Biomedical subjects

M Chiba

Publications and source records attributed to M Chiba.

At least 73 records · Page 4Linked to original sources

PubMed2000

Immunohistochemical analysis of the distribution of measles related antigen in the intestinal mucosa in inflammatory bowel disease.

BACKGROUND: Measles virus is implicated in the aetiology of Crohn's disease. This measles hypothesis is mainly supported by immunohistochemical findings that the measles related antigen is present in the intestine of patients with Crohn's disease. Recently we isolated this antigen from the intestine of a patient with Crohn's disease using a molecular cloning technique and produced the monoclonal antibody against it (designated 4F12). AIM: To discover whether the measles related antigen is uniquely present in Crohn's disease. SUBJECTS/METHODS: Colonic mucosa samples from 20 patients with Crohn's disease, 20 with ulcerative colitis, 11 with non-inflammatory bowel disease (IBD) colitis, and nine controls were immunohistochemically stained with the anti-measles monoclonal antibody 4F12. The numbers of positive cells, the ratio of positive cells to nucleated cells, and the staining intensity of the positive cells were compared. Furthermore, the distribution of the measles antigen in other human organs was examined. RESULTS: Both the number of positive cells and the ratio of positive cells to nucleated cells were significantly increased in Crohn's disease, ulcerative colitis, and non-IBD colitis compared with controls (p<0.05) but were similar among the three disease groups. The staining intensity of the positive cells was also similar among the three disease groups. Small numbers of positive cells were observed in the oesophagus, stomach, duodenum, jejunum, and lung. CONCLUSIONS: The presence of the measles related antigen in the colonic mucosa was not unique to Crohn's disease. These results, together with the observation that such a measles related antigen was derived from host protein, do not support the hypothesis that measles virus causes Crohn's disease.

Adolescent↗

PubMed2000

Variations in vitamin D-binding protein (group-specific component protein) are associated with fasting plasma insulin levels in Japanese with normal glucose tolerance.

The locus of the vitamin D-binding protein (DBP; also known as group-specific component protein or Gc) gene, chromosome 4q12, has been reported to be associated with glucose metabolism in several ethnic groups, including Pima Indians. We have recently reported the association of the DBP genotype with type 2 diabetes mellitus in Japan. The aim of this study was to investigate whether genetic variations of DBP have any influence on glucose metabolism without secondary effects of hyperglycemia or diabetes mellitus using 82 Japanese with normal glucose tolerance. The variations of the DBP gene (Gc 1F, 1S, and 2) were determined by PCR-restriction fragment length polymorphism. Fasting plasma insulin concentration and homeostasis model assessment, an index of insulin resistance, were significantly different based on the DBP genotype (P < 0.01 and P < 0.05, respectively). The people with Gc 1S-2 (5.73 +/- 2.57 microU/mL) and 1S-1S (5.30 +/- 3.46 microU/mL) had significantly higher fasting plasma concentrations than those with 1F-1F (2.84 +/- 1.67 microU/mL) (P < 0.01 and P < 0.03, respectively). There was no significant difference in plasma glucose concentration, body mass index, total cholesterol, triglyceride, and blood pressure. In conclusion, genetic variations of DBP are associated with insulin resistance in Japanese with normal glucose tolerance, which might contribute to the development of type 2 diabetes.

Asian People↗

PubMed2000

Facile synthesis of optically active gamma-lactones via lipase-catalyzed reaction of 4-substituted 4-hydroxybutyramides.

Lipase-catalyzed transesterification of racemic 4-substituted 4-hydroxybutyramides with succinic anhydride proceeded enantioselectively to afford (S)-succinic acid monoester and unreacted (R)-4-hydroxybutyramide derivative, which were separated easily by treatment with an alkaline solution. Both enantiomers were converted easily to optically active gamma-substituted gamma-butyrolactones.

4-Butyrolactone↗

PubMed2000

Analysis of the phospholipid hydroperoxide glutathione peroxidase mRNA in the rat spermatozoon and effect of selenium deficiency on the mRNA.

