Feasibility study of neoadjuvant chemotherapy with docetaxel, cisplatin, and fluorouracil (DCF) for clinical stage II/III esophageal squamous cell carcinoma

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Background: In JCOG 9907, neoadjuvant chemotherapy with cisplatin and 5-fluorouracil (CF) improved overall survival without additional serious adverse events in treating stage II/III esophageal squamous cell carcinoma (ESCC). However, ESCC patient survival remains unsatisfactory. We conducted a feasibility study of neoadjuvant chemotherapy with docetaxel plus CF (DCF) for clinical stage II/III ESCC.

Methods: Eligibility criteria included clinical stage II/III (non-T4) ESCC, PS 0–1, and age 20–70 years. Chemotherapy consisted of a 1-h infusion of docetaxel at 70 mg/m2 and 2-h infusion of cisplatin at 70 mg/m2 (day 1), and continuous infusion of 5-FU 750 mg/m2 (days 1 to 5). Antibiotic prophylaxis on days 5 to 15 was mandatory. This regimen was repeated every 3 weeks (maximum 3 cycles) until unacceptable toxicity, patient refusal, or disease progression was observed. After chemotherapy completion, transthoracic esophagectomy with extended (> D2) lymphadenectomy was performed. The primary endpoint was the completion rate of protocol treatment.

Results: From July 2009 to Feb 2010, 34 patients were enrolled, including 2 ineligibles. The 32 eligibles had a median age of 61 (range 36–70; male/female: 30/2), with PS0/1 of 20/12 and cStage IIA/IIB/III of 6/8/18. During chemotherapy, the most common grade-3 or -4 toxicities were neutropenia (88%), febrile neutropenia (3%), anorexia (9%), and stomatitis (6%). Thirty-one (97%) patients underwent surgery. The protocol completion rate was 87.5% (28/32). No treatment-related death was observed, and the operative morbidity incidence was comparable to those in previous studies. According to RECIST, the overall response rate was 61.5% after DCF completion. Primary-lesion pathological complete response was achieved in 26% of patients (8/31) who underwent esophagectomy.

Conclusions: Neoadjuvant DCF was well tolerated. Although these data are preliminary, the protocol is highly promising and warrants further investigation.

No significant financial relationships to disclose.

Distributions of FcγRIIa-131 and FcγRIIIa-158 polymorphisms and clinical response to cetuximab in Japanese patients with metastatic colorectal cancer (mCRC)

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Background: Polymorphisms in fragment C receptor (FcγR) are expected as a predictive biomarker of cetuximab (Cmab). Previous studies have convincingly confirmed the distributions (dists) of FcγR polymorphisms in Western population and shown the existence of linkage disequilibrium (LD) between FcγRIIa and FcγRIIIa polymorphisms. Meanwhile, the dists in Asian population have been unknown but a few studies for non-cancer patients have suggested the difference in dists between Asian and Western populations. We investigated the dists of FcγR polymorphisms and their association with clinical response to Cmab in Japanese mCRC patients.

Methods: Ninety-three patients with irinotecan/oxaliplatin/5-FU-refractory mCRC and treated by Cmab plus irinotecan or Cmab monotherapy were retrospectively registered from 8 centers in Japan. FcγR polymorphisms were determined from genomic DNA extracted from peripheral blood samples based on the Multiplex allele-specific PCR method. Comparisons according to FcγR polymorphisms were evaluated using Fisher's exact test for response rate (RR) and log-rank test for progression-free survival curves (PFS).

Results: The dists of FcγRIIa HH/HR/RR and FcγRIIIa VV/VF/FF were 68/30/2% and 4/40/56%, respectively (Table). The absence of LD between FcγRIIa and FcγRIIIa polymorphisms was confirmed (GENEPOP, p=0.526; Linkdis, p=0.146). Of 74 patients with KRAS wild-type and treated by Cmab plus irinotecan, no difference according to FcγR polymorphisms was observed in either RR (IIa: HH 37% vs. HR/RR 36%, p=1.00; IIIa: VV/VF 39% vs. FF 35%, p= 0.81) or PFS curves (IIa: HH vs. HR/RR, p=0.84; IIIa: VV/VF vs. FF, p=0.09). Similar results were seen in patients treated by cetuximab monotherapy.

Conclusions: This study clarified an ethnic difference in the frequencies of FcγR polymorphisms. Associations between the polymorphisms and clinical response to Cmab did not reach a statistical significance.

