one case each in groups 1 and 3. Lansoprazole monotherapy proved more efficacious than omeprazole monotherapy, but it was unable to eradicate H. pylori. Dual therapy with lansoprazole 60 mg and clarithromycin 800 mg was an efficacious and safe regimen for H. pylori eradication in this study.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1995

A 1-h topical therapy for the treatment of Helicobacter pylori infection.

OBJECTIVE: A novel topical therapeutic methodology for the treatment of Helicobacter pylori infection was developed and studied in 25 patients with H. pylori to evaluate safety and efficacy. METHODS: The patients had been given lansoprazole (30 mg, hs) orally and pronase (18,000 tyrosine units, b.i.d.) for the 2 days before topical therapy. One hundred milliliters of solution with 80 ml of 7% sodium bicarbonate and 20 ml of contrast medium meglumine sodium amidotrizoate containing bismuth subnitrate (1 g), amoxicillin (2 g), metronidazole (1 g), and pronase (36,000 tyrosine units) were instilled into the stomach through a nasally introduced 16-Fr intestinal tube with a balloon at its radiopaque tip, which was inflated with approximately 25 ml of air and lodged postbulbarly at the superior duodenal angle under fluoroscopy, thus preventing leakage of the solution distally into the jejunum. The solution was kept in the stomach for 1 h, and the patient's position was changed every 15 min from the sitting to the supine, prone, and right lateral position to expose the entire gastric mucosa. The solution was suctioned at the end of the procedure. RESULTS: H. pylori infection was successfully cured in 24 (96%) patients, confirmed 4 wk after the therapeutic procedure by negative smear, culture, and histology of the antral and corpus biopsy specimens. No side effects were observed except for loose stools in one case. CONCLUSION: This 1-h topical therapy is a safe, effective, and well tolerated procedure for the treatment of H. pylori infection. With further improvements and modifications of the method itself, as well as of the drug regimens, this method may become a highly efficient modality for anti-H. pylori therapy.

Adult↗

PubMed1995

Dual therapy with lansoprazole and clarithromycin for eradication of Helicobacter pylori.

AIM: To evaluate the eradication of Helicobacter pylori by therapy with a combination of 60 mg lansoprazole and 800 mg clarithromycin. PATIENTS AND METHODS: In an open therapeutic trial, 30 H. pylori-positive patients with active ulcer disease took 30 mg lansoprazole twice a day and 400 mg clarithromycin twice a day for the first 2 weeks, followed by 30 mg lansoprazole once a day for 4-6 weeks. Endoscopy was performed both before and at the end of therapy, and 4 weeks after the end of the therapy. H. pylori was detected by using a combination of smear, culture and tissue sections. RESULTS: Complete pain relief occurred within 3 days in all patients and all ulcers were healed by the end of the therapy. The H. pylori clearance rate was 83.3% and the eradication rate was 73.3%. A minor side effect (metallic taste) was reported by only one patient (3.3%). CONCLUSIONS: Therapy with a combination of 60 mg lansoprazole and 800 mg clarithromycin is efficacious in the eradication of H. pylori and has the advantage of a low incidence of side effects and quick pain relief for patients with active ulcers.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1995

Helicobacter pylori detected deep in gastric glands: an ultrastructural quantitative study.

To determine the presence of Helicobacter pylori deep in the gastric glands and in the parietal cell canaliculi, biopsied specimens from 15 patients were observed by electron microscopy. In the specimens, 818 H. pylori and 1,846 parietal cells were detected. Most of the H. pylori (93.9%, 768/818) were present on the mucosal surface. However, a few organisms (50/818, 6.1%) were detected deep in the mucosa. The mean number of H. pylori per specimen was 2.13 (32/818, 3.9%) and 1.20 (18/818, 2.2%), deep in the gland and in the parietal cell canaliculi, respectively. All appeared morphologically intact. Although the combination of culture and histology from biopsy tissues is usually used for isolation of H. pylori in most laboratories, such organisms are considered difficult to detect with conventional methods and to dislodge with antimicrobial therapy. Therefore, H. pylori present deep in the mucosa are suggested to be one of the factors in recrudescence after eradication therapy. In addition, H. pylori in the parietal cell canaliculi may affect parietal cell function or alter gastric physiology.

Adult↗

PubMed1994

Regions on the hemagglutinin-neuraminidase proteins of human parainfluenza virus type-1 and Sendai virus important for membrane fusion.

To study the contributions of the hemagglutinin-neuraminidase (HN) and the fusion (F) glycoproteins in virus-induced membrane fusion, the HN and F proteins of human parainfluenza virus type-1 (hPIV-1) and Sendai virus (SV) were expressed in HeLa T4+ cells using the vaccinia virus-T7 RNA polymerase transient expression system. Expression of F protein alone did not induce cell fusion. However, coexpression of homologous F and HN proteins resulted in extensive syncytium formation by hPIV-1 or SV glycoproteins, which supports the proposal that both the F and HN glycoproteins are necessary for membrane fusion. To investigate the function of HN in membrane fusion, we coexpressed heterologous combinations of the HN and F proteins of hPIV-1 and SV. No fusion was observed when SV HN and hPIV-1 F proteins were coexpressed. In contrast, the coexpression of hPIV-1 HN and SV F induced extensive cell fusion. These results suggest that specific interaction between HN and F is required to induce membrane fusion. To locate regions that are essential to the fusion promoting activity, chimeric HN proteins of SV and hPIV-1 were constructed. The chimeric proteins coexpressed with the SV or hPIV-1 F proteins indicated that some regions in the middle 62% of HN contribute to the fusion-promoting activity. To determine the role of the transmembrane region of HN on fusion-promoting activity, mutant HN proteins were expressed and their biological activities examined. Mutation of hPIV-1 HN at residue 55 from cysteine to tryptophan did not affect cell binding, neuraminidase activities, or homooligomer formation, but did result in the loss of cell fusion activity. The mutation of the same cysteine residue to glycine retained the fusion-promoting activity, suggesting that a sulfhydryl moiety is not specifically required at position 55, but the structure of the residue that occupies the position is important in fusion-promoting activity.

HN Protein↗

PubMed1994

Viral cross-reactivity and antigenic determinants recognized by human parainfluenza virus type 1-specific cytotoxic T-cells.

To obtain information relevant to vaccination against human parainfluenza virus type 1 (hPIV-1), cytotoxic T-lymphocyte (CTL) responses to individual viral components were tested. The CD8-positive T-cell fraction was first enriched from human, adult PBL and grown for several passages in the presence of hPIV-1-infected stimulator cells. T-cell lines were then tested for CTL activity toward hPIV-1 and toward the related viruses hPIV-3 and Sendai virus (the murine parainfluenza type 1 virus). All tested cultures which responded to hPIV-1 also responded to hPIV-3 and Sendai virus, demonstrating sequence conservation between all three viruses among major antigenic determinants for CTL. Specificity for particular viral components was defined using recombinant vaccinia viruses expressing individual proteins from either mouse or human parainfluenza type 1 viruses. Strong CTL responses toward hemagglutinin-neuraminidase, phosphoprotein, and nucleoprotein (NP) were demonstrated. The testing of vaccinia constructs expressing truncated proteins then showed that there were multiple CTL determinants within NP. Several T-cell lines from one donor recognized an NP peptide (amino acids 321-336) conserved between the hPIV-1 and Sendai virus. In total, the results demonstrated that the human CTL response is directed to multiple determinants within several distinct hPIV-1 proteins.

Adult↗