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a selenium (Se)-dependent glutathione peroxidase. It is reported that the relative PHGPx mRNA levels are much higher in the testis than in the other tissues. We have analyzed the existence and structure of the PHGPx mRNA in rat sperm and the changes in the level of the PHGPx mRNA after feeding with Se-deficient diets. We used 8-wk-old male Wistar strain rats given Se-adequate feed (control group, n = 5) and Se-deficient diets with marginal levels of Se (0.03 ppm or less) (Se-deficient group, n = 5) for 4 wk. The existence and level of the PHGPx mRNA in the cauda epididymal sperm, testis, and liver from the Se-adequate rats were analyzed by the reverse transcription-polymerase chain reaction and the Southern blotting method. As a result, the existence of the PHGPx mRNA was demonstrated in the cauda epididymal sperm as well as in the testis and liver. Moreover, the subtype of the PHGPx mRNA in the rat sperm was the mitochondrial-type mRNA, which included a region corresponding to the mitochondrial transfer leader sequence. These results imply that the intracellular localization of PHGPx may be regulated by the transcription level. On the other hand, there was no significant difference between the control group and the Se-deficient group in the Se level of the cauda epididymal sperm and the level of the PHGPx mRNA. In conclusion, it has been demonstrated that the PHGPx mRNA exists in rat sperm for the first time. The analysis of the PHGPx mRNA in the sperm would be a useful tool for investigating the disfunction caused by the disorder of the level or structure of the PHGPx in the sperm.

Animals↗

PubMed2000

Total spondylectomy for solitary spinal metastasis of the thoracolumbar spine: a preliminary report.

Eight cases of solitary spinal metastasis with neurological deficit in thoracolumbar spine in which total en bloc spondylectomy (TS) was performed by bisecting the affected vertebra through both pedicles using fine thread wire saws were reviewed. Patient age ranged from 40 to 78 (mean, 62) years. Primary lesions were in the lung (2), kidney (2), thyroid (3) and prostate (1). TS was performed through a posterior approach in 5 cases (T6-7, T12, L2, L2 and L2-3) and through a one-stage anterior and posterior combined approach in the others (L2, L3 and L4). The spine was reconstructed with a ceramic vertebral prosthesis and a pedicle screw fixation system in 5 cases, and with augmented anterior spinal instruments in 3 cases. There were neither surgical complications nor surgical mortality. All patients became ambulatory and pain-free after surgery. Histologically, a marginal surgical margin was achieved in only one case. The other 7 cases had intralesional margin at the osteotomized pedicles. Four patients died from causes unrelated to local recurrence 4 to 44 (mean, 19) months after surgery. Effectiveness of surgery was maintained until death in all 4 of these patients. Asymptomatic local recurrence occurred in 2 patients with renal cancer at 10 and 33 months after surgery. These preliminary results suggest that TS for solitary spinal metastasis can achieve good control of local recurrence without major complications and is clinically acceptable surgery.

Adult↗

PubMed2000

Influence of P-glycoprotein on the transport and metabolism of indinavir in Caco-2 cells expressing cytochrome P-450 3A4.

Caco-2 cells grown in the presence of 1alpha,25-di-OH vitamin D(3) (di-OH vit D(3)) were used as a model to evaluate the effects of P-glycoprotein (Pgp) efflux on CYP3A4-mediated metabolism of indinavir during intestinal absorption. Caco-2 cells grown under these conditions demonstrated significant CYP3A4 activity and maintained Pgp-mediated directional transport of indinavir. Metabolism of indinavir in the di-OH vit D(3)-treated cells correlated with the level of CYP3A activity and generated metabolites consistent with CYP3A4-mediated metabolism. During transport experiments, indinavir metabolites are selectively secreted into the apical compartment, consistent with Pgp-mediated efflux. Using formation of the most abundant metabolite, M6, as a marker for indinavir metabolism, we observed that the extent of indinavir metabolism is not significantly affected by the direction of indinavir transport or by inhibition of Pgp with cyclosporin A. However, because Pgp efflux results in higher indinavir transport in the basolateral-to-apical direction than in the apical-to-basolateral direction, the ratio of M6 produced normalized to the amount of drug transported across the monolayer was higher for apical-to-basolateral transport. Thus, Pgp efflux in a direction opposite to absorptive transport results in more metabolite produced per mole of drug that is absorbed. In summary, the results support a role of Pgp in increasing intestinal presystemic metabolism and in removal of CYP3A4-generated metabolites from the intracellular compartment.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

[Differential diagnosis between aneurysm and infundibular dilatation in the IC-PC region with 3D-CTA].