[Table: see text]

No significant financial relationships to disclose.

Clinical outcome in patients with metastatic colorectal cancer harboring KRAS p.G13D mutation treated with cetuximab

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Background: Metastatic colorectal cancer patients with KRAS codon 12 or 13 mutated tumors are presently excluded from treatment with cetuximab (Cmab). On the other hand, a few patients who have mutated KRAS status occasionally respond to Cmab. The tumors of those patients predominantly had codon 13 mutation, and all codon 13 responder have mutation of p.G13D. We now compared the efficacy of Cmab among patients with p.G13D- mutant, other KRAS mutant and KRAS wild-type colorectal cancer.

Methods: The patients from 9 Japanese institutions were retrospectively collected and analyzed. All patients were refractory to fluoropyrimidine, oxaliplatin and irinotecan, and were treated with Cmab and irinotecan combination regimen. Response rate (RR), progression-free survival (PFS) and overall survival (OS) were calculated respectively according to KRAS status.

Results: Ninety four patients were treated with combination therapy. Among 94 cases, 7 cases were p.G13D-mutant KRAS, 23 cases were other mutant KRAS and 63 cases were wild-type KRAS. Baseline characteristics by each subset were well-balanced. While one partial response (PR) and 4 stable diseases (SD) cases were found in 7 p.G13D-mutated cases, no PR was found in other KRAS mutated cases. Median PFS of the patients with p.G13D-mutant, other KRAS mutant and KRAS wild-type were 4.5 months (95%CI 1.7-), 2.3 months (95%CI 1.9-4.3), 4.6 months (95%CI 3.5-6.5) respectively. And median OS of the patients with p.G13D- mutant, other KRAS mutant and KRAS wild-type were 9.3months (95%CI 8.5- 11.8), 7.4 months (95%CI 4.5-9.4), 12.2 months (95%CI 8.7-19.8) respectively. Although statistical significance was not found between the two mutated groups, there are trends that the patients with p.G13D-mutant may have received better clinical benefits from Cmab than the patients with other KRAS mutant.

Conclusions: Cmab may have therapeutic benefit in the patients with KRAS p.G13D-mutant colorectal cancer although further evaluation is warranted.

No significant financial relationships to disclose.

Tazobactam/piperacillin for moderate-to-severe pneumonia in patients with risk for aspiration: comparison with imipenem/cilastatin

BACKGROUND

Treatment of aspiration pneumonia is becoming an important issue due to aging of populations worldwide. Effectiveness of tazobactam/piperacillin (TAZ/PIPC) in aspiration pneumonia is not clear.

PURPOSE

To compare clinical efficacy between TAZ/PIPC (1:4 compound) and imipenem/cilastatin (IPM/CS) in patients with moderate-to-severe aspiration pneumonia.

PATIENTS AND METHODS

In this open-label, randomized study either TAZ/PIPC 5 g or IPM/CS 1 g was intravenously administered every 12 h to patients with moderate-to-severe community-acquired aspiration pneumonia or nursing home-acquired pneumonia with risk for aspiration pneumonia for average 11 days. The primary outcome was clinical response rate at the end of treatment (EOT) in validated per-protocol (VPP) population. Secondary outcomes were clinical response during treatment (days 4 and 7) and at the end of study (EOS) in VPP population, and survival at day 30 in modified intention-to-treat (MITT) population.

RESULTS

There was no difference between the groups in primary or secondary outcome. However, significantly faster improvement as measured by axillary temperature (p < 0.05) and WBC count (p = 0.01) was observed under TAZ/PIPC treatment. In patients with gram-positive bacterial infection, TAZ/PIPC was more effective at EOT in VPP population (p = 0.03).

CONCLUSION

TAZ/PIPC is as effective and safe as IPM/CS in the treatment of moderate- to-severe aspiration pneumonia.