In cases of asymptomatic internal carotid-posterior communicating artery (IC-PC) protrusions, it is sometimes difficult to differentiate infundibular dilatation (ID) from aneurysm by digital subtraction angiography. We applied three-dimensional CT angiography (3D-CTA) in 32 cases of these IC-PC protrusions. SOMATOM PLUS 4 was used under such conditions as to provide images with high spatial resolution. The shaded surface display (SSD) method was adopted to reconstruct the 3D images because of its advantage in separating overlapped vasculature. We also made reference to source images and maximum intensity projection (MIP) to make sure of our diagnoses. In all cases including 4 aneurysms and 28 IDs, we were able to distinguish between ID and aneurysm. The accuracy of 3D-CTA was confirmed by 9 surgical cases. Our technique was as follows: 1) To inject a high dose of diluted contrast medium rapidly to smaller arteries for opacification of contrast medium. 2) To exclude neighboring useless structures except for the very close structures such as posterior clinoid process from the target image focusing on the IC-PC region. 3) To observe the reconstructed image of MIP and SSD from various angles. The contralateral and craniocaudal view were valuable. 4) To change the threshold level gradually and observe the configurational changes of the apex of protrusion. Poorly developed PcomA was mostly delineated at the optimum threshold level. Otherwise, the apex of protrusion remained spherical in an aneurysm and became pyramidal in shape in an ID when the threshold level was gradually decreased. In conclusion, 3D-CTA was a useful modality for IC-PC protrusions to distinguish between ID and aneurysm.

Aged↗

PubMed2000

Cytofluorometric nuclear DNA content analysis of breast tissues after frozen section diagnosis.

OBJECTIVE: To establish a suitable method for measurement of nuclear DNA content in breast tissues from frozen storage after frozen section diagnosis. STUDY DESIGN: For fundamental research, rat liver samples preserved in a deep freezer were used. Four protocols were used (1. fixation with 70% ethanol followed by naked nuclei preparation; 2. fixation with 10% neutral buffered formalin followed by naked nuclei preparation; 3. preparation for naked nuclei prior to fixation with 70% ethanol; and 4. preparation for naked nuclei prior to fixation with 70% neutral buffered formalin). For clinical research, 13 separate fresh frozen breast tissue samples were analyzed after frozen section diagnosis. One contained a malignant phyllodes tumor (MPT) consisting of 2 components, benign epithelial cells and malignant stromal cells; 3 were benign tumors containing fibroadenoma; and 9 cases were carcinomas, consisting of 5 scirrhous, 3 papillotubular and 1 mucinous. RESULTS: Protocols 1, 2 and 3 were not suitable methods for our purpose because remaining cytoplasm or cohesive nuclei were observed. In protocol 4 the cytoplasm was completely undetectable, and nuclei were suitably separated for nuclear DNA content measurement. Benign epithelial cell component nuclei presented a diploid pattern, and the malignant stromal cell component nuclei indicated a euploid pattern in MPT. All 3 cases of benign constituents in fibroadenoma showed a diploid pattern, as did the 3 carcinoma cases (1 mucinous, 1 scirrhous and 1 papillary). Four scirrhous and 2 papillary carcinomas showed an aneuploid pattern. CONCLUSION: Our findings show that it is possible to measure nuclear DNA content of human frozen storage tissues after frozen section diagnosis.

Animals↗

PubMed2000

Route-dependent nonlinear pharmacokinetics of a novel HIV protease inhibitor: involvement of enzyme inactivation.

L-754,394, a furanopyridine derivative, is an experimental HIV protease inhibitor. Previous studies from this laboratory have demonstrated that L-754,394 is cleared very rapidly in animals, and that this drug is a potent mechanism-based inactivator (suicide inhibitor) for CYP3A4 in human liver microsomes. Because L-754,394 is a high-clearance drug and an enzyme inactivator, it is expected that this drug will be subject to significant first-pass metabolism, and that the degree of enzyme inactivation will be dependent not only on the dose, but also on the route of administration. The purpose of this study is to examine the effects of dose and route of administration on the kinetics of L-754,394 using rats and dogs as animal models. In both rats and dogs, L-754,394 exhibited marked dose-dependent pharmacokinetics after i.v. and oral administration. Irrespective of i.v. or oral administration, the area under the plasma concentration-time curve from zero to infinity increased with dose in a greater than proportional manner. However, the magnitude of area under the plasma concentration-time curve from zero to infinity increase was much greater after oral dosing than after i.v. administration, indicating route-dependent pharmacokinetics. Data from in vitro and in vivo studies suggested that the dose- and route-dependent pharmacokinetics were due mainly to the inactivation (destruction) of the enzymes responsible for its own metabolism.

Administration, Oral↗

PubMed2000

Comparison of imidazole- and 2-methyl imidazole-containing farnesyl-protein transferase inhibitors: interaction with and metabolism by rat hepatic cytochrome P450s.

Methylation at the 2-position of the imidazole ring of IBN (I), a 1, 5-substituted imidazole-containing compound, was carried out to minimize its inhibition of rat cytochrome P450 (CYP)3A activity. The resulting analog 2-MIBN (II) exhibited an inhibitory potency 70-fold weaker (K(i) = 25 microM) than that of I (K(i) = 0.3 microM) toward CYP3A, the major rat liver microsomal P450 isoform(s) for the metabolism of I and II by rat liver microsomes in the presence of NADPH. The structural modification did not switch the major metabolic pathways for I and II, but significantly decreased the affinity of II to the metabolizing enzyme(s) as reflected by the difference in their K(i) values for CYP3A. Enzyme kinetic studies also demonstrated that I had a lower apparent K(m) (0.3 microM) than than II (18 microM), but an apparent V(max) 14 times lower than II. This finding indicates that methylation at the imidazole ring reduced the affinity of the compound to CYP3A, but increased the catalytic capacity, turning I as a substrate of low K(m) value but low capacity into a compound of high K(m) but high capacity for the metabolism. Our results suggest the significance of substrate concentration in comparing the metabolic stability of compounds with different kinetic parameters. Although higher intrinsic clearance is implied for I when the substrate concentration is below or close to its K(m) value, higher metabolic rate was constantly seen with II over micromolar range. The different kinetic parameters of I and II may also explain the observation that no significant difference in pharmacokinetic behavior was seen after an i.v. administration of I and II to the rat.

Alkyl and Aryl Transferases↗

PubMed2000

[Acute surgical and endovascular therapy for stroke: especially patients with brain infarction].

From January 1994 to December 1997, 845 patients with stroke were admitted to Hakodate Municipal Hospital. They consisted of 514 patients with brain infarction, 206 with brain hemorrhage, 121 with subarachnoid hemorrhage and 4 with intracranial hemorrhage from arteriovenous malformation. The clinical categories of brain infarction were as follows; atherothrombotic recognized in 158 patients, cardioembolic in 114, lacunar in 217 and other categories in 25. With regard to the cures of brain infarction in the acute phase, direct percutaneous transluminal angioplasty (direct PTA) was carried out on three patients with atherothrombotic infarction, immediate PTA on two, superselective fibrinolytic therapy on two, and STA-MCA anastomosis on three. In all, ten atherothrombotic patients (6.3%) were treated by acute surgical or endovascular therapy. On the other hand, superselective fibrinolytic therapy was carried out on 35 patients (30.7%) with cardioembolic infarction. There were no patients in the lacunar infarction group who were given acute surgical treatment. Neurological improvement after 24 hours was recognized in 4 patients (40%) of 10 with atherothrombotic infarction, and in 9 patients (25.7%) of 35 with cardioembolic infarction. However, symptomatic intracerebral hematoma was recognized in 4 patients (11.4%) with cardioembolic infarction. Indication for acute surgical or endovascular treatment for brain infarction was very limited because of the time factor from the onset to admission. It is suggested that neurosurgeons might enlighten citizens about the necessity for acute surgical or endovascular therapy for stroke.

Angioplasty, Balloon, Coronary↗

PubMed2000

Reliable differential diagnosis between osteosarcoma and regenerative bone cells in rats through simultaneous analysis of nuclear DNA content and size.

OBJECTIVE: To evaluate the difference between benign proliferative lesions of regenerative bone calluses and malignant tumors in rats by simultaneous analysis of nuclear DNA content and size. STUDY DESIGN: Nuclei were stained with DAPI and measured by cytofluorometry. Five regenerative bones and five osteosarcoma samples were used. Two-dimensional dispersion diagrams between relative nuclear DNA content and nuclear size were drawn up and their regression lines were compared. RESULTS: It was possible to distinguish between osteosarcomas and regenerative bones by simultaneous analysis of nuclear size and DNA content during the cell cycle. The results yielded coefficients of correlation and regression. All five regression lines of osteosarcomas were situated dramatically higher on dispersiongrams than those of regenerative bones. CONCLUSION: Differential diagnosis between regenerative lesions and malignant tumors may now be possible using simultaneous measurement of nuclear DNA content and size.

Animals↗

PubMed2000

[Common carotid artery dissection propagated from acute aortic dissection: a case successfully treated by PTA].