MAC-CCD system: a novel lymphocyte microwell-array chip system equipped with CCD scanner to generate human monoclonal antibodies against influenza virus

We previously developed a lymphocyte microwell-array system, which effectively detects antigen-specific B-cells by monitoring intracellular Ca(2+) mobilization at the single-cell level with a fluorescent Ca(2+) indicator, fluo-4. However, it is difficult for the system to perform time-lapse monitoring. Here, we developed a novel method, a lymphocyte microwell-array chip system equipped with a charge-coupled device (CCD) time-lapse scanner (MAC-CCD system), for monitoring intracellular Ca(2+) mobilization. The MAC-CCD system is able to monitor intracellular Ca(2+) mobilization of more than 15,000-20,000 individual live B-cells every 10 s. In addition, we adopted a correlation method in a MAC-CCD system, which enabled us to detect B-cells with a frequency of as few as 0.046%. Furthermore, we succeeded in obtaining six influenza nucleoprotein-specific human monoclonal antibodies from the peripheral blood of influenza-vaccinated volunteers. These results demonstrate that the MAC-CCD system with a correlation method could detect very rare antigen-specific B-cells.

Surgery for infective endocarditis: determinate factors in the outcome

AIM

The appropriate operative procedures for treatment of infective endocarditis (IE) are still controversial. The authors reviewed their own operative results focusing on preoperative risk factors, intraoperative findings and operative procedures.

METHODS

The authors reviewed the cases of 40 adult patients who had undergone surgery since 1999. The mean age of patients was 58 years ranging from 31 to 78 including 30 males and 10 females. Thirty-three patients had native valve endocarditis (NVE) and the remaining seven patients had prosthetic valve endocarditis (PVE). Diseased lesions were located in the mitral valve (MV) in 21 patients, aortic valve in 15 and mitral plus aortic valves in four. Twenty-eight patients (70%) were operated on during the active phase of IE. Streptococcus, Staphylococcus and Enterococcus species were predominant in the bacterial examination.

RESULTS

Active vegetation was observed in 26 (65%) patients. Perforation of valve leaflets was observed in 11 (28%) cases. Changes of native MV leaflet were mild in 8 (40%) out of 20, which seemed to be reparable, while, changes of the native aortic valve leaflet were moderate to severe in 13 (87%) out of 15 patients. Valvular annuls were involved in the infection in 17 (43%) patients. Of the 33 NVE patients, prosthetic valve replacement was performed in 29 patients including 19 mitral and 15 aortic valves. MV plasty was performed in 4 patients. In seven PVE patients, prosthetic MV replacement was performed twice. In the aortic group, three patients underwent aortic root translocation, The Ross procedure and standard root replacement were performed respectively. Four patients died after surgery including one NVE case and three PVE cases. Three PVE patients who underwent aortic root translocation or the Ross procedure survived. The hospital mortality of NVE and PVE surgery was 3% and 43% (P<0.01), respectively. By univariant analysis, there were no significant correlations between operative results and preoperative factors such as bacteria, infective phase, cardiac failure, renal failure, sepsis or brain morbidity. The only significant factor on hospital mortality was PVE. Three patients died of non-cardiac diseases during the follow-up period.

CONCLUSION

Operative results of NVE were good after complete resection of infective sites including valve annulus. Both valve replacement and plasty were available for NVE patients. In PVE, new strategies are indispensable and aortic root translocation or the Ross procedure should be a treatment of choice.

Relationship of elevated casual blood glucose level with coronary heart disease, cardiovascular disease and all-cause mortality in a representative sample of the Japanese population. NIPPON DATA80

AIMS/HYPOTHESIS

High fasting blood glucose is one of the well-known risk factors for CHD. However, in certain settings, patients cannot always be expected to fast. For example, community screenings for cardiovascular disease (CVD) risk factors in Japan are performed under non-fasting conditions to achieve high participation rates. Thus, we examined a representative cohort of the Japanese population (n=9,444, follow-up period 17.3 years) to clarify whether high casual blood glucose (CBG) can predict CVD mortality.

METHODS

We defined CBG groups as follows: high CBG >or= 11.1 mmol/l or participants with a history of diabetes mellitus; borderline high, 7.77 <or= CBG<11.1 mmol/l; higher normal, 5.22 <or= CBG<7.77 mmol/l); and lower normal, CBG<5.22 mmol/l. The multivariate-adjusted hazard ratios (HRs) for CHD, CVD and all-cause mortality were calculated.

RESULTS

The crude CHD mortality rate was 0.84 per 1,000 person-years. Age- and sex-adjusted HRs for CHD mortality were high among participants with CBG levels >or= 7.77 mmol/l, regardless of time since last meal. Multivariate-adjusted HRs (95% CI) of CHD mortality in high and borderline high CBG groups were 2.62 (1.46-4.67) and 2.43 (1.29-4.58), respectively. Similar results were observed for both CVD and all-cause mortality. Even within the normal blood glucose range, each 1 mmol/l increase in CBG was associated with a statistically significant increase in the HR for CVD mortality (1.12, 95% CI 1.02-1.22). Population-attributable fractions of the combined groups of high and borderline high CBG for CHD, CVD and all-cause mortality were 12.0, 4.9 and 3.5%, respectively.

CONCLUSIONS/INTERPRETATION

Increases in CBG, even within the normal range, predict CVD mortality.

A novel mutation in the von Hippel-Lindau tumor suppressor gene identified in a Japanese family with pheochromocytoma and hepatic hemangioma

Von Hippel-Lindau (VHL) syndrome is a neoplastic syndrome caused by a mutation in the VHL gene. There is a discrepancy between the phenotypes of human VHL syndrome and VHL gene-disrupted mouse models. A heterozygous VHL gene-disrupted model (vhl +/-) developed hepatic vascular lesions; in contrast, hepatic hemangioma is a rare manifestation of human VHL syndrome. We identified a novel mutation (P154S) in the VHL gene in a Japanese family with pheochromocytoma. One of the members demonstrated hepatic hemangiomas, suggesting that there may be a relationship between the mutation of the VHL gene and hepatic vascular lesions, even in humans.

Hot spring bath and Legionella pneumonia: an association confirmed by genomic identification

A 59-year-old man developed pneumonia 9 days after bathing in a hot spring spa. Bilateral shadows on his chest radiograph rapidly progressed after admission. He was successfully treated with erythromycin and rifampicin. Legionella pneumophila serogroup 6 was recovered from an intratrachial specimen and a significant elevation was observed in a paired indirect fluorescent antibody to Legionella. Persistent slight fever and chest rentogenographic shadows resolved after administering low-dose prednisolone to treat organizing pneumonia shown by transbronchial lung biopsy. The same serotype of Legionella was recovered from the water of the hot spring spa where the man had bathed. When the extracted DNA of these two strains showed identical restriction fragments by pulsed-field gel electrophoresis, we had direct evidence that hot spring spas can be a source of Legionella pneumonia.

Plant regeneration from cell suspension-derived protoplasts of Primula malacoides and Primula obconica

Protoplasts were isolated from cell suspension cultures of Primula malacoides cv. 'Lovely Tokyo' and P. obconica cv. 'Aalsmeer Giant White'. P. obconica protoplasts were embedded in 0.1% (w/v) gellan gum-solidified discs comprising MS medium supplemented with 3 mg/l of 2,4-D or picloram, 0.1 mg/l of zeatin, 0.2 M glucose and 0.2 M mannitol, and surrounded by a liquid medium of the same composition except for the addition of 0.1% (w/v) activated charcoal. The protoplasts formed visible colonies, which were transferred to the regeneration medium containing 30 g/l of sucrose, 0.1 mg/l of picloram and 2 mg/l of zeatin for shoot induction. P. malacoides protoplasts formed visible colonies when cultured in disc culture using 0.1% (w/v) gellan gum-solidified MS medium containing 5 mg/l of 2,4-D, 1 mg/l of NAA, 0.1 mg/l of zeatin and 0.4 M glucose. Small calli were transferred to MS medium supplemented with 5 mg/l of zeatin for shoot regeneration. The shoots of both species readily rooted on plant growth regulator-free 1/2 MS medium and successfully acclimatized to greenhouse conditions. The protoplast-derived plants showed some alterations in morphological characteristics from those of the in-vitro-germinated control plants.

Low-dose continuous indomethacin in early days of age reduce the incidence of symptomatic patent ductus arteriosus without adverse effects

We conducted a comparative study to evaluate whether the low-dose continuous indomethacin therapy in the early days of age would reduce incidence of the symptomatic patent ductus arteriosus (PDA) without the adverse effects. Thirty-seven infants were in the historical comparison group, and 39 infants were given low-dose indomethacin continuously (0.004 mg/kg/h) from 6-12 postnatal hours until the recognition of closing PDA. Low-dose continuous indomethacin significantly decreased the incidence of symptomatic PDA at 5 days of age (p < 0.01) as compared with the historical comparison group. There was no episode of decreasing urinary output and necrotizing enterocolitis in the indomethacin group. We conclude that the low-dose continuous indomethacin therapy results in decreasing the incidence of symptomatic PDA without significant adverse reactions.