We reported a rare case, which was successfully treated by PTA, of right common carotid artery dissection propagated from acute aortic dissection (AAD) type A. A 45-year-old male with a past history of hypertension and an artificial graft replacement of the abdominal aorta due to AAD type B, 7 years ago, was brought into our hospital by ambulance 30 minutes after an attack of fainting and left hemiparesis. On admission, the patient complained not of chest pain or left hemiparesis, but nausea. At that time his consciousness level was JCS 1. During examinations, he had the same attack twice and his consciousness level deteriorated to JCS 2. Brain MRI showed no abnormality, but cervical MRA did not visualize the right carotid artery and thoracic CT depicted acute aortic dissection including branches of the aorta. Emergent angiography disclosed that the dissecting 99% stenosis of the right common carotid artery had developed from AAD type A with poor collateral blood flow. PTA was carried out 8 times and reduced the residual stenosis to about 50% with shortened circulation time. The patient's consciousness disturbance improved. After the replacement of the whole aortic arch in an artificial graft, the residual stenosis disappeared. The patient recovered without neurological deficit but right frontal silent embolic infarction caused by the artificial graft replacement was detected. AAD is a catastrophic illness and sometimes accompanied by devastating ischemic cerebral disease (ICD) because of propagation of dissecting to extracranial vessels. This is the first report that shows the efficacy of PTA for treatment of ICD associated with AAD.

Acute Disease↗

PubMed2000

[Pursuit of economic efficiency in the hospital laboratory--full automatic re-test system of clinical chemistry, hematology, immunology and cost control system].

Further business improvement is requested due to finance-based fluctuation and the influence of the revision in the medical treatment law. Therefore, new laboratories are needed. To achieving this in our hospital, economic efficiency is being pursued. The first issue is the use of space, the second issue is labor-saving. The third issue is the simplification of business procedures. There is individual quality control by the zonal verification method that we developed, as well as the quality control of the batch method using controlled substances. The four issue is cost control. By controlling the delivery and use of reagents and materials including the term of validity control, we made an effort to abolition defective stock. The fifth issue is correspondence to circulation style society. The disposal of laboratory garbage is a major issue. We controlled garbage that occurs unnecessarily. Furthermore, we are improving the demand for reagents that exceeds the specification and use reagent containers.

Automation↗

PubMed1999

Posterior stabilization of degenerative lumbar spondylolisthesis with a Leeds-Keio artificial ligament. A biomechanical analysis in a porcine vertebral model.

STUDY DESIGN: The biomechanical characteristics of the Leeds-Keio artificial ligament (Neoligament LTD, England) were assessed in the posterior stabilization of degenerative lumbar spondylolisthesis in a porcine vertebral model. OBJECTIVES: To evaluate the biomechanical properties of this nonrigid system immediately after instrumentation and during cyclic loading. SUMMARY OF BACKGROUND DATA: Mochida et al reported an innovative method of posterior stabilization in which the Leeds-Keio artificial ligament was used as a nonrigid instrument. Since 1990, this system has been used successfully to treat a select group of patients with degenerative lumbar spondylolisthesis. METHODS: Five porcine motion segments (L4-L5) were tested in the intact, destabilized, and Leeds-Keio-instrumented conditions. Specimens were loaded in flexion and extension, and construct stiffness was measured during the initial loading cycle and at 250 cycle intervals for 1500 cycles. RESULTS: Biomechanical stability in the model of degenerative lumbar spondylolisthesis was inferior to that in the controls. The instability in the Leeds-Keio group significantly improved immediately after placement and after 1500 cycles. CONCLUSIONS: This system is effective in initially stabilizing an unstable degenerative lumbar spondylolisthesis model and maintains its stabilizing effect during cyclic loading. Therefore, it can offer patients with degenerative lumbar spondylolisthesis in the late static stage several advantages over other treatment methods.

Animals↗

PubMed1999

Anterior decompression with single segmental spinal interbody fusion for lumbar burst fracture.