Aggressive neoplastic plasma cell growth with MLL gene rearrangement after high-dose therapy with autologous stem cell support for multiple myeloma

We report a case of a patient with IgA kappa multiple myeloma (MM) mobilized with etoposide and subsequently receiving high-dose melphalan (HDM) with stem cell support. She relapsed rapidly post transplantation. Southern blot and fluorescent in situ hybridization analysis showed MLL gene rearrangement in the myeloma cells, which was not detected in the sample at diagnosis or in the PBSC harvested with etoposide plus G-CSF. These observations suggest that clonal rearrangement of the MLL gene is caused by etoposide. Patients with MM undergoing HDM with stem cell rescue may be at an increased risk of not only secondary leukemia, but also secondary genetic abnormalities in myeloma cells, especially those receiving priming with etoposide for peripheral blood stem cell collection.

Effectiveness and safety of mutant Escherichia coli heat-labile enterotoxin (LT H44A) as an adjuvant for nasal influenza vaccine

The effectiveness and safety of mutant Escherichia coli heat-labile enterotoxin, LT H44A (His to Arg substitution at position 44 from the N-terminus of the A1 fragment of the A subunit) as an adjuvant for nasal influenza vaccine were examined. (1) When 0.2 microg of LT H44A, together with 0.2 microg of influenza A/PR/8/34 virus (PR8, H1N1) vaccine, was administered intranasally into BALB/c mice (twice, 4 weeks apart), anti-PR8 hemagglutinin (HA) IgA and IgG antibody (Ab) responses were induced at levels that were sufficient to provide either complete protection against infection with a small volume of PR8 virus suspension or partial protection against infection with a lethal dose of the suspension. The dose of the mutant LT and vaccine used here (0.2 microg/ 20 g doses mouse) corresponded to the estimated dose per person, i.e. 0.1 mg/10 kg body weight. (2) Using these vaccination conditions, no additional total IgE Ab responses were induced. (3) The mutant was confirmed to be less toxic than the native LT when the toxicity was analyzed either using Y1 adrenal cells in vitro (1/483 EC(50)) or by an ileal loop test. (4) One hundred micrograms of the mutant, administered intranasally or intraperitoneally into guinea-pigs (Heartley strain, 0.3-0.4 kg), caused no body-weight changes 7 days after administration, although 100 microg of the native LT administered intraperitoneally caused death in all guinea-pigs due to diarrhea within 2 days. The intranasal administration of 100 microg of the mutant resulted in almost no pathological changes in the nasal mucosa 3 days after administration. These results suggest that LT H44A, which can be produced in high yields in an E. coli culture (about 5 mg/l), could be used as one of the effective and safe adjuvants for nasal influenza vaccine in humans.

Body-force effect on the lateral movement of cellular flames at low Lewis numbers

The body-force effect on the lateral movement of cellular flames is studied by unsteady calculations of reactive flows at low Lewis numbers. We employ the compressible Navier-Stokes equation including chemical reaction to take account of the hydrodynamic effect caused by thermal expansion. A sinusoidal disturbance with the linearly most unstable wavelength is superimposed on a plane flame to simulate the formation of a cellular flame. The superimposed disturbance grows initially with time, and then the flame front changes from a sinusoidal to a cellular shape. After the cell formation, the cellular flame moves laterally at Lewis numbers lower than unity. The reason is that the diffusive-thermal effect, and the nonlinear effect of the flame front, play a primary role in the appearance of the lateral movement of cells. The body-force effect has a great influence on the lateral velocity of cells. When flames are propagated upward, the lateral velocity decreases as the acceleration increases, even though the body-force effect has a destabilizing influence. When flames are propagated downward, on the other hand, the lateral velocity takes a maximum value at the specific acceleration and decreases with an increase in acceleration. The dependence of lateral velocity on the acceleration is due to the augmentation and diminution in maximum flame temperature and to the broadness and narrowness of a high-temperature region behind a convex flame front.

Protection against influenza B virus infection by immunization with DNA vaccines

Protection against a lethal influenza B virus infection was examined in BALB/c mice immunized with plasmid DNAs encoding hemagglutinin (HA), neuraminidase (NA and NB) and nucleoprotein (NP) from the B/Ibaraki/2/85 virus. Each DNA vaccine was administered twice, 3 weeks apart, at a dose of 1 microg per mouse by particle-mediated DNA transfer to the epidermis (gene gun) or at a dose of 30 microg per mouse by electroporation into the muscle. Three weeks after the second vaccination, the mice were challenged with a lethal dose of homologous virus. HA and NA DNAs conferred complete protection against the lethal viral challenge, whereas NB and NP DNAs failed to provide protection against infection. Furthermore, protection in different strains of mice, BALB/c, B10 and C3H, immunized with HA and NA DNAs was compared. Both HA and NA DNAs conferred complete protection against the lethal challenge in all the tested mouse strains. These results suggest that both the HA and NA molecules can be used as vaccine components to provide effective protection against influenza B virus infection.

Cross-protection against a lethal influenza virus infection by DNA vaccine to neuraminidase

Cross-protection against a lethal influenza virus infection was examined in BALB/c mice immunized with plasmid DNAs encoding the neuraminidase (NA) from different subtype A viruses. Each NA-DNA was administered twice, 3 weeks apart, at the dose of 1 microg per mouse by particle-mediated DNA transfer to the epidermis (gene gun) or at a dose of 30 microg per mouse by electroporation into the muscle. Three weeks after the second vaccination, the mice were challenged with lethal doses of homologous or heterologous viruses and the ability of each NA-DNA to protect the mice from influenza was evaluated by determining the lung virus titers, body weight and survival rates. The H3N2 virus NA-DNA conferred cross-protection against lethal challenge with antigenic variants within the same subtype, but failed to provide protection against infection by a different subtype virus (H1N1). The degree of cross-protection against infection was related to titers of the cross-reacting antibodies. These results suggest that NA-DNA can be used as a vaccine component to provide effective protection against infection not only with homologous virus but also with drift viruses.

Protection against influenza virus infection in mice immunized by administration of hemagglutinin-expressing DNAs with electroporation

Electroporation for the transfer of plasmid DNA encoding influenza virus hemagglutinin (HA) into muscle or nasal mucosa was tried in BALB/c mice to examine the efficacy of this method for inducing anti-HA immune responses and providing protection against homologous A/PR/8/34 (PR8) virus infection. Mice were immunized by two injections, 3 weeks apart, of HA-DNA with electroporation into the muscle wherein a pair of electrode needles was inserted to deliver the electric pulses. One or 3 weeks after the immunization, the mice were infected with a lethal dose of the PR8 virus. Ten micrograms or more of HA-DNA/dose induced strong serum anti-HA IgG antibody (Ab) responses, in which both IgG1 and IgG2a were predominant, and weak cytotoxic T lymphocyte responses. These immune responses were sufficient to provide efficient protection against the lethal infection. In addition, mice were immunized by dropping HA-DNA (12 microg) three times, 2 weeks between each dose into nostrils where each of two electrode needles was placed on the right nostril or the palate. One week after the immunization, the mice were infected with a sublethal dose of the PR8 virus. The DNA immunization by electroporation provided reduced nasal virus titers, in parallel with a relatively high levels of serum anti-HA IgG Ab and a slight nasal anti-HA IgA Ab production. The intranasal administration of cholera toxin before HA-DNA immunization by electroporation enhanced the nasal IgA Ab production together with enhancement of the efficiency of protection. These results suggest that electroporation can be used as one of the efficient gene delivery systems for the transfer of influenza DNA-vaccine into muscle or nasal mucosa to provide protection against influenza virus infection.

Protection against influenza virus infection by nasal vaccination in advance of sublethal irradiation

The effect of sublethal gamma-ray irradiation on the protection conferred by a nasal influenza vaccine was investigated in BALB/c mice. A radiation dose of 7 Gy was selected as the sublethal dose as this caused exacerbation of the influenza but was not lethal in the mouse model. Mice were irradiated 7 days before, on the same day as, and 7 days after, administration of a nasal influenza vaccine, and were then infected with a lethal dose of the virus 4 weeks after vaccination. Almost all mice irradiated 7 days before or on the same day as vaccination died from viral pneumonia around 7 days after the challenge infection, whereas all mice irradiated 7 days after vaccination survived with no sign of infection. In mice irradiated 7 days after vaccination, both local anti-viral IgA and systemic IgG antibodies were produced in parallel with a marked reduction in lung viral titer, although no antibody production and no reduction in lung viral titer were detected in mice irradiated 7 days before, or on the same day as, vaccination. These results clearly demonstrate that vaccination with influenza virus before irradiation can protect mice from subsequent infection. This may be applicable to patients due to receive sublethal irradiation for bone marrow transplantation.