STUDY DESIGN: The clinical and radiologic records for seven patients with lumbar burst fracture who underwent anterior decompression with single segmental interbody fusion were reviewed. OBJECTIVE: To determine the clinical results obtained with this method and its influence on the intervertebral disc degeneration inferior to the fusion. SUMMARY OF BACKGROUND DATA: Some patients with Denis' type B fracture can tolerate one-segment anterior fusion. However, there is no reliable information in the literature regarding the juxtafusional disc degeneration after one-segment fusion. METHODS: Seven patients with type B lumbar burst fractures, including four with cleavage fracture of the lower endplate, underwent anterior single segmental fusion; three patients underwent surgery with no instrumentation, and four underwent surgery with Kaneda instrumentation. The mean follow-up period lasted 85 months. The kyphosis angle and inferior intervertebral disc height adjacent to the fusion were measured before and after surgery. Pain and working status were evaluated using the scales proposed by Denis et al. RESULTS: Significant correction loss was obtained 1 year after surgery in the patients in whom no instrumentation was used (7.3 +/- 0.6 degrees), compared with the correction loss in patients whose surgery included the use of instrumentation (0.3 +/- 0.5 degree; P = 0.00001). No further correction losses were seen in either group at the final follow-up examination. No marked reduction in disc height was observed in any patient, including the four patients with cleavage fracture of the lower endplate. All patients returned to their previous occupation; five patients were rated as P1 (no pain) and W1 (returned to heavy labor), and two patients were rated as P2 (minimal pain) and W2 (return to heavy labor with lifting restrictions) at the final follow-up examination. CONCLUSIONS: There was slight correction loss within 1 year when no instrumentation was used, but this deformity did not affect the clinical results. The results provided no evidence that cleavage fracture of the lower endplate accelerates degeneration of the adjacent intervertebral disc.

Adolescent↗

PubMed1999

Oxidative DNA damage in diabetes mellitus: its association with diabetic complications.

AIMS/HYPOTHESIS: Augmented oxidative stress induced by hyperglycaemia possibly contributes to the pathogenesis of diabetic complications. Oxidative stress is known to increase the conversion of deoxyguanosine to 8-oxo, 2'-deoxyguanosine in DNA. To investigate the possible contribution of oxidative DNA damage to the pathogenesis of diabetic complications, we measured the content of 8-oxo, 2'-deoxyguanosine in the urine and the blood mononuclear cells of Type II (non-insulin-dependent) diabetic patients. METHODS: We studied 53 Type II diabetic patients and 39 age-matched healthy control subjects. We assayed 8-oxo, 2'-deoxyguanosine by HPLC-electrochemical detection method. RESULTS: The content of 8-oxo, 2'-deoxyguanosine in the urine and the mononuclear cells of the Type II diabetic patients was much higher than that of the control subjects. Urinary 8-oxo, 2'-deoxyguanosine excretion and the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells from the diabetic patients with complications were higher than those from the diabetic patients without complications. Urinary excretion of 8-oxo, 2'-deoxyguanosine was significantly correlated with the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells. The 8-oxo, 2'-deoxyguanosine content in the urine and mononuclear cells was correlated with the haemoglobin A1c value. CONCLUSIONS/INTERPRETATION: This is the first report of a direct association between oxidative DNA damage and the complications of diabetes. The augmented oxidative DNA damage in diabetes is speculated to contribute to the pathogenesis of diabetic complications.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed1999

Recombinant vaccinia viruses expressing an immunodominant epitope of HIV-1 envelope protein within an influenza hemagglutinin cassette predominantly prime epitope-specific CD8(+) CTL.

We constructed recombinant vaccinia viruses (RVV) expressing a 15-residue peptide (P18IIIB; RIQRGPGRAFVTIGK) of gp160 envelope protein from a human immunodeficiency virus type-1 (HIV-1) IIIB isolate using an H1 influenza virus hemagglutinin (HA) gene cassette. Immunofluorescent tests with antisera against both H1N1 influenza virus and P18IIIB localized chimeric HA molecules comprising influenza virus HA and P18IIIB peptide intracellularly, but the P18IIIB could not be seen on the outer surfaces of infected cells though weak fluorescence was detected regarding HA molecule. Consistent with these findings, Western blotting confirmed the expression of a polypeptide of about 74-kDa protein representing chimeric HA molecule in the infected cells. These recombinants markedly primed CD8(+) cytotoxic T lymphocytes (CTL) specific for P18IIIB as well as HA protein of the influenza virus, but failed to elicit P18IIIB-specific antibody despite stimulating production of HA-specific antibody. In addition, the P18IIIB-specific CTL could strongly lyse target cells expressing the whole HIV-1 envelope gene of IIIB strain. Thus, the influenza virus chimeric HA cassette vector system used in the present study appeared to be a useful tool for constructing vaccine candidates which will predominantly prime CD8(+) CTL specific for immunodominant determinants of various infectious agents.

Amino Acid Sequence↗